5000米跑耐力训练对新兵有氧耐力及左心室结构和功能的影响

目的:严格控制实验条件,观察18周5000米长跑耐力训练效果,为基因多态与训练效果的关联性分析提供基础数据。方法:102名中国汉族士兵每周训练3次,采用前10周95%VTHR(通气无氧阈时的心率)±3和后8周105%VTHR±3来控制跑速。用体成分测定仪测定18周训练前后受试者的体成分,通过递增负荷跑台运动,分别于训练前后测定VO2max(最大摄氧量)、VT(通气无氧阈)、RE(跑节省化)实验中相关有氧耐力指标,通过定量负荷蹬车运动测定训练前后左心室结构与功能相关指标。结果:18周训练后受试者VO2max较训练前平均增加了1·56%(P<0·01),VT时摄氧量提高了2·59%(P<0·05),RE时的摄氧量较训练前下降7·60%~9·43%(P<0·01);训练后左心室每搏量增加、心输出量节省化和左室重量增加。结论:5000跑耐力训练可明显提高受试者有氧耐力水平,递增负荷下左心室结构与功能呈现良好的顺应性变化。     

肌红蛋白基因多态与有氧训练效果的关联性分析

目的:探讨肌红蛋白第2外显子的单核苷酸多态(A79G)与有氧耐力训练效果的关联性。方法:对中国北方新征入伍的104名汉族士兵进行每次5000米、每周3次、训练强度为95～105%通气无氧阈(VT)、为期20周的耐力训练。递增负荷运动实验测定受试对象训练前后最大摄氧量(VO2max)和通气无氧阈(VT),PCR-RFLP法测定基因多态性,分析基因多态性与训练效果之间的关联性。结果:3种基因型的分布频率分别为AA(0.52)、AG(0.45)、GG(0.03),分布频率符合Hardy-weinberg遗传平衡定律;训练后3种基因型VO2max的组间比较均无显著性差异(P>0.05);训练后GG组和AG组VT显著提高(P<0.05),AA组达到VT时仅HR显著升高,其余指标均无显著变化(P>0.05)。在VO2max和VT的变化率(Δ%)方面,GG组受试者提高最多,AG组居中,AA组提高最少。提示肌红蛋白基因第2外显子的单核苷酸多态(A79G)与有氧耐力训练效果有一定关联,79G等位基因携带者对有氧耐力训练可能更敏感。     

运动训练与最大心率

心率是运动生理学中最常用又简单易测的一项指标.在体育实践中,最大心率首先是用于确定运动强度.无论是体疗康复还是健身锻炼、运动训练,都需要确定运动强度.运动强度通常是用心率来控制的,一般是直接用最大心率(HRmax)百分比确定[1],或者结合安静时心率(HRrest)和心率储备(HRR:heart rate reserve,即最大心率和安静心率之差)推算.Karvonen认为,用持续训练法发展有氧耐力时应当选用的心率为:安静心率 (最高心率-安静心率)×60%[2].美国运动医学会(American College of Sports Medicine, ACSM)建议制定运动处方确定运动强度时采用最大心率百分比,但这与Swain DP等人的研究结果有差异[3].其次,最大心率还用于推算最大吸氧量.Niels Uth等用最大心率与安静心率的比值(HRmax/HRrest)乘15.26ml*min-1*kg-1推算运动员的单位体重的最大吸氧量,并通过数学推理和实验验证,认为这是一种简单估算最大吸氧量的方法[4].此外,最大心率还可用于确定运动终点.临床上,运动试验必须在受试者的心率达到最大心率的一定比例时(如85%HRmax)停止[5].在确定最大有氧工作能力时,最大心率还用于判断受试者是否尽了全力[6,7].研究最大心率及其影响因素在运动实践中具有重要意义,本文就最大心率的推算、运动训练对最大心率的影响的研究作一综述.     

