Serum 25-hydroxyvitamin D correlates with systolic blood pressure in obese male schoolchildren / La 25-hidroxivitamina D sérica se correlaciona con la presión arterial sistólica en niños escolares con obesidad

Introduction: childhood obesity is associated with an increased risk of chronic diseases. We aimed to examine the relation between serum levels of 25-hydroxyvitamin D (25[OH]D) and blood pressure in obese schoolchildren. Material and methods: a cross-sectional study in school-age children with obesity. The serum levels of 25(OH)D were measured and classified as sufficient or insufficient/deficient. Blood pressure was measured. Normal values were considered < 90th percentile, elevated blood pressure ≥ 90th to < 95th percentiles, and hypertension ≥ 95th percentile, according to blood pressure reference tables specific for age, sex, and height. A Pearson correlation was performed. Results: a total of 256 obese schoolchildren (123 [48.0 %] females and 133 [51.9 %] males) were evaluated. The prevalence rates of vitamin D deficiency, insufficiency, and sufficiency were 23.4 %, 52.3 %, and 24.2 %, respectively. Normal blood pressure was observed in 101 (39.4 %) children; the frequencies of elevated blood pressure and hypertension were 10.9 % and 49.6 %, respectively. A moderate inverse correlation of 25(OH)D levels with systolic blood pressure levels (r = -0.54, p = 0.03) was observed. When analyzed by sex, a significantly high inverse correlation between 25(OH)D levels and systolic blood pressure was observed in males (r = -0.85 and p ≤ 0.001). No significant correlation was found in females (systolic r = -0.16 and p = 0.67; diastolic r = -0.15 and p = 0.812). When performing the multiple regression analysis, the 25(OH)D levels and BMI were the significant predictors for systolic blood pressure. Conclusions: we identified an inverse correlation between 25[OH]D levels and systolic blood pressure in male schoolchildren with obesity (AU)

Introducción: la obesidad infantil se asocia con un mayor riesgo de desarrollar enfermedades crónicas. El objetivo fue analizar la relación entre los niveles séricos de 25-hidroxivitamina D (25[OH]D) y la presión arterial (PA) en escolares obesos. Material y métodos: estudio transversal en niños en edad escolar con obesidad. Los niveles séricos de 25(OH)D se clasificaron como suficientes e insuficientes/deficientes. Los valores de PA se clasificaron como normales si < percentil 90, presión elevada entre los percentiles ≥ 90 y < 95, e hipertensión si ≥ percentil 95, de acuerdo con las tablas de referencia de la PA, específicas para cada edad, sexo y altura. Se realizaron una correlación de Pearson y una regresión múltiple. Resultados: se evaluaron 256 escolares obesos (123 [48,0 %] mujeres y 133 [51,9 %] hombres). La frecuencia de la deficiencia, insuficiencia y suficiencia de vitamina D fue del 23,4 %, 52,3 % y 24,2 %, respectivamente. Se observó una PA normal en 101 (39,4 %) niños; las frecuencias de la PA elevada y la hipertensión fueron del 10,9 % y 49,6 %, respectivamente. Se observó una correlación inversa moderada de los niveles de 25(OH)D con los niveles de presión arterial sistólica (PAS) (r = -0,54; p = 0,03). Cuando se analizó por sexos, se observó una correlación inversa entre los niveles de 25(OH)D y la PAS en los niños (r = -0,85; p ≤ 0,001). No se encontró ninguna correlación significativa en las niñas (sistólica, r = -0,16; p = 0,67; diastólica, r = -0,15; p = 0,812). Al realizar el análisis de regresión múltiple, los niveles de 25(OH)D y el IMC fueron predictores significativos de la PAS. Conclusiones: identificamos una correlación inversa entre los niveles de 25[OH]D y la PAS en niños escolares con obesidad (AU)

National retrospective cohort study to identify risk factors for in-hospital 30-day lethality in laboratory-confirmed cases of influenza.

