Development and tracking of central patterns of subcutaneous fat of rural South African youth: Ellisras longitudinal study

<p>Abstract</p> <p>Background</p> <p>Individuals grow and accumulate central patterns of body fat into the diseases they will suffer from as older adults. The need to elicit the development and tracking of central patterns of body fat from younger age into adolescent remains to be explored.</p> <p>Method</p> <p>Skinfolds measurements were done according to the standard procedures in the Ellisras Longitudinal Growth and Health Study. In total, 2,225 children--550 preschool and 1,675 primary school--aged 3-10 years (birth cohorts 1993 to 1986) were enrolled at baseline in 1996 and followed through out the eight-year periodic surveys. In 2003, 1,771 children--489 preschool and 1,282 primary school--were still in the study.</p> <p>Results</p> <p>The development of triceps, biceps, suprailiac and suscapular skinfolds of Ellisras girls were significantly higher (p < 0.001 to 0.05) compared to boys over time. The tracking coefficient between the initial measurements and the subsequent measurements was higher for skinfolds (r about 0.63) than for skinfold ratios (r about 0.43). Longitudinal tracking coefficient measuring the association between the initial measurements and all the follow up measurements simultaneously was about 0.57.</p> <p>Conclusion</p> <p>The accumulation of central patterns of body fat of Ellisras children starts in childhood and adolescence spurt with Ellisras girls acquiring more than boys over time. High significant tracking of skinfold thickness while the skinfold ratios show low and insignificant tracking over time. The magnitude of central patterns of body fat accumulation over time requires further investigation to clarify their association with risk factors for cardiovascular diseases.</p

Current smoking behaviour among rural South African children: Ellisras Longitudinal Study

<p>Abstract</p> <p>Background</p> <p>The use of tobacco products is the major cause of chronic diseases morbidity and mortality. Most smokers start the smoking habits from childhood and adolescent stages.</p> <p>Method</p> <p>This was a cross-sectional study. A total of 1654 subjects (854 boys and 800 girls), aged 11 to 18 years, who were part of the Ellisras Longitudinal Study completed the questionnaire. Association between tobacco products use and habits, attitudes and beliefs were explored in this study. Logistic regression was used to estimate the association.</p> <p>Results</p> <p>The prevalence of tobacco product use increases with increasing (4.9 to 17.1%) age among boys whereas girls do not smoke cigarette but only considerable number (1.0 to 4.1%) use home made tobacco products (pipe and snuff) among the Ellisras rural children. Parents and grand parents play a significant (about 50%) role in influencing smoking behaviour among the Ellisras rural children. Seeing actors smoking on TV shows was positively associated (p < 0.05) with smoking (OR = 2.3 95%CI (1.3-4.1 and OR = 2.3 95%CI 1.3-4.1 after adjusting for age and gender). However, women who smoke cigarette were significantly (p < 0.001) associated with success and success and wealth (OR = 2.8, 95% CI 1.5-5.2) even after adjusting for age and gender (OR = 2.9 95% CI 1.5-5.4).</p> <p>Conclusion</p> <p>The usage of tobacco products was high among older boys. Girls did not smoke cigarette. This tobacco use behaviour mirrors the cultural norms and adult behaviour. The association of this tobacco used products with biological parameters will shed more light on the health of these children over time.</p

Health Status and Permanent Loss to Follow up of Ellisras Longitudinal Study Subjects: Rural South African Context

Noncommunicable diseases (NCDs) are responsible for two out of three deaths worldwide with their profile changing from one country to another. But evidence to sustained these changes are still very limited in rural South African population. The well-characterized Ellisras Longitudinal Study (ELS) provides a unique opportunity of mapping some of these changes in vulnerable adolescent and young adults. The objective is we determined the extent of NCD risk factors derived from anthropometric and blood pressure measurements affected Ellisras Longitudinal Study (ELS) subjects over time for those who died or permanently lost to follow-up. A total of 2238 subjects aged 3–10 years (born between 1994 and 1986) were randomly selected to take part of the Ellisras Longitudinal Study (ELS) in November 1996. The attrition rate of ELS subjects based on death ranges between 0.71 and 3.73% for boys and 0.75 and 4.89% for girls. The prevalence of sever undernutrition ranges from 3.2 to 53%, moderate undernutrition ranges from 9.7 to 28.8%, while mild undernutrition ranges from 17.9 to 59.1% for both males and females. The prevalence of undernutrition was high while hypertension, obesity, and overweight were low in the population. The identification of appropriate NCD indicators for mortality in rural South African population needs more consideration and evaluation

Socio-economic status and menarcheal age in urban african schoolgirls in the western cape, South Africa

The impact of different socio-economic levels, height, weight and sum of four skinfolds on the menarcheal age of 302 Black, South African school girls ranging in age from 8 to 17 years was researched. Socioeconomic status was obtained by means of a questionnaire that focused on the education, income, and occupations of the parents of the participants and the accommodation in which they were reared. Menarcheal age was obtained by means of a questionnaire. When restricted to those girls who had reached menarche, the mean age was found to be 14.34 years (SD=0.93). The application of survival analysis revealed an estimated median age of 14.25 years with a 95% confidence interval estimate of 14.08 and 14.58. Based on the log-rank statistic, significant differences were found in the survival curves of the different SES categories (p=0.0098). It was found that lower SES corresponded to curves having longer survival times, i.e. later ages of menarche. Differences were found in weight (p=0.037) and in height (p=0.0042), but no difference in SUM4 (p=0.44), between girls who have reached menarche and those who have not.DHE

Substrate and product inhibition of hydrogen production by the extreme thermophile, Caldicellulosiruptor saccharolyticus.

