中长跑运动员胃肠菌群区系结构分布特征的微生态研究

目的:应用分子生物学的实验方法和技术研究中长跑运动员胃肠菌群区系结构分布特征.方法:直接从运动员粪便样品中提取细菌总DNA,并以此为模板进行PCR扩增,得到不同运动个体胃肠细菌基因指纹图;然后将1名运动员的PCR产物用地高辛标记为探针,与其余6名运动个体的胃肠细菌指纹图进行核酸印迹杂交;最后对目的基因片段进行克隆和测序.结果:(1)不同运动个体胃肠菌群中既存在共有菌群,又存在个体特征菌群;(2)普遍存在于运动员胃肠道中的某种特征菌群,在基因库中无与其同源的序列,可能是一种尚未被报道的新型菌群.     

DNA指纹图谱在炎症性肠病肠道菌群分析中的价值

目的利用DNA指纹图谱分析肠道菌群变化与炎症性肠病的关系。方法研究对象分为正常组和病例组,每组各6例,分离结肠黏膜组织,提取黏膜细菌组DNA,应用细菌16 S rDNA的PCR-单链构象多态性(PCR-SSCP)技术对肠道菌落进行初步鉴定,并对其组成结构进行分析,留取部分远端结肠进行菌群定植数量分析。结果病例组和正常组的所有样本分别进行3次以上的PCR-SSCP指纹图谱分析,得到了稳定可重复的图谱。病例组同正常组比较,菌群多样性明显减少。肠球菌和肠杆菌数量增多(P<0.05),乳酸杆菌和双歧杆菌数量明显减少(P<0.05)。两组比较主要是不可培养细菌的差异。结论炎症性肠病患者肠道菌群菌属多样性减少,各肠道菌属间存在比例失调,肠道微生态失调可能参与炎症性肠病的产生或加重过程。     

几种肠道疾病患者肠道菌群结构特征的DNA指纹图谱分析

目的 建立肠道疾病患者肠道细菌的DNA指纹图谱,并分析其肠道菌群结构特征的整体差异.方法选取消化科37例经结肠镜确诊的肠道疾病患者,包括溃疡性结肠炎(UC)患者20例、肠易激综合征(IBS)患者6例、急性胃肠炎患者11例,另取11名健康成人作为正常对照.提取粪便标本细菌总DNA,应用肠杆菌基因间重复共有序列基因扩增技术(ERIC-PCR)建立肠道菌群的DNA指纹图谱并分析其整体差异.结果 UC患者样本DNA条带明显少于其他肠道疾病患者和正常对照,提示UC、急性胃肠炎、IBS和正常对照的肠道菌群存在整体差异.17例UC患者标本DNA主带出现在0.7kb处,11例急性胃肠炎患者样本在0.8kb和1.1kb处显示2条DNA主带,而正常对照和IBS患者样本DNA主带均无统一趋势.结论 UC可能存在较单一的肠道优势菌群,其发病机制可能与特定的肠道细菌感染有关.     

运动与肠道菌群相关研究的热点主题和趋势——基于文献计量学分析

目的：梳理运动与肠道菌群的相关研究,明晰其发展脉络及动态,为后续相关研究提供参考。方法：基于CiteSpace可视化软件,对Web of Science Core Collection(WoS核心合集)数据库收录的522篇文献进行分析,梳理出运动与肠道菌群相关研究领域的热点主题、研究趋势。主要结果：研究热点紧密围绕运动、肠道菌群、疾病、营养与饮食、益生菌展开,具体热点主题包括：运动与疾病人群肠道菌群关系的研究;剧烈运动与运动员胃肠道症状关系的研究;运动、饮食、营养及益生菌关系的研究。研究趋势主要有：干预方案和健康获益之间的剂量效应特征的挖掘;运动对肠道菌群作用机制的探索;疾病类型以及疗效指标的转变。     

