Associations between the rates of maturation and growth in the short bones of the hand

Serial radiographs of the hand-wrist were used to analyze the associations within bones between the rates of change in skeletal maturity, diaphyseal and epiphyseal lengths and diaphyseal width. In previous studies of these children, it has been shown that these rates are linear in relation to chronological age. The associations between the rates of change in these parameters were analyzed using the slopes (b values) for regression lines flitted to the data in each child. In individual bones, most of the correlation coefficients were moderate to low; some were negative. For most associations in each sex they were relatively high for metacarpal II. The rates of skeletal maturation and diaphyseal elongation were correlated more highly in the girls than in the boys but the rates of skeletal maturation and epiphyseal elongation were correlated more highly in the boys. When bones were considered in groups, relatively high correlations were noted for the metacarpals and ray II, lower correlations were common for the middle and distal phalanges. There was no evidence of real neighborhood effects but marginal effects were present.     

男性青少年脂肪组织分布与相对骨龄的关系——Fels追踪研究

本文对Fels追踪研究中8—17岁男性青少年的相对骨龄与脂肪分布类型之间的关系做了分析。按体重/身高~2调整后,如用每个年龄的三种皮褶厚度(ST)指数的均值表示脂肪分布类型的话,8—12岁时,脂肪分布类型呈外周型分布,但13岁后开始朝向心型发展呈全身性分布。如用肩胛下ST/(肩胛下ST+肱三头肌区ST)的比例表示的话,那么14—17岁时,相对骨龄早者(简称早组)与相对骨龄晚者(简称晚组)相比,前者有较明显的向心型分布倾向。13—14岁时,早组的上述比值的年增长明显大于晚组。但是,按脂肪分布类型指数等级的基线和体重/身高~2调整之后,7、11或14岁时的相对骨龄不能预测17岁时的脂肪分布类型指数的等级。所以,我们可以得出这样的结论:如按本文的比例指数加以定量的话,脂肪分布类型与男性青少年的相对骨龄只有微弱的关系。他们的脂肪分布类型可能与其它成熟指征(如男性青春期的第二性征)有明显的关系。     

Heritability and components of phenotypic expression in skin reflectance of Mestizos from the Peruvian Lowlands

Skin reflectance was measured on the inner upper arm and forehead of a sample of 209 Mestizos ranging in age from 2 to 64 years living in the town of Lamas in the Eastern Peruvian Lowlands. The sample consisted of 43 father-son, 42 father-daughter, 62 mother-son, and 70 mother-daughter pairs. The sample also consisted of 57 brother-brother, 60 sister-sister and 139 brother-sister pairs. The reflectance measurements were made with a Photovolt Reflection Meter, model 670. Stepwise polynomial regression techniques were used to derive standardized residual values. Then using these residual values parent-offspring, sibling intraclass correlations and components of the phenotypic expression of skin reflectance were calculated. The study indicates that 1) the parent-offspring and sibling correlation coefficients conformed with the theoretical correlations expected assuming polygenic inheritance; 2) the husband-wife correlations indicate a high degree of assortative mating for skin color, but despite this effect the parent-offspring and sibling correlation coefficients are lower than the values expected under the influence of autosomal genes; 3) estimates of heritability and components of phenotypic expression indicate that about 55% of the total variability in skin reflectance could be attributed to the influence of additive genetic factors; and 4) there is no evidence of X-linkage in the inheritance of skin color.     

