渐进性抗阻训练对人体肌肉、骨骼、心脏功能的影响

通过实验性研究发现渐进性抗阻训练对人体骨、肌肉、心脏功能等有着重要影响。本文通过对相关文献的文献综述,发现渐进性抗阻训练可以起到显著增长肌肉力量和体积、增加骨密度及预防骨质疏松症等慢性病,改善心脏功能,提高血脂代谢水平,降低心血管疾病死亡率的作用。合理的安排抗阻训练计划,可以全面改善大学生骨骼肌肉的机能状况和健康水平,提高运动系统和心血管系统的能力。     

弹力带抗阻运动训练矫正肌力失衡性膝内翻康复研究

研究弹力带抗阻运动训练对矫正肌力失衡性膝内翻患者的疗效.以18例病程5-7年的男性患者为研究对象,通过弹力带抗阻运动训练疗法对患者腿部进行抗阻力量训练.经过5周运动训练康复期,患者膝关节屈曲位和髋关节内收位的肌肉力量均显著提高,各测量指标趋于正常,内侧髋收肌肌力大幅增加.对腿部肌力失衡所致的膝内翻患者,抗阻运动训练矫正效果明显.     

基于红外热图边界分割方法的康复机器人抗阻训练肌肉激活状态评估

红外热成像已被广泛用于显示人体热特性与肌肉激活之间的相关性.为探索红外热成像技术在上肢协调康复机器人抗阻训练模式下肌肉激活状态评估上的应用,采取调整上肢协调康复机器人抗阻方向和阻力等级,并通过采集红外图像来监测上臂3块目标肌肉(三角肌、肱二头肌和肱三头肌)区域的温度变化;同时,对不同训练状态下采集到的热图像进行分割且转换为彩色热图,并通过相对灰度值这一参数量化热图的温度变化.实验结果表明,所有训练状态下目标肌肉区域均被激活,且在不同阻力等级和不同阻力方向状态下不同肌肉区域的激活状态存在差异,证明红外热成像能够有效地评估上肢协调康复机器抗阻训练下目标肌肉区域的激活状态.     

抗阻康复训练对踝关节扭伤的影响研究

抗阻训练试验后踝关节的疼痛度和关节肿胀度都得到明显改善,抗阻训练实验后踝关节关节活动度和肌肉力量得到很大提高,Thera-Band渐进式抗阻训练系统说明对踝关节扭伤的康复效果疗效显著。     

不同时间的热处理对大鼠肌肉Akt/mTOR信号途径的影响

热处理会诱导骨骼肌中肌肉蛋白的合成及肌肉肥大,同时刺激细胞信号途径.另外,有报道表明38℃以上的热处理以温度依赖性方式激活细包内信号途径.然而,骨骼肌细胞中热刺激对信号途径的持续性影响方面鲜有报道.因此,分析了热处理对大鼠骨骼肌中信号途径的作用.利用Western blot技术检测热处理后不同时间点(30,60和90min)的腓肠肌及比目鱼肌中Akt/mTOR信号途径蛋白Akt,mTOR,p70S6K及4E-BP1的磷酸化水平及热激蛋白HSP72的表达水平.结果表明,Akt及mTOR的磷酸化水平没有变化,磷酸化的p70S6K及4E-BP1水平有所上调,而热激蛋白HSP72的水平有所下调.     

七鳃鳗CD63的分子克隆、生物学特性及表达分析

从日本七鳃鳗和东北七鳃鳗中克隆得到了CD63基因的ORF区,预测了其编码的氨基酸序列.利用生物信息学方法进行了氨基酸序列分析并构建了进化树.实时定量PCR技术分析表明:CD63在日本七鳃鳗的心脏、肝脏、肌肉、髓、鳃、肠和卵中均有表达.其中,在卵中的表达量最高.脂多糖(LPS)体内刺激日本七鳃鳗后发现,CD63在肝脏和肌肉中的表达显著升高.本研究为进一步了解CD63分子在七鳃鳗的免疫方面的作用提供了实验依据.     

抗阻力训练的运动学特征

当前针对各种抗阻力训练对肌肉力量和爆发力的影响,人们进行了大量研究,但对其诱导的机械刺激与肌体适应方面的认识,仍存在严重不足。目前认为,抗阻力训练动力学的变化(力量、收缩持续时间和爆发力等)以及这些变化诱导机体内激素及代谢物的改变,可以影响肌肉力量的获得和爆发力的发展;而对于不同运动学变量之间结合的效果,及其对肌肉适应产生的影响并不清楚。认识机械刺激与肌体适应之间的关系,有助于更科学地把力量训练和爆发力训练结合在一起,提高训练效益。     

