Synthesis of singly-terminated ladder networks by multivariable array using homogeneous polynomials

This paper discusses a multivariable array whose elements are multivariable homogeneous polynomials which may have missing terms in any of the variables. This array permits one to obtain conditions for the realizability of a driving-point function or a transfer function as a resistively terminated low-pass ladder network. By reac- tance transformations, other forms of ladder structures can be obtained. The case of cascade-separable ladder networks is discussed in detail.     

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

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.     

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

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.     

A citation-based document retrieval system for finding research expertise

Current citation-based document retrieval systems generally offer only limited search facilities, such as author search. In order to facilitate more advanced search functions, we have developed a significantly improved system that employs two novel techniques: Context-based Cluster Analysis (CCA) and Context-based Ontology Generation frAmework (COGA). CCA aims to extract relevant information from clusters originally obtained from disparate clustering methods by building relationships between them. The built relationships are then represented as formal context using the Formal Concept Analysis (FCA) technique. COGA aims to generate ontology from clusters relationship built by CCA. By combining these two techniques, we are able to perform ontology learning from a citation database using clustering results. We have implemented the improved system and have demonstrated its use for finding research domain expertise. We have also conducted performance evaluation on the system and the results are encouraging.     

Some biochemical markers in various neoplasms: A multivariate analysis

The analysis of biochemical parameters in 162 patients with various neoplastic disorders along with 50 normal subjects showed significant rise in serum alkaline phosphatase and lactate dehydrogenase as compared to normal subjects. 21 patients with other monoclonal gammopathies which include infection and immunological diseases were also studied. Parameters such as serum calcium, uric acid, total protein, albumin and globulin were also analyzed in 42 (26%) cases of multiple myeloma, 27 (17%) cases of gastro-intestinal malignancies, 22 (14%) cases of urogenital malignancies, 11 (6%) cases of carcinoma breast, 4 (2%) cases of bone tumors, 21 (12%) cases of other monoclonal gammopathies, including 7 (4%) cases of infection and 14 (8%) cases of immunological diseases. The results indicate use of enzymes alkaline phosphatase and lactate dehydrogenase in neoplastic disorders.     

Unusual changes in colostrum composition in lactating Indian women having medical complications during pregnancy—A pilot study

Colostrum, the mammary secretion during first 2–4 days of lactation, provides all the essential components of nutrition and passive immunity required by the newborn. Pregnancy induced hypertension (PIH), glucose intolerance and anaemia are common medical complications observed during pregnancy in Indian women and their effects were studied on the composition of colostrum collected within 24 hours of delivery from lactating women included in the study. PIH during pregnancy significantly decreased colostrum IgA and total proteins, but showed a significant increase in K⁺ levels, where as women with glucose intolerance showed a significant decrease in total lipids and lactose and an increase in Na⁺ levels in colostrum compared to normal controls. The group with anaemia also showed a significant decrease in colostrum IgA and total protein levels when compared with the control group. Awareness about the changes that occur in the composition of colostrum during complicated pregnancies can be an important and useful tool for preventive and protective paediatrics.