Seasonal variations in spatial usage by the estuarine dolphin, Sotalia guianensis (van Bénéden, 1864) (Cetacea; Delphinidae) at its southern limit of distribution.

The use of space by the resident population of estuarine dolphins (Sotalia guianensis) in Norte Bay, southern Brazil was studied by boat surveys between 2000 and 2003. Data such as the geographical position and group size was collected at 5-minute intervals using focal-group sampling. The distribution and seasonal and daily group home-ranges were estimated using a GIS (Geographic Information System) environment. The dolphins did not use the area homogeneously, restricting their activities to a well-defined area located in the western part of the bay, while the use of the eastern part was not observed. A discrepancy between the Environment Protection Area of Anhatomirim, created especially to protect this population and the distribution of the dolphins was observed. Seasonal group home-range varied both qualitatively and quantitatively among the four consecutive seasons analyzed. The dolphins tended to use a larger area in cold seasons, when apparently the abundance of major prey items is lower. Core areas of intense use were identified, and also varied seasonally. These core areas may be regarded as critical habitats and require special legislation and control. The mean daily group home-range did not differ statistically among seasons. The present study corroborates a spatially strict residency pattern of the estuarine dolphin in highly productive coastal ecosystems.

Seasonal variations in spatial usage by the estuarine dolphin, Sotalia guianensis (van Bénéden, 1864) (Cetacea; Delphinidae) at its southern limit of distribution

The use of space by the resident population of estuarine dolphins (Sotalia guianensis) in Norte Bay, southern Brazil was studied by boat surveys between 2000 and 2003. Data such as the geographical position and group size was collected at 5-minute intervals using focal-group sampling. The distribution and seasonal and daily group home-ranges were estimated using a GIS (Geographic Information System) environment. The dolphins did not use the area homogeneously, restricting their activities to a well-defined area located in the western part of the bay, while the use of the eastern part was not observed. A discrepancy between the Environment Protection Area of Anhatomirim, created especially to protect this population and the distribution of the dolphins was observed. Seasonal group home-range varied both qualitatively and quantitatively among the four consecutive seasons analyzed. The dolphins tended to use a larger area in cold seasons, when apparently the abundance of major prey items is lower. Core areas of intense use were identified, and also varied seasonally. These core areas may be regarded as critical habitats and require special legislation and control. The mean daily group home-range did not differ statistically among seasons. The present study corroborates a spatially strict residency pattern of the estuarine dolphin in highly productive coastal ecosystems.

A utilização espacial pela população residente de botos-cinza, Sotalia guianensis, na Baía Norte de Santa Catarina, Sul do Brasil, foi estudada por meio de saídas de barco realizadas entre 2000 e 2003. Dados como posição geográfica (GPS) e tamanho de grupo foram obtidos utilizando-se o método de grupo focal. A distribuição e a área de vida diária e sazonal do grupo foram estimadas por um SIG (Sistema de Informações Geográficas). O uso do espaço pelos botos foi heterogêneo, restringindo suas atividades a uma área bem definida, localizada na parte oeste da baía, enquanto a utilização do lado leste não foi observada. Observou-se uma discrepância entre a distribuição dos botos e a Area de Proteção Ambiental de Anhatomirim, criada especialmente para proteger esta população. A área de vida sazonal do grupo variou tanto qualitativamente como quantitativamente nas quatro estações do ano consecutivas estudadas. Os botos tenderam a utilizar uma área maior nas estações frias do ano, quando a abundância de suas presas potenciais parece ser menor. Identificaram-se áreas de maior concentração de indivíduos, que também tiveram variação sazonal. Estas áreas de concentração podem ser consideradas hábitats críticos e exigem controle e legislação especial. Não houve uma diferença sazonal significativa nas áreas de vida diária do grupo de botos nas diferentes estações do ano estudadas. Os resultados deste trabalho apontam para um padrão de residência espacialmente restrita de S. guianensis em ecossistemas costeiros de grande produtividade.

The HIV-1 Nef protein: how an AIDS pathogenetic factor turns to a tool for combating AIDS.

Nef is one of the six regulatory proteins coded by the Human Immunodeficiency Virus (HIV)-1 and -2, and by the Simian Immunodeficiency Virus (SIV). Accumulating experimental evidences indicate that Nef is required for the optimal infectivity of HIV viral particles, and that it plays a critical role in the AIDS pathogenesis progressing. We previously cloned and sequenced a functionally defective HIV-1 genome (F12HIV-1) whose nef gene showed a rather unusual feature, i.e. its expression blocks the HIV-1 release by interfering with the viral assembling/release. Such a striking phenotype appeared to be the result of three amino acid substitutions, and coupled with the loss of the most part of the Nef functions described for the wild type counterpart. The F12Nef properties encouraged the designing of new strategies of anti HIV-1 gene therapy we afforded by recovering an inducible lentivirus vector expressing F12Nef as the cytoplasmic domain of a transmembrane fusion protein including a selectable marker (i.e. the Nerve Growth Factor receptor) as the ecto- and transmembrane domains. As expected, the expression of such a chimeric protein resulted in a potent protection of transduced cells from the HIV-1 spread. In sum, and surprisingly enough, we generated a reagent effectively counteracting the HIV-1 replication through the combination of a slightly mutated AIDS pathogenetic factor together with a lentivirus vector, i.e. the result of artifactual modifications of the HIV-1 genome.

[Seronegative hashitoxicosis in patient with rheumatoid arthritis]. / Hashitossicosi sieronegativa in paziente con artrite reumatoide.

Hashimoto's thyroiditis is known to occur in conjunction with other autoimmune disorders including rheumatoid arthritis. We describe herein a patient with long before-onset seronegative rheumatoid arthritis who developed Hashimoto's thyroiditis and hyperthyroidism without serologic evidence of thyroglobulin, microsomal and/or anti-TSH receptor antibodies. The occurrence of these autoimmune diseases in individual patients suggests an imbalance in immune function which effects more than one organ system. The predisposition to this spectrum of autoimmune diseases may be genetically determined, with specific HLA haplotypes associated with a variety of autoimmune diseases. The case of this patient provides the demonstration that intrathyroidal lymphocytes in autoimmune thyroid disorders and T-lymphocytes in the synovium are responsible for mediating the glandular destruction in Hashimoto disease and intraarticular lesions in rheumatoid arthritis, since the disorders can exist without evidence of a systemic immune response.