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Biomedical subjects

R Chander

Publications and source records attributed to R Chander.

46 records · Page 3Linked to original sources
PubMed1989

Hepatic low density lipoprotein receptor binding and lipid profile in Mastomys natalensis during Plasmodium berghei infection.

Plasmodium berghei infection to Mastomys natalensis showed hyper beta-lipoproteinemia. The increase in serum cholesterol is associated with decreased uptake of low density lipoprotein (LDL) by the liver through receptor mediated endocytosis. The membranes prepared from infected M. natalensis exhibit up to 50% decline in high affinity binding sites for human 125I-LDL. Significant increases in serum lipids, cholesterol, triglyceride and lipid peroxide (LPO) contents of liver membrane were observed. Effects of lipid constituents and LPO content of liver membrane in relation to LDL catabolism and other possible mechanisms have been explained.

Animals↗
PubMed1987

Mechanisms of acquired resistance in mouse typhoid.

A polyvalent radiovaccine of Salmonella was shown to induce protective immunity in mice. The results revealed that the immunized mice progressively eliminated the challenged organisms and no Salmonella could be isolated after a period of 21 days. In contrast, Salmonella grew in the control mice and reached levels of 10(8) to 10(9) cfu/spleen resulting in the death of animals. Sera from both control and the immune mice were found to lack bactericidal activity. It was further observed that the vaccine induced delayed type of hypersensitivity and that antibody production as measured by bacterial agglutination and passive hemagglutination were low in response to the vaccine. However, the phagocytic activity of the reticuloendothelial system was considerably enhanced by the immunization. The results of experiments with immunosuppressed mice suggested the role of thymus derived (T) lymphocytes in the protection.

Agglutination Tests↗
PubMed1986

Role of thymus-derived lymphocytes in acquired immunity to salmonellosis in mice.

The relative role of thymus-derived (T-) lymphocytes and bone marrow-derived (B-) cells in acquired immunity to salmonellosis was examined in mice. The results demonstrate that the protective capacity of the donor immunized mice could be passively transferred to the recipient mice by spleen cells but not with peritoneal exudate cells or sera. A high cell number of spleen cells (2 X 10(8)/mouse) were required before passive transfer of immunity could be obtained. Of the T-lymphocytes and B-cell populations of spleen cells, T-cells from immune mice were effective in conferring protection to the recipient mice.

Animals↗
PubMed1981

Induction of resistance to ascites tumor in mice with MFS-180 cells treated with glutaraldehyde, lipopolysaccharide, and concanavalin A.

Immunization with MFS-180 vaccine prepared in the presence of glutaraldehyde (0.05%), lipopolysaccharide (LPS) (100 micrograms/ml), and concanavalin A (Con A) (200 micrograms/ml) could protect Swiss mice against a subsequent challenge by 1 X 10(6) MFS-180 cells. The sequence of attachment of LPS and Con A to glutaraldehyde-treated cells as found to determine the efficacy of the vaccine. LPS coupled with glutaraldehyde-treated cells before Con A could effect 100% survival, while LPS attached after Con A treatment to glutaraldehyde-treated cells showed only 60% survival. The protection was specific for syngeneic cells.

Aldehydes↗
PubMedDate not supplied

(Patho)physiologic pathways to drug targeting: artificial viral envelopes.

The goal of this study was to exploit molecular recognition of cell surface receptors by viral surface glycoproteins as a means for the selective intracellular delivery of macromolecules. To accomplish this, artificial viral envelopes (AVE) resembling the human immunodeficiency virus-1 (HIV-1) were designed as a model system. Recombinant HIV-1 surface glycoprotein gp160 (HIV-1 rgp160) was inserted in the artificial envelope by a two-step detergent dialysis process. The artificial HIV-1 envelope recognized the CD4 cell surface receptor. FITC-dextran and ricin A were employed as model macromolecules as they cannot passively diffuse across cell membranes. Selective transfer of FITC-dextran encapsulated in HIV-1 rgp160 AVE into a CD4-positive cell line (REX-1B) versus a CD4-negative cell line (KG-1) was demonstrated. Ricin A at concentrations as low as 2 ng/ml arrested cell growth of CD4-positive MOLT-4 cells, whereas 8 ng/ml ricin A in solution had no effect on cell growth. The arrest of cell growth was reverted in the presence of excess anti-gp120 monoclonal antibody. Naked envelopes (without HIV-1 rgp160 inserted) were also found to interact with cells and transfer material, although less efficiently and in a non-specific manner. Viral mimicry using AVE may be a means for targeted intracellular delivery of peptides, proteins, enzymes, toxins, oligodeoxynucleotides, gene constructs, and other non-diffusive, labile or toxic macromolecules.

CD4 Antigens↗
PubMedDate not supplied

Stimulation of low density lipoprotein receptor activity in liver membrane of guggulsterone treated rats.

Chronic feeding of guggulsterone to rats showed hypolipidaemic activity in blood serum and liver membrane lipids. The decrease in serum cholesterol is associated with enhanced uptake of LDL by the liver through receptor mediated endocytosis, located on the surface of the cell membrane. In the present communication it has been shown that membranes prepared from liver of guggulsterone treated rats exhibit up to 87% increase in binding sites for human 125I-LDL. Significant decrease in lipid levels of serum as well as of membrane were observed. Lipid lowering activity of the drug in relation to LDL catabolism and other possible mechanisms have been explained.

Administration, Oral↗
PubMedDate not supplied

Epidemiology of hepatitis E and A in Ludhiana.

AIM: To study the epidemiology of hepatitis E and A in Ludhiana. METHODS: A retrospective analysis of laboratory data of the year 2001 was done, to study the epidemiology of hepatitis E and A in Ludhiana in relation to prevalence, age, sex, area of residence and seasonal variation. RESULTS: Prevalence of HEV was 13.9%. Infection with it occurred through out the year with no preponderance of cases following the monsoons. Young male adults between 20-40 years of age were predominantly affected. Prevalence of HAV was 5.5% affecting mainly children below 14 years of age. Population of urban areas around "Gandha Naliash" (a large open sewer) was at high risk as there was clustering of HEV & HAV cases around that area.

Adolescent↗
PubMedDate not supplied

Blue rubber bleb nevus syndrome: a cause of gastrointestinal hemorrhage.

Blue rubber bleb nevus syndrome is an uncommon disorder manifested by cutaneous and gastrointestinal hemangiomas and gastrointestinal hemorrhage causing anemia. We describe a young man who presented with hematemesis and melena and had multiple bluish rubber bleb-like hemangiomas over the body and in the stomach, jejunum and colon. The patient was treated with iron supplements for anemia; he is doing well 6 months later.

Adolescent↗