OBJECTIVE: To identify factors associated with the risk of death in adolescent and adult inpatients with laboratory-positive (reverse-transcription polymerase chain reaction) influenza in Mexico during consecutive influenza seasons (2018-2020). METHODS: A retrospective cohort study used national surveillance system data, enrolling 3.422 individuals. The association between various risk factors and 30-day in-hospital lethality were evaluated through risk ratios (RRs) and 95% confidence intervals (CIs). RESULTS: The lethality rate was 18.1%. Flu vaccination history (RR=0.56, 95% CI 0.42-0.78), early antiviral drug administration (≤2 days from symptom onset [reference ≥5 days], RR=0.68, 95% CI 0.58-0.81), and a history of asthma (RR=0.66, 95% CI 0.47-0.95) showed protective effects against influenza-attributable death. Mechanical ventilator support produced the highest increase in death risk (RR=3.31, 95% CI 2.89-3.79). Male sex, older age, AH1N1 subtype, and other chronic diseases were also associated with fatal in-hospital influenza-related outcomes. CONCLUSIONS: Our findings highlight the major relevance of promoting immunization in high-risk individuals, together with ensuring early and effective antiviral management in suspected influenza cases.

Predictors of severe symptomatic laboratory-confirmed SARS-CoV-2 reinfection.

OBJECTIVE: The aim of the study was to evaluate factors predicting severe symptomatic laboratory-confirmed (via Reverse transcription polymerase chain reaction, RT-PCR polymerase chain reaction) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection. STUDY DESIGN: This is a nationwide retrospective cohort study that was conducted in Mexico. METHODS: Data from 258 reinfection cases (at least 28 days between both episodes onset) were analyzed. We used risk ratios (RRs) and 95% confidence intervals (CIs) to evaluate predictors of severe (dyspnea requiring hospital admission) secondary SARS-CoV-2 infection. RESULTS: The risk of severe disease was 14.7%, and the observed overall fatality rate was 4.3%. Patients with more serious primary disease were more likely to develop severe symptoms (39.5% vs. 5.5%, P < 0.001) during reinfection. In multiple analysis, factors associated with an increased risk of severe symptomatic SARS-CoV-2 reinfection were increasing age (RRper year = 1.007, 95% CI = 1.003-1.010), comorbidities (namely, obesity [RR = 1.12, 95% CI = 1.01-1.24], asthma [RR = 1.26, 95% CI = 1.06-1.50], type 2 diabetes mellitus [RR = 1.22, 95% CI = 1.07-1.38]), and previous severe laboratory-confirmed coronavirus disease 2019 (RR = 1.20, 95% CI = 1.03-1.39). CONCLUSIONS: To the best of our knowledge, this is the first study evaluating disease outcomes in a large set of laboratory-positive cases of symptomatic SARS-CoV-2 reinfection, and factors associated with illness severity were characterized. Our results may contribute to the current knowledge of SARS-CoV-2 pathogenicity and to identify populations at increased risk of a poorer outcome after reinfection.

Estudio de cohorte retrospectivo nacional para identificar los factores de riesgo de letalidad por hospitalización durante 30 días en casos de gripe confirmados por laboratorio / National retrospective cohort study to identify risk factors for in-hospital 30-day lethality in laboratory-confirmed cases of influenza

Objetivo Identificar los factores asociados a riesgo de muerte en pacientes adolescentes y adultos hospitalizados con gripe confirmada en laboratorio (reacción en cadena de la polimerasa con transcriptasa inversa) en México durante temporadas consecutivas de gripe (2018-2020). Pacientes y métodos Estudio de cohorte retrospectivo en el que se utilizaron datos del sistema de vigilancia nacional con 3.422 sujetos inscritos. Se evaluó la asociación entre el riesgo a la exposición y el riesgo de letalidad hospitalaria durante 30 días mediante el estudio de los riesgos relativos (RR) y los intervalos de confianza (IC) del 95%. Resultados La tasa de letalidad fue del 18,1%. Los antecedentes de vacunación frente a la gripe (RR = 0,56; IC 95%: 0,42-0,78), la administración de fármacos antivirales (≤ dos días desde la aparición de los síntomas [referencia: ≥ 5 días]; RR = 0,68; IC 95%: 0,58-0,81) y el historial de asma (RR = 0,66; IC 95%: 0,47-0,95) mostraron efectos protectores frente a la muerte atribuible a la gripe. La ventilación mecánica causó el mayor aumento del riesgo de muerte (RR = 3,31; IC 95%: 2,89-3,79). También se asoció a una mayor letalidad hospitalaria por gripe el hecho de ser hombre, tener edad avanzada, el subtipo AH1N1 y otras enfermedades crónicas. Conclusiones Nuestros hallazgos recalcan la gran importancia de fomentar la inmunización de individuos de alto riesgo, a la vez que se asegura un tratamiento antiviral temprano y eficaz en los casos sospechosos de gripe (AU)

