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Biomedical subjects

M Biswas

Publications and source records attributed to M Biswas.

At least 37 records · Page 2Linked to original sources
PubMed1995

Rapid detection of Vibrio cholerae 0139 in faecal specimens by coagglutination.

We compared the conventional culture method with the coagglutination (CoA) test for detecting V. cholerae 0139 antigen in a 4 h faecal enrichment culture. The CoA test reacted positively in all 13 culture positive stool specimens from patients with clinical cholera and negatively in all 23 culture negative specimens from non-diarrhoeal healthy controls. The test also did not show cross reaction with V. cholerae 01 antigen or with any of the enterobacterial antigens of the coliforms. The CoA test was found to be technically simple, rapid and reliable in diagnosing V. cholerae 0139 infection.

Agglutination Tests↗
PubMed1994

Changing bacteriological profile of cholera in Nagpur, 1991-93.

In Nagpur (Maharashtra) during the period 1991-93, Vibrio cholerae serogroup 01 predominated in 1991 (94.7%) and 1992 (86.4%) but significantly declined in 1993 (10.7%). Serogroups 02-0138 were infrequently encountered. A new strain V. cholerae serogroup 0139 emerged in 1993 and accounted for 89.3 per cent of the total vibrios isolated in the year. Replacement of the endemic 01 strain by the new 0139 strain was observed.

Cholera↗
PubMed1993

Atypical desmoid tumor of the abdomen: a case report.

Desmoids are rare lesions that are histologically benign but locally aggressive. These lesions should be considered in patients who present with abdominal masses, particularly if there is a prior history of familial polyposis. This case report describes a patient with an abdominal desmoid that demonstrated atypical features on computed tomography and correlative magnetic resonance images.

Abdominal Neoplasms↗
PubMed1992

Effect of bioamines on uptake of promastigotes of Leishmania donovani by hamster peritoneal macrophages.

Epinephrine and norepinephrine inhibit attachment of Leishmania donovani promastigotes to cultured hamster peritoneal macrophages. The inhibition was significant at catecholamine concentrations of 10(-4) and 10(-5) M and occurred when they were added to the cell mixtures, or after pre-treatment of either macrophages or parasites. Inhibition of attachment after pre-treatment was less marked than when the catecholamines were added to parasite-cell mixtures. Similar results were obtained with dibutyryl cyclic AMP, cholera toxin, theophylline, and cadaverine which raise intracellular cyclic AMP (cAMP). Pretreatment of parasites or macrophages with the bioamines elevated the intracellular cAMP concentration. It is suggested that the inhibitory effect on the host-parasite interaction is mediated through cAMP.

Animals↗
PubMed1991

Quantitation of insulin injection by high-performance liquid chromatography and high-performance capillary electrophoresis.

High-performance capillary electrophoresis (HPCE) was evaluated as a potential technique for the regulatory analysis of commercial dosage forms of insulin. A comparison was made to a liquid chromatographic analysis presently being proposed as an official monograph in the United States Pharmacopeia. The salient points of this comparison were accuracy, precision and ease of use. Both authentic (i.e. single blind, spiked) samples and commercial pharmaceutical formulations (injections) were examined. Chromatographic analyses of both commercial formulations and authentic samples were characterized by good precision, with accuracy being supported by results from authentic (spiked) samples. Conventional HPCE (by which is meant a non-micellar electrolyte used with an uncoated, unmodified fused-silica capillary) achieved reasonable accuracy, but less than impressive precision, when applied to authentic samples. When used for commercial formulations, this type of HPCE did not produce a level of accuracy suitable for regulatory purposes, even with the use of an internal standard.

Animals↗
PubMed1991

Isolation of a phosphoryl choline-binding protein from the hemolymph of the snail, Achatina fulica.

A phosphorylcholine-binding protein from the hemolymph of the snail Achatina fulica was purified to near homogeneity using a Sepharose phenylphosphorylcholine affinity column. The protein bound to the affinity column was eluted with 5 mM phosphorylcholine as a single symmetrical peak. The purified protein (400 Kda) contained 35-40% carbohydrate. On SDS-PAGE the protein separated into two bands of 20 and 24 Kda, and had a pI of 5.9. On immunodiffusion, antiserum to the snail phosphorylcholine binding protein did not cross-react against other phosphorylcholine binding proteins, like rat serum phosphorylcholine-binding protein (PCBP), limulus C-reactive protein (CRP), or human CRP. On pretreatment of the snail hemolymph with this antiserum, the hemagglutination titer of the hemolymph was markedly decreased. The purified snail phosphorylcholine binding protein agglutinated rabbit erythrocytes in the absence of divalent cation (Ca+2) but trace amount of Ca+2 increased its binding. The strongest inhibitor of the agglutination reaction was lactose, followed by melibiose and 2-deoxygalactose. The relationships of the snail phosphorylcholine binding protein to other hemolymph agglutinins and to CRPs are discussed in light of common phylogeny.

