Formation of an inactive substrate-Cu-Enzyme complex of xanthine oxidase

In the previous papers, it has been shown that the substrate inhibition of xanthine oxidase (xanthine: O2 oxidoreductase, EC 1. 2. 3. 2) induced by excess purines requires a small amount of exogenous metallic ions. Among these ions, Cu&#178;+ was the most typical one. At any stage of enzyme reaction, the inhibition began immediately on addition of a small amount of Cu&#178;+ such as 6.6 X 10-7 M. Since the depressed activity was not restored by the addition of chelating agents such as histamine and EDTA, it was suggested that the substrate, Cu&#178;+ and enzyme form a stable inactive enzyme complex, from which chelating agent can no longer remove Cu. The present communication describes the further investigations concerned with the formation of the substrate-enzyme complex in the presence of Cu&#178;+ and with the catalytic nature of this complex on other substrate and acceptor systems.</p

Immunohistochemical observations of Heat Shock Ptoteins expression in mouse periodontal tissues due to orthodontic mechanical stress

熱ショックタンパク質(HSPs)は熱ショックのみならず、メカニカルストレスに対しても発現する。歯科矯正治療は、関連する歯周組織にメカニカルストレスを付加する。それを受けた後の歯周組織に発現するHSPの状況を調べる事は極めて重要である。そこで今回、我々は歯科矯正学的メカニカルストレスをWaldo法によってddYマウスの歯根膜組織に与え、その後の変化を病理組織学的ならびに免疫組織化学的に検索した。その結果、対象群ではHSP27と70はともに極めて弱い発現であったのに対し、実験群の牽引側歯根膜組織にHSP27と70の両者の発現増強がみられた。これらの所見は、HSPsは歯根膜組織の恒常性の維持に寄与している事を示唆していた。Heat shock proteins (HSPs) are induced by not only the heat shock but also the mechanical stress. Orthodontic tooth movement induced mechanical stress in the related periodontal ligament. It is important to examine the inununohistochemical profile change of the Heat shock proteins (HSPs) in the periodontal ligament cells after receiving the mechanical stress for orthodontic treatment. Therefore, we examined the HSPs in the periodontal ligament cells of ddY mice using the Waldo method. In the control group, periodontal ligament was observed as physiological anangement, and which reacted weakly to HSP27 and HSP70. In the experimental group the extension site of the periodontal ligament cells and the expansion of the blood vessel occuned in the traction side. These tissues were strongly reacted to HSP27 and HSP70. The findings suggeste that the HSPsexpression work as the mechanism of maintenance of homeostasis in the periodontal tissues

National trends in the outcomes of subarachnoid haemorrhage and the prognostic influence of stroke centre capability in Japan: retrospective cohort study

Objectives To examine the national, 6-year trends in in-hospital clinical outcomes of patients with subarachnoid haemorrhage (SAH) who underwent clipping or coiling and the prognostic influence of temporal trends in the Comprehensive Stroke Center (CSC) capabilities on patient outcomes in Japan.Design Retrospective study.Setting Six hundred and thirty-one primary care institutions in Japan.Participants Forty-five thousand and eleven patients with SAH who were urgently hospitalised, identified using the J-ASPECT Diagnosis Procedure Combination database.Primary and secondary outcome measures Annual number of patients with SAH who remained untreated, or who received clipping or coiling, in-hospital mortality and poor functional outcomes (modified Rankin Scale: 3–6) at discharge. Each CSC was assessed using a validated scoring system (CSC score: 1–25 points).Results In the overall cohort, in-hospital mortality decreased (year for trend, OR (95% CI): 0.97 (0.96 to 0.99)), while the proportion of poor functional outcomes remained unchanged (1.00 (0.98 to 1.02)). The proportion of patients who underwent clipping gradually decreased from 46.6% to 38.5%, while that of those who received coiling and those left untreated gradually increased from 16.9% to 22.6% and 35.4% to 38%, respectively. In-hospital mortality of coiled (0.94 (0.89 to 0.98)) and untreated (0.93 (0.90 to 0.96)) patients decreased, whereas that of clipped patients remained stable. CSC score improvement was associated with increased use of coiling (per 1-point increase, 1.14 (1.08 to 1.20)) but not with short-term patient outcomes regardless of treatment modality.Conclusions The 6-year trends indicated lower in-hospital mortality for patients with SAH (attributable to better outcomes), increased use of coiling and multidisciplinary care for untreated patients. Further increasing CSC capabilities may improve overall outcomes, mainly by increasing the use of coiling. Additional studies are necessary to determine the effect of confounders such as aneurysm complexity on outcomes of clipped patients in the modern endovascular era