16 research outputs found

    Neuregulin 1 and susceptibility to schizophrenia

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    To access full text version of this article. Please click on the hyperlink "View/Open" at the bottom of this pageThe cause of schizophrenia is unknown, but it has a significant genetic component. Pharmacologic studies, studies of gene expression in man, and studies of mouse mutants suggest involvement of glutamate and dopamine neurotransmitter systems. However, so far, strong association has not been found between schizophrenia and variants of the genes encoding components of these systems. Here, we report the results of a genomewide scan of schizophrenia families in Iceland; these results support previous work, done in five populations, showing that schizophrenia maps to chromosome 8p. Extensive fine-mapping of the 8p locus and haplotype-association analysis, supplemented by a transmission/disequilibrium test, identifies neuregulin 1 (NRG1) as a candidate gene for schizophrenia. NRG1 is expressed at central nervous system synapses and has a clear role in the expression and activation of neurotransmitter receptors, including glutamate receptors. Mutant mice heterozygous for either NRG1 or its receptor, ErbB4, show a behavioral phenotype that overlaps with mouse models for schizophrenia. Furthermore, NRG1 hypomorphs have fewer functional NMDA receptors than wild-type mice. We also demonstrate that the behavioral phenotypes of the NRG1 hypomorphs are partially reversible with clozapine, an atypical antipsychotic drug used to treat schizophrenia

    Principles Guidelines and Development of the Icelandic Model for the Prevention of Substance Use in Adolescents

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    Publisher's version (útgefin grein)El uso de sustancias por los adolescentes (i.e. el consumo de alcohol, tabaco, y otras drogas), persiste como un problema global, y se mantiene como un desafio para nuestras sociedades y autoridades de salud publica. Como respuesta a las altas tasas de uso de sustancias en adolescentes en los anos '90, en Islandia han sido pioneros en el desarrollo del Modelo Islandes Para la Prevencion Primaria del Uso de Substancias - un metodo basado en la teoria y evidencia cientifica que ha demostrado su efectividad en bajar los niveles de consumo en Islandia en los ultimos 20 anos. Para documentar este metodo e informar sobre los procesos basados-en-la-practica que puedan ayudar en establecer este modelo en otros paises, describimos esquematicamente en esta serie de dos partes la teoria, antecedentes, principios directrices del metodo, y los pasos centrales en la implementacion exitosa del modelo. En este articulo describimos los antecedentes y contexto necesarios, la orientacion teorica, el desarrollo del metodo, y brevemente revisamos los hallazgos y datos publicados. Adicionalmente, presentamos los cinco principios guia en los que se basa el metodo del Modelo de Prevencion Islandes para la prevencion del uso de sustancias en adolescentes, y discutimos la evidencia acumulada que apoya la efectividad del modelo. En el siguiente articulo, parte 2, identificamos y describimos procesos clave en el modelo y los diez pasos centrales de la implementacion efectiva y basada en la practica de este modelo.Peer reviewe

    Congenital cardiac malformations in Iceland from 1990 through 1999

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    To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldINTRODUCTION AND BACKGROUND: About 1% of live-born children have congenital malformations of the heart. The aim of our study was to investigate the incidence of such defects in children born in Iceland during a period of 10 years, extending from 1990 through 1999. MATERIALS AND METHODS: Information about the patients was obtained from medical records from two hospitals that cover the whole country, a private clinic of pediatric cardiologists, an echocardiography database, autopsy reports, and death certificates. We investigated the distribution of specific malformations, the age at diagnosis, the symptoms leading to the diagnosis, the source of referral, and treatment and quality of life. RESULTS: Between 1990 and 1999, there were 44,013 live births in Iceland, of which 740 patients were diagnosed with congenital cardiac malformations, accounting for 1.7% of the live-born children. The distribution was made up of 338 patients with ventricular septal defect (45.7%), 90 with atrial septal defect (12.2%), 85 with patency of the arterial duct (11.5%), 48 with pulmonary valvar stenosis (6.5%), 38 with a bicuspid aortic valve (5.1%), 28 with aortic coarctation (3.8%), 22 with tetralogy of Fallot (3.0%), 14 with transposed great arteries (1.9%), 11 with aortic stenosis (1.5%), 10 with atrioventricular septal defect and common atrioventricular orifice (1.4%), 9 with mitral valvar regurgitation (1.2%), 7 with sub-aortic stenosis (0.9%), and 5 with hypoplasia of the left heart (0.7%). Extracardiac anomalies were seen in 89 patients (12.0%). Chromosomal defects were seen in 36 patients, of whom 28 had Down's syndrome. DISCUSSION: The annual incidence of diagnosis of patients with congenital cardiac malformations increased during the period of study. This was noted for minor defects, but the incidence of the major anomalies did not alter. Our observed yearly incidence, at 1.7%, was higher than noted in a previous study covering the years 1985 through 1989, and is also higher than in other population-based studies. The most likely explanation is the fact that access to pediatric cardiologists in Iceland is very good. Diagnosis, registration, and follow-up are conducted by only a few cardiologists, and take place at a single center for pediatric cardiology
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