Analysis of SIRT1 genetic variants in young Mexican individuals: relationships with overweight and obesity.

The high prevalence of obesity in Mexico starting from the early stages of life is concerning and represents a major public health problem. Genetic association studies have reported that single nucleotide variants (SNVs) in SIRT1, an NAD+-dependent deacetylase that plays an important role in the regulation of metabolic cellular functions, are associated with multiple metabolic disorders and the risk of obesity. In the present study, we analyzed the effect that the SNVs rs1467568 and rs7895833 of the SIRT1 gene may have on cardiometabolic risk factors in a young adult population from Mexico. A cross-sectional study was carried out with young adults between the ages of 18 and 25 who had a body mass index (BMI) greater than 18.5 kg/m2. This study included 1122 young adults who were classified into the normal weight (n = 731), overweight group (n = 277), and obesity group (n = 114) according to BMI of whom 405 and 404 volunteers were genotyped for rs1467568 and rs7895833 respectively using TaqMan probes through allelic discrimination assays. We found that the male sex carrying the G allele of rs7895833 had slightly lower BMI levels (p = 0.009). Furthermore, subjects carrying rs1467568 (G allele) showed a 34% lower probability of presenting with hyperbetalipoproteinemia where female carrying rs1467568 had lower levels of total cholesterol (p = 0.030), triglycerides (p = 0.026) and LDL cholesterol (p = 0.013). In conclusion, these findings suggest that the presence of both SNVs could have a non-risk effect against dyslipidemia in the Mexican population.

Glycemia and associated factors in a pediatric population in Mexico.

Aims: In this study, we evaluated the association of sociodemographic, lifestyle and cardiometabolic factors with blood glucose levels in children and adolescents in Mexico. Methods: An analytical cross-sectional study of 642 children and adolescents aged 6 to 19 years from different educational centers located in municipalities of the state of San Luis Potosí, Mexico, was carried out. Pearson χ2 and Spearman correlation tests and multiple linear regression models were used to evaluate the associations of the variables with glycemia. Results: The prevalence of prediabetes was 8.0% in both sexes. Male participants were more likely to develop hyperglycemia than female participants (OR 2.7, 95% CI: 1.5-5.0). The variables associated with glucose levels were male sex, high socioeconomic status, inadequate diet, high blood pressure, and increased total cholesterol, LDL cholesterol, and triglycerides, which also explained up to 15.6% (p < 0.05) of the variability in glucose concentrations. Conclusion: The detection of sociodemographic, lifestyle and cardiometabolic factors in children and adolescents will contribute to the implementation of prevention strategies for cardiometabolic diseases, among which prediabetes is common.

Uricaemia and associated health determinants in a paediatric population in Mexico.

BACKGROUND AND AIM: Uric acid (UA) is a product of the catabolism of purines, and its increase in blood may be related to the development of cardiometabolic diseases. Whether UA is the result or causal determinant of the appearance of risk factors for cardiometabolic disease is not yet known. UA levels among the young student population in San Luis Potosi have increased in recent years, which may be indicative of a serious future public health concern. Therefore, the objective of this study was to evaluate the association of sociodemographic, lifestyle and cardiometabolic determinants with UA levels in children and adolescents in San Luis Potosí. METHODS AND RESULTS: A total of 730 students (54.1% female and 45.9% male, 6-19 years old) participated in the study. The subjects attended one of five public schools located in San Luis Potosí. Venous blood samples were collected, blood serum was separated by centrifugation, and UA concentrations were measured with an automated analytical platform. UA was associated with most of the independent variables studied. It presented a positive correlation with body mass index (r = 0.363, p < 0.01). Male sex, socioeconomic status, total screen time, exercise, adequate sleep, systolic blood pressure, total cholesterol, and high-density lipoprotein cholesterol explained 23%-39% (p < 0.001) of the variability of plasma concentrations of UA in children and adolescents. CONCLUSION: Early detection of these determinants will prevent future diseases. Moreover, it will help with the implementation of preventive strategies that could improve the health of this population.

Single-walled carbon nanotubes (SWCNTs) induce vasodilation in isolated rat aortic rings.

Single-walled carbon nanotubes (SWCNTs) are used in biological systems with impact in biomedicine in order to improve diagnostics and treatment of diseases. However, their effects upon the vascular system, are not fully understood. Endothelium and smooth muscle cells (SMC) communicate through release of vasoactive factors as nitric oxide (NO) to maintain vascular tone. The aim of this study was to evaluate the effect of SWCNTs on vascular tone using isolated rat aortic rings, which were exposed to SWCNTs (0.1, 1 and 10 µg/mL) in presence and absence of endothelium. SWCNTs induced vasodilation in both conditions, indicating that this effect was independent on endothelium; moreover that vasodilation was NO-independent, since its blockage with L-NAME did not modify the observed effect. Together, these results indicate that SWCNTs induce vasodilation in the macrovasculature, may be through a direct interaction with SMC rather than endothelium independent of NO production. Further investigation is required to fully understand the mechanisms of action and mediators involved in the signaling pathway induced by SWCNTs on the vascular system.

[Obtaining zona-free ova from the golden hamster (Mesocricetus auratus Waterhouse)]. / Obtención de óvulos de hamster dorado (Mesocricetus auratus Waterhouse) libres de zona pelúcida.

Our methodology for obtaining zona-free ova from golden hamster females (Mesocricetus Auratus Waterhouse) is described here. Five groups of 5 females were superovulated injecting intraperitoneally pregnant mare gonadothropins (PMG) at different dosages. The control group received 0.25 ml of distilled water. We harvested 653 ova from the stimulated females with an average of 32.65 per individual (range 16-52). The control group produced a total of 50 ova with an average of 10 (range 0-14). PMG optimum dose was 25 IU with an average of 39 (S.D. +/- 10.93) (n = 195 ova). The best conditions for denuding the cumulus was a 0.01% hyaluronidase solution with an average time of 10 minutes (S.D. +/- 03'56"). The optimum conditions for digesting the zona was 0.20% trypsin during 03'20" (S.D. +/- 01'19"). The proof that the ova were not damaged by the procedure was by means of a supravital stain (Eosin Y). All mature ova (N = 681) were not affected by enzymes or manipulation. Final preparation used a 1% acetic acid fixation and staining with 0.01% methylene blue, both acting for 1-3 minutes. Animal gametes give us the opportunity to substitute human ova in biology of reproduction studies and experiments, avoiding technical, ethical and moral problems.