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Biomedical subjects

A Mukherjee

Publications and source records attributed to A Mukherjee.

At least 217 records · Page 12Linked to original sources
PubMed1989

Exploration of antileishmanial activity in heterocycles; results of their in vivo & in vitro bioevaluations.

A total of 51 imidazoles, pyrroles, quinolines and isoxazolines compounds were screened for antileishmanial activity in vivo and in vitro, using Leishmania donovani as the test parasite. The screening revealed hitherto unknown antileishmanial activity in these heterocycles. Three of the compounds screened (one belonging to isoxazoline series and two from pyrrole series) showed significant anti-leishmanial activity, ranging from 86-91 per cent inhibition in hamsters. When tested in vitro, using macrophage amastigote culture system, these compounds showed inhibition of 62-78 per cent at 30 micrograms/ml concentration.

Animals↗
PubMed1989

An electron microscopic study of lymphatics in the dermal lesions of human leprosy.

The dermal lymphatic vessels in lepromatous and tuberculoid leprosy lesions were studied by light- and electron-microscopy. In the lepromatous patient, lymphatic vessels were seen in both intra- and peri-granulomatous areas. The lymphatic lining cells contained lipid droplets, lysosomes, and numerous pinocytotic vesicles. Cells bearing bacilli were only occasionally seen. In the tuberculoid cases, lymphatic vessels were seen only along the edges of the granulomas and the lining cells were less prominent. Inflammatory cells, both lymphocytes and histiocytes, were found traversing the walls of lymphatic vessels in both groups of patients. The results of the study confirm the continued and increased functioning of the lymphatic drainage system in dermal leprosy lesions, and indicates that it may be a major route for the clearance of lipids from the lipid-rich bacilliferous lesions in the lepromatous patient. The lymphatic pathway appears to be a minor pathway for the dissemination of Mycobacterium leprae in comparison with the blood vascular system.

Humans↗
PubMed1988

Kinetic regulation of hexokinase activity in a heterogeneous branched bienzyme system.

The kinetic behaviour of a heterogeneous branched bienzyme system of beta-D-glucose oxidase and hexokinase on glucose has been studied. In this sequence, hexokinase is inhibited by its product glucose 6-phosphate and also by D-gluconic acid produced from the parallel enzymic reaction of glucose oxidase. Effect of glucose concentrations on the product's distribution in branched pathway of the bienzyme system is dependent on the kinetic properties of hexokinase and glucose oxidase. Product inhibitions, which are also pH dependent, have a strong regulatory role on the reaction flux.

Gluconates↗
PubMed1988

Relative efficacy of short-term tests in detecting genotoxic effects of cadmium chloride in mice in vivo.

The ability of intraperitoneally administered cadmium chloride (0.42-6.75 mg/kg) to induce genotoxic damage in somatic and germ cells of mice was evaluated using chromosomal aberrations, sister-chromatid exchanges (SCE), micronuclei and sperm-head abnormalities as end-points. A significant increase in the frequency of chromosomal aberrations and SCEs was observed in almost all treated series when compared to the negative control. Micronucleus formation in polychromatic erythrocytes was not affected significantly except at the highest concentration used (6.75 mg/kg). Significant differences were observed in the frequency of sperm with abnormal head morphology at all concentrations tested except the lowest one. The clastogenic effects of cadmium chloride in both somatic and germinal cells are found to depend directly on the concentrations used.

Animals↗
PubMed1988

Effect of selenium on cadmium-induced chromosomal aberrations in bone marrow cells of mice.

Selenium, which is regarded as nature's antidote to heavy metal toxicities, was administered to mice. Salt solutions of cadmium chloride and sodium selenite were gavaged singly and successively, with or without a time gap of 1 h. Degrees of protection offered by this element against cadmium-induced toxic effects with special reference to chromosomal aberrations were assessed.

Animals↗
PubMed1988

Sister chromatid exchanges and micronuclei formations induced by sorbic acid and sorbic acid-nitrite in vivo in mice.

