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Guggulsterone, a mixture of cis (E) and trans (Z) isomers (7∶3 w/w) was synthesized from 16-DPA. The isomers were separated by column chromatography and evaluated for cardioprotective and antioxidant activities. Myocardial necrosis induced by isoproterenol in rats caused marked increase in serum creatine phosphokinase and glutamate pyruvate transaminase. Simultaneously in ischemic heart, phospholipase, xanthine oxidase and lipid peroxides were enhanced following depletion of glycogen, phospholipids and cholesterol. Treatment with guggulsterone and its both isomers at the dose of 50 mg/kg po., significantly protected cardiac damage as assessed by the reversal of blood and heart biochemical parameters in ischemic rats. The cardioprotective activity of guggulsterone and of both the isomers were compared with that of gemfibrozil at the same doses. Guggulsterone and both the isomers at tested concentrations (5–20mM) inhibited oxidative degradation of lipids in human low-density lipoprotein and rat liver microsomes induced by metal ionsin vitro. The drug counteracted against the generation of superoxide anions (O2) and hydroxyl radicals (OH) in non-enzymic test systems. It is suggested that cardioprotective and antioxidant activities of synthetic guggulsterone and guggulsterone obtained from gum resinCommiphora mukul that contains isomers E & Z in the ratio of 46∶54w/w are the same.  相似文献   
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Mercury pollution and acute neurotoxicity of mercury is well known. The recent reports suggest the adverse effect of low dose mercury, though the available literature is still silent on its mechanism. This study was therefore undertaken to probe the effect of low dose methyl mercury induced heavy metal toxicity on free radical stress and its impact on behaviour of male albino rats. Male albino rats were exposed to 1 mg/kg body wt of methylmercury chloride for seven days, on day 8 they were tested for motor and memory functions. They were sacrificed later for biochemical estimations for rate of lipid peroxidation, nucleic acids, proteins in cerebrum, cerebellum and brain stem. There was an increase in the rate of lipid peroxidation showing methyl mercury induced free radical stress. The motor and memory functions demonstrated a clear decline, besides there was a lowering in the levels of nucleic acids and proteins as compared to controls. The results are important in view of recent reports that methyl mercury induced free radical stress results in early ageing and may serve as an initiating factor more specifically for neurodegenerative disorders like Alzeihemer's disease and dementias. The current findings support the notion that incorporating dietary antioxidants like curcumin, ascorbic acid and α-tocopherol in routine diet from early age may help combat the risk of developing such disorders in ensuing years.  相似文献   
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The correlation between antioxidant capacity and oxidative damage during aging has been reported in several tissues in different species. Glutathione-S-transferases (GST) can metabolise endogenous and exogenous toxins and carcinogens by catalysing the conjugation of diverse electrophiles with reduced glutathione (GSH). We observe a significant (P < 0.001) increase in plasma GST activity as a function of human age (r = 0.5675). A significant (P < 0.001) positive correlation (r = 0.8979) is observed between GST activity and total plasma antioxidant potential measured as ferric reducing ability of the plasma (FRAP). GST activity and red cell intracellular GSH also show a significant positive correlation (r = 0.7014). We hypothesize that the increased activity of plasma GST is a manifestation of increased generation of ROS and a concomitant decrease in the level of plasma antioxidant capacity during aging.  相似文献   
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GLOBALIZATION AND EDUCATION: COMPLEXITIES AND CONTINGENCIES   总被引:3,自引:0,他引:3  
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ABSTRACT

Schooling has long been studied for its role in class formation and reproduction, Australian government secondary schools have also traditionally been associated with ‘the local’ and with ‘nation building’. Some schools might now also be engaged with ideas of the ‘the global’ not only through policy practices and priorities, but also through the social dynamics of migration and movement. In globalizing times neither class formation nor schooling can be thought of simply in national terms. They are connected to globalizing forces yet cannot be divorced from their national specificity. We suggest that within Australia recent and historical emphases on skilled migration are pivotal to considering local connections to global middle class circuits. We argue for new approaches to studying the school experiences of global middle-class families and students, through a focus on transnational connectivities, generational dynamics, family and social life, rather than on more ‘culturalist’ approaches and national comparisons.  相似文献   
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This paper examines teachers' perceptions of their professionalism under conditions of educational reforms in government primary schools in Karachi, Pakistan. Conceiving teacher professionalism in terms of four dimensions (teacher efficacy, teacher practice, teacher leadership and teacher collaboration) it reports a quantitative survey research study of teachers in these schools, where educational reforms have been initiated. One conclusion from the study is that such teachers do perceive themselves as professionals—a finding that is counter to the often‐held beliefs about these teachers. The paper argues that it is important to regard teachers as professionals, capable of further enhancing their own professionalism, for improvement in the quality of teaching and learning in the government primary schools in Karachi.  相似文献   
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