Objective To identify factors associated with the risk of death in adolescent and adult inpatients with laboratory-positive (reverse-transcription polymerase chain reaction) influenza in Mexico during consecutive influenza seasons (2018-2020). Patients and methods A retrospective cohort study used national surveillance system data, enrolling 3422 individuals. The association between various risk factors and 30-day in-hospital lethality were evaluated through risk ratios (RR) and 95% confidence intervals (CI). Results The lethality rate was 18.1%. Flu vaccination history (RR = 0.56, 95% CI 0.42-0.78), early antiviral drug administration (≤ two days from symptom onset [reference ≥ 5 days], RR = 0.68, 95% CI 0.58-0.81), and a history of asthma (RR = 0.66, 95% CI 0.47-0.95) showed protective effects against influenza-attributable death. Mechanical ventilator support produced the highest increase in death risk (RR = 3.31, 95% CI 2.89-3.79). Male sex, older age, AH1N1 subtype, and other chronic diseases were also associated with fatal in-hospital influenza-related outcomes. Conclusions Our findings highlight the major relevance of promoting immunization in high-risk individuals, together with ensuring early and effective antiviral management in suspected influenza cases (AU)

Predictors of laboratory-positive COVID-19 in children and teenagers.

OBJECTIVE: The aim of the study was to identify factors predicting laboratory-positive coronavirus disease 2019 (COVID-19) in pediatric patients with acute respiratory symptoms. STUDY DESIGN: We conducted a cross-sectional analysis of a prospective cohort study. METHODS: Data from 1849 individuals were analyzed. COVID-19 was confirmed (reverse transcription-quantitative polymerase chain reaction) in 15.9% of patients, and factors predicting a positive test result were evaluated through prevalence odds ratios and 95% confidence intervals. RESULTS: Increasing age, personal history of obesity, and household contact with a case were found to be associated, in the multiple regression model, with increased odds of a positive test result. Young patients residing in areas with higher population sizes, as well as those with severe respiratory symptoms, were less likely to be laboratory confirmed. CONCLUSIONS: Early identification and isolation of children and teenagers with suggestive symptoms of COVID-19 is important to limit viral spread. We identified several factors predicting the laboratory test result. Our findings are relevant from a public health policy perspective, particularly after the restart of in-person academic activities.

Nicorandil Affects Mitochondrial Respiratory Chain Function by Increasing Complex III Activity and ROS Production in Skeletal Muscle Mitochondria.

Adenosine triphosphate (ATP)-dependent potassium channels openers (KATP) protect skeletal muscle against function impairment through the activation of the mitochondrial KATP channels (mitoKATP). Previous reports suggest that modulators of the mitochondrial KATP channels have additional effects on isolated mitochondria. To determine whether the KATP channel opener nicorandil has non-specific effects that explain its protective effect through the mitochondrial function, chicken muscle mitochondria were isolated, and respiration rate was determined pollarographically. The activity of the electron transport chain (ETC) complexes (I-IV) was measured using a spectrophotometric method. Reactive oxygen species (ROS) levels and lipid peroxidation were assessed using flow cytometry and thiobarbituric acid assay, respectively. Both KATP channel opener nicorandil and KATP channel blocker 5-hydroxydecanoate (5-HD) decreased mitochondrial respiration; nicorandil increased complex III activity and decreased complex IV activity. The effects of nicorandil on complex III were antagonized by 5-HD. Nicorandil increased ROS levels, effect reverted by either 5-HD or the antioxidant N-2-mercaptopropionyl glycine (MPG). None of these drugs affected lipid peroxidation levels. These findings suggest that KATP channel opener nicorandil increases mitochondrial ROS production from complex III. This results by partially blocking electron flow in the complex IV, setting electron carriers in a more reduced state, which is favored by the increase in complex III activity by nicorandil. Overall, our study showed that nicorandil like other mitochondrial KATP channel openers might not act through mitoKATP channel activation.

