【目的】筋力増強に加えバランス能力向上を目的としたバランスボード（以下BB）上での下肢CKC（closed kinetic chain）トレーニングは臨床上よく行われている。しかし、BB上でのCKC動作時の筋活動量について、筋電図学的な側面から検討している報告は少ない。本研究の目的は、代表的なCKCトレーニングであるスクワットおよび片脚スクワットを床面とBB上で行い、その際の筋活動量を比較することである。
【対象・方法】対象は健常成人男性12名（平均年齢28.2±4.5歳、平均身長170.6±6.3cm、平均体重64.2±8.7kg）とした。対象者には本研究の趣旨と目的を説明し、同意を得た。測定筋は大腿直筋(RF)・内側広筋(VM)・大殿筋(GM)・内側ハムストリングス(MH)・前脛骨筋(TA)・腓腹筋(GC)およびヒラメ筋(SO)とした。スクワットおよび片脚スクワットは体幹直立位・膝関節屈曲60°に固定した静的な肢位とし、床面およびBB上でそれぞれ姿勢が安定してから3秒間の筋電図を測定した。なお、BBには（ Fitness社製）を用いた。は半球状のBBであり、半球を上にした場合（表）と下にした場合（裏）とに分けて測定した。測定値は各筋の最大随意収縮時のRoot Mean Square(RMS)振幅値を100%として正規化し、%RMSとして表した。統計には、反復測定分散分析を用い、有意差が生じた場合Scheffeの多重比較を行った。
【結果】スクワット・片脚スクワット両動作ともに、RF・VMを除き、各筋において床面よりも表・裏で筋活動量が有意に増加した。なかでもTA、GC、SOの筋活動量が大きく増加した。スクワット床面と表を比較すると、TAは1.7%→33.2%、GCは5.3%→14.7%RMS、SOは15.8%→28.3%へと筋活動量はそれぞれ増加し、片脚スクワットでも同様にTAは9.3%→36.7%、GCは11.6%→32.2%、SOは31.5%→58.2%へと増加した。GM・MHの筋活動量は表での片脚スクワット時に有意な増加を示したが、それぞれ12.1%RMS、12.4%RMSにとどまった。一方、RF・VM筋活動量は床面と表・裏との間に有意差は生じなかった。また、表と裏での筋活動量の比較では、表での動作時に筋活動量が高い傾向はあるものの、スクワットでのGM・TAを除き有意差は生じなかった。
【考察】床面よりもBB上でのスクワット・片脚スクワット動作において、有意な筋活動量の増加を示し、かつ、高い筋活動量を示したのは足関節底背屈筋であるTA・GC・SOであった。このことから、不安定な支持面上で静的な姿勢を保持するために足関節底背屈筋の筋活動量が増加したと考えられ、姿勢コントロールにおける足関節の重要性が示唆された。一方、膝関節角度を固定した静的なスクワット動作のため、膝関節周囲筋の筋活動量に有意差は生じなかったと考えられる。
【まとめ】BB上での静的なCKCトレーニングでは足関節周囲筋の筋活動量を増加させることが明らかとなった。

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週1回，12週間継続する水中ウォーキング教室に参加する中高年女性を対象として，水中ウォーキング継続の効果を，教室に参加しない同年代女性を対照群として比較検討した．1回50分間の水中ウォーキング教室は，水温29 °Cのプールで，熟練したインストラクターによって指導された．心拍数を運動開始前から運動中に測定し，求めた50分間の運動中の平均心拍予備率は24～34%であり，低―中等度強度の運動と考えられた．Mood check list-short form 1による運動前後の感情測定の結果，教室1週目から快感情得点とリラックス感得点が直前に比べ運動後に向上し，12週目も同様であった（P<0.001）．教室1週目と12週目に健脚度関連体力を測定した結果，最大1歩幅，片足スクワット，バランステスト，10 m全力歩行が改善した．また，冬道歩行のセルフエフィカシー得点では強風下歩行と凍結路歩行における自信の向上が教室1週目に比べ12週目に示唆された．このような変化は対照群では認められなかった．

