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31.
A primary duodenal small-cell neuroendocrine carcinoma was found in an elderly man who presented with upper abdominal pain. Although metastatic small-cell carcinoma was documented by liver biopsy, the primary lesion was not identified until postmortem examination. The latter tumor, which ulcerated the duodenal mucosa, was composed of small ovoid cells with sparse cytoplasm and granular chromatin. Electron microscopy revealed cytoplasmic dense-core granules. Immunocytochemical study demonstrated the presence of neuron-specific enolase, Leu 7 antigen, chromogranin, epithelial membrane antigen, and vasoactive intestinal polypeptide within tumor cells. However, there was no evidence of a clinical endocrinopathy. This case emphasizes the need to include the duodenum as a possible primary site when metastatic small-cell neuroendocrine carcinoma is seen in the absence of apparent pulmonary disease.  相似文献   
32.
In the early 1970s, affirmative-action programs were introduced to accomplish a number of social goals, including increasing the supply of minority physicians and improving the health care of the poor. To assess the success of such programs, we analyzed data on people who graduated from U.S. medical schools in 1975 to determine how specialty choice, practice locations, patient populations served, and board-certification rates differ between minority and nonminority graduates. A larger proportion of minority graduates (55 per cent vs. 41 per cent, P less than 0.001) chose the primary-care specialties of family practice, general internal medicine, general pediatrics, and obstetrics-gynecology. Significantly more minority physicians (12 per cent vs. 6 per cent, P less than 0.01) practiced in locations designated as health-manpower shortage areas by the federal government and had more Medicaid recipients in their patient populations (31 per cent for blacks, 24 per cent for Hispanics, 14 per cent for whites; P less than 0.001). Physicians from each racial or ethnic group served disproportionately more patients of their own racial or ethnic group (P less than 0.001), but minority physicians did not serve significantly more persons from other racial or ethnic minority groups than did nonminority physicians. Many minority physicians served patient populations much like those of their nonminority colleagues, which indicates that substantial integration of the medical marketplace has taken place. Significantly fewer minority graduates had become board-certified by 1984 (48 per cent vs. 80 per cent, P less than 0.001), and most of this disparity was associated with differences in premedical-school characteristics and in the patient populations they served. Our analysis shows that minority graduates of the medical school class of 1975 are fulfilling many of the objectives of affirmative-action programs.  相似文献   
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The degree of muscular ischemia and its reversibility can be quantified in the early stages. This histochemical enzymatic study utilized Nitroblue tetrazolium (NBT) which when reduced by tissue dehydrogenase produces a blue pigment: "formazan." Seventy Wistar rats were subjected to transient hindlimb ischemia by means of a tourniquet for 3, 6, 9, 12, 15 and 18 hours, followed by reperfusion. Microsurgical muscle biopsies were obtained in each rat at 1 and 12 hours, and 3, 7, 14 days after reperfusion. Time increased in muscle staining demonstrated a succino-dehydrogenase deficit confirmed by clinical and histopathological follow-up. NBT staining time was 2 minutes (+/- 8 sec.) in the control group, between 2 and 6 minutes in the reversible ischemia group (rats with 3 and 6 hours of tourniquet), and more than 9 minutes (+/- 14 sec.) in the irreversible ischemia group (animals with more than 9 hours of tourniquet). In vascular surgery and in limb reimplantation this protocol is a practical method of evaluating cytoplasmic enzymatic activity and the status of myofibrillar oxidation in the early phases of ischemic injury, before histologic changes are clearly delineated.  相似文献   
35.
PURPOSE: Most medical schools test their students throughout the curriculum using in-house examinations written by the faculty who teach the courses. The authors assessed the quality of in-house examinations used in three U.S. medical schools. METHOD: In 1998, nine basic science examinations from the three schools were gathered and each question was subjected to quality assessment by three expert biomedical test developers, each of whom has had extensive experience in reviewing and evaluating questions for the United States Medical Licensing Examination (USMLE) Steps 1 and 2. Questions were rated on a five-point scale: 1 = tested recall only and was technically flawed to 5 = used a clinical or laboratory vignette, required reasoning to answer, and was free of technical flaws. Each rater made independent assessments, and the mean score for each question was calculated. Mean quality scores for National Board of Medical Examiners (NBME) who were trained question writers were compared with the mean scores for question writers without NBME training. The raters' quality assessments were made without knowledge of the test writers' training background or the study's hypothesis. RESULTS: A total of 555 questions were analyzed. The mean score for all questions was 2.39 +/- 1.21. The 92 questions written by NBME-trained question writers had a mean score of 4.24 +/- 0.85, and the 463 questions written by faculty without formal NBME training had a mean score of 2.03 +/- 0.90 (p <.01). CONCLUSIONS: The in-house examinations were of relatively low quality. The quality of examination questions can be significantly improved by providing question writers with formal training.  相似文献   
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37.
