The first genome-wide association study in the Argentinian and Chilean populations identifies shared genetics with Europeans in Alzheimer's disease.

INTRODUCTION: Genome-wide association studies (GWAS) are fundamental for identifying loci associated with diseases. However, they require replication in other ethnicities. METHODS: We performed GWAS on sporadic Alzheimer's disease (AD) including 539 patients and 854 controls from Argentina and Chile. We combined our results with those from the European Alzheimer and Dementia Biobank (EADB) in a meta-analysis and tested their genetic risk score (GRS) performance in this admixed population. RESULTS: We detected apolipoprotein E ε4 as the single genome-wide significant signal (odds ratio  = 2.93 [2.37-3.63], P = 2.6 × 10-23 ). The meta-analysis with EADB summary statistics revealed four new loci reaching GWAS significance. Functional annotations of these loci implicated endosome/lysosomal function. Finally, the AD-GRS presented a similar performance in these populations, despite the score diminished when the Native American ancestry rose. DISCUSSION: We report the first GWAS on AD in a population from South America. It shows shared genetics modulating AD risk between the European and these admixed populations. HIGHLIGHTS: This is the first genome-wide association study on Alzheimer's disease (AD) in a population sample from Argentina and Chile. Trans-ethnic meta-analysis reveals four new loci involving lysosomal function in AD. This is the first independent replication for TREM2L, IGH-gene-cluster, and ADAM17 loci. A genetic risk score (GRS) developed in Europeans performed well in this population. The higher the Native American ancestry the lower the GRS values.

67Ga as a biosensor of iron needs in different organs: Study performed on male and female rats subjected to iron deficiency and exercise.

The aim of the present study was to determine the iron needs in different organs and tissues using 67Ga as a biosensor in males and females rats subjected to iron deficiency (ID) and voluntary exercise (EX). 67Ga citrate was injected i.p. to female and male Wistar rats (n=5/sex/group). Groups: Control (sedentary conditions), Control+EX, ID and ID+EX. To determine the 67Ga uptake, samples from the following regions of interest (ROIs) were extracted 12h post-injection: blood, liver, gonads, bone marrow, heart, adrenal glands, skeletal muscle, stomach, kidney, eyeball, sciatic nerve, small intestine and peritoneum. The total 67Ga uptake was 412% higher in ID subjects than in control subjects, being 1011% higher in ID-males than ID-females. In ID-females, the ROIs with the greater 67Ga uptake were blood, kidney and bone marrow, while in ID-males they were sciatic nerve, eyeball and adrenals, which demonstrates that the biodistribution differed between sexes in sedentary conditions but when subjected to EX, the biodistribution was similar in each sex group although females had a greater 67Ga uptake. In ID+EX subjects, the ROIs that showed the highest uptake were sciatic nerve, eyeball and adrenal glands. Using 67Ga as a biosensor, it is possible to identify the needs of iron that each organ requires to perform their functions in normal physiological conditions. In addition, a higher or lower 67Ga uptake in a specific organ may indicate its malfunction or show damage.

Modelos matemáticos en memoria de reconocimiento de palabras: un análisis roc multinivel / Mathematical Models in Word Recognition Memory: A Multilevel Analysis Roc

En esta investigación se muestran los modelos más eficientes desde el punto de vista experimental y formal para la evaluación de la memoria de reconocimiento de ítemspalabras: En primer lugar se muestra un modelo matemático general que subyace a las diferentes formas de registro de datos. En segundo lugar se controla experimentalmente la elección, organización y tiempos de presentación del estímulo (ítems-palabras en castellano). En tercer lugar se aplica un análisis multinivel para modelar todos los niveles de respuesta de los participantes en las pruebas de memoria de reconocimiento. En cuarto lugar, se evalúa mediante escalas de estimación (EE) y mediante las características operativas del receptor (ROC) propias de la teoría de la detección de señales (TDS) y de los modelos de umbral. Los resultados concuerdan principalmente con un modelo de detección de señales, cuando los estímulos son palabras de frecuencia alta, y con un modelo de umbral (o de diferente varianza) cuando los estímulos son palabras de clase abierta; mientras que las palabras de frecuencia baja ocupan un lugar intermedio, situado entre la TDS y los modelos de umbral.

In this research we show the best efficient models in the evaluation of the recognition memory: First, a general mathematical model which underlies different data records ways. Second the election, organization and the presentation time of the stimulus is controlled experimentally. Third, we show the multilevel analysis for the rating scales, and a ROC and z-ROC distribution for the discrimination between TDS models and the threshold models. The results agree mainly with a TDS model when the stimuli are high frequency words, a model of threshold (or unequalvariance) when the stimuli are open class words, whereas the low frequency words occupy an intermediate place located between the TDS model and the threshold model.

