346 research outputs found

    Childhood Adrenocortical Tumours: a Review

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    Childhood adrenocortical tumour (ACT) is not a common disease, but in southern Brazil the prevalence is 15 times higher than in other parts of the world. One hundred and thirty-seven patients have been identified and followed by our group over the past four decades. Affected children are predominantly girls, with a female-to-male ratio of 3.5:1 in patients below 4 years of age. Virilization alone (51.6%) or mixed with Cushing's syndrome (42.0%) was the predominant clinical picture observed in these patients. Tumours are unilateral, affecting both glands equally. TP53 R337H germline mutations underlie most childhood ACTs in southern Brazil. Epidemiological data from our casuistic studies revealed that this mutation has ~10% penetrance for ACT. Surgery is the definitive treatment, and a complete resection should always be attempted. Although adjuvant chemotherapy has shown some encouraging results, its influence on overall outcome is small. The survival rate is directly correlated to tumour size; patients with small, completely excised tumours have survival rates close to 90%, whereas in those patients with inoperable tumours and/or metastatic disease it is less than 10%. In the group of patients with large, excisable tumours, half of them have an intermediate outcome. Recent molecular biology techniques and genomic approaches may help us to better understand the pathogenesis of ACT, the risk of developing a tumour when TP53 R337H is present, and to predict its outcome. An ongoing pilot study consisting of close monitoring of healthy carriers of the TP53 R337H mutation - siblings and first-degree relatives of known affected cases - aims at the early detection of ACTs and an improvement of the cure rate

    Planting time for maximization of yield of vinegar plant calyx (Hibiscus sabdariffa L.)

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    Objetivou-se avaliar a produtividade de cálices de Hibiscus sabdariffa L., planta medicinal, em quatro épocas de plantio em Lavras M.G. Os tratamentos foram quatro épocas de plantio (18 de outubro; 15 de novembro; 18 de dezembro de 2001 e 15 de janeiro de 2002) e realizada uma colheita quando praticamente não existiam cálices em desenvolvimento, quase no final do ciclo da planta. Foram considerados os números de cálices por planta, as fitomassas frescas e secas dos cálices e a qualidade. Concluiu-se que a época de plantio influenciou o rendimento por planta e as fitomassas frescas e secas dos cálices, diferindo entre si pelo teste de Tukey a 5%. No plantio de outubro, houve maior rendimento (2.522 kg/ha), com produção de 5,24 vezes a mais em relação ao plantio do mês de janeiro (481 kg/ha). Os plantios nos meses de novembro e dezembro tiveram produções de 1.695 e 1.093 kg.ha-1 de cálices secos, respectivamente, e em relação ao mês de janeiro, a produção foi 3,52 e 2,27 vezes a mais.Deve-se realizar a colheita assim que os cálices estiverem maduros, a fim de preservar a qualidade

    The Fate of Carbon in Sediments of the Xingu and Tapajós Clearwater Rivers, Eastern Amazon

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    The Xingu and Tapajós rivers in the eastern Amazon are the largest clearwater systems of the Amazon basin. Both rivers have “fluvial rias” (i.e., lake-like channels) in their downstream reaches as they are naturally impounded by the Amazon mainstem. Fluvial rias are widespread in the Amazon landscape and most of the sedimentary load from the major clearwater and blackwater rivers is deposited in these channels. So far, little is known about the role of Amazon rias as a trap and reactor for organic sediments. In this study, we used organic and inorganic geochemistry, magnetic susceptibility, diatom, and pollen analyses in sediments (suspended, riverbed, and downcore) of the Xingu and Tapajós rias to investigate the effects of hydrologic variations on the carbon budget in these clearwater rivers over the Holocene. Ages of sediment deposition (~100 to 5,500 years) were constrained by optically stimulated luminescence and radiocarbon. Major elements geochemistry and concentration of total organic carbon (TOC) indicate that seasonal hydrologic variations exert a strong influence on riverine productivity and on the input and preservation of organic matter in sediments. Stable carbon isotope data (δ13C from −31.04 to −27.49‰) and pollen analysis indicate that most of the carbon buried in rias is derived from forests. In the Xingu River, diatom analysis in bottom sediments revealed 65 infrageneric taxa that are mostly well-adapted to slack oligotrophic and acidic waters. TOC values in sediment cores are similar to values measured in riverbed sediments and indicate suitable conditions for organic matter preservation in sediments of the Xingu and Tapajós rias at least since the mid-Holocene, with carbon burial rates varying from about 84 g m−2 yr−1 to 169 g m−2 yr−1. However, redox-sensitive elements in sediment core indicate alternation between anoxic/dysoxic and oxic conditions in the water-sediment interface that may be linked to abrupt changes in precipitation. The variation between anoxic/dysoxic and oxic conditions in the water-sediment interface controls organic matter mineralization and methanogenesis. Thus, such changes promoted by hydrological variations significantly affect the capacity of Amazon rias to act either as sources or sinks of carbon

