Resumo Objetivo Comparamos a eficácia de dois dispositivos de amostragem, o amostrador Surber e a Rede-D, comumente utilizados na análise da estrutura da fauna de invertebrados em programas de biomonitoramento. Esses programas utilizam a resposta dos invertebrados bentônicos para avaliar as mudanças nos ecossistemas aquáticos porque respondem rapidamente às variações espaciais e temporais. No entanto, a falta de consenso sobre o melhor método de amostragem da fauna pode reduzir a qualidade desses estudos. Métodos Avaliamos ambos os dispositivos em quatro trechos estruturalmente diferentes de riachos, dois em locais com vegetação ripária preservada e dois ocorrendo em locais com várias alterações antrópicas. Repetimos a análise na estação seca de dois anos consecutivos. Resultados Os dois amostradores foram igualmente eficazes na análise da fauna bentônica e sensíveis o suficiente para identificar variações espaciais e temporais na estrutura desta fauna, influenciada pela presença ou ausência de vegetação ripária, pela posição do trecho com essa vegetação (a montante ou jusante do trecho sem vegetação) e pelas características do substrato. Conclusões A estrutura da fauna analisada foi semelhante para os dois amostradores, mas consideramos o uso do Surber mais vantajoso e efetivo por amostrar um menor número de indivíduos, reduzindo o tempo de processamento e identificação no laboratório, e por permitir uma melhor definição da área amostrada.

Abstract Aim We compared the effectiveness of two sampling devices, the Surber sampler and the D-frame net, commonly used in the analysis of invertebrate fauna structure in biomonitoring programs. These programs use the response of benthic invertebrates to assess changes in aquatic ecosystems because they respond quickly to spatial and temporal variations. However, the lack of consensus on the best method of sampling the fauna may reduce the quality of these studies. Methods We evaluated both devices in four structurally different reaches of streams, two in places with preserved riparian vegetation and two occurring in places with many anthropic disturbances. We repeated the analysis at the dry season of two consecutive years. Results The two samplers were equally effective in analyzing the benthic fauna and sensitive enough to identify spatial and temporal variation in the structure of this fauna, influenced by the presence or absence of riparian vegetation, by the position of the reach with this vegetation (upstream or downstream of the reach without vegetation) and the characteristics of the substrate. Conclusions The analyzed fauna structure was similar for the two samplers, but we consider the use of Surber more advantageous and effective because it collects a smaller number of individuals, reducing the time of processing and identifying in the laboratory, and allows a better definition of the area sampled.

Abstract: Albinism is a genetic condition caused by an autosomal recessive gene that affects normal pigmentation in animals. In Neotropical freshwater fish fauna, albinism cases are extremely rare, with only 14 species recorded among more than 6000 described. Here, we describe the first reported case of albinism in the South American catfish Imparfinis mirini. The albino fish was collected in July 2016 with a seine net in a stream in southeast Brazil. Although albinism can decrease the chance of fish survival, the cryptic and nocturnal habits of this species and the low amount of piscivorous fish and birds in the stream may have favored its growth. Two possible explanations for the appearance of the albino fish are discussed: a genetic disorder caused by heavy metal contamination and the high endogamy rate in the fish population which could increase the chances of appearing deleterious genes.

Resumen: El albinismo es una condición genética causada por un gen autosómico recesivo que afecta a la pigmentación normal en los animales. En la fauna de peces de agua dulce neotropicales, los casos de albinismo son extremadamente raros, con solo 14 especies registradas entre más de 6000 descritas. Se expone el primer caso documentado de albinismo en el bagre sudamericano Imparfinis mirini. El pez albino fue recolectado en julio de 2016 con una red de cerco en un arroyo en el sureste de Brasil. Aunque el albinismo puede disminuir la probabilidad de supervivencia de los peces, los hábitos crípticos y nocturnos de esta especie y la baja cantidad de peces y aves piscívoras en los arroyos pueden haber favorecido su crecimiento. Se examinaron 2 posibles explicaciones para esta condición: un trastorno genético causado por la contaminación por metales pesados y la alta tasa de endogamia en la población de peces, que podría aumentar las posibilidades de aparición de genes deletéreos.

ABSTRACT Immunological and clinical findings suggestive of some immune dysfunction have been reported among HIV-exposed uninfected (HEU) children and adolescents. Whether these defects are persistent or transitory is still unknown. HEU pediatric population at birth, 12 months, 6-12 years were evaluated in comparison to healthy age-matched HIV-unexposed controls. Plasma levels of LPS, sCD14, cytokines, lymphocyte immunophenotyping and T-cell receptor excision circles (TREC) were assessed. HEU and controls had similar LPS levels, which remained low from birth to 6-12 years; for plasma sCD14, IL-2, IL-6, IL-7, IL-10, IL-12p70, IL-13, IL-17, IFN-γ, TNF-α, G-CSF, GM-CSF and MCP-1, which increased from birth to 12 months and then decreased at 6-12 years; and for TREC/106 PBMC at birth in HEU and controls. By contrast, plasma MIP-1β levels were lower in HEU than in controls (p=0.009) at 12 months, and IL-4 levels were higher in HEU than controls (p=0.04) at 6-12 years. Immune activation was higher in HEU at 12 months and at 6-12 years than controls based on frequencies of CD38+HLA-DR+CD8+T cells (p=0.05) and of CD38+HLA-DR+CD4+T cells (p=0.006). Resting memory and activated mature B cells increased from birth to 6-12 years in both groups. The development of the immune system in vertically HEU individuals is comparable to the general population in most parameters, but subtle or transient differences exist. Their role in influencing clinical incidences in HEU is unknown.

Ethnic origin, genetics, gender and environmental factors have been shown to influence some immunologic indices, so that development of reference values for populations of different backgrounds may be necessary. We have determined the distribution of lymphocyte subsets in healthy Brazilian individuals from birth to adulthood. Lymphocyte subsets were determined using four-colour cytometry in a cross-sectional study of 463 human immunodeficiency virus-unexposed children and adults from birth through 49 years of age. Lymphocyte subsets varied according to age, as previously observed in other studies. However, total CD4+ T cell numbers were lower than what was described in the Pediatric AIDS Clinical Trials Group P1009 (PACTG P1009), which assessed an American population of predominantly African and Hispanic backgrounds until the 12-18 year age range, when values were comparable. Naïve percentages and absolute values of CD8+ T cells, as assessed by CD45RA expression, were also lower than the PACTG P1009 data for all analysed age ranges. CD38 expression on both CD4+ and CD8+ T cells was lower than the PACTG P1009 values, with a widening gap between the two studies at older age ranges. Different patterns of cell differentiation seem to occur in different settings and may have characteristic expression within each population.