Actitudes hacia la conservación del Medio Ambiente de parte de padres de familia, docentes y estudiantes de la zona urbana y rural de Belén 2008 / Rural and urban parents, teachers and student's attitudes towards environment conservation in Belen 2008

El estudio descriptivo comparativo transeccional buscó determinar si existen diferencias significativas en las actitudes hacia la conservación ambiental en docentes, padres de familia y alumnos de educación secundaria del distrito de Belén zona urbana con respecto a los de la rural. Trabajó en una muestra de 773 sujetos, 115 del área rural y 658 del área urbana; tres instituciones educativas del área rural y tres del área urbana. Utilizando la observación indirecta y reactiva como técnica, aplicando una escala tipo Likert de 50 ítems, que luego de ser adpatada a las características y naturaleza de los sujetos se valoraron los componentes cognitivo, reactivo o conductual y afectivo de sus actitudes. Según los resultados los sujetos muestran valores por encima de la media escalar en los tres componentes de las actitudes hacia la conservación ambiental ubicándose mayoritariamente en el nivel de aceptación; los padres de familia y estudiantes rurales alcanzaron puntajes ligeramente más altos que los urbanos; los docentes urbanos obtuvieron la media más alta en comparación con los rurales. Conclusión: existen diferencias estadísticamente significativas entre las actitudes generales y en los componentes reactivo y afectivo hacia la conservación ambiental de docentes urbanos con respecto a los rurales; y en el componente reactivo de los padres de familia rurales con respecto a los urbanos.

The objective of this descriptive transectional research was to find out whether the attitudes towards environment conservation in Belen District's urban area in parents, teachers and students of secondary school was significantly of those in rural area. The reaearch had 773 samples 115 in the rural area and 658 in the urban area, as well as 3 school in rural area and three in the urban area. direct and reactive observation was used as a technique: the contextualized Likert scale of 50 item was adapted to the characteristics and nature of the subjects. The cognitive, reactive and affective attitudes of the samples were valued.According the results, the subjects show values on top of the media in the three components of the attitudes towards environment conservation, which mean a level of acceptation. tehe rural area parents ans students scored slightly higher than those in rural ones. Conclusion: statistical sgnificant differences exist between general attitudes and the reactive and effective components towards environment conservation of urban teachers in comparison to rural ones, and in the reactive component of rural parents in comparison to urban ones.

Phylotyping and functional analysis of two ancient human microbiomes.

BACKGROUND: The Human Microbiome Project (HMP) is one of the U.S. National Institutes of Health Roadmap for Medical Research. Primary interests of the HMP include the distinctiveness of different gut microbiomes, the factors influencing microbiome diversity, and the functional redundancies of the members of human microbiotas. In this present work, we contribute to these interests by characterizing two extinct human microbiotas. METHODOLOGY/PRINCIPAL FINDINGS: We examine two paleofecal samples originating from cave deposits in Durango Mexico and dating to approximately 1300 years ago. Contamination control is a serious issue in ancient DNA research; we use a novel approach to control contamination. After we determined that each sample originated from a different human, we generated 45 thousand shotgun DNA sequencing reads. The phylotyping and functional analysis of these reads reveals a signature consistent with the modern gut ecology. Interestingly, inter-individual variability for phenotypes but not functional pathways was observed. The two ancient samples have more similar functional profiles to each other than to a recently published profile for modern humans. This similarity could not be explained by a chance sampling of the databases. CONCLUSIONS/SIGNIFICANCE: We conduct a phylotyping and functional analysis of ancient human microbiomes, while providing novel methods to control for DNA contamination and novel hypotheses about past microbiome biogeography. We postulate that natural selection has more of an influence on microbiome functional profiles than it does on the species represented in the microbial ecology. We propose that human microbiomes were more geographically structured during pre-Columbian times than today.

New diseases derived or associated with the tight junction.

The space between neighboring epithelial cells is sealed by the tight junction (TJ). When this seal is leaky, such as in the proximal tubule of the kidney or the gallbladder, substances may cross the epithelium between the cells (paracellular pathway). Yet, when TJs are really hermetic, as is the case in the epithelium of the urinary bladder or the colon, substances can mainly cross the epithelium through the transcellular pathway. The structure of the TJ involves (so far) some 50-odd protein species. Failure of any of these components causes a variety of diseases, some of them so serious that fetuses are not viable. A fast-growing number of diseases are recognized to depend or involve alterations in the TJ. These include autoimmune diseases, in which intestinal TJs allow the passage of antigens from the intestinal flora, challenging the immune system to produce antibodies that may cross react with proteins in the brain, thyroid gland or pancreas. TJs are also involved in cancer development, infections, allergies, etc. The present article does not catalogue all TJ diseases known so far, but describes one of each type as illustration. It also depicts the efforts being made to find pharmaceutical agents that would seal faulty TJs or release their grip to allow for the passage of large molecules through the upper respiratory and digestive tracts, such as insulin, thyroid, appetite-regulatory peptide, etc.

