Alteration of predominant gastrointestinal flora and oxidative damage of large intestine under simulated hypobaric hypoxia.

Hypobaric hypoxia is an immediate and crucial starting mechanism of acute mountain sickness included with some non-specific gastrointestinal (GI) complications. To study the effect of hypoxia on GI microflora and its upshot to this system, male albino rats were exposed to 55 kPa (air pressure ~ 4872.9 m altitude) consecutively 30 days for 8 hours/day. The different indicator group of large intestinal microbial populations were enumerated and correlated with the levels of antioxidant indicators like catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), reduced glutathione (GSH) and oxidized glutathione (GSSG) of large intestinal epithelial cells. In addition, the histological study was performed by haematoxylin eosin (HE), periodic acid schiff staining (PAS) and scanning electron microscopy (SEM). It was observed that the density of total aerobes (104 folds) significantly (p < 0.05) decreased but the population of total anaerobes (209 folds) and Escherichia coli (125 folds) elevated after 30 days of hypoxic stress. The strict anaerobes like Bifidobacterium spp. (3 folds), Bacteroides spp. (134 folds), Lactobacillus spp. (7 folds) and other selected obligate anaerobes like Clostridium perfringens (40 folds), Peptostreptococcus spp. (21 folds) increased in respect to their control population. The growth direction index (GDI) of anaerobic populations was positive and correlated with gas formation aptitude. The activities of CAT and SOD in the large intestinal epithelia decreased significantly (p < 0.05) and GSH/GSSG pool turned into oxidized state with higher MDA (p < 0.05) formation. Histological study revealed the necrotized epithelial layer with higher lymphocytes infiltration in lamina propia accompanied by reduction of acidic mucins secreting goblet cells. From this experiment, it can be hypothesized that high altitude induced hypoxia manipulated the bacterial imprint and damaged the epithelial barrier of the large intestine which may cause systemic infection.

Tuning the interaction between carbon nanotubes and dipole switches: the influence of the change of the nanotube-spiropyran distance.

The non-covalent functionalization of carbon nanotubes with spiropyran molecules, serving as optically addressable dipole switches, is reported. Two kinds of pyrene-spiropyran-based dyads with spacers of different lengths resulting in different switch-tube distances were investigated. While both surfactants were able to form stable carbon nanotube suspensions, the different distances between the switch and the tube affected both of the components' optical properties. In the case of the shorter spacer, the nanotubes' luminescence as well as the merocyanine absorption band were red-shifted and furthermore, the rate of the merocyanine → spiropyran thermal back isomerization was decreased.

Purification and characterization of an endoxylanase from the culture broth of Bacillus cereus BSA1.

An extracellular xylanase from the fermented broth of Bacillus cereus BSA1 was purified and characterized. The enzyme was purified to 3.43 fold through ammonium sulphate precipitation, DEAE-cellulose chromatography and followed by gel filtration through Sephadex G-100 column. The molecular mass of the purified xylanse was about 33 kDa. The enzyme was an endoxylanase as it initially degraded xylan to xylooligomers. The purified enzyme showed optimum activity at 55 degrees C and at pH 7.0 and remained reasonably stable in a wide range ofpH (5.0-8.0) and temperature (40-65 degrees C). The Km and Vmax values were found to be 8.2 mg/ml and 181.8 micromol/(min mg), respectively. The enzyme had no apparent requirement ofcofactors, and its activity was strongly inhibited by Cu++, Hg++. It was also a salt tolerant enzyme and stable upto 2.5 M of NaCl and retained its 85% activity at 3.0 M. For stability and substrate binding, the enzyme needed hydrophobic interaction that revealed when most surfactants inhihited xylanase activity. Since the enzyme was active over wide range ofpH, temperature and remained active in higher salt concentration, it could find potential uses in biobleaching process in paper industries.

A novel Gymnema sylvestre extract stimulates insulin secretion from human islets in vivo and in vitro.

