Association between maternal diet, smoking, and the placenta MTHFR 677C/T genotype and global placental DNA methylation.

INTRODUCTION: The placenta provides nutrients to the fetus, and it has protective effects against harmful substances. Unhealthy maternal diets and toxic agents might increase free radical (FR) production. Elevated FR levels are associated with a high risk of oxidative stress, which may cause DNA damage. DNA might be oxidized in the placenta, occasionally affecting its methylation profile due to 8-hidroxy-2'-deoxyguanosine formation. METHODS: This study assessed 130 mothers and their children. The maternal's nutritional patterns were determined using the Food Frequency Questionnaire. Information on smoking and alcohol consumption was collected during the medical examination. Data on placental DNA were obtained to determine the MTHFR 677C/T genotype and the proportion of placental DNA methylation (pDNAm). RESULTS: Consumption of vitamins and folic acid was above 85%. The pDNAm was found to be correlated with gestational age and coffee intake. Mothers with a smoking history had a low pDNAm. Placentas with the TT genotype had a higher but not significant pDNAm. In the placentas with the CC/CT genotype, the pDNAm was positively associated with carbohydrate and biotin intake. However, the TT genotype was negatively associated with folate and vegetable intake. DISCUSSION: The pDNAm was positively associated with coffee intake, but not with macro-, and micronutrient intake. However, it was negatively associated with cigarette smoking. The placentas with the CC/CT genotype had a lower pDNAm than those with the TT genotype. In the placentas with the CC/CT or TT genotype, methylation was positively, and negatively associated with micro- or macronutrients, respectively.

Frequency of respiratory virus-associated infection among children and adolescents from a tertiary-care hospital in Mexico City.

Acute respiratory infections (ARIs) are a major cause of morbidity and mortality among children. The causative pathogens show geographic and seasonal variations. We retrospectively evaluated the frequency and seasonality of respiratory pathogens in children and adolescents (age: 0-19 years) with ARIs treated between January 1, 2021, and March 31, 2022, at a single center in Mexico. Out of 2400 patients, 1,603 were diagnosed with SARS-CoV-2 infection and 797 were diagnosed with other common respiratory pathogens (CRPs). Of the 797 patients, 632 were infected with one CRP and 165 with > 2 CRPs. Deaths occurred only in SARS-CoV-2-infected patients. Rhinovirus/Enterovirus, respiratory syncytial virus B, and parainfluenza virus 3 were the most prevalent in cases with single and multiple infections. CRP showed a high frequency between autumn and winter of 2021, with higher incidence of hospitalization compared to COVID-19. The main comorbidities were immunosuppression, cardiovascular disease (CD), and asthma. The frequency of CRPs showed a downward trend throughout the first half of 2021. CRPs increased in single- and co-infection cases between the fourth and fifth waves of COVID-19, probably due to decreased nonpharmaceutical interventions and changes in diagnostic tests. Age, cyanosis (symptom), and immunosuppression (comorbidity) were found to differentiate between SARS-CoV-2 infection and CRP infection.

Opitz GBBB syndrome with total anomalous pulmonary venous connection: A new MID1 gene variant.

BACKGROUND: Opitz GBBB syndrome (GBBB) is an X-linked disease characterized by midline defects, including congenital heart defects. We present our diagnostic approach to the identification of GBBB in a consanguineous family in which two males siblings were concordant for a total anomalous connection of pulmonary veins and minor facial dysmorphias. METHODS: Targeted exome sequencing analysis of a 380-gene panel associated with cardiovascular disease was performed on the propositus. Interpretative analysis of the exome results was conducted, and 3D models of the protein changes were generated. RESULTS: We identified a NM_000381.4:c.608G>A;p.(Arg203Gln) change in MID1, affecting the conformation of the B-box 2 domain of the protein, with a zinc finger structure and associated protein interactions. This clinical phenotype is consistent with GBBB; however, the type of congenital heart disease observed in this case has not been previously reported. CONCLUSION: A new likely pathogenic variant on MID1 c.608G>A was found to be associated with Opitz GBBB syndrome.