[Prevalence and severity of domestic violence among pregnant women, Mexico]. / Prevalencia y severidad de la violencia contra mujeres embarazadas, México.

OBJECTIVES: To determine whether pregnancy is a risk factor for domestic violence and to compare prevalence and severity of violence reported by women before and during pregnancy. METHODS: There were interviewed 468 women in the third trimester of pregnancy who were seen during prenatal visits at public clinics in the state of Morelos, Mexico. Emotional, physical and sexual violence were investigated. A severity index was built up. Logistic regression analysis was applied in order to identify the main variables associated to domestic violence during pregnancy. RESULTS: The prevalence of domestic violence did not change significantly before and during pregnancy (32%). The prevalence of each type of violence remained the same. About 27% of women who reported violence during pregnancy did not have experience it before, and a comparable proportion had experienced violence before but not during pregnancy. The severity of emotional violence significantly increased during pregnancy (compared to the previous year) whereas the severity of physical violence decreased. Variables most clearly related to violence during pregnancy were: couple's past history of child abuse; women witnessing domestic violence during childhood; and violence in the year before pregnancy. Several risk scenarios were identified, which could be helpful for health care providers. CONCLUSIONS: The results showed that emotional violence is more prevalent than physical and sexual violence, allowing for a better understanding of this phenomenon.

Prevalencia y severidad de la violencia contra mujeres embarazadas, México / Prevalence and severity of domestic violence among pregnant women, Mexico

OBJETIVOS: Determinar si el embarazo es un factor de riesgo o un factor de protección frente a la violencia doméstica y comparar la prevalencia y severidad de la violencia que sufren las mujeres embarazadas antes y durante el embarazo. MÉTODOS: Encuesta realizada a una muestra de 468 mujeres atendidas en consulta prenatal en su tercer trimestre de embarazo por los servicios de la Secretaría de Salud del estado de Morelos (México). Se exploró violencia emocional, física y sexual. Se construyó un índice para valorar la severidad. Se identificaron las variables más asociadas a la violencia durante el embarazo. RESULTADOS: La prevalencia de violencia total no cambió significativamente antes y durante el embarazo (32 por ciento). La prevalencia de cada uno de los tres tipos de violencia se mantuvo asimismo sin cambios. El 27 por ciento de las mujeres que tuvieron violencia durante el embarazo no la tuvieron antes del mismo; una proporción equivalente tuvieron violencia antes del embarazo pero no durante el mismo. La severidad de la violencia emocional se incrementó significativamente durante el embarazo (en comparación con el año previo), mientras que la severidad de la violencia física disminuyó. Variables asociadas a la violencia durante el embarazo: violencia en la infancia de la pareja; ; que la mujer haya presenciado violencia en casa durante su infancia; y violencia en el año previo al embarazo. Se presentan diversos escenarios de riesgo útiles para los prestadores de servicios. CONCLUSIONES: La violencia emocional durante el embarazo predomina por encima de la violencia fisica y sexual. Diferenciarlas contribuye a esclarecer la complejidad del fenómeno.

Risks for abuse against pregnant Hispanic women: Morelos, Mexico and Los Angeles County, California.

BACKGROUND: Although violence against women is gaining international attention as a prevention priority, little is known about how risks differ across countries. METHODS: A comparative study of violence against pregnant Mexican women in Morelos, Mexico, and Latina women in Los Angeles County, California, United States. In 1998 and 1999, women in prenatal clinics were interviewed about psychological abuse and sexual and physical violence by their partner, during and the 1 year prior to the index pregnancy. The overall response rate for Morelos was 99%, with a sample size of 914; Los Angeles County had a response rate of 96.9%, with a sample size of 219. RESULTS: Women in Morelos reported a higher prevalence of violence compared to women in the California (14.8% v 11.9%, respectively). A partner aged <20 years was associated with increased violence in both countries, but the association of violence with other socioeconomic factors differed by country. For example, employed women had higher odds of violence in California but lower odds in Morelos. Women who experienced violence during both the year prior to pregnancy and as a child were more than 25 times more likely to be abused during pregnancy than women not reporting this type of abuse. CONCLUSION: The identification of factors associated with violence against women, especially as they differ by culture and ethnicity, will help clinicians to better identify victims and to design and implement culturally appropriate prevention programs.

