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Biomedical subjects

V K Gupta

Publications and source records attributed to V K Gupta.

At least 19 recordsLinked to original sources
PubMed1998

Optical amplification of ligand-receptor binding using liquid crystals.

Liquid crystals (LCs) were used to amplify and transduce receptor-mediated binding of proteins at surfaces into optical outputs. Spontaneously organized surfaces were designed so that protein molecules, upon binding to ligands hosted on these surfaces, triggered changes in the orientations of 1- to 20-micrometer-thick films of supported LCs, thus corresponding to a reorientation of approximately 10(5) to 10(6) mesogens per protein. Binding-induced changes in the intensity of light transmitted through the LC were easily seen with the naked eye and could be further amplified by using surfaces designed so that protein-ligand recognition causes twisted nematic LCs to untwist. This approach to the detection of ligand-receptor binding does not require labeling of the analyte, does not require the use of electroanalytical apparatus, provides a spatial resolution of micrometers, and is sufficiently simple that it may find use in biochemical assays and imaging of spatially resolved chemical libraries.

Anisotropy↗
PubMed1998

Two B cell subpopulations have distinct recirculation characteristics.

This report describes two subpopulations of B cells in sheep. These subpopulations have distinct recirculation characteristics and tissue distributions. Phenotypically the populations are distinguished by their differential expression of the complement receptors, CD21 (CR2) and CD11b/CD18 (CR3). CD11b+ B cells are surface (s)IgMhi, co-express CD11c but are L-selectin negative. They populate the splenic marginal zone but are absent from splenic and ileal Peyer's patch (IPP) follicles and both afferent and efferent lymph compartments. Fluorescent tracing experiments showed that the CD11b+ B cells are non-recirculating as they did not appear in lymph after intravenous inoculation but are restricted to the blood and spleen. The CD11b-negative population expresses a conformational determinant of CD21 that is recognized by the monoclonal antibody Du 2-74. These cells are sIgMlo and co-express L-selectin. They populate the splenic and IPP follicles, are absent from the splenic marginal zone and are the only B cells in afferent lymph, efferent lymph and all lymph nodes. Fluorescence tracing experiments showed that the CD21 B cells are recirculating cells with their entry into efferent lymph being detectable by 16 h and peaking at 24-30 h. These data suggest that there are at least two lineages of B cells in the sheep with different phenotypic, functional and recirculation characteristics.

Animals↗
PubMed1997

A clinical review of the adaptive role of vasopressin in migraine.

Vasopressin is a naturally available neuropeptide that subserves important vasomotor, antinociceptive, behavior control, fluid and electrolyte balance, platelet aggregation and blood coagulation functions. This review focuses on the clinical phenomena of migraine that are likely to influence vasopressin bioavailability or efficacy as well as the modulating influence of vasopressin itself. As part of a complex homeostatic adjustment to stress and pain, the intricacies of vasopressin metabolism may have particular relevance to the pathophysiology of migraine.

Humans↗
PubMed1997

Eradication of H. pylori in a developing country: comparison of lansoprazole versus omeprazole with norfloxacin, in a dual-therapy study.

OBJECTIVES: Lansoprazole, a newer benzimidazole, is more potent than omeprazole in its anti-Helicobacter pylori effect in vitro. The present study was aimed at assessing its efficacy in a developing country. METHODS: Fifty patients were randomized to receive either lansoprazole or omeprazole, with norfloxacin for 2 wk; the ulcer healing rates, H. pylori eradication rates, and recurrence rates were compared over a 6-month period. RESULTS: Both lansoprazole and omeprazole were equally effective in inducing healing of ulcer (96.1 vs 95.5%, p > 0.05) and eradicating H. pylori (76.9 vs 63.9%, p > 0.05), with very low recurrence rates over a 6-month follow-up period. CONCLUSIONS: Either lansoprazole or omeprazole combined with norfloxacin is effective in eradicating H. pylori in a high percentage of cases of duodenal ulcer, with little difference between the two proton pump inhibitors.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1996

First-rib exostosis bursa.

