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951.
Murali Pagala N. V. Nandakumar S. A. T. Venkatachari Kadirimangalam Ravindran Bellamakonda Amaladevi Tatsuji Namba David Grob 《Muscle & nerve》1993,16(9):911-921
Fatigue mechanisms in normal intercostal muscle and muscle from patients with myasthenia gravis (MG) were evaluated by monitoring the compound muscle action potential (CMAP) and tetanic tension responses to repetitive nerve or muscle stimulation in vitro. When fatigue was induced by nerve stimulation at 30 Hz for 0.5 s every 2.5 s, about half of the original tension decreased after 30 min in normal muscle and 5 min in MG muscle. Analysis of the changes in area of CMAPs and tension indicated that impairment of neuromuscular transmission, muscle membrane excitation, and excitation-contraction (E-C) coupling and contractility accounted for 40%, 29%, and 31% of fatigue in normal muscle, and 83%, 0%, and 17% of fatigue in MG muscle. When fatigue was induced by muscle stimulation at 30 Hz, tension declined by a quarter after 30 min in normal muscle, but by a half after 17 min in MG muscle. Impairment of muscle membrane excitation and E-C coupling and contractility accounted for 58% and 42% of fatigue in normal muscle, and 22% and 78% of fatigue in MG muscle. Thus, fatigue of normal muscle is caused by impairment of at least four processes, and enhanced fatigue of MG muscle is caused by greater impairment of neuromuscular transmission, E-C coupling, and contractility. © 1993 John Wiley & Sons, Inc. 相似文献
952.
G. Dewasmes B. Bothorel A. Hoeft V. Candas 《European journal of applied physiology》1993,66(6):542-546
Summary Thermoregulatory sweating [total body (m
sw,b), chest (m
sw,c) and thigh (m
sw,t) sweating], body temperatures [oesophageal (T
oes) and mean skin temperature (T
sk)] and heart rate were investigated in five sleep-deprived subjects (kept awake for 27 h) while exercising on a cycle (45 min at approximately 50% maximal oxygen consumption) in moderate heat (T
air andT
wall at 35° C. Them
sw,c andm
sw,t were measured under local thermal clamp (T
sk,1), set at 35.5° C. After sleep deprivation, neither the levels of body temperatures (T
oes,T
sk) nor the levels ofm
sw, b,m
sw, c orm
sw, t differed from control at rest or during exercise steady state. During the transient phase of exercise (whenT
sk andT
sk,1 were unvarying), them
sw, c andm
sw, t changes were positively correlated with those ofT
oes. The slopes of them
sw, c versusT
oes, orm
sw, t versusT
oes relationships remained unchanged between control and sleep-loss experiments. Thus the slopes of the local sweating versusT
oes, relationships (m
sw, c andm
sw, t sweating data pooled which reached 1.05 (SEM 0.14) mg·cm–2·min–1°C–1 and 1.14 (SEM 0.18) mg·cm–2·min–1·°C–1 before and after sleep deprivation) respectively did not differ. However, in our experiment, sleep deprivation significantly increased theT
oes threshold for the onset of bothm
sw, c andm
sw, t (+0.3° C,P<0.001). From our investigations it would seem that the delayed core temperature for sweating onset in sleep-deprived humans, while exercising moderately in the heat, is likely to have been due to alterations occurring at the central level. 相似文献
953.
Black/white comparisons of deaths preventable by medical intervention: United States and the District of Columbia 1980-1986 总被引:4,自引:0,他引:4
Blacks in the US experience increased mortality (1113 versus 745 per 100,000 males; 631 versus 411 per 100,000 females) and decreased life expectancy (63.7 years versus 70.7 years for males; 72.3 years versus 78.1 years for females); compared to Whites. In an effort to determine if the excess mortality among Black Americans might be explained by differences in access or quality of health care services, we performed a race-specific analysis of conditions for which mortality is largely avoidable given timely and appropriate medical care. Using methodology proposed by Rutstein and Charlton, mortality due to 12 causes was evaluated including tuberculosis, cervical cancer, Hodgkin's disease, rheumatic heart disease, hypertensive heart disease, acute respiratory disease, pneumonia and bronchitis, influenza, asthma, appendicitis, hernias and cholecystitis. In the US, during 1980 to 1986, an average of 17,366 deaths and 286,813 years of potential life (YPLL) before age 65 were lost each year due to all 12 sentinel causes combined. Of these causes, hypertensive heart disease, pneumonia and bronchitis, cervical cancer and asthma accounted for the greatest number of deaths. The mortality rate for all 12 causes combined among Blacks was 4.5 times that of Whites. The highest relative rates among Blacks compared to Whites were observed for tuberculosis, hypertensive heart disease and asthma. The overall mortality rate in the District of Columbia for the selected causes was 3.7 times the national rate. Compared to national rates, statistically significant elevated rates in the District were observed for tuberculosis, hypertensive heart disease and pneumonia and bronchitis.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
954.
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956.
957.
The authors describe results of using endoscopic papillosphincterotomy in 100 patients with acute pancreatitis. Methods of endoscopic papillosphincterotomy and endoscopic papillosphincterowirsungotomy are presented. The effectiveness of the treatment was 96%. Operative procedures on emergency made up 1%, lethality-1%, complications-3% of the cases. 相似文献
958.
The USSR statistics on malignant neoplastic diseases of the urinary system and male sexual organs which comprised 5.7 per cent in the total mortality was presented for the first time. More than a 50 per cent increment in the death rate from these tumors was documented between 1975 and 1987. Annually, prostatic carcinoma is diagnosed in almost 10 thousand patients and cancer of the urinary bladder in 15 thousand patients. Maximal prevalence of the disease has been recorded in the Baltic republics, the Ukraine and Byelorussia. The detection rate of the aforementioned diseases, Stages I-II, is about 40 per cent. The estimate revealed that the total number of the registered oncological patients was 100 thousand persons. The problems in organization of the oncological care system, material and technical supplies and professional training should be considered. 相似文献
959.
960.