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Biomedical subjects

G Singh

Publications and source records attributed to G Singh.

At least 631 records · Page 35Linked to original sources
PubMed1987

Biochemical and immunological effects of aflatoxins in rabbits.

Aflatoxicosis caused impairment of specific and nonspecific immune responses to varying degrees in rabbits. However, the impairment was of lesser extent as compared to the earlier reports in other laboratory animals. The nonspecific response, as determined by phagocytic index was 60% of the control in test rabbits. Aflatoxicosis caused a decrease in protein content (22%), alkaline phosphatase activity (75%) and an increase (1.5-3 times) in the level of cholesterol, total lipids and acid phosphatase activity in test rabbits sera. The changes were statistically significant (P less than 0.05) in test rabbits. The test rabbits had a tendency to recover from the effects of aflatoxicosis after 3-4 weeks.

Aflatoxins↗
PubMed1987

Amino acid metabolism in Ancylostoma ceylanicum and Nippostrongylus brasiliensis.

Ancylostoma ceylanicum and Nippostrongylus brasiliensis decarboxylated most of the amino acids examined, but only a few at significant rates. The former nematode in general possessed higher activities. Striking differences between the two parasites were, however, noticed regarding the metabolism of some of the amino acids. For instance, while alanine followed by aspartate produced highest amounts of 14CO2 in the presence of A. ceylanicum, proline exhibited maximum decarboxylation in case of N. brasiliensis. Tyrosine and lysine, on the other hand, did not liberate detectable CO2 with either parasite. Likewise, although large number of amino acids underwent transamination with 2-oxoglutarate, only some of them elicited appreciable activity for any of the two parasites.

Amino Acids↗
PubMed1987

A new scheme for phage typing Salmonella bareilly and characterization of typing phages.

A new phage typing scheme using wild bacteriophages isolated from sewage for phage typing Salmonella bareilly is described. Six hundred and thirty-seven strains of Salm. bareilly could be separated into 11 different phage types using five wild phages. Overall typability was 94.5%. These phages belonged to two different morphotypes. A1 and B1, and showed varying host range.

Animals↗
PubMed1987

Glucose tolerance studies in lichen planus.

A study of glucose tolerance and insulin response to oral glucose was carried out in 56 consecutive histologically confirmed cases of lichen planus. 30.3% patients showed abnormal glucose tolerance. The pattern of insulin response was similar to that seen in type II diabetes. Insulin/glucose ratio showed the same relationship as seen in type II diabetes. These results reinforce the possibility of glucose intolerance in lichen planus patients. However, no correlation between glucose tolerance abnormalities and duration and distribution of lesions was observed.

Adult↗
PubMed1987

Augmentation of rat alveolar macrophage migration by surfactant protein.

Since the alveolar macrophage (AM) resides in an environment made unique by the presence of pulmonary surfactant, we studied the effect of constituents of pulmonary surfactant on the migration of these cells in vitro. Whole pulmonary surfactant, surfactant phospholipids, and a delipidated preparation of surfactant consisting mainly of protein were tested for their effect on AM migration. Migration was measured in multiwell chemotaxis chambers with endotoxin-activated rat serum (EARS) as the stimulus. The delipidated surfactant material (DSM) markedly augmented the migration of rat AM. Enhancement was seen only when migration was stimulated with EARS. Augmentation of stimulated migration occurred over a wide range of protein concentrations in DSM (3.5 to 56 micrograms/ml) in a dose-dependent fashion. Rat AM that were preincubated with DSM and then tested in the chemotaxis assay without DSM showed increased migration towards EARS when compared with AM preincubated in buffer alone. The enhancing effect of DSM on AM migration was significantly diminished by heating the DSM and by enzymatic digestion with trypsin, suggesting that the active constituent in DSM was protein. Thus, it appears that proteins isolated from pulmonary surfactant augment the stimulated migration of AM via an interaction between the protein and the macrophage. Although the identity of these proteins remains to be elucidated, it is unlikely they include albumin since purified rat serum albumin in concentrations comparable to that of protein in DSM did not enhance the stimulated migration of AM. These results represent further confirmation that constituents of surfactant modulate the clearance function of AM in vitro. Thus, it is likely that surfactant plays a role in lung defense mediated by AM.

Animals↗
PubMed1987

Ultrastructural localization of rat Clara cell 10 KD secretory protein by the immunogold technique using polyclonal and monoclonal antibodies.

