Analysis of population genetic structure from Bucaramanga (Colombia) based on gene polymorphisms associated with regulation of blood pressure

Introduction: In spite nearly 40% of the variability in blood pressure can be explained by genetic factors, the identification of genes associated to essential high blood pressure is difficult in populations where individuals have different genetic precedents; in these circumstances it is necessary to determinate whether the population is sub-structured because this can bias studies associated with this disease. Objectives: To determine the genetic structure of the population in Bucaramanga from genetic polymorphisms associated with the regulation of blood pressure: 448G>T, 679C>T y 1711C>T from the gene kinase 4 of the dopaminergic receptor linked to the protein G and Glu298Asp, -786T>C and the VNTR of the intron 4 of the gene of endothelial nitric oxide. Methodology: A sample of 552 unrelated individuals was studied through analysis of Restriction fragment length polymorphism. The allelic, haplotypic and genotypic frequencies were calculated, the Hardy-Weinberg equilibrium was determined and a molecular analysis of variance was performed to determine the genetic structure. Results: 38 Haplotypes were identified, with GCCTG4b as the most frequent (21.2%). The most diverse polymorphism was 448G>T with a frequency of 49.9% for heterozygous. The six polymorphisms were found in genetic equilibrium and genetic structure of populations was not evidenced (FST = 0,0038). Conclusion: The population studied does not present a genetic sub-structure and the polymorphisms analyzed were found in genetic equilibrium, this indicates that the population mixes randomly and there are no sub-groups capable of affecting the results of the association studies. Introducción: A pesar que cerca del 40% de la variabilidad en la presión arterial es explicada por factores genéticos, la identificación de genes asociados a la hipertensión arterial esencial es difícil en poblaciones constituidas por individuos con antecedentes genéticos diferentes; en esta circunstancia se debe determinar si la población está sub-estructurada porque esto puede sesgar los estudios de asociación con esta enfermedad. Objetivo: Determinar la estructura genética de la población de Bucaramanga a partir de polimorfismos genéticos asociados con la regulación de la presión arterial: 448G>T, 679C>T y 1711C>T del gen de la quinasa 4 del receptor dopaminérgico acoplado a proteína G y Glu298Asp, -786T>C y el VNTR del intrón 4 del gen de la sintasa de óxido nítrico endotelial. Metodología: Se estudió una muestra de 552 individuos no relacionados mediante análisis de polimorfismos de longitud de fragmentos de restricción. Se calcularon las frecuencias alélicas, haplotípicas y genotípicas, se determinó el equilibrio de Hardy-Weinberg y se realizó un análisis molecular de varianza para determinar la estructura genética. Resultados: Se identificaron 38 haplotipos siendo GCCTG4b el más frecuente (21.2%). El polimorfismo más diverso fue el 448G>T con una frecuencia de heterocigotos del 49.9%. Los seis polimorfismos se encontraron en equilibrio genético y no se evidenció estructura genética poblacional (FST = 0,0038). Conclusión: La población estudiada no presenta subestructura genética y los polimorfismos analizados se encontraron en equilibrio genético, lo que indica que la población se mezcla aleatoriamente y no existen subgrupos que puedan afectar los resultados de estudios de asociación

The Latin American Consortium of Studies in Obesity (LASO)

Current, high-quality data are needed to evaluate the health impact of the epidemic of obesity in Latin America. The Latin American Consortium of Studies of Obesity (LASO) has been established, with the objectives of (i) Accurately estimating the prevalence of obesity and its distribution by sociodemographic characteristics; (ii) Identifying ethnic, socioeconomic and behavioural determinants of obesity; (iii) Estimating the association between various anthropometric indicators or obesity and major cardiovascular risk factors and (iv) Quantifying the validity of standard definitions of the various indexes of obesity in Latin American population. To achieve these objectives, LASO makes use of individual data from existing studies. To date, the LASO consortium includes data from 11 studies from eight countries (Argentina, Chile, Colombia, Costa Rica, Dominican Republic, Peru, Puerto Rico and Venezuela), including a total of 32 462 subjects. This article describes the overall organization of LASO, the individual studies involved and the overall strategy for data analysis. LASO will foster the development of collaborative obesity research among Latin American investigators. More important, results from LASO will be instrumental to inform health policies aiming to curtail the epidemic of obesity in the region

Cardiovascular disease, chronic kidney disease, and diabetes mortality burden of cardiometabolic risk factors from 1980 to 2010: a comparative risk assessment

