The Influence on Limbs and Trunk muscles in Lifting a Weight at Different Platform Levels

重量物の持ち上げ動作において,荷台の高さの違いが四肢体幹筋に及ぼす影響を調べるために,筋電計を用いて実験を行った.対象は,筋骨格系障害の既往がない健常男子大学生10名(平均年齢22.2±0.9才,平均身長169.9±4.3㎝,平均体重62.3±4.0㎏)であった.被験筋は,持ち上げ動作に重要な僧帽筋,上腕二頭筋,脊柱起立筋,大腿直筋とした.荷台の高さを身長の40%,50%,60%に設定し,重量物の質量は体重の30%とし床面から荷台へ合計10回荷揚げさせた.得られた筋電波形のIEMGを求め,しゃがみ込み開始から重量物の離床まで(以下Prepare-Periodと略)と,重量物の離床から重量物の着床まで(以下Carrying-Periodと略)に分けて分析した結果,各荷台高においてPrepare-Periodでは荷台の上昇に伴い僧帽筋と大腿直筋の働きが大きくなることが認められた.また,Carrying-Periodにおいても荷台の上昇に伴い僧帽筋と大腿直筋が他の筋より大きな値となり,重量物の高位への持ち上げに重要な働きをすることが示唆された.The Influence on Limbs and Trunk muscles in Lifting a Weight at Different Platform LevelsMasahiko. Fujimura, Isao Nara, Mitsutoshi KawamuraInstitute of Health Sciences, Hiroshima University Faculty of MedicineThe purpose of this study is to examine the influence on limbs and trunk muscles in lifting a weight at different platform levels. This is to report a basic study on the muscle activity data with the use of surface EMG and the calculated integrated EMG (IEMG) value. Ten male university students (average age 22.2±0.9 years, average height 169.9±4.3cm, average weight 62.3±4.0kg) who were healthy and had no history of disorders participated in this study . The subject lifted up a weight 10 times. (The weight used in this study was adjusted to 300f subjects weight and the platforms levels were set at the height of 40%, 50-0x1.4aa00bfffa2ep-149nd 6026651131640f subjects height.) Surface EMG were collected from trapezius, biceps brachii, elector spinae, rectus femoris by electromyograph (Myosystem1200, Noraxon USA). Set the term "Prepare-Period" is the squatting motion to lift a weight, and "Carrying-Period" is the motion from lifting a weight to putting it on a platform The footswitch (Nor Switch, Noraxon USA) was attached to the bottom of a weight to observe the timing of these two motions. The motions of 10 times were identified by the foot switch signal and IEMG per motion was calculated with normalizing time. All IEMG values were normalized to theIEMG of lifting a weight to the level of 400f subject's height. In the Carrying-Period, the IEMG of rectusfemoris showed larger value than other muscles at the height of both 50-0x1.4aa00bfff764p-149nd 60%.0This suggests that therectus femoris plays an important role at these heights. In the Prepare-Period, the IEMG increased at eachheight. Especially, the IEMG of trapezius and rectus femoris at the height of 60howed larger valuecompared with biceps brachii and elector spinae. The reason is that subjects seem to have prepared at thePrepare-Period stage so as to make the trapezius and rectus femoris function effectively, muscles whichnaturally work well in the lifting motion at the "Carrying-Period". In short, Prepare-Period falls under theimportant introduction period for Carrying-Period and is regarded as an essential process of the lifting motion

The relation between standing balance and cognitive information processing performance in elderly persons. Examination by the dual-task assessment