St. Paul-Ramsey Medical Center in St. Paul, MN became one of the first hospitals in the United States to initiate a "stockless" par level inventory system. Successes with stockless led the hospital to look at implementing it in the OR to achieve a reduction of expense to revenue. Materiel Management and Surgical Services discussed a number of issues relevant to implementing a stockless program, including product flow, accuracy and cost of case carts and preference cards, item pricing, committed usage of items brought into the system and establishment of a steering committee. Specific OR issues and practices required evaluation and adjustment, such as the routine use of emergency direct ordering. Information systems support was brought in and a products committee established to do education and oversee the program. Savings for 1993-94 were $185,146.  相似文献   
38.
The likely development of healthcare alliances and affiliations will create a logical role for multicentered DUEs that study treatment regimens or indications in a healthcare system made up of several institutions. Such a study is under way in New Jersey, involving 15 hospitals. The DUE is evaluating usage patterns of ticarcillin/clavulanate and two other broad-spectrum antibiotics. A multicenter DUE presents challenges, such as the need for additional resources and for consensus among disparate elements; but this methodology also opens up expanded roles for pharmacists, including participation in quality assurance activities.  相似文献   
39.
Purpose This study examined sperm motion parameters as measured by computerized automated semen analysis before and after a Percoll wash and determined if differences in any parameter were correlated with fertility subsequent to intrauterine insemination (IUI).Results Total motile sperm decreased following the washing procedure from 79.0 ± 9.0 to 37.2 ± 7.6 million sperm. Motility increased from a mean of 43.4% to 61.7% (P<0.001). Other motility parameters also changed significantly (P<0.001) as follows: curvilinear velocity (VCL), 43.4 to 61.7 m/s; straight-line velocity (VSL), 21.3 to 26.7 m/s; linearity 53.1 to 45.2%; lateral head displacement (ALH), 2.97 to 3.94 m. Similar changes occurred following a swim-up preparation, although changes in mean motility, VCL, and ALH were significantly greater when compared to Percoll. The postwash changes were not accounted for merely by time lapse in preparation since reanalyzed untreated controls did not show the same changes in motion parameters. Prewash linearity in those specimens which resulted in pregnancies was greater than in those which did not (P=0.28). No other significant differences in pre-or post-Percoll washed sperm motion parameters were found between pregnant vs nonfertile cycles.Conclusion Following Percoll wash all CASA-generated motility parameters were significantly altered, but there was little association between these parameters and pregnancy achieved in IUI cycles.Presented at the 50th Annual Meeting of the American Fertility Society, San Antonio, Texas, November 5–10, 1994.  相似文献   
40.
Non-synaptic release may be the major route of excitatory amino acid (EAA) efflux during cerebral ischemia. Possible routes of non-synaptic release include non-specific anion channels, reversal of Na+-, CI?-, or Ca2+-dependent uptake, and cell lysis. In the present study we employ a novel approach to show reversal of Na+-dependent uptake as a major route of EAA efflux from astrocyte cultures under conditions of energy failure. Primary rat astrocyte cultures were subjected to combined blockade of glycolytic and oxidative metabolism after incubation with [3H]-D-aspartate (D-ASP). Energy failure produced an efflux of D-ASP that was maximal by 90 minutes. The efflux over this period was reduced by more than 50% in cells that had been pre-loaded with PDC (L-transpyrrolidine-2,4-dicarboxylic acid) or TBHA (threo-β-hydroxyaspartic acid), compounds that are competitive inhibitors of Na+-dependent glutamate uptake. The effect of pre-loading with the inhibitors was concentration dependent. No effect was seen if the inhibitors were added after induction of energy failure, suggesting that the attenuation of D-ASP efflux resulted from binding of the inhibitors to an intracellular site. These results provide strong evidence that EAA efflux from astrocytes under conditions of energy failure occurs largely through reversal of Na+-dependent uptake. © 1995 Wiley-Liss, Inc.
  • 1 This article is a US Government work and, as such, is in the public domain in the United States of America.
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