Analysing body composition as compositional data: An exploration of the relationship between body composition, body mass and bone strength.

Human body composition is made up of mutually exclusive and exhaustive parts (e.g. %truncal fat, %non-truncal fat and %fat-free mass) which are constrained to sum to the same total (100%). In statistical analyses, individual parts of body composition (e.g. %truncal fat or %fat-free mass) have traditionally been used as proxies for body composition, and have been linked with a range of health outcomes. But analysis of individual parts omits information about the other parts, which are intrinsically co-dependent because of the constant sum constraint of 100%. Further, body mass may be associated with health outcomes. We describe a statistical approach for body composition based on compositional data analysis. The body composition data are expressed as logratios to allow relative information about all the compositional parts to be explored simultaneously in relation to health outcomes. We describe a recent extension to the logratio approach to compositional data analysis which allows absolute information about the total of the compositional parts (body mass) to be considered alongside relative information about body composition. The statistical approach is illustrated by an example that explores the relationships between adults' body composition, body mass and bone strength.

Allergies in immigrants.

We studied the influence of environmental factors on allergy disease in immigrants that came to Israel during the last 20 years from A) Ethiopia and B) former Soviet Union. Immigrants who came from Ethiopia had no allergies upon arrival; they suffered from severe parasitic infections and had extremely elevated IgE levels. They got thorough anti parasitic treatment and were gradually integrated in the old timer Israeli population. After 5-10 years from arrival, follow up assessments showed a significant drop in IgE levels while respiratory allergies with positive skin tests Respiratory allergies with positive skin tests) to aero allergens appeared at a prevalence of 11%. Israeli born newborns and children from Ethiopian descent had no stool parasites and their total IgE levels were similar to those of the indigenous population. Immigrants from former Soviet Union who had respiratory allergies upon arrival, showed skin tested hypersensitivity to pollen common in their Russian, homelands while they were not sensitive to the Mediterranean pollen common in Israel. At yearly follow up testing over the first 10 years in Israel, odds for sensitization to Russian pollen decreased while odds for sensitization to Israeli pollen increased significantly. The results of our studies plead the case for the very important role played by the environment in the dynamics of allergy diseases.

Hepatic infarctions during pregnancy are associated with the antiphospholipid syndrome and in addition with complete or incomplete HELLP syndrome.

Antiphospholipid antibody syndrome (APS) is associated with adverse pregnancy outcomes and maternal complications including thrombotic events and early pre-eclampsia. HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelets) represents a unique form in the spectrum of pre-eclampsia. This report describes four patients with pregnancy-associated hepatic infarctions. All four had APS and HELLP syndrome, which was complete in one patient and incomplete in three patients, with elevated liver enzymes in all, and either thrombocytopenia or hemolysis in two. In the literature, we found descriptions of an additional 24 patients who had 26 pregnancies with concomitant hepatic infarction. Of the total 28 patients, anticardiolipin antibodies (aCL) and/or lupus anticoagulant (LAC) were assessed in 16 patients, out of whom 15 were found to be positive. Hepatic infartction during pregnancy was associated almost always with APS, with HELLP (2/3 complete, 1/3 incomplete), and only in one-third of the pregnancies with pre-eclampsia (PE).

Does skin prick test correlate with basophil-associated mite-specific IgE in atopic children?

Skin prick test (SPT), as the standard diagnostic tool for immediate hypersensitivity to aeroallergens, is an expression of IgE-dependent mediator release from dermal mast cells. Though probably involved in the late-phase response, peripheral blood basophils (PBB) don't seem to participate in the immediate hypersensitivity response in the skin. We aimed to assess a possible correlation between the SPT to mites and levels of basophil-associated mite-specific IgE. We sequentially enrolled 15 children with allergic rhinitis and documented class > II mite sensitization, mean age 13 years (range 9.5-18), 11 males, 4 females. Symptoms score was determined using a validated questioner. SPT area under the curve (AUC) for 10 common respiratory allergens was measured in all patients. Heparinized blood after basophil enrichment, was lysed with CHAPS. Determination of allergen-specific and total IgE in serum and cell lysate supernatant was performed using standard commercial kits. Basophil-associated, mite-specific IgE could be reliably determined only in 10 patients with a skin reaction greater than 70 mm2, OR 36 (95% CI 1.8-732, p = 0.02). We found a strong linear correlation (R2 = 0.74, p = 0.001) between mite-specific basophil-associated IgE density (IgE molecules per cell) and the SPT AUC. This finding suggests that skin mast cell precursors and basophil both bind specific IgE at a common site prior to the arrival of mast cells to the skin.

Low molecular weight heparin and warfarin in the treatment of patients with antiphospholipid syndrome during pregnancy.