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本研究は，週2回，12週間継続する「水中運動教室」に参加した運動群15名と，運動しない対照群16名の60歳以上女性を対象とした．1回60分間の水中運動は，水温34 °Cのプールで，熟練したインストラクターによって指導された．教室開始時と終了時に体格，健脚度関連体力，転倒と冬道歩行のセルフエフィカシー（SE）及び精神的健康度とquality of life（QOL）に関する測定を行った．その結果，運動群のbody mass index（BMI）と体脂肪率の低下及びバランス能力の改善は有意であったが，上体起こしと最大1歩幅には改善がみられなかった．運動群では，転倒及び冬道歩行のSE総合得点は有意に改善したが，転倒あるいは冬道歩行SE尺度単独では有意でなく，対照群においてはいずれも変化がなかった．ストレス尺度得点に両群とも有意な変化がなく，水中運動教室への参加が運動群の新たなストレス負担とは認められなかった．QOL調査では，運動群の身体症状とQOL平均値に有意な改善が見られた．

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  Co₂Fe_xMn_1-xSi (CFMS) is one of the most attractive highly spin-polarized materials since large tunnel magneto-resistance and giant magneto-resistance have been recenltly observed in the devices using CFMS electrodes. In this study, we investigated the dependence of CPP-GMR in CFMS/Ag/CFMS on Fe composition x and annealing temperature T_ann for CFMS electrodes. The highest intrinsic MR ratio of 55% and ΔRA of 17.2 mΩ•μm² were achieved at x = 0.5 and T_ann = 550°C. Finally, we compared the results on CPP-GMR with those on TMR, anisotropic magneto-resistance and damping constant for CFMS and discussed half-metallicity of CFMS.

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  The Magnetic structure of magnetic multilayers composed of a full Heusler Co₂MnSi(CMS) alloy and Cr was calculated by using first-principles band calculation. We found that the magnetic moments of Co and Cr were parallel, while those of Mn and Cr were anti-parallel in CMS/Cr/CMS multilayers. By comparing the calculated results with those in Fe/Cr/Fe multilayers, it could be argued that the magnetic structure calculated for Co, Mn, and Cr atoms is crucial for the biquadratic coupling observed in these multilayers.

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To examine the ovarian response to Arcanobacterium pyogenes (A. pyogenes) in uterus, bacterial solution was infused into the uteri of cows, and the follicle and corpus luteum (CL) development were monitored with a real-time ultrasound instrument. In addition, the plasma concentrations of progesterone (P₄) and 13, 14-dihydro-15-keto-PGF_2α (PGFM) were determined. A 10 ml bacterial solution that contained A. pyogenes (8 to 15 × 10⁸ CFU/ml) was infused into the uterus of eight cows transcervically three days after natural ovulation. As a control, sterile physiological saline was infused into 4 other cows. The dominant follicle developed normally in 8 cows after bacteria inoculation. In 4 of these 8 cows, the developing CL regressed, and the first wave dominant follicles, which normally become atretic, ovulated after the inoculation. In the remaining 4 cows, the CL did not regress. The PGFM concentration increased transiently in all 8 cows after the infusion. The mean PGFM concentration of the cows with a regressed CL was significantly lower (P<0.01) than that of the cows whose CLs did not regress. In the control cows, there was no regression of developing CLs, no ovulation of first wave dominant follicles and no transient increase in PGFM after the infusion of sterile physiological saline. These results show that infusion of A. pyogenes into the uterus did not affect folliculogenesis and might have induced PGF_2α production from the uterus.

