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Biomedical subjects

E Kobyliansky

Publications and source records attributed to E Kobyliansky.

At least 91 records · Page 5Linked to original sources
PubMed1978

Handedness, hand-clasping and arm-folding in Israeli males.

Comparative analysis of handedness, hand-clasping and arm-folding frequencies in four groups of adult Israel Jewish males of East European origin (N=562), Central European origin (N=165), Middle Eastern origin (N=191), and North African origin (N=163), indicates a significant similarity between the groups. A high percentage of left-handed individuals was observed in all groups except the Middle Eastern one. Right-hand clasping and left arm-folding predominated in all but the Central European group in which left hand-clasping predominated. When a comparison is made between individuals born in Eastern Europe and those born in Israel to parents of East European origin, the frequency of left handedness was considerably higher among the latter. This may be attributed to an inhibitory effect of the educational system on the expression of sinistrality in the first sub-group. Relationships between handedness and hand-clasping and between hand-clasping and arm-folding was also observed.

Adolescent↗
PubMed1978

Energy absorbing capacity of rat tail tendon at various ages.

Fibres from tail tendons of male rats aged 1--18 months were stretched to breaking point by an 'Instron' tensile apparatus. The energy absorbed during stretching of the tendon was calculated. A sharp increase was found in the energy value during the first 6 months of postnatal life. The following components of this energy were also evaluated: (1) energy absorbed during the period of linear relationship between force and extension; (2) energy absorbed during the period of non-linear relationship. Both components showed rapid increases in value during the first 6 months after birth, after which they levelled off.

Aging↗
PubMed1977

Changes in morphology of human populations due to migration and selection.

Anthropological characteristics of 115 young Israeli-born male Jews (18-25 years), offspring of immigrants from Russia and Poland, are described. The morphological changes in the young group are compared with a sample of 1914 from the "parent" group, and with two non-Jewish European groups--1547 in the 18-25 year age range and 3711 in the 40-60 age range. The results indicate a "migrational effect" acting in young migrant offspring as expressed in higher anthropological values. Statistically significant differences were observed among migrants and the original stationary population. A model is proposed for predicting the expected rate of variation of morphological parameters in the first generation of migrants.

Adolescent↗
PubMedDate not supplied

Evidence on major gene control of cortical index in pedigree data from Middle Dalmatia, Croatia.

It was recently reported that the inheritance of the metacarpal cortical index (CI) in the Chuvashian population can be described in terms of a major gene (MG) model. By applying transmission probability tests, the hypothesis was accepted that not only baseline level of CI but also its sex-specific dependence on age were under control of the same putative large-effect gene. Using a pedigree sample from the population of the islands of Middle Dalmatia, Croatia (847 observed individuals in 278 pedigrees), data are presented to support the above findings. The following hypotheses were accepted: (i) inheritance of baseline CI in the Croatian population can be attributed to the effect of a MG responsible for about 42% of the variation; (ii) the same MG takes part in the control of the dependence of CI on age, particularly the age at onset of involutive bone changes (inflection point), and of the rate of decrease in CI with age (slope coefficient). Issues related to the assortative mating effect on CI and the determination of the most parsimonious model are discussed.

Adolescent↗
PubMedDate not supplied

Mode of inheritance of dermatoglyphic pattern intensity index on fingers in five Indian populations: a comparative study between individual trait and its factor.

Our previous study (Karmakar et al. 2005 Ann. Hum. Biol. 32:445-468) was on 500 pedigrees of five different populations, with factor 1 comprising quantitative finger dermatoglyphics (including pattern intensity index, PII) and factor 1 controlled by major genes. The present results of a complex segregation analysis of the individual trait PII of the same five populations were compared with previous results to ascertain the extent of variation between individual trait PII and its factor (factor 1) with respect to mode of inheritance. The comparative findings are very similar in five populations, irrespective of different ethnic groups. This result suggests that the variability of their biological relevance is influenced by the same genetic component, thus representing a similar mode of inheritance with major gene involvement in all populations.