Background High blood pressure, blood glucose, serum cholesterol, and BMI are risk factors for cardiovascular diseases and some of these factors also increase the risk of chronic kidney disease and diabetes. We estimated mortality from cardiovascular diseases, chronic kidney disease, and diabetes that was attributable to these four cardiometabolic risk factors for all countries and regions from 1980 to 2010. Methods We used data for exposure to risk factors by country, age group, and sex from pooled analyses of populationbased health surveys. We obtained relative risks for the eff ects of risk factors on cause-specifi c mortality from metaanalyses of large prospective studies. We calculated the population attributable fractions for- each risk factor alone, and for the combination of all risk factors, accounting for multicausality and for mediation of the eff ects of BMI by the other three risks. We calculated attributable deaths by multiplying the cause-specifi c population attributable fractions by the number of disease-specifi c deaths. We obtained cause-specifi c mortality from the Global Burden of Diseases, Injuries, and Risk Factors 2010 Study. We propagated the uncertainties of all the inputs to the fi nal estimates. Findings In 2010, high blood pressure was the leading risk factor for deaths due to cardiovascular diseases, chronic kidney disease, and diabetes in every region, causing more than 40% of worldwide deaths from these diseases; high BMI and glucose were each responsible for about 15% of deaths, and high cholesterol for more than 10%. After accounting for multicausality, 63% (10\ub78 million deaths, 95% CI 10\ub71\u201311\ub75) of deaths from these diseases in 2010 were attributable to the combined eff ect of these four metabolic risk factors, compared with 67% (7\ub71 million deaths, 6\ub76\u20137\ub76) in 1980. The mortality burden of high BMI and glucose nearly doubled from 1980 to 2010. At the country level, age-standardised death rates from these diseases attributable to the combined eff ects of these four risk factors surpassed 925 deaths per 100 000 for men in Belarus, Kazakhstan, and Mongolia, but were less than 130 deaths per 100 000 for women and less than 200 for men in some high-income countries including Australia, Canada, France, Japan, the Netherlands, Singapore, South Korea, and Spain. Interpretation The salient features of the cardiometabolic disease and risk factor epidemic at the beginning of the 21st century are high blood pressure and an increasing eff ect of obesity and diabetes. The mortality burden of cardiometabolic risk factors has shifted from high-income to low-income and middle-income countries. Lowering cardiometabolic risks through dietary, behavioural, and pharmacological interventions should be a part of the globalresponse to non-communicable diseases

La investigación médica en pregrado

ResumenLa producción cientifica de un país y de una institución es considerada un indicador directo del desarrollo científico; Si tomamos como medida de aporte a la comunidad científica la publicación, resalta que el mayor aporte  a la ciencia mundial en revistas ISI(Institute for Scientific Information) está dado por las grandes potencias industriales, siendo los Estados Unidos la de mayor producción, seguida por Japon, Reino Unido y Alemania; en contraste, encontramos que latinoamérica y el Caribe solo aporta el 3% de la producción científica mundial, donde se destacan en la publicación biomédica Brasil, Argentina, Mexico, Venezuela y Chile

Ultraestructura del epitelio de folículos ováricos de la codorniz japonesa Coturnix Coturnix Japonica: Adaptaciones celulares que contribuyen a la formación del vitelo.

Se estudiaron las características ultraestructurales de los folículos ováricos en diferentes estados de crecimiento en la codorniz japonesa, Coturnix co­turnix japónica. El objetivo fue investigar la exis­tencia de adaptaciones morfológicas que pudieran explicar la transferencia de partículas constituyen­tes de vitelo, desde el epitelio folicular al oocito. Con este fin, se sacrificaron por yugulación 16 codornices hembras adultas. Sus ovarios fueron extraídos rápidamente. Pequeños trozos fueron se­leccionados al azar y procesados para microscopia electrónica, utilizando técnicas habituales. Median­te ultramicrótomo se obtuvieron cortes finos, los que fueron teñidos con acetato de uranilo y citrato de plomo. Posteriormente, fueron observados, me­diante microscopio electrónico Zeiss EM-109 y se obtuvieron micrografías.Se describen las células foliculares y se compa­ran los resultados con aquellos previamente repor­tados en otras especies de aves. Se informa el ha­llazgo de una estructura folicular no descrita ante­riormente que denominamos 'complejo polivesicu­lar' y cuya función sería la transferencia de lipopro­teínas desde la célula folicular el oocito durante el período de crecimiento rápido.Palabras claves: Ultraestructura, ovario, folículos, codorniz.AbstractThe ultrastructure of the ovarian follicles, at different stages of growth were studied, in the japanesse quail Coturnix coturnix japonica. The aim was to investigate some morphological adaptations that could explain the transfer of yolk constituents particles from follicular epithelium to oocyte. To this purpose, 16 adult female quails were sacrifized by jugulation, ovaries were quickly drown, sectioned and selected for electron miscrocopy study. Thin sections were obtained by ultramicrotome, stained with uranile acetate and lead citrate and examined under a Zeiss EM-109 electron microscope. Follicullar cells were described and compared with those previously, reported to other avian species. In addition, we note follicular structures not reported before which we named 'polyvesicular complex'. Their function could be related with the lipoproteins transference from follicular cells to oocyte, during the phase of rapid growth.Key words: ultrastructure, ovary, follicles, quail.&nbsp

