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Biomedical subjects

R N Sharma

Publications and source records attributed to R N Sharma.

At least 55 records · Page 3Linked to original sources

Thermogravimetric analysis of urinary stones.

Routine thermogravimetric (TG) analysis of 501 upper urinary calculi from the State of Jammu and Kashmir is described. The technique is simple, rapid and quantitative, and the equipment is easily maintained. The technique was found to be helpful in 95.4% of urinary stones and it is suggested that TG analysis may be employed as a technique of first choice in the routine quantitative analysis of all urinary calculi.

Calcium Oxalate↗

Cyclopcidal activity of some new insect growth regulators.

A series of synthetic terpenoid diethers, with known mosquito development inhibitory activity, were tested for cyclopcidal activity against adult cyclops, Mesocyclops leuckarti. Four among these exhibited promising activity comparable to that of the conventional organophosphate, temephos, thus providing for the first time a possible reserve arsenal for the control of the guineaworm disease vector.

Animals↗

Purification and characterization of P-52 (glutathione S-transferase-P or 7-7) from normal liver and putative preneoplastic liver nodules.

A previous study from our laboratory (L.C. Eriksson et al., Biochem. Biophys. Res. Commun., 117: 740-745, 1983) revealed that a cytosolic polypeptide of approximate Mr 21,000 (designated P-21) was markedly elevated in amount in hepatocyte nodules induced by six different regimens. The molecular weight of this polypeptide, subsequently revised to approximately 26,000, was redesignated P-26 and was identified (T.H. Rushmore et al., Biochem. Biophys. Res. Commun., 143: 98-103, 1987) as a subunit of a placental form of glutathione S-transferase (K. Sato et al., Gann 75: 199-202, 1984), also named glutathione S-transferase 7-7 (H. Jensson et al., FEBS Lett., 187: 115-120, 1985). We describe here a convenient method for purifying relatively large amounts of P-26 from hepatocyte nodules involving the sequential use of affinity chromatography on S-hexyl glutathione-Sepharose 4B, CM-Sephadex, and DEAE-Sephacel. Evidence is presented that P-26 exists as a dimer of approximate Mr 52,000 (P-52). Analyses by two-dimensional electrophoresis have indicated that the subunits of Mr 26,000 may consist of five separate charged isomers. Investigations using appropriate antisera and analysis by amino acid sequencing have provided additional confirmation that P-52 is probably identical to rat placental glutathione S-transferase. Antibodies to P-52 are proving to be useful as a marker of new cell populations that appear regularly during hepatocarcinogenesis.

Amino Acid Sequence↗

Unusual urethral duplication.

Urethral duplication is a rare congenital anomaly occurring almost exclusively in males. The described varieties include the sagital (Y-duplication), spindle, epispadiac, hypospadiac, complete, incomplete, abortive and collateral duplications. Whereas over 150 cases of this anomaly have been reported in the world literature, the associated findings of an adenocarcinoma of the urinary bladder and a urethral calculus have not been previously encountered. This case report describes the clinical presentation, the extraordinary intraoperative finding of an adenocarcinoma of the fundus of the urinary bladder, the investigative procedures, the management and follow-up of this most unusual complete urethral duplication.

Adenocarcinoma↗

Identification of a characteristic cytosolic polypeptide of rat preneoplastic hepatocyte nodules as placental glutathione S-transferase.

Evidence is presented that a distinctive type of glutathione-S-transferase (GSHTase-P), and a cytosolic polypeptide of Mr 52,000 (P-52), each appearing in greatly increased amounts in hepatocyte nodules during liver carcinogenesis in the rat, are so far indistinguishable. The probable identity of the two polypeptides was established with the use of SDS polyacrylamide gel electrophoresis and Western blot techniques with purified GSHTase-P and P-52 and their respective antibodies and by comparison of the sequence of the first 26 N-terminal amino acids. Since the enzyme and the polypeptide are each considered to be the best available early markers for hepatocyte nodules, as putative precancerous lesions, their probable identity makes them attractive cellular components for in depth studies on their transcriptional and translational regulation and their use in new approaches to the sequential analysis of liver carcinogenesis.

Amino Acid Sequence↗

Recurrent abdominal pain as the sole manifestation of hereditary angioedema in multiple family members.

This paper describes a previously unreported finding of abdominal pain as the only lifelong manifestation of hereditary angioedema in multiple family members. This diagnosis was obscured by the absence of cutaneous, oropharyngeal, and respiratory involvement. Barium studies performed during painful attacks showed transient intestinal wall edema which, along with abnormalities in the C4 level and C1 esterase inhibitor activity, confirmed the diagnosis. It is important that hereditary angioedema be recognized in its various forms so that invasive procedures can be avoided and prophylactic therapy can be administered.

Abdomen↗

Correlation between mouse skin inflammation induced by arachidonic acid and eicosanoid synthesis.

We and others have shown that arachidonic acid (AA), when applied topically to ear surfaces, causes an intense acute inflammatory reaction within minutes (as measured by ear thickness). In this study, we have investigated the cellular and biochemical changes associated with this phenomenon and have attempted to correlate these changes with the induction of inflammation. Measurement of vascular permeability by the accumulation of [125I]albumin showed that significant plasma exudation was observed at 15 min in AA-treated ears. Furthermore, the increase in [125I]albumin was time related and was nearly 10-fold greater than control at 1 h. No time-related change in plasma exudation was observed with control ears. Measurement of LTC4 by radioimmunoassay showed that there was a significant increase in LTC4 synthesis at 15 min after AA treatment. Maximal LTC4 synthesis occurred at 15 min and subsequently decreased to 30% of peak level at 30 min. Histological examination and myeloperoxidase measurement indicated that few neutrophils were present at these early time points and suggested that cells other than neutrophils are contributing to LTC4 synthesis. Ear thickness, [125I]albumin accumulation and leukotriene C4 (LTC4) synthesis in AA-treated ears were reduced significantly by topically administered mixed lipoxygenase (LO) and cyclooxygenase inhibitors such as BW755C and phenidone. Therefore, we suggest that AA-induced ear inflammation is a suitable screen for detecting LO inhibitors in vivo.

Animals↗

A characteristic electrophoretic pattern of cytosolic polypeptides from hepatocyte nodules generated during liver carcinogenesis in several models.

The cytosolic polypeptides of hepatocyte nodules in six models of liver carcinogenesis were analysed by SDS-polyacrylamide gel electrophoresis and their patterns compared with these of control and variously treated livers. The amount of a polypeptide of Mr 21,000 was about tenfold elevated in the cytosol of five of the six types of nodules and moderately elevated in the sixth. Certain other polypeptides, particularly one of Mr 26,000, also varied in amount, so that all of the nodules analysed could be distinguished from liver by their electrophoretic patterns. Some possible identities of the two polypeptides are discussed. Their study may have mechanistic as well as diagnostic importance.

Aging↗