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Biomedical subjects

S Gupta

Publications and source records attributed to S Gupta.

At least 1,369 records · Page 76Linked to original sources
PubMed1988

Cytokines: molecular and biological characteristics.

Cytokines are soluble molecules with many cells as the source of their origin and as targets for their actions. They are pleiotropic in their biological functions. Some cytokines are distinct with respect to their molecular structure yet they have overlapping biological properties (Interleukin 1 and tumor necrosis factors). Others are structurally distinct and often have contrasting biological activities (e.g. tumor necrosis factors and transforming growth factor-beta). In this article I have briefly reviewed the molecular and biological properties of four cytokines that appears to play an important role in the pathogenesis of certain immunoinflammatory disorders. It is also to be stressed that there are additional cytokines (e.g. granulocyte-monocyte colony stimulating factors, interleukin 2, interferons etc.) that could also play a role in the pathogenesis of immunoinflammatory disorders.

Animals↗
PubMed1988

Levels of dichlorodiphenyltrichloroethane and hexachlorocyclohexane in human adipose tissue of the Indian population.

Concentrations of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) were determined in 313 human omental fat samples collected from subjects from all five zones of India during 1977-1980. The median concentration of 2,2-bis-(p-chlorophenyl)-1,1-dichloroethylene (p,p'-DDE), total DDT, beta HCH, and total HCH were 3.4, 6.0, 1.3, and 1.9 mg/kg, respectively. The calculated national mean levels for DDT and HCH were 11.1 and 3.5 mg/kg, respectively. Although the values of DDT and HCH were not as high as those reported earlier, there is still a need for close monitoring of the bioaccumulation of these chemical residues in the Indian population.

Adipose Tissue↗
PubMed1988

Effect of K+ channel blockers on anti-immunoglobulin-induced murine B cell proliferation.

Ion channels play an important role in the transmission of signals across cell membrane in a variety of cell types. Recent studies indicate that normal murine splenic B lymphocytes express voltage gated K+ channels. In the present study, we examined the influence of K+ channel blockers 4 aminopyridine (4 AP) and tetraethyl ammonium, and Ca++ activated K+ channel blocker quinine on anti-immunoglobulin (anti-Ig)-induced B cell proliferation. The results show that ion channel blockers inhibited DNA synthesis in B cells induced by anti-Ig. 4 AP also inhibited protein synthesis but had no effect on the expression of surface immunoglobulin. 4 AP exerted its maximum suppressive effects on DNA synthesis when added within the first 24 hours after the onset of culture with anti-Ig. The inhibition of DNA synthesis by 4 AP was reversible upon its removal from culture. These studies show a role of K+ channels in B cell DNA and protein synthesis.

4-Aminopyridine↗
PubMed1988

Regulation of immune functions by human surfactant.

Human peripheral blood mononuclear cells (MNC) were incubated in vitro with highly purified human surfactant to examine its effect on various T cell functions. Surfactant inhibited DNA synthesis by lymphocytes in response to concanavalin A (Con A), phytohemagglutinin (PHA), and in the autologous mixed lymphocyte reaction (AMLR). In contrast, surfactant had no effect on pokeweed-mitogen (PWM, T cell-dependent B lymphocyte mitogen)-induced DNA synthesis or on interleukin-2 (IL-2) receptor expression on T cells activated with PHA, Con A or PWM. Furthermore, surfactant had either no effect or enhanced (depending upon the concentration of IL-2 used) the response of exogenous recombinant IL-2 on IL-2-dependent T cell line, In vitro addition of recombinant IL-2 corrected the suppressive effect of surfactant on the AMLR. These data show immunosuppressive effect of surfactant on T lymphocyte functions.

DNA↗
PubMed1988

Treatment of epidemic Kaposi's sarcoma with a combination of interferon-alpha 2b and etoposide.

A prospective clinical trial of concomitant interferon-alpha 2b and etoposide was conducted in 24 previously untreated patients with epidemic Kaposi's sarcoma. Eight of 21 evaluable patients (38%) achieved either a complete response (1 patient) or a partial response (7 patients). None of the responders had a prior history of opportunistic infection. Hematologic toxicity was severe, and 8 patients developed an opportunistic infection. The combination of interferon-alpha 2b and etoposide has modest activity, but no additive or synergistic activity was evident in the dose and schedule utilized in this study. The exact role for interferon-alpha in epidemic Kaposi's sarcoma, both as a single agent and in combinations, remains to be determined.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Cellular immune alterations associated with human insulin therapy.

