Biomedical subjects

G Livshits

Publications and source records attributed to G Livshits.

At least 55 records · Page 3Linked to original sources

PubMed1995

Tel Aviv-Heidelberg three-generation offspring study: genetic determinants of apolipoprotein A1 and apolipoprotein B.

The contribution of major gene and multifactorial effects on variation of plasma apolipoproteins A1 and B has been tested in a large sample of population-based Israeli pedigrees. Our most parsimonious and best fitting model for both apolipoproteins is consistent with Mendelian transmissibility, with significant contribution of major genes (with 2 alleles recessive and dominant within each locus) and polygenes, but neglects effects of common sib environment as well as related intergeneration differences in polygenic effects. Total genetic effects explain 71 and 58% of phenotypic variance of APO-A1 and APO-B levels. The major genes account for about 44 and 32% of the variance in APO-A1 and APO-B, respectively, and the frequency of the recessive alleles determining the high level of apolipoproteins under the study in the Israeli population is in the vicinity of 40% at each locus.

Apolipoprotein A-I↗

PubMed1995

Reliability of reliability coefficients in the estimation of asymmetry.

Although promising to provide insight into the interaction between genotype and environment, investigations into fluctuating asymmetry suffer from a lack of standardization in the reporting of measurement error. In the present paper we show, using both anthropometric and odontometric data, that the use of the reliability coefficient calculated for a bilateral measurement provides no indication of the reliability of the corresponding asymmetry estimate, because reliability of asymmetry depends on the relationship between measurement error and the difference between sides. Thus, we suggest that future investigations either provide reliability coefficients for asymmetry estimates specifically, or use methods that account for measurement error.

Anthropometry↗

PubMed1995

Population biology of human aging: methods of assessment and sex variation.

Biological age, as assessed by osteographic measurements of hand bones from radiograms, was estimated in about 7000 individuals belonging to 32 ethnic groups and samples and to 2 major human groups (Europeans and Asians). Individual ages in the total group varied between 16 and 99 years old. Our biological age measure is strongly correlated with chronological age of the individual (Pearson's r = 0.78-0.80, p < 0.001), which renders the correlation amenable to fitting with a two-stage stochastic model. The following parameters of the model were estimated accordingly: t0 is the minimal age at which initial bone changes occurred, q is the probability that an individual will first develop involutive bone change at age ti > t0, and B is the rate of aging (bone change) per unit time. The parameters varied considerably within different populations, but only a few samples showed statistically significant sex differences for all three parameters. However, B was consistently higher among women than among men. Apart from that, the distributions of the observed biological age estimates adjusted on the expected biological age values reveal no differences between men and women in any of the studied samples or in the total population.

Adolescent↗

PubMed1994

Biology of aging in an Israeli population. 2. Polymorphic blood markers and fluctuating asymmetry.

The major objectives of the present study were to detect whether there are any differences in genetic blood markers distribution between the young and old Israeli population. We also investigated the question about the relationship between the genetic heterozygosity (H) and fluctuating asymmetry (FA) of an individual. The study sample consisted of 208 elderly people aged between 75 and 94 years old. Each individual was assessed for the same 18 anthropological traits, 8 of which were paired bilateral structures and 10 were size and mass measurements. Thirteen polymorphic gene markers were also taken from each individual. Most of the studied gene systems showed no inter-group (old sample vs 207 young individuals) differences. Significant differences were detected at ADA, ESD, GTP1 and FY loci. These differences were mainly due for the considerably lower frequency of the heterozygous individuals in elderly samples. Our working hypothesis at the next stage of the analysis were as follows: 1. Morphologically central phenotypes are more symmetric (processes lower FA) than morphologically extreme individuals. 2. There is a detectable negative correlation between the FA and individuals H. To study these questions we developed a multivariate measure of FA and morphological deviation of the individual from the population centroid. Yet, no reliable evidence in support of either of the two hypotheses were obtained.

Adult↗

PubMed1994

Ethnic differences in indices of body mass and body fat distribution in Israel.

Ethnic differences in cardiovascular disease have been demonstrated in the Jewish population in Israel. Different measures of body fat have been shown to be directly and indirectly associated with increased risk of cardiovascular disease. It is not known to what extent lifestyle and genetic factors contribute to the distribution of body fat. The aim of this study was to examine ethnic differences in the distribution of body fat among Israelis. Between 1985 and 1989, a sample of 2154 males and 1395 females employed in Israeli industry were screened for selected risk factors for cardiovascular disease, in the framework of the Israel CORDIS study. Anthropometric measurements included height, weight, three circumferences (waist, hip, chest) and two skinfolds (subscapular and triceps skinfolds). In univariate analysis of six anthropometric variables, highly significant differences (P < 0.001) between ethnic groups were found in both sexes. The subjects of European origin had the highest amount of fat in the upper part of the body (WHR) for both sexes. After adjustment for factors such as cigarette smoking, education and sporting activity, the discrimination between ethnic groups remained statistically significant (P < 0.001) for all anthropometric indices except the triceps skinfold. Body mass index was not the best discriminating variable. Chest-to-waist ratio was the most powerful discriminator in males, but the subscapular-to-triceps ratio was the most powerful in females. These findings suggest that differences in body fat distribution are derived from both genetic and lifestyle factors.

