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Biomedical subjects

S Sharma

Publications and source records attributed to S Sharma.

At least 1,207 records · Page 67Linked to original sources
PubMed1988

Effect of various oxygen free radical scavengers in preventing tissue injury caused by Escherichia coli in pyelonephritic mice.

Reactive oxygen species have been found to be responsible for the tissue injury caused in experimental pyelonephritis in mice. The extent of lipid peroxidation (as assayed by malondialdehyde formation) was found to be increased significantly (p less than .001) in the infected group as compared to the normal mice. Superoxide dismutase and catalase (oxygen free radical scavengers) showed a significant decrease (p less than .001) in the extent of lipid peroxidation even in the presence of infection. Dimethyl sulfoxide, a hydroxyl ion scavenger, was however found to be effective only at 4 and 7 days postinfection (p less than .001). Allopurinol, an inhibitor of xanthine oxidase, did not significantly (p greater than .05) inhibit the formation of lipid peroxides, even upto 7 days postinfection. There was a significant decrease (p less than .05) in the activities of renal brush border membrane enzymes used as markers of renal tissue damage (i.e. alkaline phosphatase, leucine amino-peptidase and gamma-glutamyl transpeptidase) in the infected group as compared to the normal group. In the presence of superoxide dismutase, dimethylsulfoxide and catalase except allopurinol, the activities of all the enzymes but maltase were found to be increased significantly (p less than .05) as compared to the infected group. There was a significant increase (p less than .01) in the bacterial count in the presence of superoxide dismutase and DMSO in infected mice as compared to the infected control mice. However, no significant difference was observed in the catalase and allopurinol treated groups.

Allopurinol↗
PubMed1988

Isozyme polymorphism of beta-glucosidase in Aspergillus nidulans.

Electrophoretic analysis of the distribution of various electromorphs at different beta-glucosidase zones was carried out in natural populations of A. nidulans, the A. nidulans group, and various species belonging to the genus Aspergillus from diverse geographical areas of India. The data show the existence of three segregating zones for beta-glucosidase, designated beta-GluI, beta-GluII, and beta-GluIII. All three zones are present in wild isolates of A. nidulans, and only two, i.e., beta-GluI and beta-GluIII, in the A. nidulans group and beta-GluII and beta-GluIII in different species of Aspergillus except A. terreus, A. flavus, and A. brevipes, where only beta-GluIII is present. Overall nine electromorphs are observed at beta-GluI, three at beta-GluII, and six at beta-GluIII zones, respectively. It can be concluded that there may be three structural genes for beta-glucosidase coding the three polymorphic zones in A. nidulans.

Aspergillus↗
PubMed1988

Pharmacokinetics of centperazine: a new antifilarial agent.

Blood concentration compared with time profile of centperazine, obtained after intravenous injection of a 5 mg/kg dose in male albino rats, was analysed for various parameters. The data could be interpreted best in terms of the three compartment open model system. The drug exhibited 4.4 h of half-life, with an elimination constant of 1.65. Values for the area under curve and distribution volume were determined as 14.62 micrograms h/ml and 438 ml respectively. Only 10% of centperazine present in the central compartment was available for elimination at any one time. Mean plasma clearance value was found to be 72.87 ml/h/kg body weight.

Animals↗
PubMed1988

Characterization of receptors for a T cell derived cytosolic BCGF-60kD.

A 60 kD cytosolic protein derived from human peripheral blood T cells has been shown to mediate proliferation in BCGF responsive long term B cell cultures. In this report, we show cBCGF-60kD can be radioiodinated with no significant loss of biologic activity and bound specifically to B cell surface membrane receptors. The time course of 125I-cBCGF-60kD demonstrated that binding reached saturation within 40 minutes, (T 1/2 of 15 minutes). Scatchard analyses of ligand-receptor binding identified a high affinity receptor (0.6(-3) x 10(3) receptors per cell) having a dissociation constant of 1-8 pM. Partial cross-competition experiments with a secreted, T cell derived BCGF-12kD identified a potential receptor heterogeneity on BCGF responsive B cell line.

B-Lymphocytes↗
PubMed1987

Identification and analysis of left atrial isomerism.

