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Biomedical subjects

David Shalowitz

Publications and source records attributed to David Shalowitz.

3 recordsLinked to original sources

Informed consent for research and authorization under the Health Insurance Portability and Accountability Act Privacy Rule: an integrated approach.

Researchers have found that implementation of the Health Insurance Portability and Accountability Act (HIPAA) Privacy Rule is having a negative impact on clinical research. This impact traces, in part, to many research institutions complying with HIPAA by adding lengthy, complex language to their research consent documents. The addition of extensive language burdens institutional review boards and may undermine participants' understanding of the research in which they take part. Comparative analysis reveals, however, that the addition of lengthy text often is unnecessary. The U.S. federal requirements for informed consent for human subjects research and the HIPAA Privacy Rule's requirements for individual authorization overlap substantially. Hence, consent forms that satisfy the U.S. federal regulations for human subjects research need only minimal additional text to also satisfy the authorization requirements under the HIPAA Privacy Rule.

Biomedical Research↗

T cell activation causes diarrhea by increasing intestinal permeability and inhibiting epithelial Na+/K+-ATPase.

Inflammatory bowel disease (IBD) is associated with mucosal T cell activation and diarrhea. We found that T cell activation with anti-CD3 mAb induces profound diarrhea in mice. Diarrhea was quantified by intestinal weight-to-length (wt/l) ratios, mucosal Na(+)/K(+)-ATPase activity was determined and ion transport changes were measured in Ussing chambers. Anti-CD3 mAb increased jejunal wt/l ratios by more than 50% at 3 hours, returning to base line after 6 hours. Fluid accumulation was significantly reduced in TNF receptor-1 (TNFR-1(-/-)), but not IFN-gamma knockout mice. Anti-CD3 mAb decreased mucosal Na(+)/K(+)-ATPase activity, which was blocked by anti-TNF mAb and occurred to a lesser degree in TNFR-1(-/-) mice. Neither alpha nor beta subunits of Na(+)/K(+)-ATPase decreased in abundance at 3 hours. Intestinal tissue from anti-CD3-treated mice exhibited increased permeability to mannitol at 1 hour and decreases in electroneutral Na(+) absorption, Na(+)-dependent glucose absorption, and cAMP-stimulated anion secretion at 3 hours. Furthermore, enteral fluid accumulation was observed in CFTR(-/-) mice, indicating a minor role of active anion secretion. These data suggest that diarrhea in IBD is due to TNF-mediated malabsorption rather than to secretory processes. T cell activation induces luminal fluid accumulation by increasing mucosal permeability and reducing epithelial Na(+)/K(+)-ATPase activity leading to decreased intestinal Na(+) and water absorption.

Animals↗