Superoxide dismutase and catalase activities and their correlation with malondialdehyde in schizophrenic patients     

Rukmini M. S.  Benedicta D'Souza  Vivian D'Souza 《Indian journal of clinical biochemistry : IJCB》2004,19(2):114-118

Free radical mediated pathological processes may have a role in schizophrenia. Free radicals (oxy radicals, such as superoxide, hydroxyl ions and nitric oxide) cause cell injury, when they are generated in excess or when the antioxidant defense is impaired. Both these processes seem to be affected in schizophrenia. In this study we investigated erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities as antioxidant enzymes, malondialdehyde (MDA) as a sign of lipid peroxidation in schizophrenic patients. Activities of superoxide dismutase, catalase and malondialdehyde were greater in patients compared with the control group which may reflect increased oxidative stress in the brain tissue of schizophrenics. In the patient group erythrocyte SOD and CAT activities were weakly negative correlated with MDA concentration. These data reveal that antioxidant defense mechanisms might be impaired in schizophrenic patients. These findings also provide a theoretical basis for the development of novel therapeutic strategies, such as antioxidant supplementation.  相似文献   

Overexpression of Aldose Reductase Render Mouse Hepatocytes More Sensitive to Acetaminophen Induced Oxidative Stress and Cell Death     

Munzir M. E. Ahmed  J. A. S. Al-Obosi  H. M. Osman  M. E. Shayoub 《Indian journal of clinical biochemistry : IJCB》2016,31(2):162-170

Acetaminophen (APAP) a commonly used drug for decrease the fever and pain but is capable to induced hepatotoxicity at over dose. This study was carried out to investigate the effect of APAP on the expression of anti-apoptotic and antioxidative defense genes, and whether aldose reductase over-expressing plasmid capable to protect against APAP-induced oxidative stress and cell death. APAP treatment induced oxidative stress and hepatotoxicity, and significantly increased aldose reductase mRNA and protein expression in mouse hepatocyte (AML-12). Unexpectedly, AML-12 cells over-expressing aldose reductase augmented APAP-induced reduction in cell viability, reactive oxygen species (ROS) production, glutathione (GSH) depletion and glutathione S-transferase A2 expression. Moreover, over-expression of aldose reductase potentiated APAP induced reduction on proliferating cell nuclear antigen, B cell lymphoma-extra large (bcl-x_L), catalase, glutathione peroxidase-1 (GPx-1) and abolished APAP-induced B-cell lymphoma 2 (bcl-2) inductions. Further, over-expression of aldose reductase significantly abolished AMP activated protein kinase (AMPK) activity in APAP-treated cells and induced p53 expression. This results demonstrate that APAP induced toxicity in AML-12, increased aldose reductase expression, and over-expression of aldose reductase render this cell more susceptible to APAP induced oxidative stress and cell death, this probably due to inhibition AMPK or bcl-2 activity, or may due to competition between aldose reductase and glutathione reductase for NADPH.  相似文献   

Peter Westwick,The National Labs: Science in an American System, 1947–1974. Cambridge,Mass.: Harvard University Press, 2002     

Neushul  Peter 《Metascience》2003,12(3):443-445

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Leveraging global markets: Lessons from Alcoa Alumina     

Craig  Rosemary  Peter E.D.   《International Journal of Information Management》2007,27(6):432-437

Globalization has contributed to the dismantling of national boundaries, which have enabled firms to compete and conduct business on a wider scale [Held, D., McGrew, A., Goldblatt, D., & Perraton, J. (1999). Global transformations. Politics, economics and culture. Cambridge: Polity Press]. Firms can move freely between different markets using Internet-based technology. While access to such markets can provide firms with greater choice of suppliers and cost efficiencies, they need to be aware of challenges that can influence their business performance. With this in mind, we examine how these factors influenced Alcoa Alumina's drive to a global procurement platform through a global marketplace. The staged adoption process experienced at Alcoa Alumina offers a learning opportunity for other firms considering the transition to global marketplace.  相似文献   

Effect of <Emphasis Type="SmallCaps">l</Emphasis>-Thyroxine on Micronuclei Frequency in Peripheral Blood Lymphocytes in Clinical and Experimental Conditions     

Yogita S. Raut  Uma S. Bhartiya  Purushottam Kand  Rohini W. Hawaldar  Ramesh V. Asopa  Lebana J. Joseph  MGR Rajan 《Indian journal of clinical biochemistry : IJCB》2016,31(1):99-103

The aim was to study the genotoxic effect of high concentration of thyroxine (T₄) in vivo in peripheral blood lymphocytes (PBL) of the patients suffering from thyroid disorders. The effect was compared by performing in vitro experiments with addition of increasing concentration of T₄ (0.125–1 µM) in whole blood samples from healthy donors. Cytokinesis-blocked micronuclei (CBMN) assay method was used to assess the DNA damage in the PBL. The study included 104 patients which were grouped as control (n = 49), hyperthyroid (n = 31) and hypothyroid (n = 24). A significant increase in micronuclei (MN) frequency was observed in hyperthyroid patients when compared with the hypothyroid and euthyroid group thereby suggesting increased genotoxicity in hyperthyroidism (p < 0.001). A significant increase in MN frequency was observed at T₄ concentration of 0.5 µM and above when compared to lower T₄ concentrations (0.125 and 0.25 µM) and basal in in vitro experiments (p = 0.000). The results indicate that the T₄ in normal concentration does not exhibit the genotoxic effect, as observed in both the in vivo and in vitro experiments. The toxicity of T₄ increases at and above 0.5 μM concentration in vitro. Therefore acute T₄ overdose should be handled promptly and effectively so as to avoid the possible genotoxic effect of high concentration of T₄ in vivo.  相似文献   