Dietary and Antioxidant Vitamins Limit the DNA Damage Mediated by Oxidative Stress in the Mother-Newborn Binomial.

During pregnancy, appropriate nutritional support is necessary for the development of the foetus. Maternal nutrition might protect the foetus from toxic agents such as free radicals due to its antioxidant content. In this study, 90 mothers and their children were recruited. DNA damage mediated by oxidative stress (OS) was determined by the levels of 8-hidroxy-2'-deoxyguanosine (8-OHdG) in the plasma of women and umbilical cord blood. The mothers and newborns were categorised into tertiles according to their 8-OHdG levels for further comparison. No relevant clinical differences were observed in each group. A strong correlation was observed in the mother−newborn binomial for 8-OHdG levels (Rho = 0.694, p < 0.001). In the binomial, a lower level of 8-OHdG was associated with higher consumption of calories, carbohydrates, lipids, and vitamin A (p < 0.05). In addition, the levels of 8-OHdG were only significantly lower in newborns from mothers with a higher consumption of vitamin A and E (p < 0.01). These findings were confirmed by a significant negative correlation between the 8-OHdG levels of newborns and the maternal consumption of vitamins A and E, but not C (Rho = −0.445 (p < 0.001), −0.281 (p = 0.007), and −0.120 (p = 0.257), respectively). Multiple regression analysis showed that the 8-OHdG levels in mothers and newborns inversely correlated with vitamin A (ß = −1.26 (p = 0.016) and −2.17 (p < 0.001), respectively) and pregestational body mass index (ß = −1.04 (p = 0.007) and −0.977 (p = 0.008), respectively). In conclusion, maternal consumption of vitamins A and E, but not C, might protect newborns from DNA damage mediated by OS.

Diet and Maternal Obesity Are Associated with Increased Oxidative Stress in Newborns: A Cross-Sectional Study.

Overweight and obesity have become a world-health public problem, mainly for developing countries. Both health conditions have a higher prevalence among women of childbearing age. Physiopathology, overweight and obesity are characterized by a chronic oxidative stress status, which has deleterious effects on mothers and children. Hence, we determine whether the qualities of diet during pregnancy and maternal pregestational body mass index (BMI) are associated with increased oxidative stress markers in mothers and newborns. Two hundred forty-two (242) mother-newborn pairs were classified according to their pregestational BMI. Information on food intake was collected using a food frequency questionnaire in the third trimester of pregnancy. Levels of Malondialdehyde (MDA) and Nitric Oxide (NO) were measured in plasma from mothers at the end of the third trimester of pregnancy and from cord blood at birth. MDA and NO levels in mother-newborn pairs with maternal pregestational overweight or obesity were higher than in mother-newborn pairs with pregestational normal weight. For women (and newborns) who had a higher intake of fruit and vegetables, the levels of NO and MDA were lower. Lastly, women with pregestational obesity had lower fruit and vegetable intake during pregnancy and higher levels of oxidative stress and in their newborns.

Genotyping of the Major SARS-CoV-2 Clade by Short-Amplicon High-Resolution Melting (SA-HRM) Analysis.

The genome of the SARS-CoV-2 virus, the causal agent of the COVID-19 pandemic, has diverged due to multiple mutations since its emergence as a human pathogen in December 2019. Some mutations have defined several SARS-CoV-2 clades that seem to behave differently in terms of regional distribution and other biological features. Next-generation sequencing (NGS) approaches are used to classify the sequence variants in viruses from individual human patients. However, the cost and relative scarcity of NGS equipment and expertise in developing countries prevent studies aimed to associate specific clades and variants to clinical features and outcomes in such territories. As of March 2021, the GR clade and its derivatives, including the B.1.1.7 and B.1.1.28 variants, predominate worldwide. We implemented the post-PCR small-amplicon high-resolution melting analysis to genotype SARS-CoV-2 viruses isolated from the saliva of individual patients. This procedure was able to clearly distinguish two groups of samples of SARS-CoV-2-positive samples predicted, according to their melting profiles, to contain GR and non-GR viruses. This grouping of the samples was validated by means of amplification-refractory mutation system (ARMS) assay as well as Sanger sequencing.