Kir6.2基因E23K位点多态性与耐力训练后血糖、胰岛素和VO2max改变的关系

目的探讨Kir6.2基因E23K位点多态性与耐力训练所致的血糖、胰岛素和VO2max改变间的关系.方法采用PCR-RFLP技术对214例美国各种族50至75岁男女受试者的Kir6.2位点E23K多态性进行基因型分析.受试者在专人监控下进行24周的耐力训练后,观察其E23K与血糖、胰岛素和VO2max之间的关系.结果(1)三种基因型受试者的空腹血糖、胰岛素和VO2max的基础值无显著差异;(2)24周耐力训练后,三种基因型受试者的VO2max均显著升高(P＜0.05),体重和体脂则显著下降(P＜0.05),身高体重指数(BMI)和呼吸商(RER)则在男性各基因型中显著下降(P＜0.05);(3)24周耐力训练后,三种基因型受试者的空腹胰岛素水平和曲线下面积(AUC)均显著下降(P＜0.05),但训练并未引起空腹血糖及其AUC显著变化.(4)男性EK基因型RER显著低于EE和KK基因型,女性则表现为KK基因型显著高于EE基因型.结论(1)无论E23K位点的基因型为EE、EK或KK,24周的耐力训练均可提高受试者的VO2max并降低体重、体脂、空腹胰岛素水平和AUC;(2)耐力训练对男性BMI和RER降低的影响更显著;(3)E23K多态性与RER的关系较VO2max和血糖水平更密切.     

跑节省化评价有氧耐力及其训练效果实验研究

目的:探讨跑节省化(RE)指标在表达耐力能力方面的重要程度与应用价值。方法:102名新兵进行18周5000米长跑训练,每周训练3次,以95%和105%个体通气无氧阈(VT)时的心率作为强度控制标准,以Polar心率表作为控制手段。测定其训练前后的VO2max、VT和RE及其相关指标,并运用主成分分析方法对表达有氧能力初始水平和训练效果的不同指标进行重要程度的分析。结果:18周耐力训练使VO2max增加了1.56%,VT-VO2提高了2.59%,而RE各值均显著下降(范围为7.68%～9.43%,P<0.01)。在表达耐力初始水平方面,RE各指标的贡献率较大;在表达耐力训练效果方面,VO2max与RE各指标的贡献率和因子载荷较大。结论:RE在评价普通人群(即训练初期)的耐力及其耐力训练效果方面优于VO2max和VT指标。     

PPARδ基因多态与有氧能力及训练敏感性的关联研究

目的探讨过氧化物酶体增殖物激活受体δ(PPARδ)基因第四外显子的单核苷酸多态(C294T)是否与有氧运动能力及训练敏感性相关联。方法对102名中国北方地区汉族男性青年进行为期18周的耐力训练(每次5000米、每周3次)。强度以个体通气无氧阈(VT)对应的心率(HRVT)为标准,前10周采用95%通气无氧阈对应的心率(HRVT±3),后8周采用105%通气无氧阈对应的心率(HRVT±3)。递增负荷运动实验测定受试者训练前后VO2max及相关指标和跑节省化时的心率(HR)、通气量(VE)和摄氧量(VO2)。采用限制性片断长度多态(PCR-RFLP)法测定PPARδ基因C294T位点。结果三种基因型的分布频率分别为CC基因型9人(0.09)、CT基因型37人(0.36)和TT基因型56人(0.55),符合Hardy-Weinberg平衡。按基因型分组后,CC基因型训练前的VO2max相对值显著性高于CT基因型和TT基因型(P<0.05);携带不同基因型群体的VO2max、跑节省化测试中的各项指标的变化率无显著性差异(P>0.05)。结论PPARδ基因第四外显子的单核苷酸C294T多态与VO2max相对值的初始值相关联,但与有氧耐力训练效果不关联。     

清华大学跳水队优秀运动员有氧代谢能力测试分析

目的:测试分析有潜力的学生跳水运动员的有氧代谢能力。方法:清华大学跳水队优秀跳水运动员9名,年龄13~15岁,采用递增负荷试验,运用心肺功能测试系统对运动员有氧能力进行测试与分析,测试过程中监测心率和心电图。结果:男运动员VO2max和VO2max/kg显著高于女运动员(P<0.01),男运动员无氧阈时的VO2和VO2/kg、%VO2max、HR、氧脉搏也显著高于女运动员(P<0.01)。结果提示:男运动员有氧能力显著优于女运动员,男子运动员所能承受的运动负荷与潜能大于女子,表明在13~15岁这个年龄阶段的优秀学生跳水运动员的有氧代谢能力存在性别差异,但整体水平还较弱,故训练中应给予重视,以保证长时间、大强度高难度动作的重复训练和比赛中技术水平的稳定发挥。     

