2008-2009 Fellows of the University of Texas
Southwestern Doris Duke
Clinical Research Fellowship Program for Medical Students
(UT Southwestern-Doris Duke-CRF)
Marcus H. Bell
University of South Alabama
Mentor: John Minna, M.D.
Hamon Center for Therapeutic Oncology
Genetic Signature for Radioresponse in NSCLCs
Background:
After surgery, radiotherapy is frequently offered as a first line of treatment for patients with non-small cell lung carcinoma. However, a significant number of patients fail to respond to radiotherapy due to marked radio-resistance exhibited by their tumors. Our primary interest is to understand the mechanisms of tumor resistance to radiotherapy and develop strategies to radiosensitize tumors by targeting specific molecular determinants of tumor radioresistance.
Project Description:
We employ non-small cell lung cancer (NSCLC) as a model system to interrogate a panel of 50-75 different patient-derived NSCLC cell lines for their responses to radiation. The objective is to develop and validate genetic signatures for radioresponse by comparing base-line and radiation-induced gene, protein, and micro-RNA expression profiles and promoter methylation patterns between radio-resistant and radiosensitive cell lines. The goal is to develop a diagnostic tool based on genetic signature of radioresponses to radiotherapy to predict radioresitance in NSCLCs from patients and rationalize treatment.
This project is closely linked to a similar program in the Hamon Cancer Center
for Therapeutic Oncology which has developed genetic signatures for tumor response
to various chemotherapeutic agents. A related goal of the project is to identify
markers that correlate chemo-resistance with radio-resistance. Such markers
could represent potential targets for sensitizing NSCLC tumors to radiation
therapy.
Christopher Cano
UT Southwestern
Mentor: Don Rockey M.D.
Division of Liver and Digestive Diseases
Occult Gastrointestinal Bleeding caused by Portal Hypertensive Gastropathy in Patients with Cirrhosis
Purpose: hypothesis and aims
Our hypothesis is that: (1) Portal Hypertensive Gastropathy (PHG) is a frequent
and significant cause of Occult Gastrointestinal Bleeding (OGIB) in patients
with cirrhosis, and (2) OGIB develops frequently in patients with PHG.
Our aims are: (1) To determine if PHG is a significant cause of OGIB in patients
with cirrhosis, (2) To determine the frequency of PHG in patients with OGIB
and cirrhosis, (3) To determine the incidence of OGIB in patients with PHG and
cirrhosis, (4) To quantify gastrointestinal (GI) blood loss in patients with
cirrhosis using Hemoquant assay.
Background
Occult GastrointestinaI Bleeding (OGIB) represents unrecognized blood loss
from the GI tract without overt signs of bleeding (hematemesis, melena or hematochezia).
It can be identified by a + fecal occult blood test (FOBT) or iron deficiency
anemia (IDA) if it has occurred for a longer period of time. Portal Hypertensive
Gastropathy (PHG) represents changes in the gastric mucosa as a consequence
of portal hypertension. PHG has many endoscopic appearances depending on the
degree of severity, but it is classically recognized as a mosaic like pattern
in the gastric mucosa. PHG is a common finding in patients with cirrhosis and
portal hypertension and has prevalence reported to be as high as 97% in some
series. Natural history studies suggest that PHG may cause acute and/or chronic
GI bleeding in patients with cirrhosis. Such studies report that the incidence
of chronic GI bleeding ranges from 6 to 20% in patients with PHG. In most studies,
the definition of chronic GI bleeding has been based on a decrease in hemoglobin
of 2 g/dL or more in 6 months without evidence of significant overt GI bleeding.
To this point, there have been no studies that have specifically focused on
OGIB, although it appears to be a relatively common finding in patients with
cirrhosis. In addition the design of previous studies did not allow proving
that PHG was a significant cause of chronic GI bleeding.
Therefore, in this study, we would like to determine if PHG is a significant
cause of OGIB in patients with cirrhosis. In addition we would like to quantify
prospectively the amount of blood loss from PHG by measuring the amount of hemoglobin
in stools by the heme-porphyrin test, Hemoquant.
We hypothesize that PHG leads to significant amounts of OGIB and therefore IDA
in patients with cirrhosis.
Concise summary of project:
This study is an observational cross-sectional study. Patients with liver
cirrhosis who meet inclusion criteria (see below) will be asked to participate
in the study. Once subjects agree proper written informed consent and HIPPA
forms will be signed. Patients will undergo the following procedures:
- Blood drawn for hemoglobin and serum ferritin. Blood drawn can be done at
the moment of evaluation in Gastrointestinal laboratory (GI lab), liver clinic
or COPC clinic.
- Previously scheduled upper endoscopy and/or colonoscopy as part of their standard
medical care.
- Formal stool testing using hemoccult and hemoquant will be performed. Patients
will be asked to collect stool samples and to bring it back to the investigator.
These procedures will be perform only one time. No follow up will be needed
as party of this study. Follow up will be done as part of the standard of medical
care.
After all these procedures, we will separate patients into 4 different groups
for further statistical analysis:
- Group 1: patients with OGIB and PHG
- Group 2: patients with OGIB without PHG
- Group 3: patients without OGIB and with PHG
- Group 4: patients without OGIB and without PHG
We anticipate that the identification of these groups of participants will be
beneficial for future studies.
Emily Harris Adhikari
Texas Tech
Mentor: Ronald Victor, MD
Division of Hypertension
A Barber-Based Intervention for Hypertension in African American Men
Background: It is well understood that African American men suffer disproportionately from hypertension (HTN) and its complications, and have lower rates of HTN control than all other racial/ethnic groups in the United States.
Project: We are in the final stages of completing a novel, community-based
intervention program targeting African American men with HTN who patronize barbershops
in Dallas County, Texas. This group-randomized trial involving 16 African American-owned
barbershops will test whether a continuous HTN detection and medical referral
program conducted by influential peers (barbers) in a receptive community setting
(barbershops) can promote treatment-seeking behavior and thus lower blood pressure
(BP) among the regular customers with HTN. In the intervention arm of the trial
(n=8 shops), 41 barbers were trained, equipped, and paid to incorporate a blood
pressure measurement into their daily work routine and offer a BP check with
every haircut, interpret the BP, complete a written encounter form, and discuss
role model stories-real stories of other male customers modeling the desired
changes in health behavior. This barber-based intervention draws on social-cognitive
behavior theory, emphasizing the role of influential peers (the barbers) in
promoting behavior change in others- in this case, the adoption of health-care
seeking behavior by the customer.
The current barbershop trial will be complete on November 15, 2008. Using data
from this trial, I will analyze individual barber productivity levels (measured
as the proportion of encounter forms completed to overall shop business) to
understand the substantial variability in barber productivity during the intervention
period. We believe that barbers can exert enormous influence on their customers'
healthcare-seeking attitudes and behaviors-if only they will try. Therefore
I will be exploring two critical questions during this fellowship year. First,
why did some barbers participate fully in the program and others did not? Second,
how do we fully engage a higher percentage of the barbers to enthusiastically
participate in future interventions?
To answer these questions, I am developing a survey instrument for all 41 barbers,
to be loaded on a laptop, validated, and pilot-tested in a separate barbershop
at the end of this year. The survey is constructed around 4 potential perceptual
factors that could have influenced whether or not a barber offered a BP check
with each haircut (the primary outcome of this study): (1) financial and health
risks and benefits, (2) social norms established in the barbershop, (3) self-efficacy,
and (4) social support by colleagues and customers. I will help survey the barbers
in each of the 8 intervention shops in early 2009, after which the survey data
will be linked to the main database from the barbershop trial and analyzed to
determine the significant factors influencing barber behavior. The long-term
goal of this project is to make the barbershop intervention program more attractive
to the next group of barbers, so that eventually, thousands of African American-owned
barbershops across the country might be transformed into hypertension detection,
referral, and follow-up centers.
Jaime Legendre
University of Miami Leonard M. Miller School of Medicine
Mentor: Ildiko Lingvay, MD, MPH
Division of Endocrinology
Project 1: Role of Pancreatic Triglycerides in Beta Cell Function
Diabetes is a growing problem in the United States with the increasing prevalence
of obesity. Type 2 Diabetes results from a combination of insulin resistance
and a relative defect in insulin secretion, or beta-cell function. In fact,
many patients with long standing type 2 diabetes will eventually lose all beta-cell
function and require insulin replacement. Our hypothesis is that triglyceride
accumulation in the pancreas leads to the defect in insulin secretion seen in
diabetics and those with impaired fasting glucose or impaired glucose tolerance.
We are investigated this hypothesis in a cross sectional study of volunteers
with normal glucose tolerance, impaired glucose tolerance or impaired fasting
glucose, and diabetes. We are performing a 75g Oral Glucose Tolerance Test to
determine glycemic status of each volunteer. We then perform a Frequently Sampled
Intravenous Glucose Tolerance Test which is used to quantitate the patient's
insulin production, insulin sensitivity, and the disposition index, a measure
of the patient's ability to produce enough insulin relative to their needs (i.e.
due to insulin resisitance). The final step to the study is Magnetic Resonance
Spectroscopy to quantitate the fat to water ratio (a measure of fat content)
within a sample of pancreatic tissue.
Project 2: Changes in Ectopic Fat Content After Bariatric Surgery: Does it
Explain the Resolution of Diabetes?
Often after bariatric surgery, weight loss results in the resolution of many
"complications" of morbid obesity, including hypertension, hypercholesterolemia
and diabetes. We hypothesize that the resolution of impaired glucose tolerance
or diabetes after bariatric surgery is due to a decrease in the pancreatic fat
content.
We are investigating this hypothesis in a longitudinal study of patients undergoing
gastic banding. We will perform a basline 75g Oral Glucose Tolerance Test to
determine glycemic status, a Frequently Sampled Intravenous Glucose Tolerance
Test to determine beta-cell function and Magnetic Resonance Specroscopy to determine
pancreatic fat content. We wil then follow the patients for 14 months after
gastric banding. We will perform the same tests to determine if there is a change
in beta cell function and if it correlates with a decrease in pancreatic fat
content, as measured by Magnetic Resonance Spectroscopy.
Christopher Malone
Tulane Unbiversity Medical School
Mentor: Fiemu Nwariaku
Department of Surgery
Project 1:
Epidemiological studies have shown a disproportionately high incidence of follicular
and papillary thyroid carcinoma among pre-menopausal women, suggesting that
circulating estrogen may be oncogenic for follicular thyroid cells. In-vitro
studies also show a mitogenic effect of estrogen on both papillary and follicular
carcinoma human cell lines. However, the specific genomic and non-genomic mechanisms
of estrogen-induced mitogenesis are unclear. Here, we propose using genome-wide
expression microarrays to examine the genomic effects of estrogen on human thyroid
cancer cell lines. In addition, we propose to examine the effect of estrogen
on normal human thyrocyte proliferation and genomic expression from primary
culture. By identifying estrogen-induced expression patterns, we can better
elucidate the mechanism estrogen may play into the carcinogenesis of papillary
and follicular thyroid cancer and may provide insight into novel therapeutics
and risk stratification.
Project 2:
Medullary thyroid carcinoma (MTC) is a malignancy of the thyroid C cells that
has been shown to be driven by numerous different mutations in the RET proto-oncogene.
Currently, there are no adjuvant systemic therapies. We propose to establish
a model of sporadic MTC using specific RET mutations in zebrafish (Danio rerio).
This is a high output model that can be used to for drug screens of various
anti-tumor agents. We hope that these drug screens can identify novel therapeutics
for various RET mutation-specific forms of MTC that can be proposed for use
in human clinical trials.
Christopher McPhaul
UT Southwestern
Mentor: Helen Hobbs, M.D.
Department of Molecular Genetics
The Genetics of Hepatic Steatosis
Non-alcoholic Fatty Liver disease (NAFLD) represents the pathological accumulation
of fat in hepatocytes. Development of this disease is related to insulin resistance
and obesity; however, it is also seen in 5% of the general population. In addition,
an ethnic disparity in the prevalence of NAFLD has been observed. Recent genetic
studies from the Dallas Heart Study led to the discovery a sequence variation
in PNPLA3 (I148M) that is associated with an increase in hepatic triglyceride
content in Hispanics and a decrease in hepatic fat in African Americans, which
are the groups with the highest and lowest prevalence of NAFLD, respectively.
PNPLA3, also known as adiponutrin, is a member of the patatin-like phospholipase
family; however, little is know about the substrate specificity or the function
of PNPLA3. My focus is directed at determining the subcellular location of the
protein and how the protein is regulated in response to metabolic perturbations
in an effort to understand the role of PNPLA3 in hepatic lipid metabolism and
in the development of NAFLD.
Akhil Narang
University of Illinois
Mentor: Abhimanyu Garg
Division of Endocrinology
Heterogeneity of adipose tissue gene expression.
The study of adipose tissue is of keen interest in the scientific community. While much is known about the effects of excess adipose tissue (obesity), less is understood about its depletion. Lipodystrophy is a rare disorder marked by focal or complete loss of adipose tissue. Studying patients with lipodystrophy has provided unique insights into adipose tissue biology. One variety of lipodystrophy, congenital generalized lipodystrophy (CGL) is an autosomal recessive disorder often characterized by hepatosplenomegaly, acanthosis nigricans, acromegaloid features, prominent umbilicus, hyperinsulinemia, and dyslipidemia (hypertryglyceridemia and low HDL). Female patients also exhibit enlarged clitoris, hirsutism, absent menstrual periods or oligomenorrhea, and occasionally polycystic ovaries. Cirrhosis or pancreatitis are not uncommon complications seen in CGLpatients.
Examination of CGL patients have revealed two distinct types. CGL2 patients have a greater absence of body fat compared to CGL1 patients. CGL1 patients have preserved mechanical fat depots (fat that plays a structural or protective roles, such as in the palms, soles, orbit, scalp, and periarticular) while near complete absence of metabolic fat depots (fat that plays an endocrine role, such as visceral fat). CGL2 patients display lack of both mechanical and metabolic fat depots. Genetic analysis reveals CGL1 is caused by mutations in the AGPAT2 gene and CGL2 results from alterations in the BSCL2 gene.
The distinct pattern of fat collections seen in CGL1 and CGL2 patients suggests the potential heterogeneous nature of adipose tissue. Variability in adipose tissue has not been well characterized. Differential gene expression levels between mechanical and metabolic fat may result in changes in adipose tissue differentiation.
Adipose tissue collected from the knee (periarticular) and subcutaneously were analyzed for global gene expression using microchip technology. Three genes (two of which are hypothetical) were identified to have a significant difference in expression levels between the two types of adipose tissue. The effect of these three genes on adipocyte differentiation is unknown. Through overexpression in 3T3-L1 cells (a well established model for adipogenesis), we will investigate the role of these genes in adipocyte differentiation. Specific molecular signatures of adipogenesis and intracellular triglyceride quantification will be used to confirm results obtained by cell-staining techniques.
Heidi Prather
UT Southwestern
Mentor: Nancy Olsen, MD
Division of Rheumatology
Heidi Prather is working with Dr. Nancy Olsen in the Department of Rheumatology on antibody profiling of systemic lupus erythematosus (SLE). Dr. Olsen has dedicated her research profession to improving the understanding of autoimmune diseases, including SLE. Many studies have been conducted that look at the cross-sectional antibody profiles of autoimmune diseases. In the Dallas Regional Autoimmune Disease Registry (DRADR), study subjects have been followed over time. Patients include systemic lupus (satisfied by ACR's >4 criteria), incomplete lupus (defined as <4 of the ACR criteria), first degree relatives of SLE, ANA (-) healthy controls, and ANA (+) healthy controls. Gene expression data and protein microarray data will be collected and reviewed for longitudinal changes. Medications, environmental exposures (smoking), disease course, and SLE risk factors will be taken into consideration while investigating the research question, "Do antibody profiles and protein arrays serve as markers of autoimmune disease?" The specific hypothesis being tested is that there exists a protective antibody profile that maintains tolerance of the immune system when breached, due to genetic or environmental stimuli, which allows the insurgence of disease-related antibodies in conjunction with a parallel reduction in the "protective" antibodies. With the addition of gene expression data to correlate with the antibody and protein microarray trends, we hope to find a 'signature pattern' that correlates with known lupus-related disease pathways. Monitoring "at-risk" individuals for reductions in protective antibodies and increases in disease-related antibodies may allow proactive treatment and prevention of life-threatening lupus-related events - which today are sometimes the first, and last, indications of autoimmune disease.
Lucas Rifkin
University of Kentucky
Mentor: Spencer Brown, PhD
Department of Plastic Surgery
Fluorescence-Activated Cell Sorting of Freshly-Isolated Human
Adipose-Derived Stem Cells: Identifying and Evaluating Subpopulations Based
on Surface Molecules
Adipose tissue, once perceived to be simply an energy reserve, is now recognized as a complex organ with an array of immunomodulatory, metabolic, and endocrine functions. Multipotent adipose-derived stem cells, capable of differentiating into adipose, cartilage, bone, muscle, and nerve, are easily obtained through routine plastic surgery procedures. These cells do not carry the burden of the ethical obstacles associated with embryonic stem cells, and treatments derived from adipose tissue hold great promise in the future of regenerative medicine. Although surface markers of adipose-derived stem cells have been described, there has been little examination of the properties of freshly isolated cells based on differences in surface protein expression. Our study will sort human adipose-derived stem cells based on proteins that may be either present or absent on the surface of these cells, then culture the resultant subgroups side by side to compare a number of characteristics.
We obtain adipose-derived stem cells from fat which is discarded following elective plastic surgery procedures such as liposuction and abdominoplasty. Adipose tissue is then digested in a collagenase-containing medium under agitation. Next, it is passed through a filter and centrifuged to obtain a cell pellet. The cell pellet is resuspended in an erythrocyte lysis buffer to remove red blood cells, and the suspension is centrifuged again. The remaining cells are stained with fluorescent-labeled antibodies specific for various surface molecules. Using a fluorescence-activated cell sorting machine, these cells are separated into tubes based on surface protein expression. Cells are then plated and cultured under a variety of conditions. Parameters being analyzed include proliferation capacity as well as adipogenic, chondrogenic, and osteogenic differentiation potential. Additionally, we will evaluate the influence of patient harvest site, age, gender, ethnicity, and BMI on cell yield and culture characteristics.
2007-2008 Fellows of the University of Texas
Southwestern Doris Duke
Clinical Research Fellowship Program for Medical Students
(UT Southwestern-Doris Duke-CRF)
Aditya Bagrodia
University of Tennessee Health Science Center
Mentors: Margaret Pearle, Jeffrey Cadeddu
Urology
Project 1: Impact of BMI on Cost and Clinical Outcomes following Percutaneous Nephrolithotomy, Mentor: Margaret Pearle, MD, PhD
Urolithiasis is a major health issue in the United States with a prevalence
of 12% in men and 6% in women. Kidney stone disease also carries a significant
financial burden. Total annual expenditures in 2000 were estimated at $2.1 billion,
including $971 million spent on inpatient services. Obesity is an expensive,
pandemic health concern affecting more than 30% of Americans. It is a known
risk factor for many systemic diseases including diabetes mellitus, gout, and
coronary artery disease. In addition, there is clear data suggesting obesity
is an independent risk factor for developing kidney stones.
The AUA best practice guidelines recommend ESWL and PCNL for large and staghorn
stones, with PCNL showing better stone-free rates for renal stones > 30mm.
