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61.
Elizabeth A. Gilpin James A. Koziol Erling B. Madsen Hartmut Henning John Ross 《The American journal of cardiology》1983,52(3):240-244
The mortality rate after acute myocardial infarction (AMI) has generally been modeled by a single exponential function. The present study was undertaken to determine, in 3 different populations, whether or not periods exist during the first year after AMI which have mortality distributions that differ from this pattern. The 3 patient populations included San Diego (346 patients, 71 deaths), Vancouver (704 patients, 146 deaths), and Copenhagen (1,140 patients, 262 deaths). Hospital admission was within 24 hours of the onset of symptoms, and patients dying within the first 24 hours after hospital admission or of noncardiac or unknown causes were not analyzed. The mortality between 2 and 21 days in the combined data base was 11.4% (range 10.9 to 11.7) and from 3 weeks to 1 year 10.5% (range 9.0 to 11.3). A high degree of similarity was noted among the shapes of the 3 survival curves. The hypothesis of an exponential mortality rate during the entire first year was rejected. Using a special statistic, changepoints at days 17,23, and 24 in the 3 populations (21 days for the combined data base) were identified and used thereafter to divide the year into 2 separate periods of mortality within which exponentiality for the mortality rate was not rejected. The point by which exactly 50% of deaths had occurred was day 19, with 75% of deaths occurring by day 100. These data further define the natural history after AMI and indicate optimal follow-up periods for short- and longer-term management strategies based on risk assessment or trials of risk reduction after AMI. 相似文献
62.
B Ettinger E B Goldfield K C Burrill K Von Werder P H Forsham 《The American journal of medicine》1973,54(2):195-200
Clinical response and changes in plasma testosterone were measured in 22 hirsute women during the administration of dexamethasone, ethinyl estradiol-medroxyprogesterone, or both. The response of plasma testosterone to the administration of adrenocorticotropic hormone (ACTH), human chorionic gonadotropin (HCG) and dexamethasone was measured before treatment in 16 patients, and six additional patients were treated without initial testing. Patients were treated with three month courses of each therapy, regardless of their test results. Results of short-term testing did not correlate with those of long-term treatment. Previously elevated testosterone levels were suppressed in 80 per cent of the patients treated with dexamethasone and in all the patients treated with ethinyl estradiol-medroxyprogesterone (EE-MP).Hirsutism diminished in a third of the patients treated with dexamethasone and in half of the patients treated with EE-MP. Acne diminished in half of the patients with either therapy. There was good correlation between normalization of plasma testosterone levels and clinical improvement.Normal plasma testosterone levels were maintained for several months after dexamethasone treatment was discontinued.Recommendations are given for the approach to diagnosis and treatment of the female patient with hirsutism. 相似文献
63.
Atrial reentrance as a mechanism of the tachycardia was demonstrated in a 28-year-old patient suffering from chronic repetitive supraventricular tachycardia. Criteria for diagnosis included the following: (1) Repetitive supraventricular tachycardia was induced and terminated by properly timed atrial extrastimuli. (2) Return cycles of all atrial extrastimuli not abolishing the tachycardia were fully compensatory. (3) A-H prolongation was not a prerequisite to induce the tachycardia. (4) The contours of P and A waves during tachycardia differed from those in sinus rhythm, but atrial activation remained antegrade. (5) A concealed anomalous pathway could not be proved. 相似文献
64.
Mario R. Garcia-Palmieri Raul Costas Mercedes Cruz-Vidal Paul D. Sorlie Richard J. Havlik 《The American journal of cardiology》1982,50(4):749-755
The incidence and potential risk factors of coronary heart disease were assessed in 2,585 rural and 6,208 urban men, aged 45 to 64 years, participating in the Puerto Rico Heart Health Program, a prospective epidemiologic study of coronary heart disease initiated in 1965. An index of daily physical activity and a metabolic equivalent of heaviest activity were estimated from each individual history. Rural men had higher mean levels of overall activity as well as higher levels of heavy activity than urban men. An year follow-up study for coronary heart disease other than angina pectoris was analyzed for relationships with physical activity. Significant inverse associations were found for both urban and rural men. Metabolic equivalent of heaviest activity showed similar results. Although the physical activity index was inversely associated with most known coronary risk factors, multivariate analyses indicated that a significant independent inverse relationship existed with the incidence of coronary heart disease. In Puerto Rico, increased physical activity appears to be a separate protective factor against heart attacks. 相似文献
65.
Arthur R. Olshan Daniel T. Oconnor Irving M. Cohen John A. Mitas Richard A. Stone 《The American journal of medicine》1983,74(2):233-242
Ten patients with adult-onset diabetes in whom diabetes antedated the appearance of hypertension were evaluated. These patients had evidence of diabetic autonomic neuropathy, including significant orthostatic hypotension (four patients), impotence (three patients), and evidence of diabetic peripheral sensorimotor neuropathy (nine patients) in clinical testing and nerve conduction study results. Baroreflex function was evaluated by multiple hemodynamic tests, including inhalation of amyl nitrite and intravenous administration of phenylephrine, before and after parasympathetic blockade with atropine, and the cold presser test; results were compared with results in normal control subjects, patients with essential hypertension, and two subgroups of uremie patients undergoing maintenance hemodialysis. Baroreflex function was significantly abnormal in the diabetic patients and was consistent with combined parasympathetic and sympathetic motor nerve (efferent) dysfunction in the baroreflex arc. There was a significant inverse correlation between the degree of orthostatic hypotension in the diabetic patients and their baroreflex responsc to phenylephrine (r = ?0.680, p < 0.05). There was no significant correlation between supine hypertension in the patients with diabetes and any of the hemodynamic or biochemical parameters examined. The results suggest that orthostatic hypotension in these patients is related to baroreflex dysfunction. However, baroreflex dysfunction does not appear to be a factor in the development of hypertension in these patients, although more studies with normotensive diabetic patients are needed to confirm this point. 相似文献
66.
