Effect of age on the viability of pig intestinal explants: a histological and ultrastructural approach

Intestinal explants are a useful model for toxicological and pathological studies, but the maintenance of tissue viability for longer periods of incubation remains challenging. The aim of this study was to evaluate the effect of age on the viability of intestinal explants. Jejunal explants were obtained from 24- and 42-day-old piglets. The explants were incubated for two or four hours and were then processed for histological analysis. The explants from younger pigs showed minor histological changes, as assessed by histological and morphometrical scores. Explants from 24-day-old pigs were incubated for four hours and subjected to ultrastructural analysis to assess cell integrity. The plasma membranes, nuclei and organelles of enterocytes were well preserved, and adsorptive endocytosis was observed. In conclusion, the data indicate that the age of the donor influences explant viability. The intestinal morphology of incubated explants from young donors was better preserved than that of explants from older piglets

Alocação dos custos de melhorias em bacias hidrográficas entre os usuários de água: uma aplicação do valor de Shapley

The objective of this work was to analyze the cost allocation of improvements in river basins among the water users. It was used, as example, the Paraíba do Sul river basin, located in the states of Minas Gerais, São Paulo and Rio de Janeiro, and, as criteria of allocation of costs, they were used the volumes of water extracted and consumed, and the quantity of pollutants deposited in the basin area by water users. The methodology used consists of the rule of allocation known as Shapley value, which belongs to the cooperative branch of game theory. In the case of Paraíba do Sul river basin, the values found indicated that the urban users should pay the higher part of the costs of improvements, given that these users are responsible for most of the pollution in the basin area, being the reduction of water quality an important problem in this basin.water resources, cost allocation, Shapley value, Paraíba do Sul river basin, Environmental Economics and Policy,

Alocação dos custos de melhorias em bacias hidrográficas entre os usuários de água: uma aplicação do valor de Shapley

The objective of this work was to analyze the cost allocation of improvements in river basins among the water users. It was used, as example, the Paraíba do Sul river basin, located in the states of Minas Gerais, São Paulo and Rio de Janeiro, and, as criteria of allocation of costs, they were used the volumes of water extracted and consumed, and the quantity of pollutants deposited in the basin area by water users. The methodology used consists of the rule of allocation known as Shapley value, which belongs to the cooperative branch of game theory. In the case of Paraíba do Sul river basin, the values found indicated that the urban users should pay the higher part of the costs of improvements, given that these users are responsible for most of the pollution in the basin area, being the reduction of water quality an important problem in this basin.Water resources, cost allocation, shapley value, Paraíba do Sul River basin, Environmental Economics and Policy,

Metodologia de avaliação de projetos de saneamento

The Sanitation Law (Law 11.445/2007), a milestone in the way to improve the sanitary conditions in Brazil, establishes as a fundamental item the economic sustainability of water and wastewater services. Therefore, the design and modus operandi of these systems is a key issue and the assessment methods are important tools to support the decision-making process. The objective of this study was to propose a methodology for assessment of water and wastewater projects in Brazil. To that purpose, it was made a documentary analysis of the main references on the subject in Europe, US and Brazil as well as the World Bank, reference institution in leading project evaluations. Then, it was analyzed the specific issues of water and wastewater in Brazil, considering the premises and necessary information for carry out projects evaluation in the Brazilian context. As a result of this work, it was produced a manual and an electronic evaluation model for water and wastewater projects. The manual presents clearly and concisely the steps to be taken in the evaluation of projects and the electronic model allow working the quantitative aspects of the project under study. The model was tested in a case study and has proved its efficiency since it was able to provide enough information to support the decision-making process. The information produced allows the investor to allocate its resources in the most efficient way and choose between different alternatives that one which provides the best results. For the situation presented in the case study, implementation of wastewater system in the municipality of Miracema do Tocantins, the analysis made clear the financial infeasibility of the project, although economically viable, and the need to seek other project feasibility mechanisms.A Lei nº 11.445/2007 (BRASIL, 2010), conhecida como Marco do Saneamento no Brasil, prevê como item fundamental a eficiência e sustentabilidade econômica dos serviços de saneamento. Assim, o estudo prévio do arranjo e modus operandi do sistema de saneamento é uma questão fundamental e os métodos de avaliação se mostram como uma ferramenta importante de auxílio no processo de tomada de decisão. Dessa forma, o objetivo deste trabalho foi propor uma metodologia de avaliação de projetos de água e esgoto no Brasil. Para tanto, foi feita uma análise documental das principais referências no assunto na Europa, Estados Unidos e Brasil bem como do Banco Mundial, instituição de referência na condução de avaliações de projetos. Em seguida, estudaram-se as especificidades do saneamento no Brasil, considerando as premissas e informações necessárias para realização da avaliação no contexto brasileiro. Como resultado deste trabalho, foi produzido um manual e um modelo eletrônico de avaliação de projetos de saneamento. O manual apresenta de forma clara e sucinta as etapas a serem percorridas na avaliação de projetos e o modelo permite trabalhar os aspectos quantitativos do projeto em estudo. O modelo foi testado em um estudo de caso que permitiu comprovar a sua eficiência visto que foi capaz de fornecer os principais dados que devem subsidiar a tomada de decisão quanto à realização dos investimentos. As informações produzidas permitem ao investidor que ele aloque seus recursos da forma mais eficiente e escolha entre diversas alternativas aquela que ofereça o melhor resultado. Para o caso específico do projeto estudado, implantação do sistema de esgotamento sanitário no Município de Miracema do Tocantins, a análise deixou clara a inviabilidade financeira do projeto, ainda que economicamente viável, e a necessidade de buscar outros mecanismos de viabilização do projeto