以肠道菌群为靶点的代谢综合征运动干预研究进展

代谢综合征已成为威胁全球的公共健康问题。大量实验证明,肠道菌群可通过调节宿主脂肪吸收存储相关基因影响宿主能量平衡,肠道菌群结构失调会导致宿主血液内毒素增加,诱发慢性低度炎症,致使胰岛素抵抗;适宜运动可有效干预肠道菌群结构和功能,帮助机体建立健康菌群。运用元基因组学、微生物分子生态学和代谢组学方法,揭示与代谢综合征相关的肠道菌群结构失调,鉴定出代谢综合征相关的特定细菌类群及功能,使得通过以肠道菌群为靶点的运动干预防治代谢综合征成为可能。     

酸枣仁与其混淆品及伪品的RAPD分析

目的 对酸枣仁及其混淆品和伪品进行DNA指纹图谱的鉴别研究,并对分子生物学在中药材鉴别中存在的一些问题进行探讨。方法 应用随机扩增DNA多态性技术对酸枣仁及其易混淆品、伪品进行DNA指纹图谱多态性的比较。结果 DNA指纹图谱显示,各样品间具有不同的遗传关系,根据这些差别成功地进行了酸枣仁及其易混淆品、伪品的鉴别。结论 RAPD可以有效地鉴别酸枣仁与其混淆品及伪品。同时对RAPD中存在的问题进行了讨论。     

肝硬化患者肠道微生物代谢功能的宏基因组学研究

目的：分析肝硬化患者远端肠道微生态菌群代谢功能的变化。方法选取16例肝硬化患者及20例正常人,提取其肠道微生物宏基因组DNA进行高通量Solexa测序,对测序基因进行代谢功能的注释,比较肝硬化患者与正常人之间的差异,找出疾病相关的肠道微生物代谢功能的变化。结果肝硬化患者肠道菌群功能多样性降低,对药物、必需氨基酸、丙酸盐等的代谢能力以及炎性反应显著增强,而对丁酸盐、胆汁酸的代谢能力以及细胞周期相关的功能显著降低。结论在肝硬化的影响下,肠道微生物的生长环境被破坏,肠道菌群为了适应环境,在功能和代谢方面表现出一定程度的代偿。     

地黄寡糖灌胃对糖尿病大鼠的降糖作用及对肠道菌群的影响

目的 :观察地黄寡糖灌胃给药对四氧嘧啶 (ALX)糖尿病大鼠的降糖作用和对肠道菌群的影响。方法 :以AL× (1 50mg·kg- 1 ,ip)诱发糖尿病大鼠模型 ,灌胃给予地黄寡糖 2 0 0mg·kg- 1 ·d- 1 ,检测给药前、给药 7d及给药 1 4d后大鼠血糖、血浆胰岛素、肝糖原的变化及给药 1 4d肠道菌群的变化。结果 :给药组大鼠血糖降低、血清胰岛素浓度及肝糖原含量增加 ,肠道菌群中双歧杆菌类杆菌、乳杆菌等优势菌群的数量明显增加 ,与糖尿病模型组比较差异有显著性 (P <0 .0 5)。结论 :地黄寡糖具有降低ALX糖尿病大鼠血糖及调节肠道菌群功能的作用 ,调节机体微生态平衡可能是地黄寡糖降血糖机制之一。     

微血管反应性在耐力性运动员训练中的应用

研究认为:微血管反应性与耐力性运动员运动性疲劳的产生、身体机能状态的变化有着密切关系,可作为运动员身体机能状态监控的无创性指标,但在高原训练阶段相关研究的结论尚不明确,这与高原上特殊的缺氧、干燥自然环境、海拔高度以及运动负荷等对运动员微血管反应性的复杂影响有关;微血管反应性应用于运动负荷、专项能力变化的评定可能是评价训练科学性和效果的新手段,但相关研究存在项目单一、特殊训练手段下研究结果不明确等问题,尤其高原训练阶段,研究人员需要从不同运动项目、不同训练手段和阶段等方面对微血管反应性在耐力性运动员中的应用进行定量研究。     