    Doença de Marek visceral em pavão-branco (Pavo cristatus)

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    Doença de Marek (MD) é uma desordem linfoproliferativa causada pelo Gallid herpesvirus 2 (MDV), que infecta principalmente galináceos domésticos, porém aves silvestres podem ser ocasionalmente afetadas. O presente relato descreve os achados anatomopatológicos e moleculares de um caso de MD em um pavão-branco (Pavo cristatus). Os sinais clínicos incluíram apatia, hiporexia e diarreia. Macroscopicamente, foram observados nódulos macios, de 0,5 a 1,5cm de diâmetro, no músculo esquelético, no pulmão, nos rins, nos sacos aéreos, no intestino delgado, no coração, no ovário, no ventrículo e no proventrículo. Microscopicamente, numerosas células redondas neoplásicas atípicas foram notadas. A detecção molecular do DNA do MDV foi implementada para amplificar parte do gene meq, e os produtos foram sequenciados para análise filogenética. DNA foi obtido de tecidos de aves afetadas e do sangue de todos os galináceos do zoológico. A esperada amplificação de parte do gene meq de MDV amplificado foi ampliada e sequenciada. As sequências obtidas permitiram o agrupamento da cepa (acesso KT768121) com cepas do sorotipo 1 de MDV do GenBank.. O diagnóstico de MD em pavão-branco foi obtido com base nos achados anatomopatológicos e moleculares e, pelo conhecimento dos autores, não há relatos anteriores publicados de MD em Pavo cristatus.Marek's disease (MD) is a lymphoproliferative disorder caused by Gallid herpesvirus 2 (MDV) that infects mainly domestic gallinaceous birds although wild birds may occasionally be affected. The current report describes the anatomopathological and molecular findings of a case of MD in a white-peafowl (Pavo cristatus). The signs included apathy, hyporexia, and diarrhea. Grossly, 0.5 to 1.5cm in diameter, yellow, soft nodules were observed in the skeletal muscle, lung, kidney, air sacs, small intestine, heart, ovary, ventriculus, and proventriculus. Microscopically, numerous atypical round neoplastic cells were noted. The molecular detection of MDV DNA was implemented to amplify part of the meq gene and products were sequenced for the phylogenetic analysis. Template DNA was obtained from tissues of the affected bird and from blood of all the gallinaceous birds of the Zoo. The expected amplicon for the partial amplification of MDV meq gene was obtained and the amplicons were sequenced. Sequences obtained enabled grouping the strain (accession no. KT768121) with MDV serotype 1 strains from the GenBank. Based on the anatomopathological and molecular findings, the diagnosis of MD in a white-peafowl was reached, and to the authors' knowledge, no previous report regarding MD was published in Pavo cristatus

    Environmental and sanitary conditions of guanabara bay, Rio de Janeiro

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    Guanabara Bay is the second largest bay in the coast of Brazil, with an area of 384 km2. In its surroundings live circa 16 million inhabitants, out of which 6 million live in Rio de Janeiro city, one of the largest cities of the country, and the host of the 2016 Olympic Games. Anthropogenic interference in Guanabara Bay area started early in the XVI century, but environmental impacts escalated from 1930, when this region underwent an industrialization process. Herein we present an overview of the current environmental and sanitary conditions of Guanabara Bay, a consequence of all these decades of impacts. We will focus on microbial communities, how they may affect higher trophic levels of the aquatic community and also human health. The anthropogenic impacts in the bay are flagged by heavy eutrophication and by the emergence of pathogenic microorganisms that are either carried by domestic and/or hospital waste (e.g., virus, KPC-producing bacteria, and fecal coliforms), or that proliferate in such conditions (e.g., vibrios). Antibiotic resistance genes are commonly found in metagenomes of Guanabara Bay planktonic microorganisms. Furthermore, eutrophication results in recurrent algal blooms, with signs of a shift toward flagellated, mixotrophic groups, including several potentially harmful species. A recent large-scale fish kill episode, and a long trend decrease in fish stocks also reflects the bay’s degraded water quality. Although pollution of Guanabara Bay is not a recent problem, the hosting of the 2016 Olympic Games propelled the government to launch a series of plans to restore the bay’s water quality. If all plans are fully implemented, the restoration of Guanabara Bay and its shores may be one of the best legacies of the Olympic Games in Rio de Janeiro
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