Carcinogenesis bioassay data system.
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Biomedical subjects
Publications and source records attributed to R L Martin.
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Thirty patients with peripheral arterial disease were evaluated using an ultrasonic duplex scanner. A total of 338 arterial segments from the level of the iliac to the popliteal artery were studied and compared with the results of arteriography read independently by two radiologists who were unaware of the results with the scanner. The results demonstrate that this method is not only suitable for clinical use but is as good as arteriography in defining both the location and extent of the arterial involvement.
We describe the results of a follow-up study on patients with hysteria using the Minnesota Multiphasic Personality Inventory (MMPI) to evaluate the multiple complaints of these patients. MMPIs were obtained from 29 women with primary affective disorder and 37 women with Briquet's syndrome as part of a follow-up study of the St. Louis clinic 500. Patients with Briquet's syndrome were significantly less consistent and logical in answering MMPIs and were more likely to emphasize personal psychopathological conditions. They reported many more symptoms in many more problem areas than did women with primary affective disorder. Patients with Briquet's syndrome reported significantly more somatic symptoms and psychological/interpersonal problems than did the depressed group. It was suggested that such patients mimic multiple psychiatric and somatic disorders.
INTRODUCTION: Emergency medical vehicle collisions (EMVCs) occurring during initial response and with patient transport have been a long-standing problem for emergency medical services (EMS) systems. Experience suggests "wake-effect" collisions occur as a result of an EMS vehicle's transit, but do not involve the emergency medical vehicle (EMV). Substantiating the existence and magnitude of wake-effect collisions may have major implications regarding the manner of EMV response. HYPOTHESIS: Paramedics will report that wake-effect collisions do occur and that they occur more frequently than do EMVCs. METHODS DESIGN: Survey analysis. PARTICIPANTS: Thirty paramedics employed by the Salt Lake City (Utah) Fire Department and 45 paramedics employed by Salt Lake County Fire Department. Geographic Area: Service area has population of 650,000 and is urban, suburban, and rural. MEASUREMENTS: The survey consisted of three open-ended questions concerning years on the job, EMVCs, and wake-effect collisions. ANALYSIS: The mean value for the number of EMVCs and wake-effect EMVCs, along with the 0.95 confidence intervals (0.95 CI) were determined. RESULTS: Seventy-three surveys were analyzed. Sixty EMVCs and 255 wake-effect collisions were reported. Overall, the mean value for the number EMVCs per respondent was 0.82 (0.60-1.05) and for wake-effect collisions 3.49 (2.42-4.55). The mean values for EMVC's for each service were 0.86 (0.50-1.38); 0.80 (0.50-11.0). For wake-effect collisions the mean values were 4.59 (2.83-6.35); and 2.76 (1.46-4.06) respectively. CONCLUSIONS: This study suggests that the wake-effect collision is real and may occur with greater frequency than do EMVCs. Significant limitations of this study are recall bias and misclassification bias. Future studies are needed to define more precisely wake-effect collision prevalence and the resulting "cost" in regards to injury and vehicle/property damage.
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Delrin (DR) has been used in biomedical applications for more than 25 years. Because of durability concerns, it was replaced by the expensive Pyrolytic Carbon (PC) in numerous cardiac valves. However, the durability problem could be related to design rather than poor materials selection. Recent reports on brittle fracture of PC, leading to sudden deaths, have prompted a critical comparison between DR and PC in the St. Vincents Mechanical (SVM) heart valves. Three SVM-DR and SVM-PC valves were subjected to accelerated life cycle tests, and examined for wear at 400 million cycles. These results were compared to those of Björk-Shiley Delrin (BS-DR) valves. Wear in BS-DR valves in vivo for more than 17 years were also analyzed and compared. Using a linear (wear depth)-log (cycles) plot, wear rates in mm/log (million cycles) were obtained. The results showed that the wear rates for DR and PC in SVM valves are close. The double reduction in wear rate of the SVM-DR, compared to BS-DR, is probably due to the lower contact stresses of the SVM valves. SVM-DR in vivo should, therefore, have lower wear. The PC discs also showed edge chipping and hairline cracks. The authors conclude that the durability of DR can be improved by design and, since it is more impact resistant than PC, it is a safer, more inexpensive occluder material for cardiac valves.