M J Cooper D Bernstein N H Silverman 《Journal of the American College of Cardiology》1985,6(4):923-926
A coronary-cameral fistula was inspected clinically by two-dimensional and pulsed Doppler ultrasound. At cardiac catheterization a fistulous connection between the left coronary artery and the right ventricle was observed. Contrast echocardiography using agitated saline solution injected into the aortic catheter clearly showed the passage of microcavitations into the left and the right ventricles confirming the connection of the fistula to both chambers. Contrast echocardiography is a valuable technique that can help define the site of drainage of coronary artery fistulas. 相似文献
67.
The mechanism of recovery of hepatic T4-5'-deiodinase during glucose-refeeding: role of glucagon and insulin 总被引:2,自引:0,他引:2
Refeeding studies were performed on male Sprague-Dawley rats that had been fasted for 72 hours to characterize the specific effect of carbohydrates on T3 metabolism. Fasting is associated with low serum T3 levels and reduced hepatic T4-5′-deiodinase activity (T4 → T3). Carbohydrate refeeding (20% glucose in H2O) normalized both the serum T3 and hepatic T4-5′-deiodinase activity within 72 hours, whereas fat (10% Intralipid) and amino acids (5.5% Travasol) had no effect after 72 hours of refeeding. Refeeding with a mixed diet (Purina Rodent Chow) occasionally reactivated hepatic T4-5′-deiodinase activity, however, normalization of enzyme activity did not occur within 72 hours. Time-course studies demonstrated that hepatic T4-5′-deiodinase activity was not stimulated until 24 hours of carbohydrate refeeding had elapsed and that 48 to 72 hours were required for normalization. The mechanism of the carbohydrate-refeeding effect was characterized by analyzing the alterations in the kinetics Michaelis constant (Km) and maximal velocity (Vmax) of hepatic T4-5′-deiodinase and the changes in the hepatic content of nonprotein sulfhydryl groups (NP-SH), which are possible enzyme cofactors. There was no relationship between the hepatic enzyme activity and the NP-SH response during the refeeding period. Moreover, homogenate enrichment with the sulfhydryl compound, dithiothreitol (DTT), did not alter the temporal profile of the enzyme recovery consequent to refeeding. Refeeding with carbohydrate had no effect on the Km of hepatic T4-5′-deiodinase but had a significant effect on the Vmax. Refeeding with glucose induced an increase in enzyme Vmax over the time-course, which became significant (P < 0.005) compared with the enzyme Vmax of the fasted group by 72 hours. During carbohydrate refeeding, a positive correlation was noted between the ratio of serum insulin to glucagon and hepatic-T4-5′-deiodinase activity (r = 0.82, P < 0.001), whereas a negative correlation was found between enzyme activity and the ratio of serum glucose to insulin (r = ?0.9, P < 0.001). Furthermore these correlations also applied during refeeding with fat and amino acids. Thus, the carbohydrate-refeeding reactivation of hepatic T4-5′-deiodinase in fasted rats is a delayed process that requires a refeeding period equivalent to the duration of fasting for enzyme normalization to occur. Recovery was due to an increase in the hepatic content of active enzyme rather than an enhancement of cofactor supply. The glucoregulatory hormones, glucagon and insulin, may modulate these carbohydrate induced changes on hepatic T4-5′-deiodinase. Moreover, the differential reaction of hepatic T4-5′-deiodinase to specific nutriments may be mediated by these glucoregulatory hormones. 相似文献
68.
David C. Aron James W. Findling Paul A. Fitzgerald Robert M. Brooks Frank E. Fisher Peter H. Forsham J.Blake Tyrrell 《The American journal of medicine》1981,71(2):302-306
Cushing's syndrome due to nodular adrenal hyperplasia comprises a clinically and biochemically heterogeneous group of disorders whose pathogenesis is unclear. We describe two patients with atypical steroid dynamics and large unilateral adrenal nodules who had pituitary ACTH-dependent disease. In the differential diagnosis of Cushing's syndrome, we recommend repeated ACTH measurement and selective venous sampling—particularly in those patients with impaired dexamethasone suppressibility and abnormal findings on computerized tomography. 相似文献
69.
目的 建立泻白散和方中3味主药甘草、地骨皮、桑白皮的体外抗氧化活性测定方法,并对31批药材和10批泻白散煎液的抗氧化活性进行测定。方法 采用紫外可见分光光度法检测一定浓度的药材提取液引起DPPH溶液吸光度(A)值降低,考察波长为517 nm,分别探索3味药材抗氧化活性成分的提取条件;并进行不同溶剂的吸收考察、专属性考察、DPPH线性考察、药材提取液线性考察、精密度试验、重复性试验、耐用性考察等方法学验证;以清除DPPH自由基的半抑制浓度(IC50)作为评价指标,对泻白散和方中3味药材的体外抗氧化活性进行考察。结果 地骨皮、甘草、桑白皮和泻白散提取液的IC50均值为0.31、1.24、1.49和0.91 g/L,泻白散提取工艺对方中药物抗氧化活性的保留均值为56%。结论 建立的抗氧化活性测定方法可用于泻白散及方中主药的抗氧化活性测定,为多维度评价中药和中药材质量提供新思路。 相似文献