146 research outputs found

    Identification and functional analysis of glutamine transporter inStreptococcus mutans

    Get PDF
    Background Streptococcus mutans, a biofilm-forming bacterium, possesses several transporters that function as import/export molecules. Among them, the PII protein family is composed of members that regulate glutamine synthesis in bacterial species. Objective In this study, we characterized the function of the glutamine transporter in S. mutans MT8148. Methods The SMU.732 gene, corresponding to glnP in S. mutans, is homologous to the glutamine transporter gene in Bacillus subtilis. We constructed a glnP-inactivated mutant strain (GEMR) and a complement strain (comp-GEMR) and evaluated their biological functions. Results Growth of GEMR was similar in the presence and absence of glutamine, whereas the growth rates of MT8148 and comp-GEMR were significantly lower in the presence of glutamine as compared to its absence. Furthermore, biofilms formed by MT8148 and comp-GEMR were significantly thicker than that formed by GEMR, while the GEMR strain showed a significantly lower survival rate in an acidic environment than the other strains. Addition of n-phenyl-2-naphthylamine, used to label of the membrane, led to increased fluorescence intensity of MT8148 and GEMR, albeit that was significantly lower in the latter. Conclusions These results suggest that glnP is associated with glutamine transport in S. mutans, especially the import of glutamine involved in biofilm formation

    Photoinduced swing of a diarylethene thin broad sword shaped crystal:a study on the detailed mechanism

    Get PDF
    We report a swinging motion of photochromic thin broad sword shaped crystals upon continuous irradiation with UV light. By contrast in thick crystals, photosalient phenomena were observed. The bending and swinging mechanisms are in fact due to molecular size changes as well as phase transitions. The first slight bending away from the light source is due to photocyclization-induced surface expansion, and the second dramatic bending toward UV incidence is due to single-crystal-to-single-crystal (SCSC) phase transition from the original phase I to phase IIUV. Upon visible light irradiation, the crystal returned to phase I. A similar SCSC phase transition with a similar volume decrease occurred by lowering the temperature (phase IIItemp). For both photoinduced and thermal SCSC phase transitions, the symmetry of the unit cell is lowered; in phase IIUV the twisting angle of disordered phenyl groups is different between two adjacent molecules, while in phase IIItemp, the population of the phenyl rotamer is different between adjacent molecules. In the case of phase IIUV, we found thickness dependent photosalient phenomena. The thin broad sword shaped crystals with a 3 mu m thickness showed no photosalient phenomena, whereas photoinduced SCSC phase transition occurred. In contrast, large crystals of several tens of mu m thickness showed photosalient phenomena on the irradiated surface where SCSC phase transition occurred. The results indicated that the accumulated strain, between isomerized and non-isomerized layers, gave rise to the photosalient phenomenon

    Stent-Related Adverse Events as Related to Dual Antiplatelet Therapy in First- vs Second-Generation Drug-Eluting Stents

    Get PDF
    [Background] There are limited data on the long-term stent-related adverse events as related to the duration of dual antiplatelet therapy (DAPT) in second-generation (G2) drug-eluting stents (DES) compared with first-generation (G1) DES. [Objectives] This study sought to compare the long-term stent-related outcomes of G2-DES with those of G1-DES. [Methods] The study group consisted of 15, 009 patients who underwent their first coronary revascularization with DES from the CREDO-Kyoto PCI/CABG (Coronary Revascularization Demonstrating Outcome Study in Kyoto Percutaneous Coronary Intervention/Coronary Artery Bypass Grafting) Registry Cohort-2 (first-generation drug-eluting stent [G1-DES] period; n = 5, 382) and Cohort-3 (second-generation drug eluting stent [G2-DES] period; n = 9, 627). The primary outcome measures were definite stent thrombosis (ST) and target vessel revascularization (TVR). [Results] The cumulative 5-year incidences of definite ST and TVR were significantly lower in the G2-DES group than in the G1-DES group (0.7% vs 1.4%; P < 0.001; and 16.2% vs 22.1%; P < 0.001, respectively). The lower adjusted risk of G2-DES relative to G1-DES for definite ST and TVR remained significant (HR: 0.53; 95% CI: 0.37-0.76; P < 0.001; and HR: 0.74; 95% CI: 0.68-0.81; P < 0.001, respectively). In the landmark analysis that was based on the DAPT status at 1 year, the lower adjusted risk of on-DAPT status relative to off-DAPT was significant for definite ST beyond 1 year in the G1-DES stratum (HR: 0.42; 95% CI: 0.24-0.76; P = 0.004) but not in the G2-DES stratum (HR: 0.66; 95% CI: 0.26-1.68; P = 0.38) (Pinteraction = 0.14). [Conclusions] G2-DES compared with G1-DES were associated with a significantly lower risk for stent-related adverse events, including definite ST and TVR. DAPT beyond 1 year was associated with a significantly lower risk for very late ST of G1-DES but not for that of G2-DES