Using a monoclonal antibody and affinity-purified polyclonal antiserum against a 10 KD protein isolated from rat pulmonary lavage, we have localized the protein within Clara cells by a post-embedment protein A-gold technique. The gold particles were localized over the secretory granules of rat Clara cells. Ultrastructural immunolocalization was abolished when the primary antibodies were previously absorbed with purified 10 KD protein. Other pulmonary cells, including type II pneumocytes and ciliated cells, were negative with this technique. These results demonstrate the presence of the 10 KD protein in the secretory granules of the Clara cell and support the concept that this protein constitutes a specific and unique secretory product of Clara cells.

Animals↗
PubMed1987

Isolation and amino acid composition of the isotypes of a rat Clara cell specific protein.

A protein of molecular weight about 10,000 (Clara cell protein C) present in lung lavage fluid and specific to Clara cells has been shown to have three isotypes. The isotypes have been individually isolated and purified by a combination of molecular sieving, ion exchange chromatography, column chromatofocusing, and reverse phase chromatography. The protein was monitored by immunoblotting and its purity tested by silver staining of the gel following sodium dodecyl sulfate-polyacrylamide gel electrophoresis. About 33.7% of the 10-kDa protein present in starting rat lavage was recovered in final pure preparation. The 10-kDa Clara cell protein amounted to 0.38% of the total protein in rat lung lavage fluid. The three isotypes were present in a ratio of 1.0:2.8:8.8, the amounts increasing with decreasing pI. None of the isotypes bound to concanavalin A. The amino acid compositions of the three isotypes were similar and were remarkable in that the contents of leucine, glutamic acid, aspartic acid, serine, and proline were high, tyrosine was present in low amounts, and methionine and histidine were absent.

Amino Acids↗
PubMed1987

Oral habits.

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Child↗
PubMed1987

Cellular immunity to collagen in periodontal disease: role of T, B lymphocytes and adherent cells.

Peripheral blood lymphocytes of patients with periodontal disease and control subjects were fractionated into T enriched and B enriched lymphocyte populations and plastic adherent cells (PACs). T enriched and B enriched lymphocytes were cultured: (a) with human Type I collagen with varying concentrations of PACs and (b) without collagen, but with cells or supernatants from autologous and heterologous PACs which had been previously cultured with and without collagen. In patients with periodontal disease, both T enriched and B enriched blastogenic responses were higher than in control subjects, but B enriched cell responses of patients were highest. The addition of PACs had no significant effect upon the enriched T cell responses to collagen; the B enriched cell responses were enhanced in the presence of PACs, the maximum response occurring with the addition of approximately 10% PACs. T enriched cells did not appear to respond to the collagen co-cultured PACs or PAC supernatants; B enriched cells responded maximally to PACs co-cultured with collagen. Autologous PACs, co-cultured with collagen, induced higher responses than heterologous PACs similarly treated.

Adult↗
PubMed1986

gamma-Glutamyl transpeptidase: a novel biochemical marker in inflammation.

gamma-Glutamyl transpeptidase (gamma-GT) plays an important role in the turnover of glutathione and protein biosynthesis. Because in inflammation both catabolic and anabolic steps are activated together with migration of cells, an alteration in gamma-GT activity was postulated to occur at the site of inflammation with the development of the inflammatory process. We discovered that gamma-GT activity was increased markedly at sites of inflammation produced in several ways in rats. A significant increase in enzyme activity appeared soon after the induction of inflammation. In carrageenin-induced acute inflammation, the paw tissue attained a 3- to 4-fold increase in enzyme activity within 4 hr; in established adjuvant arthritis, a 20- to 24-fold increase over its basal activity occurred in the rat paw tissue. The specific enzyme activity was 20-22 nmoles/min/mg protein in the cellular sediment of carrageenin-induced pleural exudate. In cotton granulomatous tissue it was 5- to 6-fold higher compared to the enzyme activity of the skeletal muscles. The in vivo increase in gamma-GT activity was prevented from occurring in proportion to the anti-inflammatory potencies of the test drugs given orally. The prevention of enzyme activity was observed with indomethacin in carrageenin-induced edematous paw tissue and with phenylbutazone in both adjuvant arthritis and carrageenin-induced pleural exudate. Prednisolone was observed to be the most potent drug against cotton granuloma. Nonsteroidal anti-inflammatory drugs (NSAIDs) were not found to affect enzyme activity in vitro when incubated with cellular infiltrate from a cotton pellet granuloma. Differences in certain physico-chemical characteristics, viz. stability at 50 degrees, pH dependency and effects of solvents, were not discernible in between the enzyme activities of the untreated and edematous paw tissues. The studies thus suggest that measurement of gamma-GT in inflammation may prove to be a valuable biochemical marker for the assessment of anti-inflammatory activity of drugs in vivo.

Animals↗