Association of vitamin D, retinol and zinc deficiencies with stunting in toddlers: findings from a national study in Iran.

OBJECTIVE: The objective of this study was to investigate the association of serum levels of 25(OH)D3 (vitamin D), retinol (vitamin A) and zinc with stunting in a large sample of Iranian toddlers. STUDY DESIGN: This was a cross-sectional study. METHODS: A total of 4261 children, aged 10-36 months, who had Iranian birth certificates were included in the present study. Weight and height were measured by experienced professionals in accordance with standard protocols. Stunting was defined as a height-for-age z-score of <-1 standard deviation (SD) based on the World Health Organization (WHO) criteria (the WHO Child Growth Standards median). Serum levels of 25(OH)D3, retinol and zinc were examined based on standard methods. RESULTS: The mean age of the study participants was 19.2 ± 8.4 months. A significant inverse association was found between serum retinol concentrations and the odds of stunting such that after controlling for potential confounders, toddlers in the highest quartile of serum retinol levels had 29% lower odds of stunting than those in the lowest quartile (odds ratio [OR]: 0.71, 95% confidence interval [CI]: 0.53-0.97). Furthermore, a significant inverse association was found between serum levels of retinol and stunting in girls (OR: 0.57, 95% CI: 0.34-0.94), urban toddlers (OR: 0.66, 95% CI: 0.44-0.99) and those who did not use nutritional supplements (OR: 0.70, 95% CI: 0.52-0.95). Although serum 25(OH)D3 levels were not significantly associated with stunting in the overall study population, we found a positive association among toddlers who used nutritional supplements. No significant association was found between serum levels of zinc and stunting. CONCLUSION: We found a significant inverse association between serum levels of retinol and stunting in toddlers aged 10-36 months.

Metformin use and risk of fracture: a systematic review and meta-analysis of observational studies.

INTRODUCTION: No study is available summarizing earlier publications on the association between metformin use and risk of fracture. This systematic review and meta-analysis were conducted to summarize earlier findings on the association between metformin use and risk of fracture. METHODS: We conducted a systematic search on all published articles up to October 2018 using online databases including PubMed/Medline, ISI Web of Science, and Scopus. Observational studies that considered metformin use as the exposure variable and bone fracture as the main outcome variable or as one of the outcome variables and participants included were 18 years and older were included in the systematic review. Publications in which hazard ratios (HRs), rate or risk ratios (RRs), or odds ratios (ORs) were reported as effect size were included in the meta-analysis. RESULTS: Totally, three cohort studies, one cross-sectional study, one nested case-control study, and one case-control study were included in this systematic review and meta-analysis. When seven effect sizes from six studies were combined, a significant inverse association between metformin use and risk of fracture was observed (RR 0.82; 95% CI 0.72, 0.93). No significant between-study heterogeneity was found (I2 = 22.4%, Pheterogeneity = 0.25). In addition, no evidence of publication bias was seen using Egger's test (P = 0.99). CONCLUSION: We found that metformin use was inversely associated with the risk of fracture.

The effect of L-arginine supplementation on body composition and performance in male athletes: a double-blinded randomized clinical trial.

This corrects the article DOI: 10.1038/ejcn.2016.266.

The effect of l-arginine supplementation on body composition and performance in male athletes: a double-blinded randomized clinical trial.

BACKGROUND/OBJECTIVE: Athletes used a lot of dietary supplements to achieve the more muscle mass and improve their athletic performance. The objective of this study was to investigate the effect of l-arginine supplementation on sport performance and body composition in male soccer players. SUBJECTS/METHODS: This double-blinded, randomized and placebo-controlled trial was conducted on 56 male soccer players, with age range of 16-35, who referred to sport clubs in Isfahan, Iran. Subjects were randomly assigned to either l-arginine or placebo groups. Athletes received daily either 2 g per day l-arginine supplement or the same amount of placebo (maltodextrin) for 45 days. Sport performance and also body mass index (BMI), body fat mass (BFM) and lean body mass (LBM) were measured at the beginning and end of the study. Also, 3-day dietary records were collected at three different time points (before, in the middle of, and at the end of the study). RESULTS: The mean age of subjects was 20.85±4.29 years. Sport performance (VO2 max) significantly increased in l-arginine supplementation group (4.12±6.07) compared with placebo group (1.23±3.36) (P=0.03). This increase remained significant even after adjustment of baseline values, physical activity and usual dietary intake of subjects throughout the study. No significant effect of l-arginine supplementation was found on weight, BMI, BFM and LBM. CONCLUSIONS: l-arginine supplementation (2 g per day) could increase the sport performance in male athletes, but had no effect on anthropometric measurements, including BMI, BFM and LBM. So, further studies are needed to shed light our findings.

Optimization of solid-phase extraction using artificial neural networks and response surface methodology in combination with experimental design for determination of gold by atomic absorption spectrometry in industrial wastewater samples.

Solid-phase extraction (SPE) is often used for preconcentration and determination of metal ions from industrial and natural samples. A traditional single variable approach (SVA) is still often carried out for optimization in analytical chemistry. Since there is always a risk of not finding the real optimum by single variation method, more advanced optimization approaches such as multivariable approach (MVA) should be applied. Applying MVA optimization can save both time and chemical materials, and consequently decrease analytical costs. Nowadays, using artificial neural network (ANN) and response surface methodology (RSM) in combination with experimental design (MVA) are rapidly developing. After prediction of model equation in RSM and training of artificial neurons in ANNs, the products were used for estimation of the response of the 27 experimental runs. In the present work, the optimization of SPE using single variation method and optimization by ANN and RSM in combination with central composite design (CCD) are compared and the latter approach is practically illustrated.

Isotype, distribution and target analysis of lymphocyte reactive antibodies in patients with human immunodeficiency virus infection.

Anti-lymphocyte (ALA) antibodies were investigated by using both microcytotoxicity and immunofluorescence analyses in 87 subjects with different clinical features of human immunodeficiency virus (HIV) infection. A similar mean percentage of killing in microcytotoxicity assays using heterologous lymphocytes as cellular target was recorded in four groups of patients, including 36 HIV-seropositive asymptomatic subjects, 34 patients with HIV-induced lymphadenopathy syndrome (LAS), 13 with acquired immunodeficiency syndrome (AIDS)-related complex (ARC), and 4 patients with the full-blown AIDS. Conversely, an increasing percentage of ALA-positive subjects paralleled the evolution of the HIV infection. The majority of ALA were IgM isotype with a significant reactivity against T cells. This specificity was indifferently directed to CD3+, CD4+, and CD8+ lymphocytes. In additional experiments employing enzymatic digestion of lymphocyte membrane antigens, we demonstrated that CD4 and CD8 receptors were digested by the pronase, whereas CD3 molecules were highly resistant. Subsequent flow cytometry analyses using these pronase-digested T cells showed that reactivity of ALA for their target was unchanged. Our data suggest that antigenic specificities of ALA in HIV infection are resistant to pronase treatment and are not related to CD4 and CD8 molecules.