Search

In this work, we fabricated scaffolds for epithelial cell differentiation based on functional fibers. Chitosan, PCL, and PLLA composite scaffolds were electrospun under two controlled atmospheres. SEM results have shown yarns (<300 nm), strings (∼500 nm), and ribbons (∼2 µm). DSC and TGA indicate the main melting temperature ∼61 °C and a degradation temperature at 277 °C. Aqueous swell and UV sterilization (10 min) processes were tested before performing epithelial cell cultures over selected electrospun substrates. Propagation of the immortalized human keratinocyte cell line HaCaT (24 h) on scaffolds, its non-cytotoxic effect (95% relative to control), and cell differentiation characteristics were observed. [ABSTRACT FROM AUTHOR]

Aim: We measured the frequency of nuclear abnormalities of 210 blood samples from the umbilical cord, since human fetuses are exposed to environmental mixtures of pesticides that induce DNA damage. Methods: The determinations were made through the micronucleus assay test in lymphocytes from the umbilical cord blood of newborns whose mothers live in Ahome (n = 105) and Guasave (n = 105), Sinaloa, Mexico. Results: The average frequency of anomalies in 1000 cells were, respectively: micronucleus 0.4 vs. 2.9, pyknotic cells 18.3 vs. 109.2, chromatin condensation 7.7 vs. 150.1, karyolitic cells 1.8 vs. 24.4, and binucleated cells 4.9 vs. 74.6. The calculated Pearson correlation factors of nuclear abnormality frequencies between both municipalities were low and negative, suggesting that they did not correlate between the Ahome and Guasave newborns and indicating a higher number of mothers exposed in Guasave. Conclusion: Our data suggest that monitoring nuclear abnormalities in umbilical cord blood samples could be a useful tool to identify transplacental mutagens perfusion that is being discharged into the local environment. [ABSTRACT FROM AUTHOR]

Exposure to fine particulate matter (PM2.5) and ozone (O3) above US EPA standards is associated with Alzheimer's disease (AD) risk, while Mn toxicity induces parkinsonism. Mexico City Metropolitan Area (MCMA) children have pre- and postnatal sustained and high exposures to PM2.5, O3, polycyclic aromatic hydrocarbons, and metals. Young MCMA residents exhibit frontal tau hyperphosphorylation and amyloid-β (Aβ)1 - 42 diffuse plaques, and aggregated and hyperphosphorylated α-synuclein in olfactory nerves and key brainstem nuclei. We measured total prion protein (TPrP), total tau (T-tau), tau phosphorylated at threonine 181 (P-Tau), Aβ1-42, α-synuclein (t-α-syn and d-α-synuclein), BDNF, insulin, leptin, and/or inflammatory mediators, in 129 normal CSF samples from MCMA and clean air controls. Aβ1-42 and BDNF concentrations were significantly lower in MCMA children versus controls (p = 0.005 and 0.02, respectively). TPrP increased with cumulative PM2.5 up to 5 μg/m3 and then decreased, regardless of cumulative value or age (R2 = 0.56). TPrP strongly correlated with T-Tau and P-Tau, while d-α-synuclein showed a significant correlation with TNFα, IL10, and IL6 in MCMA children. Total synuclein showed an increment in childhood years related to cumulated PM2.5, followed by a decrease after age 12 years (R2 = 0.47), while d-α-synuclein exhibited a tendency to increase with cumulated PM2.5 (R2 = 0.30). CSF Aβ1-42, BDNF, α-synuclein, and TPrP changes are evolving in young MCMA urbanites historically showing underperformance in cognitive processes, odor identification deficits, downregulation of frontal cellular PrP, and neuropathological AD and PD hallmarks. Neuroprotection of young MCMA residents ought to be a public health priority. [ABSTRACT FROM AUTHOR]

Objective. Our aim was to evaluate possible associations between consumption of micronutrients involved in one-carbon metabolism, MTHFR genotypes, and global DNA methylation in pregnant women. Methods. A semi-quantitative dietary questionnaire was administered to 195 women during their first trimester in Morelos, Mexico. Two functional polymorphisms of the key folate-metabolizing gene, i.e. MTHFR 677 C>T and 1298 A>C, as well as global DNA methylation were assessed in peripheral blood drawn during the interview. Results. Independent of maternal age and caloric intake, vitamin B6 deficiency was associated with 1.8 fold increased risk of hypomethylation in women carrying the MTHFR 677 T allele. Conclusions. There exists a subpopulation that is more susceptible to B vitamin deficiencies. [ABSTRACT FROM AUTHOR]