Adult↗
PubMedDate not supplied

Bone ageing: genetics versus environment.

Bone ageing results from a complex interaction between genetic and environmental factors (such as diet, climate and physical exercise) throughout human life. According to current literature, the most popular measures of bone ageing are osseometric measurements (OSM), bone mineral density (BMD) and osseographic scores (OSS), based on descriptive criteria of bone age. Plain roentgenography allows simultaneous assessment of all three measures. Ethnic differences with regard to these bone ageing characteristics have prompted us to study to the process anew, with the aim of elucidation the nature of the genetic and environmental components involved, and the possible interaction(s) between them. Despite abundant data on ethnic differences regarding these measures, modern knowledge on the genetics of these processes has derived primarily from the family studies of BMD, which pointed to strong involvement of the familial factors on bone mass. Segregation analysis performed by us in two ethnically different samples of pedigrees revealed a significant effect of the putative major gene on BMD of both compact and cancellous bone. The major finding of our bivariate segregation analysis was that it lead to the acceptance of the hypothesis predicating a single major locus with pleiotropy to both cancellous and compact BMD, but clearly rejecting the polygenic hypotheses. Our study of cortical index (CI) provided evidence that a single potential major gene controls not only the baseline trait level, but also the age at onset of the involutive bone changes, and the rate of the CI change with age. When we examined the environmental vs genetic influences on OSS variation in 32 human populations, we found very little environmental effect on the rate of bone change (r2 = 0.107), but a substantial effect on this rate of the genetic differences between populations (r = 0.480). Clarification of the genetic basis of bone ageing could have wide-ranging applications in the prevention and treatment of bone degenerative diseases such as osteoporosis and osteoarthritis, before irreversible damage takes place. There is thus a need to target the genetic analysis of BMD and the biochemical regulating factors of bone turnover through the use of molecular genetic techniques.

Aging↗
PubMedDate not supplied

Modelling of age-related bone loss using cross-sectional data.

BACKGROUND: Current applications of bone mineral density (BMD) data in age studies are not free of certain drawbacks. Since it is well established that age-related patterns of BMD changes involve three distinct periods (bone acquisition in youth, stabilization at maturity, and decrease with ageing), adjusting for age via an inappropriate mathematical function may lead to inconsistencies and wrong conclusions. HYPOTHESIS: The piecewise model, which encompasses the above three periods, will accurately describe the BMD dependence on age. OBJECTIVE: To examine age-related patterns of BMD changes using a number of possible mathematical functions and to find among them the best-fitting function. Next, to test whether the chosen function is universally applicable or if there are diverse population-specific functions. MATERIAL AND METHODS: Thirteen ethnic samples from various regions of Europe and Asia, assigned into five ethnic-geographic groups, were examined. The total sample included 2430 males and 2515 females. Compact BMD of hand phalanges was measured by photodensitometry from plain radiographs of each individual studied. Statistical software was developed for the purposes of the present study; this software gave a maximum likelihood of the parameter estimates for various statistical models (functions). RESULTS: In all samples of sufficient size and representative age range, a two-interval function was found as the best fitting and most parsimonious model to describe the BMD age-related changes. This two-interval function was characterized by age-related bone mass increase, positive slope beta(1s) in young age or a plateau (beta(1s) = 0, i.e. no age-related changes) until a sex-specific age threshold, T(0), after which annual bone loss ensued with a slope coefficient beta(2s). Threshold of BMD loss in women of different ethnic groups ranged between 37.85 and 47.77 years, and roughly coincided with perimenopausal age. In males, the age T(0) varied between 27.85 and 49.07 years. The ensuing cortical bone loss appeared to be linear in both sexes, averaging between 0.51% and 1.15% in men and between 0.74% and 1.77% per year of young age BMD value in females. CONCLUSIONS: The change of phalangeal BMD with age may be best described by a two-interval function, regardless of sex and ethnic background. However, specific parameter estimates depend both on gender and ethnic affiliation. This study has yielded a well-fitted model of BMD dependence on age suitable for further use in population studies.

