Genetic analysis of human obesity in an Italian sample.

An analysis of the genetic factors in obesity has been carried out on a sample of nuclear families from Aosta (N. Italy). The families consisted of the parents and sibs of all elementary school children considered to be obese during a preliminary screening and a similar sample of non-obese children and their nuclear families. The numbers of such families were 67 and 112, respectively. Several tests were applied in order to examine the genetic contribution to obesity, and in particular to investigate the presence of a dominant major gene. Our conclusions are that genetic factors are certainly present. Several analyses suggest the presence of a dominant major gene with weak effect.

A morphotypological analysis of an Italian population: association with obesity.

The morphotypological method of Brian (1960) was applied to the data collected in Aosta (N. Italy) during an investigation on human obesity. The data consist of anthropometric measurements on members of families ascertained by the presence of obesity in the children and therefore the frequency of obesity is much higher than in the general population. One of the morphotypes was found only among the obese and two others were much more common among the obese than among the non-obese. More than 80% of the obese (vs. 10% of the non-obese) belonged to these three classes. There was a positive parent-offspring association for two of the components of the morphotype (morphy and somy).

A nonparametric and a parametric version of a test for the detection of the presence of a major gene applicable on data for the complete nuclear family.

Nonparametric and parametric tests are suggested for detecting the presence of a major gene for a quantitative trait. The model for the determination of the quantitative trait is an additive one with polygenic, family environment, and individual environment components. The power functions with respect to the major gene effect have been calculated by simulation, and the tests have therefore been compared with each other. The tests have been applied to nuclear family data on human obesity, and the results compared with those obtained using other methods on the same data.

Multivariate statistical analysis of quantitative serum protein data in populations of Rwanda.

Data on serum protein levels of four populations from Rwanda were analyzed by multivariate statistical methods to assess their utility as an anthropological tool. These populations consisted of two ethnic groups in two different environments. Seven proteins were considered in the analysis. The total concentration of proteins is intermediate between Italian levels and those of the Binga pygmies of the Republic of Central Africa (RCA). Discrimination between the populations was possible with a 25% misclassification. The major principal components can be interpreted from a medical viewpoint, and show significant differences between the populations.

Coevolution of species in competition: a theoretical study.

A model is presented for the coevolution of several species in competition, each species being genetically variable at one locus with respect to this competition. A function was fund that is maximized during coevolution. This maximization principle was used in order to study the result of competition for a single resource on the utilization functions of the species competing for that resource. In particular, the conditions under which ecological character displacement can evolve were examined.

A new improved clinical staging system for multiple myeloma based on analysis of 123 treated patients.

The effect of the presenting clinical features on survival time was evaluated in 173 patients of a population of 201 individuals with multiple myeloma observed at Malmö General Hospital during the 11-yr period 1960 to January 1, 1971. Complete follow-up was continued until December 1978. One-hundred and five of the patients came from the city of Malmö and constitute a complete nonselected myeloma population. Bivariate correlation and multivariate regression analyses showed that the survival (i.e., the prognosis) could be accurately predicted in IgG and pure Bence Jones myeloma patients from (A) serum creatinine level, (B) serum calcium level, and (C) bone marrow plasma cell percentage; and in IgA myeloma patients from (A) hemoglobin level, (B) serum calcium level, and (C) serum M-component level. The results were synthesized to produce a simple and reliable clinical staging system with three stages (i.e., risks of death). To facilitate the clinical application, multivariate regression equations were developed to optimally predict the prognosis, and graphs were constructed in order to make the staging of the myeloma patients easier and quicker. The comparison of the duration of survival between the three groups of staged patients confirmed the high reliability of the present staging system.

High incidence and heterogeneity of functional defects of the alternative pathway of complement among atopic children.

Two separate functional defects of the alternate pathway of complement (defective yeast opsonisation and defective rabbit erythrocyte lysis) are very frequent (of the order of 55% for the former and 35% for the latter) among atopic children and their unaffected relatives. The defects are independent of each other and of sex, age, season of sampling, type of atopic syndrome and IgE level. The alternative pathway initiation mechanism is probably involved in both defects.

Parasite-reactive serum IgE antibodies in African populations. Relation to intestinal parasite load.

Serum IgE levels and IgE antibodies against four intestinal parasites, and the presence and abundance of parasites in stool samples were investigated in 161 Rwanda natives. Most of the IgE turn out to be helminth-reacting antibodies. The stimulation and production of these antibodies are much different from those of anti-amoeba antibodies in their relation to the specific intestinal parasite load; helminth infestations seem to play a major role in the development of anti-amoeba antibodies as well.

Relationship between serum IgE levels and intestinal parasite load in African populations.

Serum IgE determinations and coproparasitological analyses were carried out on 161 individuals from two distinct ethnic groups (Hutus and Twas) from two regions in Rwanda (North and South). The cumulative parasitosis index (calculated for each individual as the sum of the scores for the four most frequent intestinal parasites) show a linear relation with IgE levels up to a plateau, with no clear pattern of correlation between the score for any given parasite and the IgE level. Such a direct quantitative (but not qualitative) relation reproposes the question on the role of IgE immunoglobulins in intestinal parasitoses.

The use of discriminant analysis to define obesity in children aged 7-11 years.

All the elementary schoolchildren (ages 7-11 years) in the city of Aosta were diagnosed clinically for obesity and measured for height, weight and triceps and subscapular skinfolds. A statistical discriminant analysis revealed that, on the basis of these measurements, this population of children could be divided into a group of normal children and one or more distinct populations of obese children. To the extent that these groups reveal qualitative phenotypic differences, they should simplify genetic studies of obesity.

Serum protein levels as anthropological markers: a statistical analysis in Binga Pygmies and Italians.

Data on serum protein levels in Binga Pygmies are presented, and these are compared with the levels in healthy Italians and in Italians suffering from liver diseases. Principal Component Analysis carried out on the three groups points out similarities in protein levels between the Pygmies and the Italian Hepatopaths on one hand and between healthy and liver diseased Italians on the other. Discriminant Analyses reveal the important differences between the populations. It is suggested that such analyses of protein levels could serve as tools in population biology.

Immunodeficiency in Down's syndrome: relationship between presence of human thyroglobulin antibodies and HBsAg carrier status.

The relationship between the presence of hepatitis B surface antigen (HBsAg) and antibodies to human thyroglobulin (HTgAb) has been studied in 110 subjects with Down's syndrome (DS) from 4 months to 50 years of age and in 122 controls carefully matched for sex, age and socio-environmental conditions. The overall percentage of HBsAg carriers was 22.7 in DS and 6.6 in controls and that of HTgAb-positive subjects was 41.8 in DS and 19.7 in controls. In DS the frequency of HTgAb-positive subjects was very high, even in the youngest age groups in which the percentage of HBsAg carriers was relatively low; the latter thereafter showed a marked increase with age. A positive association between the presence of HBsAg and HTgAb was found only in the oldest age group of DS subjects. It is thus concluded that in DS the high frequency of HTgAb cannot be attributed to chronic hepatitis B virus infection. On the contrary, the presence of HTgAb might well represent an early "marker" of immunodeficiency and increased susceptibility to infection with hepatitis B virus.