The veno-atrial connections, atrial morphology, atrioventricular (AV) junction, ventricular mass, ventriculoarterial (VA) connection and great arteries in 22 autopsied hearts, diagnosed as having bilateral left-sidedness because of the morphology of the atrial appendages, were studied. The findings were correlated with the arrangement of the thoracic-abdominal organs. A solitary spleen was found in 3 and double spleens in 2 hearts (the remaining 17 hearts had multiple spleens) but left bronchial isomerism existed in all hearts in which bronchial arrangement could be determined. The heart was in the left chest in 14 cases, in the right chest in 5 and midline in 3. The apex pointed to the left in 18 hearts while in 4 hearts it pointed to the right. Fifteen hearts had a biventricular and ambiguous AV connection, 3 hearts had an absent left AV connection and 4 had double-inlet connection via a common valve (to the left ventricle in 3 and the right ventricle in 1). The VA connection was concordant in 14 hearts, discordant in 1, double outlet from the right ventricle in 4, double outlet from a solitary indeterminate ventricle in 1 and single outlet from the right ventricle through a pulmonary trunk with aortic atresia in 2 hearts. Superior caval veins were present bilaterally in 13 hearts. There was interruption of the infrahepatic inferior caval vein with azygos or hemiazygos continuation in 19 hearts while in 3 hearts the inferior caval vein continued upwards to drain into the right-sided morphologically left atrium.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta↗
PubMed1987

Morphological response of injured adult rabbit optic nerve to implants containing media conditioned by growing optic nerves.

Adult rabbit retina can express regeneration-associated characteristics after optic nerve injury, provided it is supplied with appropriate diffusible substances originating from media conditioned by regenerating fish optic nerves or by optic nerves of a newborn rabbit [Hadani et al., Proc. Natl. Acad. Sci. U.S.A., 81 (1984) 7965; Schwartz et al., Science, 228 (1985) 600]. This was shown by applying the active substances to the injured axons in the form of 'wrap-around' implants, consisting of collagen-coated silicone tubes which had been soaked in the conditioned media (CM). The regeneration-associated response was manifested biochemically and by sprouting of nerve fibers in culture. The present work provides morphological evidence that the implantation prolongs survival of ganglion cells and optic nerve fibers and induces new growth. Light microscopic analysis (using horseradish peroxidase (HRP) for labeling the fibers) revealed, 1 week following optic nerve injury, labeled fibers and ganglion cells in both the implanted and control (injured only or injured and implanted with collagen-coated silicone tubes free of CM) nerves. However, from the second week after the injury, distinct differences in the appearance of viable ganglion cells and labeled fibers, were seen between experimental and control preparations. In sections taken through the optic nerve, at the region distal to the site of injury, HRP-labeled fibers were seen in the experimental nerves 1 week, 2 weeks and to a significantly lesser extent 1 month after injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

New sensitive markers for the detection of experimental ascending pyelonephritis.

Kinetic parameters (Km and Vmax) of renal brush border membrane (BBM) enzymes alkaline phosphatase, maltase, leucine-aminopeptidase and gamma-glutamyltranspeptidase were used as markers for the early detection of pyelonephritis. Km of all the enzymes studied remained unaltered. The Vmax of all the enzymes studied were found to be significantly decreased (p less than 0.05) 3 or 4 days postinfection and onwards in the left obstructed kidney. The Vmax of alkaline phosphatase and leucine-aminopeptidase was found to be significantly increased (p less than 0.05) in early stages and decreased (p less than 0.05) in later stages of infection in the right unobstructed kidney. No histopathological lesions confirming pyelonephritis could be seen 7 days postinfection in the left kidney and right kidney remained histopathologically unaltered. This demonstrated that BBM enzymes are much earlier disturbed as compared to histopathological changes.

Alkaline Phosphatase↗
PubMed1987

Molecular cloning and expression of a human B-cell growth factor gene in Escherichia coli.

A human B-cell growth factor (BCGF) (12 kilodaltons) supports the clonal proliferation of B lymphocytes. A clone was isolated that contained the proper structural sequence to encode biologically active, 12-kilodalton BCGF in Escherichia coli and to hybridize to a specific messenger RNA, identified by in vitro translation in Xenopus laevis oocytes. A relatively hydrophobic region of 18 amino acids was found at the amino terminal of the 124-amino acid-long polypeptide. The carboxyl terminal is composed of at least 32 amino acids that are derived from nucleotide sequences bearing significant homology to the Alu repeat family.

Amino Acid Sequence↗