ESWL is attractive due to low short-term complication rates and its non-invasive
nature. However, in high volume centers with experienced surgeons PCNL demonstrates
excellent stone free rates and low morbidity. Concerning obese patients, ESWL
is problematic due to limitations in targeting the stone by ultrasound or fluoroscopic
imaging and by the increased skin to stone distance. Many studies show that
BMI has an impact on surgical outcomes. Interestingly, however, this statement
does not seem to apply to PCNL, as several series demonstrate that obesity does
not influence outcomes following this operation.
With health care expenditures reaching record levels, medical practice is increasingly
affected by economic concerns. While previous work has shown favorable outcomes
in obese patients undergoing PCNL, there are no studies specifically addressing
the impact of obesity on costs of PCNL. In this study, we present a contemporary
series of PCNL and determine how obesity impacts both clinical outcomes and
associated costs.
Project 2: Development of Single Access Keyhole Nephrectomy and comparison to traditional laparoscopy, Mentor: Jeffrey Cadeddu, MD
Laparoscopic nephrectomy has assumed a more central role in the management
of benign and malignant kidney diseases. Advantages of laparoscopic nephrectomy
in comparison to open surgery are well established. Retrieval of laparoscopic
nephrectomy specimens typically requires extension of an existing incision or
creation of an additional incision. As such, at the conclusion of the surgical
procedure, patients generally have three or four incisions each extending 1-4cm
in length. In an effort to reduce the morbidity and improve the cosmesis of
laparoscopy, Gill and colleagues have described their success with transvaginal
extraction of nephrectomy specimens.
Natural orifice translumental endoscopic surgery (NOTES) is an extension of
this concept by approaching abdominal surgery through natural orifices, thus
obviating external scars. In 2002, Gettman and colleagues described their experience
with transvaginal laparoscopic nephrectomy in a porcine model using standard
instrumentation. More recently, Clayman et al. presented their experience with
single-port NOTES nephrectomy with purpose-built equipment.
An alternative to NOTES is single access surgery utilizing flexible laparoscopic
instruments. Such instrumentation would obviate the need for triangulation of
trocars allowing for the creation of a solitary portal of entry into the abdomen.
We intend to evaluate our initial experience of single keyhole umbilical nephrectomy
and compare this new technique to traditional laparoscopy.
Rachael Cayce
UT Southwestern
Mentor: Heidi Jacobe
Dermatology
Autoantibody and Human Leukocyte Antigen (HLA)locus profiling in adult and children
with Morphea
Morphea is frequently classified as the skin only manifestation of scleroderma.
The current classification system of morphea divides it into five categories
based solely on cutaneous clinical findings without reference to other considerations
such as associated systemic manifestations, concomitant or familial predisposition,
or autoantibody profile. This conception of morphea is based on little evidence,
and may even be false. This negatively impacts patient care. A number of studies
report an increased prevalence of autoantibodies, concomitant autoimmune disorders,
and systemic findings in some subtypes of morphea patients. The usefulness of
these reports are limited due to sample size, lack of a control group, referral
bias and their observational nature.2-7 Thus, there are hints that morphea represents
a systemic autoimmune disease, but the nature of this association by subtype
is still undefined. In this study we will test for clinical associations of
morphea with serological autoantibody profiles and HLA allelotyping via an initial
case-control study.
The central hypothesis is that although morphea is thought to consist of one
disorder with only cutaneous manifestations, it is comprised of distinct syndromes
defined by subtype with characteristic clinical, serological, and genetic traits.
Specifically, generalized morphea and mixed (specifically the combination of
linear and plaque) morphea represent distinct entities with an increased risk
of familial and concomitant autoimmune disorders with corresponding distinct
immunological and genetic profiles.
Project Summary
This is a case-control study of adult and pediatric morphea patients (3 years
or greater) comparing the frequency of systemic manifestations, concomitant
autoimmune disorders and family history of autoimmune disorders in morphea against
age, sex, and race matched normal and scleroderma controls. We will also collect
baseline autoantibody profiles and HLA types to define those associated with
the disease and its subtypes. The demographic, clinical, and laboratory features
are being ascertained using validated instruments and state of the art technology.
Cases will be enrolled regionally from Texas, Oklahoma, and Arkansas, as well
as nationally with anticipated enrollment of 250 subjects regionally and 250
subjects nationally (total 500). Subjects enrolled regionally will be evaluated
at the University of Texas Southwestern Medical Center Department of Dermatology's
Clinical Research Office, while those enrolled nationally will send all completed
forms, medical release forms, and blood collections to the Department's Research
Office. These patients will be invited to enroll in a prospective cohort of
patients to be followed annually will repeat measurements of these values and
to assess what their significance is to the prognosis of these patients.
Shana Elman
Medical College of Wisconsin
Mentor: Marlyn Mayo
Liver and Digestive Diseases
TREATMENT OF CHRONIC PRURITUS
Background: Pruritus is a common and potentially disabling symptom. Current
treatments for pruritus are not consistently effective and thus, further treatment
modalities need to be explored. The subjective nature of pruritus makes its
quantification difficult; however testing of improved therapies for pruritus
requires a descriptive and quantitative measure that can evaluate the effects
of treatment over time. Current measures assess intensity, but do not adequately
assess other components, such as how often or where patients itch, sense of
improvement or worsening, and impact on quality of life. Also, current measures
have not been validated to assess changes in pruritus over time.
Project #1: A New Measurement of Pruritus
This research project aims to develop and validate a new scale, the 5-D Itch
Scale, that provides a descriptive measure of pruritus that can be applied to
any patient presenting with pruritus, and can be used as an outcome measure
in clinical trials of pruritus. The 5-D measures 5 domains of pruritus: duration,
degree, direction, disability, and distribution. The 5-D was administered to
patients complaining of pruritus related to liver disease, kidney disease, AIDS,
burn wounds, or other primary skin disease at enrollment, 3-days, and 6-weeks
later. We are currently analyzing the data to assess construct validity, internal
consistency, test-retest reliability, responsiveness, acceptability, and precision
of the 5-D.
Project #2: A Study of INT-747 (6-ECDCA) in Combination with Ursodeoxycholic
Acid in Patients with Primary Biliary Cirrhosis
Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease characterized
by inflammation, progressive destruction of the hepatic bile ducts and fibrosis.
Typically, patients present with pruritus and fatigue. The only FDA-approved
drug therapy for cholestasis, specifically for PBC, is the bile acid ursodeoxycholic
acid (UDCA). Although UDCA provides sustained therapeutic effects in a subset
of patients with PBC whose serum liver biochemistry values normalize over time,
the majority of patients experience an incomplete response with continued disease
progression and UDCA appears to do little to improve the main symptoms of PBC,
pruritus, and fatigue. The farnesoid X receptor (FXR) is involved in the bile
acid regulatory pathway, and therefore has been suggested as a potential target
for new treatments for PBC. This research study aims to assess the safety and
efficacy of a new FXR agonist , INT-747, as an adjunct to UCDA in the treatment
of PBC. Multiple outcome measures will be used to determine efficacy and safety
of this novel therapy, including the new 5-D Itch Scale that we have developed
to assess improvement in pruritus.
MECHANISMS FOR PROMOTING RESEARCH CAREERS IN MEDICAL STUDENTS
Background: Advances in biomedical research have occurred at unprecedented rates
over recent years providing a ballooning of opportunities for translational
and clinical research. However, the supply of physician-scientists has not been
able to keep up with this demand. Organizational and cultural barriers within
the practice of medicine (e.g. economic pressures on the healthcare system,
increased clinical responsibilities for academic faculty, etc.) have been cited
as reasons for this steady decline in physician-scientists. In addition, the
age of funded NIH investigators has continued to rise since the mid-1980s, suggesting
that early intervention is necessary to encourage young physicians to explore
careers in research and to provide them with the necessary skills to become
successful young investigators.
Project #1: Effect of Medical Student Research Programs on Interest in Research
Careers
Several strategies are currently used to expose medical students to research
(e.g. summer research opportunities, "year-out" programs, MD-PhD programs);
however little research has been done to compare the effectiveness of these
methods in increasing medical student interest in research careers. The present
study will compare the change in level of interest in research as a career activity
at the beginning and end of medical school for UT Southwestern medical students
completing summer research projects, students taking a year off to conduct research
("year-out" program participants), and students completing the MD-PhD
program. Each group will also be compared to UT Southwestern students who do
not participate in one of these research programs. In addition, student characteristics,
such as demographic variables, will be assessed to determine whether certain
students benefit from particular types of research activities. The results of
this study should provide much needed insight into the effects of three of the
most common medical student research experiences.
Charu Gupta
UT Southwestern
Mentor: Mark Drazner
Cardiology
Disease Background: Heart Failure
Heart Failure is a growing epidemic in the United States. The American Heart
Association estimates that of people forty and older, one in five individuals
has a risk of developing heart failure in his lifetime. Estimates of incidence
are 550,000 individuals, with a total of 5 million affected nationwide. Currently,
10% of individuals die within one year of heart failure diagnosis and 50% die
within 5 years of diagnosis. Though multiple pharmacologic therapies are used
in combination for the treatment of congestive heart failure, increased ability
to sense changes in patients' health status rests on monitoring subtle subjective
symptoms and evaluating new modes of diagnosis and treatment. In the following
year, multiple projects are proposed - all focused around the problem of heart
failure.
Project #1: Phono-electrocardiography in Heart Failure: evaluation of a new
technology that detects diastolic heart sounds in patients and defines alternate
parameters of heart functioning. A new technology promises information that
can be used to more quickly diagnose new-onset heart failure, to detect an acute
heart failure decompensation, or to increase pacer efficiency through cardiac
resynchronization. We intend to evaluate the reliability and validity of machine
readings and correlate with clinical information to assess prognostic value
over time.
Project #2: Consideration of "Bendopnea" as a new heart failure symptom:
the prevalence and hemodynamic implications of shortness of breath in varying
positions. Stevenson and Perloff's research from 1989 showed that the combination
of rales, edema, and elevated JVP had a 58% sensitivity and 100% specificity
for PCWP greater than or equal to 22. This study recognized the tendency of
physicians to use physical signs as markers of disease severity; however, this
demonstrates that the current signs and symptoms provide an incomplete assessment
of a patient's status. We intend to define a novel symptom in HF and investigate
its physiological basis.
Project #3: Implications of Public Opinion on Organ Donation: Louise King,
a Doris Duke Research Fellow, described the ethical paradox of uninsured donors
(25% of organ donors) contributing to the donor pool despite the limitation
of organ recipients to individuals with insurance (Journal of the American College
of Cardiology, May 2005). The authors hypothesized that this unequal allocation
of resources may contribute to public unwillingness to donate organs and distrust
of the medical community. We intend to investigate whether the public recognizes
this unequal distribution of resources, and whether this impacts the willingness
of the public to donate organs.
Anshu Jain
University of Kentucky College of Medicine
Mentors: Hak Choy, David Chen, Chaitanya Nirodi
Radiation Oncology
Project 1: Radioresistance and EGFR Therapeutics in Non-Small Cell Lung Cancer
Non-small cell lung cancer, especially in its late stages, presents a significant treatment challenge to the clinician. Recently, there has been much interest in novel therapeutics like cetuximab, geftinib, and erlotinib. These drugs exert their effects by acting on plasma membrane EGFR. Recently, it has been shown that EGFR plays a role in the repair of double stranded DNA breaks induced by ionizing radiation. This introduces an important role for these drugs as potential radiosensitizers in combined modality treatment of NSCLC. Our work aims to: A) Characterize the role of EGFR in DNA repair induced by ionizing radiation, and assess the radiosensitizing effects of these novel chemotherapeutic agents, and B) further characterize the exact interactions of EGFR in the context of DNA repair to identify a potential target for future therapeutics.
Project 2: Novel Chemoradiation Regimens for the Treatment of Advanced Stage Non Small Cell Lung Cancer
There are no clearly superior treatment options for later stage NSCLC, especially inoperable cases. We seek to identify new combined modality regimens of chemotherapy and radiation for the treatment of Stage III onward NSCLC. We begin our investigations through a number of Phase I trials designed to assess the toxicity of novel regimens and phase II trials to assess potential efficacy. Regimens involve using newer chemotherapies including Taxol, Taxotere, and newer platinum agents in combination with varying methods of radiation administration.
Dhruti Patel
Northeastern Ohio Universities College
Mentors: Abhimanyu Garg
Center for Human Nutrition
Title: Mechanisms of lipodystrophy in highly active antiretroviral therapy in HIV infected patients.
Background: In the developed world, HIV has become a chronic rather than a fatal diagnosis. However, the treatment does come at a risk of metabolic derangement. One such change is a lipodystrophy syndrome which includes progressive loss of subcutaneous fat from the arms, legs and face with excess fat in the dorsocervical, neck and trunk regions. The precise underlying mechanisms related to HAART-induced lipodystrophy are currently unknown although some progress has been made. Dr. Garg and his colleagues have completed a 2 year randomized, double-blind, placebo-controlled, prospective trial of newly diagnosed HIV infected patients on either Efavirenz (a non-nucleoside reverse transcriptase inhibitor)-based or nelfinavir (a protease inhibitor)-based highly active anti-retroviral therapy (HAART).
Project: In an attempt to elucidate these criteria, analysis of body fat changes
from anthropometry, dual energy X-ray absorptiometry and magnetic resonance
imaging (MRI) performed annually for each patient will be completed. The hypothesis
is that PI-therapy is associated with loss of subcutaneous fat in the extremities.
Secondary hypothesis is that PI therapy is associated with accumulation of fat
in the trunk, neck and dorsocervical regions of the body. We will also test
the hypothesis that changes in adipokines such as, adiponectin, leptin, retinol
binding protein 4 and visfatin, will correlate with the changes in body fat
distribution. We will measure these adipocytokines in stored plasma and correlate
these with changes in body fat distribution.
Teddy Youn
Brown University School of Medicine
Mentors: Ramon Diaz-Arrastia, Christopher Madden
Neruology, Neurosurgery
Diffusion Weighted Imaging and Biological Fluid Biomarkers in Acute Traumatic Brain Injury
Diffuse Axonal Injury (DAI) results from high velocity deceleration and shear strain, and is believed to be the predominant mechanism of injury in 40 - 50% of TBIs requiring hospital admission in the US. DAI is poorly imaged by CT scanning, and conventional MRI, the current method of choice, has not been carefully studied and is of uncertain sensitivity and specificity. The inability to accurately identify and measure DAI during life is a major limitation in the clinical management of TBI. Additionally, clinical trials of neuro-protective and axono-protective therapies directed at DAI are unlikely to be successful unless there are reliable and validated biomarkers which will allow subphenotyping of injury mechanisms, including DAI. The goal of our proposal is to develop and validate Diffusion Weighted Imaging (DWI) as a biomarker of DAI. The anatomy and integrity of white matter fiber tracts can be determined noninvasively with DWI, providing new information about brain networks. Preliminary data from our group indicates that Diffusion Tension Imaging (DTI), a variant of DWI, is more sensitive than conventional structural MRI for identifying DAI lesions. A secondary objective is to determine if certain biological fluid biomarkers (S-100B protein, Tau protein, and Myelin Basic Protein [MBP] can be effective biomarkers when used in conjunction with neuroimaging modalities like DWI. We will accomplish our objectives through the following specific aims:
(1). Obtain MRI scans on patients with DAI in the acute period (within 24 hours after injury). Patients enrolled will have suffered moderate and severe closed head injuries during high-velocity motor vehicle collisions. Patients requiring craniotomies as well as those with significant midline shift will be excluded. We plan to enroll 15 patients in the study over a 7-month period. Patients will be scanned at 3T and DWI as well as DTI performed in 18 - 30 directions. Additional image measures will include high resolution T1 weighted, FLAIR images, and susceptibility weighted imaging. An additional 15 controls matched by age and gender to the patients will also be recruited and scanned.
(2). Obtain repeat MRI scans 10 - 14 days later and repeat MRI scans and outcome information 6-months after injury. Patients who survive the acute period will be asked to return for a repeat MRI 6 months after injury. Additionally, outcome will be assessed using a focused neuropsychological battery and validated structured interviews. We anticipate a 10% acute death rate and a 15% loss to FU rate, thus we anticipate obtaining 12 - 13 follow-up scans.
Role of the Doris Duke Fellow:
The fellow will be primarily involved in identifying eligible patients, prospectively collecting clinical information relating to the severity of the initial traumatic injury, following the patients and collecting biological fluid biomarkers daily for the first five days during their acute hospitalization as well as obtaining outcome data at 6 months post-injury. These tasks will be accomplished by having the fellow attend daily morning rounds with the neurosurgical service at Parkland Memorial Hospital, identifying patients who meet eligibility criteria for the study, obtaining informed consent from patients or family members, and collecting intake information. Afternoons will be spent obtaining outcome information via telephone interviews and analyzing MRI data using the programs MRICro, DTI Studio and Freesurfer.
2006-2007 Fellows of the University of Texas
Southwestern Doris Duke
Clinical Research Fellowship Program for Medical Students
(UT Southwestern-Doris Duke-CRF)
John Anderson
UT Southwestern
Mentors: Robert Timmerman
Hak Choy
Radiation Oncology
Stereotactic Radiotherapy of Brain and Paraspinal Metastases
Background:
Cone Beam Computed Tomography (CBCT) is an imaging technique that is employed
for accurately targeting tumors for radiotherapy by quantifying changes in patient
anatomy from the treatment plan immediately prior to treatment. There are a
number of imaging methods that are currently in use for this purpose, but the
advantage of CBCT is its capability to image soft tissue, especially neoplastic
tissue, on the treatment table. Presently, CBCT is only utilized to determine
the degree of displacement of anatomical and/or implanted markers from an initial
planning CT scan obtained on a conventional CT scanner. By also utilizing the
CBCT scanner to obtain the initial image for treatment planning, it may be possible
to set up the patient at the treatment table and generate a plan without moving
the patient.
Project Description:
We are investigating the feasibility of utilizing CBCT images for treatment
planning for extracranial external beam radiotherapy. A process for obtaining
CBCT images and planning treatments with the patient remaining on the treatment
table will be developed. Studies utilizing anthropomorphic phantoms will be
performed, evaluating the timing of individual steps. Plans and dose distributions
generated from CBCT images of the phantoms and patients will then be compared
to helical CT images to determine the accuracy of the treatments plans. Time
permitting, we intend to also investigate CBCT images for treatment planning
in cranial sites.
Sarah Davis
UT Southwestern
Mentor: Susan Iannaccone
Pediatric Neurology
Quality of Life Validity Testing of the Neuromuscular Module in Duchenne Musucular Dystrophy
Disease Background
Duchenne muscular dystrophy (DMD) is the most common genetic neuromuscular disorder,
affecting 1:3500 live male births. It is an X-linked recessive disease that
manifests as progressive proximal weakness due to an insufficient quantity and
quality of the protein dystrophin. A defect or deficiency in this large protein
located near the sarcolemmal membrane leads to cell breakdown in muscle cells.
Diagnosis typically occurs around 3-5 years of age with mild weakness that progresses
over the course of several years to the point of loss of ambulation and need
for respiratory assistance. Multiple organs are affected, potentially resulting
in cardiomyopathy, restrictive lung disease, mental retardation, and osteoporosis.
Death typically occurs when the patient is in his twenties due to aspiration,
respiratory infection, or heart failure. Treatment is limited to corticosteroids
that slow the progression of muscle weakness but incur other side effects such
as weight gain. Symptomatic treatment for disease-associated processes are also
used as indicated, such as enalapril for heart complications and positive pressure
ventilation for sleep apnea. There is currently no cure for this disease.
