The lectin‐like domain of thrombomodulin is a drug candidate for both prophylaxis and treatment of liver ischemia and reperfusion injury in mice

Ischemia and reperfusion injury (IRI) can occur in any tissue or organ. With respect to liver transplantation, the liver grafts from donors by definition experience transient ischemia and subsequent blood reflow. IRI is a problem not only in organ transplantation but also in cases of thrombosis or circulatory disorders such as mesenteric ischemia, myocardial, or cerebral infarction. We have reported that recombinant human soluble thrombomodulin (rTM), which is currently used in Japan to treat disseminated intravascular coagulation (DIC), has a protective effect and suppresses liver IRI in mice. However, rTM may not be fully safe to use in humans because of its inherent anticoagulant activity. In the present study, we used a mouse liver IRI model to explore the possibility that the isolated lectin-like domain of rTM (rTMD1), which has no anticoagulant activity, could be effective as a therapeutic modality for IRI. Our results indicated that rTMD1 could suppress ischemia and reperfusion-induced liver damage in a dose-dependent manner without concern of associated hemorrhage. Surprisingly, rTMD1 suppressed the liver damage even after IR insult had occurred. Taken together, we conclude that rTMD1 may be a candidate drug for prevention of and therapy for human liver IRI without the possible risk of hemorrhage

Comparisons of Postoperative Complications and Nutritional Status After Proximal Laparoscopic Gastrectomy with Esophagogastrostomy and Double-Tract Reconstruction

[Background] The purpose of this study was to compare postoperative complications and nutritional status between esophagogastrostomy and double-tract reconstruction in patients who underwent laparoscopic proximal gastrectomy, and assess the advantages of both surgical procedures. [Methods] Between 2010 and 2018, 47 cases underwent proximal gastrectomy with esophagogastrostomy (n = 23) or double-tract reconstruction (n = 24) at our institution for the treatment of clinical T1N0 adenocarcinoma located in the upper third of the stomach. Patient clinical characteristics, short-term outcomes, nutrition status, and skeletal muscle index were compared among the two groups. [Results] There was no significant difference between esophagogastrostomy and double-tract reconstruction in terms of operation time, blood loss, and length of postoperative hospital stay. Reflux symptoms and anastomotic stenosis were significantly higher in the esophagogastrostomy group compared with the double-tract reconstruction group (P < 0.001 and P = 0.004, respectively). There was no significant difference in anastomotic leakage, surgical site infection, and pancreatic fistula. For the nutritional status, the decrease rate of cholinesterase was significantly higher in the esophagogastrostomy group compared with the double-tract reconstruction group at 6 months (P = 0.008) There was no significant difference in the decrease rate of skeletal muscle mass index at 1 year after surgery. [Conclusion] Compared with esophagogastrostomy, double-tract reconstruction tends to have better short-term nutritional status and postoperative outcomes in terms of preventing the occurrence of gastroesophageal reflux and anastomosis stenosis. These findings suggest that double-tract reconstruction may be a useful method in laparoscopic proximal gastrectomy

Platelet-to-Lymphocyte Ratio Multiplied by the Cytokeratin-19 Fragment Level as a Predictor of Pathological Response to Neoadjuvant Chemotherapy in Esophageal Squamous Cell Carcinoma

[Background] The standard treatment for resectable advanced esophageal squamous cell carcinoma in Japan is surgery followed by neoadjuvant chemotherapy, and it is important to predict the effect of neoadjuvant chemotherapy before treatment. Therefore, this study aims to extract conventional blood examination data, such as tumor markers and/or inflammatory/nutritional index levels, that can predict the pathological response of patients with esophageal squamous cell carcinoma to neoadjuvant chemotherapy. [Methods] We retrospectively analyzed the medical records of 66 patients with thoracic esophageal squamous cell carcinoma who received neoadjuvant chemotherapy, followed by curative esophagectomy at Tottori University Hospital between June 2009 and December 2019. [Results] We demonstrated that the product of the platelet-to-lymphocyte ratio (PLR) multiplied by the cytokeratin-19 fragment (CYFRA) level, which was termed “PLR-CYFRA,” is the most accurate indicator that predicts the pathological response to neoadjuvant chemotherapy, with the highest area under the curve [0.795 (95% confidence interval: 0.665–0.925), P < 0.001] in receiver operating characteristic analyses. Therefore, we divided patients into the PLR-CYFRALow (< 237.6, n = 21) and PLR-CYFRAHigh (≥ 237.6, n = 45) groups and found that the percentage of PLR-CYFRALow was significantly higher in patients with a better pathological response (P < 0.001). Furthermore, patients with good pathological response had significantly better prognoses in terms of disease-specific survival (P = 0.014), recurrence-free survival (P = 0.014), and overall survival (P = 0.032). In the multivariate analysis, PLR-CYFRA was an independent predictor of the pathological response of patients with esophageal squamous cell carcinoma to neoadjuvant chemotherapy (P = 0.002). [Conclusion] Pretreatment PLR-CYFRA might be a useful and simple tool that predicts the pathological effect of neoadjuvant chemotherapy in esophageal squamous cell carcinoma

