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Biomedical subjects

B Kaplan

Publications and source records attributed to B Kaplan.

At least 451 records · Page 25Linked to original sources
PubMedDate not supplied

The effects of renal transplantation on circulating precursor dendritic cells.

BACKGROUND: Dendritic cells (DCs) are potent antigen-presenting cells that induce and regulate immune responses. Recent advances allow accurate quantification of peripheral blood (PB) myeloid and plasmacytoid DC populations (mDC and pDC, respectively), although the response to renal transplantation (RT) remains unknown. METHODS: Using flow cytometry, PBDC levels were quantified in patients with end-stage renal disease (ESRD) undergoing renal transplantation. RESULTS: PBDC levels were significantly reduced in ESRD patients pretransplantation compared to healthy controls, with further reduction noted immediately following a hemodialysis session. RT resulted in a dramatic decrease in both subsets, with a greater reduction of pDC levels. Both subset levels were significantly lower than in control patients undergoing abdominal surgery without RT. Subgroup analysis revealed significantly greater mDC reduction in RT recipients receiving antilymphocyte therapy, with preferential binding of antibody preparation to this subset. Samples from later time points revealed a gradual return of PBDC levels back to pretransplant values concurrent with overall reduction of immunosuppression. Finally, PBDC levels were significantly reduced in patients with BK virus nephropathy compared to recipients with stable graft function, despite lower overall immunosuppression. CONCLUSIONS: Our findings suggest that PBDC levels may reflect the degree of immunosuppression in renal allograft recipients. Furthermore, PBDC monitoring may represent a novel strategy to predict important outcomes such as acute rejection, long-term graft loss, and infectious complications.

Adult↗
PubMedDate not supplied

Prepregnancy genetic testing for age-related aneuploidies by polar body analysis.

Current practice for prevention of chromosomal aneuploidies involves prenatal screening and termination of pregnancy, a procedure that is not universally acceptable. We introduced prepregnancy genetic testing by sampling and fluorescence in situ hybridization (FISH) analysis of the first and second polar body (PB), to avoid fertilization and transfer of embryos resulting from aneuploid oocytes. In 395 in vitro fertilization (IVF) patients of advanced maternal age, the first and second PBs were removed following their extrusion from oocytes and studied by FISH, using probes specific for chromosomes 13, 18, and 21, to detect and avoid the transfer of oocytes with common aneuploidies. Overall, 3,651 oocytes obtained from 598 IVF cycles were available for FISH analysis, with 2,952 showing interpretable FISH results (80.9%). The analysis revealed 1,271 (43.1%) oocytes with aneuploidy, which were excluded from transfer and subjected to follow-up FISH analysis to confirm PB diagnosis in the cleavage or blastocyst stage embryos. Only embryos originating from 1,681 aneuploidy-free oocytes were transferred back to patients, resulting in 119 pregnancies overall, from which 78 healthy children have already been born, 35 were spontaneously aborted, and 16 are ongoing, after confirming PB diagnosis by prenatal diagnosis. The results demonstrate that PB-based preimplantation diagnosis may be used for prepregnancy screening in women with age-related risk for common aneuploidies.

Aneuploidy↗
PubMedDate not supplied

Management issues in automating medical systems.

The nontechnical aspects of medical computing systems are as important as the technical. In order to understand why, it is important to consider the social context of systems, the human engineering necessary for medical systems to work, and the specifics of the man-machine interface. It is also necessary to plan for the change which comes with any new method. This paper contains a discussion of these topics, concluding with a set of guidelines for change-management which we feel organizes the data of years of experience into a systematic approach.

Computers↗
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Addressing organizational issues into the evaluation of medical systems.

New system design and evaluation methodologies are being developed to address social, organizational, political, and other non-technological issues in medical informatics. This paper describes a social interactionist framework for researching these kinds of organizational issues, based on research within medical informatics and other disciplines over the past 20 years. It discusses how effective evaluation strategies may be undertaken to address organizational issues concerning computer information systems in medicine and health care. The paper begins with a theoretical framework for evaluation. It then describes the 4Cs of evaluation: communication, care, control, and context. Five methodological guidelines are given for conducting comprehensive evaluations that address these 4Cs. An example of an evaluation research design that fits the guidelines and was used in an evaluation of an on-line clinical imaging system is discussed. Results of the evaluation study illustrate how this approach addresses organizational concerns and the 4Cs.

Communication↗
PubMedDate not supplied

Toward an informatics research agenda: key people and organizational issues.

As we have advanced in medical informatics and created many impressive innovations, we also have learned that technologic developments are not sufficient to bring the value of computer and information technologies to health care systems. This paper proposes a model for improving how we develop and deploy information technology. The authors focus on trends in people, organizational, and social issues (POI/OSI), which are becoming more complex as both health care institutions and information technologies are changing rapidly. They outline key issues and suggest high-priority research areas. One dimension of the model concerns different organizational levels at which informatics applications are used. The other dimension draws on social science disciplines for their approaches to studying implications of POI/OSI in informatics. By drawing on a wide variety of research approaches and asking questions based in social science disciplines, the authors propose a research agenda for high-priority issues, so that the challenges they see ahead for informatics may be met better.

Delivery of Health Care↗