Medical Student Research Fellowship for Summer 2003

Mentor: Charles Rosenfeld
Department: Pediatrics
Room number: E3.600
Mail Code: 9063
Phone number: 83903
E-mail: crosen@mednet.swmed.edu
Project title:
Characterization of the neutrophilic responses to nosocomial infections in the NICU

Human subjects IRB approved project number (where applicable): N/A

Animal subjects IRB approved project number (where applicable): N/A

Project Type (patient-based research, animal-based research, or basic research; this characterization is only to permit a general classification for grouping similar types of projects)

Brief Description of Project:
Neonatal sepsis occurs as early-onset disease, i.e., within 72h after birth and is acquired prior to or at the time of birth, or late-onset, i.e., occurring after 4-7d of life and acquired from the environment. We characterized and defined the normal reference ranges for neutrophilic values during the first month after birth and reported that evaluation of the absolute neutrophilic values in either early-or late-onset sepsis had high specificity. Thus in the absence of sepsis, as defined by negative blood cultures, the likelihood of having abnormal neutrophilic parameters in serial white blood cell counts obtained over 24h is less than 5%. Moreover, the sensitivity of this test in the presence of positive blood cultures is >80%. These observations have been confirmed by other investigators, including ourselves. The flora in neonatal intensive care units (NICU) has changed as have the pathogens responsible for late-onset or nosocomial infection. During the past 5 yrs, coagulase-negative staphylococcus, previously considered contaminants, have become a major cause of nosocomial neonatal sepsis, especially in the presence of a central venous catheter. In several recent cases it appeared that these organisms may not stimulate neutrophilic responses previously seen with sepsis, i.e., all neutrophilic values remained within the normal reference ranges despite 2 or more positive blood cultures. Thus the purpose of this project is to utilize the Neonatal Computerized Database in the Division of Neonatal-Perinatal Medicine to identify all cases of nosocomial sepsis occurring in the Parkland Memorial Hospital NICU during the past 5 yrs, identify the pathogenic organism from the database, establish a data collection form to include clinical variables and the serial neutrophilic values that were obtained at the onset of disease. This will permit us to characterize the neutrophilic responses to sepsis caused by several organisms. If neutrophilic responses to coagulase negative staphylococcus are different, this will be an important diagnostic observation and should lead to subsequent studies designed to understand what is responsible.

Previous Research Activities or Publications with Medical Students:
Starling Corbett, 1990: Corbett SS, Rosenfeld CR, Laptook AR, Risser R, Maravilla AM, Dowling S, and Lasky RE. Intraobserver and interobserver reliability in the assessment of the cranial ultrasound in very-low-birth-weight infants. Early Human Develop 27:9-17, 1991.
Jennifer Chern, 1993: Chern J, Kamm KE, and Rosenfeld CR. Smooth muscle myosin heavy chain isoforms are developmentally regulated in male fetal and neonatal sheep. Pediatr Res 38:697-703,1995.
Amy Becker, 1997: Studies of outcome in very-low-birth-weight infants. No publication.

Return to UT Southwestern Homepage

Return to Student Research Projects Index