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151.
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With the longer life expectancy of the population, calcific aortic stenosis has become a common cardiac problem in the elderly. When patients with moderate to severe aortic stenosis become symptomatic, the prognosis is usually poor in absence of valve replacement and sudden death is a feared complication. It has been hypothesized that malignant ventricular arrhythmias could be responsible for the high incidence of sudden death in symptomatic patients with aortic stenosis. The purpose of this review is to analyze the prevalence, the electrophysiologic mechanisms, and the possible role of ventricular arrhythmias in the development of symptoms and in the outcome of adult subjects with aortic stenosis.  相似文献   
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Congestion in a store-and-forward data communications network manifests itself by a rapid degradation of network throughput and a fast increase in the average transit delay. A study of a congestion control mechanism in a packet-switched data network is presented. Buffer limits are placed on the input, transit and exit packets in each switching node. By a judicious choice of the buffer limits, it is shown that the network throughput can be maintained at a constant level, while the average transit delay remains within acceptable bounds for offered loads beyond the congestion point.  相似文献   
155.
Small fibrin-platelet emboli caused by prolapsed mitral valves may cause retinal occlusive disease with a wide range of ophthalmic manifestations, including amaurosis fugax in young people, retinal or choroidal arteriolar occlusion, and retinal neovascularization (atypical Eales' disease). Six patients with retinal occusive disease underwent extensive noninvasive cardiac and systemic tests and were found to have prolapsed mitral valves. Patients with unexplained ocular emboli should be examined by a cardiologist for possible mitral valve prolapse.  相似文献   
156.
Although allergic persons can react to foods containing trace quantities of unlabeled or unintended food allergens, there are few data available on the quantities of these allergens required to evoke allergic symptoms. We report a milk-allergic 3-year-old boy who experienced throat itching, facial angioedema, and vomiting within 20 min of ingesting 4 to 6 oz (ca. 113.4 to 170.1 g) of lemon sorbet. Subsequent analysis of two sorbet samples provided by the parents and a third sample purchased locally by the investigators revealed trace quantities of milk allergens, whey protein (8.8 micrograms/ml), or lactose (200 ppm). The quantity of whey protein ingested was estimated to be 120 to 180 micrograms (equivalent to 23 to 24 microliters of milk). All three sorbet samples had been manufactured in the same plant within a 4-month period; the equipment used to produce and package the sorbet was also used to produce and package ice cream. No milk allergen or whey protein was detected in 38 other marketplace sorbet samples submitted by the manufacturer for testing. We concluded that trace quantities of whey proteins (< 200 micrograms) can elicit systemic reactions in exquisitely milk-allergic individuals. Such individuals should avoid eating frozen desserts prepared using equipment also used for producing or packaging ice cream, unless manufacturers can demonstrate unequivocally that their cleaning practices are sufficient to prevent milk contamination. Adequate tests are not currently available to food manufacturers but are under development.  相似文献   
157.
We investigated the number and seriousness of moon-car accidents in our region (a moon-car is a toy-vehicle, see Fig. 1). The study was retrospective combined with a telephone-interview. Forty-seven patients were seen in the emergency room after a moon-car accident in the period 1/1 1990-31/12 95. There were 12 fractures, including five fractures of the tibial shaft and one supracondylar humeral fracture which was operated. There were 17 wounds, 14 of which were sutured. Seventeen patients had distorsions/contusions, three cases of head contusions (observed for concussion) and two with teeth damages. We found that the number of moon-car accidents is increasing (13 patients the last year), and that the accidents are not only minor. New rules in day care centres should be able to especially limit the number of more serious accidents.  相似文献   
158.
Prompted by evidence suggesting preserved red cell deformability in cardiac surgical patients pretreated with pharmacologic dosages of methylprednisolone, we performed in vitro experiments to examine the ability of similar levels of methylprednisolone and hydrocortisone to modify erythrocyte membrane changes produced by metabolic depletion or membrane-active compounds. Variables measured included cell morphology, blood biscosity, membrane deformability, osmotic fragility, red cell cholesterol, and glycolytic intermediates. In incubated samples, methylprednisolone partially prevented the transition of discs to echinocytes, the rise in whole blood viscosity, the decrease in membrane deformability, and the loss of red cell cholesterol which accompany ATP depletion, but it had no apparent effect on red cell glycolysis. The drug also inhibited esterification of cholesterol in cell-free serum. In unimcubated samples to which lysolecithin was added, methylprednisolone partially prevented and reversed morphologic and rheologic responses without affecting membrane cholesterol. Hydrocortisone demonstrated similar properties. Possible mechanisms for these actions are discussed. The concept is advanced that preserved blood fluidity may contribute to the beneficial responses to these drugs in certain clinical conditions.  相似文献   
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Reviews the psychological factors of diabetes with respect to etiology, psychological impact and adjustment to the disease, family dynamics, and psychological programs to aid diabetes management. Stress appears to influence metabolism both directly and indirectly. Little evidence exists for a consistent pattern of traits that typifies diabetes or poor management of the disease. Several studies have shown diverse psychological problems related to diabetes, especially in the area of social problems and peer relationships among juveniles. A variety of psychological interventions may be helpful in the care of diabetes; however, none of these are conclusively useful. Research should clarify the role of stress and stress management and focus on psychological factors related to metabolic control. Treatment research needs careful specification of interventions and measurement of both behavioral and metabolic outcomes so that connections among them may be assessed. (97 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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