Faculty Bibliography

We demonstrated the use of the World Wide Web for the presentation and explanation of a medical decision model. We put on the web a treatment model developed as part of the Cardiac Arrhythmia and Risk of Death Patient Outcomes Research Team (CARD PORT). To demonstrate the advantages of our web-based presentation, we critiqued both the conventional paper-based and the web-based formats of this decision-model presentation with reference to an accepted published guide to understanding clinical decision models. A web-based presentation provides a useful supplement to paper-based publications by allowing authors to present their model in greater detail, to link model inputs to the primary evidence, and to disseminate the model to peer investigators for critique and collaborative modeling

Molecular fingerprinting techniques are rapidly becoming indispensable tools for hospital epidemiology. On the other hand, the relative complexity and unfamiliarity of these techniques to most hospital diagnostic laboratories limit their usefulness. In an attempt to provide a solution for this dilemma, we tested the feasibility and efficacy of a cooperative venture in which molecular typing of isolates recovered from patients in six hospitals was performed at two microbiology research laboratories with expertise in these techniques. In a small preliminary study, 30 methicillin-resistant Staphylococcus aureus (MRSA) and 30 vancomycin-resistant Enterococcus faecium (VREF) isolates were collected over a 3-week period from six hospitals in the metropolitan New York area and transported to the Laboratory of Microbiology at The Rockefeller University during the summer months of 1994. Nineteen of the 27 confirmed MRSA isolates were closely related strains carrying the same mecA and the same Tn554 polymorphs in a pulsed-field gel electrophoresis (PFGE) background represented by closely related subtypes of a single pattern, indicating the wide distribution of this MRSA clone among the participating hospitals. Typing of the same 27 MRSA isolates was also performed at the Tuberculosis Center of the Public Health Research Institute and identical results were obtained. The 29 confirmed VREF isolates were highly heterogeneous and belonged to as many as 23 distinct clonal types as defined by PFGE patterns and probing with vanA. Characterization of the 60 isolates by these methods was completed in one month of full-time effort by a single experienced laboratory assistant guided by a doctoral-level expert in molecular fingerprinting techniques. The collection of samples for both MRSA and VREF was not intended to address epidemiological questions but to determine the feasibility of a multicenter study. On the basis of our preliminary findings we are encouraged that a larger cooperative effort is possible and with the correct sampling method we believe that epidemiological and surveillance studies could be accomplished that would provide a tracking system to assist hospitals, clinics, and chronic care facilities in controlling the spread of multidrug-resistant pathogens

We have detected new clues to the composition and function of 'Transfer Factor' using the direct Leucocyte Migration Inhibition (LMI) test as an in vitro assay of Dialysates of Leucocyte Extracts (DLE). This approach has revealed two opposing antigen-specific activities to be present in the same > 3500 < 12,000 DA dialysis fraction - one activity is possessed of Inducer/Helper function (Inducer Factor). The opposing activity is possessed of Suppressor function (Suppressor Factor). When non-immune leucocyte populations are cultured with Inducer Factor they acquire the capacity to respond to specific antigen and inhibition of migration occurs. This conversion to reactivity is antigen-specific and dose-dependent. When immune leucocyte populations are cultured with Suppressor Factor their response to specific antigen is blocked and Inhibition of Migration is prevented

DLE was prepared from the minority of euglycemic CD-1 mice, previously injected with STZ, and was administered to hyperglycemic CD-1 male mice 1, 2 and 3 weeks after completion of multidose STZ. Mice treated with DLE derived from 2 x 10(7) (IX) or 10(8) lymphocyte equivalents (lymph.equ) were significantly less hyperglycemic than the saline treated controls (P < 0.001). The effects of DLE remained evident for more than 10 weeks after the final DLE treatment. Mice treated with DLE prepared from diabetic mice (hg DLE) developed a somewhat more rapid onset of hyperglycemia than the STZ treated control animals, although this effect did not achieve statistical significance (P = 0.1). This DLE was absorbed on a rat insulinoma cell line (RIN), which contains interspecies cross-reacting islet antigens, and compared to the unabsorbed DLE. Mice treated with hg DLE preabsorbed on RIN cells, showed a slower onset of hyperglycemia. DLE prepared from euglycemia mice and the RIN-absorbed fraction were equally capable of preventing hyperglycemia (P < 0.05). In order to determine whether the DLE effects were genetically restricted, DLE was prepared from BALB/c mice, normally resistant to the diabetogenic effects of multidose STZ, both before and after STZ treatment. STZ primed CD-1 mice treated with 3 weekly doses of 2 x 10(7) lymph. equ. of untreated BALB/c derived DLE, STZ treated BALB/c derived DLE, and STZ treated CD-1 DLE were all less hyperglycemic than the control mice, who received saline (P < 0.001). However, mice treated with CD-1 DLE were less hyperglycemic than the mice given BALB/c derived DLE (P < 0.05). These effects were relatively long-lived. Mice that were given the > 3,500 Dalton fraction of CD-1 DLE were significantly less hyperglycemic than either the control mice or those treated with the < 3,500 Dalton fraction of CD-1 DLE (P < 0.05). Effects remained evident for more than 3 months after the last dose of DLE. Pancreatic tissue from the mice treated with the > 3,500 Dalton fraction of CD-1 derived DLE revealed slightly more islets of a slightly greater size with less surrounding inflammation than either control mice or mice treated with the < 3,500 Dalton fraction of DLE