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Biomedical subjects

M A Simpson

Publications and source records attributed to M A Simpson.

At least 37 records · Page 2Linked to original sources
PubMed1996

Studying the impact of women on osteopathic physician workforce predictions.

Women have been entering the physician workforce in ever-increasing numbers since the 1970s, and women are expected to reach numeric parity with men early in the next century. In an effort to predict changes in the physician workforce, analysts have relied primarily on data collected in the allopathic medical profession. Documented differences in practice characteristics between osteopathic and allopathic physicians make current workforce projections--based heavily on assumptions rooted in the allopathic medical profession--nonrepresentative of the osteopathic medical profession. The authors attempt to identify the impact of increasing numbers of women physicians on the osteopathic medical profession. They trace the historical presence of women in medicine and explore speculations concerning the continued growth in the numbers and percentage of women in medicine. The authors analyze data from the 1992 AOA census in search of identifiable trends in practice location and specialty choice based on gender, marital status, and dual-osteopathic physician couples. Finally, they discuss the need for complete and accurate data collection for the profession as data-driven workforce policy decisions ultimately affect the entire profession.

Female↗
PubMed1996

Cyclosporine bioavailability: dosing implications and impact on clinical outcomes in select transplantation subpopulations.

Reports in the literature indicate that clinical outcomes in select patient subpopulations have been inferior to those in the general transplantation population. Of potential interest in this regard is the finding that lower cyclosporine bioavailability correlates with a higher incidence of acute rejection and graft loss. To gain insights into these issues, we examined data from renal transplant recipients at our own centers and in one large data base. Our experience revealed that cyclosporine bioavailability was markedly lower in patients who developed acute or chronic rejection than in those with stable graft function. An analysis by demographic or clinical factors showed that cyclosporine bioavailability was lower in diabetics and black patients. In one study, diabetics required much higher daily doses of cyclosporine to achieve outcomes comparable to those in non-diabetics; even then, diabetics attained lower cyclosporine blood levels. Other work found that long-term graft survival rates were poorer in blacks, even though cyclosporine dosages and blood levels were comparable to those in whites. A case-controlled study from the pregnancy registry found that cyclosporine dosages were consistently higher in pregnant patients who maintained good graft function than in those who experienced graft dysfunction. These results suggest that the subpopulations examined should receive immunosuppression with higher cyclosporine dosages than those used in the general transplantation population. These subpopulations may also benefit from a cyclosporine formulation that provides better absorption, resulting in more consistent and predictable cyclosporine bioavailability.

Biological Availability↗
PubMed1995

Kidney transplantation in diabetic patients using cyclosporine. Five-year follow-up.

OBJECTIVE: To review our center's experience with kidney transplantation in diabetic recipients; specifically, to compare long-term (5-year) patient and graft survival rates between diabetic and nondiabetic recipients overall and according to donor source using cyclosporine-based immunosuppression. DESIGN: A retrospective review of all kidney transplants performed over the 7-year period from 1987 to 1993. SETTING: A large urban tertiary care referral center with a long history of kidney transplantation and care of the diabetic patient. PATIENTS: All patients receiving a kidney transplant, either alone or simultaneously with a pancreas transplant, were reviewed. MAIN OUTCOME MEASURES: Actuarial patient and graft survival, serum creatinine levels, and causes of late graft loss. RESULTS: There was no significant difference in actuarial 5-year patient or kidney graft survival between diabetic and nondiabetic recipients overall or when analyzed by donor source. There was no significant difference in mean serum creatinine levels at 5 years between diabetic and nondiabetic recipients overall or between diabetic and nondiabetic cadaveric recipients. While chronic rejection was the major cause of late graft loss in nondiabetic recipients, death with a functioning graft, principally due to cardiovascular disease, was the major cause of graft loss in diabetic recipients. CONCLUSIONS: With cyclosporine-based immunosuppression, diabetic kidney transplant recipients have 5-year patient and graft survival rates and allograft function comparable to nondiabetic recipients. Given the high mortality of diabetic patients receiving dialysis, kidney transplantation is the treatment of choice for end-stage diabetic renal disease.

Actuarial Analysis↗
PubMed1994

Complexity of the healthcare crisis in rural America.

Because osteopathic physicians comprise 15.3% of all physicians in small rural counties, while making up only 5.1% of the nation's physicians, the solutions to the healthcare crisis for rural America are of special interest to them. The authors explore the incredible diversity of rural communities and the difficulty with defining the term "rural." They give the background of efforts to address rural health problems and the reasons accessible healthcare--available, acceptable and affordable--has been so elusive in rural settings. The authors also explain the relative success of the osteopathic medical profession and address the role osteopathic physicians can play in the future. Finally, they explore the exciting new possibilities that telemedicine offers.