Adipose Tissue↗

PubMed1993

Geographic variation of six dermatoglyphic traits in Eurasia.

We describe the geographic variation patterns of six dermatoglyphic traits from 144 samples in Eurasia. The methods of analysis include computation of interpolated surfaces, one-dimensional and directional correlograms, correlations between all pairs of surfaces, and distances between correlograms. There are at least two, probably three, distinct and significant patterns of variation. 1) A general NW-SE trend for pattern intensity, the main line index, and frequency of hypothenar patterns. 2) A trend from the Middle East to the north and east for frequency of axial triradius and of accessory interdigital triradii. 3) A patchy pattern for frequency of the thenar-interdigital 1. The results are compatible with a diffusion process between Europe and the peoples of Northern Asia, and possibly with a radiation of populations from the Middle East. The hypothesis of diffusion processes is supported by substantial interpopulation correlations between dermatoglyphic traits that contrast sharply with largely negligible intralocality correlations.

Asia↗

PubMed1993

Variables affecting dental fluctuating asymmetry in human isolates.

The aims of the present study are to 1) determine and describe levels of dental fluctuating asymmetry (FA) in a highly endogamous human group; 2) evaluate the effects of various FA measures on perceived FA levels and their interrelationships; 3) study the connections between dental variables (tooth size, class, position, type, location and dimension) and FA levels; and 4) estimate the interrelationships between dental FA measures. The study was carried out on 242 Bedouin boys aged 5 to 14 years. The results demonstrate that the main variables influencing dental FA levels within this population are tooth class (incisors, canine, premolars, molars) and position (mesial, distal) and that the interaction between the two is significant. When sample sizes are large enough and individual measures are needed for the statistical analysis, the use of a computational method based on absolute values is legitimate. Clear relationships between some FA dental traits are discerned through principal-components analysis.

Child↗

PubMed1993

Soluble tumour necrosis factor receptors (sTNF-R) and HIV infection: correlation to CD8+ lymphocytes.

The objective of this study was to determine sTNF-R, type I (p55) and type II (p75) in sera of HIV-infected male homosexuals and correlate them to T lymphocyte subpopulations and course of HIV infection. Serum samples were obtained from 39 HIV-1+ asymptomatic male homosexuals, 10 symptomatic (ARC and AIDS) male homosexuals and 44 HIV- non-homosexual healthy controls. sTNF-R levels were determined by ELISA with specific MoAbs and polyclonal antibodies to the sTNF-R proteins. sTNF-RI and II levels were significantly elevated in 72% and 74% respectively of HIV+ asymptomatic male homosexuals and in all of the symptomatic male homosexuals. In sequential studies a highly significant positive correlation was found between sTNF-RI and sTNF-RII (r = 0.8, P < 0.001) and between both sTNF-R and CD8+ lymphocyte counts (r = 0.6 and 0.92, respectively, P < 0.01-0.001) during the asymptomatic stage of the infection. All these correlations were lost, however, during the symptomatic phase of the disease. These results suggest that: (i) HIV infection is associated with elevation of sTNF-R serum levels; (ii) sTNF-R levels are strongly correlated to CD8+ lymphocytes during the asymptomatic stage of HIV infection.

Adult↗

PubMed1993

Biology of aging in an Israeli population. 1. Review of literature and morphological variation analysis.

This article reports the results of a comparative morphological assessment carried out on five age segments of an Israeli population: 1. neonates, 2. early school age children (6.5-7.5 years old), 3. young adults (18-29), 4. mature adults (30-45) and 5. elderly people (75-94). The aim of the investigation was to analyze the relationship between developmental homeostasis phenomena and the aging process. Developmental homeostasis was assessed via group coefficient of variation (CV) for 21 morphological traits and fluctuating asymmetry (FA) for 8 bilateral traits. The majority of traits was found to show significantly increased CV and FA in the elderly group. This finding is consistent with the hypothesis that the aging process is accompanied by the total breakdown of the individual's developmental stability.

Adolescent↗

PubMed1993

Multivariate fluctuating asymmetry in Israeli adults.

