Guido Mazzotti

Geographic patterns of genome admixture in Latin American Mestizos.

The large and diverse population of Latin America is potentially a powerful resource for elucidating the genetic basis of complex traits through admixture mapping. However, no genome-wide characterization of admixture across Latin America has yet been attempted. Here, we report an analysis of admixture in thirteen Mestizo populations (i.e. in regions of mainly European and Native settlement) from seven countries in Latin America based on data for 678 autosomal and 29 X-chromosome microsatellites. We found extensive variation in Native American and European ancestry (and generally low levels of African ancestry) among populations and individuals, and evidence that admixture across Latin America has often involved predominantly European men and both Native and African women. An admixture analysis allowing for Native American population subdivision revealed a differentiation of the Native American ancestry amongst Mestizos. This observation is consistent with the genetic structure of pre-Columbian populations and with admixture having involved Natives from the area where the Mestizo examined are located. Our findings agree with available information on the demographic history of Latin America and have a number of implications for the design of association studies in population from the region.

A Genomewide Admixture Map for Latino Populations

Admixture mapping is an economical and powerful approach for localizing disease genes in populations of recently mixed ancestry and has proven successful in African Americans. The method holds equal promise for Latinos, who typically inherit a mix of European, Native American, and African ancestry. However, admixture mapping in Latinos has not been practical because of the lack of a map of ancestry-informative markers validated in Native American and other populations. To address this, we screened multiple databases, containing millions of markers, to identify 4,186 markers that were putatively informative for determining the ancestry of chromosomal segments in Latino populations. We experimentally validated each of these markers in at least 232 new Latino, European, Native American, and African samples, and we selected a subset of 1,649 markers to form an admixture map. An advantage of our strategy is that we focused our map on markers distinguishing Native American from other ancestries and restricted it to markers with very similar frequencies in Europeans and Africans, which decreased the number of markers needed and minimized the possibility of false disease associations. We evaluated the effectiveness of our map for localizing disease genes in four Latino populations from both North and South America.

Challenges to reduce the ‘10/90 gap’: mental health research in Latin American and Caribbean countries

Objective:  To analyze the status of mental health research in 30 Latin American and Caribbean countries (LAC).

Improving mental and neurological health research in Latin America: a qualitative study

BackgroundResearch evidence is essential to inform policies, interventions and programs, and yet research activities in mental and neurological (MN) health have been largely neglected, particularly in low- and middle-income countries. Many challenges have been identified in the production and utilization of research evidence in Latin American countries, and more work is needed to overcome this disadvantageous situation. This study aims to address the situation by identifying initiatives that could improve MN health research activities and implementation of their results in the Latin American region.MethodsThirty-four MN health actors from 13 Latin American countries were interviewed as part of an initiative by the Global Forum for Health Research and the World Health Organization to explore the status of MN health research in low- and middle-income countries in Africa, Asia and Latin-America.ResultsA variety of recommendations to increase MN health research activities and implementation of their results emerged in the interviews. These included increasing skilled human resources in MN health interventions and research, fostering greater participation of stakeholders in the generation of research topics and projects, and engendering the interest of national and international institutions in important MN health issues and research methodologies. In the view of most participants, government agencies should strive to have research results inform the decision-making process in which they are involved. Thus these agencies would play a key role in facilitating and funding research. Participants also pointed to the importance of academic recognition and financial rewards in attracting professionals to primary and translational research in MN health. In addition, they suggested that institutions should create intramural resources to provide researchers with technical support in designing, carrying out and disseminating research, including resources to improve scientific writing skills.ConclusionFulfillment of these recommendations would increase research production in MN health in Latin American countries. This, in turn, will raise the profile of these health problems, and consequently will underscore the need of continued high-quality and relevant research, thus fostering a virtuous cycle in the decision-making process to improve MN health care.

Factores predictores de uso problemático de alcohol en personas atendidas en una sala de emergencia

RESUMEN Objetivos. Valorar el efecto predictivo de caracteristicas claves de pacientes atendidos en salas de emergencia para detectar casos de uso problematico de alcohol. Materiales y Metodos. La muestra de estudio estuvo constituida por 371 personas atendidas en el lapso de siete dias completos de enero de 2005 en el servicio de emergencia de un hospital publico de Lima, Peru. Se aplico un cuestionario demografico, el SIDUC/CICAD para uso reciente de sustancias psicoactivas en salas de emergencias (i.e., uso dentro de las seis horas previas a la atencion) y el AUDIT para uso problematico de alcohol en el ultimo ano. El analisis de regresion logistica simple y multivariada permitio valorar el efecto predictor de la edad, sexo, especialidad del servicio de atencion, presencia de dano fisico y el uso reciente de alcohol para detectar casos problematicos de su uso. Resultados. El odds de tener uso problematico de alcohol en los varones es 26 veces el odds de tener dicho problema entre las mujeres (p<0,001). El analisis estratificado por sexo y ajustado por edad y especialidad del servicio de emergencia, mostro que para los varones el uso reciente de alcohol estuvo fuertemente asociado con presentar uso problematico (OR=5,2; IC al 95%: 2,4-11,5; p<0,001), mientras que para las mujeres no se encontro dicha asociacion. Conclusiones. Se debe tamizar uso problematico de alcohol en aquellos varones con uso reciente de alcohol atendidos en salas de emergencia, para poder identificarlos y darles la oportunidad de recibir consejeria o un manejo medico adecuado.

Trastornos mentales en pacientes hospitalizadas en tratamiento con glucocorticoides

OBJETIVO. Estudiar la prevalencia de transtornos mentales en pacientes hospitalizadas en tratamiento con corticoides y sus correlaciones. METODO. Se estudio a 40 pacientes en tratamiento con corticoides mediante una encuesta que incluye preguntas sobre sueno, algunas partes del SCID (para examinar depresion, mania/hipomania y ansiedad), el Mini-Mental Status Examination y las pruebas de retencion de digitos directa e inversa. RESULTADOS. Al momento de la entrevista, la prevalencia de transtornos mentales en general fue 87.5 por ciento; depresion, 37.5 por ciento;mania/hipomania, 20 por ciento;ansiedad, 65 por ciento; falla cognitiva, 25 por ciento; falla en la retencion de digitos directa, 47.5 por ciento; falla en la retencion de digitos inversa, 60 por ciento; y alteraciones del sueno, 77.5 por ciento. El 12.5 por ciento de pacientes presento delirio p psicosis en algun momento de la corticoterapia. Las pacientes que recibieron >52 mg/dia de prednisona o su equivalente (ultimo cuartil de dosis) tuvieron menos prevalencia de transtornos mentales en general (p