Fifty-seven pregnancies in women with antiphospholipid syndrome (APS) are presented. These were treated with s.c. enoxaparin and low dose aspirin. In fourteen pregnancies warfarin was prescribed between weeks 15-34 (warfarin group). The decision to switch to warfarin depended on a morbidity score, and the patient's consent. Neither teratogenicity nor significant maternal, fetal or neonatal hemorrhage was observed. Despite the higher pretreatment morbidity score of the warfarin group, the live birth rate was high in both groups: 86% in the warfarin group and 87% in the non-warfarin group. There was no significant difference in week of delivery, birth weight, or incidence of thrombosis between the groups. The study demonstrates the efficacy and safety of anticoagulants during pregnancy. The use of LMWH in pregnant women with APS not being moot, warfarin might be justified in selected patients.

Improve performance by appraisal.

An effective performance appraisal system will not only evaluate employees' ability and motivation, but also opportunity--those elements in the work system which contribute to performance. The authors explain how this approach works.

IgA, IgG, IgM, and IgE levels in normal, healthy, non-atopic Israeli children.

IgA, IgG, IgM, and IgE levels in healthy, non-atopic, Israeli-born children aged 20 days to 16 years were analyzed and showed similar age-related values and dynamics as those of white populations found in other countries. No significant effect of sex of the individual or ethnic origin of the parents was found on the IgE values at different ages. This may indicate that total IgE levels are strongly influenced by environmental factors. Establishing tolerance limits at 97.5, 95, 75, 25 and 5th percentiles and the geometric mean provides the practitioner with more complete reference values. The use of multivariate control charts with tolerance limits from normal IgA, IgG, IgM, and IgE levels is described and is offered as an additional tool for the diagnosis of an allergic individual.

Atopic babies with wheezy bronchitis. Follow-up study relating prognosis to sequential IgE values, type of early infant feeding, exposure to parental smoking and incidence of lower respiratory tract infections.

Clinical course and sequential IgE values were recorded in a 4-year prospective study of 80 atopic wheezing babies at ages from 6 months to 4-5 years. At final assessment, 68% of the children had been symptom-free for at least 1 year whilst 32% still suffered from wheezing attacks. Total IgE levels from the first visit until final assessment were greater than 2 SD above normal for age in 63% of all children, but no significant correlation could be found between sequential IgE levels and the clinical picture or course of the disease. In all cases IgE levels rose steadily with increasing age, independently of whether wheezing disappeared or persisted. The most significant rise in IgE values occurred between 1 and 2 years of age, and IgE levels at 4 years could be predicted by the value at the age of 2 years (r = 0.97). In the group of children that lost their wheezing tendency there was: a significantly greater number of infants that were breast-fed during at least the first 3 months of life (P less than 0.01), a lower incidence of exposure to parental smoking (P less than 0.01), and a lesser incidence of lower respiratory tract infections (P less than 0.01). Though there was no correlation between increase of IgE levels and type of feeding or exposure to cigarette smoke, statistical data confirms that bottle feeding and parental smoking lead to persistence of wheezing in atopic children.

Survey of immunoglobulin E levels in atopic families in Israel.

Two hundred and ten members belonging to two consecutive generations of 41 atopic families (healthy and affected by clinical atopic manifestations) were investigated for basal immunoglobulin E (IgE) levels and clinical picture. The results show overall increased IgE levels, above standard values in the whole population studied, and a significant correlation between clinical atopy and high IgE levels in the children of the group. Within these families recessive inheritance of abnormally high IgE levels suggests that their high IgE levels are due to a genetically transmitted defect in IgE suppression.

Analysis of genetic data on Jewish populations. I. Historical background, demographic features, and genetic markers.

Part I describes the data sets on which the analysis of Part II is based. This covers the nature of the populations sampled, the extent to which the samples are representative, and a brief review of historical and demographic facts on the populations involved.

Analysis of biochemical genetic data on Jewish populations: II. Results and interpretations of heterogeneity indices and distance measures with respect to standards.

A nonparametric statistical methodology is used for the analysis of biochemical frequency data observed on a series of nine Jewish and six non-Jewish populations. Two categories of statistics are used: heterogeneity indices and various distance measures with respect to a standard. The latter are more discriminating in exploiting historical, geographical and culturally relevant information. A number of partial orderings and distance relationships among the populations are determined. Our concern in this study is to analyze similarities and differences among the Jewish populations, in terms of the gene frequency distributions for a number of genetic markers. Typical questions discussed are as follows: These Jewish populations differ in certain morphological and anthropometric traits. Are there corresponding differences in biochemical genetic constitution? How can we assess the extent of heterogeneity between and within groupings? Which class of markers (blood typings or protein loci) discriminates better among the separate populations? The results are quite surprising. For example, we found the Ashkenazi, Sephardi and Iraqi Jewish populations to be consistently close in genetic constitution and distant from all the other populations, namely the Yemenite and Cochin Jews, the Arabs, and the non-Jewish German and Russian populations. We found the Polish Jewish community the most heterogeneous among all Jewish populations. The blood loci discriminate better than the protein loci. A number of possible interpretations and hypotheses for these and other results are offered. The method devised for this analysis should prove useful in studying similarities and differences for other groups of populations for which substantial biochemical polymorphic data are available.