Violence against women in Mexico: a study of abuse before and during pregnancy.

OBJECTIVE: We identified the prevalence and types of violence experienced by pregnant women, the ways victimization changed during pregnancy from the year prior to pregnancy, and factors associated with violence during pregnancy. METHODS: We interviewed 914 pregnant women treated in health clinics in Mexico about violence during and prior to pregnancy, violence during childhood and against their own children, and other socioeconomic indicators. RESULTS: Approximately one quarter of the women experienced violence during pregnancy. The severity of emotional violence increased during pregnancy, whereas physical and sexual violence decreased. The strongest predictors of abuse were violence prior to pregnancy, low socioeconomic status, parental violence witnessed by women in childhood, and violence in the abusive partner's childhood. The probability of violence during pregnancy for women experiencing all of these factors was 61%. CONCLUSIONS: Violence is common among pregnant women, but pregnancy does not appear to be an initiating factor. Intergenerational violence is highly predictive of violence during pregnancy.

Prevalence of infection, mean worm burden and degree of worn aggregation as determinants of prevalence of disease due to intestinal helminths

Theoretical predictions of disease prevalence due to helminth infections based upon a simple probabilistica model which considers the infection prevalence, the mean worm urden and the degree of worm aggregation are presented. A numerical reappraisal of the likely estimates of the degree of aggregation based upon maximun likelihood estimates of the negative binomial distribution is presented. The prevalence of disease shows a positive relationship with the mean worm burden. This association is hyperbolic when helminth parasites are severely aggregated but is s-shaped when helminth parasites tend to be oversidpersed. The prevalence of disease decreases with the degree of worm aggregation whem the values of the mean intensity are low; as the mean intensity increases this association becomes positive. The relationship between prevalence of disease and prevalence of infection is hyperbolic for severe degrees of parasite aggregation and is s-shaped for intermediate degrees of aggregation. However, if the mean intesnsity is low and the degree of aggreation is high there could be a negative raltionship between the prevalence of disease due to helminth parasites is feasible for determined ranges of values of the infection prevalence, mena intensity and the degree of worm clumping

El grado de agregación de Ascaris lumbricoides según grupos de edad, después de una intervención antihelmíntica de masas / The degree of age-aggregation of Ascaris lumbricoides in a community after a mass antihelminthic intervention

Objetivo. Descubrir la heterogeneidad de la reinfección por Ascaris lumbricoides según grupos de edad, en distintos intervalos, después de un primer tratamiento antihelmíntico masivo. Material y métodos. A partir de datos de la prevalencia e intensidad de la infección por A. lumbricoides obtenidos en un estudio epidemiológico de ascariasis, realizado en Coatzacoalcos, Veracruz, México, se deriva el grado de agregación por medio del método de máxima verosimilitud, asumiendo una distribución binomial negativa del parásito en el huésped. Resultados. Se muestra que la distribución del parásito en el huésped es distinta en el ámbito poblacional que en el de grupos de edad, que la recuperación de la infección no es uniforme; y que la dinámica de asociación huésped-parásito exhibe una marcada desestabilización de su equilibrio endémico después de una primera intervención de masas. Conclusiones. Lo anterior sugiere que existe una alta variabilidad en la agregación entre los distintos grupos de edad y, por tanto, la infección y la reinfección son heterogéneas respecto a la edad. Después de la desestabilización del equilibrio endémico, los estados que alcanza el sistema huésped-parásito son transitorios. Dada la heterogeneidad de la infección, los tratamientos selectivos parecen ser la estrategia más adecuada para disminuirla

Objective. The degree of aggregation is determined for the whole population and for different age-specific strata and is used for assessing the reinfection rate after a mass antihelminthic chemotherapeutic intervention. Material and methods. The degree of aggregation of Ascaris lumbricoides is derived from prevalence and intensity of infection data obtained from an epidemiological study of ascariasis carried out in Coatzacoalcos, Veracruz, México by means of maximum likelihood estimation of the negative binomial distribution. Results. The results show that the distribution of the parasite for the whole population differs from the distribution of the parasite within each age-specific stratum; the reinfection rate is not uniform; the dynamics of the hostparasite association exhibits a clear destabilization of its endemic equilibrium after a first round of mass treatment.Conclusions. It is suggested that the aggregation among the different age-groups is highly variable and hence the infection and reinfection rates are heterogeneous with regard to age; these states of the host-parasite system are transient. Given the heterogeneity of the infection, the selective treatment seems to be the most adequate strategy to diminish helminth infection rates.