Biomedical subjects
Publications and source records attributed to E Kobyliansky.
Relationship between the variability of 5 independent morphological characters and the heterozygosity level at 4 blood group loci were determined in Israel. An increase in the heterozygosity level led to a reduction of the range and coefficient of variation of the morphological traits and also led to an increase of modal phenotype frequencies in the group.
The relationships between the variability of 48 morphological traits and the heterozygosity of four blood group loci were studied in 200 Israeli Jewish males of Eastern European origin aged 18-22 years. A definite correlation was observed between the level of heterozygosity and the variability of 17 traits and two indices. Of the latter traits only 10 were chosen for further analysis. Principal component analysis showed that seven of these traits were independent. For six of them, the frequency of modal individuals (average +/- 0.67 S.D.) in the tetraheterozygous group was the highest, diminishing proportionally with decreasing heterozygosity levels. The degree of heterozygosity also had a significant negative correlation with the coefficient of variation of the morphological characters and was positively associated with the kurtosis values. Only the variability of one of 10 traits showed an opposite trend and a correlation with biochemical homozygosity. The results are discussed in terms of developmental homeostasis.
Changes in the genetic and environmental components of the phenotypic variance of 20 morphological characters were studied in Mexican migrant and sedentary populations. As far as the changes in variance components and the average values of traits were concerned, it was found that some traits were subjected to different forms of selection pressure, some changed within the limits of the norm reaction, and some remained unchanged.
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Correlation coefficients for some dermatoglyphic traits of the Muzeina Bedouins of South Sinai were determined in sib-sib, father-son, father-daughter, mother-son and mother-daughter comparisons. From among approximately 3000 members of the tribe, 60 male sib-sib pairs and 33 parental pairs, each with one son and one daughter, were selected for examination. The dermatoglyphic traits included finger pattern types, ridge counts with their intra-individual variability and bilateral asymmetry, and the incidence of palmar patterns. In such a small, biologically isolated and consanguineous population, the correlation coefficients for the diverse dermatoglyphic traits are expected to show some peculiarities. In general, we found them to be lower than in other populations. The difference is small for the complex traits with a multifactorial genetic determination, and more pronounced for the traits with a simpler genetic base. With diminution in the number of genes participating in the realization of a trait, the father-mother correlations increase owing to the intense consanguinity.
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The relationships between the heterozygosity of the loci of biochemical and morphological traits were compared in seven Jewish populations. This comparison was based, on the one hand, on the average heterozygosity of seven biochemical loci (four blood group and two enzymatic ones) and, on the other hand, on five morphological characters. To assess the heterozygosity level for quantitative traits (normal distribution), we found it useful to measure h = CV mu, where CV is the coefficient of variation, and mu is the deviation of the population mean from the general average divided by the standard deviation of the general distribution. Actually, 'h' represents an inverse measure of the heterozygosity. Marked negative correlation was detected between the biochemical and morphological heterozygosity. This negative correlation was attributed to the convergent influence of inbreeding on different loci, but other possible mechanisms are discussed.
The mutual influence of fingertip pattern types, whorls (W), ulnar loops (Lu), radial loops (Lr) and arches (A), on the pattern ridge count (RC) values is evident from the dermatoglyphics of a sample of 606 Israeli Jewish males. The presence of W is associated with an increase in the RC of Lu and Lr of the same individual, and conversely, the presence of Lu, Lr or A coincides with a decrease in the RC of W. The presence of A decreases also the RC of Lu and Lr, but the reciprocal influence does not occur because the RC of A is, by definition, always equal to zero. When two different pattern types concomitantly affect a third type, the net results is an intermediate one. The modifying influence of a pattern on the RC of others is proportional to the number of fingers carrying that pattern. When the total RC of an individual is used for genetic or medical purposes, the reciprocal influences of fingertip patterns on pattern RC values must be considered.
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The Lewis blood groups, the secretion of ABH antigens and the frequencies of the related genes were determined in some Israeli Jewish populations of different origins. In total 834 individuals were investigated for ABH antigen secretion and of these, 452 for the Lewis antigens. The frequencies of the le gene in the East European, Central European, North African and Middle Eastern groups were 0.3635, 0.3397, 0.3015 and 0.2293, respectively. The frequencies of the se gene in the same groups were 0.4787, 0.4804, 0.5301 and 0.5468. In a South European and a Yemenite Jewish group, studied for the secretor status only, the obtained se gene frequencies were 0.4879 and 0.4663 respectively. Comparing the four groups studied both for Lewis blood groups and for secretor status, the smallest genetic distance was found between the East and Central European groups, and the greatest, between the East European and Middle Eastern groups.
The phosphoglucomutase (PGM1) adenylate kinase (AK1) and acid phosphatase (ACP1) phenotypes were studied in Israeli Jews. In total 934 individuals were investigated for AK1 and of these, 926 for PGM1 and 768 for ACP1 isozymes. From the studied individuals, six groups deriving from Eastern, Central and Southern Europe, the Middle East, North Africa and Yemen were formed. The comparison of the phenotype distribution in these groups by the chi-square test failed to indicate any statistically significant differences with respect to PGM1 phenotypes. With respect to AK1 phenotypes, there were statistically significant differences between the Central European group on the one hand and the Yemenite and South European groups on the other (p less than 0.05), and with respect to ACP1--between the Middle Eastern and the Yemenite groups (p less than 0.01). In the studied groups, the frequency of the PGM11 gene varied from 0.6822 (North African group) to 0.7431 (Central European group), of the AK11 gene--from 0.9099 (Central European group) to 0.9698 (Yemenite group) and of the ACPb1 gene--from 0.6710 (Middle Eastern group) to 0.8194 (Yemenite group). The greatest genetic distances were found between the Yemenite group on the one hand and the Middle Eastern, Central European and East European subgroups on the other.
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Duffy, Kell and P blood group systems were investigated in 977 Israeli Jews. Six groups deriving from Eastern, Central and Southern Europe, the Middle East, North Africa and Yemen were compared. The greatest differences between the groups occurred with regard to the Duffy blood group system, where the Fy gene was found at great frequency (0.5879) in the Yemenite Jews, a middling frequency (from 0.1083 to 0.2191) in Jews from the Middle East, North Africa and Southern Europe, and a low frequency of the Fya gene decreased in the following order: East European greater than Central European greater than South European greater than North African greater than Middle Eastern greater than Yemenite group. The shortest genetic distance was found between the Middle Eastern group on the one hand and the Central European and North African groups on the other. The highest values in the genetic distances were observed between the Yemenite and the other groups. Insofar as the Kell and P gene frequencies are concerned, the compared groups were similar. Comparison of the phenotype distribution by the chi-square test showed statistically significant differences between the groups only with respect to the Duffy system.
A new technique is described for measuring radioactivity in select areas of intact tissue sections. The method, which makes use of a liquid scintillation counter, also makes possible identification of the studied zones by prestaining.
Measurements were made in 50 cadaveric femora and their corresponding tibiae. There was a significant correlation between the femoral and tibial torsion. The clinical and surgical implications of this finding are discussed.
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The ultimate tensile strength, elasticity modulus and ultimate elongation of tail tendon in rats age 1-18 months were measured with an Instron tensile apparatus. An increase in all these parameters was observed during the period of maturation, with a later levelling off of the tensile strength and the ultimate elongation. The value of the elasticity modulus attained a maximum during sexual maturation, and then decreased and stabilized.