Adolescent↗
PubMedDate not supplied

Genetics of human body size and shape: body proportions and indices.

BACKGROUND: The study of the genetic component in morphological variables such as body height and weight, head and chest circumference, etc. has a rather long history. However, only a few studies investigated body proportions and configuration. AIM: The major aim of the present study was to evaluate the extent of the possible genetic effects on the inter-individual variation of a number of body configuration indices amenable to clear functional interpretation. SUBJECTS AND METHODS: Two ethnically different pedigree samples were used in the study: (1) Turkmenians (805 individuals) from Central Asia, and (2) Chuvasha (732 individuals) from the Volga riverside, Russian Federation. To achieve the aim of the present study we proposed three new indices, which were subjected to a statistical-genetic analysis using modified version of "FISHER" software. The proposed indices were: (1) an integral index of torso volume (IND#1), an index reflecting a predisposition of body proportions to maintain a balance in a vertical position (IND#2), and an index of skeletal extremities volume (IND#3). Additionally, the first two principal factors (PF1 and PF2) obtained on 19 measurements of body length and breadth were subjected to genetic analysis. Variance decomposition analysis that simultaneously assess the contribution of gender, age, additive genetic effects and effects of environment shared by the nuclear family members, was applied to fit variation of the above three indices, and PF1 and PF2. RESULTS: The raw familial correlation of all study traits and in both samples showed: (1) all marital correlations did not differ significantly from zero; (2) parent-offspring and sibling correlations were all positive and statistically significant. The parameter estimates obtained in variance analyses showed that from 40% to 75% of inter-individual variation of the studied traits (adjusted for age and sex) were attributable to genetic effects. For PF1 and PF2 in both samples, and for IND#2 (in Chuvasha pedigrees), significant common sib environmental effects were also detectable. CONCLUSION: Genetic factors substantially influence inter-individual differences in body shape and configuration in two studied samples. However, further studies are needed to clarify the extent of pleiotropy and epigenetic effects on various facets of the human physique.

Adolescent↗
PubMedDate not supplied

Complex segregation analysis of quantitative dermatoglyphic traits in five Indian populations.

OBJECTIVE: Dermatoglyphics is widely used as a genetically determined trait in anthropogenetics although the genetic nature of its inheritance is still inconclusive, due to the lack of any established genetic model to resolve the existing inconsistencies in the literature. However, advanced statistical packages for complex segregation analyses are available and the aim of the present study is to determine the mode of dermatoglyphic trait inheritance in five different ethnic populations. METHODS: Five hundred families (2435 individuals) of two generations were used for principal component analysis, familial correlation and segregation analysis (package MAN-5). RESULTS: The similarity of three factors suggests a common internal structure. Significant familial correlation (except spouse) indicates the involvement of a familial component in the variation of dermatoglyphic traits. Segregation analyses suggest the transmission of a genetic effect in the families which follows the Mendelian model and confirms a major gene effect on factor 1 and factor 2 with two co-dominant alleles. There is no evidence of a major gene effect or environmental effect on factor 3 (a-b ridge counts). The nature of transmission and trait variance (H2) strongly supports the existence of a common nature of dermatoglyphic trait inheritance in populations, irrespective of ethnic and geographic area. CONCLUSION: Major gene involvement in finger dermatoglyphics according to Mendelian models is confirmed.

Analysis of Variance↗
PubMedDate not supplied

Jewish populations of the world: genetic likeness and differences.

In six Jewish populations from Eastern, Central and Southern Europe, the Middle East, North Africa and Yemen, the frequencies of 30 genes from 13 loci were determined. The calculation of genetic distances between these populations as well as a cluster analysis were done. The gene frequencies of these six populations were computed together with those of 19 other Jewish populations of diverse countries described in the literature. Of the 19 populations, 22 alleles from 10 loci were checked. Gene frequencies in autochthonous, non-Jewish populations from these countries were also computed. All Jewish populations except Yemenites are concentrated in the same cluster, being closer one to another than to any of the non-Jewish groups. A similar picture is obtained when Jewish and non-Jewish populations from 19 countries are subjected to cluster analysis. The differences between the Jewish populations generally tend to bring them closer to the corresponding non-Jewish groups. The present data suggest that these differences cannot always be explained by admixture; other factors such as the effect of convergent adaptive processes must be considered.