Patient Population
DMD patients seen in the pediatric neuromuscular clinic undergo a full evaluation,
including assessment by a physician, functional testing and recommendations
by physical and occupational therapists, pulmonary function tests, and referrals
as needed to pediatric cardiology and pulmonology subspecialists. Patients and
parents also are requested to complete two quality of life (QOL) surveys: the
generic and neuromuscular pediatric modules. The generic form addresses issues
faced by the child such as his general health, emotions, relationships with
peers, and school. The neuromuscular module assesses more disease-related facets
of the patient's well-being including activities of daily living (ADLs), ability
to communicate about his disease, and the status of the family unit as affected
by the pressure of the disease. This survey has been implemented for several
years in the child neuromuscular clinic but has yet to be validated.
Project Summary
Both the parent(s) and the child will complete both a general pediatric QOL
survey as well as the pediatric neuromuscular survey. The modules are to be
administered by the research fellow to ensure consistency between patient encounters.
This baseline assessment will then be compared to a second administration of
the same surveys six weeks later. The two sets of responses for the individual
will then be compared. In addition, this subjective data will be compared to
objective measurements of functioning specific to the disease such as ambulatory
status, activity level, ventricular ejection fraction, and forced vital capacity.
Christopher De Renzo
Robert Wood Johnson Medical School
Mentor: John Minna
Hematology/ Oncology
Lung cancer is common widespread and deadly. It is the number one cancer killer
in the United States and worldwide. With expected 5 year survival rates for
all patients with the disease being about 15 %, new insights into lung cancer
pathogenesis and progression are welcome.
A relatively new focus, in the field of lung cancer research, is the role of
the microenvironment on development of the malignant lung cancer phenotype.
A microenvironment is defined by three parts: 1)stromal cells, such as fibroblasts,
endothelial cells and lymphocytes 2)Insoluble extracellular matrix of collagen
and other proteins and 3) growth factors and cytokines. Our laboratory has used
in vitro 3-Dimensional models to study normal bronchial epithelial cells and
lung cancer cell within a manipulatable microenvironment. However, an obstacle
to practical use of such models has been a large time requirement to complete
such experiments, which led to contamination issues and difficulty in result
replication. The goal of my current project is to validate a procedure for creating
such 3-D models in a time efficient manner.
In our laboratory 3-Dimensional models of normal human bronchial epithelium
are constructed by first plating collagen and fibroblasts on a transwell plate.
The collagen and fibroblasts are incubated until they form a semisolid, contracted
gel. Bronchial epithelial cell lines are plated on top of the fibroblast-collagen
gel and incubated in growth media. After incubation, the cultures are fixed,
sent for histology, and observed by a trained clinical pathologist. The main
difference of the new method is incubation time has been decreased from 21 days
to 7 days. If the 7 day incubation method produces histological results similar
to the 21 day method, use of the model to study the lung microenvironment should
be more practical.
If the method is validated, I will manipulate the source of fibroblasts to see
if the microenvironment has an effect on epithelial cell invasion. For example,
past evidence from our lab shows that normal human bronchial epithelial cells
are more likely to invade through fibroblasts from a patient with lung cancer,
than they are to invade through fibroblasts from a patient without lung cancer.
However, results of this study were preliminary and have not been replicated.
If such results can be replicated, the next step would be to decipher genetic
differences between the fibroblast types that may lead to the invasive phenotype.
The overall aim of this project is to create a practical method for studying
lung epithelial cells within a manipulatable microenvironment. If this is successfully
accomplished the model will serve as a convenient method to test hypotheses
on the role of the microenvironment on lung cancer progression.
Shana Elman
Medical College of Wisconsin
Mentor: Marlyn Mayo
Internal Medicine/ Liver and Digestive Diseases
Pruritis in liver disease
Pruritus is a common and potentially distressing symptom. Itching affects quality
of life and when severe, can be disabling-interfering with daily activities,
resulting in significant skin irritation from scratching, leading to sleep deprivation,
and/or contributing to psychological disturbances. Current treatments for pruritus
are not consistently effective and thus, further treatment modalities need to
be explored.
The elusive pathophysiology of pruritus and the subjective nature of pruritus
further complicates the process of development and testing of new therapies.
Currently, few measures are available to assess itching. The visual analogue
scale (VAS) for pruritus is the most commonly used measure, which asks patients
to rank their degree of itching on a visual analog scale from 1 to 10 (1=no
itching, 10=intolerable itching). While this scale allows easy quantification
of itching, it does not provide much description of the distribution, duration,
direction, or disability of the itching. The VAS has also been criticized for
its weak ability to demonstrate changes over time. Recently, the PBC-40 was
developed, which is a questionnaire that assesses six domains (itch, fatigue,
emotional, social, and cognitive functioning, and general symptoms) of primary
biliary cirrhosis (PBC). The itch domain of the PBC-40 inquires about the impact
of itch on sleep, skin irritation, and psychological factors. However, the PBC-40
was developed and validated specifically for patients with PBC. This scale also
lacks validation for use in tracking changes in pruritis over time. Further
investigation of the pathophysiology of pruritus and evidence-based assessment
of potential therapies requires validated methodologies to be available for
description and quantification of symptoms in diseases other than PBC and a
validated method to assess changes in pruritus over time.
Project #1: A New Measurement of Pruritus
This research project aims to develop and validate a new scale that provides
a descriptive measure of pruritus that can be applied to any patient presenting
with pruritus, and can be used as an outcome measure in clinical trials of pruritus.
Itching can be related to many types of disease. This questionnaire will be
administered specifically to people who complain of itching related to liver
disease, kidney disease, AIDS, cancer, intrahepatic cholestasis of pregnancy,
or a primary skin disease. Subjects will be sent a follow-up questionnaire 6
weeks later to determine the questionnaire's ability to track changes in pruritus
over time.
Specifc Aims: 1) To develop a new measure of pruritus, the 5-D (Distribution,
Duration, Degree, Direction, and Disability) Descriptive Pruritus Measure. 2)
To compare the 5-D to current pruritus measures-the visual analog score and
the itch domain of the PBC-40. 3) To validate the 5-D in multiple patient populations,
specifically patients with liver disease, renal disease, AIDS, cancer, intrahepatic
cholestasis of pregnancy, and primary skin disorders. 4) To validate the ability
of the 5-D to track changes over time.
Project #2: Treatment of Metabolic Pruritus
Patients with liver disease taking sertraline were noted to have a decrease
in symptoms of pruritus. Serotonin receptors are located in both the sensory
nerve terminals and the dorsal horn and may be important in the regulation of
itch. Therefore, it is possible that selective serotonin reuptake inhibitors
(SSRIs), such as sertraline, may be useful as an anti-pruritic agent.
The purpose of this research is to determine the safety and efficacy sertraline
as an anti-pruritic agent in patients with liver disease and kidney disease.
Data has previously been collected on patients with liver disease. The current
focus of this project is to enroll patients with kidney disease. Patients will
receive 8 weeks of treatment with sertraline in a randomized, double-blind placebo-controlled,
cross-over design. Throughout the study patients will keep a daily diary to
track their pruritus. They will also be seen at weeks 2, 10, 14, and 22 weeks
for evaluation of their pruritus and for blood tests (CBC, chemistries, plasma
sertraline and desmethylsertraline levels).
Specific Aims: 1) To determine whether sertraline, as compared to placebo, improves
the symptom of pruritus in patients with liver or kidney disease. 2) To determine
the optimal dose and time to response of sertraline in the treatment of pruritus.
Allison Jordan
UT Southwestern
Mentor: Jodi Dashe
Ken Leveno
Obstetrics and Gynecology
Serotonin Reuptake Inhibitor Use During Pregnancy: Perinatal Outcomes
Purpose: This is a retrospective evaluation of pregnancy outcomes and
neonatal complications following maternal use of serotonin reuptake inhibitor
medications during pregnancy.
Background: Approximately 10% of pregnant women suffer from depression.1
Serotonin-reuptake inhibitors are the most commonly used antidepressants, and
because of their side-effect profile, these agents are the first-line treatment
in pregnancy. There has been increasing concern that maternal use of SRI's prior
to delivery can lead to a potentially-serious neonatal behavioral syndrome in
exposed neonates. The syndrome, also called neonatal withdrawal or poor neonatal
adaptation, is generally mild and self-limited, though it may require supportive
care in a special care nursery and increase hospital stay. Signs may include
one or more of the following: jitteriness or irritability, temperature instability,
hypoglycemia, poor tone or increased tone, respiratory distress, weak or absent
cry, or difficulty feeding2,3 Features of this syndrome have been compared those
of adults with either SRI discontinuation symptoms or SRI toxicity. 4
Recommendations regarding management of neonates exposed to SRI's in-utero,
vis-à-vis duration of observation, evaluation or testing for evidence
of behavioral maladaptation, or even treatment, are limited. Oberlander and
colleagues found that 25% of 28 neonates exposed to an SRI alone, and 39% of
18 neonates exposed to an SRI and benzodiazepine combination had symptoms reflecting
poor neonatal adaptation. 5 In all cases, findings resolved within 48 hours.
Using the Neonatal Abstinence Scoring system, 6 Levinson-Castiel and colleagues
recently reported that 30% of 60 exposed neonates had evidence of withdrawal;
however, no neonate was felt to require treatment with medication, and maximum
scores were recorded within 2 days after birth. 7
In addition to the neonatal behavioral syndrome, investigators have described
(1) a slight increase in congenital cardiac anomalies associated with paroxetine
use only 8; (2) a small increase in the neonatal risk of persistent pulmonary
hypertension 9; and (3) an increased risk preterm birth and fetal death. 10,11.
With the exception of preterm birth, the above outcomes have been reported to
occur in 1% or less of exposed pregnancies.8-11
Concise Summary of Project: The Parkland Obstetrical Psychiatry Complications
clinic is a multidisciplinary clinic providing care for pregnant women who require
initiation of psychiatric medication(s) or who have recently been hospitalized
for a psychiatric diagnosis and are in need of out-patient care. The clinic
sees approximately 150 women per year, and the majority of women seen (>
80%) receive treatment with serotonin reuptake inhibitor medications.
We propose to review the computerized appointment logs for this clinic to obtain
a list of women seen from September 2005 through August 2006. Using this list,
we will obtain data from 3 sources to evaluate the effects of SRI's on pregnancy
and neonatal outcomes: maternal medical records, neonatal medical records, and
our division's obstetrical database. Records will be reviewed only following
delivery and hospital discharge, to assure complete ascertainment of data. Women
who are seen in this clinic but who do not need SRI's will also be included
as a control group. Rates of selected pregnancy and neonatal complications in
these 2 groups will also be compared with complication rates for our overall
population, which we will evaluate using our division's obstetrical database.
Specific data collected and procedures to assure confidentiality are listed
below.
Our goals are to evaluate the prevalence of pregnancy complications and the
neonatal behavioral syndrome (and any other neonatal complications) according
to maternal medication and dosage. Other variables that might affect neonatal
adaptation, such as prematurity or low-birth weight, will also be evaluated.
We hope to provide physicians and their patients with a better understanding
of what to expect if these medications are needed during pregnancy, specifically
what type of care is needed, duration of hospitalization needed, and potential
sequelae.
Sources of research material: Data from 3 sources will be included: maternal medical records, neonatal medical records, and our division's obstetrical database. From the maternal medical records, variables extracted will include identifiers (name and medical record number and date of service), gestational age at enrollment for care, gestational age when seen in the Obstetrical Psychiatry Complications clinic, gestational age during which the patient took SRI's and any other medication, medication name(s) and dosage, whether the medication was adequately treating the problem, any substance abuse, and any medical or obstetrical complications. From the division's obstetrical database we will obtain a list of neonatal medical record numbers. Variables we will extract from the neonatal records will include: name and date of birth, any evidence of respiratory difficulty and the treatment required, any evidence of increased or decreased tone, irritability or jitteriness, feeding difficulties, hypoglycemia, temperature instability, or other complications. We will also use the electronic database to obtain the following outcomes: maternal demographic variables, pregnancy outcomes such as gestational age at delivery, indication for delivery, any delivery complications, birth weight, Apgar score, neonatal length of stay, need for special care nursery, and any obvious birth defects.
Potential benefits:
(1) To subjects: As this is a retrospective study, the subjects will not directly
benefit. The results of this study do have the potential to impact patient counseling
and care in the future. For this reason, it is possible that subjects may benefit
in future pregnancies.
(2) To society: Currently, there is limited information available regarding
perinatal complications associated with serotonin reuptake inhibitor (SRI) use.
Areas in which our study may provide clinically-useful information include:
severity of the neonatal behavioral syndrome in SRI-exposed infants, whether
it is affected by the specific SRI used, and effects of factors such as medication
dosage and gestational age at delivery. Information from this study may assist
health-care providers counseling patients and assist providers evaluating newborns-who
may use this information to make recommendations regarding level of care in
the hospital and length of stay.
Justin Leitenberger
University of Texas - Houston Health Science Center
Mentor: Heidi Jacobe
Paul Bergstresser
Dermatology
Project #1: Morphea database and initiation of observational studies looking at risk factors in the development of disease
Background
Morphea is a disorder characterized by thickening and hardening of the skin
and subcutaneous tissue due to excessive collagen deposition. Among the subtypes
of morphea is plaque-type, linear scleroderma, and generalized. The cause of
morphea is unknown but case reports suggest an environmental factor such as
trauma, irradiation, infections, vaccinations, or drugs as inciting factors
in the development of this disease.1-5 Case reports also reveal an association
with other autoimmune disorders.6-8 The literature describing morphea is limited
and epidemiologic data has not been confirmed with larger studies.9 A recent
study in a European population of children with juvenile localized scleroderma
described the basic relationship of environmental factors (13.3%) and family
history of autoimmune diseases (12%) as correlations with localized scleroderma.10
Linear scleroderma is more common in pediatric populations whereas plaque-type
morphea is more commonly found in adults. Currently, there is no one therapy
for localized scleroderma that has proven to be very effective or significantly
disease modifying.11 Broader studies regarding the diagnosis and etiology of
morphea may provide unique insights on treating this disease.
Research Questions:
1. Among patients with morphea, is there an inciting event which triggered the
disease?
2. What is the association, in patients with morphea, with other concomitant
autoimmune disorders?
Project #2: Outcome Measures in Dermatology - A review and call to action for improved clinical trials
Language and interpretation of clinical trial outcomes - surrogates, composites, scores, endpoints, etc.
-Definition of outcome measures
-Concept of surrogate endpoints as outcome measures - definitions, pitfalls,
and criteria for surrogates
-Different types of endpoints in Dermatology - Scores, Quality of Life measurements,
patient satisfaction, utilities, cost-effectiveness, technology based measures
-Interpreting outcome measures in clinical trials - designation of primary endpoints,
secondary endpoints, the problem of multiple primary endpoints, and statistical
significance
Christopher Maroules
Indiana University School of Medicine
Mentor: Ron Peshock
Internal Medicine / Radiology
Project 1: MRI characterization and perfusion using vasodilatory challenge in patients with cardiomyopathies at risk for sudden cardiac death.
The purpose of the study is to determine if cardiac magnetic resonance imaging done prior to the implantation of a cardio-defibrillator predicts future firing of the defibrillator for serious cardiac arrhythmias. Recent studies have shown a reduction in sudden death in patients with severe left ventricular dysfunction following treatment with an implantable cardio-defibrillator (ICD) (ref). However, the total event rate in populations at risk is relatively low (ref). In addition, these devices are extremely expensive ($20-30k/device) and it has recently been reported that implantation is associated with a 4% complication rate. Thus, it would be desirable to identify those patients at highest risk who would benefit most from this procedure. It is well established that the presence of focal fibrosis can play an important role in the generation of arrhythmias in patients but it is not known if this is a common feature which predicts the response to ICD implantation. There are now extensive data which indicate that magnetic resonance delayed enhancement imaging with gadolinium can identify areas of cardiac fibrosis due to both ischemic and non-ischemic heart disease. The study will involve 50 patients who are scheduled for implantation of an ICD for clinical indications. Before implantation, each participant will undergo imaging at 1.5 Tesla on a standard clinical system at UT Southwestern. All cardiac images will be obtained during a 12-15 heartbeat breath hold at end-expiration, averaging 10-15 seconds with adequate rest periods between breath holds. Following the acquistion of scout images, a series of short axis and long axis series will be obtained in each patient using a standard tissue tagging protocol for ejection fraction determination. Following MRI tissue tagging, patients will receive a bolus intravenous injection of gadolinium-DTPA. High-resolution delayed enhancement images will be obtained using a previously described inversion-recovery prepared gated fast gradient echo pulse sequence. This will produce high-resolution contrast-enhanced images of the ventricular myocardium that clearly defines the patient's zone of infarction, allowing for accurate measurements of infarct size and transmural extent.
Following MRI, patients will undergo ICD implantation with transvenous defibrillator systems selected by the patients' clinical physician. Patients will be followed over the course of 1 year and will be evaluated clinically after an ICD firing. The primary endpoint is to relate the MRI parameters of infarct size and transmural extent of infarction to the subsequent risk of "appropriate" ICD firing. Secondary clinical endpoints will also be collected, specifically death (cardiac and non-cardiac), recurrent MI, congestive heart failure, unstable angina requiring hospitalization, need for revascularization by PCI or CABG, and stroke.
Project 2: Comparison of 1.5 and 3.0 Tesla MR imaging in the evaluation of the
heart and abdominal aorta
Magnetic resonance imaging at 1.5 Tesla is now a standard tool for the evaluation of cardiovascular disease. It was used extensively in the Dallas Heart Study to evaluate myocardial mass and function and to assess the presence and extent of atherosclerosis in the aorta. Recently, clinical magnetic resonance imaging at 3.0 Tesla has become available which increases the signal which is obtained during imaging. In studies in the brain and body, it has been demonstrated that this additional signal can be used effectively to improve image quality or reduce scanning time. Thus, it could potentially be used in future cardiovascular studies to permit more rapid and extensive evaluation. However, to permit comparison with prior studies, it is important to prove that the imaging at 1.5 and 3.0 Tesla provide equivalent measurements.
Monica Mead
Medical College of Georgia
Mentor: Abhimanyu Garg
Internal Medicine / Center for Human Nutrition
With the introduction of Highly Active Anti-Retroviral Therapy (HAART), HIV has become a chronic illness in developed countries rather than a fatal disease. With the new medications and extended life expectancy come new challenges, including side effects of the drugs. Adverse effects of medications can effect treatment adherence and ultimately lead to emergence of resistant strains of HIV. Questions have arisen concerning the relative effects different classes of antiretrovirals have on metabolic disturbances, fat distribution and quality of life (QoL). My particular area of interest pertains to the effects of non-nucleoside reverse transcriptase inhibitors (NNRTI) versus protease inhibitors (PI) on health-related quality of life, which includes such subcategories as overall function, life satisfaction, health worries, financial concerns, burden of medication regimen, mastery of HIV, disclosure worries and body image. We have taken a cohort of treatment-naïve HIV-infected patients and randomized them to receive either an NNRTI or a PI, collected baseline QoL data and will continue to follow patients for two years. I am investigating which QoL subcategories are effected, to what extent and how do these effects progress during administration of HAART? The knowledge of what medication regimen correlates to adverse effects on QoL, as well as knowing when these events occur during treatment, will allow for administration of interventions at appropriate time periods, increased treatment adherence and decreased emergence of resistant strains of HIV.
2005-2006 Fellows of the University of Texas
Southwestern Doris Duke
Clinical Research Fellowship Program for Medical Students
(UT Southwestern-Doris Duke-CRF)
Sarah M. Barber
UT Southwestern
Department of Pediatrics
Mentors: Leah Adix, B.S.