Many plant-based products have been suggested as potential antidiabetic agents, but few have been shown to be effective in treating the symptoms of Type 2 diabetes mellitus (T2DM) in human studies, and little is known of their mechanisms of action. Extracts of Gymnema sylvestre (GS) have been used for the treatment of T2DM in India for centuries. The effects of a novel high molecular weight GS extract, Om Santal Adivasi, (OSA(R)) on plasma insulin, C-peptide and glucose in a small cohort of patients with T2DM are reported here. Oral administration of OSA(R) (1 g/day, 60 days) induced significant increases in circulating insulin and C-peptide, which were associated with significant reductions in fasting and post-prandial blood glucose. In vitro measurements using isolated human islets of Langerhans demonstrated direct stimulatory effects of OSA(R) on insulin secretion from human ß-cells, consistent with an in vivo mode of action through enhancing insulin secretion. These in vivo and in vitro observations suggest that OSA(R) may provide a potential alternative therapy for the hyperglycemia associated with T2DM.

Role of clinical biochemistry laboratory in the diagnosis of diabetes mellitus.

Clinical biochemistry and laboratory help is needed at all stages of diagnosis of diabetes. Laboratory plays a key role in the management of diabetes and its complications like renal, metabolic, and others. Monitoring of treatment is also guided by regular blood sugar estimation and self-monitoring of blood glucose level.

Biochemical composition, lethality and pathophysiology of venom from two cobras-- Naja naja and N. kaouthia.

The cobras Naja naja and N. kaouthia are abundant in eastern and north-eastern India, accounting for maximum snakebite deaths. Here we report on variation in the composition of Naja kaouthia and N. naja venom from eastern India on corresponding differences in the severity of pathogenesis. These two venoms differ in chromatographic elution profile through Sephadex G-50 and enzyme activity, protein and carbohydrate contents associated with each fraction. The presence of greater amounts of basic phospholipase A2, L-amino acid oxidase and low molecular weight membrane active polypeptides in the N. naja venom makes it more toxic than N. kaouthia venom. A commercial polyvalent antivenom raised against N. naja venom inactivates lethality and variety of toxic effects of homologous venom more effectively than N. kaouthia venom.

Some biochemical properties of Russell's viper (Daboia russelli) venom from Eastern India: correlation with clinico-pathological manifestation in Russell's viper bite.

In the present study, some biochemical properties and pathological effects of Daboia russelli venom from Burdwan district of West Bengal, eastern India are presented. The clinical features of Russell's viper envenomation observed in patients admitted to Burdwan Medical College & Hospital are also reported. In vitro, whole venom exerts strong trypsin inhibitory, phospholipase A2 and procoagulant activities in addition to moderate adenosine monophosphatase and adenosine triphosphatase activities. Lethality (LD50) of this venom sample is 0.7 mg kg (i.v.) of mice. Significant local tissue damaging effects including edema, hemorrhage and necrosis are observed in experimental animal models. An increase in the level of serum enzymes, such as aspartate transaminase, alkaline phosphatase, creatine phosphokinase, lactate dehydrogenase after D. russelli venom injection in albino rats is indicative of cell or tissue damage. High incidence of intravascular hemolysis in addition to hemostasis, haemoptysis and haematuria are observed as the most prominent features of RVV envenomation from this part of India. The present study reinforces the hypothesis that variation in the venom composition of RVV from eastern India with respect to venom samples of Russell's vipers from other parts of India is responsible for the differences in the clinical manifestation in patients from eastern India.

Effect of oral supplementation of vitamin E on the hemolysis and erythrocyte phospholipid-splitting action of cobra and viper venoms.

In the present investigation, it was found that oral supplementation of graded amounts of vitamin E to volunteers increased the alpha-tocopherol content of the erythrocytes and decreased the susceptibility of the latter to the hemolytic action of cobra and viper venoms. Further, exogenous addition of graded amounts of alpha-tocopherol to the red cells, prior to the addition of either venoms, minimizes the venom-induced lysis and erythrocyte phospholipid splitting. It may thus be inferred that vitamin E, a fat-soluble antioxidant, plays an important role in reducing the hemolytic action of cobra and viper venoms.

The composition of Naja naja venom samples from three districts of West Bengal, India.

The variation in the composition of Naja naja venoms from three neighbouring districts of West Bengal, eastern India and the corresponding differences in the severity of pathogenesis due to venom composition variation are reported. These venom samples differ with respect to chromatographic elution profile and enzyme activity associated with each fraction. Presence of higher quantities of basic phospholipase and plasma protein hydrolase in the venom samples of Burdwan and Purulia make them more toxic than Midnapur venom sample. A polyvalent antivenom manufactured in western India was hardly effective in neutralizing the pathobiological manifestation of the venom samples from eastern India.

