Biology subjects

Martinez-Ezquerro, J. D.

Publications and source records attributed to Martinez-Ezquerro, J. D..

6 recordsLinked to original sources

bioRxiv2023

Physical performance and telomere length in older adults

BackgroundThe fast-paced aging demographic prompts studying risk factors and markers that could predict healthy aging. Telomere length shows promise for assessing a broad spectrum of aging-related phenotypes. Aim of the studyTo assess the association between physical performance and telomere length in Mexican older adults. MethodsIn this observational cross-sectional study, we recruited 323 older adults affiliated with the Instituto Mexicano del Seguro Social (IMSS) and members of the "Cohort of Obesity, Sarcopenia, and Frailty of Older Mexican Adults (COSFOMA). To assess physical performance, we used the Short Physical Performance Battery (SPPB) and stratified individuals into two groups according to their SPPB score into low [≤]7 (L-SPPB) and high >7 (H-SPPB). Absolute telomere length (aTL) was determined by using qPCR. Next, we classified individuals according to their aTL into short [≤]4.22 kb (S-TL) and long >4.22 kb (L-TL). For both SPPB and aTL categories, we calculated the mean and adjusted mean by sex, age, marital status, education, remunerated work, smoking, drinking, cognitive decline, depression, and polypharmacy with 95% CI, including the lower and upper CI (LCImeanUCI). We estimated the effect size between physical performance and telomere length with Cohens d for unequal group sizes. Also, we calculated the odds ratio with 95% confidence intervals, including the lower and upper CI (LCIORUCI) for physical performance according to telomere length categories. ResultsParticipants in the low physical performance category had significantly shorter telomeres (4.14.44.7 mean and 3.54.04.5 kb adjusted mean, p<0.001), in opposition to the high physical performance category (score >7) with longer telomeres (5.55.75.9 mean and 4.75.35.8 kb adjusted mean, p<0.001), with a medium-to-high telomere length effect size (d= 0.762). Finally, the odds of being classified in the low physical activity category increased 2.13.66.1 times per kb of telomere (adjOR 1.73.36.3, p<0.001) compared to the high physical activity group (p<0.001). ConclusionDecreased physical functioning is associated with lower telomere length. Absolute telomere length (aTL) as a possible biomarker for differential diagnosis of healthy and unhealthy aging should be explored further.

genetics↗

bioRxiv2021

Copy number alterations and epithelial-mesenchymal transition genes in diffuse and intestinal gastric cancers in Mexican patients

Gastric cancer (GC) is a malignancy with the highest mortality among diseases of the digestive system worldwide. The study of GC-alterations is crucial to understand tumor biology, to establish important aspects of cancer prognosis and treatment response. Here, we purified DNA and performed whole-genome analysis with high-density arrays in samples from Mexican patients diagnosed with GC: diffuse (DGC) or intestinal (IGC), or non-atrophic gastritis (NAG) samples that served as controls. We identified shared and unique copy number alterations (CNA) between these altered tissues involving key genes and signaling pathways associated with cancer, allowing their molecular distinction and identification of the most relevant molecular functions impacted. When focused on epithelial-mesenchymal transition (EMT) genes, our bioinformatic analysis revealed that the altered network associated with chromosomal alterations included 11 genes shared between DGC, IGC, and NAG, as well as 19 DGC- and 7 IGC-exclusive genes, whose main molecular functions included adhesion, angiogenesis, migration, metastasis, morphogenesis, proliferation, and survival. This study presents the first whole-genome high-density array study in GC from Mexican patients and reveals shared and exclusive CNA-genes in DGC and IGC. In addition, we provide a bioinformatically predicted network focused on CNA-altered genes involved in the EMT, associated with the hallmarks of cancer, as well as precancerous alterations that could lead to gastric cancer. ImplicationsMolecular signatures of diffuse and intestinal GC, predicted bioinformatically, involve common and distinct CNA-EMT genes related to the hallmarks of cancer that are potential candidates for screening GC biomarkers, including early stages.

cancer biology↗

bioRxiv2019

Telomere length and oxidative stress in the progression of Alzheimer’s disease

Alzheimers Disease (AD) is the most common cause of dementia and aging is its major risk factor. Changes in telomere length have been associated with aging and some degenerative diseases. Our aim was to explore some of the molecular changes caused by the progression of AD in a transgenic murine model (3xTg-AD; B6; 129-Psen1 Tg (APPSwe, tauP301L) 1Lfa). Telomere length was assessed by qPCR in both brain tissue and peripheral blood cells and compared between three age groups: 5, 9, and 13 months. In addition, a possible effect of oxidative stress on telomere length and AD progression was explored. Shorter telomeres were found in blood cells of older transgenic mice compared to younger and wild type mice but no changes in telomere length in the hippocampus. An increase in oxidative stress with age was found for all strains but no correlation was found between oxidative stress and shorter telomere length for transgenic mice. Telomere length and oxidative stress are affected by AD progression in the 3xTg-AD murine model. Changes in blood cells are more noticeable than changes in brain tissue, suggesting that systemic changes can be detected early in the disease in this murine model.