Age related changes in lipid peroxidation and antioxidants in elderly people     

Akila V. Prashant  H. Harishchandra  Vivian D'souza  Benedicta D'souza 《Indian journal of clinical biochemistry : IJCB》2007,22(1):131-134

Advanced age is associated with an accumulation of free radical damage, which leads to physiological and clinical modifications. Age related changes resulting from free radical reactions include increasing levels of lipid peroxides, alterations in enzyme activities and greater osmotic fragility. The present study was conducted to estimate the level of lipid peroxidation product-Malondialdehyde and antioxidants Catalase and Glutathione in elderly people. An increase in lipid peroxidation and decrease in antioxidants was observed in normal elderly people. Highly significant increase in MDA and decrease in antioxidants was observed in elderly people when complicated with diabetes and hypertension. Supplementation of antioxidants may prevent further oxidative injury in elderly people.  相似文献   

In Search of a ‘Good Story’ for the History of Medicine     

Jonathan Simon 《Metascience》2005,14(3):427-429

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Status and Interrelationship of Zinc,Copper, Iron,Calcium and Selenium in Prostate Cancer     

Bhupendra Pal Singh  Shailendra Dwivedi  Urmila Dhakad  Ramesh Chandra Murthy  Vimal Kumar Choubey  Apul Goel  Satya Narayan Sankhwar 《Indian journal of clinical biochemistry : IJCB》2016,31(1):50-56

Deficiency or excess of certain trace elements has been considered as risk factor for prostate cancer. This study was aimed to detect differential changes and mutual correlations of selected trace elements in prostate cancer tissue versus benign prostatic hyperplasia tissue. Zinc, copper, iron, calcium and selenium were analysed in histologically proven 15 prostate cancer tissues and 15 benign prostatic hyperplasia tissues using atomic absorption spectrophotometer. Unpaired two tailed t test/Mann–Whitney U test and Pearson correlation coefficient were used to compare the level of trace elements, elemental ratios and their interrelations. As compared to benign prostatic tissue, malignant prostatic tissue had significantly lower selenium (p = 0.038) and zinc (p = 0.043) concentrations, a lower zinc/iron ratio (p = 0.04) and positive correlation of selenium with zinc (r = 0.71, p = 0.02) and iron (r = 0.76, p = 0.009). Considerably divergent interrelationship of elements and elemental ratios in prostate cancer versus benign prostatic hyperplasia was noted. Understanding of differential elemental changes and their interdependence may be useful in defining the complex metabolic alterations in prostate carcinogenesis with potential for development of element based newer diagnostic, preventive and therapeutic strategies. Further studies may be needed to elucidate this complex relationship between trace elements and prostate carcinogenesis.  相似文献   

Ethics and technology design     

Anders Albrechtslund 《Ethics and Information Technology》2007,9(1):63-72

This article offers a discussion of the connection between technology and values and, specifically, I take a closer look at ethically sound design. In order to bring the discussion into a concrete context, the theory of Value Sensitive Design (VSD) will be the focus point. To illustrate my argument concerning design ethics, the discussion involves a case study of an augmented window, designed by the VSD Research Lab, which has turned out to be a potentially surveillance-enabling technology. I call attention to a “positivist problem” that has to do with the connection between the design context and the use context, which VSD seems to presuppose, and I argue that it is necessary to clearly distinguish between the two, since the designers’ intentions do not always correspond with the users’ practice; in fact, the relation between design and use is very complex and principally unpredictable. Thus, a design theory must accept that foresight is limited to anticipation rather than prediction. To overcome the positivist problem, I suggest a phenomenological approach to technology inspired by Don Ihde’s concept of multistability. This argument, which is general in nature and thus applies to any theory of design ethics, is intended as a constructive criticism, which can hopefully contribute to the further development of design ethics.  相似文献   

Shareholder returns and the exploration-exploitation dilemma: R&D announcements by biotechnology firms     

Peter Mc Namara  Charles Baden-Fuller 《Research Policy》2007,36(4):548-565

We explore a financial returns dimension of the exploration-exploitation dilemma. Using 1277 R&D announcements by 178 listed bio-pharmaceutical firms, we examine whether investors are myopic along the continuum of exploration (patenting and preclinical trials) to exploitation (human clinical trials and NDA). We find that investors respond positively at every stage, but there are differences between small and large firms. For small firms exploration is favored, provided it is focused. For large firms, there is value in both exploration and exploitation. Projects which are part of an alliance are no more likely to generate abnormal returns. Policy implications are discussed.  相似文献