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Biomedical subjects

R Khorasani

Publications and source records attributed to R Khorasani.

24 records · Page 2Linked to original sources

Common carotid artery bifurcation: evaluation with spiral CT. Work in progress.

To determine the utility of spiral computed tomography (CT) in evaluation of carotid artery stenosis, spiral CT images of 20 patients were compared with images obtained with conventional angiography (20 patients), ultrasound (US) (15 patients), and magnetic resonance (MR) angiography (six patients). The category of stenosis was determined for each internal carotid artery on the basis of the percentage of narrowing: mild = less than 30%, moderate = 30%-69%, and severe = 70%-99%. Occlusions were also noted. The degree of carotid stenosis determined with spiral CT correlated with that determined with conventional angiography in 92% of cases, with that determined with US in 97% of cases, and with that determined with MR angiography in 100% of cases. Calcifications and large ulcers were also well delineated. Spiral CT provided an accurate anatomic depiction of the carotid bifurcation, which could be helpful in preoperative evaluation. The major disadvantage of the technique was the need to postprocess data to remove veins, calcifications, and bone structures from the images.

Adult↗

Effect of reserpine on the histochemical and biochemical properties of rat intestinal mucin.

Biochemical and histochemical parameters of intestinal mucins were examined in control and reserpine-treated rats. An assay for intestinal mucin sulfotransferase was developed and the activity shown to increase 3.4 times over control levels in rats given intraperitonal reserpine (0.5 mg/kg body wt) daily for 7 days. Histochemical staining of intestinal sections revealed an increase in sulfomucins in goblet cells of reserpine-treated rats. The effects were prominent as early as 1 day following injection, particularly in the distal third of the small intestine, and during the next 6 days these changes spread progressively to the middle and proximal thirds. After 3 days of treatment mucins were purified from each intestinal segment and compared to control mucins with respect to composition and [35S]NaSO4 incorporation. Although individual amino acid and carbohydrate molar ratios were unchanged, the total carbohydrate and sulfate content of mucins in treated animals was elevated (two to three times above control) in the middle and distal thirds of the intestine. In vivo [35S]SO4 incorporation into these mucins was also proportionaltely elevated, and was targetted to O-linked oligosaccharide side chains. These findings are consistent with an action of reserpine causing an increased production of mucin which is enriched in glycoprotein components bearing sulfated oligosaccharide chains. The relevance of these findings to the production of hypersulfated and hyperglycosylated mucins in cystic fibrosis is discussed.

Animals↗

Automated evidence-based critiquing of orders for abdominal radiographs: impact on utilization and appropriateness.

OBJECTIVE: Inappropriate utilization of diagnostic testing has been well documented. The purpose of this study was to measure the impact of presenting real time, evidence-based critiques about the appropriateness of abdominal radiograph (KUB) orders on physician decision making. DESIGN: Prospective trial where evidence-based critiques were presented to ordering clinicians in two kinds of situations: (1) a KUB was likely to have a low probability of providing useful information, or (2) an alternative view(s) was more appropriate given the clinical circumstance. There were two phases of the trial: Phase 1 was a 9-week period where evidence-based critiques were presented at the time of ordering a KUB, followed by Phase 2, a 19-week period in which orderers were randomized to receive critiques either amended to include both institutional data regarding the utility of the critiques and stronger messages about the lack of utility of the study, or the same critiques as presented in Phase 1, depending upon indication. Based upon the radiologist's report of their interpretation of the exams, the results of the examinations were scored as positive, equivocal, or negative using structured criteria. RESULTS: 299 KUBs in Phase 1 and 385 KUBs in Phase 2 received at least one critique. Cancellation rates of low yield films were low, and were similar in Phase 1 and 2, 8/258 (3%) vs. 10/283 (4%). Compliance with the recommendation for alternative view(s) was higher: 19/104 (38%) in Phase 1 vs. 96/176 (55%) in Phase 2 (p = 0.006). The results differentiated low-yield from non-low-yield films: 5% of low-yield films vs. 20% of non-low-yield films were positive in Phase 2 (p < 0.0001). Surgical physicians were less likely to cancel (p = 0.07) or to change to the suggested view(s) (p < 0.0001) than medical physicians or nurses. CONCLUSIONS: The intervention identified clinical situations in which KUBs appeared to have a low clinical yield. In response to evidence-based critiques, providers were reluctant to cancel their order, but were more willing to change to different views. To reduce the number of inappropriate radiographic films, stronger incentives or interventions may be required.

Computer Systems↗