Fluctuating asymmetry serves as an indicator of developmental homeostasis; any genetic or environmental factor that destroys homeostasis disturbs bilateral symmetry. Many studies have attempted to correlate increased fluctuating asymmetry with measures of developmental homeostasis or of adaptation, but collective results have been equivocal. We still have much to learn about fluctuating asymmetry itself. We develop a multivariate treatment of bilateral asymmetry that allows us to measure and adjust for the effects of both directional (right versus left) asymmetry and antisymmetry (handedness) and for the effects of size and sex. We examine 29 morphometric traits (13 size and shape, 8 pairs of bilateral traits) on 400 Israeli adults. We show that, even if metric traits are logarithmically transformed at the outset so that nonlinear allometric relations among them are properly accounted for and if the resulting measures are adjusted for sex by subtracting the means and dividing by the standard deviations, the correlation matrices among traits are strongly heterogeneous across sexes. Although the bilateral traits as a set are modestly correlated with the size and shape traits, neither size nor shape is correlated with asymmetry. Moreover, asymmetry traits are virtually uncorrelated inter se. We also examine the often touted connection between asymmetry and departures from morphometric modality and show that asymmetry is not correlated with deviations from either average size or average shape. If properly measured, fluctuating asymmetry becomes a measure of the noise in development; in our study it correlates with nothing. We discuss these results in light of empirical results and in terms of developmental theory suggesting that fluctuating asymmetry should be correlated with measures of maladaptation. Some of the effects reported in the literature need to be reexamined with more refined morphometric and statistical techniques.

Adult↗

PubMed1991

Fluctuating asymmetry as a possible measure of developmental homeostasis in humans: a review.

We investigate three hypotheses related to fluctuating asymmetry (FA) of bilateral morphologic traits in humans: (1) the magnitude of FA in individual suffering from different levels of morbidity is significantly elevated compared with FA in healthy control subjects, (2) FA is negatively correlated with an individual's heterozygosity, and (3) phenotypic variance of FA may have a significant genetic component (or at least a family resemblance). Our experimental data and the literature support the first hypothesis and indicate that individuals who suffer from chromosomal or polygenic morbidity and from anomalies or conditions of development with still unknown genetic components demonstrate an elevated FA of various structures. The literature regarding the second hypothesis is sparse but is generally in agreement with it, although some exceptions exist. A study of correlations of phenotypic scores of FA between family members of nuclear families in two independent samples has shown that FA variance in individual traits probably does not have any significant genetic component. However, phenotypic variance of the mean estimate of FA over 8 traits showed significant additive and nonadditive (dominance) genetic components, each about 0.30.

Anthropometry↗

PubMed1991

Genetic affinities of Jewish populations.

Genetic relations between various Jewish (J) and non-Jewish (NJ) populations were assessed using two sets of data. The first set contained 12 pairs of matched J and NJ populations from Europe, the Middle East, and North Africa, for which 10 common polymorphic genetic systems (13 loci) were available. The second set included 22 polymorphic genetic systems (26 loci) with various numbers of populations (ranging from 21 to 51) for each system. Therefore, each system was studied separately. Nei's standard genetic distance (D) matrices obtained for these two sets of data were tested against design matrices specifying hypotheses concerning the affiliations of the tested populations. The tests against single designs were carried out by means of Mantel tests. Our results consistently show lower distances among J populations than with their NJ neighbors, most simply explained by the common origin of the former. Yet, there is evidence also of genetic similarity between J and corresponding NJ populations, suggesting reciprocal gene flow between these populations or convergent selection in a common environment. The results of our study also indicate that stochastic factors are likely to have played a role in masking the descent relationships of the J populations.

Gene Frequency↗

PubMed1990

The relative contribution of birth weight and gestational age to physical traits of newborn infants.

The present study establishes anthropometric standards for newborn infants, born between 26-41 weeks of gestational age. The measurement of 10 standard anthropometric traits was made within the first 72 hours of life in 224 preterm (26-36 weeks) and 190 term (37-41 weeks) infants. Multiple regression analysis was carried out for each of these anthropometric traits (dependent variables) on gestational age, birth weight and sex (independent variables). It was found that the prediction of several traits, namely, body length, body mass index, body surface area, interocular diameter, ear length and palm length, can be done solely via the information on birth weight; cephalic index is better predicted on the basis of gestational age, while for the prediction of such cranial traits as the circumference, length and breadth of head, both birth weight and gestational age are desirable.

Birth Weight↗

PubMed1989

Multivariate analysis of the twenty-year follow-up of the Donolo-Tel Aviv Prospective Coronary Artery Disease Study and the usefulness of high density lipoprotein cholesterol percentage.

