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91.
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
92.
Previous work showed that GABAergic differentiation in developing chick retina depends on insulin and cell interactions. Here, we investigated whether it depended on cell signaling mediated by retina cognin, a 50 kDa cell recognition molecule. Cognin mediates cell adhesion in vitro and occurs on retinal neurons that become both GABAergic and cholinergic. We investigated two markers of GABAergic differentiation: glutamate decarboxylase (GAD) activity and high-affinity GABA uptake. Both increase during differentiation of retinal neurons in culture and can be easily measured. We blocked cognin-mediated cell signaling with cognin antibody and found a reduction of the developmental increase in GAD activity in cultures of retinal neurons from 7 and 11 day chick embryos. There was no reduction of high-affinity GABA uptake. This suggested that cognin-mediated signaling was necessary for the normal developmental increase in GAD but not for high-affinity GABA uptake. These results contrasted with our previous observations on cholinergic differentiation in cultured retinal neurons. We found that cognin antibody blocked the normal developmental increase in choline acetyltransferase (ChAT) only if the cells were exposed before embryonic day 7. Thus, while both GAD and ChAT activity appear to be controlled by cell signaling involving cognin, the periods of developmental sensitivity for the two differentiation markers are different. Antibodies to other adhesion molecules, Ng-CAM, and N-cadherin, did not similarly affect GAD activity. Antibodies to laminin at a 10-fold higher concentration inhibited GAD activity only in early embryonic retina. Tests for protein synthesis and “housekeeping” enzyme activity demonstrated that the cognin antibody effect was selective for neuronal differentiation pathways. Thus, GABAergic differentiation in developing retina is sensitive to cell signaling mediated in part by cognin. 相似文献
93.
94.
Biji Bahuleyan Ankamma Rao Ari George Chacko Roy Thomas Daniel 《Journal of clinical neuroscience》2007,14(9):895-898
Chiari I malformation (CM) associated with a cervico-thoracic syrinx due to supracerebellar arachnoid cyst has not been reported in the literature. We report such a case, managed by fenestration of the arachnoid cyst and foramen magnum decompression (FMD), aiming to reduce the inferiorly directed pressure on the cerebellum and eliminate the craniospinal pressure dissociation respectively. Imaging done post-operatively showed upward displacement of the cerebellar tonsils with a decompressed craniovertebral junction and disappearance of the syrinx. 相似文献
95.
BACKGROUND: Twenty subjects were treated with either polidocanol (POL) or sodium tetradecyl sulfate (STS) to compare the efficacy and adverse sequelae of each agent. OBJECTIVE: To determine the safety and efficacy of two widely used sclerosing agents. METHODS: After the exclusion of saphenofemoral junction incompetency, each subject's leg veins were categorized by size (< 1, 1-3, and 3-6 mm in diameter). Each leg was then randomized to be treated with 0.5%, 1%, or 1% foam of POL or 0.25%, 0.5%, or 0.5% foam of STS according to vein size. An independent panel of four physicians, blinded to treatment, performed randomized photographic evaluations obtained pretreatment and 12 weeks post-treatment. Subject satisfaction index and overall clinical improvement assessment were also obtained. RESULTS: An average 83% improvement was noted for all vein sizes in all subjects with both POL and STS after a single treatment. Subjects were satisfied with treatment, regardless of the sclerosing agent used or the vein size treated. There was no statistically significant difference in adverse effects between each group. CONCLUSION: Both POL and STS are safe and effective sclerosing agents in the treatment of varicose and telangiectatic leg veins. Both are very tolerable and demonstrate similar post-treatment sequelae. 相似文献
96.
Diana Bell Yi-Jue Zhao Pulivarthi H. Rao Randal S. Weber Adel K. El-Naggar 《Head and neck pathology》2007,1(2):165-168
We present an adenoid cystic carcinoma of the base of tongue in a 48-year-old male with a restricted chromosomal alteration
by cytogenetic and spectral karyotypic analysis (SKY). SKY and G-banding analyses identified the t(6;14)(q25;q13) as the sole
structural aberration in all metaphases analyzed. This finding supports a critical role for this event in the development
of this tumor. The implications of chromosome 6q translocation in this case and in previously reported adenoid cystic carcinomas
are highlighted and discussed. 相似文献
97.