先行研究によれば,バランス障害を有する高齢者は,立位保持と計算,数字の復唱などの認知課題とを同時に行った場合,バランス障害のない高齢者と比較して,有意に重心動揺が増加するとされている.本研究では,高齢者に,立位保持課題と認知課題(ストループテスト)を同時に行わせた場合と,それらを単一に処理した場合とで,立位保持課題と認知課題それぞれの処理能力にどのような変化がみられるのかを比較,検討した.対象は,65歳以上の高齢者であり,Berg Balance Scaleの得点により,彼らをバランス良好群(14名)とバランス不良群(9名)の2群に編成した.立位保持能力と認知課題処理能力の指標として,足圧中心変位の総軌跡長(Length: LNG)とストループテストの処理時間を用いた.バランス不良群では通常立位でのLNGとストループカラーテストを処理しながらのLNGの間に有意差が認められ,また,座位におけるストループカラーテストの処理時間と,立位におけるストループカラーテストの処理時間との間にも有意差が認められた.バランス良好群では,二重課題を行なってもLNGとストループテストの処理時間のどちらも影響を受けなかった.結果から,バランスの不良な高齢者は,立位保持と比較的複雑な認知課題を同時に行なうと,双方の処理能力が低下することが示唆され,これには,立位を保持するのに注意を必要とするかしないかが関係すると考えられた.Antecedent research indicates that elderly persons with a balance disorder have significantly moreshifts in their body center of gravity than those with no balance disorder, while they simultaneouslyperform a task to maintain a standing position and a cognitive task such as calculation and repetition ofnumbers. In this research, a comparative study was made to identify what differences can be observed withrespect to elderly persons' abilities to deal with a task to maintain a standing position and a cognitive taskrespectively, in the following two cases: (1) when an elderly person performs both a task to maintain astanding position and a cognitive task (based on a the Stroop Test) simultaneously, and (2) when theelderly person performs the above tasks individually. Subjects were elderly persons of 65 years old or overand were organized into two groups based on scores of the Berg Balance Scale: the first group wascomposed of those who had good balance (14 persons); and the second group, poor balance (9persons).As an index to measure the ability to maintain a standing position and to perform a cognitive task,total excursion length (Length: LNG) of the shift in the center of pressure and the performance time forthe Stroop Test were used. Among the group with poor balance, differences in LNG were recognizedsignificantly between the two cases: when the subjects were in an ordinary standing position, and when thesubjects were performing the Stroop Color Test. Significant differences were also found in theperformance time for the Stroop Color Test between the two cases: when the subjects were in a sittingposition and when the subjects were in a standing position. Among the group with good balance, neitherLNG nor performance time for the Stroop Test were affected by performing both tasks simultaneously.The findings suggest that when elderly persons with bad balance deal with a task to maintain a standingposition and a cognitive task with a relative complexity simultaneously, the performance ability for bothtasks decreased. Thus, it is considered that whether or not a person needs to pay attention to maintain astanding position is involved in the decreased performance ability

Features of the Dubowitz neurologic examination of preterm infants : Comparison with neonatal encephalopathy infants

低出生体重児57名と,新生児期に明らかな脳障害が確認された11名を対象に,出産予定日頃にDubowitz の神経学的評価を行った.発達に影響を及ぼす因子として報告されている,在胎週数,出生体重を考慮し,評価結果の比較検討を行った.評価したすべてのカテゴリーとtotal score において低出生体重児では早産・低体重の程度による影響を受けず,出産予定日での発達に差はなかった.tone,reflexes,behavior のカテゴリーでは早産児は脳障害児のスコアと比べて有意に高かった.また,tone patterns,abnormal signs では早産児と脳障害児でスコアに違いはみられず,このカテゴリーにおいて異常性との判別は難しいと考えられる.total score でみると早産児のスコアはDubowitz により報告されたカットオフ値の30 より低いスコアであり,低出生体重児での新たな基準を設定する必要が示唆された.Fifty-seven preterm infants and eleven infants in whom neonatal encephalopathy had been confirmed were examined by Dubowitz neurologic examination at term age. The results were compared based on their gestational age and birthweight, both of which are reported as factors which influence development. No influence of premature delivery and low weight was seen in preterm infants in the evaluated total score of the Dubowitz neurologic examination, and there was no difference in development at term age. There were significant differences in the scores in the categories of tone, reflexes, and behavior in the preterm infants compared with the neonatal encephalopathy infants. Moreover, no difference was seen in the score of the preterm infants and the neonatal encephalopathy infants in tone patterns and abnormal signs. Therefore, it is difficult to distinguish premature infants from abnormal infants in these categories. In this study, the total score reported by Dubowitz for preterm infants was lower than that for full-term infants, and the necessity for establishing a new standard for preterm infants is proposed

Mg 2+ regulates transcription of mgtA in Salmonella Typhimurium via translation of proline codons during synthesis of the MgtL peptide

