Association between Oral Health Conditions and Nutritional Status in Hemodialysis Patients

近年透析患者の高齢化が進んでおり，透析患者における低栄養と生命予後の関連が報告されている．低栄養の主な原因は食事摂取量の低下と考えられているが，これまでの研究で歯科的要因の関与については十分に検討されていない．本研究では，透析患者の栄養状態と現在歯数および咬合支持状態との関連を明らかにすることを目的として，透析医療機関に併設する歯科口腔外科を受診した透析歴1 年以上の血液透析患者155 名を対象に歯科初診時の口腔状態と直近の栄養指標を横断的に調査し，その関連性について統計学的に検討した．その結果，現在歯数および健全歯根膜表面積より算出される咬合支持能力指数（Normal Periodontal Ligament Index: NPLI）と標準化蛋白異化率（normalized protein catabolic rate: nPCR）の間に有意な正の相関を認めた（Spearman 順位相関係数検定，p<0.05）．また，Eichner分類で群分けした場合（A 群 vs B/C 群），nPCR は2 群間で有意な差を認めた（0.97±0.20 vs 0.90±0.17, スチューデントt 検定，p=0.023）．さらに，二項ロジスティック回帰分析の結果，nPCR が0.8 未満であることに現在歯数やEichner 分類B/C 群が関連することが示された（それぞれオッズ比（95% 信頼区間），p 値：0.945（0.907–0.985）， p=0.007，2.464（1.079–5.626），p=0.032）．nPCR はタンパク質摂取量を反映する指標であることから，血液透析患者において歯の喪失や不十分な咬合支持状態がタンパク質摂取不足に繋がる可能性が示唆された．本研究の結果から，血液透析患者の低栄養のリスクとして，歯数や咬合支持など口腔環境を考慮する必要があることが示唆された．Recently, concerns over malnutrition in hemodialysis patients have been highlighted, along with the aging of patients. The most important cause of malnutrition in hemodialysis patients is considered to be an inadequate dietary intake. However, the involvement of oral health conditions in the malnutrition of hemodialysis patients has not been fully elucidated. The aim of this study was to clarify the relationships between oral health conditions [number of remaining natural teeth and occlusion status] and nutritional status in hemodialysis patients. We evaluated and analyzed oral health conditions [number of remaining natural teeth and occlusion status] and the nutritional status of patients at their first visit to the Department of Oral Surgery in a hemodialysis hospital. 　We found significant correlations between the number of remaining teeth or occlusion status and normalized protein catabolic rate (nPCR). Significant differences between groups divided according to the Eichner index (Group A vs. Group B/C) were also found (0.97±0.20 vs. 0.90±0.17, respectively, Student’s t-test, p=0.023). Moreover, logistic regression analysis suggested that nPCR could be attributed to the number of remaining natural teeth and Eichner index (OR=0.945, 95% CI: 0.907-0.985; p=0.007 and OR=2.464, 95% CI: 1.079-5.626; p=0.032, respectively). Since nPCR is an indicator used for monitoring protein intake, tooth loss and an inadequate occlusion status might lead to decreased protein intake in hemodialysis patients. These results suggest that it is necessary to consider the number of remaining natural teeth and occlusion status as risks of malnutrition in hemodialysis patients

Crystal structure of the hemolytic lectin CEL-III isolated from the marine invertebrate Cucumaria echinata : Implications of domain structure for its membrane pore-formation mechanism

CEL-III is a Ca^＋ -dependent and galactose-specific lectin purified from the sea cucumber, Cucumaria echinata, which exhibits hemolytic and hemagglutinating activities. Six molecules of CEL-III are assumed to oligomerize to form an ion-permeable pore in the cell membrane. We have determined the crystal structure of CEL-III by using single isomorphous replacement aided by anomalous scattering in lead at 1.7 Å resolution. CEL-III consists of three distinct domains as follows: the N-terminal two carbohydrate-binding domains (1 and 2), which adopt β-trefoil folds such as the B-chain of ricin and are members of the (QXW)_3 motif family; and domain 3, which is a novel fold composed of two α-helices and one β-sandwich. CEL-III is the first Ca^ -dependent lectin structure with two β-trefoil folds. Despite sharing the structure of the B-chain of ricin, CEL-III binds five Ca^ ions at five of the six subdomains in both domains 1 and 2. Considering the relatively high similarity among the five subdomains, they are putative binding sites for galactose-related carbohydrates, although it remains to be elucidated whether bound Ca^ is directly involved in interaction with carbohydrates. The paucity of hydrophobic interactions in the interfaces between the domains and biochemical data suggest that these domains rearrange upon carbohydrate binding in the erythrocyte membrane. This conformational change may be responsible for oligomerization of CEL-III molecules and hemolysis in the erythrocyte membranes.This research was originally published in Journal of Biological Chemistry. Tatsuya Uchida, Takayuki Yamasaki, Seiichiro Eto, Hajime Sugawara, Genji Kurisu, Atsushi Nakagawa, Masami Kusunoki and Tomomitsu Hatakeyama. Crystal structure of the hemolytic lectin CEL-III isolated from the marine invertebrate Cucumaria echinata : Implications of domain structure for its membrane pore-formation mechanism. Journal of Biological Chemistry. 2004; 279, 37133-37141. © the American Society for Biochemistry and Molecular Biology