Animals↗
PubMed1990

Total serum glycosylated proteins in detection and monitoring of gestational diabetes.

The goal of this study was to determine whether serum glycosylated protein levels (i.e., fructosamine) can reliably screen for gestational diabetes and whether these levels are valid markers of short-term glycemic control in the third trimester of pregnancy. Ninety-seven pregnant women at 26-28 wk gestation were evaluated over 9 mo. HbA1c and serum glycosylated protein (serum fructosamine) were determined at the baseline venipuncture of the 100-g oral glucose tolerance test performed to detect gestational diabetes. Of the 97 women studied, 13 tested positive for gestational diabetes (National Diabetes Data Group criteria). There were significant differences in the fasting and 1-, 2-, and 3-h glucose values between nondiabetic and diabetic patients (P less than 0.005 at each time point). No difference was noted in the baseline serum glycosylated protein level (2.02 +/- 0.08 vs. 1.98 +/- 0.02 mM, NS) or HbA1c level (4.42 +/- 0.2 vs. 4.6 +/- 0.3%, NS) between gestational and nondiabetic patients. Diabetic patients were followed at 2-wk intervals, with serum glycosylated protein analysis, HbA1c, fasting glucose, and mean glucose determined by outpatient monitoring. Serum glycosylated protein correlated significantly to fasting blood glucose (r = 0.81, P less than 0.001) and mean outpatient glucose (r = 0.62, P less than 0.001) at the 2-wk follow-up visits. No correlation was found between HbA1c and fasting blood glucose (r = 0.11, NS) or mean outpatient glucose (r = -0.12, NS) during the follow-up period. The serum glycosylated protein level (serum fructosamine) is not a useful screening test for gestational diabetes. However, this assay shows potential as an objective marker of short-term control in evaluating the maternal glycemic state.

Adolescent↗
PubMed1987

The conformation of glycans of the oligo-D-mannosidic type, and their interaction with concanavalin A: a computer-modelling study.

The favored conformations of glycans of the oligo-D-mannosidic type have been determined by using empirical energy calculations. An interesting aspect is that the alpha-(1----3)-linked terminal D-mannose residue of the outer trimannosidic core fragment, in all the conformations which fall within 5 kcal.mol-1 of the global minimum, always lies close to the chitobiose core. These models are in general agreement with the available n.m.r. data. The probable modes of binding of these glycans to concanavalin A (Con A) were determined, by using a computer-modelling technique which identifies the positions for the different conformers of the carbohydrate in the binding site of Con A, based on stereochemical considerations. These studies showed that Con A can bind only to two of the three terminal D-mannose residues in these glycans, because the D-mannose residue which lies close to the chitobiose core is inaccessible for the binding of Con A. Of these two terminal D-mannose residues, the alpha-(1----6)-linked D-mannose may bind the more strongly. Furthermore, it is shown that the internal D-mannose residue will, at best, interact very weakly with the carbohydrate-binding site of Con A. These results rationalize well the available data on the binding affinity of these glycans to Con A. They further support the conclusion that the binding affinity of a glycan to Con A does not depend on the number in the glycan, of D-mannose residues which possess free 3-, 4-, and 6-hydroxyl groups, but, rather, on the accessibility of these residues to Con A.

Carbohydrate Conformation↗
PubMed1987

Effect of lapachol, a naphthaquinone isolated from Tectona grandis, on experimental peptic ulcer and gastric secretion.

Lapachol, a naphthaquinone isolated from the roots of Tectona grandis given at a dose of 5 mg kg-1 p.o. twice daily for 3 days was found to have an anti-ulcerogenic effect on subsequently induced experimental gastric and duodenal ulcers in rats and guinea-pigs. Its action appears to be associated with an effect on the protein content of gastric juice, and it reversed aspirin-induced changes in peptic activity, protein and sialic acid.