George R. Buchanan, M.D.
Assessment of Risk Factors for Thrombosis in Persons with Hereditary Spherocytosis
1. Hypothesis:
Persons with hereditary spherocytosis (HS) who have had a splenectomy exhibit
more risk factors for venous and arterial thrombosis than HS patients who have
not had splenectomy.
2. Aim:
The aim of this study is to correlate the results of several laboratory measurements
which are surrogates for risk of venous and/or arterial thrombosis in children
and adults with HS who have either had or not had a surgical splenectomy. The
two groups of patients to be studied are as follows:
1) Children with HS followed in the Hematology-Oncology outpatient unit at Children's Medical Center Dallas (CMCD).
2) Parents and other adult relatives of children with HS followed at CMCD who also have HS.
The study will be conducted in two phases or parts. Part I will be a retrospective chart review of existing records of established hereditary spherocytosis patients. The IRB has provided expedited approval of the study. Part II consists of a prospective component including patient interviews and laboratory testing. This will require a separate IRB submission with the usual informed consent procedures.
3. Background:
HS and its Treatment With Splenectomy
HS is the most common congenital hemolytic anemia in the Caucasian population, with an incidence of approximately 1 in 5,000 (1,2). The disorder is usually inherited in an autosomal dominant fashion. It is due to one of a number of mutations in genes encoding red blood cell structural proteins, most frequently ankyrin or spectrin. These mutations lead to red cell membrane loss and fragmentation, such that the red cell assumes a spherical shape, rendering it inflexible and susceptible to destruction in the spleen. Clinical manifestations of HS include signs and symptoms of anemia, jaundice, gallstones, and acute anemic events. For decades it has been known that splenectomy "cures" the hemolytic anemia, so this operation has been considered by many the treatment of choice for the condition. Persons having had splenectomy are at increased risk of overwhelming bacterial septicemia. Although with appropriate preventive measures, this complication is now less frequent, much controversy and uncertainty remains in the medical community regarding which patients with HS should have splenectomy and when.
Thrombosis Following Splenectomy
During the past decade evidence has emerged that a second major complication of splenectomy is arterial or venous thrombosis. Case reports and small case series have described this complication in persons with HS as well as in patients having splenectomy for other reasons (3-9). Thrombosis also occurs in mice with HS following splenectomy (10). Greater knowledge about the incidence, age, and risk factors regarding thrombosis following splenectomy would be extremely important in helping to decide whether and when this procedure should be performed in affected patients. Our long-range research plan is to conduct a formal case control study of specific vascular complications (stroke, myocardial infarction, venous thromboembolism, pulmonary hypertension, etc.) in persons with HS having had splenectomy or not. There is evidence that splenectomy may increase platelet count, hemoglobin concentration, plasma cholesterol, leukocyte count, and C-reactive protein in persons with HS and possibly in other conditions as well (11-18). Patients with HS and other hemolytic anemias actually have relatively low plasma cholesterol levels, and this finding, plus their lower hemoglobin concentrations (and perhaps slightly lower platelet counts associated with splenomegaly), may protect them from thrombosis.
Laboratory Correlates of Thrombosis Risk
In Part II of this exploratory research study we aim to perform three or more laboratory tests - (1) complete blood count (for determination of the hemoglobin concentration, platelet count, and total leukocyte count), (2) total plasma cholesterol and its fractions (LDL and HDL cholesterol), (3) and C-reactive protein (CRP) in persons with HS of various ages whether they have had splenectomy or not. Values for each parameter will be compared in the two groups (splenectomy or no splenectomy) and corrected for age, gender, and other factors that might affect their results. A brief questionnaire will also be employed for each study subject to obtain health information regarding risk factors for thrombosis. Study subjects will be children with HS and their affected relatives who provide informed consent.
Given that HS is relatively common as a cause of hemolytic anemia, it is surprising that the literature contains so few data regarding laboratory correlates of possible thrombosis risk. The hemoglobin concentration usually returns to normal following splenectomy, since hemolysis is essentially abolished. However, the post- splenectomy hemoglobin values are actually slightly higher than normal (19). This may relate to the increased hemoglobin concentration in the erythrocyte. Few good data are also available regarding platelet count. It is generally acknowledged that platelet count rises immediately after splenectomy, but subsequently returns to normal. However, we have observed persistent thrombocytosis in patients with HS following splenectomy. Finally, the effect of chronic hemolytic anemia on plasma lipid profile has been little studied. Research at our center two decades ago showed decreased plasma cholesterol in children with sickle cell anemia compared to age- matched norms (11). Limited data are also available in HS patients suggesting lower cholesterol and triglyceride values. In sum, the lack of good data regarding these laboratory measures provides sound rationale for acquisition of such information as part of this study.
4. Study Design
Part I (July - November 2005):
" A list of all children with HS seen at Children's Medical Center Dallas since 1975 will be generated from the department's hematology database. Date of birth, medical record number, and other information available from the database will be recorded as well.
" Medical records will be collected from all sources (hematology/oncology shadow charts, files of inactive patients, scanned information from Millennium, and archived data from Children's Medical Records Department) from as many of these patients as possible.
" A flow sheet will be established for each patient that includes the following information: Name, medical record number, date of birth, gender, splenectomy status, family history (if known), and all available laboratory values for the following measurements: hemoglobin concentration, reticulocyte count, and platelet count.
" In select cases the medical record will be further reviewed for information regarding the date of splenectomy and dates of other complications that may have caused acute changes in hematologic perimeters.
Part II (November 2005 - June 2006):
" A prospective study consisting of a brief interview regarding risk factors
for thrombosis, disease status (confirmation of diagnosis of HS, splenectomy
status, and other illnesses that may affect blood count and cholesterol levels)
involving children with HS and any relatives (parents, aunt/uncles, grandparents,
etc.) with HS who are available for study.
" The following laboratory studies will be performed without charge, all
consenting subjects (regardless of age) in this phase of the study:
1) Hemoglobin concentration, Hematocrit, WBC count with Differential, Platelet
count
2) Reticulocyte count
3) Total, LDL, and HDL Cholesterol, triglycerides
4) Glucose
5) Plasma C Reactive Protein concentration
6) Fibrinogen
" Each patient will be studied only once.
Charles Bruen
UT Southwestern
Department of Surgery
Mentors: Thomas Anthony, M.D.
1. Medical Errors Study
Medical errors and the potential negative effects of these errors have on patient outcome has recently received a great deal of attention. Key studies arising from the Harvard Medical Practice Study, indicated that the number of these errors were significant and introduced a excess burden on the patient and health care costs.
Errors occurring during medication ordering and administration account for, a significant proportion of these errors and much of the attendant morbidity associated with them. Several potential solutions have been proposed include institution of electronic ordering which decreases the likelihood of errors through improved legibility and automated compatible checking when multiple medications are prescribed. The unintended consequences of this system including increased physician and nursing frustration, delayed medication delivery, and decreased personal vigilance. No studies have examined whether such an electronic system of order entry actually reduces medication errors or simply trades one type of error for another. The VAs electronic ordering systems are state-of-the-art and offer a unique opportunity to investigate this issue. Partnering with Nursing service, Pharmacy, and the Intensivist service in the Thoracic and Surgical intensive care units we are proposing a study to test the utility of electronic orders compared with paper ordering.
The Hypothesis of this study is that the error rate has not been reduced by the introduction and of these electronic physician order entry systems as compared to a traditional paper-based system in an ICU setting.
In this study, two different electronic and one traditional paper-based physician
ordering systems will each be used for a period of four weeks in the SICU and
TICU, and the three systems will be used serially. Using specific definitions
of medication errors, data will be collected on the error rate associated with
the use of each of these systems will be gathered and compared. There will be
three phases of the study, each lasting exactly fours weeks. For each phase,
data will only be gathered for patients that have consented to participate in
the study. During Phase I of this study, the SICU and TICU will remain on their
status quo procedures of recording and executing physician orders using the
CPRS system. In Phase II, the physician orders and execution will be done using
the CliniComp system. In Phase III, a traditional paper-based physician order
entry system will be used. During all phases, patients who are excluded from
the study will be treated using the standard procedures of each respective ICU
(ie. CPRS).
2. Vascular Health-Related Quality of Life Study
We have been collecting prospectively }IRQoL information on vascular surgery
patients for about 2 years. Approximately 150 patients have been entered into
this study. HRQoL is measured at the time of diagnosis, and then at 6, 12, and
24 months.
The hypothesis being addressed is that patients with peripheral vascular disease
and who undergo re-vascularization procedures will have improved HRQoL compared
with patients who do not undergo surgery. Upon completion this study will be
among the largest study to address this issue with validated HRQoL instruments.
Jason J. Chang
University of Kentucky
Department of Internal Medicine
Mentors: Gail Thomas, M.D. and Ronald Victor, M.D., Ph.D.
PURPOSE: To characterize the autonomic nervous system dysregulation in relation
to the early observed sinus tachycardia in children with Duchenne or Becker
muscular dystrophy (DMD/BMD) without any clinical signs of cardiac involvement.
BACKGROUND: DMD and the milder BMD variant is an X-linked condition characterized by progressive muscular wasting and weakness in early childhood leading to death from respiratory failure by early adulthood. While the life expectancy has increased due to the use of long-term noninvasive positive pressure ventilation, a growing prevalence in cardiomyopathy has been observed as well1. Clinically apparent cardiomyopathy may be detected by the age of 10, with all patients over the age of 18 displaying cardiac involvement2. Although advanced cardiomyopathy is often accompanied by arrhythmias and characteristic EKG abnormalities, a labile sinus tachycardia has been commonly observed in children with DMD before any clinical signs of heart failure3. The circadian heart rate variability of children with DMD is apparently blunted as well4. Although the basis of this regulatory imbalance remains unresolved, attenuated vagal efferent activity associated with nitric oxide modulation has been suggested as an major element4,5. Recently our laboratory has been able to demonstrate that children with DMD exhibit a functional muscle ischemia in exercising skeletal muscle not observed in control subjects due to a deficiency of neuronal nitric oxide synthase6. Whether this phenomenon is applicable to cardiac physiology is unknown. More insight regarding the nature of the dysautonomia will be valuable to understanding the significance of the sinus tachycardia relative to the terminal cardiomyopathy and should provide the impetus for more focused studies regarding the increasing prevalence of heart disease in this young population.
BRIEF PROJECT SUMMARY: At the first of two visits subjects will be asked to
perform four tests of autonomic nervous system functioning consisting of the
lower body negative pressure challenge, cold pressor test, deep metronomic breathing,
and sustained handgrip test. Twelve lead electrocardiogram (EKG), blood pressure,
heart rate, respiratory rate, hemoglobin oxygenation via near infrared spectroscopy,
and blood flow via doppler ultrasound as well as venous occlusion plethysmography
will be measured during each test. Twenty-four hour Holter monitoring heart
rate variability and twenty-four hour blood pressure measurements will be recorded.
We predict that there will be significant differences in autonomic responses
compared to control subjects. The subject will be asked to return after a week's
time for a magnetic resonance angiography and cardiac perfusion imaging study
when he will repeat the cold pressor test and lower body negative pressure challenge
while images are recorded from coronary arteries and gadolinium contrast perfusion
studies. EKG data will be evaluated for any signs of cardiac ischemia such as
ST segment changes during the four tests. If there is a cardiac equivalent of
the previously observed functional muscle ischemia, this will be evident on
magnetic resonance angiography and perfusion studies as a difference in coronary
artery vasodilation and myocardial perfusion compared to control subjects.
Vinu Ipe
UT Southwestern
Department of Internal Medicine
Mentor: Robert Toto, M.D.
Diabetic nephropathy is a public health crisis in the United States. The disease causes devastating complications in approximately 30% of both type 1 and type 2 diabetics, with progression to end-stage renal disease (ESRD) in nearly all of these cases. Diabetic nephropathy has become the primary cause of ESRD in the US and develops insidiously over 10-15 years and the morbidity and mortality are sharply increased with onset of nephropathy in both type 1 and type 2 diabetics. Moreover, death occurs within the first year after onset of ESRD in 17% of type 1 and 23% of type 2 diabetics.
Current standard of care of patients with diabetic nephropathy includes treatment with an ACE inhibitor and lowering blood pressure to < 130 / 80 mmHg. Inhibition of the renin-angiotensin-aldosterone system (RAAS) with ACE inhibitors (ACEi) in type 1 diabetics or angiotensin II type 1 receptor blockers (ARB) in type 2 diabetics have been shown to reduce risk of progression of diabetic nephropathy to ESRD. Unfortunately, in the vast majority of cases, renal function continues to decline at an accelerated rate despite these interventions. There are no well-controlled studies examining the impact of combining agents that inhibit the RAAS in diabetic nephropathy. The purpose of this project is to conduct a feasibility study testing novel drug combinations that block the RAAS at multiple sites, including the ACE enzyme, the angiotensin type 1 receptor and the aldosterone receptor, on proteinuria - a surrogate marker for renal disease activity in patients with established diabetic nephropathy. This feasibility trial could lead to a full-scale phase III clinical trial to test potentially promising strategies on hard clinical outcomes such as ESRD.
Major Hypothesis:
In patients with diabetic nephropathy, the addition of either an ARB or a MRA
to a maximally dosed ACE inhibitor-based regimen will afford greater renoprotection
than the ACEi-based regimen alone, and the added value of the MRA is specific
for aldosterone and is not explained solely on the basis of reduced time-integral
BP burden as assessed by 24-hour ambulatory blood pressure monitoring.
Specific Aims:
1. Recruit a multiethnic cohort of 90 adults age 20 to 65 with either Type 1
or Type 2 Diabetes and overt nephropathy (defined as a urine albumin/creatinine
ratio > 300 mg albumin/g creatinine) and randomize in a double blind fashion
to a control group consisting of ACEi-based therapy alone (lisinopril 80 mg
once daily) or one of two experimental groups: 1) ACEi + ARB (lisinopril 80
mg once daily plus losartan 100 mg once daily) or 2) ACEi + mineralocorticoid
receptor antagonist. (lisinopril 80 mg once daily plus spironolactone 25 mg
once daily).
2. Conduct a 12-month prospective study to determine if proteinuria is reduced
to a greater extent when either the ARB or MRA is added to ACEi-based therapy.
The study is powered to detect a 40% greater reduction in 24-hour urine albumin/creatinine
excretion ratio in either experimental group versus control with 24 patients
per group. Secondary endpoints to be examined include: (a) serum potassium and
creatinine to assess safety, (b) TGF-beta, as a surrogate marker for ongoing
renal injury, and (c) plasma lipids and lipoprotein composition.
3. Perform repeated ambulatory blood pressure monitoring to examine the renoprotective
effects of the 3 different regimens at comparable office and 24 hour blood pressure
levels of < 125/75 mmHg. Periodic measurements of glomerular filtration rates
will be done by overnight in-patient clearance studies at the GCRC.
This feasibility study will provide important new information for design of
subsequent large-scale trials of renoprotection in diabetic nephropathy: 1)
documenting safety of maximal dose combination therapy; 2) documenting the feasibility
of extensively utilizing 24 hour ABPM in large scale trials designed to establish
blood pressure independent renoprotective effects of specific antihypertenive
therapies; 3) providing promising new data for a future large-scale studies
to test the efficacy and safety of combining ACEi therapy with MRA therapy on
renal outcomes.
Phillip Kuan
Texas Tech University Health Sciences Center
Department of Internal Medicine
Mentor: Christine Kim Garcia, M.D., Ph.D.
Investigation of Familial Idiopathic Pulmonary Fibrosis
Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing disorder of the
lungs defined by characteristic pathologic, clinical, radiographic, and physiologic
characteristics. It is the most deadly of the idiopathic pneumonias with no
known cure and no consistently effective treatment. The prognosis is poor, with
a mean survival of fewer than 3 years from the time of diagnosis. The familial
form of the disease is rare, accounting for 0.5 - 3.7% of all the cases of IPF.
The molecular basis of the familial form of the disease is unknown. We hypothesize
that familial idiopathic pulmonary fibrosis is a rare disease displaying an
autosomal dominant pattern of inheritance with variable penetrance. To test
this hypothesis we have established a collection of families with familial idiopathic
pulmonary fibrosis (IPF) through patient contact and referrals. This proposal
seeks to characterize affected and at-risk family members by clinical and molecular
methods. Each participant will undergo a physical exam, submit blood for routine
analyses, have pulmonary function testing, a cardiopulmonary exercise test,
a high-resolution CT (HRCT) scan, and undergo bronchoscopy to evaluate bronchoalveolar
lavage fluid for markers of inflammation and fibrosis. The pulmonary function
testing will include spirometry, body plethysmography, diffusion capacity measurement,
and oxygen desaturation with exercise. This is a novel type of study using our
unique resources of families with familial IPF. If the pattern of inheritance
is indeed autosomal dominant with reduced penetrance, then this type of screening
of adult at-risk family members may identify some individuals with early findings
of the disease or may identify an intermediate phenotype of the disease. These
studies will directly complement our investigation of the genetic basis of this
disease by classical linkage techniques and by analysis of candidate genes.
Eugene Limanovich
University of New Mexico School of Medicine
Department of Internal Medicine
Mentor: Ronald Victor, M.D., Ph.D.
African American men suffer more from early cardiovascular disability and death from uncontrolled hypertension in than any other group in the United States. In studies spanning three decades, hypertension awareness, treatment, and control have been consistently worse in Black men than in the general population. Among Black men ages 18-64 with hypertension in the Dallas County, Texas, currently 47% are unaware of their condition, 60% are not being treated with medication, and only 14% are receiving a treatment regimen that lowers their blood pressure (BP) below the minimally acceptable value of 140/90 mm Hg. These age-adjusted rates are much lower than those in Black women, white men, or white women in the same county. To better control hypertension in Black men, we propose a well-informed and feasible behavior theory-based intervention conducted by their barbers, influential peers who will reach out to their customers and model effective strategies for reducing the serious health risks caused by hypertension.
Target Population: Black men who patronize Black-owned barbershops that cater to Black men
Major Hypothesis: Sustained efforts by barbers to continually monitor BP in the barbershop, deliver health messages, and provide social support for desired changes in healthcare-seeking attitudes and behaviors will be more effective than no active intervention for controlling hypertension in Black men.
Specific Aims: Among the adult Black male customers with hypertension, the
specific aims are:
1. To increase the proportion of adult Black male barbershop customers with
hypertension in whom systolic BP is less than 140 mm Hg and diastolic BP is
less than 90 mm Hg.
2. To increase the measurement of BP in the barbershop and the recognition of
elevated BP readings.
3. To increase the utilization of regular medical providers for chronic BP management.
Nichole Manhert
University of Wisconsin
Mentors: Jeanne Sheffield, M.D. and Gretchen Stuart, M.D.,
MPHTM
Oral Contraceptive Pill continuation in a Dallas Family Planning Clinic
Background: Over 30% of reproductive age women are currently using oral contraceptive
pills and over 80% of all women born after 1945 have ever used oral contraception.
Oral contraception is highly effective when used perfectly, but typical use
is associated with an 8% failure rate in the first year. Problems with compliance
and discontinuation account for an estimated 1 million unintended pregnancies
and associated costs of about 2.6 billion dollars. Previously published literature
demonstrates that discontinuation rates range from 32% to 60% in the first year.
The continuation rate of oral contraceptives in our clinic is important in that
we have a unique population that is predominantly Latina with continuation rates
that we suspect are higher than previous literature cites.