瘦素受体基因多态性与有氧耐力及其训练效果的关联性研究

目的:探讨瘦素受体(OB-R)基因第6外显子Gln223Arg多态性与有氧耐力及有氧耐力训练效果的关联性。方法:对新征入伍的102名中国北方汉族士兵进行为期18周、每周3次、每次5000米、强度为95~105%通气阈(VT)的耐力训练。采用跑台逐级递增负荷运动实验测定受试者训练前后最大摄氧量(VO2max),并在12km/h跑速时测定跑节省化(RE)时的心率(HR)、通气量(VE)和摄氧量(VO2);利用限制性片断长度多态(PCR-RFLP)法进行OB-R基因Gln223Arg多态性解析。结果:(1)OB-R基因Gln223Arg多态性在中国北方汉族人群中的分布频率分别为AA:3%、AG:25%、GG:72%,符合Hardy-Weinberg遗传平衡定律;(2)按基因型分组后,A等位基因携带者(AA+AG)训练前的最大摄氧量相对值明显高于未携带者(GG),其他指标训练前后在两组之间无显著性差异。结论:OB-R基因第6外显子的Gln223Arg多态性与有氧能力可能存在关联,而与有氧耐力训练效果不关联。     

耐力训练对青少年运动员最大摄氧量和动脉血酮体比的影响

目的:观察耐力训练对青少年运动员有氧能力和动脉血酮体比(AKBR)的影响。方法:18名青少年游泳运动员4周耐力训练前后,测定其递增负荷运动实验中VO2max、血乳酸和心率变化,以及恒定负荷运动实验后酮体含量和动脉血酮体比。结果:4周耐力训练后,受试者VO2max、最大运动时的负荷、心率、血乳酸水平较训练前显著提高,个体乳酸阈呈升高趋势;递增负荷运动中的摄氧量、心率和血乳酸动力学曲线右移;动脉血酮体比显著提高。结果表明,伴随青少年游泳运动员有氧运动能力的改善,在等量负荷运动条件下其肝线粒体氧化还原状态和能荷增强。     

中国北方汉族男性SHBG基因启动子(TAAAA)n多态分布及其与有氧能力的关联性研究

目的:探讨性激素结合球蛋白(SHBG)基因(TAAAA)n多态在中国北方汉族男性中的分布特征及其与有氧能力的关联性。方法:102名中国北方汉族健康青年男性受试者进行为期20周、每周3次5000米匀速跑的有氧耐力训练,训练前后分别测试VO2max和RE相关生理指标。使用GeneScan和测序方法分析SHBG(TAAAA)n多态等位基因和基因型。进行该多态与有氧能力初始值和耐力训练效果的关联性分析。结果:(1)在中国北方汉族男性中观察到(TAAAA)6～10次重复等位基因和11个基因型。其中,9次重复等位基因分布频率最高,10次重复等位基因分布频率最低;(2)当分别以7、8和9次重复作为分割点划分基因型时,发现长链组VO2max相关指标训练前初始水平平均值均大于短链组。其中,按7次重复划分时,≥7次基因型携带者训练前VO2max和VO2max时的VE初始值均有高于<7次携带者的趋势(P均为0.06);(3)不同基因型组间VO2max和RE各指标的耐力训练敏感性无显著性差异。结论:SHBG基因(TAAAA)n多态与男性有氧能力指标初始水平可能存在一定的关联性,推测重复次数较多的等位基因携带者的有氧能力初始水平较好,但与耐力训练敏感性无关联。     

Knee injury and Osteoarthritis Outcome Score (KOOS) - validation of a Swedish version

The Knee injury and Osteoarthritis Outcome Score (KOOS) is a self-administered instrument measuring outcome after knee injury at impairment, disability, and handicap level in five subscales. Reliability, validity, and responsiveness of a Swedish version was assessed in 142 patients who underwent arthroscopy because of injury to the menisci, anterior cruciate ligament, or cartilage of the knee. The clinimetric properties were found to be good and comparable to the American version of the KOOS. Comparison to the Short Form-36 and the Lysholm knee scoring scale revealed expected correlations and construct validity. Item by item, symptoms and functional limitations were compared between diagnostic groups. High responsiveness was found three months after arthroscopic partial meniscectomy for all subscales but Activities of Daily Living.     