力生长因子与成骨细胞

骨组织对所处的力学环境有极强的适应能力.力学因素及非力学因素共同参与调节骨组织的生长、发育与适应性变化,但是关于两者之间的关联调控目前知之甚少.在骨骼肌肉系统中,IGF-I是一种与力刺激密切相关的骨生长因子.在力刺激作用下,IGF-I的pre-mRNA能选择性的剪接成为力生长因子（Mechano-growth factor,MGF）,MGF具有促进成肌干细胞和成骨细胞增殖,并抑制其终末分化的作用.在力刺激下,MGF参与骨骼肌肉的重建和修复过程.目前初步研究显示MGF主要分布在细胞核,其信号传导不通过IGF-IR介导.但关于MGF的细胞受体,作用靶点、作用机制和信号传导还未得到有效阐明;本文就MGF与骨骼的力学调控之间的关系进行综述.     

长期游泳训练后小鼠肝脏和骨骼肌游离氨基酸的变化及其机理的探讨

本文观察了小鼠45天游泳训练后恢复期肝脏和骨骼肌游离氨基酸的变化。结果表明:训练组小鼠股四头肌大多数氨基酸明显升高,而肝脏大多数氨基酸出现降低,其中肌肉支链氨基酸的增多和肝脏支链氨基酸的减少十分显著;血尿素氮也有意义的降低。提示:长期训练的恢复期内,游离氨基酸的流向主要趋于肝脏向骨骼肌输出,以促进肌肉蛋白质尽快合成,肝脏氨基酸的恢复似乎滞后于肌肉。耐力训练中及恢复期体内激素水平的变化是调控氨基酸代谢的主要因素和可能机制。     

有氧间歇训练对心肌梗死大鼠心肌细胞的增殖作用及相关机制

目的:通过建立SD大鼠心肌梗死模型,观察间歇训练对心梗大鼠心肌细胞的增殖作用并探讨其内在作用机制.方法:成年雄性SD大鼠40只,造模后,随机分为3组:假心梗组(CON);心梗组(MI);心梗+间歇训练组(MI+AIT),每组12只.间歇训练共计8周.结果:免疫组化结果提示,正常心肌组织鲜见细胞增殖现象;心肌梗死可造成梗死边缘区细胞代偿性增加;间歇训练可显著性增加细胞增殖核抗原PCNA,BrdU和ki-67的表达水平.另外,心梗还可引起细胞增殖核抗原调节蛋白p70S6K及其上游调节蛋白mTOR显著性降低(P<0.05);而mTOR的上游调节蛋白PI3K,Akt也具有相似的变化趋势.相对地,间歇训练可增加心肌细胞膜IGF-R1水平(非IGF-R2),上调PI3K-AKt-mTOR信号通路活性,增加p70S6K磷酸化水平(P<0.05).结论:间歇训练介导的细胞增殖作用与其上调IGF-R1表达水平,激活细胞PI3K-Akt介导的增殖通路相关.     

New insights into mTOR structure and regulation

The mammalian target of rapamycin, mTOR, forms various protein-protein complexes to regulate cell growth in response to the nutrient and energy status of the cell. Recently, the first crystal structure of large HEAT repeat protein mTOR revealed that the FAT domain interacts with the kinase domain through electrostatic effects and hydrophobic interactions. Based on the structure, the previous researches on how FAT domain regulates mTOR activity are reviewed. DEPTOR is currently known as an endogenous mTOR inhibitor, which may interact with roTOR FAT domain to suppress mTOR activity in vivo. The possible interactions of DEPTOR with the mTOR FAT domain are analyzed, too. In addition, the inhibition mechanism of DEPTOR may be similar to members of HEAT-involved RanGTP complex family, providing new mechanistic insights into mTOR kinase regulation.     

藏鸡肌肉生长抑制素基因克隆及序列分析

肌肉生长抑制素基因是骨骼肌发育的负性调控因子,本研究利用RT-PCR及T-A克隆技术得到藏鸡myostation编码基因,DNA长1128bp,编码375个氨基酸．本研究克隆的藏鸡MSTN基因,在动物育种、畜牧生产以及治疗肌肉消耗疾病方面具有潜在的应用价值．     

Survival signalling by Akt and eIF4E in oncogenesis and cancer therapy

Evading apoptosis is considered to be a hallmark of cancer, because mutations in apoptotic regulators invariably accompany tumorigenesis. Many chemotherapeutic agents induce apoptosis, and so disruption of apoptosis during tumour evolution can promote drug resistance. For example, Akt is an apoptotic regulator that is activated in many cancers and may promote drug resistance in vitro. Nevertheless, how Akt disables apoptosis and its contribution to clinical drug resistance are unclear. Using a murine lymphoma model, we show that Akt promotes tumorigenesis and drug resistance by disrupting apoptosis, and that disruption of Akt signalling using the mTOR inhibitor rapamycin reverses chemoresistance in lymphomas expressing Akt, but not in those with other apoptotic defects. eIF4E, a translational regulator that acts downstream of Akt and mTOR, recapitulates Akt's action in tumorigenesis and drug resistance, but is unable to confer sensitivity to rapamycin and chemotherapy. These results establish Akt signalling through mTOR and eIF4E as an important mechanism of oncogenesis and drug resistance in vivo, and reveal how targeting apoptotic programmes can restore drug sensitivity in a genotype-dependent manner.     

