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Anderson RA; Wallace AM; Kicman AT; Wu FC 《Human reproduction (Oxford, England)》1997,12(8):1657-1662
Administration of supraphysiological doses of testosterone to normal men
causes inhibition of spermatogenesis, but while most become azoospermic,
30-55% maintain a low rate of spermatogenesis. We have investigated whether
there are differences in endogenous androgen production, of testicular and
adrenal origin, which may be related to the degree of suppression of
spermatogenesis. Thirty-three healthy Caucasian men were given weekly i.m.
injections of 200 mg testosterone oenanthate (TE), 18 became azoospermic,
while 15 remained oligozoospermic. Urinary excretion of epitestosterone, a
specific testicular product, was reduced to <10% of pretreatment values,
with no differences between the groups. Similar results were obtained for
other markers of testicular steroidogenesis. Urinary and plasma adrenal
androgens were also reduced during TE treatment: a statistically
significant decrease in both (P < 0.001 and P < 0.05 respectively)
was seen in the azoospermic but not oligozoospermic responders. These
results suggest that testicular steroidogenesis is decreased to <10% by
the administration of supraphysiological doses of exogenous testosterone.
Differences in the degree of ongoing steroidogenesis in the testis do not
appear to account for incomplete suppression of spermatogenesis, thus
differences in androgen metabolism may underlie this heterogeneous
response. A small but significant reduction in secretion of adrenal
androgens was also detectable, the relevance of which is unclear.
相似文献
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Carrillo-Jimenez R Treadwell TL Goldfine H Buenano A Lamas GA Hennekens CH 《The AIDS reader》2002,12(11):501-3, 508
The brain natriuretic peptide (BNP) assay is a new, relatively inexpensive, and simple test that has the potential to be an early, cost-effective, and reliable marker for HIV-related cardiomyopathy. We report 1 case of HIV-related cardiomyopathy and 10 cases of of HIV infection with unknown heart disease in which we measured BNP levels and performed echocardiography. We found a significant inverse relationship between BNP and left ventricular function in these patients. Further basic and epidemiologic research on BNP measurement for the detection of HIV-related cardiomyopathy is needed to support these findings, which if confirmed, could have important clinical and public health implications. 相似文献
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Since exogenous hemin has been shown to exert a variety of stimulatory effects on erythroid cells, including the augmentation of hemoglobin synthesis, we determined its effect on early stages of erythroid development by employing clonal cells assays. The addition of hemin at a concentration of 2 X 10(-4) M to cultures of normal murine marrow substantially increased the observed number of primitive BFU-E, which was in contrast to its lack of an effect on more mature erythroid colony-forming cells. This cell-specific enhancement of primitive BFU-E resulted in marrow frequencies equivalent to or exceeding those reported in the presence of "burst-promoting activity." In the presence of hemin, the number of BFU-E was also observed to be linearly related to the number of cells plated at very low plating densities, and the cell titration curve was observed to extrapolate to the origin. The evidence suggests that hemin may be a primary growth regulator of early developmental stages of erythroid progenitor cells. 相似文献
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Aguilar D Skali H Moyé LA Lewis EF Gaziano JM Rutherford JD Hartley LH Randall OS Geltman EM Lamas GA Rouleau JL Pfeffer MA Solomon SD 《Journal of the American College of Cardiology》2004,43(11):2015-2021
OBJECTIVES: We assessed the influence of alcohol intake on the development of symptomatic heart failure (HF) in patients with left ventricular (LV) dysfunction after a myocardial infarction (MI). BACKGROUND: In contrast to protection from coronary heart disease, alcohol consumption has been linked to cardiodepressant effects and has been considered contraindicated in patients with HF. METHODS: The Survival And Ventricular Enlargement (SAVE) trial randomized 2231 patients with a LV ejection fraction (EF) <40% following MI to an angiotensin-converting enzyme inhibitor or placebo. Patients were classified as nondrinkers, light-to-moderate drinkers (1 to 10 drinks/week), or heavy drinkers (>10 drinks/week) based on alcohol consumption reported at baseline. The primary outcome was hospitalization for HF or need for an open-label angiotensin-converting enzyme inhibitor. Analyses were repeated using alcohol consumption reported three months after MI. RESULTS: Nondrinkers were older and had more comorbidities than light-to-moderate and heavy drinkers. In univariate analyses, baseline light-to-moderate alcohol intake was associated with a lower incidence of HF compared with nondrinkers (hazard ratio [HR] 0.71; 95% confidence interval [CI] 0.57 to 0.87), whereas heavy drinking was not (HR 0.91; 95% CI 0.67 to 1.23). After adjustment for baseline differences, light-to-moderate baseline alcohol consumption no longer significantly influenced the development of HF (light-to-moderate drinkers HR 0.93; 95% CI 0.75 to 1.17; heavy drinkers HR 1.25; 95% CI 0.91 to 1.72). Alcohol consumption reported three months after the MI similarly did not modify the risk of adverse outcome. CONCLUSIONS: In patients with LV dysfunction after an MI, light-to-moderate alcohol intake either at baseline or following MI did not alter the risk for the development of HF requiring hospitalization or an open-label angiotensin-converting enzyme inhibitor. 相似文献
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Chiang Jannifer O. Azevedo Rafael S. Justino Maria C. A. Matos Haroldo J. Cabeça Hideraldo L. S. Silva Sandro P. Henriques Daniele F. Silva Eliana V. P. Andrade Gabriela S. S. Vasconcelos Pedro FC. Martins Lívia C. Azevedo Raimunda S. S. 《Journal of neurovirology》2021,27(4):626-630
Journal of NeuroVirology - We describe two neurological cases of Oropouche virus infection in northern Brazil, where the virus is endemic but neglected as a pathogen. This study reiterates the... 相似文献