The objective of this research was to evaluate the validity of Hodkinson’s Abbreviated Mental Test (AMT) in screening for dementia and to identify the optimum cut‐off point to use in a prevalence ...survey. The study included two groups of persons: (i) a random sample of 183 individuals selected from census data, 96 of whom completed the study and (ii) another 36 persons with dementia were selected from a hospital outpatients department by sampling consecutive cases. The DSM‐IV criteria were used as the ‘gold standard’ to establish a diagnosis of dementia. The AMT was administered to the 132 participants who subsequently underwent independent clinical evaluation. In the community sample, 11 persons were diagnosed with dementia and 85 without. In the total sample, a score of 7 maximizes the efficacy of the test. The sensitivity for this cut‐off point is 91.5% (78.7–97.2%) and the specificity is 82.4% (72.2–89.5%). A score of 9 gives 100% sensitivity, but the proportion of false positives rises to 66%. Our results are consistent with other studies and suggest that the AMT is a valid instrument for use in screening for dementia in populations similar to the one in this study.
We report a 61-year-old alcoholic man who presented with subacute physical deterioration and severe dysarthria. MRI, suggestive of corpus callosum demyelination with associated white matter ...involvement in both cerebral hemispheres, indicated the diagnosis of Marchiafava-Bignami disease. During his stay in hospital the patient showed remarkable improvement, and was discharged 22 days after admission. On MRI 2 months later, the extracallosal lesions had disappeared. This case raises questions about some previous ideas on this disease, such as the prognosis of its acute forms and the significance of the extracallosal lesions seen on neuroimaging.
¿El cambio global modificará la distribución de la planta Anadenanthera colubrina (Fabales: Fabaceae), especie clave de los bosques tropicales secos? Introducción: Los Bosques Tropicales ...Estacionalmente Secos (BTES) son unos de los ecosistemas terrestres más amenazados del planeta como consecuencia del cambio global. Estos bosques albergan una alta biodiversidad y proporcionan una amplia gama de servicios ecosistémicos, por lo que su conservación es una prioridad a nivel mundial. El cambio climático y el cambio en los usos del suelo están afectando la distribución de las especies. Objetivo: El objetivo de este trabajo fue estudiar la distribución potencial de una especie representativa de BTES (Anadenanthera colubrina) en el núcleo del Piedemonte subandino argentino y evaluar los efectos del cambio en los usos del suelo y del cambio climático sobre su distribución. Métodos: La distribución actual y futura de A. colubrina fue modelada con Maxent, utilizando 49 puntos de presencia y 20 variables. Los efectos del cambio climático se estimaron en cuatro escenarios que difieren en los niveles de temperatura y concentración de dióxido de carbono. Los efectos del cambio en el uso del suelo se estimaron descontando el área deforestada hasta el 2017 a la distribución actual y futura de la especie. Resultados: La distribución actual de A. colubrina representa un 18% del Noroeste Argentino. Los cambios en el uso del suelo produjeron una disminución del 25% del área de distribución actual y el cambio climático probablemente causará una retracción al Este y una expansión hacia el oeste y sur de su distribución. El efecto sinérgico del cambio en el uso del suelo y el cambio climático podría producir una pérdida del 63% considerando el peor escenario de cambio climático. Conclusiones: Nuestros datos demuestran el rol fundamental de los estudios de distribución para evaluar los efectos de las actividades antrópicas. Los cambios en los usos del suelo y el cambio climático podrían tener un efecto negativo y sinérgico sobre la distribución de A. colubrina. La posible expansión del núcleo Piedemonte de SDTF hacia el oeste y el sur de la región no estaría limitada por cambios en el uso del suelo, aunque las cadenas montañosas podrían actuar como barreras orográficas y limitar la expansión. Palabras clave: cambio climático, conservación, rango geográfico, cambios en los usos del suelo, modelos de distribución de especies. Introduction: Seasonally dry tropical forests (SDTF) are one of the most threatened terrestrial ecosystems on the planet as a consequence of global change. They harbor high biodiversity and provide a wide range of ecosystem services; therefore, their conservation is a priority worldwide. Climate warming, as well as land use patterns, are leading to species distribution range shifts. Objective: The objective of this work was to study the current and future potential distribution of a SDTF representative tree species (Anadenanthera colubrina) in the Argentinian Sub Andean Piedmont nucleus and to assess the effects of land use and climate changes. Methods: Current and future potential distribution was modeled with Maxent, using 49 presence points and 20 variables. Climate change effects were estimated in four different temperature and carbon dioxide concentration scenarios. Land use changes were determined subtracting the deforested area until 2017 to the current and future potential distribution of the species. Results: A. colubrina current distribution represents 18% of Northwestern Argentina. Land use changes decreased almost 25% of it and climate change will probably cause a retraction in the East and a slight expansion towards the West and South of the current distribution. The synergistic effect of land use and climate change projected to the worst scenario would reduce 63% of its current distribution. Conclusions: Our data demonstrate the central role of distribution range studies to assess the effects of anthropic activities. Climate change and land use change would have a negative and synergistic effect on the distribution of A. colubrina. Although a possible expansion of the Sub Andean Piedmont nucleus of SDTF would occur, this expansion may be limited by the Sub Andean mountain range that could act as an orographic barrier. Key words: climate change, conservation, geographic range, land use change, species distribution models.
