Esomeprazole 40 mg twice daily in triple therapy and the efficacy of Helicobacter pylori eradication related to CYP2C19 metabolism.

AIM: To determine whether an increased dosage of esomeprazole 40 mg twice daily in triple therapy improved the Helicobacter pylori eradication rate for patients with different genotypes of S-mephenytoin 4'-hydroxylase (CYP2C19). METHODS: Two hundred H. pylori-infected dyspeptic patients were randomized to receive clarithromycin 500 mg twice daily and amoxicillin 1 g twice daily plus either omeprazole 20 mg or esomeprazole 40 mg twice daily for 1 week. Six weeks later, the success of H. pylori eradication was defined. The genotyping of CYP2C19 in each patient was defined as homologous, heterologous extensive metabolizer or poor metabolizer. RESULTS: The age, gender, drug compliance and proportion of CYP2C19 genotypes were similar between the two groups. The H. pylori eradication rates were also similar between the omeprazole group and the esomeprazole group (intention-to-treat analysis: 79% vs. 86%, P > 0.05; per-protocol analysis: 85% vs. 94%, P > 0.05). For patients classified as homologous extensive metabolizers, the per-protocol H. pylori eradication rate was significantly higher in the esomeprazole group than in the omeprazole group (93% vs. 76%, P < 0.05). CONCLUSION: Esomeprazole 40 mg twice daily for triple therapy may improve the H. pylori eradication compared to omeprazole-based therapy, but only for homologous extensive metabolizers of CYP2C19.

Doppler waveform analysis of the intertwin blood flow in acardiac pregnancy: implications for pathogenesis.

OBJECTIVE: To investigate interfetal hemodynamics in acardiac twins and the implications for pathogenesis. DESIGN: A retrospective study. SUBJECTS: All acardiac twins involved in this study were identified by B-mode ultrasound at a teaching hospital in Taiwan. METHODS: Color Doppler imaging and, in one case, color power angiography were used to assess umbilical blood flow between acardiac twins and their normal co-twins. Placental anastomoses were examined by pathologists after delivery. RESULTS: In total five sets of acardiac twins and their normal co-twins were enrolled. Autonomous cardiac activity in the form of a contractile pocket was detected in two cases. Analysis of the pattern of the Doppler waveforms in each case enabled us to classify the type of hemodynamics into one of three categories: 'collision-summation', typified by a pattern of cyclic alternations of bidirectional flow; 'twin-pulse', which described the simultaneous recordings of two opposite constant flows with different pulsating rates; and the 'pump in' pattern, which indicated pulsatile flow in the reversed direction towards the acardiac mass. In two cases we detected, we believe for the first time, an artery-to-vein placental anastomosis between the acardiac twin and its co-twin. The nature of the vascular connections were confirmed on pathological follow-up. CONCLUSIONS: Our observations suggest that acardiac twins may be not only the result of but also the cause of placental vascular anastomoses, which may involve either artery-to-artery or artery-to-vein anastomoses.