Zinc: what is its role in biology?

Zinc is as common as iron in biology. It is usually thought to be a trace element required only for catalysis. Here it is shown that the role of zinc is much more fundamental not only in catalysis but in inhibitory control. There may well be several such control elements—calcium, iron, manganese, magnesium, and zinc.     

Effect of diabetic serum factor on polymorphonuclear leucocyte membrane hydrophobicity and particle internalisation

Membrane hydrophobicity and slalidase activity of normal Poly morphonuclear Leucocyte were significantly enhanced when incubated with DSF. As a consequence, internalisation ofE. coli andS. aureus (opsonised or unopsonised) were greatly dimnished, internalisation ofE. coli being higher in either category. Although, increase in hydrophobicity of the membrane correlated well with the time of decrease of particle internalisation (both at 30 min.), enhancement of sialidase activity did not coincide with the said alterations.     

Induction of diabetes by Streptozotocin in rats

The objective of this study is to induce experimental diabetes mellitus by Streptozotocin in normal adult Wistar rats via comparison of changes in body weight, consumption of food and water, volume of urine and levels of glucose, insulin and C-peptide in serum, between normal and diabetic rats. Intra-venous injection of 60mg/kg dose of Streptozotocin in adult wistar rats, makes pancreas swell and at last causes degeneration in Langerhans islet beta cells and induces experimental diabetes mellitus in the 2–4 days. Induction of experimental diabetes mellitus is indeed the first step in the plan of purification of pancreatic Langerhans islet cells of normal rats for transplanting under the testis subcutaneous of experimentally induced diabetic rats. Streptozotocin induces one type of diabetes which is similar to diabetes mellitus with non-ketosis hyperglycemia in some animal species. For induction of experimental diabetes in male adult rats weighted 250–300 grams (75–90 days), 60mg/kg of Streptozotocin was injected intravenously. Three days after degeneration of beta cells, diabetes was induced in all animals. The diabetic and normal animals were kept in the metabolic cages separately and their body weight, consumption of food and water, urine volume, the levels of serum glucose, insulin and C-peptide quantities in all animals were measured and then these quantities were compared. For a microscopic study of degeneration of Langerhans islet beta cells of diabetic rats, sampling from pancreas tissue of diabetic and normal rats, staining and comparison between them, were done. Induction of diabetes with Streptozotocin decreases Nicotinamide-adenine dinucleotide (NAD) in pancreas islet beta cells and causes histopathological effects in beta cells which probably intermediates induction of diabetes. In this study, we used Streptozotocin for our experiments in induction of experimental diabetes mellitus. After Induction of diabetes, consumption of food and water, volume of urine and glucose increased in the diabetic animals in comparison with normal animals, but the weight of body and the volume of insulin and C-peptide decreased in the diabetic animals. Sampling and staining of pancreas tissue of diabetic and normal rats showed that the Langerhans islet beta cells of diabetic rats have been clearly degenerated. In three days, Streptozotocin makes pancreas swell and at last causes degeneration in Langerhans islet beta cells and induces experimental diabetes. It also changes normal metabolism in diabetic rats in comparison with normal rats. Consumption of water and food, volume of urine, serum glucose increases in diabetic animals in comparison with normal rats but the levels of serum insulin, C-peptide and body weight decreases.     

The correlation between pertinence and rate of citation duplication in multidatabase searches.

The rate of citation duplication was examined in three databases: MEDLINE, BIOSIS, and LIFE SCIENCES COLLECTION. Duplicate citations were found to be more pertinent than unique citations. The duplicate citations came from a highly compact literature, while those from a single database were very widely scattered. The pertinent duplicated citations were more likely to be retrieved in searches that had more terms overall, had a higher percentage of thesaurus terms, and had terms which appeared in both title and abstract. These results suggest that the rate of duplication of citations in multidatabase searches may be used to rank output according to probable pertinence.     

Mathematical methods for modelling price fluctuations of financial times series

Statistical and Fourier analysis methods of time series representing fluctuations of stock market in general and Indian stock markets in particular are well known. This work is motivated by a recent paper by Guharay [Operations Research and Financial Engineering, Princeton University, Princeton, NJ, preprint, 2002] where he has studied trends in the S & P 500 for various time periods using wavelet tools. Our paper deals with a few Indian and Saudi stock prices and return fluctuation for a certain period of time. The main objective of the analysis is to understand the dynamics of the Indian and Saudi stock markets. We look for similarities, point of abrupt changes, normalized data, return, volatility, graph, pure and noise part, correlation lengths, and signal-to-noise ratio.     