We describe a case of exostosis bursa of the first left rib. Clinical features, investigations, and surgical management are described in detail.

Adult↗
PubMed1996

Identification of the sheep homologue of the monocyte cell surface molecule--CD14.

An ovine monocyte/macrophage cell surface antigen was recognized by three mouse monoclonal antibodies (mAbs) VPM65, VPM66 and VPM67. These mAbs also reacted with bovine cells. The antibodies immunoprecipitated a single, glycosyl-phosphatidylinositol-linked polypeptide of M(r) 55,000 which, when deglycosylated, was reduced to M(r) 53,000. They reacted strongly with peripheral blood monocytes, alveolar macrophages and peripheral blood granulocytes, and weakly with afferent lymph dendritic cells. They also reacted with macrophages in many different tissues but were non-reactive with lymphocytes. Competitive flow cytometry shows that these three mAbs recognize the same or a closely related epitope of a single antigen. An antigen-specific capture ELISA using the anti-human CD14 mAb (TUK4) revealed that all four mAbs associate with the same antigen. These data demonstrate that the mAbs react with the ovine homologue of the lipopolysaccharide (LPS)-LPS binding protein receptor, CD14.

Animals↗
PubMed1996

Identification of three myeloid-specific differentiation antigens in sheep.

The monoclonal antibodies submitted to the Third Workshop on Ruminant Leukocyte Antigens were analysed for their reactivity with sheep macrophage and monocyte populations. Initial analysis showed that, in addition to the anti-integrin mAbs, there were six mAbs that reacted with macrophages or monocytes but were unreactive on lymphocytes. Preliminary flow cytometry and immunohistology showed that there were three distinct groups of mAbs: Group 1 consisted of VPM65, VPM66 and VPM67; Group 2 consisted of just VPM64; Group 3 consisted of just VPM63. Further analysis demonstrated that Group 1 mAbs recognize the sheep homologue of CD14. Group 2 reacts with an M(r) 65,000-80,000 polypeptide possibly analogous to CD16 (Fc gamma RIII) and Group 3 reacts with an M(r) 40,000-42,000 doublet, probably identified as a minor isoform of sheep Fc gamma RII (CDw32). Another mAb (IL-A97) was similar in many respects to the Group 1 mAbs but there was a lack of data to confirm its specificity. All mAbs tested also reacted with cattle macrophages.

Amino Acid Sequence↗
PubMed1996

Cranial cystic epidermoid: report of two cases and review of the literature.

Intercranial epidermoid tumours are benign lesions of congenital origin that are potentially curable. Although computerized axial tomography (CT) and magnetic resonance imaging (MRI) are usually diagnostic, a few atypical features sometimes make pre-operative diagnosis difficult. Two cases of cystic epidermoids with peripheral ring enhancement are reported. Relevant literature has been reviewed.

Adult↗
PubMed1996

Should intellectual property be disseminated by "forwarding" rejected letters without permission?

Substantive scientific letter writing is a cost-effective mode of complementing observational and experimental research. The value of such philosophically uncommitted and unsponsored well-balanced scientific activity has been relegated. Critical letter writing entails the abilities to: maintain rational scepticism; refuse to conform in order to explain data; persist in keeping common sense centre-stage; exercise logic to evaluate the biological significance of mathematical figures, including statistics, and the ability to sustain the will to share insights regarding disease mechanisms on an ostensibly lower research platform. During peer review, innovative letter writing may share the occasionally unfortunate fate of innovative research. Rejected scientific letters do not automatically lose copyright. Periodicals with high letter loads will see some valuable contributions wasted, but that is the price for maintaining autonomy in scientific publication. The scientific community is an integrated whole that must respect the rights of authors at all levels. Unauthorised forwarding of rejected letters sets the dangerous precedent of justifying unjust means.

Biomedical Research↗