不同减肥方式对肠道菌群影响的研究进展

单纯性肥胖所致个体罹患心脑血管疾病、糖尿病及肿瘤的几率大大增加。目前有大量研究证实:肠道菌群组成成分与结构失衡是导致肥胖发生的重要诱因,但减肥过程中肠道菌群及其代谢产物的变化趋势及相关机制研究尚缺乏报道。本文就目前应用较广的补充功能食品减肥、有氧运动减肥、外科手术减肥对肠道菌群及其代谢产物变化的影响进行综述。     

青少年中长跑运动员次最大强度负荷的心肺功能动态观察

<正> 研究中长跑运动对正处于生长发育期的青少年心肺功能的影响,显然具有特殊意义。但目前有关专题报道却并不多,特别是综合的动力学实验性研究文献就更为少见。为此,我们对中长跑青少年专项运动员进行了次最大强度负荷的动态观察,并与非运动员作对照。鉴于现有文献报道多为男性资料,故本工作对女性亦予关心。     

Stroke volume does not plateau during graded exercise in elite male distance runners.

Stroke volume (SV) responses during graded treadmill exercise were studied in 1) elite male distance runners (N = 5), 2) male university distance runners (N = 10), and 3) male untrained university students (N = 10). METHODS: Cardiac output (Q) and SV were determined by a modified acetylene rebreathing procedure. RESULTS: There were no differences in SV responses among the three groups during the transition from rest to light exercise (P > 0.05). However, the rates of change of SV during light to maximal exercise in untrained subjects (slope = -0.1544 mL x beat(-1)) and university distance runners (slope = 0.1041) did not change, whereas it dramatically increased (P < 0.001) in elite distant runners (slope = 0.6734). Moreover, the elite distance runners showed a further slope increase in SV when heart rate was above 160 bpm, which resulted in an average maximal SV of 187 +/- 14 mL x beat(-1) compared with 145 +/- 8 and 128 +/- 14 mL x beat(-1) in the university runners and untrained students, respectively (P < 0.001). Similarly, max Q reached 33.8 +/- 2.3, 26.3 +/- 1.7, and 21.3 +/- 1.5 L x min(-1) in the three groups, respectively (P < 0.001). On the other hand, there was a nonsignificant tendency for maximal arteriovenous oxygen content difference to be lower in the elite athletes compared with the other groups. CONCLUSION: Results from university distance runners and untrained university students support the classic observation that SV plateaus at about 40% of maximal oxygen consumption despite increasing intensity of exercise. In contrast, stroke volume in the elite athletes does not plateau but increases continuously with increasing intensity of exercise over the full range of the incremental exercise test.     

Differences in MCT1 A1470T polymorphism prevalence between runners and swimmers

Skeletal muscle is the major producer and user of lactate in the body. Therefore, transport of lactate across cells' membrane is of considerable importance. Lactate transport is mediated by proton‐linked monocarboxylate transporter (MCT1). The A1470T polymorphism (rs1049434) in MCT1 gene influences lactate transport, with T allele associated with reduction of lactate transport rate and elevation in blood lactate levels. The aim of the current study was to compare allelic and genotype frequencies of MCT1 A1470T polymorphism among Israeli track‐and‐field athletes, swimmers, and non‐athletes. Genomic DNA was extracted from 173 track‐and‐field athletes (age 17–50), 80 swimmers (age 16–49), and 128 non‐athletes (age 19–29). Track‐and‐field athletes were assigned to three subgroups: long‐distance runners, middle‐distance runners, and power event athletes. Swimmers were assigned to two subgroups: long‐distance swimmers and short‐distance swimmers. Genotyping was performed using polymerase chain reaction. T‐allele frequency was significantly higher among long‐distance swimmers (45%) compared with long‐ and middle‐distance runners (27% and 30%, respectively; P < 0.01). In addition, T‐allele frequency was significantly higher among short‐distance swimmers (40%) compared with power event athletes (25%, P < 0.01). Overall, T‐allele frequency was significantly higher among swimmers (42%) compared with runners (27%, P < 0.001). More research is needed to clarify whether this polymorphism displays advantage for swimming performance.     