Lysosomal membrane stabilization by alpha-tocopherol against the damaging action of Vipera russelli venom phospholipase A2.

This investigation shows the membrane stabilizing effect of alpha-tocopherol against the damaging action of viper venom phospholipase A2 (PLA2). Liver lysosomal membranes from rats fed 100 mg and 200 mg alpha-tocopherol acetate per kilogram of diet were more resistant to damage by viper venom PLA2 compared with vitamin E-deficient rats. The membrane stabilizing effect of vitamin E is proposed to be due to the formation of a complex with the phospholipid hydrolysis products of the membrane.

Effect of dietary supplementation of vitamin E in partial inhibition of Russell's viper venom phospholipase A2 induced hepatocellular and microsomal membrane damage in rats.

The current investigation furnishes a good correlation between the alpha-tocopherol content of the liver and microsomes and corresponding inhibition of Russell's viper venom phospholipase A2 inflicted damage to them. Dietary supplementation of d1-alpha-tocopherol at a concentration of 100 mg and 200 mg per kg of diet displayed less damage caused by venom phospholipase A2 in sharp contrast to the vitamin E deficient rats. alpha-tocopherol due presumably to the formation of complexes with the phospholipid hydrolysis products of the membranes, plays a significant role in membrane stabilization.

Some serum enzymes in burns and their probable correlation with surgical shock--a prospective combined surgicobiochemical study.

Serum enzymes such as phosphohexoisomerase, aldolase and amylase were estimated in serum of 100 patients with thermal burn of different degrees. These enzymes were estimated at the time of admission, at 12th hour, 24th hour, 36th hour, 72nd hour, 7th day and 14th day. The patients with high serum levels of these enzymes till 72nd hour showed grave prognosis and serial measurements of these enzymes might help in predicting the outcome.

Frusemide-induced diabetes mellitus in insulin pretreated rabbits as an experimental model.

Single dose of frusemide 0.1 mg/kg orally was administered in 10 rabbits pretreated with soluble insulin 4 IU intravenously. Induction of diabetes after 24 h was confirmed by an increase in blood sugar and glucosylated haemoglobin and a decrease in serum insulin levels. Ten diabetic rabbits which received only frusemide without insulin pretreatment were used as controls, whereas equal number of insulin-pretreated rabbits receiving hydrochlorothiazide 250 mg/kg orally served as the positive control group. All biochemical parameters remained unaltered in the frusemide-treated test group as well as the positive control group after two weeks. The pancreatotoxic effect of frusemide may induce a stable hyperglycaemic state in rabbits which could lead to a useful diabetic model.

Epidemiology of Japanese encephalitis.

Seven hundred and sixty-two cases of Japanese Encephalitis (JE) were studied during the last 5 years (1985-1989) in relation to age, sex, religion, nutritional status, living habits, exposure to domestic animals and mosquitos, clinical profile, seasonal variation and mortality pattern. The maximum occurrence was in 1987-1988 and it showed a preponderance in males (51-82%). The disease is progressively decreasing in Muslims (3-7%) and gradually increasing in tribes (25-60%). Children in the age-group of 6-7 years (19-25%) were maximally affected and the disease was rare in infancy. The common features were coma, convulsions, neck rigidity and fever (88-97%). Gastrointestinal manifestations were rare (3.6%) but were associated with the highest mortality. About 80-95% had exposure to domestic animals directly or indirectly and 95% of the patients were not using mosquito nets. The CSF protein and sugar content were normal, with or without slight leucocytosis while the lymphocyte count was variable. The CSF and blood picture had no significant relation with clinical presentation and prognosis.

In vivo chloroquine resistant P. falciparum in Calcutta. A case report.

An in vivo chloroquine resistant P. falciparum malaria case is reported from Calcutta. The resistance level being R-1. The patient responded well to pyrimethamine and sulfadoxine combination, which appears to be the drug of choice in Calcutta for choloroquine resistant P. falciparum malaria as quinine is not available.