Objective: To determine the continuation rate of oral contraceptive pills among
female patients at the Maple Community Women's Health Center. Secondarily, we
hope to assess the feasibility of a future study to determine if an intervention
will increase continuation rates of oral contraceptive pills.
Study Design: This is a descriptive study using medical charts to determine
the characteristics and continuation rate of women seen at the Maple Community
Women's Health Center to initiate oral contraceptive pills from May 2002 to
April 2003.
Results: Once the data is compiled we will use descriptive statistics to assess
the study population. We will calculate the baseline continuation rate and then
evaluate the characteristics of women who continue birth control versus women
who discontinue at three months and at twelve months.
Conclusions: Results may yield important information that can then be used to
enhance quality of care delivery and improve continuation rates of oral contraceptive
pills in out clinic population.
Brendon O'Neill
Drexel University
Mentor: Abhimanyu Garg, M.D.
1. Primary responsibility for a study titled "Fish Oil for the Treatment
of Hyperlipidemia in HIV+ Subjects on Protease Inhibitor Combination Therapy."
With the advances in anti-HIV therapy, particularly the multi-drug regimens
that include protease inhibitors, long-term survival of HIV infected patients
is now expected. However, such therapy has led to the development, in some patients,
of a syndrome characterized by lipodystrophy, dyslipidemia, impaired glucose
tolerance, and sometimes diabetes mellitus. The dyslipidemia is characterized
by hypertriglyceridemia and a lowered concentration of high density lipoprotein
cholesterol. In the proposed study, we will investigate the short-term safety
and efficacy of fish oil in lowering plasma triglycerides and LDL cholesterol
levels in HIV+ subjects with hyperlipidemia (TG > 300) associated with protease
inhibitor therapy. Secondary end-point variables will include plasma VLDL-cholesterol,
HDL-cholesterol, insulin, and fasting glucose concentrations. The study will
be a double-blind, randomized, placebo-controlled cross-over trial. Each of
our two treatment arms will be 6 weeks duration with three sets of fasting labs
and an outpatient check-up visit at the end of each treatment period. Daily
activities will include screening and enrollment of patients for the study,
following the patients through the study at their outpatient visits, and managing
our database.
2. The metabolic and molecular basis of lipodystrophy syndrome in HIV-infected
patients is not known. Whether besides PIs, other antiretroviral drugs, HIV
infection and reduction in viral load contribute to the development of lipodystrophy
syndrome is not clear. The project therefore has the following aims: 1) to characterize
metabolic abnormalities and changes in body fat distribution, 2) to develop
objective criteria for defining the syndrome and to ascertain prognostic indicators
and 3) to elucidate the molecular basis of the lipodystrophy syndrome in HIV-infected
patients. To accomplish these aims, we will conduct a 2-year long prospective,
randomized, double blind, placebo-controlled study in asymptomatic HIV (+) patients
to compare two equally effective antiretroviral regimens, one with and the other
without a PI. We will study body fat distribution by anthropometry and magnetic
resonance imaging and will measure insulin sensitivity (in a subset of patients),
plasma lipoproteins, glucose tolerance and other metabolic variables. We will
study expression of an array of adipocyte specific proteins/transcription factors
involved in adipocyte differentiation, insulin action and lipoprotein metabolism
in fat biopsy samples obtained before and after institution of therapy. Identification
of the metabolic and molecular basis of lipodystrophy syndrome in HIV (+) patients
may lead to better understanding of role of adipocyte-specific genes in insulin
action and body fat distribution and may lead to discovery of other antiretroviral
drugs that do not cause the lipodystrophy syndrome. My involvement will be in
a) recruiting/screening patients, b) conducting inpatient and outpatient visits
every three months to follow any changes in metabolic profile/HIV suppression
c) monitoring and updating the database d) performing skin fold anthropometry,
underwater weight, and oral glucose tolerance tests e) assisting with DEXA,
MRI, MRS data analysis f) participating in adipose and muscle biopsy procedures
and preparing the samples for molecular analysis.
3. In addition to primary responsibility in the Fish Oil therapy trial, I will
participate in the overarching project titled: Therapeutic Interventions in
HIV-associated Lipodystrophy. In this larger project, we propose to investigate
potentially safe therapeutic lifestyle changes as well as novel therapies for
its management. The project therefore has the following aims: 1) to compare
acceptability and metabolic effects of diets rich in carbohydrates and cis-monounsaturated
fats, 2) to compare effects of a supervised aerobic exercise regimen and dietary
advice to dietary advice alone on metabolic variables and body fat distribution,
3) to compare lipid-lowering effects of n-3 polyunsaturated fats to placebo
(Fish Oil Study) and 4) to study the efficacy and safety of recombinant methionyl
leptin (r-metHuleptin) in improving insulin sensitivity, dyslipidemia and body
fat distribution in patients with HAART-induced lipodystrophy. To accomplish
these aims, we will enroll ~124 patients with HAART-induced lipodystrophy or
metabolic complications in randomized, crossover studies (aims 1 and 3) and
randomized, parallel design studies (aims 2 and 4). We will study body fat distribution
by anthropometry, dual energy X-ray absorptiometry and magnetic resonance imaging
and will measure insulin sensitivity (aims 2 and 4). We will study plasma lipoproteins,
glucose tolerance, and other metabolic variables (all aims). Our results may
help in designing therapeutic approaches to HAART-induced lipodystrophy and
its metabolic complications.
4. I will also see patients with Dr. Garg who have rare, inherited forms lipodystrophy.
I plan to learn the process of investigating unknown genetic etiologies through
the use of well-defined pedigrees, genome-wide linkage analysis, and the examination
of candidate genes for mutations. Studying single-gene disorders of adipose
tissue may aide our understanding of how adipose tissue disorders lead to insulin
resistance and other metabolic abnormalities.
2004-2005 Fellows of the University of Texas
Southwestern Doris Duke
Clinical Research Fellowship Program for Medical Students
(UT Southwestern-Doris Duke-CRF)
Holly Barko
UT Southwestern
Department of Pediatrics
Mentors: Greg Jackson, M.D. and William Engle, M.D.
I. Association of hypocalcemia with a change in gentamicin administration
schedule in neonates: (IRB submitted and approved)
Approximately 15-30 neonates are evaluated in the NBN each month with suspected
sepsis and are treated with ampicillin and gentamicin for >4 days duration.
A previous retrospective study examined the increased incidence of hypocalcemia
with a change in gentamicin dosing schedule (from a lower dose every-12-hour
regimen, to a higher single-daily-dose regimen). This study will compare changes
in serum and urine electrolytes in neonates treated with two different dosing
schedules of gentamicin (q 12h vs. q 24h). Based on the results of a previous
study, the investigators have hypothesized that q24h dosing of gentamicin results
in either altered urinary excretion of calcium and magnesium and/or disruption
of the calcium-sensing receptor of the parathyroid gland, thus increasing the
risk for hypocalcemia when compared to q12h gentamicin dosing. Fifty term or
near-term neonates will be selected for the study who are *35 weeks gestation
and *2100 grams, and who do not require NICU care. The study neonates will be
given gentamicin in a dosing schedule of either 2.5 mg/kg*dose q12h or 4mg/kg*dose
q24h, for 7-10 days. Blood and urine samples will be taken at 0 hours (before
gentamicin is administered), 50 hours, and 122-143 hours for each group of infants,
and data collected will include serum BUN and Cr, electrolytes, total Ca and
ionized Ca, PTH, and albumin; also urine Ca/Cr, FENa, FEK, FEMg, FEPhosphate,
and urinalysis. The data collected will help determine whether significant electrolyte
and/or parathyroid hormone effects occur as a result of a once-daily gentamicin
dosing regimen.
II. Parenteral vs. parenteral-oral antibiotic therapy for term and near-term
neonates with suspected pneumonia: (development of the project summary is nearing
completion).
This study will compare outcomes of two groups of neonates, each group consisting
of approximately 40 neonates, who are being treated with antibiotics for suspected
pneumonia and whose symptoms rapidly resolve. One group will receive the standard
regimen of 5-7 days of parenteral antibiotics (ampicillin and gentamicin), while
the study group will receive parenteral antibiotics for at least 48 hours and
then (if the neonates have been asymptomatic for 24 hours) parenteral antibiotics
will be discontinued and oral amoxicillin/clavulanate (Augmentin®) will
be administered for a total of 7 days. It is anticipated that the neonates in
the oral medication group will be discharged after 2 days of beginning oral
therapy; these neonates will be examined by one of the investigators within
several days after discharge. Pharmacokinetic studies of Augmentin® in this
population are also being considered. If the parenteral-oral antibiotic therapy
for neonatal pneumonia proves to be as effective for these selected neonates
who readily respond, the potential benefits to patients would include fewer
needle sticks (for IVs and gentamicin blood levels), decreased exposure to a
potentially nephrotoxic drug (gentamicin), and a shorter hospital stay.
III. Antibiotic therapy for neonates exposed to maternal chorioamnionitis (study
is in the early stages of conceptualization)
In this study the investigators will identify women who have the obstetrical
diagnosis of chorioamnionitis during labor at Parkland Memorial Hospital. All
neonates in the study will be asymptomatic; those who develop symptoms will
receive more prolonged antibiotic therapy and will not be included in the study.
The investigators are considering the entry definition to include a certain
time period of intrapartum maternal treatment with antibiotics (e.g., entry
criteria may include those neonates whose mothers have received ampicillin and
gentamicin at least 4 hours prior to delivery).
Neonates who are not exposed to chorioamnionitis currently receive a single
dose of aqueous penicillin within one hour of birth as prophylaxis to reduce
the incidence of neonatal Group B streptococcal disease. The control group will
consist of continuing the current approach to asymptomatic neonates exposed
to maternal chorioamnionitis at PMH , i.e., obtain a blood culture and administer
ampicillin and gentamicin intramuscularly (IM) for a 48-hour course. The study
group will be given a single IM dose of penicillin (after a blood culture is
obtained) and then be observed closely for 48 hours. The clinical outcomes of
the two groups will be compared, and will require follow-up examinations and
phone contact. If the single IM dose of penicillin (in combination with intrapartum
maternal antibiotics) proves to be as effective as the standard therapy of ampicillin
and gentamicin IM for a 48-hour course, then asymptomatic neonates exposed to
maternal chorioamnionitis could in the future be treated with a regimen that
involves fewer painful IM injections and a reduced exposure to broad-spectrum
antibiotics.
IV. Accuracy of the BiliStat machine compared with the laboratory-measured
total serum bilirubin (study has been IRB-approved)
The BiliStat machine, approved for use in Europe to quickly determine
serum bilirubin levels as a patient point-of-care device, has not yet been approved
for use in the United States. The investigators have been in contact with the
manufacturers and distributors of the device, who wish to collaborate on a project
in the Parkland Newborn Nursery that will validate the use of the BiliStat
for FDA approval. Patients will include those who are undergoing a blood specimen
for either a bilirubin level to assess jaundice, or those who are undergoing
a blood specimen for the routine newborn screening tests.
The study will compare serum bilirubin levels performed at Parkland Memorial
Hospital Laboratory (Olympus AU600, which utilizes the Jendrassic-Grof with
blank method) with the BiliStat, which utilizes a centrifuge and concurrent
laser spectrophotometry (dual-wave flame photometry) technology. A technical
issue involving the safety of the self-sealing glass tube for specimen collection
is close to a satisfactory conclusion. In addition, transcutaneous bilirubinometry
with the Air-Shields Minolta JM103 Jaundice Meter (FDA-approved) will
be performed on the same patients. Comparisons of these 3 determinations (Olympus
AU600, BiliStat, and the JM103 Jaundice Meter) will then be performed.
The advantage of the BiliStat is the rapidity of the bilirubin testing,
which could reduce delays in hospital discharge.
Suzie Chang
Georgetown University
Department of Neurology
Mentor: Abhimanyu Garg, M.D.
Co-mentor: Anil K. Agarwal.
Title:"Study of molecular heterogeneity of adipose tissue"
Purpose: To determine the underlying heterogeneity of various adipose tissue depots according to respective anatomic location using differential expression of various adipocytokines and adipocyte enzymes.
Background:
Congenital Generalized Lipodystrophy is characterized by a near complete absence
of body fat and extreme insulin resistance from birth. Less than 200 cases with
CGL have been described in the literature. Other clinical features include acanthosis
nigricans, marked hyperinsulinemia, hypertriglyceridemia, and the onset of diabetes
mellitus mostly during pubertal years. The patients may have hepatosplenomegaly,
acromegaloid appearance (enlarged hands, feet, and prominent mandible), umbilical
hernia, and in women, clitoromegaly, hisutism, oligo/amenorrhea and polycystic
ovaries. They have extremely low serum leptin and adiponectin levels. Affected
children have accelerated growth, voracious appetite, increased basal energy
expenditure, and advanced bone age. Fatty infiltration of the liver occurs early
and may lead to cirrhosis. Other reported features include mild mental retardation,
cardiomyopathy, and hypertrichosis.
Our studies of phenotypic heterogeneity among two types of CGL revealed that
patients with CGL1 (with AGPAT2 mutations) have near complete absence of "metabolically-active"
adipose tissue located in most of the subcutaneous (sc) areas, intraabdominal
and intrathoracic regions, bone marrow, and parathyroid glands, but "mechanical"
adipose tissue in the orbis, crista galli, buccal region, tongue, palms and
soles, scalp, perineum, vulva, peri-articular regions, epidural area and pericalyceal
regions of the kidney is well preserved in them. In contrast, patients with
CGL2 (with BSCL2 mutations) have marked lack of both metabolically active and
mechanical adipose tissue. The relative expression of various AGPAT isoforms
in adipose tissue from different anatomic locations has not been studied. Thus,
we will investigate if this particular fat loss in CGL1 patients is due to differential
expression of AGPAT isoforms or other adipocyte specific genes.
Concise Summary of Project:
Tissue mRNA expression studies: Adipose tissue from various anatomic sites (where
available) and liver, skeletal muscle, lung and pancreas will be excised and
analyzed for the global gene expression (gene chip experiments). If a particular
gene of interest, e.g., from triglyceride or phospholipids biosynthetic pathways
or lipodystrophy genes implicated in humans and mouse models, is not represented
on the selected gene chip, mRNA expression for such gene will be studied by
real time RT-PCR.
Furthermore, where possible, if enough tissue is available, we will isolate
the adipocytes and culture the cells to determine adipocytokines secretion such
as leptin, adiponectin, resistin, etc. We may also use to study protein expression
in adipose tissue and adipocytes from various sites using global protein analysis
(proteomics).
We will obtain human fat from various sites as listed below: scalp, temporal
region, cheek, retro-orbital, eyelid, chin, anterior neck (supra-clavicular),
posterior neck (dorso-cervical), arm, forearm, palm, axilla, anterior chest,
intra-thoracic (around pericardium), abdomen anterior, abdomen posterior, omental,
intra-peritoneal, retroperitoneal, peri-renal, pericalyceal (inside kidney),
pubic, vulvar, gluteal, thigh anterior, thigh medial, calf, sole, peri-articular
(around hip and knee joints).
Small quantities (up to 1.0 gm) of these tissues will also be obtained from
the organs involved in insulin action, production and phospholipids synthesis:
muscle, liver, lung, and pancreas.
Fat will be collected from patients undergoing elective surgery, from organ
donors who consent to donate their bodies for research and from discarded adipose
tissue during various surgical procedures. Skeletal muscle, pancreas, lunch
and liver will only be obtained from organ donors.
Anne Chung
University of Arizona
Department of Internal Medicine
Mentor: Mark Drazner, M.D., Ph.D.
Relationship Between Left Ventricular Volume and Ejection Fraction
Left ventricular (LV) ejection fraction (EF) has traditionally been used to
classify heart failure (HF) into diastolic and systolic heart failure. However,
it has recently been proposed that EF is acting as a proxy for left ventricular
(LV) volume and that measuring LV volume is a more accurate reflection of the
underlying cardiac physiology and may therefore be a more useful diagnostic
and prognostic measure in HF. To our knowledge, there is no prior analysis by
cardiac MRI of the relationship of LV volumes and LVEF. The Dallas Heart Study
appears ideally suited to address this question. The aim of this work is to
explore the linear relationship between EF and LV volume in the Dallas Heart
Study (DHS). We also will explore whether other factors (e.g. gender, obesity,
ethnicity, and history of heart failure) modulate the relationship of LVEF and
LV volume.
Chronic Heart Failure in Patients Treated at an Urban County Hospital
A retrospective chart review will be performed on patients treated at St. Paul's
congestive heart failure clinic and Parkland's congestive heart failure clinic.
We will compare the outcomes of the patients treated at an urban county hospital
to the outcomes of the patients treated at a private hospital. Patients at St.
Paul and Parkland are treated by the same physicians. This analysis will help
us understand the effect socioeconomic status has on the outcomes of heart failure
patients.
Non-Synonymous Single Nucleotide Polymorphisms Associated with Cardiac Outcomes
We will be comparing non-synonymous SNPs to observe for conservation across
species and association with cardiac outcomes and risks. We will be using SNP
data collected from the Dallas Heart Study to observe frequency of the variants
in this population.
Mark Muir
UT Southwestern
Department of Neurology
Mentor: Michael Racke, M.D., Ph.D.
For my Doris Duke research project I will be working in the neuro immunology
lab under the direction of Dr. Michael Racke. This lab is closely associated
with the Multiple Sclerosis Clinic at St. Paul, which follows roughly 4000 patients
on an ongoing basis. This allows for efficient transfer of data and ideas in
both directions, with laboratory research being translated directly into clinical
trials and clinical observations leading to the design of lab experiments. In
this manner, I will be involved with a project that is currently underway, and
that is attempting to correlate enormous amounts of patient data into a single
database. The study, which has already begun and is still enrolling patients,
is currently focused on correlating lab, imaging, and clinical measurements
to follow the progression and activity of MS and find more accurate methods
of estimating prognosis. The patients in the study are seen on a regular basis,
at which time blood is drawn, a gadolinium enhanced MRI is performed, and they
undergo a clinical neurological evaluation using a standardized neurological
disability scale. The MRI's are evaluated by a blinded neuroradiologist so that
presence or absence of enhancing lesions can be correlated with the other data
obtained.
My role in this project, in addition to seeing the study patients in clinic
with my mentor, entails analysis of a potential new therapy for MS using PPAR
agonists, a class of drugs that have been used extensively for decades in the
treatment of hyperlipidemia. Two common examples used in humans are gemfibrozil
and fenofibrate. These drugs have been shown to cause clinical improvement in
the mouse model of MS (Experimental Autoimmune Encephalomyelitis mouse). The
mechanism that is believed to be at least partly responsible for this observation
is that the PPAR agonists cause CD4+ Th0 cells to differentiate selectively
into a Th2 rather than Th1 phenotype in the presence of stimulation by antigen.
This is consistent with the current thinking that MS is an autoimmune disease
mediated in large part by self reactive Th1 cells specific for certain proteins
in myelin. The ultimate goal based on these observations is the development
of a clinical trial in human MS patients to test the effectiveness of this class
of drugs, either as monotherapy or in combination with other medications. These
drugs (PPAR agonists) are an ideal target of a clinical trial because of their
long track record of safety and minimal side effect profile established over
many years, and additionally they are cheap and widely available to patients
and physicians.