心肺功能综合评定对优秀径类运动员选才及训练的指导作用

对我国34名优秀径类运动员(男23,女11)进行递增式踏车试验,连续观察(?)E,气促指数,心率,心搏效率,氧脉,(?)O_2max,无氧阈((?)E/(?)O_2,(?)CO_2/(?)O_2曲线的拐点),结果显示,我国男子中长跑运动员(?)O_2显著低于世界水平,而女子长跑运动员则接近于世界水平。综合心肺功能评定可以发现运动员心肺或肌肉功能薄弱环节,为青少年选材提供依据,并可用于评价训练效果。     

The maximally accumulated oxygen deficit as an indicator of anaerobic capacity

Recently, a procedure has been established for the determination of the maximally accumulated oxygen deficit (MAOD) (Medbo et al., J. Appl. Physiol. 64:50-60, 1988) as an indicator of anaerobic capacity. We hypothesized that, if MAOD were a valid indicator of anaerobic capacity, it should distinguish between aerobically and anaerobically trained athletes and correlate with other existing anaerobic testing measures. Subjects were four distance and five middle distance runners, three sprinters, and four controls. The subjects ran for 2-3 min at 125-140% of VO2max until exhaustion, and the accumulated O2 deficit for that run was calculated by an extrapolation procedure. Subjects also performed the Wingate cycle ergometer test and runs of 300, 400, and 600 m. (Only athletes performed the runs.) Post-exercise blood lactates were obtained following the supramaximal treadmill run. MAOD (in O2 equivalents-ml.kg-1) was higher for the sprinters (78) and middle distance runners (74) than for the long distance runners (56) and control subjects (56) (P less than or equal to 0.05), indicating a greater anaerobic capacity for the former two groups. Consequently, the relative anaerobic contribution was larger for the sprinters (39%) and middle distance runners (37%) than for the long distance runners (30%; P less than or equal to 0.05). Significant correlations were found between MAOD and both Wingate power and treadmill work for all subjects and between Wingate power, Wingate capacity, treadmill work, and 300 m time for the athletes, suggesting that relationships do exist among MAOD and other anaerobic test measures. Potential use of MAOD as an indicator of anaerobic capacity is therefore promising and should be further explored.     

Physiological assessment of Saudi athletes.

This study was aimed at assessing the physiological responses of Saudi male athletes to maximal exercise testing. Seventy five national athletes representing nine different sports and fourteen healthy controls were subjected to graded bicycle ergometer tests, during which cardiorespiratory and metabolic functions were monitored and recorded. The results of this study indicate that the maximal oxygen uptake (VO2max) values for the Saudi athletes were not significantly different from those of controls. The cyclists, however, attained the highest VO2max with a mean of 55.05 ml.kg-1.min-1 followed by the middle distance runners (X = 53.17) and the long distance runners (X = 51.19). Comparison of the Saudi athletes with some previously reported international standards revealed that the Saudi athletes had a VO2max that was lower than their respective French, Swedish, Belgian, Norwegian, Italian, Canadian or American athletes.     