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Objectives of this study were to show postpartum plasma PGF_2α metabolite (PGFM) profile, to clarify whether endogenous PGF_2α plays a certain role in the uterine involution in cows with dystocia and/or retained placenta, and to examine the effects of fenprostalene, a long-acting PGF_2α analog, on the uterine involution and reproductive performance of the cows with abnormal puerperium. A group of 27 cows with dystocia and/or retained placenta showed a massive release of PGF_2α after parturition as indicated by a rise of plasma concentrations of PGFM, significantly higher than 33 cows with normal puerperium. The duration of the elevated plasma PGFM concentrations in the cows with abnormal puerperium was shorter than that of the normal cows. In cows with normal puerperium, those showing relatively longer duration of elevated plasma PGFM levels needed a shorter period for postpartum uterine involution than the cows showing a shorter duration of the PGFM elevation (P<0.01), while no such relationship was observed in cows with abnormal puerperium. In field trials, an administration of an exogenous PGF_2α, fenprostalene, at 7 to 10 days (78 cows) or 14 to 28 days postpartum (74 cows) was found to be effective in facilitating uterine involution and resumption of ovarian cyclicity, and improved reproductive performance. It may be concluded that a large amount of PGF_2α is released for a relatively shorter period in cows after dystocia and/or retained placenta and the elevation of PGFM is not responsible for the uterine involution. The administration of the exogenous PGF_2α was shown to be effective at improving the postpartum reproductive performance of cows with abnormal puerperium.

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Ovariectomized goats were implanted with the electrode arrays for monitoring the electrophysiological manifestation of the activity of the hypothalamic gonadotropin-releasing hormone (GnRH) pulse generator, namely multiple-unit activity (MUA) volleys associated with pulsatile luteinizing hormone secretion. They were then subjected to i.v. challenges of lipopolysaccharide (LPS) at the dose of 200 or 400 ng/kg. The interval between the MUA volleys was significantly prolonged by higher dose of LPS whereas neither amplitude nor duration of the MUA volleys was altered. These results suggest that immunological disturbance as evoked by LPS administration directly affects the hypothalamic GnRH pulse generator by slowing down the pulse frequency, and thereby lowers gonadotropin secretion from the anterior pituitary gland, which would culminate in gonadal suppression.

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The objectives of this study were to determine the risk factors for development of postpartum ovarian cysts by evaluating several reproductive factors in individual cows, and to determine the economic impact of ovarian cysts on subsequent reproductive performance in dairy herds in Korea. The data, including cow parity, abnormal puerperium, endometritis, body condition score (BCS), and breeding status were collected from 634 cows in 9 dairy herds. We used logistic regression to evaluate the effects of these factors on ovarian cysts. A stepwise procedure, used to obtain the appropriate model with α=0.05, revealed that cow parity was the most important risk factor for ovarian cyst development within 8 weeks postpartum, while development of endometritis and BCS loss ≥1 from the dry period to 8 weeks postpartum were the most important risk factors for ovarian cyst development beyond 8 weeks postpartum. The occurrence of ovarian cysts beyond 8 weeks postpartum prolonged (P<0.01) the mean intervals from calving to first service (27 days) and conception (77 days), and increased (P<0.05) the culling rate (7.8%), while ovarian cyst development within 8 weeks postpartum did not affect (P>0.05) the mean intervals from calving to first service and conception or the culling rate. The economic loss resulting from the occurrence of ovarian cysts was estimated at approximately 823,996 won ($687) due to effects on the cost of nutrition, average growth of calves, labor and medical costs, and culling. These results suggest that cow parity is correlated with the development of ovarian cysts within 8 weeks postpartum, and endometritis and BCS loss ≥1 from the dry period to 8 weeks postpartum are correlated with the development of ovarian cysts after 8 weeks postpartum, which decreases reproductive performance and results in economic loss in dairy herds in Korea.

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A 21 year old thoroughbred mare with granulosa theca cell tumor (GTCT) in the right side and atrophic contralateral ovary was investigated in this study. After arrival at our laboratory on 10th December 1999, the clinical diagnosis of GTCT was examined by rectal palpation and ultrasonographic image of ovaries. Plasma from peripheral blood was collected in the breeding and non-breeding seasons for hormonal analysis. The results showed that the contralateral ovary regained normal activity without any treatment of the GTCT affected ovary and contained follicles showing different sizes 19 months later. However, the affected right ovary, which became smaller after 4 months, was totally inactive without any follicle. The observations clearly demonstrate that without any treatment of the GTCT affected ovary, a mare can return to her normal estrous cycle within a certain period in some GTCT cases.

