Histopathological, immunohistochemical and ultraestructural evaluation of inflammatory response in Arius genus fish under experimental inoculation of BCG

The aim of this study was to evaluate the inflammatory response kinetics after experimental inoculation with BCG in the primitive Arius sp. fish. The BCG was applied through the intramuscular injection in the caudal peduncular region, and the samples were collected for the analyses at days 1, 3, 7, 14, 21, and 33 post-injection. Acute phase inflammatory infiltrate was characterized by the predominant mononuclear cells, intersticial edema, and muscular tissue necrosis. As the inflammatory response evolved, a large number of multinuclear giant cells were formed containing the BCG. These giant cells were positive for the S100 protein at the histochemical analysis, which demonstrate the macrofage activity, confirmed by the ultra-structural analysis showing the lack of the cytoplasmic membrane enveloping the many nuclei within the giant cell. These results led to the conclusion that Arius sp. fish injected with the BCG showed a difuse inflammatory response characterized by a large number of mononuclear cells, absence of granuloma formation, and predominant giant cells.

Remyelination in experimentally demyelinated connexin 32 KnockOut mice

The aim of this study was to evaluate the role of connexin 32 (Cx 32) during remyelination of the peripheral nervous system, through a local injection of either 0,1% ethidium bromide solution or saline in the sciatic nerve of Cx 32 knockout mice. Euthanasia was performed ranging from 1, 2, 3, 7, 15, 21 to 30 days after injection. Histochemical, immunohistochemical, immunofluorescence and transmission electron microscopical techniques were used to analyze the development of the lesions. Within the sciatic nerves, Schwann cells initially showed signs of intoxication and rejected their sheaths; after seven days, some thin newly formed myelin sheaths with uneven compactness and redundant loops (tomacula) were conspicuous. We concluded that the regeneration of lost myelin sheaths within the PNS followed the pattern already reported for this model in other laboratory species. Therefore, these results suggest that absence of Cx 32 did not interfere with the normal pattern of remyelination in this model in young mice.

Evaluation of the efficacy of hydrated sodium aluminosilicate in the prevention of aflatoxin-induced hepatic cancer in rainbow trout

The use of aluminum silicates for decontaminating animal feed containing aflatoxins has yielded encouraging results in chicken and turkey poults. In contrast, very few studies have tested these substances in aquaculture. In this work, we investigated the efficacy of a trout diet containing 0.5% hydrated sodium aluminosilicate (HSAS) in protecting against contamination with aflatoxin B1. Trout were reared on these diets for one year and the experimental groups were examined monthly for hepatic presumptive preneoplastic and neoplastic lesions. Regardless of the presence of HSAS, all of the fish that received aflatoxin in their diet have shown hepatic lesions indicative of a carcinogenic process, presenting also the development of cancer in some fish. The concentration of HSAS used in this study was ineffective in preventing the onset of hepatic lesions induced by aflatoxin B1 in rainbow trout.

Utilização de pelos de animais silvestres para monitoramento ambiental de Cd, Cr, Cu, Fe, Mn, Pb e Zn

This study investigates the use of wild animal hair of C. brachyurus, C. thous and L. pardalis as biomonitors of trace metal at Parque Nacional das Emas, Brazil. Results reveal a strong correlation between Cd and Pb as well as Cu and Zn, which suggests a single source of emission. Most metals showed a lower or equal concentration than those obtained in previous studies. The research shows that monitoring may be performed only with Zn, Pb, Cd, and Cr because of statistical similarity and of a non-natural occurrence of large amounts of the material under analysis.

Cobertura de linhas telefônicas residenciais e vícios potenciais em estudos epidemiológicos

OBJETIVO: Estimar o efeito da taxa de cobertura de linhas telefônicas residenciais em potenciais vícios de informação em inquéritos epidemiológicos. MÉTODOS: Foram utilizadas as bases de dados da Pesquisa Nacional por Amostra de Domicílios no período de 1998 a 2003 para a estimativa das taxas de cobertura de linhas telefônicas residenciais nas cinco regiões geográficas brasileiras. Utilizou-se a regressão logística múltipla para identificar os fatores associados à posse de linha telefônica fixa. O impacto do vício nos intervalos com 95% de confiança foi avaliado em função da precisão alcançada em cada situação. RESULTADOS: Nas regiões metropolitanas Sudeste, Sul e Centro-Oeste com 70% e mais de cobertura, os vícios associados foram considerados desprezíveis. Nas demais regiões, os vícios relativos estavam acima do limite aceitável (0,4), indicando possíveis erros nas inferências construídas sob intervalo com 95% de confiança. A chance de acesso à linha telefônica residencial foi maior para população com cor da pele branca e maior escolaridade. CONCLUSÕES: Os achados mostram que o uso de cadastro de linhas telefônicas residenciais é indicado para a realização de inquéritos epidemiológicos apenas para estados com cobertura acima de 70%. Metodologias específicas para o tratamento de estimativas obtidas em localidades com taxas inferiores, precisam ser estudadas e divulgadas

Arterial supply of the penis in agoutis (Dasyprocta prymnolpha, Wagler, 1831)

The arterial vascularization of agoutis` penis (Dasyprocta prymnolopha) were analysed using ten male adults from `Nucleo de Estudos e Preservacao de Animais Silvestres da Universidade Federal do Piaui` (FUFPI/IBAMA n degrees 02/99). Among the total number of specimens, six animals had natural death and were members of the research collection of the Laboratory of Anatomy, and four were killed after anaesthesia. Stained bi-centrifugated-Cis-I-4 latex was injected in arterial vessels responsible for penis vascularization throughout the abdominal portion of aorta. The samples were fixed in 10% formaldehyde solution and arteries were dissected. The penile artery is originated as a branch of internal pudendal artery. At the level of ischiatic arch, the penile artery project two branches, the penile dorsal and the deep arteries; those arteries irrigates the penile dorsal surface and the corpus cavernosum penis. The penile dorsal arteries have an independent course up to the glans penis. Based on the conditions of this work a remarkable similarity regarding the distribution of vessels destined to the agouti penis when compared to other domestic, wild and lagomorph rodents as rabbits.