Implementation of high-resolution melting analysis of the porcupine (PORCN) gene for molecular diagnosis of focal dermal hypoplasia: Identification of a novel mutation.

BACKGROUND: Focal dermal hypoplasia (FDH) is rare X-linked dominant disease characterized by atrophy and linear pigmentation of the skin, split hand/foot deformities and ocular anomalies. FDH is caused by mutations of the Porcupine (PORCN) gene, which encodes an enzyme that catalyzes the palmitoylation of Wnt ligands required for their secretion. High resolution melting analysis (HRM) is a technique that allows rapid, labor-efficient, low-cost detection of genomic variants. In the present study, we report the successful implementation of HRM in the molecular diagnosis of FDH. METHODS: Polymerase chain reaction and HRM assays were designed and optimized for each of the coding exons of the PORCN gene, processing genomic DNA samples form a non-affected control and a patient complying with the FDH diagnostic criteria. The causal mutation was characterized by Sanger sequencing from an amplicon showing a HRM trace suggesting heterozygous variation and was validated using an amplification-refractory mutation system (ARMS) assay. RESULTS: The melting profiles suggested the presence of a variant in the patient within exon 1. Sanger sequencing revealed a previously unknown C to T transition replacing a glutamine codon for a premature stop codon at position 28, which was validated using ARMS. CONCLUSIONS: Next-generation sequencing facilitates the molecular diagnosis of monogenic disorders; however, its cost-benefit ratio is not optimal when a single, small or medium size causal gene is already identified and the clinical diagnostic presumption is strong. Under those conditions, as it is the case for FDH, HRM represents a cost- and labor-effective approach.

Inhibition of the Na+/H+ antiporter induces cell death in TF-1 erythroleukemia cells stimulated by the stem cell factor.

Leukemia cells produce acidic metabolites due to their high metabolic condition. An alkaline pHi (intracellular pH) shift, caused by activation of the Na+/H+ exchange, is an important event in the mechanism of growth factor activity. However, the role of the Na(+)/H(+) exchanger in the survival of erythroleukemia TF-1 cells has not yet been studied in detail. The aim of this study was to identify the effects of 5-(N-ethyl-N-isopropyl) amiloride (EIPA), a highly specific blocker of the Na(+)/H(+) exchanger, on the survival of SCF-dependent TF-1 cells. The effects of EIPA on survival and mitochondrial membrane potential were studied when exposing wild type TF-1 cells and TF-1 cells expressing bcl-2 to EIPA for 48h. Ectopic expression of the bcl-2 gene maintained a mildly alkaline pH and prevented the simultaneous appearance of apoptosis and autophagy (typically displayed by TF-1 cells) in the presence of EIPA. Consistent with Stem Cell Factor (SCF) function, we found that this molecule rescued TF-1 cells during autophagy but not apoptosis, allowing these cells to subsequently respond to GM-CSF. Serum deprivation or SCF withdrawal induced cell death at 36h in TF-1 and TF-1 neo cells, whereas TF-1/bcl-2 cells tended to undergo apoptosis and show acidic vacuoles after 96h, pointing to a transient anti-apoptotic effect. The present study shows the suppressive effect of EIPA on the proliferation of leukemia cell line stimulated with SCF, apparently by decreasing the mitochondria membrane potential and averting alkalinization. Through the constitutive expression of bcl-2, TF-1 cells were survival factor independent. Proliferation in these cells was not affected by EIPA at the concentrations used against parental TF-1 cells, indicating that the inhibitory effect in SCF-stimulated cells can be attributed to specific blocking of the Na(+)/H(+) exchanger.