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Biomedical subjects

Helen M Baron

Publications and source records attributed to Helen M Baron.

3 recordsLinked to original sources
PubMed2006

The role of Staphylococcus aureus adhesins in the pathogenesis of ventricular assist device-related infections.

Ventricular assist devices (VADs) are an important form of therapy for end-stage congestive heart failure. However, infection of the VAD, which is often caused by Staphylococcus aureus, poses a major threat to survival. Using a novel in vitro binding assay with VAD membranes and a heterologous lactococcal system of expression, we identify 3 S. aureus proteins--clumping factor A (ClfA) and fibronectin binding proteins A and B (FnBPA and FnBPB) as the main factors involved in adherence to VAD polyurethane membranes. Adherence is greatly diminished by long implantation times, reflecting a change in topological features of the VAD membrane, and is primarily mediated by the FnBPA domains in the staphylococcal proteins. We also compare the adherence of S. aureus mutant strains and show that other staphylococcal components appear to be involved in adherence to VAD membranes. Finally, we demonstrate that ClfA, FnBPA, and FnBPB mediate bacterial infection of implanted murine intra-aortic polyurethane patches.

Adhesins, Bacterial↗
PubMed2005

The economic implications of noninvasive molecular testing for cardiac allograft rejection.

Endomyocardial biopsy is the mainstay for monitoring cardiac allograft rejection. A noninvasive strategy--peripheral blood gene expression profiling of circulating leukocytes--is an alternative with proven benefits, but unclear economic implications. Financial data were obtained from five cardiac transplant centers. An economic evaluation was conducted to compare the costs of outpatient biopsy with those of a noninvasive approach to monitoring cardiac allograft rejection. Hospital outpatient biopsy costs averaged 3297 US dollars, excluding reimbursement for professional fees. Costs to Medicare and private payers averaged 3581 US dollars and 4140 US dollars, respectively. A noninvasive monitoring test can reduce biopsy utilization. The savings to health care payers in the United States can be conservatively estimated at approximately 12.0 million US dollars annually. Molecular testing using gene expression profiling of peripheral circulating leukocytes is a new technology that offers physicians a noninvasive, less expensive alternative to endomyocardial biopsy for monitoring allograft rejection in cardiac transplant patients.

Biopsy↗