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61.
62.
Hinsch E; Ponce AA; Hagele W; Hedrich F; Muller-Schlosser F; Schill WB; Hinsch KD 《Human reproduction (Oxford, England)》1997,12(8):1673-1681
Binding of mammalian spermatozoa to the zona pellucida and the induction of
the acrosome reaction are prerequisites for successful oocyte
fertilization. It has been postulated that xenobiotics that are released in
the environment as well as exposure to pharmaceutical medications may be
associated with reproductive problems in men and wildlife. Examining
physiological and non-physiological effects of particular compounds on
sperm functions requires high quality in-vitro test systems. We established
a reliable combined in-vitro test system with bovine gametes and evaluated
if aliquots of pooled post-thaw spermatozoa are suitable for examining
essential sperm functions. Using cryopreserved semen, the PSA-FITC/Hoechst
33258 staining procedure was applicable to evaluate the acrosomal status
and cell viability. In the bovine hemizona assay, hemizona indices revealed
no differences between cryopreserved and fresh semen. Treatment of
post-thaw bovine spermatozoa with progesterone (1 microM or bovine
follicular fluid (20%) induced the acrosome reaction from 12% (untreated
spermatozoa) to 25% (P < 0.001) and to 22% [corrected] (P < 0.01),
respectively. Incubation of both compounds (1 microM progesterone and 20%
follicular fluid) raised the percentage of acrosome-reacted spermatozoa to
30% (P < 0001). Our results demonstrate that cryopreserved semen can be
integrated into an in-vitro screening model for reproductive toxicology
testing. Pooled, cryopreserved bovine spermatozoa will thus permit
reproducible experiments for clinical and basic science purposes and may
also be applicable for the human system.
相似文献
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Predictors of smoking cessation: the Framingham Study. 总被引:3,自引:0,他引:3
K M Freund R B D'Agostino A J Belanger W B Kannel J Stokes 《American journal of epidemiology》1992,135(9):957-964
The relation of demographic, behavioral, and health-related variables to smoking cessation was studied in 1,178 women and 1,506 men cigarette smokers enrolled in the Framingham Heart Study. Smoking cessation was defined as abstinence from all tobacco products for at least 1 year. Proportional hazard models were used to identify baseline variables associated with long-term cessation. In order to identify factors predictive of cessation in the following 2 years, logistic regression models on person-examination data were used. Recent hospitalization and development of coronary heart disease were predictive of smoking cessation, while diagnosis of cancer or changes in pulmonary function were not. Overall, women were as likely to quit as men; however, women who smoked heavily were the least likely to quit. Secular trends were noted in men only; men were more likely to quit after the release of the 1964 Surgeon General's report on smoking. The relation of illness development and sex to smoking cessation should be considered in developing smoking cessation programs. 相似文献
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Precursors of sudden coronary death. Factors related to the incidence of sudden death. 总被引:13,自引:0,他引:13
Precursors of sudden death were sought in men--1838 civil servants in Albany, New York, and 2282 residents of Framingham, Massachusetts--under continuous surveillance for 16 years. In men 45-74 years old there were 234 deaths attributed to coronary heart disease (CHD) of which 109 occurred within one hour of onset of symptoms. More than half of all deaths due to CHD occurred outside the hospital and about 80 per cent of these were sudden. Most were unheralded by prior symptoms of CHD. Persons at high risk of death from CHD, including sudden death, can be identified long before the terminal unexpected catastrophe. The same precursive stigmata exist in persons subject ot coronary attacks whether or not immediately fatal. The risk of sudden death in these two populations was positively correlated with high blood pressure, the electrocardiographic pattern of left ventricular enlargement, obesity, and heavy cigarette usage. Sudden death is a common and possibly incidental expression of lethal coronary heart disease. The potential candidate for sudden death cannot be confidently distinguished from the individual who succumbs more slowly of myocardial infarction. The inescapable conclusion is that the prevention of sudden death requires the prevention of coronary attacks. 相似文献
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