[The acetylator polymorphism in a Khmer population: clinical consequences]. / Polymorphisme d'acétylation dans une population khmère: conséquences cliniques.

The great variability of slow acetylator (SA) and/or rapid acetylator (RA) frequency is mainly due to ethnic-racial origin. Using the urinary elimination ratio of three metabolites of caffeine--acetylamino formylamino methyluracil (AFMU) to AFMU + 1-methyl urate (1U) + 1-methyl xanthine (1X)--we settled the acetylation phenotype in 54 independent subjects of Khmer and 70 independent subjects of Caucasian origin. Using DNA from peripheral leucocytes, we determined by PCR, in 32 Khmer and 122 Caucasian subjects, the frequencies of wild-type alleles (NAT-2 *4) and of mutated alleles (NAT-2 *5A, *6A, *7A). The frequency of SA was respectively 28 per cent and 61 per cent in Khmer and Caucasian subjects. The antimode of the distribution of the ratio was different in the two populations: 0.07 in Khmers and 0.18 in Caucasians showing a reduced acetylation capacity in the Khmer population in spite of a higher frequency of RA. The frequencies of alleles were also different between the two populations. Between Khmers and Caucasians respectively: *4: 48.4-23.8 per cent *5A: 15.6-44.2 per cent. *6A: 29.7-32.0 per cent. *7A: 6.3-0 per cent. These differences might be taken into account to define a therapeutic strategy in the treatment of tuberculosis by isoniazide.

What learners and teachers value most in ambulatory educational encounters: a prospective, qualitative study.

PURPOSE: To determine what learners and teachers value most in ambulatory learning encounters and whether the choices of the two groups are in concordance. METHOD: In 1996, the authors surveyed learners and teachers at a walk-in clinic immediately after each of 103 consecutive learning encounters. The participants answered two open-ended questions: (1) What was the one most valuable aspect of this learning encounter? and (2) List one thing that would make it better. Using qualitative analysis methods, two raters categorized the responses; their agreement was substantial (kappa = .75). RESULTS: Half the responses fit five categories: diagnosis (15%), general management (14%), physical examination skills (9%), patient selection (6%), and time issues (6%). The participants most valued general exposure to diagnosis (29%) and general management issues (29%). Regarding their suggestions for improving the encounters, 33% cited structural issues (often "more time"), while 43% had no suggestions ("nothing" or "fine as is"). Substantial concordance existed between the rankings by category of the teachers' and learners' comments, but (1) learners were more likely to rate the educational value of the encounter excellent or very good (64% vs 47%, p < .01); (2) teachers were more likely than medical students (but not interns) to place the most educational value on the physical examination (30% vs 4%, p = .001); and (3) agreement on what was most valuable in any individual encounter was poor (kappa = .03). CONCLUSIONS: In evaluating ambulatory educational encounters, learners and teachers placed highest value on general exposure to diagnosis and disease management; while the most commonly recommended changes related to structural issues, particularly inadequate time. While learners and teachers agreed in general on the relative ranking of teaching activities, they often found different things to be educationally salient in a particular encounter.

Bleeding from the endoscopically-identified Dieulafoy lesion of the proximal small intestine and colon.

OBJECTIVES: Our goal was to assess the incidence of the endoscopically-identified small intestinal and colonic Dieulafoy-like lesions in our GI bleeding population and to characterize the clinical and endoscopic features and response to endoscopic therapy. METHODS: Patients with GI bleeding from Dieulafoy lesions were identified from our Bleeding Team and GI laser data bases from August 1984 to September 1993. Clinical and endoscopic information contained within the data bases and from each patient's medical record were retrospectively reviewed. Diagnostic criteria that had been used to endoscopically diagnose a Dieulafoy lesion were arterial bleeding or nonbleeding visible vessel stigmata, all without ulceration or erosion. RESULTS: Nine patients (three male; six female; median age, 70 yr; range, 16-94) were identified from a population of 3059 patients. Symptoms included: melena (2); hematochezia (7); and unstable hemodynamics (3). The mean hemoglobin was 8.4 +/- 2.2 g/dl. There was no significant nonsteroidal antiinflammatory drug or alcohol use. Four patients had small bowel and five patients had colonic Dieulafoy's lesions. Specific sites were: distal duodenum (3); jejunum (1); cecum (1); hepatic flexure (3); and transverse colon (1). The diagnosis was made at initial endoscopy in seven patients, after two endoscopies in one patient, and after four in another patient. Active bleeding was encountered in seven patients (three small bowel; four colon). Endoscopic therapy was successful. Two patients rebled, one from the same site (small bowel) 1 yr later. Both were successfully retreated. There were no complications or deaths. CONCLUSIONS: The endoscopic Dieulafoy lesion of the small bowel and colon is infrequently encountered. The diagnosis is most often made during active bleeding. The endoscopic diagnosis requires an aggressive approach, including repeated endoscopy. Endoscopic therapy of proximal small intestinal and colonic Dieulafoy lesions is safe, effective, and should be performed.