Fatness and skeletal maturity of Belgian boys 12 through 17 years of age

Relationships between fatness and skeletal maturity are considered in a nationwide sample of 14,259 Belgian boys 12 through 17 years of age (The Leuven Growth Study of Belgian Boys). Absolute fatness was estimated from four skinfolds using the Drinkwater and Ross technique and from the sum of four skinfolds, and was related to skeletal maturity assessed by the Tanner-Whitehouse method (I and II). In addition, comparisons were made between the fattest 5% and leanest 5% of the boys at each age level. Correlations between the indices of fatness and skeletal age and relative skeletal age (the difference between skeletal and chronological ages) are positive and generally low, ranging from 0.12 to 0.39. They tend to decrease with age from 12 to 17 years. Comparisons between the extreme groups indicate that the leanest boys are more delayed in skeletal maturity, by about 0.8 years, than the fattest boys are advanced, by about 0.5 years. Stature data for the same boys are consistent with the skeletal maturity data and thus suggest that the size differences between the extreme groups are due in part to maturity differences. Over the age span 12 through 20 years, the leanest boys are reduced in stature by about – 1.2 standard deviations, while the fattest boys are larger in stature by about +0.6 standard deviation units. The size differences, however, persist after skeletal maturity is attained so that there may be a specific role for fatness in influencing statural growth.     

Single versus serial assessment of skeletal age: Either,both or neither?

Assessments of skeletal age are a valuable adjunct to the clinical evaluation of physical maturity but are more meaningful when considered in relation to chronological age, especially over time, than as separate entities. Data on 51 girls from the Child Research Council study series gave a correlation coefficient of 0.51 between skeletal age (SA) at menarche and chronological age (CA) at menarche — a value in close agreement with data reported from other studies. With a range in SA of 11.58 to 14.89 years, these data were examined further for changes in SA related to timing of adolescence. SA was greater than CA in each of the nine girls whose menarche occurred between 10.5 and 12 years of age. SA was equal to CA in one girl, greater than CA in eight girls and less than CA in 11 girls with menarche between 12.15 and 13.4 years. Of the 22 girls with menarche after 13.5 years, one had SA = CA at 14.89 years and the other 21 all had SA less than CA. An r of 0.84 was calculated between the values of CA minus SA at menarche and CA at menarche. Similar relationships were found between SA and CA at age of maximum increment in growth in height for these girls and for 53 boys in the study series. Longitudinal data for height, weight and SA for four boys and five girls demonstrate the problems of prediction of the timing of adolescence and of adult size from skeletal ages in the childhood years.     

Skeletal maturity of Japanese children in Western Kyushu

This paper describes the skeletal maturity status of Japanese children in Western Kyushu and its variation within Japanese populations. Hand-wrist skeletal maturity was assessed by the Tanner-Whitehouse (1975) (TW2) method from radiographs of 500 boys and 485 girls aged from 4 to 15 years. Western Kyushu children showed retarded skeletal maturity scores (RUS, carpals, and 20-bone) under the age of 12 years for boys and 10 years for girls, and thereafter they were advanced in relation to the British standard. Within Japanese populations the present sample showed delayed maturity compared to Tokyo children, but was close to that of Sapporo children throughout the age range studied. However, the expected effect of secular trend suggested skeletal maturity more advanced for Tokyo children and somewhat advanced one for Sapporo children compared to that of Western Kyushu children.     

Age-related mitochondrial genotypic and phenotypic alterations in human skeletal muscle

To have a clearer picture of how mitochondrial damages are associated to aging, a comprehensive study of phenotypic and genotypic alterations was carried out, analyzing with histochemical and molecular biology techniques the same skeletal muscle specimens of a large number of healthy subjects from 13 to 92 years old. Histochemical data showed that ragged red fibers (RRF) appear at about 40 years of age and are mostly cytochrome c oxidase (COX)-positive, whereas they are almost all COX-negative thereafter. Molecular analyses showed that the 4977 bp deletion of mitochondrial DNA (mtDNA(4977)) and the 7436 bp deletion of mtDNA (mtDNA(7436)) are already present in individuals younger than 40 years of age, but their occurrence does not change with age. After 40 years of age the number of mtDNA deleted species, as revealed by Long Extension PCR (LX-PCR), increases, the 10422 bp deletion of mtDNA (mtDNA(10422)) appears, although with a very low frequency of occurrence, and mtDNA content is more than doubled. Furthermore, mtDNA(4977) level directly correlates with that of COX-negative fibers in the same analyzed subjects. These data clearly show that, after 40 years of age, the phenotypic and genotypic mitochondrial alterations here studied appear in human skeletal muscle and that they are closely related.     