Chen Xinshan Zhang Yigu Rao Guangxun Huang Guangzhao 《Frontiers of Medicine in China》2007,1(3):338-342
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a kind of primary myocardial disease characterized by the regional
or global replacement of right ventricular myocardium by fatty and fibrolipomatous tissues. The ARVC, usually presenting with
different clinical manifestations and pathological changes, were mainly seen in young men and is one of the main causes of
sudden death in the young. Here two autopsied cases of Chinese men aged 30 and 23 years old who appeared healthy but died
suddenly while at work are reported respectively. One of the victims had extensive and severe pathological changes in his
heart involving the left ventricular wall as well as the ventricular septum and the right atrium. Not only was there a global
fatty and fibrolipomatous tissue replacement of the right ventricular myocardia, but also mild sarcoplasmic coagulation in
the myocardium and focal lymphocytic infiltration in the myocardial interstitium of the right ventricular wall. In addition,
slight atherosclerosis of the coronary artery and intimal thickening of the sino-atrial node were observed. It is believed
that there are no marked differences in the pathological changes of ARVC between Chinese patients and patients from western
countries. The etiology and pathogenesis of ARVC could not be explained by a single cause or factor and they are probably
related to various congenital and acquired causes or factors. 相似文献
98.
T S Rao J A Cler R P Compton M R Emmett S Mick E T Sun S Iyengar P L Wood 《Neuropharmacology》1990,29(3):305-309
Following intravenous administration, 1-aminocyclobutane-1-carboxylate (ACBC, 100 mg/kg), a N-methyl-D-aspartate (NMDA)-associated glycine receptor antagonist, was eliminated with a T1/2 of 5 min in mouse brain and 4 min in rat cerebrospinal fluid (CSF). 1-Aminocyclopropane-1-carboxylate (ACC), a NMDA-associated glycine receptor agonist, was found to have a T1/2 of less than 5 min in mouse brain. ACC and ACBC did not alter basal cerebellar cGMP. Glycine and D-serine increased cGMP, and 1-hydroxy-3-aminopyrrolidone-2 (HA-966), a glycine antagonist, reversed the D-serine-induced increases in cGMP. In contrast, ACBC did not reverse the D-serine-induced increases in cGMP. These data suggest that despite their brain bioavailability and marked potency at the glycine receptor in vitro, ACC and ACBC are rapidly inactivated and thus have limited in vivo utility. 相似文献
99.
S. Z. Qian Y. Z. Hu S. M. Wang Y. Luo A. S. Tang S. Y. Shu J. W. Zhou T. Y. Rao 《Advances in Contraception》1988,4(4):307-310
Tripterygium hypoglaucum (Lévl.) Hutch (TH) is a perennial used in Chinese traditional medicine for the treatment of rheumatoid arthritis and various skin disorders. One study showed that daily oral doses of TH significantly reduced the fertility of male rats without apparent toxicity. The effects of daily oral doses of TH on the fertility of men taking it for the treatment of rheumatoid arthritis were evaluated. Sperm concentration, motility and motility grade all were significantly reduced in the 13 men taking TH compared to 11 untreated controls. TH therapy did not affect testosterone, FSH, LH levels, and its antifertility effects appeared to be reversible.
Resumen Triperygium hypoglaucum (Lévl.) Hutch (TH) es una perenne usada en la medicina tradicional china para el tratamiento de artritis reumatoidea y de varios desórdenes de la piel. Un estudio demostró que orales diarias de TH reducían significativamente la fertilidad en ratas macho, sin toxicidad aparente. Se evaluaron los efectos de dosis diarias orales de TH en la fertilidad de hombres que le tomaban para el tratamiento de la artritis reumatoidea. La concentración de espermatozoides, la motilidad y el grado de motilidad, se encontraron significativamente reducidos en los 13 hombres tomando TH comparados con 11 controles no tratados. La terapia con TH no afectó los niveles de testosterona, FSH y LH y sus efectos antifertilidad parecían ser reversibles.
Resumé LeTriperygium hypoglaucum Hutch (TH) est communément utilisé en médecine traditionnelle chinoise pour le traitement de la polyarthrite chronique évolutive (PCE) et de divers troubles cutanés. Une étude a montré que l'administation quotidienne de doses orales de TH réduisait considérablement la fécondité de rats mâles sans provoquer de toxicité apparente. On a évalué les effets de doses quotidiennes administrées par voie orale sur la fécondité d'hommes atteints de PCE et traités au TH. La concentration, la motilité et le degré de motilité du sperme avaient significativement diminué chez 13 hommes traités au TH par comparaison avec 11 témoins non traités. Le traitement au TH n'a eu aucun effet sur les niveaux de testostérone, FSH et LH et ses effets anti-fécondants semblent être réversibles.相似文献
100.
In Wistar rats, the regional differences of pedal pressing rates of self-stimulation (SS) of lateral hypothalamus (LH) and substantia nigra-ventral tegmental area (SN-VTA) were assessed with electrodes implanted in both regions in each subject. Average of SS rates of SN-VTA sites was significantly higher than that of LH sites, tested with both sine wave and square wave types of stimuli. There was no significant difference in SS rates between males and females, and also in the females between different days of oestrus cycles. The high rates of robust SS observed in this study relative to SS rates reported in past literature were probably due not only to the placements of electrodes in the main substrates of SS, but also to the parameters of stimulus used (0.25 sec trains of sine waves through bipolar electrodes). 相似文献