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OBJECTIVE: The present study evaluates the acute effect of a single-dose itraconazole administration on CYP3A phenotype, as measured by cortisol MR ratio in urine. METHODS: Twenty-four healthy Uruguayan subjects recruited according to strict inclusion criteria participated in an open-label, randomized, two-period, crossover study designed to evaluate the bioequivalence of an itraconazole formulation (Traconal 100 mg, Achê Labs, São Paulo, Brazil). The study comprised two treatment periods separated by a wash-out period of 14 days. In each period a series of venous blood samples were drawn over 48 hours. Three urine samples were obtained for CYP3A phenotyping: pre-dose, 24 and 48 hours after dosing. Blood and urine samples were assayed for itraconazole, beta-hydroxycortisol and cortisol using a validated chromatographic method. RESULTS: The ratio of the mean AUC0-inf. T/AUC0-inf. R was included in the bioequivalence range, however, due to high variability, the CI90% was not. It was found that the cortisol metabolic ratio (MR) showed inhibition relative to basal activity in a proportion of subjects 24 hours (68 +/- 6.1%, mean +/- CI95%) and 48 hours (80 +/- 7.3%, mean +/- CI95%) after ingestion of itraconazole. A significant correlation was found between itraconazole AUC0-inf. and normalized basal CYP3A MR for the reference (r = 0.62, t = 3.72, p = 0.001) and the test product (r = 0.74, t = 5.22, p = 0.00003). A good correlation existed between basal cortisol MR and the elimination half-life of itraconazole. CONCLUSIONS: The findings are in line with the hypothesis that the determination of the bioavailability of highly variable CYP3A substrates might be improved by simultaneous non-interfering phenotyping. If this is confirmed, a new methodological paradigm may need to be developed in order to take account of metabolic variability in bioequivalence evaluation of this group of drugs.

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A newly developed enzyme-linked immunosorbent assay (ELISA) IgG serological assay for the diagnosis of Helicobacter pylori infection was used recently in two epidemiological surveys in Chile. To evaluate the diagnostic efficacy of this assay in a local symptomatic pediatric population, we studied 70 school-age patients referred for upper gastrointestinal endoscopy because of complaints suggestive of gastroduodenal disease. Evidence for antral H. pylori infection was sought by three biopsy-related methods: culture, histology, and urease activity. IgG anti-H. pylori serum antibodies were determined by ELISA. Altogether, chronic antral gastritis was found in 55 patients and duodenal ulcers in nine; 11 subjects had normal histology. Sixty (86%) patients had H. pylori in the antrum. This group had significantly higher mean IgG optical density values when compared with the H. pylori-negative group (1.860 versus 0.669; p < 0.001). The sensitivity and specificity of the assay in detecting antral H. pylori were both 90%; the positive predictive value was 98% and the negative, 60%. Accuracy of the assay was superior in predicting the presence or absence of gastroduodenal lesions with a sensitivity of 96%, a specificity of 92%, a positive predictive value of 98%, and a negative predictive value of 86%. We conclude that the diagnostic efficiency of this assay renders it appropriate both to screen for H. pylori-associated gastroduodenal disease in individual patients and to be used in seroepidemiological surveys.

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A prospective study on the causal microorganism of vulvovaginitis was done to 100 ambulatory patients seen at a pediatric gynecology unit of a metropolitan hospital at Santiago, Chile, from november 1988 throughout july 1989. Samples of vaginal discharge were taken from each patient and studied for bacteria, fungi and trichomonas. Search of pinworms was also done in 55 patients by the transparent adhesive tape test. It was possible to confirm the etiology of vulvovaginitis in 81 cases. Bacteria were isolated in 68 of them, fungi in 4, Trichomonas vaginalis in one patient and pinworms in 8.

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Con el proposito de conocer el perfil de sensibilidad que actualmente tienen las cepas de H.influenzae aisladas en ninos en nuestro ambiente y orientar la terapeutica se determino la CIM en mcg/ml de los seguientes antimicrobianos: ampicilina, cloramfenicol, cefotaxime, ceftriaxone frente a 26 cepas de H. influenzae (11 de L.C.R), 7 secrecion oido medio, 5 secrecion ocular, 2 liquido pleural, 1 secrecion traqueal). Se detectaron 7 cepas (26.9%) resistentes a ampicilina(CIM >/= 2.5 mcg/ml) en 6 de las cuales se comprobo la produccion de B lactamasa; 4 cepas (15.38%) resistentes a cloramfenicol (CIM >/= 6.25 mcg/ml) de estas, 3 cepas (11.53%) presentaban resistencia a ambos antibioticos.Todas las cepas resultaron sensibles a cefotaxime y ceftriaxone

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Se estudiaron 52 cepas de hemophilus (24 H. influenzae, 4 H. parainfluenzae y 24 Haemophilus sp). aislados de diferentes procesos infecciosos en ninos del hospital L. Calvo Mackenna entre Agosto de 1980 y Agosto de 1982. Se estudio la produccion de beta - lactamasa mediante la tecnica iodometrica de Odugbemi y en algunas cepas utilizando la cefalosporina cromogena: nitrocefina). Se comparo con la sensibilidad a ampicilina mediante tecnica de difusion en agar con discos. De las cepas aisladas resultaron productoras de beta - lactamasa en 1980: 2/5 (40%); durante 1981: 12/27 (44%) y en 1982 4/20 (20%). Hubo estricta correlacion con el estudio de sensibilidad a ampicilina por difusion en agar

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Se estudiaran 41 lactantes con el diagnostico de otitis media aguda. Streptococcus pneumoniae fue el agente mas frecuente aislado (48,8%). Haemophilus influenzae se aislo como segunda etilogia. La parecentesis esta indicada en casos muy especificos y el pediatra general puede prescindir de ella en la mayoria de ellos. Conociendo las posibilidades etiologicas del cuadro se puede elegir una terapia adecuada

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