Wild species related to crops are a source of genes for improving crop tolerance of biotic and abiotic stresses. Vasconcellea quercifolia and V. glandulosa are wild relatives of papaya (Carica ...papaya). They are the southernmost-distributed members of the genus and have traits related to tolerance of temperature and precipitation seasonality. Climate and land-use changes, however, are threatening their persistence. Our objectives were to identify priority ex situ conservation areas based on the potential distribution of both species in northwestern Argentina under global change scenarios. The potential distribution of Vasconcellea spp. was modeled using occurrence data and five bioclimatic non-correlated variables. Distribution range shifts were assessed in two climate change scenarios for the year 2050, considering land-use changes. Gap analysis methodology was applied, and conservation priorities were identified by an integrated approach of conservation strategies. Vasconcellea quercifolia has a wider habitat suitability area than V. glandulosa, and the effect of land- use change on distribution was higher for the former than latter species. Conversely, climate change would be more negative on V. glandulosa than V. quercifolia, and the synergic effect of both climate and land-use changes would be higher for V. quercifolia than V. glandulosa. According to gap analysis, both Vasconcellea spp. are high priority species for further germplasm collection. We identified priority areas for ex situ conservation.
Background: Between January 1993 and December 2003, 19 patients with familial prion diseases due to the D178N mutation were referred to the regional epidemiological registry for spongiform ...encephalopathies in the Basque Country in Spain, a small community of some 2 100 000 inhabitants. Methods: Ten further patients belonging to the same pedigrees were retrospectively ascertained through neurological or neuropathological records. In four of the patients, the diagnosis was confirmed by analysing DNA obtained from paraffin blocks. In this article, we report on the clinical, genetic, and pathological features of the 23 patients carrying the D178N mutation confirmed by genetic molecular analysis. Haplotyping studies suggest a founder effect among Basque born families, explaining in part this unusually high incidence of the D178N mutation in a small community. Only two patients (8%) lack familial antecedents. Results: We have observed a phenotypic variability even among homozygous 129MM patients. Our findings challenge the currently accepted belief that MM homozygosity in codon 129 is always related to a fatal familial insomnia (FFI) phenotype. Indeed, seven out of 17 patients with a 129MM genotype in this series presented with a Creutzfeldt-Jakob disease (CJD) clinicopathological picture. Conclusions: The considerable clinical and pathological overlapping observed among homozygous 129MM patients favours the view that FFI and CJD178 are the extremes of a spectrum rather than two discrete and separate entities. Other genetic or environmental factors apart from the polymorphism in codon 129 may play a role in determining the phenotypic expression of the D178N mutation in the PRNP gene.
The concept of limb-girdle muscular dystrophy (LGMD) is changing rapidly due to the advances in molecular genetics. Recently, seven different gene loci have been described, demonstrating that ...limb-girdle muscular dystrophy is a heterogeneous syndrome, which includes different diseases with a similar phenotype. In isolated populations which have little genetic exchange with neighbouring populations, an accumulation of cases may be found. We carried out an epidemiological study in Guipúzcoa, a small mountainous Basque province in northern Spain, and found the highest prevalence rate of LGMD described so far: 69 per million. Genetic studies demonstrated that 38 cases corresponded to the LGMD2A type, due to calpain-3 gene mutations. Only one patient with alpha-sarcoglycanopathy was found, and in 12 patients the genetic defect was not identified. Moreover, the particular calpain-3 mutation predominant in Basque chromosomes (exon 22, 2362AG-->TCATCT), has only been rarely found in the rest of the world. This observation strongly suggests a founder effect in the indigenous population of Guipúzcoa. The clinical characteristics of the patients with calpain-3 gene mutations were quite homogeneous and different from the other groups (sarcoglycanopathy and unknown gene defect), allowing for a precise clinical diagnostic. The disease onset was between the ages of 8 and 15 years, in most cases in the pelvic girdle, and the patients became wheelchair-bound between 11 and 28 years after onset. No pseudohypertrophy of calves or contractures were observed. No clear correlations were found between the nature and site of the mutation and the resulting phenotype.
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