Usefulness of vonoprazan,a potassium ion-competitive acid blocker,for primary eradication of Helicobacter pylori

AIM To investigate usefulness of triple therapy with vonoprazan,a potassium ion-competitive acid blocker and antibiotics,for Helicobacter pylori(H.pylori) eradication.METHODS The H.pylori eradication rate was examined in 2507 patients(2055 undergoing primary eradication and 452 undergoing secondary eradication,excluding patients with subtotal gastrectomy) at the Japanese Red Cross Kyoto Daiichi Hospital from March 2013 to September 2015.For patients treated from March 2013 to February 2015,a proton pump inhibitor(PPI) was used to reduce acid secretion,while vonoprazan was used after March 2015.The success rates of the 2 regimens(PPI + amoxicillin + clarithromycin/metronidazole,or vonoprazan + amoxicillin + clarithromycin/metronidazole) were compared.RESULTS The success rate of primary H.pylori eradication was significantly higher in the vonoprazan group.When stratified by the underlying disease,a significant increase of the H.pylori eradication rate was observed in patients with chronic gastritis.A significantly lower H.pylori eradication rate was observed in younger patients compared to older patients in the PPI group,but there was no difference according to age in the vonoprazan group.On the otherhand,the success rate of secondary eradication was similar at approximately 90% in both groups.CONCLUSION Vonoprazan is very useful for primary eradication of H.pylori,and may become a first-line acid secretion inhibitor instead of PPIs.

Real-world efficacy of daclatasvir and asunaprevir with respect to resistance-associated substitutions

AIM To investigate daclatasvir(DCV) and asunaprevir(ASV) efficacy in hepatitis C(HCV) patients, with respect to resistance-associated substitutions(RASs).METHODS A total of 392 HCV-infected patients from multiple centers were included in this study. We evaluated their clinical courses and sustained virologic responses(SVR) according to pretreatment factors(gender, age, history of interferon-based regimens, platelet counts, level of viremia, pretreatment NA5A:L31, and Y93 substitutions). We also analyzed the pretreatment and post-treatment major RASs of NS3:D168, NS5A:L31 and Y93 substitutions using a direct-sequencing method in 17 patients who were unable to achieve SVR at 12 wk after treatment completion(SVR12).RESULTS The overall SVR12 rate was 88.3%. Thirty-one patients discontinued treatment before 24 wk because of adverse events, 23 of whom achieved SVR12. There were no significant differences in SVR12 rates with respect to gender, age, history of interferon-based regimens, and platelet counts. The SVR12 rate in patients with viral loads of ≥ 6.0 log IU/m L was significantly lower than those with viral loads of < 6.0 log IU/m L(P < 0.001). The SVR12 rate in patients with Y93 substitution-positive was significantly lower than those with Y93 substitution-negative(P < 0.001). The L31 substitution-positive group showed a lower SVR12 rate than the L31 substitution-negative group, but the difference was not statistically significant. Seventeen patients who did not achieve SVR12 and had available pretreatment and post-treatment sera had additional RASs in NS3:D168, NS5:L31, and Y93 substitution at treatment failure.CONCLUSION Combination of DCV and ASV is associated with a high SVR rate. Baseline RASs should be thoroughly assessed to avoid additional RASs after treatment failure.

A comparative study on crash-influencing factors by facility types on urban expressway

This study aims at identifying crash-influencing factors by facility type of Nagoya Urban Expressway, considering the interaction of geometry, traffic flow, and ambient conditions. Crash rate （CR） model is firstly developed separately at four facility types： basic, merge, and diverge segments and sharp curve. Traffic flows are thereby categorized, and based on the traffic categories, the significances of factors affecting crashes are analyzed by principal component analysis. The results reveal that, the CR at merge segment is significantly higher than those at basic and diverge segments in uncongested flow, while the value is not significantly different at the three facility types in congested flow. In both un- and congested flows, sharp curve has the worst safety performance in view of its highest CR. Regarding influencing factors, geometric design and traffic flow are most significant in un- and congested flows, respectively. As mainline flow increases, the effect of merging ratio affecting crash is on the rise at basic and merge segments as opposed to the decreasing significance of diverging ratio at diverge segment. Mean- while, longer acceleration and deceleration lanes are adverse to safety in uncongested flow, while shorter acceleration and deceleration lanes are adverse in congested flow. Due to its special geometric design, crashes at sharp curve are highly associated with the large centrifugal force and heavy restricted visibility.

Efficient Frontier via Production Functions and Mechanization

This study attempts to reconcile data envelopment analysis (DEA) with the production function approach in economics. We examine not only the inputs of capital and labor, but also the ranges of these inputs in production process steps, and endogenously derive a Leontief production function. The Leontief production functions shift northeasterly owing to mechanization, which is the replacement of labor inputs by capital inputs in some steps. Consequently, we describe the efficient frontier as the convex hull of the Leontief production functions. Furthermore, we consider the possibility of efficient production below the efficient frontier.