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The authors studied the effects of 4-hydroxyandrostene-3,17-dione (4-OHA) on progesterone (P), 17 beta-estradiol (E2), and 20 alpha-hydroxy-4-pregnen-3-one synthesis and pregnenolone accumulation in cultured human midluteal cells. A dose-dependent inhibition with and without human chorionic gonadotropin (hCG) of E2 and P production was observed. The accumulation of pregnenolone was significantly enhanced three to fourfold by 4-OHA in this culture system, as compared with control value. In addition, a sevenfold increase on pregnenolone accumulation was observed in the presence of 4-OHA plus 10 IU of hCG as compared with control values and 2.2-fold as compared with the 4-OHA treatments. These in vitro findings indicate a direct effect of 4-OHA on luteal steroidogenesis. Nevertheless, the suppressive effect of 4-OHA on P and E2 production is located at different sites of the steroidogenic pathway. In addition, the results demonstrate that hCG in the presence of 4-OHA stimulated pregnenolone accumulation, suggesting that the inhibition of P synthesis is in some steps after the formation of pregnenolone. These data indicate that the actions of 4-OHA on P or E2 formation have different inhibitory mechanisms. 相似文献
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Neodymium: YAG laser treatment of persistent pupillary membrane 总被引:1,自引:0,他引:1
A 16-year-old girl had a cosmetically unappealing persistent iridopupillary membrane in the left eye. Her best corrected visual acuity was 20/60, but this improved to 20/40 with pupillary dilation. Neodymium: YAG laser membranectomy resulted in 20/20 vision. This is the first reported case of persistent pupillary membrane treated with the Neodymium: YAG laser. 相似文献
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V. van Casteren P. Leurquin A. Bartelds F. Gurtner V. Massari S. Maurice-Tison A.T. Vega R. Mak 《European journal of epidemiology》1993,9(2):169-175
This study describes a p. year international data collection on the demand pattern for HIV-antibody tests in general practice recorded by 6 sentinel networks in 5 European countries. The purpose of the recording was to evaluate the use of HIV-antibody testing by general practitioners and the demand for testing among the general population. Sentinel networks of general practitioners are a possible and available instrument for monitoring the perception of the HIV-test, and indirectly of the threat of the HIV-epidemic by the public and by the general practitioners (GPs). Differences were found between the countries in the frequency of testing, the person asking the test and the reason for testing. Possible explanatory factors, such as differences in the routine testing of specific groups, differences in the training and in the role of the GP, differences in the characteristics of prevention policy, are discussed. The European comparison also offers the opportunity to reflect on common medical practice in dealing with demands for HIV-tests. 相似文献
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Malignant fibrous histiocytoma of the lung 总被引:1,自引:0,他引:1
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E Del Villar P Vega C Gaule E Sanchez 《European journal of drug metabolism and pharmacokinetics》1990,15(4):279-285
Short or long term diabetes in female rats produced remarkable activation of aminopyrine N-demethylation, inhibition of oestrone and p-nitrophenol glucuronidation and no changes in morphine UDP-glucuronyltransferase activity in vitro. Km and Vmax for these reactions were determined. Insulin treatment partially antagonized diabetes activation of aminopyrine N-demethylation: it restored decreased UDP-glucuronyltransferase activities for oestrone and p-nitrophenol only in long term and short term diabetes, respectively. Insulin also markedly inhibited morphine glucuronidation. Triton X-100 also displayed a differential pattern of activation for the glucuronidation reactions in liver microsomes of diabetic rats. Results suggest that diabetes in female rats may increase the actual amount of enzyme protein for aminopyrine metabolism and to decrease that for oestrone and p-nitrophenol. 相似文献