ABO Blood-Group System↗
PubMedDate not supplied

Genetic composition of Jewish populations: diversity and inbreeding.

Genetic diversity and F statistics analysis, using 9 and 5 blood group loci, respectively, were carried out on 16 Jewish populations from 5 geographic regions: East Europe, Central Europe, South Europe, Middle East and North Africa. The proportion of total diversity found within populations was 98.9% while that between populations, within geographic groups and between groups altogether was only 1.1%. The average heterozygosity between geographic groups ranged from 0.3867 to 0.4150. There were no significant differences between geographic groups of populations in heterozygosity or in its variance. Average estimates of inbreeding were as follows: Fis = 0.0419, Fst = 0.0084 and Fit = 0.0498. Because the heterogeneity and relative proportion of diversity were less between Jewish populations than between non-Jewish ones, we conclude that genetic similarity between Jews is higher than between Gentiles. The findings are in agreement with our previously obtained calculations of genetic distances (Kobyliansky, Micle, Goldschmidt-Nathan, Arensburg and Nathan 1982).

Africa, Northern↗
PubMedDate not supplied

A morphological approach to the problem of the biological similarity of Jewish and non-Jewish populations.

The genetic kinship between various Jewish and non-Jewish groups, from the biochemical standpoint, has been much investigated, frequently with very contradictory conclusions. The present paper reports the results of two comparative analyses of several Jewish and non-Jewish populations as based on morphological measurements of adult males. The first analysis employed data on Jewish and non-Jewish communities from five geographic regions of the world. The dendrogram resulting from the cluster analysis clearly indicates that Jewish populations are much closer to one another than to non-Jewish neighbour groups. In the second analysis, 25 ethnoterritorial groups of the USSR (one Jewish and the rest non-Jewish) were evaluated on the basis of 27 anthropometric characters. The latter Jewish group was markedly separate from the other 24 ethnic groups, and especially distinct when only traits with high coefficients of heritability were employed.

Adult↗
PubMedDate not supplied

Study of genetic variance in the fluctuating asymmetry of anthropometrical traits.

We have studied the fluctuating asymmetry (FA) of 8 bilateral morphometric traits in two-parent families, comprising 216 families with one newborn baby, and 60 families with two children (age range 5-18 years). Heritability was assessed by: (1) multiple regression analyses of the children's measurements on the mother's and father's measurements; (2) midparent-child regressions; and (3) sibling correlations. The extent of genetic determination of individual FA measurements was generally low, albeit statistically significant in some cases. However, even these correlations were inconsistent between samples and relatives. However, the mean FA values for all 8 studied traits showed positive and significant correlation between parents and children in two samples and in total. Additive genetic variance, calculated from multiple regression analyses and midparent-child correlations, was estimated to be between 0.25-0.30. Three multiple regressions (two for the separate group and one for the total sample) yielded a statistically significant value (between 0.21-0.33) also for the non-additive genetic component.

Adolescent↗
PubMedDate not supplied

Relationship between physical traits and rate of some common illnesses in newborn infants.

The morbidity rates of newborn infants suffering from jaundice or urinary tract infections (UTI) as well as total morbidity were determined in morphologically different groups of 1088 newborn infants. On the basis of body weight, body length, head circumference and Quetelet's index; the surveyed neonates divided into a modal (MI = mean +/- 0.67 SD) and two extreme groups: small (SI less than MI) and large (LI greater than MI), for each variable. The results show that, in general, infants with high morbidity, including those suffering from jaundice and UTI, have lower values of all the mentioned morphological traits than do healthy infants. Discriminant analyses of sick and healthy infants (three pairs of comparisons) indicate that decreased weight at birth is typical for all studied categories of morbidity. An additional finding was that infants suffering from UTI or other types of morbidity (total morbidity) originate from small-sized families in which the parents are generally older and the mother tends to be short and overweight.

