C1272F: a novel type 2A von Willebrand's disease mutation in A1 domain; its clinical significance.

Most mutations identified in 2A VWD patients are localized in the A2 domain, although missense substitutions have also been recognized in the A1 domain. We describe a novel heterozygous missense mutation in the A1 domain of VWF gene responsible for type 2A phenotype. Analysis of the complete exon 28 was carried out in a patient and his mother with life-long histories of moderate to severe bleeding and laboratory data of type 2A VWD. The analysis of exon 28 of VWF gene showed a 3815 G → T transversion resulting in C1272F mutation. It is probably associated with a group I mechanism according to patients' clinical symptoms, and, in the case of the propositus, the lack of clinical response to treatment with desmopressin. The mutation was not found in 100 normal alleles. This substitution affected the normal S-S bound between C1272 and C1458, which is involved in A1 loop structure, altering the normal multimerization and function of VWF. The VWFpp/VWF:Ag ratio in the propositus and his mother was >3, suggesting a shortened survival of VWF. We believe it is important to report the complete clinical phenotype corresponding to the new mutation to increase the knowledge in the clinical field.

Eficacia y seguridad de ranitidina 150mg vs 300 mg dos veces por día en úlcera duodenal / Effectiveness and safety of ranitidine 150 mg vs 300 mg twice a day in duodenal ulcer

Trescientos noventa y cuatro pacientes con úlcera duodenal diagnosticada endoscópica fueron randomizados para recibir ranitidina 150 mg bid o ranitidina 300 mg bid en un estudio multicéntrico, prospectivo, doble-ciego, llevado a cabo en 7 países latinoamericanos. La endoscopía a las 4 semanas mostró curación completa de las úlceras en 171 de 196 pacientes (87.2%) tratados con ranitidina 150 mg bid y 178 de 198 (89.9%) tratados con ranitidina 300 mg bid. Ambos regímenes de tratamientos fueron igualmente efectivos, reduciendo rápidamente la incidencia de los síntomas ulcerosos. Es probable que el regimen de dosis elevadas con ranitidina sea adecuado en pacientes con enfermedad ulcerosa severa (AU)

Eficacia y seguridad de ranitidina 150mg vs 300 mg dos veces por día en úlcera duodenal / Effectiveness and safety of ranitidine 150 mg vs 300 mg twice a day in duodenal ulcer

Trescientos noventa y cuatro pacientes con úlcera duodenal diagnosticada endoscópica fueron randomizados para recibir ranitidina 150 mg bid o ranitidina 300 mg bid en un estudio multicéntrico, prospectivo, doble-ciego, llevado a cabo en 7 países latinoamericanos. La endoscopía a las 4 semanas mostró curación completa de las úlceras en 171 de 196 pacientes (87.2%) tratados con ranitidina 150 mg bid y 178 de 198 (89.9%) tratados con ranitidina 300 mg bid. Ambos regímenes de tratamientos fueron igualmente efectivos, reduciendo rápidamente la incidencia de los síntomas ulcerosos. Es probable que el regimen de dosis elevadas con ranitidina sea adecuado en pacientes con enfermedad ulcerosa severa

[Effectiveness and safety of 150 mg vs 300 mg ranitidine twice a day in duodenal ulcer]. / Eficacia y seguridad de Ranitidina 150 mg vs 300 mg dos veces por día en ulcera duodenal.

394 patients with endoscopically diagnosed duodenal ulcer were randomly allocated to treatment with ranitidine 150 bid o ranitidine 300 mg bid in a prospective double-blind multicenter trial conducted in seven LatinoAmerican countries. Endoscopy at 4 weeks showed complete ulcer healing en 171 of 196 patients (87.2%) treated with ranitidine 150 mg bid and 178 of 198 (89.9%) treated with ranitidine 300 mg bid. Both treatment regimens were equally effective at rapidly reducing the incidence of ulcer-related symptoms. It is possible that higher dosage regimen of ranitidine would be useful in patients with more severe duodenal ulcer disease.

Eficacia y seguridad de Ranitidina 150 mg vs 300 mg dos veces por día en ulcera duodenal. / [Effectiveness and safety of 150 mg vs 300 mg ranitidine twice a day in duodenal ulcer]

394 patients with endoscopically diagnosed duodenal ulcer were randomly allocated to treatment with ranitidine 150 bid o ranitidine 300 mg bid in a prospective double-blind multicenter trial conducted in seven LatinoAmerican countries. Endoscopy at 4 weeks showed complete ulcer healing en 171 of 196 patients (87.2

) treated with ranitidine 150 mg bid and 178 of 198 (89.9

) treated with ranitidine 300 mg bid. Both treatment regimens were equally effective at rapidly reducing the incidence of ulcer-related symptoms. It is possible that higher dosage regimen of ranitidine would be useful in patients with more severe duodenal ulcer disease.

[Usefulness of blood cultures from central venous catheters in the diagnosis of infection of the catheter tip]. / Valor de los hemocultivos transcatéter venoso central en el diagnóstico de infección de la punta del catéter.

Central venous blood cultures, obtained through catheters have been used for diagnosis of tip infections. We prospectively studied in a consecutive way two blood culture techniques. In a group of 23 cases, the first 5 ml of catheter solution was discarded, and in the second group of 41 cases the first 10 ml of catheter solution and blood were used. Colony counts for true positive samples were 100 cfu/ml (median value) with a 95% confidence interval = 5-1000 cfu/ml. Test validation showed for all cases, first and second groups respectively: sensitivity 60%, 50% and 62.5%; specificity 91.1%, 100% and 94.7%; positive predictive values 94.1%, 100% and 93.8%; negative predictive values 73.3%, 85% and 64%. This study had a limited utility in the diagnosis of central venous catheter tip infections. Our results show that the most sensitive technique is culture of initial samples obtained through the venous access, and that a cut-off lower than those used in previous studies should be used.