A nucleoside anticancer drug, 1-(3-C-ethynyl-β-D-ribo-pentofuranosyl)cytosine (TAS106), sensitizes cells to radiation by suppressing BRCA2 expression

<p>Abstract</p> <p>Background</p> <p>A novel anticancer drug 1-(3-C-ethynyl-β-D-ribo-pentofuranosyl)cytosine (ECyd, TAS106) has been shown to radiosensitize tumor cells and to improve the therapeutic efficiency of X-irradiation. However, the effect of TAS106 on cellular DNA repair capacity has not been elucidated. Our aim in this study was to examine whether TAS106 modified the repair capacity of DNA double-strand breaks (DSBs) in tumor cells.</p> <p>Methods</p> <p>Various cultured cell lines treated with TAS106 were irradiated and then survival fraction was examined by the clonogenic survival assays. Repair of sublethal damage (SLD), which indicates DSBs repair capacity, was measured as an increase of surviving cells after split dose irradiation with an interval of incubation. To assess the effect of TAS106 on the DSBs repair activity, the time courses of γ-H2AX and 53BP1 foci formation were examined by using immunocytochemistry. The expression of DNA-repair-related proteins was also examined by Western blot analysis and semi-quantitative RT-PCR analysis.</p> <p>Results</p> <p>In clonogenic survival assays, pretreatment of TAS106 showed radiosensitizing effects in various cell lines. TAS106 inhibited SLD repair and delayed the disappearance of γ-H2AX and 53BP1 foci, suggesting that DSB repair occurred in A549 cells. Western blot analysis demonstrated that TAS106 down-regulated the expression of BRCA2 and Rad51, which are known as keys among DNA repair proteins in the homologous recombination (HR) pathway. Although a significant radiosensitizing effect of TAS106 was observed in the parental V79 cells, pretreatment with TAS106 did not induce any radiosensitizing effects in BRCA2-deficient V-C8 cells.</p> <p>Conclusions</p> <p>Our results indicate that TAS106 induces the down-regulation of BRCA2 and the subsequent abrogation of the HR pathway, leading to a radiosensitizing effect. Therefore, this study suggests that inhibition of the HR pathway may be useful to improve the therapeutic efficiency of radiotherapy for solid tumors.</p

Receptor Autoradiographic Analysis of Muscarinic Receptors in the Rat Atrioventricular Node

We carried out investigations on muscarinic acetylcholine receptors (m-AChR) in the rat heart, including the atrioventricular (AV) node. The related tissue sections were incubated with 3H-quinuclidinyl benzilate (3H-QNB), then autoradiography and an image analysis coupled with computer-assisted microdensitometry were done. A single type of specific and high affinity binding sites of 3H-QNB was found to be highly concentrated in the AV node, the maximum binding capacity (Bmax) being 1.4 pmol/mg protein and with a dissociation constant (Kd) of 0.5 nM. The density and affinity of the binding to the AV node were the highest, when compared with findings in the atrium (interatrial septum) and ventricle (interventricular septum). The binding was competitively displaced by AF-DX 116, a selective antagonist for the M2 AChR subtype, with a high affinity, whereas pirenzepine, an antagonist for the M1 AChR subtype was much less potent in displacing the binding. Therefore, vagal-cholinergic stimulation presumably plays a significant role in functions of the rat AV node, probably by interacting with the specific, high affinity M2 AChR subtype

Results and Issues in Student Teaching Program for Freshman at Okayama University on 2011

本研究の目的は，岡山大学教育学部における1年次の教育実習プログラムの成果と課題の検討であった。そのため，平成23年度の教育実習Ⅰ受講生294名を対象に実習後に調査を行った。その結果，（１）教育実践力を構成する4つの力や附属学校園における実習目的の多くが達成されている，（２）4つの力のうち「コーディネート力」「生徒指導力」の達成度が特に高く，「学習指導力」の学校種ごとの学習指導の特徴や違いを説明することは達成度が低い，（３）附属学校園が掲げる目的のうち，観察して学ぶことの達成度が高いが，実際に児童生徒 と関わって学ぶことの達成度は低い傾向である，（４）実習中の実習生の取り組みに関しては，授業観察において事実を観察，記録することは取り組めているが，解釈的な授業観察や，協議会での発言は十分取り組めていない，の4点が主に示唆され，実習Ⅰの課題や不安に対する学生の自由記述と併せて結果が考察された