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Biomedical subjects

D Subrahmanyam

Publications and source records attributed to D Subrahmanyam.

At least 73 records · Page 4Linked to original sources
PubMed1982

Immunological studies with sulpholipids of mycobacteria.

Antibodies to sulpholipids of mycobacteria were produced in rabbits when injected as sulpholipid-MBSA complexes and were detected by kaolin agglutination and double diffusion techniques. Sulpholipid antibodies did not cross react with any other lipids of mycobacteria except cord-factor. The antigenicity of sulpholipids appears to be due to alpha-D-trehalose and sulphate groups. Guinea pigs immunized with sulpholipid-MBSA complexes showed partial protection against tuberculous infection with M. tuberculosis H37Rv, as revealed by mortality rate and score of lesions.

Animals↗
PubMed1982

Correlation of brain-specific S-100 protein and shock-avoidance behaviour with lactational undernourishment in rats.

A study has been undertaken to find out a possible role of brain-specific S-100 protein in the impairment of learned behaviour with lactational undernourishment of rats. The results showed a decrease in the body weight, brain weight as well as brain DNA and S-100 protein of the weanling undernourished rats while the concentration of soluble brain proteins was similar in the weanling undernourished and weanling control rats. When both the groups were subjected to shock-avoidance criterion, the learning and memory were found to be deficient in the undernourished group. It was further observed that nutritional rehabilitation at weaning could not restore the learning and memory of the undernourished animals. The decrease in the concentration of brain-specific S-100 and the deficient learning and memory could be due to a possible structural underdevelopment of brain in these animals.

Animals↗
PubMed1982

Pregnancy specific proteins: suppression of in vitro blastogenic response to mitogen by these proteins.

Immunosuppressive properties of human chorionic gonadotropin (HCG), pregnancy specific B1-glycoprotein (SP-1), human alpha foetoprotein (AFP), and human placental lactogen (HPL) in mitogen-stimulated lymphocyte transformation were studied. A pregnancy serum containing high serum levels of these specific proteins was prepared from a number of pregnancy sera. The inhibitory effect of pregnancy sera on lymphocyte response to mitogen was examined after sequential removal of each of the proteins from the pregnancy serum by affinity chromatography. Greatest decrease in the suppression was observed when human chorionic gonadotropin (HCG) alone or human chorionic gonadotropin in combination with all other three specific proteins was removed from the pregnancy serum. Pregnancy specific B1-glycoprotein (SP-1) also significantly decreased the inhibitory effect of pregnancy serum. But the other two specific proteins (AFP and HPL) had minimal effect on the decrease an immunosuppression by pregnancy serum. However, even after removal of all the four pregnancy specific proteins from the pregnancy serum, complete return to normal values for lymphocyte transformation by mitogen was not observed, which indicates the presence of some other suppressive factor(s) in the pregnancy serum.

Animals↗
PubMed1982

Effect of seminal plasma and its fractions on in vitro blastogenic response to mitogen.

Five fractions of human seminal plasma were isolated on Sephadex G-100 column. The in vitro effect of whole human seminal plasma and its fractions on the lymphocyte transformation induced by phytomitogen was studied. A significant inhibition of lymphocyte response to mitogen was observed with whole seminal plasma fractions I and III at a concentration of 100-200 micrograms/ml. However fraction II stimulates the in vitro human lymphocyte transformation induced by phytomitogen at a concentration of 200 micrograms/ml. Maximum amount of inhibition by whole seminal plasma and its fractions I and III was achieved by preexposure of lymphocytes to these antigens. Pre-exposure of lymphocytes to these antigens, followed by washing, does not result in suppression of lymphocyte response to mitogen. These observations suggest that the antigens of the whole seminal plasma or of fractions I, III, and II act by simple competition with mitogen for the receptor sites on the lymphocyte membrane. Therefore, the human seminal plasma may play an immunoregulatory role against the auto- or isosensitization towards spermatozoal antigens.

Cells, Cultured↗
PubMed1982

IgE-dependent cellular adhesion and cytotoxicity to Litomosoides carinii microfilariae--nature of effector cells.

Albino rats immunized with sonicated microfilarial antigen incorporated in Freund's complete adjuvant, produce antibodies that promote cell-mediated adhesion and killing of Litomosoides carinii microfilariae in vitro. Using highly purified cell populations, it has been shown that macrophages and neutrophils are most active in this phenomenon. Eosinophils, while adhering readily to parasites in the presence of the antibody, did not affect the viability of the parasites when observed after 24 hr incubation.