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[Purpose] To determine the effects of progressive neuromuscular training on postural balance and functionality in elderly patients with knee osteoarthritis (OA). [Subjects and Methods] Eleven participants between 60 and 75 years of age performed the progressive neuromuscular training for 8 weeks and 4 weeks of follow-up. The area and velocity of the center of pressure were measured on a force platform, and the functionality was measured with a Western Ontario and McMaster Universities Osteoarthritis Index. [Results] The area and velocity (anteroposterior and mediolateral directions) of the center of pressure showed significant differences after 4 and 8 weeks of intervention. Additionally, the global score and some questionnaire dimensions (pain and physical function) showed significant differences after 4 and 8 weeks of intervention. These changes were maintained in all variables at week 4 of follow-up. [Conclusion] The intervention generated improvements in balance and functionality in elderly patients with knee OA. These changes were observed after 4 weeks of training and were maintained 4 weeks after the end of the intervention.

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[Purpose] Force production during a squat action on a rotational resistance device (RRD) under stable and unstable conditions. [Subjects and Methods] Twenty-one healthy males were asked to perform six sets of six repetitions of squats on an RRD on either stable or unstable surfaces. The stable and unstable sets were performed on different days. Muscular outputs were obtained from a linear encoder and a strain gauge fixed to a vest. [Results] Overall, the results showed no significant differences for any of the dependent variables across exercise modes. Force_mean outputs were higher in the concentric phase than in the eccentric phase for each condition, but there were no differences in velocity, time or displacement. The force_peak was similar in the eccentric and concentric phases of movement under both stable and unstable conditions. There were no significant differences in force_mean between sets per condition or between conditions. [Conclusion] These results suggest that performing squats with a RRD achieves similar force_mean and force_peak under stable and unstable conditions. The force_peak produced is also similar in concentric and eccentric phases.

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MgAl_2O_4基板(MAO基板)はホイスラー合金との格子ミスマッチが1%以下と非常に小さいため、MgO基板と比較して界面欠陥の少ないコヒーレントな薄膜成長が可能になる。そのため、基板によって起きる薄膜中の欠陥などの影響を排除することが可能であり、ホイスラー合金の磁気特性に及ぼすひずみの影響や、人工格子における界面電子構造などの評価に最適である。また、磁気トンネル接合のバリア層として用いることで界面でのスピン緩和が抑制されると期待される。本研究では、格子整合系MgAl_2O_4/ホイスラー合金積層構造の磁気特性、電子構造、磁気伝導特性と結晶構造の相関を系統的に調べた結果を報告する。

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To investigate how uterine inflammation affects ovarian activity in rats, endometritis was induced and changes in the length of estrous cycle and serum concentrations of estradiol-17β (E₂) and progesterone (P₄) were examined. A suspension of Staphylococcus aureus (bacterial solution) or iodine solution was infused into the uterine lumen at various estrous phases. When the bacterial solution was infused at estrus, metestrus, or the first day of diestrus, the following diestrus continued for 5 to 12 days. In the case of the iodine solution, regardless of the estrous phase of the infusion, the following diestrus continued for approximately 6 days. E₂ concentration after infusion of each solution did not fluctuate largely and remained at a low concentration (around 5 pg/ml). P₄ concentration was high (35-45 ng/ml) on the day following infusion, but decreased rapidly to base line values within a few days and remained thereafter at a low level (around 5 ng/ml). It is assumed that the endometritis caused by biological or chemical stimulation raises the concentration of P₄ to depress gonadotrophic hormone secretion, and hence this high P₄ concentration might inhibit the growth of ovarian follicles.

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