Ultraestructura del epitelio de folículos ováricos de la codorniz japonesa Coturnix Coturnix Japonica: Adaptaciones celulares que contribuyen a la formación del vitelo.

Se estudiaron las características ultraestructurales de los folículos ováricos en diferentes estados de crecimiento en la codorniz japonesa, Coturnix co­turnix japónica. El objetivo fue investigar la exis­tencia de adaptaciones morfológicas que pudieran explicar la transferencia de partículas constituyen­tes de vitelo, desde el epitelio folicular al oocito. Con este fin, se sacrificaron por yugulación 16 codornices hembras adultas. Sus ovarios fueron extraídos rápidamente. Pequeños trozos fueron se­leccionados al azar y procesados para microscopia electrónica, utilizando técnicas habituales. Median­te ultramicrótomo se obtuvieron cortes finos, los que fueron teñidos con acetato de uranilo y citrato de plomo. Posteriormente, fueron observados, me­diante microscopio electrónico Zeiss EM-109 y se obtuvieron micrografías.Se describen las células foliculares y se compa­ran los resultados con aquellos previamente repor­tados en otras especies de aves. Se informa el ha­llazgo de una estructura folicular no descrita ante­riormente que denominamos 'complejo polivesicu­lar' y cuya función sería la transferencia de lipopro­teínas desde la célula folicular el oocito durante el período de crecimiento rápido.Palabras claves: Ultraestructura, ovario, folículos, codorniz.AbstractThe ultrastructure of the ovarian follicles, at different stages of growth were studied, in the japanesse quail Coturnix coturnix japonica. The aim was to investigate some morphological adaptations that could explain the transfer of yolk constituents particles from follicular epithelium to oocyte. To this purpose, 16 adult female quails were sacrifized by jugulation, ovaries were quickly drown, sectioned and selected for electron miscrocopy study. Thin sections were obtained by ultramicrotome, stained with uranile acetate and lead citrate and examined under a Zeiss EM-109 electron microscope. Follicullar cells were described and compared with those previously, reported to other avian species. In addition, we note follicular structures not reported before which we named 'polyvesicular complex'. Their function could be related with the lipoproteins transference from follicular cells to oocyte, during the phase of rapid growth.Key words: ultrastructure, ovary, follicles, quail.&nbsp

Interethnic differences in the accuracy of anthropometric indicators of obesity in screening for high risk of coronary heart disease.

BACKGROUND: Cut points for defining obesity have been derived from mortality data among Whites from Europe and the United States and their accuracy to screen for high risk of coronary heart disease (CHD) in other ethnic groups has been questioned. OBJECTIVE: To compare the accuracy and to define ethnic and gender-specific optimal cut points for body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) when they are used in screening for high risk of CHD in the Latin-American and the US populations. METHODS: We estimated the accuracy and optimal cut points for BMI, WC and WHR to screen for CHD risk in Latin Americans (n=18 976), non-Hispanic Whites (Whites; n=8956), non-Hispanic Blacks (Blacks; n=5205) and Hispanics (n=5803). High risk of CHD was defined as a 10-year risk > or =20% (Framingham equation). The area under the receiver operator characteristic curve (AUC) and the misclassification-cost term were used to assess accuracy and to identify optimal cut points. RESULTS: WHR had the highest AUC in all ethnic groups (from 0.75 to 0.82) and BMI had the lowest (from 0.50 to 0.59). Optimal cut point for BMI was similar across ethnic/gender groups (27 kg/m(2)). In women, cut points for WC (94 cm) and WHR (0.91) were consistent by ethnicity. In men, cut points for WC and WHR varied significantly with ethnicity: from 91 cm in Latin Americans to 102 cm in Whites, and from 0.94 in Latin Americans to 0.99 in Hispanics, respectively. CONCLUSION: WHR is the most accurate anthropometric indicator to screen for high risk of CHD, whereas BMI is almost uninformative. The same BMI cut point should be used in all men and women. Unique cut points for WC and WHR should be used in all women, but ethnic-specific cut points seem warranted among men