Modification of plasma glycosaminoglycans in long distance runners

BACKGROUND: It is well documented that exercise reduces the risk of thromboembolic disease, possibly by increasing the plasma concentration of anticoagulant-antithrombotic compounds. OBJECTIVES: As plasma glycosaminoglycans (GAGs) play a role in the anticoagulant-antithrombotic potential of plasma, to examine the concentration and profile of these compounds in well trained, long distance runners and sedentary subjects. METHODS: Plasma GAGs were measured in 10 male, long distance runners and 10 sedentary counterparts before and after ergometric tests. GAGs were extracted, purified, and identified by electrophoretic and enzymatic methods, and measured as hexosamine. RESULTS: Plasma GAGs found in sedentary subjects were slow migrating heparan sulphates I and II, keratan sulphate I, and chondroitin 4-6-sulphate. Those found in trained athletes were slow migrating heparan sulphate I, chondroitin 4-6-sulphate (or keratan sulphate I), and fast migrating heparan sulphate. Total plasma concentrations of GAGs were higher in athletes than in sedentary subjects at rest. In sedentary subjects, plasma GAGs did not change after cycle ergometric exercise at 80% of their anaerobic threshold. However, the appearance of a novel band of heparan sulphate migrating faster than fast migrating heparan sulphate was observed in athletes after exercise. CONCLUSIONS: Exercise changes the amount and profile of plasma GAGs; these changes may play a role in protecting subjects who practise aerobic sports against developing cardiovascular disease.     

Responses of distance runners and sprinters to exercise in a hot environment

The responses of highly trained distance runners and track sprinters and age-matched untrained men were compared during bicycle ergometry in a 40 degree temperature-controlled environmental chamber. There were no differences among groups in rectal temperature following the 90 min exercise bout. Distance runners had a lower heart rate than either sprinters or untrained subjects. There was no difference in heart rate between sprinters and untrained subjects. Distance runners and sprinters had a much greater sweat rate than untrained subjects and dissipated a greater proportion of their total heat load by evaporation of sweat. Sprinters, however, had a lower sweat rate than distance runners in the hot environment and could only maintain as low a skin temperature as distance runners for 75 min of the 90 min session. Both aerobic training and anaerobic training confer some degree of protection from heat injury during exercise in a hot environment. However, sprinters have a higher heart rate and cannot sustain a low skin temperature as long as distance runners. Sprinters lost their advantage over untrained subjects in skin temperature after 75 min of exercise in a hot environment and did not have a lower heart rate than untrained subjects. Distance runners had a significantly lower heart rate and maintained a lower skin temperature than untrained subjects for the entire 90 min exercise bout.     

Effect of long duration exercise on the ratings of perceived exertion and perceived difficulty of walking and running at the ventilatory threshold

AIM: The purpose of this study was to examine if the relationship between physiological changes classically observed with exercise duration and some subjective workload measures would be affected by the complexity of the locomotion mode (running vs racewalking). METHODS: The study was conducted on 24 well trained subjects (12 long distance runners and 12 racewalkers) divided in 3 groups (runners, racewalkers and control). Energy cost of locomotion (C), heart rate (HR), minute ventilation (V(E)), lactate concentration [La], ratings of perceived exertion (RPE 6-20 scale) and ratings of perceived difficulty (RPD 1(-1)5 scale) were recorded during 2 10-min submaximal tests on a treadmill before and immediately after a 3 hour exercise (racewalking or running) conducted at the velocity ventilatory threshold (vVT). RESULTS: No significant variations in physiological parameters and perceived measures were observed in G(c). A significant increase (p<0.05) in energy cost of walking (mean: +9.4%) and running (mean: +7.5%) at the end of exercise was observed. A significant interaction of locomotion mode and exercise duration was found on perceived exertion and perceived difficulty. In racewalkers RPD significantly increased with duration whereas no significant effect was found for RPE. Conversely a significant increase in RPE was found after 3 hours in runners without any significant change in RPD. CONCLUSIONS: This experiment suggests that, for a complex task, the classical relationship between RPE and metabolic load increase during prolonged exercise could be affected by changes in RPD. In this study, stability in RPE and increase in RPD observed in racewalkers may reflect an attentional focus dissociated from internal sensations and directed toward maintaining the required race walking gait.