Substrate and product inhibition of hydrogen production during sucrose fermentation by the extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus was studied. The inhibition kinetics were analyzed with a noncompetitive, nonlinear inhibition model. Hydrogen was the most severe inhibitor when allowed to accumulate in the culture. Concentrations of 5-10 mM H2 in the gas phase ( partial hydrogen pressure (pH2) of (1-2) · 104 Pa) initiated a metabolic shift to lactate formation. The extent of inhibition by hydrogen was dependent on the density of the culture. The highest tolerance for hydrogen was found at low volumetric hydrogen production rates, as occurred in cultures with low cell densities. Under those conditions the critical hydrogen concentration in the gas phase was 27.7 mM H2 ( pH2 of 5.6 · 104 Pa); above this value hydrogen production ceased completely. With an efficient removal of hydrogen sucrose fermentation was mainly inhibited by sodium acetate. The critical concentrations of sucrose and acetate, at which growth and hydrogen production was completely inhibited (at neutral pH and 70°C), were 292 and 365 mM, respectively. Inorganic salts, such as sodium chloride, mimicked the effect of sodium acetate, implying that ionic strength was responsible for inhibition. Undissociated acetate did not contribute to inhibition of cultures at neutral or slightly acidic pH. Exposure of exponentially growing cultures to concentrations of sodium acetate or sodium chloride higher than ca. 175 mM caused cell lysis, probably due to activation of autolysins. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 255-262, 2003

Nanoencapsulated capsaicin changes migration behavior and morphology of madin darby canine kidney cell monolayers

We have developed a drug delivery nanosystem based on chitosan and capsaicin. Both substances have a wide range of biological activities. We investigated the nanosystem’s influence on migration and morphology of Madin Darby canine kidney (MDCK-C7) epithelial cells in comparison to the capsaicin-free nanoformulation, free capsaicin, and control cells. For minimally-invasive quantification of cell migration, we applied label-free digital holographic microscopy (DHM) and single-cell tracking. Moreover, quantitative DHM phase images were used as novel stain-free assay to quantify the temporal course of global cellular morphology changes in confluent cell layers. Cytoskeleton alterations and tight junction protein redistributions were complementary analyzed by fluorescence microscopy. Calcium influx measurements were conducted to characterize the influence of the nanoformulations and capsaicin on ion channel activities. We found that both, capsaicin-loaded and unloaded chitosan nanocapsules, and also free capsaicin, have a significant impact on directed cell migration and cellular motility. Increase of velocity and directionality of cell migration correlates with changes in the cell layer surface roughness, tight junction integrity and cytoskeleton alterations. Calcium influx into cells occurred only after nanoformulation treatment but not upon addition of free capsaicin. Our results pave the way for further studies on the biological significance of these findings and potential biomedical applications, e.g. as drug and gene carriers

Magnetic interactions in iron superconductors: A review

High temperature superconductivity in iron pnictides and chalcogenides emerges when a magnetic phase is suppressed. The multi-orbital character and the strength of correlations underlie this complex phenomenology, involving magnetic softness and anisotropies, with Hund's coupling playing an important role. We review here the different theoretical approaches used to describe the magnetic interactions in these systems. We show that taking into account the orbital degree of freedom allows us to unify in a single phase diagram the main mechanisms proposed to explain the (\pi,0) order in iron pnictides: the nesting-driven, the exchange between localized spins, and the Hund induced magnetic state with orbital differentiation. Comparison of theoretical estimates and experimental results helps locate the Fe superconductors in the phase diagram. In addition, orbital physics is crucial to address the magnetic softness, the doping dependent properties, and the anisotropies.Comment: Invited review article for a focus issue of Comptes Rendus Physique: 26 pages, 10 figures. Revised version, as accepted. Small changes throughout the text plus new subsection (Sec. IIIE

Gap symmetry and structure of Fe-based superconductors

The recently discovered Fe-pnictide and chalcogenide superconductors display low-temperature properties suggesting superconducting gap structures which appear to vary substantially from family to family, and even within families as a function of doping or pressure. We propose that this apparent nonuniversality can actually be understood by considering the predictions of spin fluctuation theory and accounting for the peculiar electronic structure of these systems, coupled with the likely 'sign-changing s-wave' (s\pm) symmetry. We review theoretical aspects, materials properties and experimental evidence relevant to this suggestion, and discuss which further measurements would be useful to settle these issues.Comment: 86 pages, revie