Endovascular management of carotid-cavernous fistulas

Objective To investigate endovascular treatment of traumatic direct carotid-cavernous fistulas （CCF） and their complications such as pseudoaneurysms. Methods： Over a five-year period, 22 patients with traumatic direct CCFs were treated endovascularly in our institution. Thirteen patients were treated once with the result of CCF occluded, 8 twice and 1 three times. Treatment modalities included balloon occlusion of the CCF, sacrifice of the ipsilateral internal carotid artery with detachable balloon, coll embolization of the cavernous sinus and secondary pseudoaneurysms, and covered-stem management of the pseudoaneurysms. Results All the direct CCFs were successfully managed endovascularly. Four patients developed a pseudoaneurysm after the occlusion of the CCF with an incidence of pseudoaneurysm formation of 18.2% （4/22）. A total number of 8 patients experienced permanent occlusion of the ICA with a rate of ICA occlusion reaching 36.4% （8/22）. Followed up through telephone consultation from 6 months to 5 years, all did well with no recurrence of CCF symptoms and signs. Conclusion Traumatic direct CCFs can be successfully managed with endovascular means. The pseudoaneurysms secondary to the occlusion of the CCFs can be occluded with stent-assisted coiling and implantation of covered stents.     

The acutely limping child

Acute limping may be the result of multiple pathologies in children. The differential diagnosis varies based on the age of the child. Irrespective of age, the initial imaging work-up includes AP and frog leg radiographs of the pelvis and ultrasound; MRI may sometimes be helpful. In children less than 3 years, infections and trauma are most frequent. MRI is the imaging modality of choice when osteomyelitis is clinically suspected. Between the ages of 3 and 10 years, transient synovitis of the hip and Legg-Calvé-Perthes disease are main considerations but infection, inflammation and focal bony lesions are also considered. In children over 10 years, slipped capital femoral epiphysis also is considered.     

Do Balance Board Training Programs Reduce the Risk of Ankle Sprains in Athletes?

Introduction Ankle sprains are the most common musculo-skeletal injury that occurs in athletes,particularly in sports that require jumping and landing on one foot such as soccer,and basketball(1-4).These injuries often result in significant time loss from participation,long-term disability,and have a major impact on health care costs and resources(5-8).     

High Intensity Interval Training:New Insights

KEY POINTS ·High-intensity interval training(HIT)is characterized by repeated sessions of relatively brief，intermittent exercise.often performed with an“a11 out”effort or at an intensity close to that which elicits peak oxygen uptake(i.e.，≥90%of VO2 peak).     

Developmental validation of the PowerPlex(®) ESI 16 and PowerPlex(®) ESI 17 Systems: STR multiplexes for the new European standard

In response to the ENFSI and EDNAP groups’ call for new STR multiplexes for Europe, Promega^® developed a suite of four new DNA profiling kits. This paper describes the developmental validation study performed on the PowerPlex^® ESI 16 (European Standard Investigator 16) and the PowerPlex^® ESI 17 Systems. The PowerPlex^® ESI 16 System combines the 11 loci compatible with the UK National DNA Database^®, contained within the AmpFlSTR^® SGM Plus^® PCR Amplification Kit, with five additional loci: D2S441, D10S1248, D22S1045, D1S1656 and D12S391. The multiplex was designed to reduce the amplicon size of the loci found in the AmpFlSTR^® SGM Plus^® kit. This design facilitates increased robustness and amplification success for the loci used in the national DNA databases created in many countries, when analyzing degraded DNA samples. The PowerPlex^® ESI 17 System amplifies the same loci as the PowerPlex^® ESI 16 System, but with the addition of a primer pair for the SE33 locus. Tests were designed to address the developmental validation guidelines issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM), and those of the DNA Advisory Board (DAB). Samples processed include DNA mixtures, PCR reactions spiked with inhibitors, a sensitivity series, and 306 United Kingdom donor samples to determine concordance with data generated with the AmpFlSTR^® SGM Plus^® kit. Allele frequencies from 242 white Caucasian samples collected in the United Kingdom are also presented. The PowerPlex^® ESI 16 and ESI 17 Systems are robust and sensitive tools, suitable for the analysis of forensic DNA samples. Full profiles were routinely observed with 62.5 pg of a fully heterozygous single source DNA template. This high level of sensitivity was found to impact on mixture analyses, where 54–86% of unique minor contributor alleles were routinely observed in a 1:19 mixture ratio. Improved sensitivity combined with the robustness afforded by smaller amplicons has substantially improved the quantity of data obtained from degraded samples, and the improved chemistry confers exceptional tolerance to high levels of laboratory prepared inhibitors.