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P V S Kumar

Publications and source records attributed to P V S Kumar.

5 recordsLinked to original sources
PubMed2005

Tinospora cordifolia induces enzymes of carcinogen/drug metabolism and antioxidant system, and inhibits lipid peroxidation in mice.

The present study is an effort to identify a potent chemopreventive agent against various diseases (including cancer) in which oxidative stress plays an important causative role. Here, we investigated the effect of a hydroalcoholic (80% ethanol: 20% distilled water) extract of aerial roots of Tinospora cordifolia (50 and 100mg/kg body wt./day for 2 weeks) on carcinogen/drug metabolizing phase-I and phase-II enzymes, antioxidant enzymes, glutathione (GSH) content, lactate dehydrogenase and lipid peroxidation in liver of 8-week-old Swiss albino mice. The modulatory effect of the extract was also examined on extrahepatic organs, i.e., lung, kidney and forestomach, for the activities of GSH S-transferase (GST), DT-diaphorase (DTD), superoxide dismutase (SOD) and catalase. Significant increases in the levels of acid-soluble sulfhydryl (-SH) and cytochrome P(450) contents, and enzyme activities of cytochrome P(450) reductase, cytochrome b(5) reductase, GST, DTD, SOD, catalase, GSH peroxidase (GPX) and GSH reductase (GR) were observed in the liver. Both treated groups showed decreased malondialdehyde (MDA) formation. In lung SOD, catalase and GST; in kidney SOD and catalase; and in forestomach SOD, DTD and GST showed significant increase at both dose levels of treatment. BHA (0.75%, w/w in diet), a pure antioxidant compound, was used as a positive control. This group showed increase in hepatic levels of GSH content, cytochrome b(5), DTD, GST, GR and catalase, whereas MDA formation was inhibited significantly. In the BHA-treated group, the lung and kidney showed increased levels of catalase, DTD and GST, whereas SOD was significantly increased in the kidney and forestomach; the latter also showed an increase in the activities of DTD and GST. The enhanced GSH level and enzyme activities involved in xenobiotic metabolism and maintaining antioxidant status of cells are suggestive of a chemopreventive efficacy of T. cordifolia against chemotoxicity, including carcinogenicity, which warrants further investigation of active principle (s) present in the extract responsible for the observed effects employing various carcinogenesis models.

Animals↗
PubMed2003

Endoluminal ultrasonography before retrograde endopyelotomy: can the results match laparoscopic pyeloplasty?

OBJECTIVE: To present the results of endopyelotomy using endoluminal ultrasonography (EUS) to identify crossing vessels, as the success rates of endopyelotomy are generally lower than pyeloplasty, especially in patients with crossing vessels. PATIENTS AND METHODS: Forty-one consecutive patients who underwent EUS before a planned retrograde endopyelotomy were analysed retrospectively. EUS was used to direct the endopyelotomy incision for patients with crossing vessels. Treatment was considered successful if the patient was asymptomatic and unobstructed or improved on renography. The results were compared to those from 18 patients treated by laparoscopic pyeloplasty, some of whom had undergone EUS. RESULTS: Crossing vessels were identified in 27 of the 41 patients (66%). Primary treatment consisted of endopyelotomy for 26 patients and laparoscopic pyeloplasty for 15. The overall success rate for 24 endopyelotomy patients with an adequate follow-up (mean 19 months) was 71%, with more success in patients with no crossing vessels (11 of 13 (85%) vs six of 11 (55%)). Of the 18 patients treated by laparoscopic pyeloplasty (mean follow-up 15.1 months) 17 were successful. CONCLUSION: The results for endopyelotomy were disappointing in patients with crossing vessels, despite using EUS. The results suggest that patients with crossing vessels should be treated by laparoscopic pyeloplasty. More data are needed to compare endopyelotomy with laparoscopic pyeloplasty in patients with no crossing vessels.

Adolescent↗
PubMed2002

A computer assisted surgical trainer for transurethral resection of the prostate.

PURPOSE: We developed a realistic and reusable computer assisted surgical training system for transurethral resection of the prostate. MATERIALS AND METHODS: A disposable prostate model is housed in a model abdomen. A software program that provides a 3-dimensional (D) illustration of the prostate model was developed. Resectoscope position with reference to the model is tracked by infrared emitting diodes attached to it, which in turn are monitored by an optical tracker. Movement of the loop in relation to the resectoscope is measured by a potentiometer attached to the working element. RESULTS: Resectoscope position was shown on the monitor superimposed on a 3-D image of the prostate model in real time. A 2-D image showed the amount of tissue resected and the proximity of the loop to the capsule. A series of thumbnail images were shown and the highlighted image represented the current position of the resectoscope. It is intended that this system should be interactive, providing continuous feedback on the progress of resection and acting as an interactive training aid. During the course of validating the system several problems were noted, mainly with model movement and permanent deformation of the model during resection. CONCLUSIONS: This system can exist as a stand-alone training aid after the problems have been addressed. The potential application of an in vivo system for routine transurethral prostate resection has great implications for training and quality control.

Computer Simulation↗