neuroscience↗

bioRxiv2018

Information and communication technology, mobile devices, and medical education

IntroductionInformation and communication technologies (ICT) are practical and highly available tools. In medical education, ICTs allow physicians to update their knowledge and remember the necessary information within reach of current mobile devices. ICTs as preparation tools for medical education have not been reported for medical students in Mexico. MethodologyTo assess the use of mobile devices as ICTs with medical education purposes, we distributed a questionnaire through an online survey management system to all the medical students (n=180) from a private university in Mexico City, 100% agreed to participate. We developed a questionnaire based on previous surveys and adapted it to our university. ResultsAll participants reported possession of an electronic mobile device, and 95% used it regularly for learning purposes. Regardless of the school year, the most frequent usage given to these devices was the search and reading of medical articles, the use of medical calculators, and taking notes. As the levels in career advances, there was a reduction in the use of electronic devices. According to the students, the main barriers towards using mobile devices for learning purposes were both the lack of access to the Internet and permission from the professor to use them. ConclusionMost medical students use mobile devices for learning purposes, but usage changes during their education. It is convenient to encourage the use of mobile devices and the development of ICT skills as tools for educational purposes rather than banning their use in schools and hospitals.

scientific communication and education↗

bioRxiv2018

Association of oxidative stress, telomere length, and frailty in an elder population

BackgroundA global aging population requires focusing on the risk factors for unhealthy aging, preventive medicine, and chronic disease management. The identification of adverse health outcomes in older adults has been addressed by the characterization of frailty as a biological syndrome. On the other hand, oxidative stress and telomere length have been suggested as biomarkers of aging.\n\nObjectiveTo study the association of oxidative stress, telomere length, and frailty in an old age population.\n\nMethodsThis was a cross-sectional study based on 2015 data from 202 members from a cohort of older adults (n=202; gender F/M ratio: 133/69; mean age: 69.89 {+/-} 7.39 years). Reactive oxygen species (ROS) were measured by dichlorofluorescin diacetate, and lipid peroxidation by malondialdehyde. Telomere length was determined using qPCR with SYBR Green Master Mix.\n\nResultsStatistical analysis showed an association between telomere length and frailty but no association between oxidative stress on telomere length or frailty.\n\nConclusionsTelomere length could eventually be used as a marker to discriminate between healthy and unhealthy aging as expressed by frailty phenotype. However, oxidative stress seems as just a biological process of aging.

molecular biology↗

bioRxiv2017

Association between the brain-derived neurotrophic factor Val66Met polymorphism and overweight/obesity in Mexican pediatric population

BackgroundThe functional brain-derived neurotrophic factor (BDNF) rs6265 (G196A; Val66Met) single nucleotide polymorphism has been associated with eating disorders, BMI and obesity in distinct populations, both adult and pediatric, with contradictory results involving either Val or Met as the risk variant.\n\nAim of the studyTo determine the association between the BDNF Val66Met polymorphism and BMI in Mexican children and adolescents.\n\nMethodsBDNF Val66Met genotyping by restriction fragment length polymorphism and nutritional status characterized by their BMI-for-age z-scores (BAZ) from pediatric volunteers recruited in Mexico City (n=498) were analyzed by Fishers exact test association analysis. Standardized residuals (R) were used to determine which genotype/allele had the major influence on the significant Fishers exact test statistic. Odds ratios were analyzed to measure the magnitude and direction of the association between genotype and normal weight ([≥] -2 SD < +1 SD) and overweight ([≥] +1 SD, including obesity, Ow+Ob) status with 95% confidence intervals to estimate the precision of the effect as well as 95% credible intervals to obtain the most probable estimate.\n\nResultsComparisons between GG (Val/Val), GA (Val/Met) and AA (Met/Met) genotypes or Met homozygotes vs. Val carriers (combination of GG and GA genotypes) showed significant differences (p=0.034 and p=0.037, respectively) between normal weight and the combined overweight and obese pediatric subjects. Our data showed that children/adolescents homozygous for the A allele have increased risk of overweight compared to the Val carriers (Bayes OR= 4.2, 95% CI**[1.09-33.1]).\n\nConclusionThis is the first study showing the significant association between the BDNF rs6265 AA (Met/Met) genotype and overweight/obesity in Mexican pediatric population.\n\nO_LIMexico has one of the highest pediatric overweight and obesity prevalence\nC_LIO_LIBDNF has been associated with body weight regulation.\nC_LIO_LIThe BDNF rs6265 SNP (G196A; Val66Met) has been associated with eating disorders, BMI and obesity, with contradictory results in both adults and children.\nC_LIO_LIWe found significant associations between BDNF Val66Met AA (Met/) genotype and overweight/obesity in Mexican pediatric population\nC_LIO_LIMet homozygote children/adolescents increased four times the risk of being classified in the overweight group (Ow+Ob) relative to Val carriers\nC_LI

genetics↗