Growth of skeletal components in the young squirrel monkey (Saimiri sciureus boliviensis): a longitudinal experiment

A functional skeletal criterion, as an extension of the van der Klaauw's cranial theory, was adopted in the present study. The null hypothesis tested was: "The major skeletal components of the platyrrhine body grow linearly, regardless of their functional dependence to different demands." The acceptance of the hypothesis will imply that all Saimiri skeletal growth may be satisfactorily explained by independent variables in a single equation. The rejection will suggest that such skeletal growth patterns have to be explained by variables in several different equations, and perhaps these equations may vary with the effect of sex and undernutrition. Control and undernourished squirrel monkeys were radiographed monthly for 2 years; they were also measured; and their volumetric and morphometric neurocranial, facial, and pelvic indices were calculated. The curves that best described each of the 24-point sequences were obtained. Three main growth patterns were observed: 1) Simple linear (femur length for all groups, and pelvic index for control and undernourished females), for which the simple regression equation explained more than 95% of the variation; 2) Complex linear (pelvic index for control and undernourished males, and neurocranial and facial indices for all of the groups), for which more than 95% of the variation was explained by one of the four four-function type equations; and 3) Noncorrelated with age (neurofacial index for undernourished males, and pelviofemoral index for control females and undernourished males and females), which showed nonsignificant correlations with respect to age. The food intake and the oscillations of the environmental temperature might help to explain the undulating growth trajectory observed in the complex linear components.     

Associations between the rates of maturation of the bones of the hand-wrist

Skeletal maturation rates for the age interval 3 to 13 years were analyzed using bone-specific assessments (Greulich-Pyle) of serial radiographs of 40 children. The mean rates of skeletal maturation resembled those of the population from which the atlas standards had been derived. There was a linear trend of skeletal age against chronological age for most bones in each sex. Regression lines were fitted to these data and the b values of the regression lines were calculated. Communality indices were calculated from an intercorrelation matrix of these b values. There was a statistically significant rank order correlation between the sexes in the communality indices. They tended to be higher in the girls than in the boys and were relatively low for the radius, ulna and carpals. Communality indices within groups of bones were high in all rows, especially the metacarpals, but in each sex they were comparatively low in the first ray (metacarpal plus the phalanges of the corresponding digit) and in the fifth ray of the boys. Neighborhood effects on the levels of association of maturation rates were present, particularly in the carpus, but marginal effects were not noted.     

Association between physique characteristics and hand skeletal aging status

The aim of the present study was to evaluate the association between skeletal aging traits (obtained from evaluation of hand radiographs) and physique characteristics, including indices of obesity, skeletal size, muscular development, and the somatotypes of Heath and Carter (1967) and of Deriabin (1985). To achieve our aims, we used multiple regression analysis, and Pearson's and canonical correlation analyses. The studied population comprised 629 males and 561 females aged 18-90 years, all members of the Chuvasha (Russian Federation). The present study provides evidence for a connection between hand bone aging traits and physique characteristics. The cortical index showed a small but significant correlation with adiposity and the index of overall physique, but bone mineral density (BMD) traits were not correlated with the index of overall physique. Deriabin's set of somatotypes was significantly correlated with BMD, but could explain only 2% of its variation. Significant correlations of the hand osteoarthritis trait were observed with indices of adiposity. Also observed were statistically significant canonical correlations with both sets of somatotypes, which enabled us to predict 2-3% of hand osteoarthritis variation by a combination of somatotype components. Osseometric score evinced statistically significant correlations with most indices of physique as well as with a combination of somatotype components. These findings may prove helpful in epidemiological studies, because they show that body composition is the factor that is statistically significantly associated with skeletal aging.