Time-resolved serial femtosecond crystallography reveals early structural changes in channelrhodopsin

X線自由電子レーザーを用いて、光照射によるチャネルロドプシンの構造変化の過程を捉えることに成功. 京都大学プレスリリース. 2021-03-26.Channelrhodopsins (ChRs) are microbial light-gated ion channels utilized in optogenetics to control neural activity with light . Light absorption causes retinal chromophore isomerization and subsequent protein conformational changes visualized as optically distinguished intermediates, coupled with channel opening and closing. However, the detailed molecular events underlying channel gating remain unknown. We performed time-resolved serial femtosecond crystallographic analyses of ChR by using an X-ray free electron laser, which revealed conformational changes following photoactivation. The isomerized retinal adopts a twisted conformation and shifts toward the putative internal proton donor residues, consequently inducing an outward shift of TM3, as well as a local deformation in TM7. These early conformational changes in the pore-forming helices should be the triggers that lead to opening of the ion conducting pore

Odontogenic stem cells

Epithelial cell rests of Malassez (ERM) are quiescent epithelial remnants of the Hertwig’s epithelial root sheath (HERS) that are involved in the formation of tooth roots. ERM cells are unique epithelial cells that remain in periodontal tissues throughout adult life. They have a functional role in the repair/regeneration of cement or enamel. Here, we isolated odontogenic epithelial cells from ERM in the periodontal ligament, and the cells were spontaneously immortalized. Immortalized odontogenic epithelial (iOdE) cells had the ability to form spheroids and expressed stem cell-related genes. Interestingly, iOdE cells underwent osteogenic differentiation, as demonstrated by the mineralization activity in vitro in mineralization-inducing media and formation of calcification foci in iOdE cells transplanted into immunocompromised mice. These findings suggest that a cell population with features similar to stem cells exists in ERM and that this cell population has a differentiation capacity for producing calcifications in a particular microenvironment. In summary, iOdE cells will provide a convenient cell source for tissue engineering and experimental models to investigate tooth growth, differentiation, and tumorigenesis

Nanosecond pump-probe device for time-resolved serial femtosecond crystallography developed at SACLA

X-ray free-electron lasers (XFELs) have opened new opportunities for timeresolved X-ray crystallography. Here a nanosecond optical-pump XFEL-probe device developed for time-resolved serial femtosecond crystallography (TRSFX) studies of photo-induced reactions in proteins at the SPring-8 Angstrom Compact free-electron LAser (SACLA) is reported. The optical-fiber-based system is a good choice for a quick setup in a limited beam time and allows pump illumination from two directions to achieve high excitation efficiency of protein microcrystals. Two types of injectors are used: one for extruding highly viscous samples such as lipidic cubic phase (LCP) and the other for pulsed liquid droplets. Under standard sample flow conditions from the viscous-sample injector, delay times from nanoseconds to tens of milliseconds are accessible, typical time scales required to study large protein conformational changes. A first demonstration of a TR-SFX experiment on bacteriorhodopsin in bicelle using a setup with a droplet-type injector is also presented.112Ysciescopu

肝虚血再灌流障害に対する抗酸化栄養素強化食の保護効果

京都大学0048新制・課程博士博士(医学)甲第21648号医博第4454号新制||医||1034(附属図書館)京都大学大学院医学研究科医学専攻(主査)教授 妹尾 浩, 教授 小池 薫, 教授 Shohab YOUSSEFIAN学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDGA