RESUMO
The term 'endemic parkinsonism' refers to diseases that manifest with a dominant parkinsonian syndrome, which can be typical or atypical, and are present only in a particular geographically defined location or population. Ten phenotypes of endemic parkinsonism are currently known: three in the Western Pacific region; two in the Asian-Oceanic region; one in the Caribbean islands of Guadeloupe and Martinique; and four in Europe. Some of these disease entities seem to be disappearing over time and therefore are probably triggered by unique environmental factors. By contrast, other types persist because they are exclusively genetically determined. Given the geographical clustering and potential overlap in biological and clinical features of these exceptionally interesting diseases, this Review provides a historical reference text and offers current perspectives on each of the 10 phenotypes of endemic parkinsonism. Knowledge obtained from the study of these disease entities supports the hypothesis that both genetic and environmental factors contribute to the development of neurodegenerative diseases, not only in endemic parkinsonism but also in general. At the same time, this understanding suggests useful directions for further research in this area.
Assuntos
Transtornos Parkinsonianos , Humanos , Transtornos Parkinsonianos/epidemiologia , Transtornos Parkinsonianos/genética , Guadalupe/epidemiologia , Europa (Continente) , Fenótipo , BiologiaRESUMO
Recent marsupials include about 280 species divided into 18 families and seven orders. Approximately 200 species live in Australia/New Guinea. The remaining species inhabit South America with some of these secondarily ranging into North America. In this study, we examine marsupial relationships and estimate their divergences times using complete mitochondrial (mt) genomes. The sampling, which includes nine new mtDNAs and a total number of 19 marsupial genomes, encompasses all extant orders and 14 families. The analysis identified a basal split between Didelphimorphia and remaining orders about 69 million years before present (MYBP), while other ordinal divergences were placed in Tertiary times. The monotypic South American order Microbiotheria (Dromiciops gliroides, Monito del Monte) was solidly nested among its Australian counterparts. The results suggest that marsupials colonized Australia twice from Antarctica/South America and that the divergence between Microbiotheria and its Australian relatives coincided with the geological separation of Antarctica and Australia. Within Australia itself, several of the deepest divergences were estimated to have taken place close to the Eocene/Oligocene transition.
Assuntos
Marsupiais/genética , Filogenia , Animais , DNA Mitocondrial/genética , Variação Genética , Marsupiais/classificação , Proteínas Mitocondriais/genética , América do Sul , Fatores de TempoRESUMO
Considerando que existe una gran cantidad de substancias químicas potencialmente tóxica en el ambiente, lugar de trabajom y en la farmacia, es importante que los médicos estén alertas a estos principios elementales para diagnosticar la neurotoxicidad. Muchos enfermos de afecciones neurológicas de origen tóxico son encuentros casuales y las epidemias sonraras. Estos informes genuinos tienen gran valor cuando se identifica la toxina y pueden dar lugar a la comprensión de los mecanismos de alteración del sistema nervioso producido químicamente