    Severe Aortic Stenosis in Dialysis Patients

    Get PDF
    Background: Characteristics and prognosis of hemodialysis patients with severe aortic stenosis have not yet been well defined. Methods and Results: The CURRENT AS (contemporary outcomes after surgery and medical treatment in patients with severe aortic stenosis) registry, a Japanese multicenter registry, enrolled 3815 consecutive patients with severe aortic stenosis. There were 405 hemodialysis patients (initial aortic valve replacement [AVR] group: N=135 [33.3%], and conservative group: N=270) and 3410 nonhemodialysis patients (initial AVR group: N=1062 [31.1%], and conservative group: N=2348). The median follow‐up duration after the index echocardiography was 1361 days, with 90% follow‐up rate at 2 years. The cumulative 5‐year incidence of all‐cause death was significantly higher in hemodialysis patients than in nonhemodialysis patients in both the entire cohort (71% versus 40%, P<0.001) and in the initial AVR group (63.2% versus 17.9%, P<0.001). Among hemodialysis patients, the initial AVR group as compared with the conservative group was associated with significantly lower cumulative 5‐year incidences of all‐cause death (60.6% versus 75.5%, P<0.001) and sudden death (10.2% versus 31.7%, P<0.001). Nevertheless, the rate of aortic valve procedure–related death, which predominantly occurred within 6 months of the AVR procedure, was markedly higher in the hemodialysis patients than in the nonhemodialysis patients (21.2% and 2.3%, P<0.001). Conclusions: Among hemodialysis patients with severe aortic stenosis, the initial AVR strategy as compared with the conservative strategy was associated with significantly lower long‐term mortality risk, particularly the risk for sudden death, although the effect size for the survival benefit of the initial AVR strategy was smaller than that in the nonhemodialysis patients

    Decline in Left Ventricular Ejection Fraction during Follow-up in Patients with Severe Aortic Stenosis

    Get PDF
    Objectives: The aim of this study was to investigate the prognostic impact of the decline in left ventricular ejection fraction (LVEF) at 1-year follow-up in patients with severe aortic stenosis (AS) managed conservatively. Background: No previous study has explored the association between LVEF decline during follow-up and clinical outcomes in patients with severe AS. Methods: Among 3, 815 patients with severe AS enrolled in the multicenter CURRENT AS (Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis) registry in Japan, 839 conservatively managed patients who underwent echocardiography at 1-year follow-up were analyzed. The primary outcome measure was a composite of AS-related deaths and hospitalization for heart failure. Results: There were 91 patients (10.8%) with >10% declines in LVEF and 748 patients (89.2%) without declines. Left ventricular dimensions and the prevalence of valve regurgitation and atrial fibrillation or flutter significantly increased in the group with declines in LVEF. The cumulative 3-year incidence of the primary outcome measure was significantly higher in the group with declines in LVEF than in the group with no decline (39.5% vs. 26.5%; p 10% declines in LVEF at 1 year after diagnosis had worse AS-related clinical outcomes than those without declines in LVEF under conservative management. (Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis Registry; UMIN000012140

    コミュニケーション ゲンゴ カツドウ ノ ジュクタツド オ アラワス JF Can-do ノ サクセイ ト ヒョウカ CEFR ノ A2 B1 レベル ニ モトヅイテ

    Get PDF
    日本語教育において言語熟達度を表す共通の枠組みがないという状況をふまえ、国際交流基金は、 CEFR に基づいた日本語の熟達度を表す能力記述文としてJF Can-do を開発中である。本稿では、JF Cando 開発の第1段階であるA2およびB1レベルのCan-do 作成と、その記述に対する現場教師の評価に ついて述べる。評価の観点は、(1)レベルが妥当か、(2)言語活動のカテゴリーが妥当か、(3)記述はわかり やすいか、(4)教室活動等がイメージしやすいか、の4点である。作成過程において現場教師による評価 を取り入れたことにより、教育現場で使いやすいCan-do を記述する際に考慮すべき点について有益な フィードバックを得た。その一方で、Can-do を十分に理解し、枠組みを共有していくためには、継続 したワークショップ等の実施が重要であることもわかった。Given that there is no common framework for Japanese language proficiency, The Japan Foundation is developing Japanese language proficiency descriptors (“JF Can-do”) based on the CEFR illustrative descriptors. This paper reports on the first stage of the development of JF Can-do (for levels A 2 and B 1) and the evaluation of the descriptions by teachers. The points of the evaluation are as follows : 1) validity of the proficiency level, 2) appropriateness of the language activity category, 3) clarity of descriptions, and 4) ease in visualizing classroom activities. Useful feedback was gained by carrying out the teachers\u27 evaluation in the process of developing JF Can-do that are easy to use in classroom situations. Meanwhile, the results also showed that continued workshops were needed in order for the teachers to fully understand and share the framework

    Initial Surgical Versus Conservative Strategies in Patients With Asymptomatic Severe Aortic Stenosis

    Get PDF
    AbstractBackgroundCurrent guidelines generally recommend watchful waiting until symptoms emerge for aortic valve replacement (AVR) in asymptomatic patients with severe aortic stenosis (AS).ObjectivesThe study sought to compare the long-term outcomes of initial AVR versus conservative strategies following the diagnosis of asymptomatic severe AS.MethodsWe used data from a large multicenter registry enrolling 3,815 consecutive patients with severe AS (peak aortic jet velocity >4.0 m/s, or mean aortic pressure gradient >40 mm Hg, or aortic valve area <1.0 cm2) between January 2003 and December 2011. Among 1,808 asymptomatic patients, the initial AVR and conservative strategies were chosen in 291 patients, and 1,517 patients, respectively. Median follow-up was 1,361 days with 90% follow-up rate at 2 years. The propensity score–matched cohort of 582 patients (n = 291 in each group) was developed as the main analysis set for the current report.ResultsBaseline characteristics of the propensity score–matched cohort were largely comparable, except for the slightly younger age and the greater AS severity in the initial AVR group. In the conservative group, AVR was performed in 41% of patients during follow-up. The cumulative 5-year incidences of all-cause death and heart failure hospitalization were significantly lower in the initial AVR group than in the conservative group (15.4% vs. 26.4%, p = 0.009; 3.8% vs. 19.9%, p < 0.001, respectively).ConclusionsThe long-term outcome of asymptomatic patients with severe AS was dismal when managed conservatively in this real-world analysis and might be substantially improved by an initial AVR strategy. (Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis Registry; UMIN000012140
    corecore