The aim of this study was to assess the role of high density lipoprotein (HDL)-cholesterol percentage and its relation to other variables assumed to be coronary risk factors. The 20-year follow-up involved 2,633 presumably healthy subjects, 1,308 men and 1,325 women, aged 25 to 69 years at the beginning of the study in 1964. Variables determined at entry examination included total cholesterol, HDL cholesterol, systolic and diastolic blood pressures, body mass index and cigarette smoking. During the 20-year period there were 242 fatal and nonfatal definite coronary events in men, and 108 in women. All variables differed in varying degrees between subjects who did and did not have a definite coronary event. Three multiple logistic regression models revealed that among these variables the most important was HDL-cholesterol percentage, which significantly improved the regression, even after total cholesterol was included with all other risk factors. With the first model, goodness-of-fit tests indicated that predicted values fit the observed values well, even after the first step, if HDL-cholesterol percentage is entered. The second and third models significantly fit the predicted values only after entering the HDL-cholesterol percentages. This means that although all the other variables, including total cholesterol, differed significantly between the affected and nonaffected groups, they were insufficient predictors alone. The results reveal that HDL-cholesterol percentage had the highest predictive value for risk of future coronary disease; it significantly improved the predictive capability of the logistic regression model, even after adjustment for all other mentioned variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Genetic relationships of Europeans, Asians and Africans and the origin of modern Homo sapiens.

To study the evolutionary relationships of the three major groups of humans, Europeans, Asians and Africans, the genetic distances between them were computed by using 4 different sets of genetic loci (84 protein loci, 33 blood group loci, 8 HLA and immunoglobulin loci, and 61 DNA markers). The results obtained indicate that the overall genetic distance between Europeans and Asians is significantly lower than that between Europeans and Africans of that between Asians and Africans and support the hypothesis of an African origin of modern humans. This seems to be the first study to establish the evolutionary relationships of the three major groups of humans at a statistically significant level.

Africa↗

PubMed1989

Ethnic and family factors of some common diseases in early childhood.

The primary purpose of the present study was to examine the comparative incidence of some common diseases with unknown genetic components (e.g. newborn jaundice, urinary and respiratory tract infections) in infants of Israeli families of mixed and non-mixed ethnic origin. We also studied possible relationships between risk of these diseases and a number of anthropometric and demographic factors. Only the group of infants whose parents originated from North Africa and Middle East showed statistically significant differences: namely an increased level of total morbidity, of various comparisons of specific disease frequencies, and in total illness frequency, between infants from "mixed" and "non-mixed" families. In general, however, there was a positive correlation between frequency of healthy infants in "mixed" group and genetic distance between parents. Our findings also indicated a significant association between weight and head circumference of newborn infants respectively, and their illnesses, especially jaundice.

Africa, Northern↗

PubMed1988

Decreased developmental stability as assessed by fluctuating asymmetry of morphometric traits in preterm infants.

Fluctuating asymmetry (FA) of 8 morphometric traits was studied in 113 preterm infants (26-36 wk of gestation), 103 term infants (37-41 wk), and their respective parents. With 3 different measures of FA, the highest values were obtained from extremely preterm infants (26-29 wk), and the lowest from the group of term infants. The estimates of FA values among parents, particularly mothers, showed a similar, albeit less pronounced, trend. Multiple regression analysis of individual mean FA values, calculated in infants for the 8 studied bilateral traits, documented a significant inverse correlation with gestational age and with the health status of the infants and their mothers, as well as a positive correlation with the mothers' mean FA values.

Anthropometry↗

PubMed1988

Some biological and social factors of risk associated with the birth of pre-term infants.

The main purpose of the present study was to evaluate the effects of factors associated with spontaneous pre-term births so that the high risk woman could be identified before or at early stages of pregnancy. For this purpose, we have compared the measurements of 21 anthropometric traits and mean fluctuating asymmetry over 8 bilateral anthropometric traits, as well as age, occupation, education, previous obstetric history, complications during pregnancy, medicines received during and after pregnancy and some others in women who delivered babies of short (26-36 wk, n = 113 ind.) and normal gestational age (n = 103). Diseases and mean fluctuating asymmetry of eight morphological traits in the newborn infants themselves were also studied. Both univariate and multivariate analyses were carried out and these were in agreement, showing a highly significant increase in the morbidity rate (especially of respiratory diseases) among pre-term infants and in complications during pregnancy in their mothers. Among other variables associated with the current pre-term birth were previous spontaneous pre-term births, suggesting their special risk value. The estimate of the sib correlation in gestational age on the liability scale was about 0.63. Spearman and Pearson correlations in gestational age for siblings were 0.34 and 0.31, respectively.

Female↗