Animals↗
PubMed1981

Acute dieldrin toxicity: effect on the uptake of glucose and leucine and on brush border enzymes in monkey intestine.

Administration of a single oral dose of dieldrin (20 mg/kg body wt.) to rhesus monkeys considerably elevated the uptake of glucose and the activities of brush border sucrase, lactase, maltase and alkaline phosphatase in intestine compared to control animals. Leucine uptake and leucine amino peptidase activity was significantly depressed in pesticide-treated animals. Kinetic studies with brush border sucrase revealed that augmentation of enzyme activity in pesticide-fed animals was due to an increase in the disaccharidase content.

Alkaline Phosphatase↗
PubMed1981

Effect of DDT on adipose tissue lipolysis in rat.

The effect of acute (600 mg/kg body wt) and chronic (15 mg/kg body wt/day for 45 days) 1,1,1-trichloro-2,2-bis (p-chlorophenyl)ethane (DDT) treatments of albino rats on the lipolytic activity of the adipose tissue was studied. There was no effect on the rate of glycerol release on incubation of isolated epididymal fat pads of the treated animals when compared to that of controls. Similarly, in vitro addition of DDT (10-4M) (35.4 ppm) to the fat pads did not alter their lipolytic response. Noradrenaline (NA) stimulated lipolysis, in fat pads, was also unaffected by in vitro addition of DDT. Basal as well as NA or caffeine stimulated lipolysis in isolated fat cells also remained unchanged in the presence of DDT over a range of concentrations from 10-8 M to 10-4 M.

Adipose Tissue↗
PubMed1981

Effect of DDT on adipose tissue lipolysis in rat.

The effect of acute (600 mg/kg body wt) and chronic (15 mg/kg body wt/day for 45 days) DDT treatments of albino rats on the lipolytic activity of the adipose tissue was studied. There was no effect on the rate of glycerol release on incubation of isolated epididymal fat pads of the treated animals when compared to that of controls. Similarly, in vitro addition of DDT (10(-4) M) to the fat pads did not alter their lipolytic response. Noradrenaline stimulated lipolysis, in fat pads, was also unaffected by in vitro addition of DDT. Basal as well as noradrenaline or caffeine stimulated lipolysis in isolated fat cells also remained unchanged in the presence of DDT over a range of concentrations from 10(-8) M to 10(-4) M.

Adipose Tissue↗
PubMed1981

Effect of a single oral dose of DDT on lipid metabolism in rat.

A single oral dose of 1,1,1-trichloro-2-2-bis (p-chlorophenyl)ethane (DDT) (600 mg/kg body weight) was given to rats and the levels of various lipids in adipose tissue, liver and plasma were studied. No alteration was observed in the levels of various lipid classes in these tissues except for a decrease in the phospholipid and triglyceride fractions in liver. Lipoprotein lipase activity of post-heparin plasma (protamine-sensitive and -resistant) was significantly decreased, whereas in liver and adipose tissue, the activity of this enzyme remained unchanged.

Adipose Tissue↗
PubMed1981

Effect of glycine on phospholipids of Mycobacterium smegmatis ATCC 607.

Addition of glycine in low concentrations to modified Youman's medium led to a slight increase in both the total lipid and phospholipid content of Mycobacterium smegmatis ATCC 607 without a concomitant alteration in either the ratio of the individual phospholipids or the amount and characteristics of growth. However, high concentrations of glycine led to a decrease in both the total lipid and phospholipid content, a change in the ratio of the individual phospholipids, a decrease in the amount of growth and a change in its characteristics. The association of a decrease in the amount of growth and a change in its characteristic with a decrease in the content of triacylated mannophosphoinositides points to the biological importance of these phosphoglycolipids.

Glycine↗
PubMed1981

Intestinal brush border membrane structure and function: effect of early postnatal undernutrition.

The effect of undernutrition during suckling has been investigated on the brush border enzymes and the intestinal uptake of D-glucose and glycine in rats at weaning. The brush border sucrase and alkaline phosphatase activities were drastically reduced, but lactase and leucine aminopeptidase levels were significantly elevated in the intestine of nutritionally deprived pups compared to controls. The uptake of D-glucose and glycine in undernourished rats was also augmented. The chemical composition of the brush border membrane analyzed in nutritionally deficient animals revealed an enhancement of the membrane protein, sialic acid, cholesterol, and phospholipids compared to the control group. [U-14C]D-Glucose incorporation into lipid constituents of the membrane suggested that the observed enhancement of the membrane lipids is the result of an increased synthesis in response to undernutrition.

Animals↗