Animals↗
PubMed1981

The effect of pneumatic tourniquets on skeletal muscle physiology.

The effect of 3- and 5-hour pneumatic tourniquets on skeletal muscle physiology was investigated. Maximum isometric tension development, contraction and half relaxation times were measured in the muscles lying immediately under and distal to the tourniquet. On release of the tourniquet no consistent difference between control and experimental muscles was observed with respect to contraction and half relaxation times; however, there was a marked reduction in maximum isometric tension development. On the sixth day after release of a 5-hour tourniquet, isometric tension was reduced to 2--20 per cent of the control value in the distal muscle and to 40--60 per cent of the control value in the compressed muscle. Six days after a 3-hour tourniquet the compressed muscle tension was reduced to approximately 80 per cent of the control value whilst in the distal muscle, tension development varied from normal to 64 per cent of the control value. Thus it is shown that the effect on muscle contraction after a 3-hour tourniquet is not immediately reversed by the restoration of the blood supply. A reduction in muscle strength follows which may take a week or more to recover.

Animals↗
PubMed1980

Inducible N-acetyglucosamine-binding protein in yeasts.

Addition of N-acetylglucosamine (GlcNAc) to the medium elicits an immediate synthesis of a specific GlcNAc-binding protein in yeasts. Synthesis of this protein requires the continuous presence of GlcNAc as the inducer and is inhibited completely by the inhibitors of ribonucleic acid and protein syntheses. Furthermore, this protein has been partially purified from GlcNAc-grown Candida albicans cells and is quite distinct from the other induced enzymes of the GlcNAc catabolic pathway. A good correlation between the level of GlcNAc-binding protein and GlcNAc uptake capacity of the cells during induction was observed. Some of the sugars, e.g., N-acetylmannosamine, N-acetylgalactosamine, and glucose, had a similar competitive effect on the binding of GlcNAc as well as on its uptake. Furthermore, both the binding and uptake activities were sensitive to sulfhydryl reagents.

Acetylglucosamine↗
PubMed1980

Systemic and local effects of the application of a tourniquet.

The effect of the application of a tourniquet to a limb and the release of the accumulated metabolites have been investigated with reference to the acid-base level in the blood from the limb and in the right atrium. Investigations have been carried out experimentally in rhesus monkeys and observations have been made on patients undergoing reconstructive operations on the knee. The acidotic blood from the ischaemic limb produces little systemic effect. The limb recovers in approximately 40 minutes after a tourniquet has been in place for four hours. Three hours is recommended as a reasonable upper limit for the safe application of a pneumatic tourniquet.

Acid-Base Equilibrium↗
PubMed1979

Induction of N-acetylmannosamine catabolic pathway in yeast.

N-Acetylmannosamine kinase activity is absent from yeast cells grown on N-acetylmannosamine. However, other enzymes of the catabolic pathway, namely, N-acetylmannosamine-2-epimerase, N-acetylglucosamine kinase and glucosamine-6-phosphate deaminase are induced. In addition, a high affinity uptake system (permease) for the uptake of N-acetylglucosamine is synthesized under these conditions. The presence of either N-acetylmannosamine or N-acetylglucosamine as inducer is essential for the induced synthesis of these enzymes. The enzyme synthesis stops and their concentration in the cells declines rapidly as soon as inducer is removed from the medium. N-Acetyl-D-galactosamine can also induce all these enzymes except for N-acetylmannosamine-2-epimerase, suggesting the convergence of catabolic pathways for both the aminosugars at N-acetyl-D-glycosamine. Experiments with inhibitors of macromolecule synthesis suggest that the snythesis of RNA and protein is necessary for the induction of these cyzymes whereas the synthesis of DNA is not.

Acetylgalactosamine↗
PubMed1979

Necrotizing infection of scrotum.

Necrotizing infection of the scrotum (Fournier gangrene) rapidly spreads to adjacent skin with fever and toxemia and is life-threatening. Subcutaneous gas and a foul-smelling wet discharge from the skin are usually present. The infection is not cured with antibiotic therapy alone and requires immediate extensive debridement of all necrotic tissue. Repeated debridement each several days under general anesthesia is necessary until healthy granulation is present in the wound. Reconstruction with skin flaps or skin grafts shortens hospitalization and prevents the dense scar tissue and immobility of the tests that can occur with spontaneous epithelization.

Adult↗