National retrospective cohort study to identify risk factors for in-hospital 30-day lethality in laboratory-confirmed cases of influenza. / Estudio de cohorte retrospectivo nacional para identificar los factores de riesgo de letalidad por hospitalización durante 30 días en casos de gripe confirmados por laboratorio.

OBJECTIVE: To identify factors associated with the risk of death in adolescent and adult inpatients with laboratory-positive (reverse-transcription polymerase chain reaction) influenza in Mexico during consecutive influenza seasons (2018-2020). PATIENTS AND METHODS: A retrospective cohort study used national surveillance system data, enrolling 3422 individuals. The association between various risk factors and 30-day in-hospital lethality were evaluated through risk ratios (RR) and 95% confidence intervals (CI). RESULTS: The lethality rate was 18.1%. Flu vaccination history (RR = 0.56, 95% CI 0.42-0.78), early antiviral drug administration (≤ two days from symptom onset [reference ≥ 5 days], RR = 0.68, 95% CI 0.58-0.81), and a history of asthma (RR = 0.66, 95% CI 0.47-0.95) showed protective effects against influenza-attributable death. Mechanical ventilator support produced the highest increase in death risk (RR = 3.31, 95% CI 2.89-3.79). Male sex, older age, AH1N1 subtype, and other chronic diseases were also associated with fatal in-hospital influenza-related outcomes. CONCLUSIONS: Our findings highlight the major relevance of promoting immunization in high-risk individuals, together with ensuring early and effective antiviral management in suspected influenza cases.

Current model systems for the study of preeclampsia.

Preeclampsia (PE) is a pregnancy complex disease, distinguished by high blood pressure and proteinuria, diagnosed after the 20th gestation week. Depending on the values of blood pressure, urine protein concentrations, symptomatology, and onset of disease there is a wide range of phenotypes, from mild forms developing predominantly at the end of pregnancy to severe forms developing in the early stage of pregnancy. In the worst cases severe forms of PE could lead to systemic endothelial dysfunction, eclampsia, and maternal and/or fetal death. Worldwide the fetal morbidity and mortality related to PE is calculated to be around 8% of the total pregnancies. PE still being an enigma regarding its etiology and pathophysiology, in general a deficient trophoblast invasion during placentation at first stage of pregnancy, in combination with maternal conditions are accepted as a cause of endothelial dysfunction, inflammatory alterations and appearance of symptoms. Depending on the PE multifactorial origin, several in vitro, in vivo, and in silico models have been used to evaluate the PE pathophysiology as well as to identify or test biomarkers predicting, diagnosing or prognosing the syndrome. This review focuses on the most common models used for the study of PE, including those related to placental development, abnormal trophoblast invasion, uteroplacental ischemia, angiogenesis, oxygen deregulation, and immune response to maternal-fetal interactions. The advances in mathematical and computational modeling of metabolic network behavior, gene prioritization, the protein-protein interaction network, the genetics of PE, and the PE prediction/classification are discussed. Finally, the potential of these models to enable understanding of PE pathogenesis and to evaluate new preventative and therapeutic approaches in the management of PE are also highlighted. Impact statement This review is important to the field of preeclampsia (PE), because it provides a description of the principal in vitro, in vivo, and in silico models developed for the study of its principal aspects, and to test emerging therapies or biomarkers predicting the syndrome before their evaluation in clinical trials. Despite the current advance, the field still lacking of new methods and original modeling approaches that leads to new knowledge about pathophysiology. The part of in silico models described in this review has not been considered in the previous reports.

Comprehensive analysis of venom from the scorpion Centruroides tecomanus reveals compounds with antimicrobial, cytotoxic, and insecticidal activities.