Anthropometry↗
PubMedDate not supplied

Age-dependent changes in morphometric and biochemical traits.

This morphometric investigation was based on an anthropological cross-sectional study of five age groups in Israel: (1) newborn infants; (2) 7-year olds; (3) 18-29 years old; (4) 30-60 years old; and (5) 80 years and older. Fluctuating asymmetry (FA) of eight bilateral traits and coefficients of variation (CV) for 21 standard anthropometric traits were investigated in these groups. The results show that the values of FA and CV increase significantly among older people. The frequency of blood groups and enzymatic alleles (13 polymorphic systems), as well as heterozygosities (H), were estimated in two age groups: adults (33-45 yr) and old (80-85 yr) people. Gene frequency distributions conformed with the Hardy-Weinberg equilibrium and were similar in both these populations. Estimates of mean individual H were nonsignificantly lower in the old population.

Adolescent↗
PubMedDate not supplied

Genetics of human body size and shape: complex segregation analysis.

The genetic component in a mixed heritability model, including major gene, multifactorial and sibling environment transmissible components, was studied for some 20 anthropometric traits in two ethnically different samples. The first sample comprised 305 Mexican nuclear families, and the second comprised 83 Ashkenazi Jewish nuclear families living in Israel. All variables, after adjustment for age and sex, were subjected to principal-components analysis (PCA) in each sample separately. The mixed model of inheritance as implemented in the computer program POINTER was used in the present study. An attempt was made to evaluate genetic effects in the variation of the first principal components (PCs). PCA showed a clear separation of variables and was easily interpretable. The PC1 was a credibly general size factor. This factor alone accounted for about 30% of the total variance. Other components are rather shape factors for various combinations of traits. The testing of several genetic hypothesis showed the following: (1) For all factor scores the genetic component was high and statistically significant. (2) In a Mexican sample, for PC1 and PC2, both major gene and polygenes contributed significantly to the total variation of these variables; in the major locus the alleles were most probably codominant. (3) For all other PCs the major gene effect hypothesis was rejected, with more than 50% of the variation attributable to the polygenes contribution. (4) No evidence was found for sibling environmental resemblance in either sample.

Adolescent↗
PubMedDate not supplied

Genetics of human body size and shape: pleiotropic and independent genetic determinants of adiposity.

The present study utilized pedigree data from three ethnically different populations of Kirghizstan, Turkmenia and Chuvasha. Principal component analysis was performed on a matrix of genetic correlations between 22 measures of adiposity, including skinfolds, circumferences and indices. Findings are summarized as follows: (1) All three genetic matrices were not positive definite and the first four factors retained even after exclusion RG > or = 1.0, explained from 88% to 97% of the total additive genetic variation in the 22 trials studied. This clearly emphasizes the massive involvement of pleiotropic gene effects in the variability of adiposity traits. (2) Despite the quite natural differences in pairwise correlations between the adiposity traits in the three ethnically different samples under study, factor analysis revealed a common basic pattern of covariability for the adiposity traits. In each of the three samples, four genetic factors were retained, namely, the amount of subcutaneous fat, the total body obesity, the pattern of distribution of subcutaneous fat and the central adiposity distribution. (3) Genetic correlations between the retained four factors were virtually non-existent, suggesting that several independent genetic sources may be governing the variation of adiposity traits. (4) Variance decomposition analysis on the obtained genetic factors leaves no doubt regarding the substantial familial and (most probably genetic) effects on variation of each factor in each studied population. The similarity of results in the three different samples indicates that the findings may be deemed valid and reliable descriptions of the genetic variation and covariation pattern of adiposity traits in the human species.

Adipose Tissue↗