But before a clinical trial is begun, these drugs need to be tested in vitro
on human leukocytes to determine if they have the same molecular effects as
seen in the mouse models. Presumably, if the same effects are seen in human
cells and these drugs have a strong effect on the mouse model of MS, the evidence
will justify undertaking a clinical trial. My area of research involves determining
the specific changes caused by these agents in human T cells using the blood
samples from the patients enrolled in the study mentioned above. When blood
is collected from the patient, it is spun down and separated into its components.
I then take the isolated leukocytes, stimulate them with antigen, and culture
them in the presence or absence of PPAR agonists. From these cultured cells,
RNA is isolated and run on micro array chips. When analyzed, these chips reveal
whether there is up-regulation, down-regulation, or no significant change between
the two conditions for 32,000 human genes. In order to analyze the data from
a micro-array chip and derive meaningful conclusions, I am working to learn
the GeneSpring software used by UTSW. This software not only allows one to analyze
data and format it appropriately for either presentation or publication, but
also provides for correlation between sets of patient micro-array data and their
clinical information, in this case MRI and neurological disability scores. Ideally,
we hope to find the same or similar gene activation patterns in the human lymphocytes
as in the mouse lymphocytes, suggesting that PPAR- agonists may cause preferential
Th2 differentiation in humans as well. The results of these experiments, along
with several related experiments being conducted by others in the lab, will
pave the way for a full scale clinical trial using the PPAR agonists. The large
patient population followed in the MS Clinic provides an ideal setting for recruiting
and following patients in this type of study.
Once sufficient data has been gathered on the PPAR- agonists, I will begin experiments
with a related class of drugs, the PPAR- agonists. These drugs have also been
in use for some time in the form of insulin-sensitizing thiazolidinediones,
particularly troglitazone and pioglitazone. While these drugs seem to act through
an independent pathway, they have similar effects to PPAR- agonists on T cell
differentiation and on the mouse MS model. Another laboratory aspect of this
study involves using flow cytometry to determine a quantitative measure of the
number of each group of lymphocytes in a given subject. This flow cytometry
data is compared between healthy control subjects and MS patients to gain a
sense of which types of peripheral blood leukocytes contribute to the pathogenesis
of MS. While I will not be directly involved in this aspect of the study, the
flow cytometry data may provide clues to other classes of agents to experiment
with, particularly drugs known to alter either lymphocyte differentiation or
cytokine production by lymphocytes. The ultimate objective of each of these
related projects is to initiate a randomized placebo-controlled clinical trial
to test the effectiveness of these agents as a potential new therapy for multiple
sclerosis. However, the clinical trials are still some way off and may not be
entirely underway before the end of my Doris Duke Fellowship. This would give
me the opportunity to continue this research during my final year of medical
school.
Sandra Saldana
University of Vermont
Department of Internal Medicine
Mentor: Marlyn Mayo, M.D.
TITLE: PREDICTION OF DISEASE PROGRESSION IN PRIMARY BILIARY CIRRHOSIS BY A NOVEL
COMBINATION OF SURROGATE MARKERS.
PURPOSE:
The overall goal of this project is to take advantage of the clinical specimens
and extensive clinical database being collected in the Primary Biliary Cirrhosis
Ursodiol Methotrexate/Placebo Study (PUMPS, NIHR01DK46602) to identify the most
accurate surrogate marker of disease progression. Surrogate markers are badly
needed to advance clinical, epidemiological, and translational research in the
field of primary biliary cirrhosis (PBC), because the progression to hard endpoints,
such as death, commonly takes 10 to 30 years.
SPECIFIC AIM:
To compare the ability of novel combinations of serum markers of fibrosis, biochemical
tests, clinical factors, and liver histology to predict future development of
portal hypertensive complications in PBC patients.
METHODS:
PUMPS is a multi-center double blinded placebo randomized trial that was originally
design to compare the effect of ursodiol plus methotrexate vs ursodiol plus
placebo on the course of patients with PBC. The study randomized 265 patients
at 11 sites and then followed for approximately 8 years. Participants were evaluated
every 3 to 6 months, and at each visit blood was collected for CBC with differential,
platelet count, liver function test, and extra serum was stored. On a biannual
basis patients underwent liver biopsy, abdominal ultrasound and upper endoscopy.
Over the years, this study has accumulated an extensive amount clinical data
and of samples from patients with PBC. In March 2004, the randomization code
was broken and methotrexate was found to have no effect on survival or complications
on liver disease. However, a subset of individuals continues to be followed
on ursodiol alone at UTSW GCRC.
This study will utilize the PUMPS population to compare the ability of different
putative surrogate markers of disease severity to predict progression to clinical
endpoints. The surrogate markers to be studied include:
1) A novel algorithm derived from a panel of non-invasive markers, including
10 serum markers of fibrosis (listed below) and other clinical variables such
as age, bilirubin, alkaline phosphatase, platelet count, albumin, and INR. The
serum markers of fibrosis
were selected primarily on the basis that they have previously being shown to
correlate with histological fibrosis in the liver in studies of other chronic
inflammatory liver disease. They include hyluronic acid (HA), tissue inhibitor
of metalloproteinase (TIMP-1), amino terminal precollagen peptide III (PCPIII),
collagen IV, tenascin, undulin (collagen XIV), laminin P1, matrix metalloproteinase-2
(MMP-2), procollagen I carboxyterminal propeptide (PICP), and collagen VI. These
measurements will be done in collaboration with Dr. William Rosenburg, M.D.
at the University of South Hampton, UK.
2) Four-point histological fibrosis stage (Ludwig)
3) Four point histological fibrosis stage (Knodell)
4) Seven point histological fibrosis stage (Ishak)
5) Frequency of florid duct lesions
6) Risk score from the Mayo Prognostic Model for PBC
7) Age-platelet index
8) European Liver Fibrosis (ELF) Algorithm
The clinical end points that will be evaluated include: Development of varices,
variceal bleeding, development of ascites, development of encephalopathy, transplant,
and liver-related death.
This project will strive to create a new algorithm that will include a panel of serum markers of fibrosis, which would be superior at predicting future clinical decompensation than histological or other algorithms.
Some of the experiences that will be gained while undertaking this project
include but are not limited to: modification and submission of an IRB protocol;
seeing PBC patients enrolled in PUMPS at the UTSW GCRC and monitoring their
disease progression; collection of clinical data and entry into study database;
working with GCRC informatics core and biostatistians to graph disease progression
and analyze ability of non-invasive markers to predict decompensation. The latter
will include use of binary logististic regression and time-dependent Cox proportional
hazards modeling, Sigma Plot graphics software, Microsoft Access, and Microsoft
Excel.
Ryan Swinney
University of Southern California
Department of Internal Medicine
Mentor: Gail Tomlinson, M.D., Ph.D.
Introduction Genetic mutations have been recognized as one of the primary
etiological factors in the development of cancer. Pediatric cancers present
a paradoxical situation wherein cancer is present, yet seemingly insufficient
time has elapsed for the sufficient genetic "hits" to accrue for cancer
to develop. Recently, heritable genetic mutations have been investigated as
potential cancer predisposing factors. Specifically, mutations in the function
of TP53, RB1, and VHL genes have all shown functional roles in the development
of sarcomas, retinoblastoma, and hemangioblastomas in children. However, research
investigating predisposition factors in the etiology of the most common pediatric
cancer, leukemia, still remains in its infancy. Preliminary research has suggested
the role of mutations in Phase I and Phase II xenobiotic metabolizing enzymes
in the development of leukemia. Nevertheless, much more work is needed in order
to better elucidate these mutations' role in the etiology of leukemia.
To date, no study to date has specifically investigated differences in mutation prevalence in different populations of children with leukemia. Specifically, little has been done in minority populations such as the Hispanic and African-American populations, which constitute a substantial portion of the leukemia caseloads in our and many other pediatric hospitals. Such variations in mutation prevalence could explain the variable assortment of cancer predispositions in these different populations, and better elucidate why certain children are more/less predisposed to different forms of leukemia. It has also been speculated that the differing prevalences of these mutations in different ethnic groups might account for the variable responses to treatment that children experience when placed on a common chemotherapeutic regimen. Furthermore, current advances in cancer treatment suggest that unique "patient-specific" chemotherapeutic regimens might soon become the model of treatment, but this will only be possible with further elucidation of specific enzymes variations between patients which would effect treatment success and toxicity.
Therefore we have developed this case control study of Hispanic, African-American and Caucasian children, wherein we will seek to determine if different genetic factors might contribute to leukemia development. DNA samples (n ~360) were collected from leukemia patients in the hematology/oncology ward at Children's Medical Center of Dallas (CMC), and these samples will be matched by age, ethnicity, and sex to samples obtained from the out-patient clinics at CMC. All samples will be subjected to PCR-ASO testing for specific, pre-established polymorphisms in phase I and phase II enzymes known to have etiological roles in other cancers:
" CYP3A4, CYP1A1, CYP2D4, CYP1E1
" N-acetyltransferase 1 and 2
" Glutathione-S-transferase mu1, pi1, theta1
" Myeloperoxidase
Upon completion of data collection, these samples will be analyzed to determine:
" If significant differences in prevalence exist between the different
ethnic groups
" If any polymorphisms are significantly associated with leukemia when
cases are compared to their matched controls
" If different combinations of mutations have synergistic/interactive effects
on cancer risk
It is our hypothesis that each ethnic group should have its own novel mutation
profile, in a fashion suggested by prior epidemiological research. We anticipate
that this study will better elaborate on these prior findings, and more succinctly
compare the mutation variations between these communities. In addition, we expect
that our study may find novel differences between cases and controls of the
same ethnicity, which should elucidate how different mutation profiles may function
in the etiology of leukemia. Finally, we anticipate that the effects of combinations
of mutations in several xenobiotic metabolizing enzymes should have synergistic
effects on leukemia predisposition.
Methods:
Samples: DNA samples were obtained via blood draw from roughly 360 children
diagnosed with B-lineage leukemia over the past 5 years. All samples where amplified
via PCR and stored as part of a separate investigation protocol, and will be
accessed for this study. Matched controls from non-leukemic children will be
obtained from residual blood left over from blood draws in the Childrens Medical
Center laboratory. Cases and controls will be matched based on sex, age, and
ethnicity information that were retained from the patient's medical charts.
All other identifying information has withheld from this study's investigators.
The controls and cases will be amplified via standard polymerase chain-reaction, and subsequently sequenced for novel polymorphisms in the prestated enzymes via allele-specific oligonucleotide analysis utilizing primers obtained from prior research studies. Each patient will be identified as either homozygous or heterozygous for the wild-type and mutations alleles. All protocols have been approved by the Institutional Review Board.
Upon completion of data analysis, all data will be analyzed by an independent biostatistician at UT Southwestern Medical Center, who will construct odds ratios, significance values, and confidence intervals for each mutation between the different ethnic groups and the case/control dyads. The alpha value will be set at the standard .05 value, and any value found to have a p-value below this will be considered significant. Currently, power studies are being completed to determine if our sample sizes are sufficient and what the smallest detectable difference in values should be. (need to update after power calculations done)
Jennifer Tang
Baylor College of Medicine
Department of Internal Medicine
Mentors: Gretchen Stuart, MD, MPHTM and Jeanne Sheffield, MD.
1) "Hepatitis B Vaccination of High-Risk Pregnant Women" with
Dr. Jeanne Sheffield.
The Hepatitis B vaccine was approved in 1981 and has been very effective in decreasing the incidence of Hepatitis B in certain high-risk groups, such as healthcare workers. Large-scale universal immunization programs for infants and adolescents have resulted in a dramatic decrease in morbidity and mortality in these age groups. However, studies indicate that prevalence rates of Hepatitis B infection have not been significantly reduced in high-risk pregnant women. In 1993, the American College of Obstetrics and Gynecology recommended that high-risk pregnant women be vaccinated for Hepatitis B during pregnancy. This was both to reduce the maternal risk of contracting the disease and vertically transmitting it to the fetus, and to reduce the risk of future infection in the mother. "High-risk" was defined as those women in the healthcare field, intravenous drug users, and those with sexually transmitted diseases. Furthermore, the 1998 "Guidelines for Treatment of Sexually Transmitted Diseases" published by the CDC states that pregnancy is not a contraindication to Hepatitis B vaccination. In fact, pregnancy is an ideal time to target high-risk mothers since it is one of the few periods of time that young women routinely access preventive and prenatal healthcare. Despite these recommendations and their potential for decreasing a life-threatening disease, few centers routinely vaccinate such high-risk women, and no studies have been done to assess either the efficacy of vaccination in this group, or the feasibility of a routine vaccination protocol in such a population.
Therefore, the primary objective of this study is to determine the efficacy
of the Hepatitis B vaccine in high-risk pregnant women when given at an accelerated
vaccination schedule of 0, 1, and 4 months. The third vaccination is being offered
at 4 months rather than at 6 months after administration of the first vaccine.
The premise behind this accelerated scheme is that pregnant women often show
up for their first prenatal visit during or after the second trimester or deliver
early. By offering the third vaccination at an accelerated rate, more pregnant
women could potentially receive all three of their vaccinations before delivery.
Secondary objectives of the study include assessing the feasibility of implementing
a Hepatitis B vaccination protocol for high-risk pregnant women during prenatal
care and determining the variables influencing vaccine efficacy. Two hundred
pregnant women will be enrolled through the Parkland Medical Hospital OB Infectious
Disease Clinic.
2) "A Multi-Center, Randomized, Double-Masked, Comparator Study of the
Safety and Contraceptive Efficacy of C31G Vaginal Gel Compared to Conceptrol
Vaginal Gel" with Dr. Gretchen Stuart.
Approximately 85% of American women (52 million) between the ages of 15 and 44 are sexually active. With growing awareness of the risk of STDs, increasing numbers of women will require contraceptive methods that provide protection against STDs, in addition to providing basic contraceptive function. Condoms, both male and female, present problems of acceptability for the partners of many at-risk women, and thus, cannot be considered an effective contraceptive and STD preventive for many people. A spermicide that also has the ability to prevent transmission of STDs would be a major advance and of tremendous value to women worldwide. C31G is an effective spermicide with in vitro activity equal to that of nonoxynol-9. It has been found to be a broad-spectrum antibacterial agent, active against both gram-positive and gram-negative organisms, including chlamydia. It is also active against enveloped viruses, including HIV and HSV, giving it the potential to be used as a female-controlled protective method in the fight against global AIDS.
The study is a multi-center, randomized, double-blinded, controlled, Phase
III study of the contraceptive efficacy of repeated use of C31G vaginal gel
compared to the Conceptrol vaginal gel (nonoxynol-9) as the primary method of
contraception over six monthss of use. Secondary objectives include determining
the acceptability and safety of C31G vaginal gel; determining the incidence
of urinary tract infections, bacterial vaginosis, and yeast vaginitis following
the use of the gel; evaluating the incidence of lesions detected by colposcopy
in a subset of gel users; and measuring changes in vaginal microflora in another
subject of gel users. UT Southwestern is one of fourteen research centers enrolling
patients in this study and will be enrolling a total of 50 patients.
Katrina Willie
Baylor College of Medicine
Department of Internal Medicine
Mentor: Rebecca Gruchalla, M.D., Ph.D.
I will be joining the Allergy and Immunology Division of the Department of Internal
Medicine beginning July 2004. During the fellowship year, I will be developing
clinical investigation skills through participation in community-based participatory
research project entitled Community Leadership in Preventing Asthma - CLIP Asthma
and will design and implement an observational study looking at caregiver stress
and asthma morbidity. In addition, I will participate in specialty clinics,
research conferences and Allergy and Immunology teaching conferences and journal
clubs.
1). The CLIP Asthma project is three years in duration. I will be joining the
study in the year 03, the Community-Based Interpretation Phase which will consist
of two parts: 1) interpretation of study results and 2) dissemination and feedback.
In particular, I will look at the demographic data, indoor allergen skin test
sensitivity profiles and home environment exposure data of the study participants.
2). My mentor and I will design and implement an observational study looking
at the impact of caregiver stress on asthma morbidity in the child. A convenience
sample of caregivers of asthmatic children treated at a specialty clinic will
be surveyed using validated and reliable research instruments. The instruments
include the Cohen's Perceived Stress Scale and Juniper's Pediatric Caregivers
Quality of Life Questionnaire. Outcomes will include scores on the research
instruments and asthma morbidity data. Our primary hypothesis is that increased
caregiver stress and decreased caregiver quality of life will be related to
increased asthma morbidity in the child.
Brad Butcher
Duke University
Department of Internal Medicine
Mentor: Robert Collins, M.D., Ph.D.
Paul Hess
Emory University
Department of Internal Medicine
Mentor: Ronald Victor, M.D., Ph.D.
2003-2004 Fellows of the University of Texas
Southwestern Doris Duke
Clinical Research Fellowship Program for Medical Students
(UT Southwestern-Doris Duke-CRF)
Ten students will participate in the Doris DukeFellowship program at UT Southwestern:
Darin Bell
University of Texas Southwestern Medical Center
Department of Internal Medicine
Mentor: Richard Auchus M.D., Ph.D.
Darin is joining a project studying mechanisms of sodium-sensitive hypertension in African-Americans. We hypothesize that a significant fraction of low-renin hypertension in African-Americans is due to increased activity of the mineralocorticoid-ENaC (epithelial sodium channel) system. To test this hypothesis, we have designed a linked series of four protocols to examine patients with borderline and stage 1 hypertension.
Protocol #1 compares the BP response to amiloride (vs. placebo) in heterozygotes
for the ENaC (SCNN1B) mutation T594M and non-polymorphic controls. We will also
attempt to recruit and study the three homozygotes for this polymorphism that
we have identified in the Reynolds Database. BP response and reproducibility
will be determined using 24-hr ambulatory monitoring. Protocol #2 is similar
to protocol #1 and will be conducted as an overlapping effort, drawing in part
on subjects from the first protocol. Here, we will stratify according to their
BP responses to a mineralocorticoid receptor antagonist (either spironolactone
or eplerenone). Protocol #3 will be offered to poor responders from protocol
2, and will examine the response to combined amiloride and spironolactone/eplerenone.
Protocol #4 will characterize mineralocorticoid production in both poor responders
and brisk responders from protocols 1-3.
Brad Butcher
Duke University
Department of Internal Medicine
Mentor: Robert H. Collins, Jr., M.D.
General
Mr. Butcher will be involved in research projects involving hematopoietic cell
transplantation immunology. The main project will involve a clinical study of
a novel approach to graft-versus-host disease prevention. This will involve
extensive interaction with clinical researchers, translational scientists, and
patients. Additional work, time permitting, will include laying the groundwork
for subsequent studies of this approach and analyzing and preparing for publication
previously-collected clinical and laboratory data regarding immune reconstitution
in bone marrow transplant patients.
Specific
1. Clinical trial of selective allodepletion. This protocol has already been
approved by the IRB and is ready to begin soon. Mr. Butcher's participation
in this study will include screening patients for eligibility, bringing patients
on the study, and overseeing - along with the clinical research staff, study
nurse and translational scientist - all aspects of the clinical trial conduct.
Mr. Butcher will follow patients in the clinic, will interact with laboratory
personnel who are preparing selectively depleted cell populations and doing
studies of laboratory parameters, and will participate in scheduled meetings
involving all personnel participating in the project. Mr. Butcher will also
be involved in continuing regulatory issues with the IRB and the FDA.
2. Assuming early results from this study are promising, preparation of subsequent
studies will be indicated. This will involve literature research, extensive
discussion with team members, protocol writing, grant writing, and design of
the clinical follow-up plan.
