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Biomedical subjects

S K Gupta

Publications and source records attributed to S K Gupta.

At least 775 records · Page 43Linked to original sources
PubMed1983

Anticoccidial derivatives of 6-azauracil. 5. Potentiation by benzophenone side chains.

Attachment of p-benzophenone side chains at N1 was found to be one of the most effective modifications for enhancing the potency of 6-azauracil against a broad spectrum of coccidia in chickens. Compound 20 was about 1000-fold more potent than 6-azauracil. Structure-activity relationships paralleled those found in a previously reported series of related analogues containing diphenyl sulfide and sulfone side chains. Drug metabolism studies showed the ketones to be reduced rapidly to carbinols, which are the prevalent species in vivo.

Animals↗
PubMed1983

Zonal mitotic response in the adrenocortical tissue of the juvenile female duck to sex hormones.

The zonal response of the adrenocortical tissue to sex hormones was evaluated in the female duckling by mitotic (with colchicine) and histological studies. Estrogen (1 mg per bird daily for 10 days), progesterone (1 mg per bird daily for 10 days) or estrogen plus progesterone (0.75 mg plus 0.25 mg respectively per bird daily for 10 days) selectively inhibited mitosis in the central zone of the adrenocortical tissue. Histologically, estrogen or estrogen plus progesterone produced hypertrophy in the subcapsular zone, while progesterone caused atrophy in the central zone of the cortex. It is suggested that both the sex hormones have zonal action mitotically as well as histologically in the adrenocortical tissue of the female duckling.

Adrenal Cortex↗
PubMed1983

Deltoid contracture in children of central Calcutta.

Seventeen Muslim children of central Calcutta with postinjection fibrosis of the deltoid and abduction deformity are presented. The abduction deformity developed 3 to 7 years after receiving the first injection. Winging of the scapula and inability to bring the arm by the side of the body were the presenting symptoms in most cases. Excision of the main fibrotic band, which generally occurred in the intermediate fibres of the deltoid, along with incision of the thinner fibrotic bands when present, resulted in satisfactory correction of the deformity in 93.5% of the cases. The power in the deltoid remained Medical Research Council grade 5 in spite of loss of muscle bulk due to fibrosis.

Adolescent↗
PubMed1983

Analysis of cells of the mononuclear phagocyte series in experimental mycobacterial granulomas by monoclonal antibodies.

Two distinct types of granulomas were produced in the draining lymph nodes by immunizing guinea pigs with Mycobacterium bovis BCG or Mycobacterium leprae, as reported earlier (Narayanan et al., J. Pathol. 134:253-265, 1981). In the BCG-induced granuloma there is successful containment, killing, and degradation of the organisms with the presence of epithelioid cells and fibrosis. M. leprae, on the other hand, induces a granuloma where there is an absence of organization of the cells, failure to completely degrade the organisms, absence of epithelioid cells, and minimal fibrosis. By using a macrophage-specific monoclonal antibody and an anti-Ia monoclonal antibody and applying the immunoperoxidase, immunofluorescence, and fluorescence-activated cell sorter analysis techniques, the epithelioid cells of the BCG granuloma were found to have macrophage-specific antigen, but not detectable amounts of Ia antigen. This suggests that these cells have a close relationship to other cells of the mononuclear phagocyte series with which they share a common antigen. The absence of Ia antigen, on the other hand, suggests that epithelioid cells may not be involved in antigen presentation or other accessory cell functions where the presence of Ia antigen is crucial. The macrophages in the M. leprae-induced granuloma expressed both macrophage-specific and Ia antigens.

Animals↗
PubMed1983

Cell surface membrane protein changes during the differentiation of cultured human promyelocytic leukemia HL-60 cells.

The human promyelocytic leukemia cell line HL-60 was induced to differentiate in vitro by treatment with dimethyl sulfoxide or retinoic acid. Morphological maturation was accompanied by a total loss of transferrin binding and a 7-fold increase in the percentage of cells reducing nitro blue tetrazolium. Cell surface membrane proteins and glycoproteins were labeled with 125I by the lactoperoxidase-H2O2 or 1,3,4,6-tetrachloro-3 alpha, 6 alpha-diphenylglycoluril (Iodo-Gen) methods and analyzed by two-dimensional isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. A minimum of 12 cell surface proteins were unchanged, 3 proteins (Mr 95,000, 87,000, and 77,000) were lost, and up to 7 new proteins (Mr 270,000, 240,000, 150,000, 135,000, 58,000, 56,000, and 50,000) appeared during HL-60 cell differentiation. The kinetics of disappearance of one major labeled cell surface protein (Mr 95,000) within two days during treatment with retinoic acid correlated with the loss of cellular transferrin binding. This protein was identified as the transferrin receptor by affinity absorption of extracts of 125I-surface protein-labeled cells to transferrin-Sepharose beads. The affinity-purified component had molecular weights of 190,000 and 95,000 under nonreducing and reducing conditions, respectively, confirming its dimeric structure. Two-dimensional electrophoresis of cell surface membrane-labeled proteins of normal human granulocytes confirmed the absence of the transferrin receptor and identified cell surface proteins with molecular weight and pI values corresponding to three of the new cell surface proteins which appeared during HL-60 maturation. The most intensely labeled of these had a molecular weight of about 55,000, and was confirmed as being identical to the corresponding Mr 58,000 HL-60 cell surface membrane protein by one-dimensional peptide-mapping analysis. This prominent new Mr 55,000 to 58,000 protein increased continuously throughout retinoic acid-induced maturation and was identified as a major terminal myeloid differentiation cell surface membrane protein.

Cell Differentiation↗
PubMed1983

Variation amongst K562 cell cultures.

K562 cell cultures were obtained from three laboratories (A, B and C) outside our institution, and were designated according to source as K562A, K562B or K562C. The cultures obtained were constitutive or "wild type" K562 cell cultures, not cloned sublines. These cell cultures were compared with respect to growth kinetics, cell surface protein markers, surface antigens, cytogenetics and hemoglobin production. Morphology, growth kinetics in liquid suspension culture, cloning efficiency in soft agar culture, binding of anti-K562 monoclonal antibodies, and the majority of cell surface proteins were generally similar. In contrast, several important differences were observed: (1) hemoglobin synthesis induced by hemin was significantly different among K562A, B and C, K562A being most sensitive (P less than 0.05); (2) whereas more than 90% of K562A or C cells appeared to be Philadelphia chromosome (Ph1)-positive, less than 15% of K562B cells contained a Ph1; (3) membrane proteins (93 and 85 kilodalton) were identified in K562A, whereas only the 93 kilodalton protein was detected in K562B and neither of the proteins were detected in K562C. Our results indicate that K562 cells maintained in different laboratories can undergo tangible changes which may influence experimental results obtained in studies using these cells.

Autoradiography↗