温熱療法は筋疲労を予防するか ―温熱負荷が筋細胞のエネルギー代謝、Caイオン動態に及ぼす影響―

背景 　デスクワークの増加やスマートフォンの頻用により、肩こりや腰痛、眼精疲労などの筋疲労が増加している。その回復方法として温熱療法がよく用いられ、血流の改善や神経系のリラックス効果が報告されているが、筋肉への直接的な効果は明らかにされていない。 目的　温熱療法が直接筋肉に作用して疲労を予防するかを、C2C12（マウス骨格筋由来筋芽細胞）の温熱負荷モデルを用い、温熱が筋細胞のエネルギー代謝とCaイオン動態に及ぼす影響から検討した。 方法、結果 　42℃での細胞培養は、C2C12に熱ショック蛋白70を誘導したことより、温熱負荷が筋細胞に直接作用し、ストレス応答を惹起することが示された。温熱負荷は、ミトコンドリアの好気的代謝を亢進し、嫌気的代謝による乳酸産生を抑制した。また、温熱負荷は筋小胞体のATP依存性Caポンプを活性化し、細胞質から小胞体へのCaイオンの回収を促進した。 結論　以上より、温熱負荷は筋細胞のエネルギー産生効率を上昇させ、細胞質のCaイオン濃度を低下させることにより、弛緩を促進することが明らかとなった。従って、温熱療法は筋細胞のエネルギー産生とCaイオン動態に直接作用することにより、筋疲労を回復させる可能性が示唆された。Rationale Increases in VDT work and smartphone use increase the incidence of muscle fatigue, such as lower back pain, shoulder stiffness, and asthenopia. Thermotherapy is frequently used to recover from muscle fatigue. It is supposed to improve blood flow and to induce neurological relaxation. However, whether hyperthermia directly affects the physiology of muscle cells is not elucidated. Objectives To investigate the direct effect of thermotherapy on muscle tissue, I examined the effect of hyperthermia on energy metabolism and Ca ion movement of cultured C2C12, myoblast cells isolated from mouse skeletal muscle tissue. Methods and results Cell culture at 42° Cinduced heat shock protein 70(HSP70) in C2C12 indicates that hyperthermia affected directly on the muscle cells and caused stress response. Hyperthermia augmented aerobic metabolism in mitochondria and decreased lactate production by anaerobic metabolism in the cytosol. Ca ion uptake to the endoplasmic reticulum by ATP dependent Ca pump was also promoted by hyperthermia. Conclusions These results indicate that hyperthermia improves the efficiency of energy metabolism and Ca ion movement of muscle cells directly and promotes muscle relaxation. Therefore, thermotherapy is supposed to improve muscle fatigue through the improvement of energy metabolism and Ca ion handling of muscle tissue

Fault tolerant packet-switched network design and Its sensitivity

Reliability and performance for telecommunication networks have traditionally been investigated separately in spite of their close relation. A design method integrating them for a reliable packet switched network, called a proofing method, is presented. Two heuristic design approaches (max-average, max-delay-link) for optimizing network cost in the proofing method are described. To verify their effectiveness and applicability, they are compared numerically for three example network topologies. The sensitivity of these two methods is examined with respect to changes in traffic demand and in link reliability. The design sensitivity to variation of input data is examined by changing the predicted probability of link failure, and by increasing the network traffic over the predicted value. The resulting analysis shows relative insensitivity of solutions generated by the two design methods to input data</p

神戸女学院大学での体験型実習を利用した高大接続の試み

Japanese college accepted diverse type of students through various methods of entrance examination. Therefore, each college students have highly heterogeneous background and some of them are not familiar even with the admisson policy of their college. These students encounter the dissociation between the image and the real aspects of college life and will leave their college in high rate. To avoid the withdrawal of students from their college due to mismatch, we are offering three programs to high school students, high school teachers, and freshmen using our science laboratories. In these programs we are trying to inform the admission policy of Department of Biosphere Sciences to our future students and their teachers and also trying to confirm our policy in the statistical efficacy of these programs

環境・バイオサイエンス学科におけるリメディアル教育の必要性とBlackboardシステム利用の試み

Recently, we renovated the entrance examinations of the Department of Biosphere Sciences, due to the reduction of high school students and the diversity of them. However, the renovation might have reduced the chance to test scientific ability and knowledge of examinees. Therefore, we examined the percentage of students who completed chemistry and biology courses of high school in freshmen of the year 2005. Although only 19% were evaluated by the examination of chemistry and biology, more than 50% were assigned to science courses of high school. Furthermore, nearly 90% of them took basic courses of chemistry and biology. We also tested e-learning system, Blackboard, in several middle to large classes of biological sciences. Students joined e-learning class through intranet of college campus and through internet from their home, if incentives, such as percentage in the final score, were high. However, they were not familiar with Blackboard because of the small number of class involved in Blackboard. That is the problem of teachers who would not use Blackboard, because it needs much effort to start Blackboard class, at least for the beginning. In 2006, we will receive students who graduated from high school under "the new course of learning" which were blamed for its reduced learning material. Therefore, we have to prepare for them by trying every tools that is helpful for the remedial teaching

The Role of Apelin on the Alleviative Effect of Angiotensin Receptor Blocker in Unilateral Ureteral Obstruction-Induced Renal Fibrosis

