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Estrogen sulfotransferase (EST) catalyzes transfer of the sulfate group from phosphoadenosine phosphosulfate to estrogenic steroids. Since estrogen sulfates do not bind to the estrogen receptor with high affinity, EST can control the intracellular level of the receptor-active estrogens. Androgen action in the rat liver, as indicated by the androgenic induction of alpha 2u-globulin, is inhibited by low levels of estrogens. Thus, in situ estrogen inactivation by EST is expected to increase hepatic androgen sensitivity. During the lifespan of the animal, rat liver undergoes three distinct phases of androgen sensitivity, i.e. prepubertal androgen insensitivity, androgen sensitivity after approximately 40 days of age, and androgen insensitivity during senescence (greater than 750 days). EST in the liver is expressed only after puberty, when the liver becomes androgen sensitive. Furthermore, localization of EST and its corresponding mRNA within the lobular unit of the liver demonstrates that only androgen-responsive hepatocytes located around the central vein contain immunoreactive EST and its corresponding mRNA. These temporal and spatial correlations of EST expression and hepatic androgen sensitivity support the concept that steroid-inactivating enzymes play important roles in sex hormone action. 相似文献
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Adult worms of Acanthocheilonema viteae were found to be susceptible to the reactive oxygen intermediates (ROI) generated by the xanthine-xanthine oxidase (X-XO) system. The damage caused by this system was completely abolished by superoxide dismutase (SOD) and catalase but not by mannitol. The results, therefore, suggest that superoxide anions (O2-) and hydrogen peroxide (H2O2) alone or in combination might be toxic to the filariid. A. viteae exhibited the presence of an active enzyme system to protect itself against the oxidants. SOD and catalase were present in high levels of activities and appeared to constitute the major defence system. The role of glutathione peroxidase (GPx), on the other hand, seemed less important due to the weak activities of glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PDH). A. viteae also released SOD, catalase and GPx in the ambient medium, which appear useful in protecting the filariid against ROI generated by the host in the immediate surroundings of the parasite. Antifilarial agents, diethylcarbamazine (DEC) and 2,2'-dicarbomethoxylamino-5,5'-dibenzimidazolyl ketone (82/437) appreciably inhibited catalase and GPx of A. viteae. Inhibition of these enzymes appears to render the parasite prone to H2O2 toxicity leading to death. No adverse effect on antioxidant enzymes of liver, lungs and subcutaneous tissue of Mastomys natalensis recorded as a result of exposure to 82/437 suggests a non-toxic nature to the compound. 相似文献
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G J Gilson K J Knieriem J F Smith L Izquierdo M S Chatterjee L B Curet 《The Journal of reproductive medicine》1992,37(3):277-279
An infant was born to a woman who received intravenous esmolol for intrapartum supraventricular tachyarrhythmia. Despite the very short acting and cardio-selective beta-1 adrenergic blockade induced by that agent, neonatal effects can occur up to 48 hours after delivery. 相似文献
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S Chatterjee D K Chatterjee R H Jani J Blumbach B N Ganguli N Klesel M Limbert G Seibert 《The Journal of antibiotics》1992,45(6):839-845
Mersacidin is a new peptide antibiotic of the proposed lantibiotic family. It is active in vitro and in vivo against Gram-positive bacteria including the methicillin-resistant Staphylococci. Its in vitro activity is less than those of vancomycin and erythromycin but it shows much higher activity in the in vivo system than can be expected from the in vitro testing results. A water soluble potassium salt has been prepared which has an activity profile similar to that of mersacidin, but has better in vivo activity against Streptococcus pyogenes than the parent compound. 相似文献
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Endurance training was conducted on a group of 41 East Indian boys aged 10-14 years and was compared with 25 untrained boys of the same age. A continuous slow-running method was adopted for 12 weeks. The intensity of the training was 80-85% of maximum heart rate and frequency was 3 days per week. The boys were trained for a 1500-m event and therefore they covered three to five times their racing distance. For psychological reasons the training was carried out in a playground. The investigations included different physical and motor fitness tests: measurement of flexibility, agility, speed, leg muscle strength etc. Their performance times were also recorded before and after training. From statistical analysis we concluded that this particular type of training programme did not produce any detrimental effects on 10-14-year-old boys. On the other hand, this type of training did have some influence on improving physiological parameters in this age group of boys when compared with untrained boys of the same age. 相似文献
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Intestinal neuronal dysplasia (IND) has been reported as an innervation disorder that can present as isolated disease or may be associated with Hirschsprung's disease (HD). The interest in this disorder is growing as it mimics HD at clinical level but can be managed with a more conservative approach if an accurate diagnosis can be made. Many workers have tried to set up diagnostic criteria of this condition. But the importance of one criterion varied from one study to another. In our study we analysed seven cases of suspected innervation disorder that had undergone resection. A detailed histological study on these cases was performed and four of them were found to fulfill the diagnostic criteria of IND laid down by Kobayashi and his co-workers. These patients had hyperganglionosis, giant ganglia and ectopic ganglion cells in the lamina propria. In the other three cases some features were highly suggestive of the diagnosis of the IND and can be considered to be so if we follow other workers who have not given much importance to the simultaneous presence of all three criteria in a single case. 相似文献