Health Care Reform↗
PubMed1994

A comparison of operation, endoscopic retrograde cholangiopancreatography, and percutaneous transhepatic cholangiography in biliary complications after hepatic transplantation.

BACKGROUND: Biliary complications (BC) remain a significant cause of morbidity and mortality after orthotopic liver transplantation (OLT). STUDY DESIGN: In an effort to determine the incidence of BC after OLT and the success of management options, 157 hepatic transplants performed from January 1987 to July 1991 were reviewed. RESULTS: The incidence of BC was 25 percent, with a one year mortality rate of 43.5 percent compared with 23.4 percent for patients in a control group (p < 0.05). Most BC occurring before postoperative day 30 presented as leaks, with a one year mortality rate of 50 percent (p < 0.03 versus control group). Biliary complications presenting after postoperative day 30 presented as strictures, with a one year mortality rate of 36.8 percent (p = NS versus control group). Endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTHC), and operative treatment were analyzed to determine relative patency rates after intervention for BC. The analysis showed that ERCP and PTHC were equivalent, with a one year patency rate of 45 percent. Operative treatment had a patency rate of 89 percent (p < 0.05 compared to ERCP and PTHC). CONCLUSIONS: The results from ERCP and PTHC may be useful for delineation of rejection versus BC after OLT. However, operative treatment is significantly more effective for definitive treatment of BC after OLT.

Adult↗
PubMed1991

Sequential interleukin 2 and interleukin 2 receptor levels distinguish rejection from cyclosporine toxicity in liver allograft recipients.

Previous studies of renal transplant recipients have demonstrated that allograft rejection is accompanied by an increase in plasma and urinary levels of interleukin 2 and its soluble receptor before the development of clinical symptoms. After measuring interleukin 2 and interleukin 2 receptor levels in the plasma, bile, and urine of liver transplant recipients, we found that rejection is preceded by elevation of plasma and biliary levels of both substances, that cyclosporine toxicity did not affect either of these levels, and that urinary levels of the substances are unaffected in either condition. Levels of interleukin 2 and interleukin 2 receptors increased in bile earlier than in plasma, and interleukin 2 levels did not overlap among stable patients and those experiencing rejection, whereas levels of interleukin 2 receptors did. Serial measurements of interleukin 2 levels, particularly in the product of the transplanted organ, provide a reliable assessment of the immunologic status of the allograft.

Bile↗
PubMed1991

Prevention of graft-versus-host disease following small bowel transplantation with polyclonal and monoclonal antilymphocyte serum. The effect of timing and route of administration.

Graft-versus-host disease is a potential problem following small bowel transplantation. We have previously shown that a two-day intraperitoneal course of polyclonal antilymphocyte serum completely prevents GVHD without impairing allograft function in a unidirectional rat small bowel transplant model. In the present study we sought to determine the optimum route and timing of ALS administration and whether donor pretreatment with the anti-T cell receptor monoclonal antibody R73 would be similarly effective in preventing GVHD. Both intravenous and intraperitoneal injection of ALS effectively prevent GVHD in this model. ALS must be given to donors at least 48 hr prior to graft procurement for maximum effectiveness. Prevention of GVHD correlates with lymphocyte depletion in mesenteric lymph nodes, as opposed to peripheral blood or small bowel lamina propria. Donor pretreatment with the monoclonal antibody R73 significantly delays the onset of GVHD in this small bowel transplant model but appears less effective than polyclonal ALS.

Animals↗
PubMed1991

Immunologic heterogeneity among potential transplant recipients. Prospects for predicting immune responses to allografts with in vitro tests.

The ability to accurately predict the response of a specific patient to a specific organ allograft has long been a goal of organ transplantation. The role of histocompatibility antigens in determining the acceptance or rejection of an allograft-recipient combination has been thoroughly investigated, but is being reevaluated as improved immunosuppressive agents become available. Early efforts at immunologic monitoring are reviewed in addition to more recent efforts that focus on the cellular and molecular mediators of immunity. The authors' own experience with lymphokine measurements in clinical transplantation is also reviewed, with emphasis on the role of interleukin-2 (IL-2) and its soluble receptor (IL-2R) in various transplant-associated conditions. The authors conclude that information useful in the management of transplant patients may be derived from serial measurements of IL-2 and IL-2R, but that infections, especially CMV, may not be ruled out with certainty by these measurements alone. The available data suggest that study of additional lymphokines such as interferon-gamma (IFN-gamma) and tumor necrosis factor (TNF) may be useful in discriminating rejection from infections in transplant patients.

Antigens, Surface↗