細胞膜近傍のカリウムイオン濃度変化を可視化するタンパク質複合型蛍光プローブの開発

学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 浦野 泰照, 東京大学教授 大和田 智彦, 東京大学教授 井上 将行, 東京大学教授 金井 求, 東京大学教授 富田 泰輔University of Tokyo(東京大学

The Wood Odor Caused by Hand Sawing

本研究の目的は，ヒノキ集成材で製作された木製品のにおいと，その製品に使用された板材を被験者が手びきのこぎりびきする際に生じるにおいとについて，測定機による検査と官能検査とで比較することである。被験者は大学生と中学生とした。測定機での検査では，ほとんどの被験者ののこぎりびきにおいて測定されたにおいの値が木製品のそれより大変大きかった。板材の切断に要する時間が短いほどにおいの値が大きかった。官能検査でにおいの強度と快・不快度を調べると，切断に要する時間が短いほどにおいの強度が大きくなり，においの強度が大きいと快度が大きくなった。のこぎりびき中に大学生が感じたにおいの強度は，木製品各部のそれより大きかった。ヒノキ集成材を手びきのこぎりびきして生じるにおいの強度の大きさが認識された

Inhibition of activated factor X by rivaroxaban attenuates neointima formation after wire-mediated vascular injury

Accumulating evidence suggests that activated factor X (FXa), a key coagulation factor, plays an important role in the development of vascular inflammation through activation of many cell types. Here, we investigated whether pharmacological blockade of FXa attenuates neointima formation after wire-mediated vascular injury. Transluminal femoral artery injury was induced in C57BL/6 mice by inserting a straight wire. Rivaroxaban (5 mg/kg/day), a direct FXa inhibitor, was administered from one week before surgery until killed. At four weeks after surgery, rivaroxaban significantly attenuated neointima formation in the injured arteries compared with control (P<0.01). Plasma lipid levels and blood pressure were similar between the rivaroxaban-treated group and non-treated group. Quantitative RT-PCR analyses demonstrated that rivaroxaban reduced the expression of inflammatory molecules (e.g., IL-1β and TNF-α) in injured arteries at seven days after surgery (P<0.05, respectively). In vitro experiments using mouse peritoneal macrophages demonstrated that FXa increased the expression of inflammatory molecules (e.g., IL-1β and TNF-α), which was blocked in the presence of rivaroxaban (P<0.05). Also, in vitro experiments using rat vascular smooth muscle cells (VSMC) demonstrated that FXa promoted both proliferation and migration of this cell type (P<0.05), which were blocked in the presence of rivaroxaban. Inhibition of FXa by rivaroxaban attenuates neointima formation after wire-mediated vascular injury through inhibition of inflammatory activation of macrophages and VSMC

Structural basis of Sec-independent membrane protein insertion by YidC

[プレスリリース]バイオサイエンス研究科膜分子複合機能学研究室の塚崎智也准教授らの研究グループが、タンパク質を細胞膜に組み込むメカニズムを解明しました（2014/04/17）Newly synthesized membrane proteins must be accurately inserted into the membrane, folded and assembled for proper functioning. The protein YidC inserts its substrates into the membrane, thereby facilitating membrane protein assembly in bacteria; the homologous proteins Oxa1 and Alb3 have the same function in mitochondria and chloroplasts, respectively1, 2. In the bacterial cytoplasmic membrane, YidC functions as an independent insertase and a membrane chaperone in cooperation with the translocon SecYEG3, 4, 5. Here we present the crystal structure of YidC from Bacillus halodurans, at 2.4 Å resolution. The structure reveals a novel fold, in which five conserved transmembrane helices form a positively charged hydrophilic groove that is open towards both the lipid bilayer and the cytoplasm but closed on the extracellular side. Structure-based in vivo analyses reveal that a conserved arginine residue in the groove is important for the insertion of membrane proteins by YidC. We propose an insertion mechanism for single-spanning membrane proteins, in which the hydrophilic environment generated by the groove recruits the extracellular regions of substrates into the low-dielectric environment of the membrane

Surrounding Gastric Mucosa Findings Facilitate Diagnosis of Gastric Neoplasm as Gastric Adenoma or Early Gastric Cancer