Differential expression analysis and regulatory network reconstruction for genes associated with muscle growth and adipose deposition in obese and lean pigs

During the growth and development of skeletal muscle cells and adipose cells, the regulatory mechanism of micro-effect polygenes determines porcine meat quality, carcass characteristics and other relative quantitative traits. Obese and lean type pig breeds show obvious differences in muscle growth and adipose deposition; however, the molecular mechanism underlying this phenotypic variation remains unknown. We used pathway-focused oligo microarray studies to examine the expression changes of 140 genes associated with muscle growth and adipose deposition in longissimus dorsi muscle at six growth stages （birth, 1, 2, 3, 4 and 5 months） of Landrace （a leaner, Western breed） and Taihu pigs （a fatty, indigenous, Chinese breed）. Variance analysis （ANOVA） revealed that differences in the expression of 18 genes in Landrace pigs and three genes in Taihu pigs were very significant （FDR-adjusted permutation, P 〈 0.01） and differences for 22 genes in Landrace pigs and seven genes in Taihu pigs were significant （FDR-adjusted permutation, P 〈 0.05） among six growth stages. Clustering analysis revealed a high level of significance （FDR-adjusted, P 〈 0.01） for four gene expression patterns, in which genes that strongly up-regulated were mainly associated with the positive regulation of myofiber formation and fatty acid biogenesis and genes that strongly down-regulated were mainly associated with the inhibition of cell proliferation and positive regulation of fatty acid β-oxidation. Based on a dynamic Bayesian network （DBN） model, gene regulatory networks （GRNs） were reconstructed from time-series data for each pig breed. These two GRNs initially revealed the distinct differences in physiological and biochemical aspects of muscle growth and adipose deposition between the two pig breeds; from these results, some potential key genes could be identified. Quantitative real-time RT-PCR （QRT-PCR） was used to verify the microarray data for five modulated genes, and a good correlation between     

诱惑与困惑——抗阻练习与青年女性身体健康研究

运用文献资料调研和逻辑分析等研究方法,探讨抗阻练习对青年女性肌肉与骨骼的积极影响和中国青年女性参与较少的原因。结果表明：抗阻练习能有效提高青年女性肌肉力量并有利于她们保持骨健康。中国青年女性较少参与主要是担忧练习会使身体变得“强壮”。而多进行多关节练习并常变换练习方法和运动负荷能显著减少肌肉肥大。这对消除青年女性的参与困惑,吸引她们积极参与有助于保持机体健康抗阻练习具有重要作用。     

A keratin cytoskeletal protein regulates protein synthesis and epithelial cell growth

Cell growth, an increase in mass and size, is a highly regulated cellular event. The Akt/mTOR (mammalian target of rapamycin) signalling pathway has a central role in the control of protein synthesis and thus the growth of cells, tissues and organisms. A striking example of a physiological context requiring rapid cell growth is tissue repair in response to injury. Here we show that keratin 17, an intermediate filament protein rapidly induced in wounded stratified epithelia, regulates cell growth through binding to the adaptor protein 14-3-3sigma. Mouse skin keratinocytes lacking keratin 17 (ref. 4) show depressed protein translation and are of smaller size, correlating with decreased Akt/mTOR signalling activity. Other signalling kinases have normal activity, pointing to the specificity of this defect. Two amino acid residues located in the amino-terminal head domain of keratin 17 are required for the serum-dependent relocalization of 14-3-3sigma from the nucleus to the cytoplasm, and for the concomitant stimulation of mTOR activity and cell growth. These findings reveal a new and unexpected role for the intermediate filament cytoskeleton in influencing cell growth and size by regulating protein synthesis.     

肌肉疲劳及肌肉损伤机理自由基学说研究综述

随着竞技体育的飞速发展,许多运动员在训练和比赛中承受的负荷越来越大,时间越来越长,由肌肉收缩所导致的肌肉损伤呈现逐渐增加的趋势,直接影响运动员正常的训练和比赛,制约了运动技能的维持和发展,严重者会导致运动生涯的缩短。目前运动负荷所致肌肉损伤的确切机理尚不十分清楚。据此,本研究通过自由基和脂质过氧化反应及调节损伤修复的生长因子层面,系统分析和探讨了肌肉疲劳及肌肉损伤和损伤产生的机制,以期为运动训练提供一些理论参考。