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Chandra Prakash

Publications and source records attributed to Chandra Prakash.

22 records · Page 2Linked to original sources
PubMed2003

The colon single-stripe sign and its relationship to ischemic colitis.

OBJECTIVES: Endoscopic findings may assist in the clinical diagnosis of ischemic colitis but have not been systematically characterized. We noted that a single linear colonic ulcer could on occasion be found endoscopically after hypotension and proceeded to investigate its relationship to ischemic colitis. METHODS: Twenty-six patients (19 female and seven male, mean age 71 yr) with endoscopic evidence of a single linear ulcer running along the longitudinal axis of the colon (colon single-stripe sign (CSSS) were retrospectively studied. Colitis etiologies were determined in the CSSS patients and in 58 consecutive patients without a stripe forming a colitis comparison group; clinical course and outcome in CSSS patients subsequently were compared with those in 22 patients with circumferentially involved ischemic colitis. RESULTS: The CSSS was >/=5 cm in length in all instances and isolated to a segment of the left colon in 89%. Evidence of a preceding ischemic event was noted significantly more often in the CSSS (62%) patients than in the colitis comparison group (7%) (p < 0.0001). On blinded histopathological examination, 75% of CSSS cases had microscopic evidence of ischemic injury compared with 13% in the colitis comparison group (p < 0.0001). None of the CSSS patients required surgical intervention, whereas six (27%) patients from the circumferential ischemic colitis group underwent exploration (p < 0.05). Nine patients (41%) in the circumferential ischemic colitis group died, whereas there was one death in the CSSS group (4%) (p < 0.05). CONCLUSIONS: Ischemia can manifest endoscopically as the CSSS. This sign seems to characterize milder disease in the clinical spectrum of ischemic colitis.

Aged↗
PubMed2003

Metabolism, pharmacokinetics, and excretion of a highly selective N-methyl-D-aspartate receptor antagonist, traxoprodil, in human cytochrome P450 2D6 extensive and poor metabolizers.

The excretion, biotransformation, and pharmacokinetics of a selective N-methyl-D-aspartate receptor antagonist, traxoprodil, were investigated in six healthy male volunteers, phenotyped either as CYP2D6 extensive or poor metabolizers of dextromethorphan. Each subject received an i.v. infusion of a single 50-mg (100 microCi) dose of [(14)C]traxoprodil. Approximately 89% of the administered dose was recovered in poor metabolizers (PMs) and 61% in extensive metabolizers (EMs), with the majority of the dose being excreted in the urine (86% in PMs and 52% in EMs). The elimination of traxoprodil was more rapid in EMs than in PMs with terminal elimination half-lives of 2.8 and 26.9 h, respectively, for EMs and PMs. Area under the plasma concentration-time curve from time 0 to T (AUC((0-Tlast))) values for unchanged traxoprodil were 1.2 and 32.7% of the corresponding AUC values for total radioactivity in EMs and PMs, respectively. Traxoprodil was metabolized in both EMs and PMs, with approximately 7 and 50% of the administered radioactivity excreted as unchanged drug in the excreta of EMs and PMs, respectively. Hydroxylation at the 3-position of the hydroxyphenyl ring and methylation of the resulting catechol followed by conjugation were identified as the main metabolic pathways in EMs. In contrast, direct conjugation of traxoprodil with glucuronic or sulfuric acid was the major pathway in PMs. In vitro studies using CYP2D6-selective inhibitor and recombinant enzyme also support that the metabolism of traxoprodil is mainly mediated by CYP2D6. Taken together, these studies suggest that traxoprodil is eliminated mainly by Phase I oxidative metabolism mediated by CYP2D6 isozyme in EMs and by Phase II conjugation and renal clearance of parent in PMs.

Adolescent↗
PubMed2002

Esophageal motor disorders.

Refinements continue in the measurement, display, and interpretation of pressure events that serve as signatures of esophageal motor disorders, and esophageal manometry retains its position as the diagnostic gold standard. The focus of attention remains with achalasia, not because of pathophysiologic developments or changing prevalence, but in response to the growing interest in minimally invasive surgery and its success. Some controversy remains regarding the role of preoperative motility assessments in patients undergoing antireflux surgery, as peristaltic features do not solely predict outcome. The disconnect between motor dysfunction and symptoms continues to promote careful consideration of sensory dysfunction as a component of esophageal motor disorders.

Journal Article↗