Physical and pubertal development in young male gymnasts.

The purpose of this study was to evaluate the effect of intense training on physical growth and sexual maturation in young male gymnasts. Physical development, pubertal development, testosterone levels, energy expenditure, and relative body fat were examined in 21 circumpubertal male gymnasts (13.3 +/- 0.3 yr) and 24 age-matched controls (13.5 +/- 0.3 yr). Subjects completed a self-assessment of genital and pubic hair development with the use of the Tanner scale. All subjects were measured for height, weight, and salivary testosterone levels (T). The Physical Activity Questionnaire for Adolescents was used to estimate weekly energy expenditure in metabolic equivalents. Percent body fat (%BF) was assessed by using bioelectrical impedance analysis. Developmental stages and T, as well as height and weight, were not different between groups. Energy expenditure was significantly higher (P 相似文献   

Hormonal responses to physical training in high-level peripubertal male gymnasts

The effects of performing intensive training during growth remains controversial, with claims of negative effects upon growth and maturation purportedly due at least in part to a combination of hormonal disturbances and inappropriate nutrition. We examined the training-related responses of total testosterone (T), insulin-like growth factor-1 (IGF-1), cortisol (C) and diet in 16 peripubertal (pubertal stage <2) male gymnasts [mean (SD) age 10.5 (0.9) years, training 17.2 (5.6) h x week(-1)] and 17 controls [mean (SD) age 9.6 (1.2) years] over a 10-month period. Fasted, resting morning blood samples (0730-0900 hours) were taken from all children on Monday, Wednesday and Friday during a single week towards the end of each of three phases of gymnastics training: routine development (RD), precompetition (PC) and strength conditioning (SC). Serum concentrations of T, C and IGF-1 did not differ between the groups at any time. The ratio between IGF-1 and cortisol was significantly reduced in gymnasts relative to controls during RD and SC training (P<0.05), although no differences were detected for the T:C ratio. Diet did not correlate with any of the hormonal measurements, and no intergroup differences were found for the rate of growth in height. In summary, these results suggest that either the gymnastics training performed by these subjects was not intense enough to alter adrenal function, or that the gymnasts were well adapted to the training. In contrast, the reduction in the anabolic to catabolic balance represented by the IGF-1:C ratio is suggestive of a catabolic state, perhaps resulting from overstrain, insufficient recovery and/or inadequate caloric intake relative to energy output. While physical training during growth may induce a catabolic state, further research is needed to determine the biological significance of this finding, particularly with regard to growth and maturation.     

Plyometric jumping performances of male and female gymnasts from different heights

The objective of this study was to investigate and compare the factors influencing plyometric jumping performance between well-trained gymnasts and a control group. Seventy-six gymnasts and 91 moderately active subjects volunteered to participate in this study. Drop jumps (DJ) were performed from 20-, 40-, 60-, 80-, and 100-cm heights. Flight time (FT) and contact time (CT) were recorded using contact mat. Flight time to contact time (FC) ratio and Bosco expression (BE) were calculated. Male gymnasts scored similar FT to their controls, whereas female gymnasts had significantly longer FT compared with their peers. The gymnasts obtained significantly shorter CT than their control groups, whereas their FC ratios were significantly higher and increased when the height of the drops was close to 60 cm. Moreover, gymnasts' BE was greater in comparison to their respective control groups independent of the drop height. The height of the drop that produced the best FC ratio and BE varied between the groups. The best performances were obtained between 40- and 60-cm drop height for both groups. Female control group showed a trend toward a continuing decline with the increase of the drop height. The best gymnasts (finalists at World Championships) obtained their best performance at 80-cm drop. Flight time is the less discriminating factor distinguishing gymnasts' DJ performances. Considering CT, FC, and BE results all together could better profile the gymnasts rather than taken separately. Bosco expression was shown to be more sensitive to the increase in FT; we suggest BE as the best criteria to assess the appropriate drop height for plyometric training purposes in gymnasts as it has been significantly correlated to FT.     

甘薯象空间格局及抽样技术研究

通过空间分布型指数分析,甘薯象对薯块、著株危害空间分布型为随机分布或均匀分布;同时确定了理论抽样数     

A role for the adult fat body in Drosophila male courtship behavior

Mating behavior in Drosophila depends critically on the sexual identity of specific regions in the brain, but several studies have identified courtship genes that express products only outside the nervous system. Although these genes are each active in a variety of non-neuronal cell types, they are all prominently expressed in the adult fat body, suggesting an important role for this tissue in behavior. To test its role in male courtship, fat body was feminized using the highly specific Larval serum protein promoter. We report here that the specific feminization of this tissue strongly reduces the competence of males to perform courtship. This effect is limited to the fat body of sexually mature adults as the feminization of larval fat body that normally persists in young adults does not affect mating. We propose that feminization of fat body affects the synthesis of male-specific secreted circulating proteins that influence the central nervous system. In support of this idea, we demonstrate that Takeout, a protein known to influence mating, is present in the hemolymph of adult males but not females and acts as a secreted protein.     