Background: Apelin is a selective endogenous ligand of the APJ receptor, which genetically has closest identity to the angiotensin II type 1 receptor (AT-1). The effects of the apelin/APJ system on renal fibrosis still remain unclear. Methods: We examined the effects of the apelin/APJ system on renal fibrosis during AT-1 blockade in a mouse unilateral ureteral obstruction (UUO) model. Results: We obtained the following results: (1) At UUO day 7, mRNA expressions of apelin/APJ and phosphorylations of Akt/endothelial nitric oxide synthase (eNOS) in the UUO kidney were increased compared to those in the nonobstructed kidney. (2) AT-1 blockade by the treatment with losartan resulted in a further increase of apelin mRNA as well as phosphorylations of Akt/eNOS proteins, and this was accompanied by alleviated renal interstitial fibrosis, decreased myofibroblast accumulation, and a decreased number of interstitial macrophages. (3) Blockade of the APJ receptor by the treatment with F13A during losartan administration completely abrogated the effects of losartan in the activation of the Akt/eNOS pathway and the amelioration of renal fibrosis. (4) Inhibition of NOS by the treatment with L-NAME also resulted in a further increase in renal fibrosis compared to the control group. Conclusion: These results suggest that increased nitric oxide production through the apelin/APJ/Akt/eNOS pathway may, at least in part, contribute to the alleviative effect of losartan in UUO-induced renal fibrosis

ERK Regulates Renal Cell Proliferation and Renal Cyst Expansion in inv Mutant Mice

Nephronophthisis (NPHP) is the most frequent genetic cause of end-stage kidney disease in children and young adults. Inv mice are a model for human nephronophthisis type 2 (NPHP2) and characterized by multiple renal cysts and situs inversus. Renal epithelial cells in inv cystic kidneys show increased cell proliferation. We studied the ERK pathway to understand the mechanisms that induce cell proliferation and renal cyst progression in inv kidneys. We studied the effects of ERK suppression by administering PD184352, an oral mitogen-activated protein kinase kinase (MEK) inhibitor on renal cyst expansion, extracellular signal-regulated protein kinase (ERK) activity, bromo-deoxyuridine (BrdU) incorporation and expression of cell-cycle regulators in invΔC kidneys. Phosphorylated ERK (p-ERK) level increased along with renal cyst enlargement. Cell-cycle regulators showed a high level of expression in invΔC kidneys. PD184352 successfully decreased p-ERK level and inhibited renal cyst enlargement. The inhibitor also decreased expression of cell-cycle regulators and BrdU incorporation in renal epithelial cells. The present results showed that ERK regulated renal cell proliferation and cyst expansion in inv mutants

肺胞マクロファージの炎症反応に及ぼすニコチンの影響

Cigarette smoke contains more than 4,000 chemical substances and causes deleterious effects on various human organs. As the lung is the first organ that is exposed to these substances, cigarette smoking induces respiratory diseases such as inflammation, remodeling and cancer in high incidence. We examined whether nicotine, one of the major bioactive substances in cigarette smoke, disrupts lung immune function against respiratory diseases. We tested the effect of nicotine on antimicrobial activity of alveolar macrophages (AMs) by evaluating nitric oxide (NO) production and phagocytosis. NO production was assessed by measuring N0_2^-/N0_3^-concentration using Griess reagent method and phagocytosis was evaluated by the intake of fluoroprobe-labeled latex beads. Rat AM harvested by blonchoalveolar lavage (BAL) and mouse AM cell line (AMJ2-C11) were treated with 0-500μM of nicotine for 24h. Nicotine in high concentration (250, 500μM) enhanced phagocytosis of latex beads in both AMs significantly. In addition, the high concentration of nicotine (over 100μM) increased NO production by AMs. These results suggeste that nicotine enhances inflammatory function of AMs in high concentration. The over activation of inflammatory response by nicotine may contribute to the induction of respiratory injury by cigarette smoking

成熟マウス心筋細胞の単離と模擬虚血モデルの作成

Cultured cells are used for biochemical and physiological investigation of organ system, because they can supply relatively uniform experimental models. Cardiac myocytes have been also isolated and cultured for the use of heart studies. However, adult cardiac myocytes are sensitive to isolation condition and most studies utilized fetal or neonatal cardiac myocytes. Recently, several groups isolated adult cardiac myocytes from canine, rabbit and rat successfully. In this report, we tried to isolate myocytes from adult mice and to establish oxidative stress model of adult mouse myocytes. Hearts were excised and retro-perfused through aorta by collagenase solution following physiological salt solution containing uncoupler of excitation-contraction coupling, butanedione. Thereafter, hearts were minced in 1-2mm^3 cube and myocytes were isolated by mechanical agitation. Isolated cells were transferred onto culture dishes pre-coated with laminine. Cells were cultured with Dulbecco\u27s modified Eagle medium containing 10% fetal bovine serum and bromodeoxyuridine. Isolated myocytes showed rod shape with striation, typical morphology of adult cardiac myocytes. They attached on laminine-coated dishes and survived over 5 days without proliferation of contaminated noncardiac myocytes. When cells were cultured more than a week, they changed their shape to spindle type and started spontaneous beating. To mimic oxidative stress to hearts, we added hydrogen peroxide to myocyte cultures. Myocytes released lactate dehydrogenase into culture medium dose and time dependently. These data suggest that we successfully isolated and cultured cardiac myocytes from adult mouse hearts. They showed similar characteristics to the heart in situ in oxidative stress model by hydrogen peroxide