Identification of wax esters inTetrahymena pyriformis

Wax esters, isolated fromTetrahymena pyriformis, have been found to contain 45% branched chain alcohols and 76% branched chain fatty acids. No esters of tetrahymanol or of sterols were found.     

The value of the Parenting Scale for measuring the discipline practices of parents of middle school children

The psychometric properties of the Parenting Scale (Arnold, O'Leary, Wolff, and Acker, 1993), a 30-item instrument originally developed to assess the discipline practices of parents of preschool children, were examined for parents of middle school students. Subjects were 298 parents of middle school student identified as at-risk for problem behavior. An exploratory factor analysis identified two factors labeled 'Overreactivity' and 'Laxness', closely resembling two of the factors found by Arnold et al., but each of these factors contained only six items. Confirmatory factor analyses, using data from the first two assessments, replicated this factor structure. The factors were significantly correlated with measures of parents' behavior, with scales from the child Behavior Checklist and Parent Daily Reports, and with the Beck Depression Inventory. The Laxness factor was less robust than the Overreactivity factor.     

Cholestatic hepatocellular injury with azathioprine: a case report and review of the mechanisms of hepatotoxicity

PURPOSE: The goal of this study is to describe asymmetrical forms of primary open angle glaucomas in black african originated patients. MATERIAL AND METHOD: Data of 514 glaucomatous patients (1022 eyes) followed between 1993 and 1997, and attending our hospital eye department are retrospectively analysed. All the participants were diagnosed as primary open angle glaucomas; asymetry was defined as a difference of 0.2 at least between the vertical cup disc ratio of the same patient. RESULTS: The mean age of all 514 glaucoma patients was 34.52 +/- 15.55 years; 254 patients (49.40%) had no differences between cup disc values while 260 remaining others had asymmetric glaucomas (50.58%). Of them, 189 (72.69%) had a difference of 0.2 between both eyes; 49 (18.8%) had 0.3 difference; 7 (2.69%) had 0.4 difference; 4 (1.53%) had 0.5 difference, and 11 (4.23%) a difference of 0.6. Besides, 114 eyes (11.15%) had a vertical ratio of 0.9 at the first diagnosis. CONCLUSION: Carefully recognition of asymmetric cup disc ratios is of great diagnostic value in the the early stages of primary open angle glaucoma because 50% of all patients presented with this clinical form in our experience. This strategy would improve early diagnosis of glaucoma in our areas.     

Effect of quercetin on Hoechst 33342 transport by purified and reconstituted P-glycoprotein

Multidrug resistance due to P-glycoprotein is a serious impediment to successful chemotherapy of cancer. Numerous compounds are known that inhibit the drug-exporting function of P-glycoprotein. Understanding the mechanisms of action of these chemosensitizers is made difficult by the complexity of the in vivo cell systems usually employed. To examine the direct effects of chemosensitizers, we have developed a system in which purified and reconstituted P-glycoprotein transports. Hoechst 33342 from the lipid membrane to the aqueous interior of proteoliposomes, requiring ATP hydrolysis (Shapiro AB and Ling V, J Biol Chem 270: 16167-16175, 1995). Here, we use this system to understand the effect on P-glycoprotein of quercetin, one of three flavonoids that have been reported to have the unique property of stimulating drug transport by P-glycoprotein in vivo (Phang et al., Cancer Res 53: 5977-5981, 1993). Since flavonoids are abundant in food, it is important to understand their effects on the function of P-glycoprotein because of the implications for cancer chemotherapy. In our hands, quercetin inhibited P-glycoprotein-mediated Hoechst 33342 efflux and enhanced accumulation, as measured by flow cytometry, by multidrug-resistant CHRC5 cells. In the purified system, quercetin strongly inhibited Hoechst 33342 transport by P-glycoprotein, at least in part by inhibiting the ATPase activity of P-glycoprotein required for transport. We conclude that the previously reported stimulatory effect of quercetin on drug efflux from multidrug-resistant cells is not a direct effect on P-glycoprotein. The ATPase domain of P-glycoprotein may be an attractive target for new chemosensitizing agents.