To evaluate the immunogenicity of human insulin preparations, the treatment of 10 insulin-dependent diabetic patients was changed from purified porcine insulins to lente and regular semisynthetic human insulin (SSHI, N = 5) or NPH and regular biosynthetic human insulin (BHI, N = 5). Circulating levels of T lymphocyte subsets, in vitro responses of enriched mononuclear cells to mitogens and circulating insulin antibody measurements were performed before and during the 24 weeks of treatment. Insulin antibody levels did not change significantly in either human insulin treatment group. Circulating levels of Leu 1 and Leu 3 positive cells, identifying total and helper/inducer T lymphocyte populations respectively, and the Leu 3:Leu 2 (helper/inducer: suppressor/cytotoxic) T cell ration were all reduced (p less than 0.025) at eight weeks in the BHI treatment group. Cells identified with murine monoclonal antibody, Leu 7 defining a natural killer cell phenotype, were increased in the SSHI group at four weeks of study (p less than 0.05). There was a decreased pokeweed mitogen-induced proliferation of mononuclear cells in SSHI treated patients (p less than 0.01) at 12 weeks and both insulin treatment groups had increased responses to phytohemagglutinin (p less than 0.05) but not concanavalin A at 24 weeks. These data indicate that changes in the cellular immune system without associated changes in circulating anti-insulin antibody levels can be observed in patients whose treatment was changed from purified porcine to human insulin preparations. Thus, cellular immune responses may be more sensitive than humoral immune responses as indicators of immunological alterations to insulin preparations.

Adult↗
PubMed1988

Chemoprophylactic action of a substituted methyl benzimidazole carbamate against experimental nematode infections.

The prophylactic action of a substituted methylbenzimidazole carbamate was investigated against experimental nematode infections. The compound at the dose of 100 mg/kg x 1, i.m., protected hamsters against Ancylostoma ceylanicum for about 45 days and at 500 mg/kg x 1 protected rats against Nippostrongylus brasiliensis for 28 days. The uteri of female worms recovered from treated animals were devoid of ova so long the compound had considerable phophylactic action. In case of A. ceylanicum the compound exerted lethal action on L4 stage and in N. brasiliensis, mild action was noticed on L4 which became more pronounced on L5. The reference drugs, mebendazole and thiabendazole, had weaker prophylactic action.

Ancylostoma↗
PubMed1988

Action of praziquantel on calcium transport in Hymenolepis diminuta.

Effect of praziquantel on inward and outward Ca++ fluxes was investigated in Hymenolepis diminuta in glucose supplemented balanced electrolyte solution and under conditions of glucose/Mg++ deficiency. The 45Ca++ uptake in freshly isolated worms presented, generally, a biphasic kinetics. This comprised of an initial fast uptake phase, followed by a continued slower influx. The initial fast kinetics showed insensitivity to or slight stimulation by praziquantel depending on its concentration, and such stimulatory action was particularly prominent under Mg++ deficient condition (P less than 0.01). The subsequent slower 45Ca++ uptake was, however, markedly inhibited by the drug under both these conditions (P less than 0.01). Glucose starvation of the worms resulted in abolition of the fast 45Ca++ influx phase and uniform inhibition by the praziquantel without any indication of initial stimulatory effect (P less than 0.01). The extrusion of 45Ca++ from the label preloaded worms was stimulated by praziquantel under all the conditions investigated (P less than 0.01).

Animals↗
PubMed1988

Interferon responsiveness of natural killer cells in type I human diabetes.

Abnormally low circulating numbers and function of NK cells are associated with new onset type I diabetes. Since alpha interferon is a stimulator of NK function, enriched T and non-T lymphocytes were incubated with 0, 100 and 1,000 units/ml of recombinant alpha interferon (rIFN alpha) and natural killing against K562 and pancreatic islet cell targets was measured. The killing of K562 (1:20 target:effector ratio) cells by non-T cells incubated with 0, 100 and 1,000 units/ml of rIFN alpha in patients was decreased to 27% (p less than 0.014 vs control), 34% (p less than 0.001) and 39% (p less than 0.003) when compared to killing by normal control non-T cells (48%, 74% and 58% respectively). T cell mediated killing of K562 cells in patients was decreased to 3.9% (p less than 0.03), 5.3% and 6.6% (p less than 0.003) when compared to that of controls (8.7%, 10-8% and 22.6% respectively). Non-T cell mediated killing of islet cells (1:20 target:effector ratio) following treatment of effector cells with 0, 100 and 1,000 units/ml of rIFN alpha in patients was 19%, 27%, and 26% which was comparable to control subjects killing of 31%, 18% and 37% respectively. Similar data were obtained using T-cells as effectors. These data indicate that in new onset type I diabetes; (a) NK cell functional activity is diminished in both T and non-T lymphocyte subpopulations and (b) NK activity is suboptimally enhanced with rIFN alpha.

Adolescent↗