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461.
The requirement for light in the anti-HIV-1 activity of hypericin was investigated. The hypericin concentration-dependence and light dosage-dependence of the reaction were measured. Under conditions in which hypericin caused substantial inactivation of HIV-1, there was a strict requirement for visible light. Only when the concentration of hypericin approached the cytotoxic level was there an apparent light-independent antiviral effect. This strict light-requirement for the antiviral effect could explain some of the apparently discrepant results reported by other workers. Furthermore if hypericin is contemplated for use in humans, the importance of light must be considered. 相似文献
462.
NI Perevodchikova MA Volkova VA Gorbunova LV Manziuk AF Marenich NB Smirnova 《Canadian Metallurgical Quarterly》1996,68(2):30-34
A cross-sectional five years retrospective community based study was conducted in 1990 to determine maternal mortality rate in Jimma town, south-western Ethiopia. The maternal mortality rate was found to be 4.02/1000 live births. The results of the study revealed that major causes of maternal mortality in this area are sepsis, eclampsia and abortion. Out of all deaths, more than 50% occurred after delivery of a child. Besides, the study indicates poor trend in following antenatal care and family planning among maternal mortality cases. Recommendations are made for detailed wide scale study to generate policy issues on the subject. 相似文献
463.
SJ Denardo NB Morris KJ Rocha-Singh GP Curtis DS Rubenson PS Teirstein 《Canadian Metallurgical Quarterly》1995,76(11):776-780
OBJECTIVES: To assess the relationship between obesity and strenuous physical activity in Saudi nationals living at high and low altitude. DESIGN: Cross-sectional randomized study. SUBJECTS: A total of 437 healthy adult Saudi nationals born and living permanently at high altitude (3150 m) and 468 healthy adult Saudi nationals born and living permanently at relatively low altitude 500 m). MEASUREMENTS: Body Mass Index (Weight (kg)/height (m2)) strenuous activity scores using Lipid Research Clinic Questionnaire. Resting radial pulse rate (beats/min). RESULTS: Strenuous physical activity was significantly and inversely associated with obesity in men at both high (chi 2 = 7.13, P < 0.05) and low (chi 2 = 6.14, P < 0.05) altitude but there was no clear trend for women at either altitude. The lack of association between strenuous physical activity and obesity in women was attributed to the low and homogeneous levels of strenuous physical activity. CONCLUSION: Strenuous physical activity should be encouraged as strategy directed towards weight reduction in obese as well as prevention of obesity in Saudi high and lowlanders. 相似文献
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MD Ennis P Stjernl?f RL Hoffman NB Ghazal MW Smith K Svensson H Wikstr?m SR Haadsma-Svensson CH Lin 《Canadian Metallurgical Quarterly》1995,38(12):2217-2230
A series of analogs of the potent and selective 5-HT1A agonist 8-(di-n-propylamino)-6,7,8,9-tetrahydro-3H-benz[e]indole-1-carbaldehyde (2b) (OSU191) was prepared in which the dipropylamino group was modified to bear a variety of substituents. These compounds were evaluated for both in vitro and in vivo effects, including the establishment of a receptor binding profile for these analogs at the 5-HT1A, dopamine D-2, dopamine D-3, 5-HT1D alpha, and 5-HT1D beta sites. Several of the analogs were evaluated for their biochemical effects in reserpinized rats, specifically with regard to in vivo changes in brain levels of 5-HTP and DOPA. Nearly all of the compounds prepared for this study were exceedingly potent at the 5-HT1A receptor, although most also displayed significant affinity for the dopamine D-2 receptor. A strong preference for the 5-HT1D alpha over the 5-HT1D beta receptor was also apparent. An analog bearing a butylglutarimide side chain, S-7k, was extremely selective for the 5-HT1A receptor. Although this compound possessed a Ki of 0.6 nM, it elicited only modest changes in 5-HTP brain levels. However, this compound did not appear as an antagonist when tested in a cyclic-AMP-based intrinsic activity assay. 相似文献
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The interaction between gold-labelled human transferrin (Au-HTF) with live meningococci after growth in vivo or in different in vitro conditions was examined by electron microscopy to localize and quantify the numbers of HTF-binding sites on the cell surface. It was clearly demonstrated that HTF binds to the surface of live meningococci (of different serogroups and serotypes) after growth in either iron-sufficient or iron-restricted cultures, although the degree of labelling was always higher (2- to 35-fold) in the latter case. The commensal Neisseria polysaccharea behaved similarly. Ultrathin sections showed that Au-HTF was localized predominantly on the outer membrane of the cells and vesicles, with hardly any internalization. Au-HTF labelling on meningococci was significantly reduced after incubation with unlabelled HTF or with rabbit antiserum containing antibodies against transferrin-binding proteins (TBPs), demonstrating the specificity of the interaction. These sera also blocked binding between HTF and outer membrane proteins on Western immunoblots. Direct evidence of the expression of the TBPs (Western blots) and localization of the HTF receptor (electron microscopy) on in vivo-grown meningococci was obtained from organisms derived without laboratory culturing from the cerebrospinal fluid of a patient. There was considerable cell-to-cell variation in the amount of labelling present on cells of the same sample (in vitro- or in vivo-grown organisms) and between different strains. The degree of binding varied with time of incubation of the cells with Au-HTF. The gold particles frequently formed discrete circles on the cell surfaces of the in vitro-grown organisms; these circles appear to be associated with outer membrane vesicle formation. The results show that the TBPs, which form part of the active components of the HTF receptor(s), are expressed in vivo and are surface exposed and immunogenic and that antibodies against them can interfere with the HTF binding of the meningococcal cells, which may affect iron utilization. This study further supports the concept of regarding the TBPs as future vaccine candidates. 相似文献
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