Centruroides tecomanus is a medically important scorpion of the state of Colima (Mexico). This communication reports the identification of venom components of this scorpion with biological activity over insects/crickets (Acheta domestica), crustaceans/fresh water shrimps (Cambarellus montezumae), and mammalians/mice (Mus musculus, strain CD1). It also describes the pharmacological effects on cell lines in culture (L5178Y cells, HeLa cells, HuTu cells and Jurkat E6-1 cells), as well as on several types of bacteria (see below). The soluble venom of this scorpion was fractionated by high-performance liquid chromatography (HPLC) and collected separately in twelve independent fractions collected over 60 min run (5 min time apart each other). The HPLC components of fraction VII were lethal to all three species used for assay. The IVth fraction had a toxic effect on freshwater shrimps. In this species, fractions VI, VII and VIII were all lethal. For crickets, fractions V and VI were toxic and fraction VII was lethal. In mouse, the lethal components were found in fraction VII, whereas fraction VIII was toxic, but not lethal, at the doses assayed. The molecular weight of peptides from the various group of fractions were identified by mass spectrometry determination. Components lethal to mice showed molecular weights from 7013 to 7487 Da. Two peptides were obtained in homogeneous form and shown to be lethal to the three species of animal used for assay. The soluble venom tested on L5178Y cell line survival was shown to be cytotoxic, at 10-100 µg/mL concentration, when compared to control murine splenocytes (p = 0.007). The soluble venom applied to Hela, Hutu and Jurkat cell lines did not show cytotoxic effects at these concentrations. On the contrary, it seems to have a proliferative effect. However the HPLC fractions I, III, VI and XII do have a cytotoxic effect on Jurkat E06-1 cells in culture at 200 µg/mL concentration. The antimicrobial activity of the venom fractions on Staphylococcus aureus (gram-positive), Escherichia coli, Pseudomonas aeruginosa y Salmonella spp (gram-negative) was measured, using the liquid inhibition growth system. The four strains of bacteria used were susceptible to fractions III and IV, affecting all four bacterial strains at concentrations below 5 µg/mL.

HPV 16 and 18 viral loads are greater in patients with high-grade cervical epithelial lesions.

BACKGROUND: Cervical cancer is the second most common cancer in women worldwide. High-risk infection with HPV type 16 or type 18 is the most important risk factor associated with the development of cervical cancer. AIMS: To determine the viral load of HPV-16 and HPV-1 8 in samples from women with cervical epithelial lesion in the State of Colima, Mexico. MATERIALS AND METHODS: A cross-sectional analytic study was conducted that included 45 samples positive for HPV- 16 and 45 samples positive for HPV-1 8 from patients with cervical cancer or precursor lesion. Real time PCR was employed to determine the number of copies /101 cells. Viral load was determined in the two groups of patients and correlated with tumor grade. RESULTS: THe authors found that the HPV-1 6 viral load was greater than that of HPV-18 through a Mann-Whitney U analysis, resulting in ap = 0.000; as the malignancy of the cervical lesion progressed, the viral load increased, and HPV-16 showed a moderate positive association with an r = 0.509 and a p = 0.000, whereas HPV-18 showed a weak positive correlation with an r = 0.372 and a p = 0.0 12. CONCLUSIONS: The viral load of HPV-16 was greater than that of HPV-18. The HPV-16 viral load had a moderate positive association in relation to cervical lesion severity, whereas the viral load of HPV- 18 had a weak positive correlation with respect to the cervical lesion grade.

Positive association between vascular endothelial growth factor (VEGF) -2578 C/A variant and prostate cancer.

BACKGROUND: Vascular endothelial growth factor (VEGF) gene is an important angiogenesis regulator related to cancer development and progression. We evaluated the association between -2578 C/A (rs699947) VEGF polymorphism and PCa in Mexican subjects, to contribute to knowledge of VEGF role in genetic epidemiology of prostate cancer (PCa). OBJECTIVE: The aim of this study was to evaluate the association between -2578 C/A VEGF variant and PCa in Mexican population. METHODS: A total of 249 men (77 PCa cases and 172 controls) from the Northwestern region of Mexico were screened for the -2578 C/A VEGF variant. The polymorphism was determined by polymerase chain reaction-based restriction analysis. RESULTS: Genotype frequencies for C/C, C/A, and A/A, were 0.48, 0.49, 0.03 for cases and 0.41, 0.45, 0.14 for controls respectively. Genotype A/A of -2578 VEGF variant reduces the risk of PCa in an 84% among studied population (Odds Ratio 0.16; 95% CI: 0.04-0.71, P=0.007). C/C carriers showed an increased PCa risk of 6.1 times among the study population. CONCLUSIONS: Inheritance of -2578 A/A genotype of VEGF gene may modify PCa susceptibility risk in Mexican population.

Intraprostatic distribution and long-term follow-up after AdV-tk immunotherapy as neoadjuvant to surgery in patients with prostate cancer.

