Reproducibility and within-day variability of body fat measurements using segmental bipolar bioelectrical impedance in women

BACKGROUND AND AIMS: little is known regarding the reproducibility of body fat measuring devices; hence, we assessed the between and within-device reproducibility, and the within-day variability of body fat measurements. METHODS: body fat percentage was measured twice on seventeen female students aged between 18 and 20 with a body mass index of 21.9 ± 2.5 kg/m2 (mean ± SD) using seven bipolar bioelectrical impedance devices. Each participant was also measured each hour between 7:00 and 22:00. RESULTS: the correlation between first and second measurements was very high (Spearman r between 0.985 and 1.000, p<0.001), as well as between devices (Spearman r between 0.916 and 0.991, p<0.001). Repeated measurements analysis showed no differences were between devices (p=0.59) or readings (first vs. second: p=0.74). Conversely, significant differences were found between assessment periods throughout the day, measurements made in the morning being lower than those made in the afternoon (F test for repeated values= 6.58, p<0.001). CONCLUSIONS: the between and within-device reproducibility for measuring body fat is high, enabling the use of multiple devices in a single study. Conversely, small but significant changes in body fat measurements occur during the day, urging body fat measurements to be performed at fixed times.

Prevalence of the metabolic syndrome in the Seychelles according to different definitions, contribution of components, and agreement between different definitions

Background: The metabolic syndrome (MS) represents a cluster of metabolic disorders that predicts diabetes and cardiovascular disease. Several definitions exist and further descriptive and prospective data are needed to compare these definitions and their significance in different populations. Objective: We examined, in a country of the African region, i) the prevalence of MS according to three major definitions (ATP, IDF, WHO); ii) the contribution of individual MS components; and iii) the agreement between the three considered definitions. We also examined the prevalence among diabetics and non-diabetics. Methods: We conducted an examination survey in a sample representative of the general population aged 25-64 of the Seychelles (Indian Ocean, African region), attended by 1255 persons (participation rate of 80.2%). Results: The prevalence of MS was similar with either definition of MS in men (24%-25%) but differed in women (WHO: 25%, ATP: 32%; IDF: 35%). Upon exclusion of diabetic persons, the prevalence was 5-10% lower for all three MS definitions: most diabetic persons had MS although a substantial proportion of diabetic men aged 45-64 did not have MS. The following components were found most often among persons with MS: 90% had high blood pressure (HBP) and 78% had obesity (ATP); 95% had obesity and 84% had HBP (WHO), and 89% had HBP and 75% had impaired glucose regulation (IDF) -not considering impaired glucose regulation and obesity that are compulsory components of the WHO and IDF definitions, respectively. Among persons with MS based on either of the three definitions (37% of total population), less than 80% met both ATP and IDF criteria, 67% both WHO and IDF criteria, 54% both WHO and ATP criteria and only 37% met all three definitions. Conclusions. We found a fairly high prevalence of MS in an African population. However, because there was only poor agreement between the 3 MS definitions, the fairly similar proportions of MS based on ATP, IDF or WHO definitions identified, to a substantial extent, different subjects as having MS.

Basal and antigen-induced exposure of the proline-rich sequence in CD3ε.

The CD3ε cytoplasmic tail contains a conserved proline-rich sequence (PRS) that influences TCR-CD3 expression and signaling. Although the PRS can bind the SH3.1 domain of the cytosolic adapter Nck, whether the PRS is constitutively available for Nck binding or instead represents a cryptic motif that is exposed via conformational change upon TCR-CD3 engagement (CD3Δc) is currently unresolved. Furthermore, the extent to which a cis-acting CD3ε basic amino acid-rich stretch (BRS), with its unique phosphoinositide-binding capability, might impact PRS accessibility is not clear. In this study, we found that freshly harvested primary thymocytes expressed low to moderate basal levels of Nck-accessible PRS ("open-CD3"), although most TCR-CD3 complexes were inaccessible to Nck ("closed-CD3"). Ag presentation in vivo induced open-CD3, accounting for half of the basal level found in thymocytes from MHC(+) mice. Additional stimulation with either anti-CD3 Abs or peptide-MHC ligands further elevated open-CD3 above basal levels, consistent with a model wherein antigenic engagement induces maximum PRS exposure. We also found that the open-CD3 conformation induced by APCs outlasted the time of ligand occupancy, marking receptors that had been engaged. Finally, CD3ε BRS-phosphoinositide interactions played no role in either adoption of the initial closed-CD3 conformation or induction of open-CD3 by Ab stimulation. Thus, a basal level of open-CD3 is succeeded by a higher, induced level upon TCR-CD3 engagement, involving CD3Δc and prolonged accessibility of the CD3ε PRS to Nck.

Socioeconomic gradients in mortality in the oldest old: a review.

This review aims at identifying gaps in knowledge on socioeconomic gradients in mortality in the oldest old. The authors review literature on oldest old population with a focus on unanswered questions: do socioeconomic status (SES) gradients in mortality persist after 80; does the magnitude of the gradient change as compared with younger populations; which socioeconomic/socio-demographic determinants should be used in this population with specific characteristics (e.g., with respect to sex ratio and household type)? Results are often inconsistent while conclusions drawn by selected studies are generally limited by the difficulty of disentangling the effects of age and cohort, and of generalizing results observed in preponderantly small, selected samples (which typically exclude institutionalized persons). Future research should explore the effects of socio-demographic indicators other than education and social class (e.g., marital status, loss of the partner) and adequately differentiate the social position of oldest old women. The authors recommend that research applies a life-course perspective combined with an interdisciplinary perspective to improve our understanding of the SES gradients in later life. Research is needed to elucidate which causal pathways depending on SES in younger age impact on mortality in higher ages up to oldest old.