The food contaminant deoxynivalenol, decreases intestinal barrier permeability and reduces claudin expression

The gastrointestinal tract represents the first barrier against food contaminants as well as the first target for these toxicants. Deoxynivalenol (DON) is a mycotoxin that commonly contaminates cereals and causes various toxicological effects. Through consumption of contaminated cereals and cereal products, human and pigs are exposed to this mycotoxin. Using in vitro, ex vivo, and in vivo approaches, we investigated the effects of DON on the intestinal epithelium. We demonstrated that, in intestinal epithelial cell lines from porcine (IPEC-1) or human (Caco-2) origin, DON decreases trans-epithelial electric resistance (TEER) and increases in a time and dose-dependent manner the paracellular permeability to 4 kDa dextran and to pathogenic Escherichia Coli across intestinal cell monolayers. In pig explants treated with DON, we also observed an increased permeability of intestinal tissue. These alterations of barrier function were associated with a specific reduction in the expression of claudins, which was also seen in vivo in the jejunum of piglets exposed to DON-contaminated feed. In conclusion, DON alters claudin expression and decreases the barrier function of the intestinal epithelium. Considering that high levels of DON may be present in food or feed, consumption of DON-contaminated food/feed may induce intestinal damage and has consequences for human and animal health

Clinical and Pathological Features of Canine Metastatic Adrenocortical Carcinoma

 Background: Adrenocortical carcinomas (ACC) are uncommon in dogs. ACC often invade the posterior vena cava wall and the advential layer of the abdominal aorta; however, metastases to distant organs are rare. Most dogs with ACC show clinical signs of Cushing`s syndrome in a similar way with signs reported in humans. The aim of this study is to report three cases of metastatic ACC in dogs and their clinical and pathological features.Cases: This report describes three cases of metastatic adrenocortical carcinoma (ACC) in dogs diagnosed post mortem through histopathological examination. The animals presented no signs of adrenal hormones overproduction. Case 1. A 13-year-old intact, mixed breed female dog was presented with a history of progressive hepatomegaly during the last four months. The animal was submitted to an exploratory laparotomy, but due to anesthetic complications no tissue specimen was sampled and after one week, the animal died. The necropsy examination showed an increased left adrenal (3 cm in diameter), multiple yellow to whitish nodules measuring 1 to 2 cm of diameter in the lung and severe hepatomegaly. The histopathological diagnosis was established as ACC with pulmonary metastasis. A severe and diffuse accumulation of gly­cogen in hepatocytes was also observed in Periodic acid-Schiff (PAS) staining. Case 2. A 9-year-old female intact, mixed breed dog was presented showing ataxia, left head-tilt and dyspnoea. The clinical signs progressed and the dog died after four days. The gross examination showed a diffuse increase of the left adrenal gland (2 cm of diameter) accompanied by a yellowish colour at cut surface; diffuse bronchopneumonia and cerebral and renal discrete congestion. The microscopi­cal diagnosis was ACC with kidney and CNS metastasis. Case 3. A 16-year-old male, intact, Poodle dog was presented with apathy, anorexia, vomiting and diarrhoea in the last two days. The animal was submitted to treatment, but the clinical signs progressed and the dog died. In the necropsy exam an increased right adrenal gland was observed (5 cm of diameter) showing multiple yellowish nodules when sectioned. The lung showed multiple whitish nodules mainly in pleural region. In the histopathological examination, the definitive diagnosis was ACC with pulmonary metastasis.Discussion: Most of adrenocortical tumours in dogs are functional and secrete excessive amounts of cortisol; therefore commonly animals show clinical signs of Cushing`s syndrome. In the present cases, the animals showed no clinical evidence of hormonal changes. Well-differentiated neoplastic cells were observed in cases 1 and 2, whereas in case 3 tumorous cells showed marked features of malignancy as cellular pleomorphism, binucleation, high mitotic index and atypical mitosis. Despite mild anaplastic features observed on cases 1 and 2, animals showed focus of metastases in lung, kidney and CNS. Apparently features of malignancy in ACC were not associated to the risk of metastasis development, indicating that even well-differentiated ACC may metastasize to distant organs. Metastases of ACC to distant sites are rare in dogs and there was no previous report of metastasis to CNS as observed in case 2. Canine ACC are considered uncommon tumours, how­ever, they should be included in the differential diagnosis of mass in the abdominal cavity since the animals may show no clinical signs of adrenocortical hormones overproduction.Keywords: adrenal tumours, adrenocortical hormones, metastases, dog