Raised serum homocysteine levels in patients of coronary artery disease and the effect of vitamin B12 and folate on its concentration

Homocysteine(Hcy) has been implicated as a novel risk factor of Coronary Artery Disease (CAD) among Asian Indians, but many studies done in India failed to reveal any direct correlation. It has also been reported that Folic acid and Vitamin B12 levels inversely affect serum levels of homocysteine. In this study, we looked at the levels of homocysteine among patients with CAD. The effect of Vitamin B12, Folate and other risk factors on homocysteine levels were also evaluated. Mean homocysteine levels in cases (22.81±13.9, n=70) were significantly higher (p=<0.001) than the controls (7.77±7.3, n=70). However no statistically significant correlation could be deduced between homocysteine Vitamin B12, and Folate. Cumulative analysis have indicated an increase in homocysteine levels among patients with CAD with every additional risk factor.     

Troponin T and Heart Type Fatty Acid Binding Protein (h-Fabp) as Biomarkers in Patients Presenting with Chest Pain

Acute coronary syndrome (ACS) is a term for a range of clinical signs and symptoms suggestive of myocardial ischemia. It results in functional and structural changes and ultimately releasing protein from injured cardiomyocytes. These cardiac markers play a major role in diagnosis and prognosis of ACS. This study aims to assess the efficacy of heart type fatty acid binding protein (h-FABP) as a marker for ACS along with the routinely used hs-TropT. In our observational study, plasma h-FABP (cut-off 6.32 ng/ml) and routinely done hs-Trop T (cutoff 0.1 and 0.014 ng/ml) were estimated by immunometric laboratory assays in 88 patients with acute chest pain. Based on the clinical and laboratory test findings the patients were grouped into ACS (n = 41) and non-ACS (n = 47). The diagnostic sensitivity, specificity, NPV, PPV and ROC curve at 95 % CI were determined. Sensitivity of hs-TropT (0.1 ng/ml), hs-TropT (0.014 ng/ml) and h-FABP were 53, 86 and 78 % respectively and specificity for the same were 98, 73 and 70 % respectively. Sensitivity, specificity and NPV calculated for a cut-off combination of hs-TropT 0.014 ng/ml and h-FABP was 100, 51 and 100 % respectively. These results were substantiated by ROC analysis. Measurement of plasma h-FABP and hs-TropT together on admission appears to be more precise predictor of ACS rather than either hs-Trop T or h-FABP.     

The use and abuse of metatags

The web creates manyopportunities for encroachment on intellectualproperty including trademarks. Our principaltask in this paper is an investigation into anunusual form of such encroachment: theimproper use of metatags. A metatag is a pieceof HTML code that provides summary informationabout a web page. If used in an appropriatemanner, these metatags can play a legitimaterole in helping consumers locate information. But the ``keyword'' metatag is particularlysusceptible to manipulation. These tags can beeasily abused by web site creators anxious tobait search engines and bring scores ofvisitors to their sites. The law aboutmetatags is far from settled and many legalscholars are uncomfortable with the conclusionthat the unauthorized use of a trademark in ametatag represents infringement. How should weassess this practice known as ``spamdexing'' froma normative perspective? Is it commercial fairplay or something more sinister? We make thecase here that there are salient moral problemswith spamdexing since it exploits thereputational goodwill of trademark owners andconfuses consumers. It violates basic moralduties and it flouts the golden rule principle. Hence unauthorized use of a competitor'strademark in a metatag is not morallyacceptable.     

A review of ontology based query expansion

This paper examines the meaning of context in relation to ontology based query expansion and contains a review of query expansion approaches. The various query expansion approaches include relevance feedback, corpus dependent knowledge models and corpus independent knowledge models. Case studies detailing query expansion using domain-specific and domain-independent ontologies are also included. The penultimate section attempts to synthesise the information obtained from the review and provide success factors in using an ontology for query expansion. Finally the area of further research in applying context from an ontology to query expansion within a newswire domain is described.