International audienceIn Salmonella enterica serovar Typhimurium, Mg2+ limitation induces transcription of the mgtA Mg2+ transport gene, but the mechanism involved is unclear. The 5' leader of the mgtA mRNA contains a 17-codon, proline-rich ORF, mgtL, whose translation regulates the transcription of mgtA [Park S-Y et al. (2010) Cell 142:737-748]. Rapid translation of mgtL promotes formation of a secondary structure in the mgtA mRNA that permits termination of transcription by the Rho protein upstream of mgtA, whereas slow or incomplete translation of mgtL generates a different structure that blocks termination. We identified the following mutations that conferred high-level transcription of mgtA at high [Mg2+]: (i) a base-pair change that introduced an additional proline codon into mgtL, generating three consecutive proline codons; (ii) lesions in rpmA and rpmE, which encode ribosomal proteins L27 and L31, respectively; (iii) deletion of efp, which encodes elongation factor EF-P that assists the translation of proline codons; and (iv) a heat-sensitive mutation in trmD, whose product catalyzes the m1G37 methylation of tRNAPro Furthermore, substitution of three of the four proline codons in mgtL rendered mgtA uninducible. We hypothesize that the proline codons present an impediment to the translation of mgtL, which can be alleviated by high [Mg2+] exerted on component(s) of the translation machinery, such as EF-P, TrmD, or a ribosomal factor. Inadequate [Mg2+] precludes this alleviation, making mgtL translation inefficient and thereby permitting mgtA transcription. These findings are a significant step toward defining the target of Mg2+ in the regulation of mgtA transcription

Hypoxia increases gefitinib-resistant lung cancer stem cells through the activation of insulin-like growth factor 1 receptor.

Accumulating evidence indicates that a small population of cancer stem cells (CSCs) is involved in intrinsic resistance to cancer treatment. The hypoxic microenvironment is an important stem cell niche that promotes the persistence of CSCs in tumors. Our aim here was to elucidate the role of hypoxia and CSCs in the resistance to gefitinib in non-small cell lung cancer (NSCLC) with activating epidermal growth factor receptor (EGFR) mutation. NSCLC cell lines, PC9 and HCC827, which express the EGFR exon 19 deletion mutations, were exposed to high concentration of gefitinib under normoxic or hypoxic conditions. Seven days after gefitinib exposure, a small fraction of viable cells were detected, and these were referred to as "gefitinib-resistant persisters" (GRPs). CD133, Oct4, Sox2, Nanog, CXCR4, and ALDH1A1-all genes involved in stemness-were highly expressed in GRPs in PC9 and HCC827 cells, and PC9 GRPs exhibited a high potential for tumorigenicity in vivo. The expression of insulin-like growth factor 1 (IGF1) was also upregulated and IGF1 receptor (IGF1R) was activated on GRPs. Importantly, hypoxic exposure significantly increased sphere formation, reflecting the self-renewal capability, and the population of CD133- and Oct4-positive GRPs. Additionally, hypoxia upregulated IGF1 expression through hypoxia-inducible factor 1α (HIF1α), and markedly promoted the activation of IGF1R on GRPs. Knockdown of IGF1 expression significantly reduced phosphorylated IGF1R-expressing GRPs under hypoxic conditions. Finally, inhibition of HIF1α or IGF1R by specific inhibitors significantly decreased the population of CD133- and Oct4-positive GRPs, which were increased by hypoxia in PC9 and HCC827 cells. Collectively, these findings suggest that hypoxia increased the population of lung CSCs resistant to gefitinib in EGFR mutation-positive NSCLC by activating IGF1R. Targeting the IGF1R pathway may be a promising strategy for overcoming gefitinib resistance in EGFR mutation-positive NSCLC induced by lung CSCs and microenvironment factors such as tumor hypoxia

網膜症発現前の糖尿病患者における血液眼内柵透過性機能の解析

出版社版本研究では,網膜症初現前の糖尿病患者において,血液網膜柵(BRB)と血液房水柵(BAB)との透過性機能の関連を,fluorophotometryにより解析した.対象として網膜症を呈しない30歳から59歳までのインスリン非存型糖尿病患者51人96眼と,同一年齢群の正常者32人45眼を用いた.Fluorophotometryの測定結果を基にsimulatoin法によりBRBの透過性機能の指標として内方透過性係数(Pin)と後部硝子体内拡散係数(D-p)を推定し,一方BABにおける透過性機能の指標としては前房値および水晶後方の前部硝子体値を血漿中色素濃度で補正したAQおよびAV値を用いた.これら4つのparameterを検討した結果,40代および50代の糖尿病患者とは異なって30代の糖尿病患者でのみ同年代の正常群にくらべてAQおよびAV両値が有意に高く,一方,Pinには有意差を認めなかっ