3. Analysis of immune reconstitution in bone marrow transplant patients. Our
program has previously collected extensive clinical and laboratory data regarding
immune reconstitution after allogeneic stem cell transplantation. At this point,
these data require analysis and preparation for publication. Mr. Butcher will
be involved in this project and would be expected to be a primary author of
the paper.
Anthony Cordaro
The University of Texas Southwestern Medical Center
Department of Psychiatry
Mentors: Robin B. Jarrett, Ph.D.
Prophylactic Cognitive Therapy for Depression: NIMH R01 MH 58397
Anthony Cordaro will join a project funded by the National Institute of Mental Health to evaluate the comparative efficacy of preventive treatments for patients with recurrent major depressive disorder. Investigators in the Department of Psychiatry at the University of Texas Southwestern Medical Center (Principal Investigator: Robin B. Jarrett, Ph.D.) and at the University of Pittsburgh School of Medicine, Western Psychiatric Institute and Clinic (Principal Investigator: Michael Thase, M.D.) are conducting a randomized clinical trial evaluating the efficacy of and indications for 8 months of continuation phase cognitive therapy (C-CT), pharmacotherapy (fluoxetine; FLX), and pill placebo (PBO). Outpatients who presented with recurrent Major Depressive Disorder (MDD), have responded to acute phase cognitive therapy and continue to be at higher risk for relapse because of incomplete remission are randomized. "Higher risk" is defined by incomplete remission during the final weeks of acute phase CT, while "lower risk" is defined as a complete and stable remission (i.e., 7 consecutive Hamilton Rating Scale for Depression scores <7). This trial has great public health significance because it will help identify when cognitive therapy (CT) reduces the risk of relapse. These results will help clinicians to identify those patients at greatest risk for relapse who warrant longer courses of treatment. Such empirically-based decision roles could lower the cost of care by providing enough treatment for a depressive episode without either "over-treating" patients at lower risk or "under-treating" those patients at higher risk. This study is the first to evaluate continuation phase pharmacotherapy (FLX) after incomplete remission with acute phase CT. We hypothesize that both active treatments will reduce depressive relapse significantly more than pill placebo. Further, the pharmacotherapy group will permit tests of mode-specific vs. non-specific therapeutic activity. Lower risk patients will be followed for 8 months after acute phase CT. Dependent variables measure response, relapse, recurrence, remission, and recovery, as well as depressogenic attitudes, personality, social, and interpersonal functioning. Blind evaluations and survival analyses are planned.
The emphasis of his fellowship year is to acquire basic skills in psychiatric clinical research which he will continue to develop over an academic career. Anthony will participate in the following aspects of the randomized clinical trial.
Evaluation Clinic: The fellow will learn how to apply the inclusion and exclusion criteria used to develop a clinical sample. After training and observation, under supervision he will conduct telephone triage of interested patients. Anthony will observe clinic triage, full diagnostic clinic, and initial and longitudinal follow-up evaluation of patients. He will be exposed to evaluation of outcomes by clinical evaluators who are blind to condition assignment, as well the methods of establishing and monitoring diagnostic reliability and validity.
Empirically-Based Cognitive Therapy: The fellow will be exposed to state of the art methods for developing and maintaining the adherent and competent cognitive therapy conducted in acute and continuation phase formulations. He will observe weekly meetings in which videotaped therapy sessions are reviewed and rated to assess therapist competence.
Data Analyses: Anthony will collaborate with post doctoral investigators (Drs.
Patricia Borman and Mark Williams), with a biostatistician (Dr. Barbara Foster),
and the principal investigator (Dr. Robin Jarrett) in evaluating the psychometric
properties of the Cognitive Therapy Skills Scale-Patient Version. This scale
is designed to assess the extent to which the patient has learned and used compensatory
strategies hypothesized to partially mediate the preventive effects of cognitive
therapy.
Anthony will work with the team to design and conduct appropriate statistical
analyses, which evaluate the reliability and validity of this measure.
Designing Neuroimaging Feasibility Study: Anthony will collaborate with investigators in designing a neuroimaging study of patients with recurrent depression before and after exposure to acute phase cognitive therapy, consisting of 16-20 outpatient sessions conducted by experienced cognitive therapists. These patients will be evaluated, treated, and followed in the randomized trial described above (R01 MH 58397). Anthony will participate in investigative meetings to design a pilot study to be conducted by the research teams of Drs. Robin Jarrett and Dr. Carol Tamminga, who has agreed to be assist in the technical aspects of the project, after the study is designed. The team will be focused first on identifying neuroimaging correlates of response to acute phase cognitive therapy. Anthony will write a review of the literature on neuroimaging findings of patients treated with psychosocial interventions for mood and related disorders. He will work will Drs. Jarrett and Williams to develop a valid hypothesis regarding potential brain changes after effective acute phase cognitive therapy. He will help to develop a task to be conducted in the magnet and used to test the hypothesis. He will aid in writing and submitting an application for IRB approval to collect preliminary data from 5-6 patients. In addition to the literature review, the primary product from this effort will be a written research protocol which has been reviewed and consensual validated by the teams involved.
Paul Hess
Emory University
Department of Internal Medicine - Hypertension Division
Mentor: Ronald Victor, M.D.
I. Clinical Project
Can Barbers Cut Blood Pressure Too? A barber-run program to improve the awareness and treatment rates of hypertension in African-American men.
Introduction
The insurance industry in 1939 was the first to recognize that hypertension was a major risk factor for premature death. For African-American men, hypertension is more prevalent and constitutes a higher risk factor for cardiovascular morbidity and mortality than for any other demographic group. There are an estimated 125, 000 black men in Dallas County. Of these, 40% or 50,000 have high blood pressure before age 65, and 50% are unaware, 65% go untreated, and 85% do not have their blood pressure normalized. The result is needless death and disability from heart attack, stroke, and kidney failure. Because too few African-American men go to doctors, we need to go outside the traditional healthcare setting to solve this urgent public health problem. Building on the central role of the barbershop in the social life of black men and using a medical team in a pilot project ("Cut Your Pressure"), we recently showed that barbershops are effective places to improve detection and treatment of high blood pressure in African-American men. We now want to turn much of the program over to the barbers.
Specific Aims
The underlying hypothesis being tested is that barbers are uniquely positioned to make a real impact on early detection and treatment rates of hypertension in African-American men. Six (6) barbers have agreed to offer a free blood pressure check during every haircut, followed by distribution of educational materials and, if needed, appropriate referral to medical care. To begin to test this hypothesis, data will be collected from both automated blood pressure monitors and from a brief data form filled out at each haircut by each barber and compared for validation. Barbers will be reimbursed at a level commensurate with their productivity. The primary outcome measure will be the percentage of haircuts at which blood pressure is recorded by the barbers. Secondary outcome measures will be (1) the number of follow-up phone calls to our project nursing/medical staff by clients requesting further evaluation for an elevated blood pressure reading in the barber chair at screening and (2) the number of clients successfully referred to medical treatment by our staff. These descriptive statistics will serve as pilot (feasibility) data for a major grant submission to the NIH and the Reynolds Foundation in January of 2004.
II. Educational endeavors in patient-oriented research:
Paul is enrolled in an NIH-sponsored K30 grant aimed at achieving a certificate of proficiency in patient-oriented research. This fall, he is taking Introduction to Epidemiology and Introduction to the Principles and Practice of Clinical Research (a teleconference from the NIH) in addition to participating in other K30-sponsored seminars.
Paul is also gaining insight into the workings of patient-oriented research as a non-voting observer in the UTSW IRB and GCRC protocol approval meetings.
III. Continuing clinical education
When Paul does not have prior research responsibilities, he attends Medicine
Grand Rounds, Cardiology Grand Rounds, Hypertension Grand Rounds, and other
medicine and cardiology conferences. He will also see patients in hypertension
clinic.
Louise King
UT Southwestern
Mentor: Mark Drazner, M.D.
Project: Socioeconomic status, ethnicity, and heart failure
The first half of Louise's fellowship will center on the role of socioeconomic status (SES), ethnicity, and heart failure outcomes. The overall objective of the fellowship will be for Louise to develop epidemiological and statistical skills to begin a career related to health care policy, building upon her prior training (law degree) and career objectives. The fellowship will consist of research projects, didactics, frequent meetings with Dr. Mark Drazner who will serve as her mentor, and enhancement of clinical care skills through weekly participation in the Parkland Memorial Hospital Congestive Heart Failure Clinic.
Research projects for Part I of fellowship:
a. Health insurance and cardiac transplantation. Presently patients without
health insurance are not eligible for cardiac transplantation. This project
will explore the ethics and legal aspects of the status quo. Additionally, in
collaboration with Dr. Laura Siminoff at Case Western, we will determine how
often donors do not have health insurance.
b. Comparing outcomes in a private practice vs. an urban public CHF clinic:
It is not yet clear whether African Americans have worse outcomes than Caucasians
when they develop CHF. Issues related to access to care have confounded most
prior such analyses. At UTSW, there are 2 separate CHF clinics, one with private
patients at St. Paul University Hospital and 1 at Parkland Memorial Hospital.
The same physicians run both clinics. This project will determine whether patients
in these 2 clinics have different outcomes, to address the question of ethnic
disparity and outcomes in CHF. Baseline characteristics will be compared to
determine if late presentation is a factor for outcomes.
c. Outcomes of Medicaid recipients following cardiac transplantation: Using
data from the UTSW cardiac transplant program, outcomes of patients with Medicaid
will be compared to patients with other health insurance.
d. Cardiac transplant clinic - Friday 8AM-9AM (for project 1a. above).
Additional research projects for the later portions of the fellowship have yet to be finalized, but will likely evolve from and employ data from the Dallas Heart Project.
Hao Lo
Duke University Medical Center
Department of Radiology
Mentor: Ron Peshock, M.D.
Study of abdominal aortic atherosclerosis using magnetic resonance imaging
Fundamental Problem and Importance:
Atherosclerotic cardiovascular disease continues to be a major cause of morbidity
and mortality in the United States, resulting in acute cardiovascular events
such as stroke, myocardial infarction and aortic aneurysm. Autopsy data has
shown that the atherosclerotic process differentially affects certain areas
of the vasculature, including the coronary arteries and the abdominal aorta.
Development of an accurate and sensitive noninvasive assay for assessment of
disease progression remains one goal of current research efforts. Specifically,
estimation of disease extent and atherosclerotic plaque burden are particularly
important, as these factors have been correlated to probability of the above-mentioned
acute cardiovascular events. In previous studies, cardiovascular magnetic resonance
imaging (MRI) has successfully quantified subclinical aortic atherosclerosis
in humans3, and atherosclerotic plaque content in both humans4 and animals5,6.
However, these studies have involved relatively small numbers of subjects without
substantial ethnic diversity3. Thus, it is not know if the results of these
studies can be applied to the population as a whole. In the current study, we
seek to study abdominal aortic atherosclerosis via MRI as a marker for overall
atherosclerotic disease extent in the participants in the Dallas Heart Study
(DHS). This population-based sample, supported by the Donald W. Reynolds Foundation,
has been carefully designed to reflect the ethnic composition of Dallas County.
In addition, it is unique for its large proportion of African-Americans subjects
and is being used to investigate the disparity in atherosclerosis-associated
morbidity and mortality between different ethnic populations. As part of the
DHS, the participants have previously received phenotyping via multiple biochemical
and imaging modalities, including electron-beam computed tomography for assessment
of coronary artery calcium and cardiovascular MRI.
Hypotheses:
1. Assessment and quantification of abdominal aortic atherosclerosis using MRI
has low intra-observer, inter-observer and inter-study variability.
2. Analysis of abdominal aortic MRI obtained in the roughly 3,000 DHS participants
will demonstrate that the African-American population has increased atherosclerotic
burden as compared to other ethnic group populations.
3. The prevalence of atherosclerotic disease as measured by abdominal aortic
MRI is higher in the African-American population compared to the entire sample
population.
4. Abdominal aortic MRI exhibits a higher sensitivity than coronary artery calcium
score for the detection of atherosclerosis.
5. Coronary calcium score underestimates the true disease burden.
Experiments:
1. Using a representative sample of the total DHS population, abdominal aortic
images will be analyzed once and again 1 week later to determine intra-observer
variability. The same images will be analyzed by another researcher using the
same method to determine inter-observer variability. The same participants will
be contracted to return for repeat studies to determine inter-study variability.
The images will be reviewed with the readers blinded to their previous and others
readings. These data will then be subjected to statistical analysis.
2. Criteria for acceptance or rejection of MRI images, based on observations
from the representative sample, will be determined prior to analyzing the entire
DHS data set. Then the entire image set will be analyzed for amount of abdominal
aortic atherosclerosis and total disease burden quantified. Statistical comparison
of the disease burden in the African-American group to the non-African-American
group will be undertaken.
3. The prevalence of atherosclerotic disease in the African-American population
will be compared to that of the entire DHS population using the Sudan program,
which corrects for issues of sampling frequency. Prevalence will be pre-defined
by a threshold of disease observed in the abdominal aorta.
4. The estimation of total disease burden observed by MRI will be statistically
compared to the estimation by coronary calcium score.
Methods of Analysis:
Statistical methods for the analysis of data obtained from the experiments include:
1. F statistic and ANOVA for the analysis of intra-observer, inter-observer
and inter-study variability.
2. Sudan program for determination of prevalence of disease in the population,
in the setting of non-conventional sampling frequencies.
3. Chi-squared analysis for the comparison of coronary calcium score to MRI
results as categorical variables (presence vs. absence of disease).
4. Linear regression analysis and the Bland-Altman method7 for determining the
concordance between disease burden via coronary artery calcium score and disease
burden via MRI, evaluated as continuous variables.
Rajiv Shah
University of Texas Southwestern Medical Center
Department of Radiology
Mentor: Ron Peshock, M.D.
Arterial stiffness has been shown to be an important determinant of pulse pressure,
LV load, and coronary perfusion pressure. Furthermore, pulse pressure has been
demonstrated as an important parameter, along with systolic blood pressure,
in understanding cardiovascular events. MRI has been shown, from previous work,
to be a valuable non-invasive tool for assessing changes within the aorta and
for determining pulse wave velocities. We have developed successful methodology
to extract both parameters from standard MR scans. Using MRI to access aortic
compliance and pulse wave velocity within the cohort of the Dallas Heart Study,
we will characterize which ranges of stiffness and velocity represent a "normal"
phenotype vs. a diseased hypertensive state. In addition, we will study how
possible confounding variables (ethnicity, social habits, etc.) affect the parameters
of velocity and stiffness to see if there is a strong link between phenotypic
states and compositional changes within aortic walls.
Robert Silge
University of Texas Southwestern Medical Center
Department of Internal Medicine
Mentor: Rebecca S. Gruchalla, M.D., Ph.D.
Robert Silge will be joining the Division of Allergy and Immunology in the Department of Internal Medicine beginning July 1, 2003. During the fellowship year, Mr. Silge will be developing basic clinical research skills through his participation in a community-based participatory research project entitled, " Community Leadership in Preventing Asthma - CLIP Asthma." In addition to acquiring research skills, the program that we have developed for him also includes attending specialty clinics, research conferences, clinical Allergy and Immunology conferences and journal clubs.
Summary of fellow's research experience:
Much research has focused on the role of indoor allergens in asthma and studies have demonstrated that allergens in the indoor home environment contribute greatly to asthma-associated morbidity. However, few studies have focused on the second most important environment for children, their schools. In our project, entitled, "Community Leadership in Preventing Asthma - CLIP Asthma, we are evaluating the relationship between school environments and asthma-associated morbidity using a community-based participatory approach. Our overall hypotheses are: 1) asthma prevalence will be higher in schools with high allergen levels, and 2) children who attend schools with high indoor allergen levels will have more asthma-associated morbidity than asthmatic children who attend schools with low indoor allergen levels. In order to accomplish our goals, a partnership has been established with leaders in the faith-health community. These individuals are helping to facilitate our interactions with the community.
For this study, the Dallas Independent School District (DISD) provided us with a list of all the elementary schools in the DISD catchment area and also a rough estimate of the prevalence of asthma in each of these schools. From this list, dust samples from the 10 elementary schools that were noted to have the highest prevalence of asthma were collected and analyzed. Of these schools, one school was found to have very high indoor allergen levels while the others had very low levels. In the next phase of the project, we will evaluate the children in the high-allergen school and one low-allergen school to determine if asthma prevalence and asthma associated morbidity is different between the two schools.
The CLIP Asthma project is three years in duration. Mr. Silge will be joining us in year 02, the year of the actual study. During the first year of the study we: 1) finalized the study protocol; 2) selected the schools for evaluation; 3) finalized the morbidity measures to be assessed; 4) developed the data collection forms; and 5) initiated the development of the database.
In year 02, the study team will be administering an asthma screening survey to the caretakers of the two selected schools. Children who have known asthma as well as those who have symptoms consistent with asthma (wheezing, coughing, chest tightness) will be invited to undergo skin testing. Those children who are skin test positive to one or more relevant indoor allergen (dust mite, cockroach, cat, dog, rat, mouse) will be invited to participate. Three groups of children will be followed over the course of the school year: 1) children with known asthma, 2) children who have symptoms consistent with asthma and in whom asthma is diagnosed by the by the study investigators, and 3) children who have asthma-like symptoms but who do not fulfill all of the criteria required for having asthma. Symptoms, medication use and health care utilization will be evaluated at 2-month intervals in all three groups. In addition to evaluating the children, home and school evaluations will be performed. During these evaluations, dust samples will be collected and allergen levels analyzed.
Mr. Silge will be an important member of the study team. He will not only
participate in administering the screening questionnaires, but also he will
participate in the home and school allergen evaluations as well as in the 2-month
morbidity assessments of the children who participate. In addition to these
experiences, Mr. Silge will learn how to enter data into a database and he will
learn basic knowledge about data analysis from the study investigators and the
statistician working with the team. It is anticipated that Mr. Silge will prepare
and present an abstract for the 2005 annual meeting of the American Academy
of Allergy, Asthma and Immunology. It is also anticipated that he will author
at least one peer-reviewed journal article.
Kelly Tierney
Drexel University
Project title: Mechanisms of Lipodystrophy in HIV-Infected Patients
Mentor: Abhimanyu Garg, M.D.
This is an NIH funded grant intending to characterize the metabolic abnormalities and changes in body fat distribution related to protease inhibitor therapy.
Human immunodeficiency virus (HIV) infection is a major global health problem.
Recently, combination therapy including HIV-1 protease inhibitors (PIs) has
dramatically improved the long-term survival of HIV (+) patients. However, such
therapy is associated with a lipodystrophy syndrome characterized by marked
loss of subcutaneous (sc) fat from the face and extremities but excess of sc
fat around the neck, dorsocervical region and trunk. Such patients have increased
propensity to insulin resistance, diabetes mellitus and dyslipidemia. The metabolic
and molecular basis of lipodystrophy syndrome in HIV-infected patients is not
known. Whether besides PIs, other antiretroviral drugs, HIV infection and reduction
in viral load contribute to the development of lipodystrophy syndrome is not
clear. The project therefore has the following aims: 1) to characterize metabolic
abnormalities and changes in body fat distribution, 2) to develop objective
criteria for defining the syndrome and to ascertain prognostic indicators and
3) to elucidate the molecular basis of the lipodystrophy syndrome in HIV-infected
patients. To accomplish these aims, we will conduct a 2-year long prospective,
randomized, double blind, placebo-controlled study in 200 asymptomatic HIV (+)
patients to compare two equally effective antiretroviral regimens, one with
and the other without a PI. We will study body fat distribution by anthropometry
and magnetic resonance imaging and will measure insulin sensitivity (in a subset
of patients), plasma lipoproteins, glucose tolerance and other metabolic variables.