Identification of the Boudicca and Sinbad retrotransposons in the genome of the human blood fluke Schistosoma haematobium

Schistosomes have a comparatively large genome, estimated for Schistosoma mansoni to be about 270 megabase pairs (haploid genome). Recent findings have shown that mobile genetic elements constitute significant proportions of the genomes of S. mansoni and S. japonicum. Much less information is available on the genome of the third major human schistosome, S. haematobium. In order to investigate the possible evolutionary origins of the S. mansoni long terminal repeat retrotransposons Boudicca and Sinbad, several genomes were searched by Southern blot for the presence of these retrotransposons. These included three species of schistosomes, S. mansoni, S. japonicum, and S. haematobium, and three related platyhelminth genomes, the liver flukes Fasciola hepatica and Fascioloides magna and the planarian, Dugesia dorotocephala. In addition, Homo sapiens and three snail host genomes, Biomphalaria glabrata, Oncomelania hupensis, and Bulinus truncatus, were examined for possible indications of a horizontal origin for these retrotransposons. Southern hybridization analysis indicated that both Boudicca and Sinbad were present in the genome of S. haematobium. Furthermore, low stringency Southern hybridization analyses suggested that a Boudicca-like retrotransposon was present in the genome of B. truncatus, the snail host of S. haematobium.

Is accurate perception of body image associated with appropriate weight-control behavior among adolescents of the Seychelles

BACKGROUND: We examined body image perception and its association with reported weight-control behavior among adolescents in the Seychelles.METHODS: We conducted a school-based survey of 1432 students aging 11-17 years in the Seychelles. Perception of body image was assessed using both a closed-ended question (CEQ) and Stunkard's pictorial silhouettes (SPS). Voluntary attempts to change weight were also assessed.RESULTS: A substantial proportion of the overweight students did not consider themselves as overweight (SPS: 24%, CEQ: 34%), and a substantial proportion of the normal-weight students considered themselves as too thin (SPS: 29%, CEQ: 15%). Logistic regression analysis showed that students with an accurate weight perception were more likely to have appropriate weight-control behavior.CONCLUSIONS: We found that substantial proportions of students had an inaccurate perception of their weight and that weight perception was associated with weight-control behavior. These findings point to forces that can drive the upwards overweight trends.

A bacterial artificial chromosome library for Biomphalaria glabrata, intermediate snail host of Schistosoma mansoni

To provide a novel resource for analysis of the genome of Biomphalaria glabrata, members of the international Biomphalaria glabrata Genome Initiative (biology.unm.edu/biomphalaria-genome.html), working with the Arizona Genomics Institute (AGI) and supported by the National Human Genome Research Institute (NHGRI), produced a high quality bacterial artificial chromosome (BAC) library. The BB02 strain B. glabrata, a field isolate (Belo Horizonte, Minas Gerais, Brasil) that is susceptible to several strains of Schistosoma mansoni, was selfed for two generations to reduce haplotype diversity in the offspring. High molecular weight DNA was isolated from ovotestes of 40 snails, partially digested with HindIII, and ligated into pAGIBAC1 vector. The resulting B. glabrata BAC library (BG_BBa) consists of 61824 clones (136.3 kb average insert size) and provides 9.05 × coverage of the 931 Mb genome. Probing with single/low copy number genes from B. glabrata and fingerprinting of selected BAC clones indicated that the BAC library sufficiently represents the gene complement. BAC end sequence data (514 reads, 299860 nt) indicated that the genome of B. glabrata contains ~ 63% AT, and disclosed several novel genes, transposable elements, and groups of high frequency sequence elements. This BG_BBa BAC library, available from AGI at cost to the research community, gains in relevance because BB02 strain B. glabrata is targeted whole genome sequencing by NHGRI.

Pathoecology and paleodiet in Postclassic: Historic Maya from northern coastal Belize

This paper examines the synergism among diet, disease, and ecology at two related coastal Maya sites in Belize (Marco Gonzalez and San Pedro) for the Postclassic and Historic periods (1350-1650 AD), which immediately follow the Classic period collapse. Stable carbon- and nitrogen-isotope ratios in collagen and stable carbon-isotope ratios in structural carbonate were analysed for bones from 65 humans and a wide variety of faunal species. There are no apparent differences in whole diets or degree of carnivory between individuals with lesions indicative of anemia and those without, but those with lesions appear to have consumed significantly more C4 foods and protein from lower trophic levels. Non-specific infection (periostitis) and vitamin C deficiency (scurvy) are also present in high frequencies and appear to co-occur with lesions indicative of anemia, particularly in childhood. Individuals with scurvy also appear to have consumed significantly more C4 foods than normal individuals. Spondyloarthropathy is common in adults. These findings are discussed in light of: (1) the debate on how anemia versus scurvy are manifest and diagnosed, (2) Spanish ethnohistoric descriptions of the poor state of Maya health at the time of contact, and (3) the Osteological Paradox. We suggest that although this coastal environment exacerbated morbidity because of possible parasitic infection, the inhabitants were probably able to survive physiological stresses better than either their inland contemporaries or their modern counterparts.