A phase I-II study to evaluate gene-mediated cytotoxic immunotherapy in newly diagnosed prostate cancer before radical prostatectomy was conducted in Monterrey, Mexico. First, to investigate delivery of adenovirus to the prostate, fluorescently labeled vector was injected into fresh prostatectomy specimens and distribution was visually analyzed. The optimal volume and site instillation was then used for transrectal ultrasound guided intraprostatic injection in 10 patients with adenocarcinoma scheduled for radical prostatectomy. Each received two apical and two basal 0.5 ml injections of AdV-tk for a total of 1 × 10(11) vp followed by 14 days of prodrug. Nine patients continued to tumor resection: six high risk, one intermediate and two low risk. In vivo vector distribution was analyzed from the resected tissue of four patients. Patients were monitored for tumor progression and acute and long-term safety. For vector delivery, two apical and two basal injections of 0.5 ml led to optimal organ-wide distribution ex vivo and in vivo. Cytotoxicity was evidenced by transient rise in PSA and tumor histology. There were no significant adverse events deemed related to the treatment and no late toxicities after median follow-up of 11.3 years. All six high-risk patients had positive surgical margins and one had seminal vesicle involvement. Despite slow PSA rise post surgery in three of these patients, none developed metastases. The intermediate- and low-risk patients had complete resections and none have progressed. In conclusion, in vivo transrectal ultrasound guided instillation of an adenoviral vector into four sites in the prostate was practical as an outpatient procedure, well tolerated and led to distribution throughout the intraprostatic tumor mass. AdV-tk demonstrated no significant acute or late toxicities. Trends in PSA and disease progression conveyed the possibility of a sustained immune response against residual disease.

Olfactomedin-like 3 (OLFML3) gene expression in baboon and human ocular tissues: cornea, lens, uvea, and retina.

BACKGROUND: Olfactomedin-like is a family of polyfunctional polymeric glycoproteins. This family has at least four members. One member of this family is OLFML3, which is preferentially expressed in placenta but is also detected in other adult tissues including the liver and heart. However, its orthologous rat gene is expressed in the iris, sclera, trabecular meshwork, retina, and optic nerve. METHODS: OLFML3 messenger amplification was performed by RT-PCR from human and baboon ocular tissues. The products were cloned and sequenced. RESULTS: We report OLFML3 expression in human and baboon eye. The full coding DNA sequence has 1221 bp, from which an open reading frame of 406 amino acid was obtained. The baboon OLFML3 gene nucleotidic sequence has 98% and amino acidic 99% similarity with humans. CONCLUSIONS: OLFML3 gene expression in human and baboon ocular tissues and its high similarity make the baboon a powerful model to deduce the physiological and/or metabolic function of this protein in the eye.

Folate levels and N(5),N(10)-methylenetetrahydrofolate reductase genotype (MTHFR) in mothers of offspring with neural tube defects: a case-control study.

BACKGROUND: Neural tube defects (NTDs) have been associated with biochemical factors involved in the conversion of homocysteine to methionine as folate deficiency and the mutation 677T in the N(5),N(10)-methylenetetrahydrofolate reductase gene (MTHFR). METHODS: A case-control study was performed to detect this mutation in 38 unrelated women with NTD deceased products and 31 mothers without antecedents of NTD offspring. All products were born in Nuevo León (northeastern Mexico) during 1997. Erythrocyte and plasmatic folate levels and the genotype of the 677 polymorphism at the MTHFR locus were analyzed in both groups. RESULTS: Although no significant differences were found in mean blood folate levels, the percentage of women in the case group with erythrocyte folate levels <160 ng/mL was significantly higher than in the control group (75 vs. 51.2%, p <0.05). The proportion of women with plasma folate levels <3.5 ng/mL was higher in the case group (16.2 vs. 0%, p <0.01). Genotype analysis demonstrated a significantly higher proportion of 677T homozygous mothers with NTD products (39.6 vs. 9.1%, p <0.05). Allele frequencies for the 677T mutation were 0.55 and 0.36 for cases and controls, respectively. The odds ratio (OR) for having a NTD product was 6.1 (95%, CI 1.56-23.6) for homozygous 677T mothers vs. homozygous 677C and heterozygous mothers. Significantly low levels of erythrocyte folate were found in the 677C homozygous case group and in plasma folate in the 677C/677T heterozygous case mothers. CONCLUSIONS: Our study suggests that folate deficiency and MTHFR unfavorable genotype in mothers are important risk factors for severe NTD phenotype in our population.