We will study expression of an array of adipocyte specific proteins/transcription
factors involved in adipocyte differentiation, insulin action and lipoprotein
metabolism in fat biopsy samples obtained before and after institution of therapy.
Identification of the metabolic and molecular basis of lipodystrophy syndrome
in HIV (+) patients may lead to better understanding of role of adipocyte-specific
genes in insulin action and body fat distribution and may lead to discovery
of other antiretroviral drugs that do not cause the lipodystrophy syndrome.
Additionally, the study may prove effectiveness and reduced toxicity of alternative
antiretroviral regimens without a PI.
Kenneth Youens
University of Texas Southwestern Medical Center
Department of Psychiatry
Mentor: Carol Tamminga, M.D.
Human brain imaging studies of people with schizophrenia demonstrate replicable, task-specific regional cerebral blood flow (rCBF) pattern abnormalities localized to the anterior cingulate gyrus and middle frontal cortex. The abnormalities in frontal rCBF are thought to be associated with the cognitive symptoms of schizophrenia. These symptoms include defects in attention, learning, short-term memory, and executive function, and are a persistent, core feature of this illness. Traditional antipsychotics like haloperidol fail to demonstrate improvements in cognitive domains and may actually worsen cognition. Some of the newer serotonin-dopamine antagonists have shown some benefits in certain cognitive domains, but improvements have been modest. These cognitive deficits are strongly linked to functional outcomes such as social competence and the capacity for work, so there is a need for new treatments for these symptoms.
There is evidence that cognitive remediation strategies such as instruction, practice, and reinforcement can improve performance on various tests of cognitive function. Hypothetically, drug treatment could augment the remediation response. We will study the effects of atomoxetine, a relatively selective noradrenergic reuptake inhibitor that purportedly increases blood flow to critical frontal structures, so the frontal cortex can have a better chance to regain active function in the context of cognitive remediation training. In addition to various conventional neuropsychological tests, we plan to use quantitative measurement of rCBF deficits as a biological surrogate to assess the impact of our interventions.
Kenny will participate in all aspects of this study, including patient recruitment and evaluation, observation of neuropsychological testing, cognitive rehabilitation, and acquisition and interpretation of functional MRI rCBF data. There will be a special emphasis on evaluation of brain function using functional imaging approaches and cognitive measurements. In addition to this main project, he will participate in protocol design and grant writing for additional new projects in what will be a thorough introduction to the techniques of clinical research in schizophrenia.
Below are listings of the students that have participated in the Doris Duke program at UT Southwestern in past years:
2002-2003 Fellows of the University of Texas
Southwestern Doris Duke
Clinical Research Fellowship Program for Medical Students
(UT Southwestern-Doris Duke-CRF)
Alisha Allen, University of Missouri-Columbia
Department of Hematology/Oncology
Mentor: Carlos Becerra and Noel Williams
Alisha Allen will be joining the Simmons Cancer Center for her Doris Duke Fellowship beginning July 24, 2002. Her efforts will be focused on developing basic laboratory skills in the area of oncology, specifically gastrointestinal malignancies. Specifically, she will work to determine the relative sensitivity or resistance to CPT-11, 5-FU, and Oxaliplatin for several well-characterized human colon tumor cell lines as well as for several additional uncharacterized lines. Once the patterns of sensitivity and resistance are established for each cell line, the cells will be injected subcutaneously into nude mice. The mice will then be treated with individual drugs or left as controls. The pattern of gene expression in the human tumors will then be monitored by cDNA microarray analysis, comparing treated to untreated tumors. These analyses will be performed for both sensitive and resistant cell lines. The changes in gene expression noted for sensitive versus resistant cell lines will then be compared. It is anticipated the expression patterns of a set of genes will be identified that correlates with resistance to a particular drug. In addition, Alisha will also spend time interacting with patients and physicians involved in clinical trials and will work with Dr. Becerra to write a clinical trial protocol over the course of the year. The goal for her fellowship is to develop basic skills in translational and clinical research that she will be able to build upon during an academic career in medicine.
Dan Martin, University of Texas Southwestern Medical Center
Reynolds Cardiovascular Research Department
Mentors: Richard Auchus and Ronald Victor
Dan Martin joined a project funded by the Reynolds Foundation to determine the genetic basis of hypertension in African-Americans. The emphasis for the year is for Dan to acquire hands-on experience with all phases of conducting clinical investigation: from the inception of the hypothesis and formulation of specific questions to the writing of protocol, data, acquisition and analysis, to the composition of manuscripts and abstracts derived from the research. This experience is designed to afford an exposure to all aspects of clinical research and to foster Dan's enthusiasm for a career in academic medicine.
We hypothesize that a significant fraction of low-renin hypotension in African-Americans
is due to increased activity of the mineralocorticoid-ENaC (epithelial sodium
channel) system. To test this hypothesis, we have designed a linked series of
4 protocols. Protocol #1 will be a double blinded placebo controlled study designed
to determine if the 5% of individuals who have the T594M polymorphism at the
ENaC are more responsive to the ENaC antagonist amiloride than controls. Protocol
#2 is similar to protocol #1 except that the study medication will be eplerenone
(a mineralocorticoid antagonist similar to spironolactone). Protocol #3 will
be used to find ~10 subjects who's BP does not respond to both eplerenone and
amiloride together. From protocols 1-3, we will identify subgroups of patients
who respond well to amiloride, eplerenone, or neither drug. We will then exhaustively
characterize their mineralocorticoid production and action in protocol 4, identifying
biochemical markers that will ultimately facilitate an investigation of the
genetic basis of hypertension in these subgroups.
Kristie Moss, University of Texas Southwestern Medical Center
Department of Obstetrics and Gynecology
Mentor: Kenneth Leveno and Jeanne Sheffield
Kristie Moss will be joining the Division of Maternal-Fetal Medicine for her Doris Duke Fellowship beginning July 1, 2002. The emphasis for her year is to develop basic skills in clinical research that she will be able to build onto during an academic career. Toward this end, we have designed a program for her, taking into account the strengths of the Division of Maternal-Fetal Medicine. She will participate in various components of three different clinical trials.
A. Diabetes in Pregnancy: A large multicenter funded by the Maternal-Fetal Medicine Unit Network of the NICHD will begin enrollment this year. This is a comprehensive study of gestational diabetes which will help define new definitions and treatment guidelines. The individual sites are in the process of learning the protocol and setting up the framework for the trial in the clinical setting. Kristie will be a part of the implementation of this protocol, obtaining an understanding of what is required to initiate and manage a large clinical trial.
B. First Trimester Bleeding in Pregnancy: Bleeding during the first trimester of pregnancy is a common problem; however, evaluation and management of this problem is not well defined. An obstetric clinic has been designated to follow these women, allowing standardization of their care. The initial phase of this study will be to characterize the problem. Kristie will be involved in defining important parameters to study, and then designing tools and a database to collect the pertinent data. Once collected and analyzed, this data will be used to design management protocols for this large cohort of women.
C. Hepatitis B Vaccination in High Risk Women: Though universally recommended,
hepatitis B vaccination of high risk women is not usually performed during pregnancy.
Fear of untoward fetal effects prevents most physicians from taking advantage
of a time in a woman's life when she seeks medical care. The hepatitis B vaccine
has been found to be safe in pregnancy. We have an ongoing clinical trial vaccinating
high risk pregnant women followed in the Infectious Disease OB Clinic. Kristie
will manage this trial with a plan to complete enrollment by the end of her
one-year fellowship.
Gunjan Parikh , Texas A & M University System Health Science
Center College of Medicine
Department of Hematology/Oncology
Mentor: John Minna and Adi Gazdar
Simian virus 40 (SV40) has previously been associated with a variety of human
tumors, including mesothelioma and osteosarcoma, and most recently in lymphomas
and brain tumors. SV40 belongs to the same polyomavirus family as JC and BK
viruses, which have a high prevalence in humans and often cause, in immuno-compromised
patients, progressive multifocal leukoencephalopathy (PML) and cystitis, respectively.
SV40 is a potent oncogenic DNA virus whose genome encodes tumor antigens (Tag).
The large Tag gene product is a protein, essential in transforming host cells,
that binds to and inactivates specific host cell proteins such as the key tumor
suppressor gene-p53.
SV40 was first linked to human cancers after researchers had discovered that millions of vials of polio vaccine, contaminated with SV40, infected individuals in the United States between 1953 and 1963. Until recently, these researchers have been met with skepticism. Whether coincidence or not, rates of mesotheliomas, lymphomas, and brain tumors have all dramatically gone up in the last 30 years.
Gunjan will involve himself in a project that will specifically focus on further extending the current knowledge about the presence of SV40 in adult and pediatric brain tumors and CNS lymphomas. Importantly, in addition, Gunjan will determine the status of methylation of different genetic markers, most importantly, RASSF1A promoter region of the RASSF1 gene. Very little information is available regarding the aberrant methylation profile of brain tumors. Promoter methylation is believed to be associated with silencing of the tumor suppressor genes.
RASSF1 is a recently discovered important putative tumor suppressor gene that
has an important role in controlling cell proliferation during the cell cycle.
Studies have shown in cancers such as lung cancarcinomas that aberrant hypermethylation
of RASSF1A is associated with malignant transformation and poor prognosis. As
in previous studies done on mesotheliomas in Dr. Adi Gazdar's lab, we will look
for supporting evidence for the linking role of SV40 and RASSF1 methylation
in the pathogenesis of different brain cancers. Finally, the results will be
correlated with the histological pattern, stage, and survival rates of the brain
tumor cases.
Travis Petricek, University of Texas Houston Medical School
Department of Human Nutrition
Mentor: Abhimanyu Garg
Project Title: Mechanisms of Lipodystrophy in HIV-infected patients
This is a NIH-funded project. Most efforts will be directed toward recruitment and data collection for a two year trial intended to characterize metabolic abnormalities and changes in body fat distribution and to develop objective criteria for defining the lipodystrophy syndrome in HIV-infected patients. We will also investigate the molecular basis of the lipodystrophy syndrome in HIV-infected patients. In this trial, untreated HIV-infected patients are randomly assigned to one of the two treatment regimens; one with nelfinavir, a protease inhibitor (PI)- containing HAART (highly active antiretroviral therapy) and the second with efavirenz, a non-PI- containing HAART. Patients will be closely evaluated through out the study for the metabolic parameters and body shape changes suggestive of lipodystrophy associated with HIV-infection. Approximately 200 HIV-infected patients, age 18-70 years, will participate in this study. Patients are required to have CD4+ lymphocyte (T-cell) counts more than 100 cells/mm3 and no previous antiretroviral therapy. Evaluation will include skin-fold measurements, extensive metabolic testing, full body MRI, full body DEXA and biopsies of muscle and fat. These studies will be completed over a two year period during 9 periodic outpatient and inpatient visits.
Molecular studies will include examining the expression of several genes in the fat and muscle tissue collected from the biopsies of these patients before and after therapy. Certain candidate genes, involved in adipocyte differentiation, adipocyte biology and apoptosis and those known to be defective in inherited lipodystrophies will be analyzed using quantitative PCR.
He will also participate in the ongoing evaluation of HIV-infected patients with lipodystrophies and comparison of their clinical and metabolic characteristics to control HIV-infected patients without lipodystrophies.
Activities
Over the course of the year, Travis intends to audit courses in hospital economics
and biostatistics. He will also be attending weekly GCRC conferences, Center
for Human Nutrition Grand Rounds twice a month and weekly Medicine Grand Rounds
on a regular basis.
Jason Reingold, Emory University School of Medicine
Reynolds Cardiovascular Research Department
Mentors: Ronald Victor and Lidia S Szczepaniak
I. Clinical Project:
Evaluation of myocardial triglyceride by 1H NMR in the Reynold's Cohort
Introduction:
As the United States has become the fattest nation in the world, obesity is
an increasingly important cause of cardiovascular morbidity and mortality. The
traditional view suggests that obesity indirectly predisposes to heart disease
by increasing the established cardiovascular risk factors such as LDL cholesterol.
In contrast, an emerging body of basic research pioneered by Roger Unger's lab
advances the novel theory that obesity constitutes a direct risk cardiac factor
by promoting ectopic deposition of triglyceride in cardiac myocytes, a process
termed "cardiac steatosis." Under this theory, accumulation of intracellular
triglyceride activates abnormal signaling pathways that culminate in myocyte
hypertrophy and apoptosis, recognized clinically as left ventricular hypertrophy
and systolic dysfunction. The ability to precisely quantify myocardial triglyceride
content in the intact human heart with1H-NMR, a technique recently developed
at UT southwestern by Dr. Lidia Szczepaniak, provides the opportunity to begin
to translate this basic research to the clinical setting.
Purpose:
The first step in this translational human research, and the aim of this initial
phase in our research, is to determine the acute effects of fasting and feeding
on the measurement of myocardial and hepatic triglyceride. We need to know whether
our subjects need to be fasted for all subsequent studies. An additional aim
is to address the same question with regard to hepatic triglyceride by NMR,
as a large amount of data already has been collected as part of the Reynolds
clinic visit.
Specific Aims
A. Myocardial Triglyceride.
Determine if:
1. In healthy lean individuals, a high fat meal normally has little or no effect
on myocardial triglyceride content by H1- NMR. We hypothesize that in lean individuals
myocardial triglyercide content normally is a tightly regulated, resulting in
very low levels that are largely unaffected by the transient increase in plasma
free fatty acids after a high fat meal.
2. In otherwise healthy obese individuals, fasting myocardial triglyceride content is increased and a high fat meal may cause an acute further increase. The animal data suggest that obesity leads to dysregulation of myocardial triglyceride content by impairing beta-oxidation of fatty acids, leading to cardiac steatosis. Thus, we need to know whether this measurement is insensitive to a high fat meal over a large range of BMIs.
B. Hepatic Triglyceride.
Determine if:
1. Hepatic triglyceride measurement by 1H NMR acutely fluctuates in response
to a high fat meal. For validation purposes, we will study Reynolds clinic subjects
with a wide range of values for hepatic triglyceride (on the initial study)
and BMIs.
II. Educational endeavors in patient oriented research:
Jason is currently enrolled in an NIH sponsored K-30 grant aimed at achieving a certificate of proficiency in patient orientated research. This f all, he will be taking medical epidemiology and biostatistics in addition to participating in other K-30 sponsored seminars.
Jason is also gaining first hand experience into the art of patient oriented research as a non-voting observer in the UTSW IRB and GCRC protocol approval meetings.
III. Continuing clinical education
When appropiate, Jason will participate in our hypertension clinic in addition to other cardiology clinics at his discretion. Additionally, he actively attends medicine, cardiology, and hypertension grand rounds and daily lunch- time talks when he does not have prior research responsibilities.
Jason Spaulding, University of Texas Southwestern Medical Center
Department of Pediatrics
Mentor: Gail Tomlinson, M.D.,Ph.D. and Naomi Winick, M.D.
The overall emphasis of his training program will be to provide exposure to the translational research process. His specific project will be to develop and carry out a protocol for the follow-up of patients with von-Hippel Lindau Syndrome (VHL), with specific attention to the development of serum markers for the disease. In addition, Jason will be performing an analysis of a clinical trial involving childhood leukemia under the mentorship of Dr. Naomi Winick. Together, these projects will provide him with an understanding of the clinical and translational research process.
The VHL project will address the hypothesis that proteins regulated by the
VHL protein which contribute to the proliferation of vascular tumors may be
detectable in the serum, either prior to or during tumor development. During
the past two years a number of faculty on campus who are interested in VonHippel
Lindau Syndrome have been identified with the intent of eventually developing
clinical research protocols relevant to this disease. We have accrued a total
of seven families with VHL, included two pedigrees, which have been extended
to include multiple members. The registry of families is maintained by the Clinical
Cancer Genetics office in the Simmons Cancer Center. Genetic testing is available
and is able to determine mutations in almost all affected families. Thus it
is possible to discern mutation carriers from non-carriers in young asymptomatic
family members. This project will compare serum markers of VEGF, VEGF receptors,
and other hypoxia regulated proteins in mutation carriers and non-carriers in
Von Hippel Lindau families.
Paul Tannous, University of Iowa
Department of Cardiology
Mentor: Joseph Hill
2001-2002 Fellows of the University of Texas
Southwestern Doris Duke Clinical Research Fellowship Program for Medical Students
(UT Southwestern-Doris Duke-CRF)
Five students were selected to complete their fellowships at UT Southwestern:
Warren Dinges, UT Southwestern Medical Center
Brijen Shah, Brown University Medical School
Rodney Stuart, UT Southwestern Medical Center
Thomas Sims, Medical University of South Carolina
Mahesh Karandikar, UT Southwestern Medical Center
Brief summaries of the research being conducted by the five fellows are listed
below.
Student: Warren Dinges
Medical School: UT Southwestern
Year Completed: 3rd
Mentor: Abhimanyu Garg
Department: Center for Human Nutrition
Project name: Mechanisms of lipodystrophy in HIV infected patients
A lipodystrophy syndrome in HIV-infected patients was first reported in 1997.
This syndrome, which consisted of body morphology changes and metabolic abnormalities,
has been most strongly associated with the protease inhibitor portion of HAART
therapy. Under a grant from NIH, Dr. Abhimanyu Garg with co-investigators will
endeavor to elucidate the mechanisms of LDHIV.
Specifically, work during the Doris Duke Fellowship will be directed towards
the initial enrollment of this study and the development of a portion of the
laboratory assessment on these patients. Specifically, I will be developing
a quantitative real-time RT-PCR mRNA expression assay of 30-50 human genes for
fat and muscle biopsies of the patients. This includes sample handling and extraction,
gene selection, method design, primer/probe selection, and initial method validation.
Finally, I will also be involved in the enrollment of the initial patients during
the first year of the four-year study. This will include screening appointments,
inpatient evaluations, and outpatient study visits.
Summary of proposed work:
I am spending my Doris Duke Fellowship year in the Center for Nutrition working
on the metabolic component of the Reynolds Center Project/Dallas Heart Disease
Prevention Study. My work focuses on body fat and its association with a variety
of heart disease parameters. The first three months of my DDCRF will be spent
analyzing the DEXA scan data and its relationship to body mass index, lipoprotein
levels, and other plasma markers. The goal of this work is to understand the
associations between body fat quantity and distribution and its relationship
to key heart disease parameters. In addition, I will work with my mentors on
some methodological questions such as the measurement of muscle mass and its
relationship to the new DEXA technology. The second portion of my time will
be spent being involved in protocols which will bring Reynolds subjects into
the GCRC for a variety of metabolic studies. This plan for my fellowship year
will give me exposure to a variety of techniques in patient oriented research
while giving me an in depth look at how body fat and lipids plays a role in
heart disease.
Student: Rodney Stuart
Medical School: UT Southwestern
Year Completed: 2nd
Mentor: Michael Racke
Department: Neurology
Project name: T cell activation requirements in autoimmune demyelination
My project deals with the inhibitory receptor CTLA4 found on the T-cell. It
has been observed by other investigators that a point mutation where an adenine
is replaced with a guanine in the leader sequence of the CTLA4 genome correlates
with an increased incidence of autoimmune disease such at Grave's disease, rheumatoid
arthritis, and multiple sclerosis. Currently, I am screening an array of multiple
sclerosis patients for the point mutation and associating this mutation with
1) their MHC haplotype and 2) whether they have the relapsing remitting or progressive
form of the disease. The aim of the project is to observe how this mutation
may contribute to the exacerbation of multiple sclerosis.