The in vivo induction of sister chromatid exchanges and micronuclei formations by acute treatment with different concentrations of sorbic acid and by nitrite, individually and in combination, was studied in bone marrow cells of mice. A significant increase in the frequency of sister chromatid exchanges was only observed with the three higher concentrations of sorbic acid when compared to a distilled water control. Sodium nitrite produced a significant increase at all doses tested. A combination of half the concentration of sorbic acid and of sodium nitrite gave an additive effect over that of sorbic acid or sodium nitrite alone. In the micronucleus assay, the highest dose of sorbic acid (150 mg/kg body weight) produced a significant increase in micronuclei formations compared to the distilled water control. Sodium nitrite alone induced significant numbers of micronuclei at all concentrations tested when compared to the negative control. However, a combination of half the concentration of sorbic acid and of sodium nitrite gave synergistic effects which could possibly be ascribed to the formation of certain genotoxic compounds in vivo.

Animals↗
PubMed1988

In vivo cytogenetic studies on mice exposed to Orange G, a food colourant.

Orange G, a monoazo dye, used as a food colourant, was evaluated with in vivo cytogenetic assays to determine its genotoxicity. Swiss albino male mice were exposed to Orange G through intraperitoneal injections. Bone marrow cells isolated from femora were analyzed for sister chromatid exchanges (SCE) and chromosome aberrations. The results showed that the incidence of SCEs and chromosome aberrations were significantly higher than controls at certain concentrations. 25 mg/kg of Orange G was found to be the minimum effective dose for the induction of both SCEs and chromosome aberrations. Orange G is thus found to be clastogenic and genotoxic in vivo in mice.

Animals↗
PubMed1988

Regional differences in the reactivity of guinea-pig airways.

Regional differences in the sensitivity of guinea-pig airways to cholinergic and beta-adrenoceptor stimulation as well as Schultz-Dale responses were studied in vitro. Carbachol and isoproterenol produced a 27% and 39% greater response, respectively, in the trachea as compared to the bronchus. Contractions to histamine in tracheal and bronchial tissues were significantly less than those evoked by carbachol (P less than 0.05); however, lung parenchymal strips did not show any difference in maximal contractility to these agonists. Responses to antigen in airways from sensitized guinea-pigs or responses to anaphylactic mediators, LTD4 and PGD2, in normal airways did not show any differences in maximum tissue contractility (trachea and bronchus). Among the airway tissues examined, lung parenchymal strips were more responsive to these mediators as compared to tracheal and bronchial tissues. Threshold and sub-threshold concentrations of LTD4 had no effect on tracheal and bronchial airway contractions to PGD2; however, PGD2-induced contractions of the lung parenchymal strip were significantly inhibited in the presence of LTD4 (P less than 0.0001). Our data suggest that: (1) considerable regional differences exist in the reactivity of guinea-pig airways; (2) the maximum responses of bronchial airways to cholinergic and beta-adrenergic stimuli appear less than that observed in the trachea; (3) small peripheral airways appear more responsive to some mediators of anaphylaxis than are the larger central airways. Therefore, it would appear that the trachea and bronchus are more responsive to cholinergic stimuli, while the lung parenchyma is more responsive to PGD2, LTD4 and also to in vitro anaphylaxis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Anorectal melanoma.

Four cases of anorectal melanoma are presented. The authors believe that this is the first report of the occurrence of this tumour in Malays. Advanced disease at initial presentation accounts for the poor prognosis observed in this series. Surgery remains the principal treatment modality, although controversy exists regarding optimal extent of resection.

Adult↗
PubMed1987

Regulation of fructose uptake and catabolism by succinate in Azospirillum brasilense.

Fructose uptake and catabolism in Azospirillum brasilense is dependent on three fructose-inducible enzymes (fru-enzymes): (i) enzyme I and (ii) enzyme II of the phosphoenolpyruvate:fructose phosphotransferase system and (iii) 1-phosphofructokinase. In minimal medium containing 3.7 mM succinate and 22 mM fructose as sources of carbon, growth of A. brasilense was diauxic, succinate being utilized in the first phase of growth and fructose in the second phase with a lag period between the two growth phases. None of the fru-enzymes could be detected in cells grown with succinate as the sole source of carbon, but they were detectable toward the end of the first phase of diauxie. All the fru-enzymes were coinduced by fructose and coordinately repressed by succinate. Studies on the effect of succinate on differential rates of syntheses of the fru-enzymes revealed that their induced syntheses in fructose minimal medium were subject to transient as well as permanent (catabolite) repression by succinate. Succinate also caused a similar pattern of transient and permanent repression of the fructose transport system in A. brasilense. However, no inducer (fructose) exclusionlike effect was observed as there was no inhibition of fructose uptake in the presence of succinate with fructose-grown cells even when they were fully induced for succinate uptake activity.

Culture Media↗