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Biomedical subjects

S Sehgal

Publications and source records attributed to S Sehgal.

At least 217 records · Page 12Linked to original sources
PubMed1984

Cadmium an inhibitor of lymphocyte transformation and stimulator of antibody-dependent cell-mediated cytotoxicity (ADCC) in rats: the role of zinc.

The effect of zinc (Zn) on the immunomodulatory properties of cadmium (Cd) was investigated in male Wistar rats. Animals were orally exposed to Cd and or Zn, by stomach tubing for 7 weeks. Response of splenocytes to phytohemagglutinin (PHA) and concanavalin A (Con A), was significantly increased by Zn. When exposed in combination with Cd, Zn restored the inhibitory effects of Cd on lymphocyte transformation. However, Cd significantly increased the antibody-dependent cell-mediated cytotoxic (ADCC) activity of the splenocytes on chicken red blood cells (CRBC). Zn had no effect on ADCC, nor did it modify the ADCC changes mediated by Cd.

Administration, Oral↗
PubMed1984

Effects on pregnancy in mice of passive immunization against ovine LH and human chorionic gonadotrophin.

Mice given daily i.p. injections of immunoglobulins against ovine LH on Days 3-7 of pregnancy were devoid of implantation sites on Day 8 whereas mice treated with antibodies to hCG had embryos of normal number and appearance on Day 8. These antibody treatments reduced the mean +/- s.d. serum progesterone concentrations from 65.4 +/- 15.3 ng/ml (control globulins) to 8.6 +/- 4.9 ng/ml (anti-LH) and 9.2 +/- 3.1 ng/ml (anti-hCG) on Day 8 and had no differential effect on serum oestrogen levels on Day 4. However, the mice treated with anti-hCG did not litter; resorption of the embryos took place between Days 10 and 14 of pregnancy. Indirect immunofluorescence and quantitative immunoenzymic assays showed the presence of anti-ovine LH and anti-hCG reacting antigens in the mouse feto-placental unit. On Day 6, the values of reacting antigens (mean +/- s.d. absorbance units/10 micron section of embryo) were 0.050 +/- 0.002 with control globulins, 0.059 +/- 0.002 with anti-hCG-Ig and 0.196 +/- 0.018 with anti-LH-Ig; the corresponding values on Day 12 were 0.075 +/- 0.009, 0.402 +/- 0.02 and 0.416 +/- 0.015. The quantitative disposition of the reacting antigens to the two types of anti-gonadotrophins seems to bear a temporal relationship to their respective antifertility action. The pregnancy terminating action of immunoglobulins to ovine LH (Days 6, 7 & 8) and hCG (Days 8, 9 & 10) was counteracted by administration of 2 mg medroxyprogesterone acetate on Days 6, 9 and 12, indicating the importance of progesterone in the maintenance of pregnancy in the mouse.

Animals↗
PubMed1983

Interactions of protein calorie malnutrition, malaria infection and immune responses.

The course of parasitaemia and certain immune responses in protein or calorie-deficient albino rats infected with Plasmodium berghei (NICD) were studied. Wide variations observed in the course of parasitaemia in protein-deficient animals were (a) prolonged prepatent period, short patent period with low parasitaemia (50% of animals), (b) short prepatent period and an inability to resolve the infection (14% of animals) and (c) no patent parasitaemia at any stage of observation (23.5% of animals). The calorie-deficient animals had significantly lower parasitaemia (P less than 0.05) compared with well fed animals. Protein deficiency resulted in depression of T-dependent immune responses in uninfected as well as P. berghei-infected animals. The outcome of the parasitaemia in protein- as well as calorie-deficient animals seems to be the combined result of deficiencies of certain essential nutrients, proteins and calories in the diet as well as the immune responses of the host.

Animals↗
PubMed1983

Role of macrophage-processed antigen in a Plasmodium berghei model.

The present study demonstrates that malarial parasite could be processed by macrophages in vitro to release 'super antigens'. These super antigens obtained from the peritoneal macrophages were more protective than those processed by the splenic adherent cells. BCG-stimulated macrophages were also able to process the antigens efficiently and these antigens were even superior to those obtained from the unstimulated macrophages. These modified antigens were potent inducers of DFPS to malarial antigens. It is thus concluded that parasite antigens, processed in vitro, carry specific immunogenic potential and are able to protect the recipients to parasite challenge.

Animals↗
PubMed1982

Lymphocyte subpopulation in acute viral hepatitis.

Studies of peripheral blood lymphocytes were performed in 41 patients with acute viral hepatitis, in grade III-IV coma; 16 patients were in the third trimester of pregnancy. There were significant reductions in absolute lymphocyte count and T cell number in patients who succumbed to the disease, when compared with those who survived. B cell counts were similar in the two groups and migration inhibition test with BCG antigen was normal. It is postulated that a decrease in the number of cells interacting in cell-mediated immune reactions is related to prognosis in acute viral hepatitis.

Acute Disease↗
PubMed1982

Immune complexes in Indian kala-azar.

Patients with Indian kala-azar were investigated for the presence of circulating immune complexes by the platelet aggregation test, complement deviation test, and polyethylene glycol precipitation test. Circulating antibodies were tested by the conventional indirect immunofluorescence test using leptomonad forms of Leishmania donovani and Crithidia luciliae. The serum complement level (C3) was measured using the Mancini technique. The results indicate that a large number of patients with Indian kala-azar carry circulating immune complexes with a significant lowering of complement levels in their sera. These complexes may be intimately linked with the depressed cell-mediated immune responses that are commonly observed in these patients. The study warrants a detailed immunohistopathological examination of the kidneys for the presence of tissue-bound complexes in chronic patients. Further, it is revealed that Crithidia luciliae and Leishmania donovani share common antigens and the former can be used as a substitute for determining anti-leishmania antibody by the indirect fluorescence assay.

Antigen-Antibody Complex↗