Body composition and fat distribution pattern of urban elderly females, Delhi, India

The present study was conducted on females (n = 279) in the age range of 51-89 year, living in the urban dwellings of Delhi, India. Another group of 21-25 years old young adult females was taken as a control group. A total of 14 anthropometric measurements were taken: stature, sitting height, weight, skinfold thickness at nine different sites over the body and body girths such as upper arm, waist and hip circumference. Indices like body mass index, grand mean thickness, waist-hip ratio were computed to assess the body composition. Fat profile and responsiveness of different skinfold sites towards fat accumulation were studied to find out the regional fat distribution with advancing age. Redistribution of body fat was found to take place with increasing age. A relative preponderance of upper body fat was visible among elderly subjects. However, a clear reverse trend was observed in the young control group females. Significant differences were observed with regards to the body composition and fat profile between young adult females and test group females. Abdomen and the sub-scapular area were reported to be the most sensitive sites for fat deposition as the age advanced. The stature and sitting height showed significant decline with age. All the indices of adiposity i.e. grand mean thickness, waist-hip ratio and body mass index revealed significant changes in elderly females when compared with young adult control group females.     

Heterogeneity of DNA distribution pattern in colorectal carcinoma. A microspectrophotometric study of fine needle aspirates

For 50 consecutive patients with colorectal carcinoma, the nuclear DNA content in four separate fine needle aspiration samples taken from the resected tumors was analyzed using single-cell Feulgen cytometry. The DNA distribution patterns were divided into four classes according to their degree of euploidy/aneuploidy. Twenty tumors (40%) displayed a similar DNA pattern in all four samples while 30 tumors (60%) were heterogeneous, with a different DNA pattern within one or more of the four samples. None of the tumors were homogeneously diploid. These results illustrate the importance of multiple biopsy samples in the evaluation of the DNA pattern in colorectal tumors.     

Circum-menarcheal bone acquisition is stress-driven: A longitudinal study in adolescent female gymnasts and non-gymnasts

Mechanical loading through youth exercise is highly modifiable and represents a strategy to maximize peak adult bone mass, with the potential for broad implementation across the population to lower fracture risk. For girls, circum-menarcheal growth is critical, with around 50% of adult bone acquired over a 4-year period. Here, we prospectively followed 10 gymnasts and 12 age-matched non-gymnasts across approximately 4 years circum-menarche. A combination of pQCT and subject-specific finite element models were used to measure differences in bone acquisition and structure between the groups, and to determine the degree to which specific mechanical factors predict change in bone structure. At baseline, gymnasts had stronger bone, including 26% higher BMC, 51% greater compressive strength, and 21% higher trabecular density. Over the study period, both groups more than doubled their bone strength. Pre-menarcheal principal stresses predicted change in pQCT variables for non-gymnasts, but not gymnasts. The bone of non-gymnasts became more asymmetrical than the bone of gymnasts. Our results suggest that exposure to the diverse, intense mechanical signals of gymnastic loading during adolescence imparts substantial benefits to bone geometry and mechanical function. Specifically, the bone of gymnasts is better able to resist loading from multiple directions, and operates with a higher factor of safety compared to non-gymnasts.     

Scalp expansion in the treatment of male pattern baldness

Tissue expansion has been extremely valuable in the treatment of traumatic scalp defects. We have recently used expansion techniques in the treatment of male pattern baldness. Expansion has been used in conjunction with scalp-reduction procedures and pedicled hair-bearing flaps. Flaps have been designed as Juri flaps, and in one patient, a new posteriorly based flap was used. This design gives the advantage of a more natural-appearing hairline and forward-growing hair. The major advantage of tissue expansion in the treatment of male pattern baldness is that it generates new hair-bearing scalp. The increase in vascularity which occurs during expansion allows for large, safe, and predictable flaps. Donor sites are also relatively easily closed. The disadvantages of expansion include the need for two or more surgical procedures and multiple office visits. There is also some discomfort following expansion and a cosmetic defect as the expanders become larger. Complications include infection, exposure or extrusion, deflation, and hair loss. Tissue expansion combined with scalp reduction and pedicled hair-bearing flaps have proved to be a valuable technique in the treatment of male pattern baldness with a high degree of patient satisfaction.     