[677T mutation of the MTHFR gene in adenomas and colorectal cancer in a population sample from the Northeastern Mexico. Preliminary results]. / Mutación 677T del gen MTHFR en adenomas y cáncer colorrectal en una muestra de la población del noreste de México. Resultados preliminares.

INTRODUCTION: Adequate intake of folates has been associated to low prevalence of colon cancer. Methylenetetrahydrofolate reductase enzyme (MTHFR) plays an important role in folate metabolism. The role of the 677 mutation at the MTHFR gene in the risk for colorectal cancer remains controversial. A recent report established that this mutation has a high prevalence in the healthy Mexican population. AIMS: To analyze the prevalence of 677T MTHFR mutation in patients with colorectal cancer and controls without chronic gastrointestinal disorders. METHODS: Seventy-four colorectal cancer, 32 adenomas and 110 normal samples were analyzed. Patients and controls were matched for sex and age. For each sample, DNA isolation, PCR, and mutation detection by restriction enzyme digestion were performed to determine the allele at the 677 position in the MTHFR gene. RESULTS: Genotype 677C/677C was found in 18.7, 20.3, and 30.9% in adenomas, cancer lesions and controls, respectively. Frequencies of the 677C/677T genotype were 59.4, 56.7, and 47.3%, in adenomas, cancer lesions, and controls, respectively. Genotype 677T/677T was found in 21.9, 23.0, and 21.8% in adenomas, cancer lesions, and controls, respectively. The odds ratio between genotypes carrying the mutation (T/T and C/T) and normal genotype (CC) was 1.81 (IC 95% 0.97-3.3), chi 2 = 3.5, p = 0.06. CONCLUSION: Our results showed that persons who carry the 677T mutation at MTHFR locus have a tendency for an increased risk for colorectal cancer. This study supports the basic concept that low levels of folic acid contribute with the colorectal cancer pathogenesis. Our lack of statistic significance may be due to reduced sample size.

[Genetics and molecular medicine in cardiology]. / Genética y medicina molecular en cardiología.

The discoveries on molecular aspects of cellular function are changing the concepts of health and disease. All medical fields, including cardiology, have been enriched with several diagnostic test to determine predisposition and to detect molecular dysfunctions. This review on the genetic and molecular aspects of cardiovascular diseases is written at the Centenary of the rediscovery of Mendel's principles on heredity and at the time of the announcement of the end of the human genome sequencing task. The review starts with considerations on the pluricellular constitution of the human body, and the principles of genetics with their molecular bases; including a short description of the methods for gene mapping. The following sections give a historic synopsis on the concepts of medical genetics, molecular medicine, and the Human Genome Project. The review ends with a brief description of the spectrum of genetic diseases, using examples of cardiovascular diseases.

[Genetic aspects of asthma]. / Aspectos genéticos del asma.

Asthma is a complex disease associated with bronchial hyperreactivity and atopy, making asthma a disease with a phenotype that has been clinically difficult to define. Despite intense research, prevalence of asthma remain relatively high. The key reason for the high prevalence and morbility is that the fundamental mechanisms predisposing individuals to the development of asthma are not understood. Familial aggregation observed in this pathology has prompted for the search of an involved genetic component. This task is difficult due to the complex nature of asthma. A universally accepted definition for this disease is not available, clinical expression can be modulated by environmental factors, and inheritance does not follow a clear Mendelian pattern. Establishment of more precise clinical and laboratory criteria has improved the design and interpretation of genetic studies. Twin analysis and segregation studies have demonstrated an important genetic component with a probably multifactorial pattern of inheritance. "Sib pair" studies and familial segregation analyses have shown linkage between some chromosomal regions and asthma, including chromosome 5, 6, 7, 11 and 14. The search for major genes in these chromosomal segments has been focused on loci involved in the allergic process. Among these, the loci for IL-9 and IL-13 in chromosome 5 seem to play an important role in the pathogenesis of asthma. Understanding the fundamental gene-environmental interactions in the development of asthma should lead to earlier identification of susceptible individuals and more effective approaches for disease prevention.