Background and Aim. It is difficult to master the skill of discriminating gastric adenoma from early gastric cancer by conventional endoscopy or magnifying endoscopy combined with narrow-band imaging, because the colors and morphologies of these neoplasms are occasionally similar. We focused on the surrounding gastric mucosa findings in order to determine how to discriminate between early gastric cancer and gastric adenoma by analyzing the characteristics of the gastric background mucosa. Methods. We retrospectively examined 146 patients who underwent endoscopic submucosal dissection for gastric neoplasm between October 2009 and January 2015. The boundary of atrophic gastritis was classified endoscopically according to the Kimura-Takemoto classification system. Of 146 lesions, 63 early gastric cancers and 21 gastric adenomas were ultimately evaluated and assessed. Results. Almost all gastric adenomas were accompanied by open-type gastritis, whereas 47 and 16 early gastric cancers were accompanied by open-type and closed-type gastritis, respectively (p = 0.037). Conclusions. The evaluation of the boundary of atrophic gastritis associated with gastric neoplasms appears to be useful for discrimination between early gastric cancer and gastric adenoma. When gastric neoplasm is present in the context of surrounding localized gastric atrophy, gastric cancer is probable but not certain

Adalimumab Dose-Escalation Therapy Is Effective in Refractory Crohn’s Disease Patients with Loss of Response to Adalimumab, Especially in Cases without Previous Infliximab Treatment

Background/Aims: Adalimumab dose escalation is one of the most important options in refractory Crohn’s disease patients with loss of response to adalimumab. The goal of this study was to evaluate the effectiveness of adalimumab dose escalation in Crohn’s disease patients with loss of response to adalimumab, since there are few reports of adalimumab dose escalation, especially in East Asia. Methods: The clinical response to adalimumab dose escalation in Crohn’s disease patients with loss of response to adalimumab was evaluated retrospectively, using the Crohn’s disease activity index score, serum C-reactive protein levels, and endoscopic analyses. Results: Of the 203 Crohn’s disease patients treated with anti-tumor necrosis factor, 14 refractory Crohn’s disease patients with loss of response to adalimumab received adalimumab dose-escalation therapy. The C-reactive protein level was significantly reduced from the start to weeks 12 and 52 of adalimumab dose escalation in the whole group, although there were no significant reductions of Crohn’s disease activity index scores. Both Crohn’s disease activity index scores and C-reactive protein levels were significantly reduced from the start to weeks 12 and 52 of adalimumab dose escalation in patients without previous infliximab treatment, although C-reactive protein levels were positive in all cases with previous infliximab exposure at weeks 12 and 52. Endoscopic mucosal healing was achieved with adalimumab dose escalation in 2 cases without previous infliximab treatment. Conclusions: Adalimumab dose-escalation therapy is effective in refractory Crohn’s disease patients with loss of response to adalimumab, especially in cases without previous infliximab treatment

Comparison of performance of the 2016 ACR-EULAR classification criteria for primary Sjögren\u27s syndrome with other sets of criteria in Japanese patients

Objectives To compare the performance of the new 2016 American College of Rheumatology (ACR)-European League Against Rheumatism (EULAR) classification criteria for primary Sjögren\u27s syndrome (SS) with 1999 revised Japanese Ministry of Health criteria for diagnosis of SS (JPN), 2002 American-European Consensus Group classification criteria for SS (AECG) and 2012 ACR classification criteria for SS (ACR) in Japanese patients.Methods The study subjects were 499 patients with primary SS (pSS) or suspected pSS who were followed up in June 2012 at 10 hospitals in Japan. All patients had been assessed for all four criteria of JPN (pathology, oral, ocular, anti-SS-A/SS-B antibodies). The clinical diagnosis by the physician in charge was set as the ‘gold standard’.Results pSS was diagnosed in 302 patients and ruled out in 197 patients by the physician in charge. The sensitivity of the ACR-EULAR criteria in the diagnosis of pSS (95.4%) was higher than those of the JPN, AECG and ACR (82.1%, 89.4% and 79.1%, respectively), while the specificity of the ACR-EULAR (72.1%) was lower than those of the three sets (90.9%, 84.3% and 84.8%, respectively). The differences of sensitivities and specificities between the ACR-EULAR and other three sets of criteria were statistically significant (p<0.001). Eight out of 302 patients with pSS and 11 cases out of 197 non-pSS cases satisfied only the ACR-EULAR criteria, compared with none of the other three sets.Conclusions The ACR-EULAR criteria had significantly higher sensitivity and lower specificity in diagnosis of pSS, compared with the currently available three sets of criteria