缙云山川鄂连蕊茶种群空间分布格局研究

采有相邻格子样方法取样,应用方差／均值比的t检验、负二项参数、Cassie指标、扩散型指数、丛生指标、平均拥挤度和聚块性指数等方法,研究了川鄂连蕊茶种群的空间分布格局。结果表明,在不同群落类型中,川鄂连蕊茶空间格局均为集群分布,但集群程度有差异。同时,还对不同发育阶段川鄂连蕊茶种群的分布格局进行了分析,从幼苗到成体,其集群强度由大到小。     

中国鸢尾属植物根茎中异黄酮类成分分布的初步研究及其系统学意义

本文对鸢尾属Iris 22个种(基本上包括了各个亚属的代表)及其近缘属植物射干属Belamcanda的 射干 B．chinensis(L．)DC．进行了根茎的异黄酮类成分的比较分析研究。结果表明,鸢尾属植物和射干 中普遍具有异黄酮类成分,这是它们的特征性成分之一。根据化学成分的特征,鸢尾属可以分为两大类 群：只含异黄酮甙元的类群和既含异黄酮甙又含甙元的类群。从化学成分的分布特征来看,无附属物亚 属subgen．Limniris只含异黄酮甙元,是一个比较自然的类群。鸡冠状附属物亚属subgen．Crossiris,除小 花鸢尾 I．speculatrix Hance外,是一个较自然的类群。野鸢尾亚属subgen．Pardanthopsis和射干属的成分 非常相似,有着密切的亲缘关系,是鸢尾属中原始的类群。从化学成分特征来看,野鸢尾亚属与琴瓣鸢 尾亚属subgen．Xyridion、鸡冠状附属物亚属、须毛状附属物亚属subgen．Iris都有着一定的联系。根据化 学成分、孢粉学、细胞学等特征,认为：华夏鸢尾I．cathayensis Migo和长白鸢尾I．mandshurica Maxim．为无附属物亚属与须毛状附属物亚属两亚属之间的过渡类型。小花鸢尾是无附属物亚属向鸡冠状附属物亚属过渡的中间类型。扁竹兰I．confusa Sealy和扇形鸢尾I．wattii Baker可能是同一个种。     

A preliminary study on the distribution pattern of isoflavones in rhizomes of Iris from China and its systematic significance

A comparative isoflavonoid analysis of 22 species of Iris, representing almost all the subgenera, and one species of its allied genus Balamcanda, B. chinensis (L.) DC. was carried out by TLC, with iridin, tectoridin, irigenin, tectorigenin, irisfloretin, dichotomin, wogonin, rhamnazin, apocynin, androsin being used as authentic compounds. The results show that the isoflavones are the characteristic constituents of Iris and Belamcanda. According to the distribution pattern of isoflavones, the Iris species here studied can be divided into 2 groups; one contains isoflavonoid aglycons, while the other contains both glycosides and isoflavonoid aglycons. From the point view of chemosystematics, subgen. Limniris contains isoflavonoid aglycons only and might be a natural group; subgen. Crossiris might be also a natural group when Iris speculatrix Hance is excluded; subgen. Pardanthopsis is similar to B. chinensis in the chemical constituent might be a primitive group in Iris and has close relationship with subgen. Crossiris, subgen. Xyridion and subgen. Iris. Based on the evidence from phytochemistry, palynology and cytology, Iris cathayensis Migo and I. mandshurica Pall. are considered intermediate groups between subgen. Limniris and subgen. Iris and I. speculatrix Hance an intermediate group between subgen. Limniris and subgen.Crossiris, while I. confusa Sealy and I. wattii Baker might be conspecific.     

A comparative study in young male animals of 10 species of the distribution of alkaline phosphatase activity in small arteries

Summary The distribution of alkaline phosphatase activity in the walls of small arteries measuring 100–200 in internal diameter in the collapsed state was investigated in nine organs in male animals of each of ten species employing the Gomori and azo-coupling techniques. Alkaline phosphatase activity was high in relation to the arterial endothelium of the chick, hen, turkey, rabbit, frog and man but was related to the arterial adventitia and not to the endothelium in the rat. In the guinea pig and hamster arterial alkaline phosphatase activity was uniformly low or absent. Within nine of these ten species the pattern of organ distribution of arterial alkaline phosphatase activity in vessels of comparable size was uniform. In the cat however, enzyme activity was confined to the adventitia of small cerebral arteries and to the media of the smallest arteries (arterioles) in all organs except the testis from which arterial activity was absent.The distribution of alkaline phosphatase activity in 100–200 , arteries in the species investigated was not directly related to the presence of capillary endothelial activity which was detected in all the organs examined. The activity in the walls of the smallest arteries (arterioles) was located in different sites in different species.United Arab Republic Research Fellow.