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Biomedical subjects

B Sewing

Publications and source records attributed to B Sewing.

6 recordsLinked to original sources
PubMed1993

Antagonism of alcohol-induced suppression of rat testosterone secretion by an inhibitor of nitric oxide synthase.

To examine whether nitric oxide (NO) mediates the suppression of testosterone secretion by alcohol (ethanol), adult male rats were pretreated with a NO synthase inhibitor, NG-nitro-L-arginine methyl ester (NAME), then treated with alcohol. Serum and testicular interstitial fluid (TIF) testosterone concentrations, serum luteinizing hormone (LH) concentrations, blood alcohol concentrations (BAC), and TIF volumes were measured 2 hr after alcohol treatment at a time of peak effects of alcohol and NAME on testosterone secretion. Pretreatment with NAME (30 or 100 mg/kg, subcutaneous) 30 min before alcohol treatment (0.5-3 g/kg, intraperitoneal) completely blocked the alcohol-induced suppression of testosterone secretion into the general circulation and into TIF without significantly altering blood alcohol concentrations (BAC) or TIF volumes. These results support the hypotheses that NO synthase inhibitors can antagonize alcohol-induced suppression of testicular steroidogenesis, that alcohol interacts with arginine-NO synthase systems that regulate testicular steroidogenesis, and that NO is involved in mediating alcohol's testicular and reproductive effects.

Amino Acid Oxidoreductases↗
PubMed1993

Opioid-induced suppression of rat testicular function.

The effects of opioids on testicular function were assessed in the rat through measurements of serum testosterone levels, testicular interstitial fluid (TIF) formation and TIF testosterone levels after morphine and opioid antagonist (naloxone, naltrexone) treatment. Serum and TIF levels of testosterone were significantly decreased 1 to 6 h after morphine (10 mg/kg) injection, and TIF volumes were decreased 2-3 h after injection morphine. Each of these decreases was dose-related. In contrast to the effects of morphine, the opioid antagonist naloxone increased TIF testosterone but did not alter TIF volumes. Moreover, the opioid antagonist naltrexone totally blocked morphine's effects on both testosterone secretion and TIF volume, suggesting that morphine's testicular effects were mediated by naltrexone-sensitive opioid receptors in the testes. The possible role of morphine-induced reductions in gonadotropin secretion in morphine's testicular effects was also examined. Morphine suppressed testosterone secretion and TIF volumes after pretreatment with human chorionic gonadotropin, which reverses morphine's suppression of luteinizing hormone (LH). Our results, therefore, indicate that morphine exerts effects on testicular function that are independent of its effects on LH. They furthermore support the hypothesis that both endogenous and exogenous opioids disrupt two major aspects of testicular function: Testosterone secretion and TIF formation. Because of the role of TIF in maintaining testicular function, our results suggest that opioid-induced changes in testosterone secretion into TIF and TIF formation may, at least in part, explain the well-established effects of opioids on reproductive endocrinology and function in the male.

Animals↗
PubMed1990

[Localization of nonpalpable breast lesions in intraoperative rapid-section diagnosis using a new procedure].

The author describes a simplified method for the radiological demonstration of non-palpable breast lesions in operative specimens. The specimen is x-rayed with a wire grid let into the lid of a small plexiglass box. The box with the tissue is then sent to the pathologist. By comparing the radiograph with the specimen, the pathologist is able to orientate himself and to examine the area in question.

Biopsy↗
PubMed1978

[The value of radiographic examinations of the thorax in acute myocardial infarction (author's transl)].

The degree of pulmonary congestion seen on chest radiographs taken in the intensive care unit was compared with the end-diastolic pulmonary artery pressure in 65 patients with recent transmural myocardial infarcts without cardiogenic shock. There was good correlation between the radiographic appearances and the end-diatrolic pulmonary artery pressure, so that the severity of left heart insufficiency could be diagnosed radiologically at an early stage. Errors were due to the time interval which must pass before the radiographic appearances approximate the haemodynamic changes. This resulted in a diagnostic "phase lag" (following a rise in end-diastolic pulmonary artery pressure) or in a post-therapeutic "phase lag" (after a fall in end-diastolic pulmonary artery pressure). Repeated examinations allow one to recognize changes in the haemodynamics. One should pay particular attention to the features of pulmonary venous and pulmonary arterial hy

Acute Disease↗