Sequential morphological characteristics of murine fetal liver hematopoietic microenvironment in Swiss Webster mice

Embryonic hematopoiesis occurs via dynamic development with cells migrating into various organs. Fetal liver is the main hematopoietic organ responsible for hematopoietic cell expansion during embryologic development. We describe the morphological sequential characteristics of murine fetal liver niches that favor the settlement and migration of hematopoietic cells from 12 days post-coitum (dpc) to 0 day post-partum. Liver sections were stained with hematoxylin and eosin, Lennert’s Giemsa, Sirius Red pH 10.2, Gomori’s Reticulin, and Periodic Acid Schiff/Alcian Blue pH 1.0 and pH 2.5 and were analyzed by bright-field microscopy. Indirect imunohistochemistry for fibronectin, matrix metalloproteinase-1 (MMP-1), and MMP-9 and histochemistry for naphthol AS-D chloroacetate esterase (NCAE) were analyzed by confocal microscopy. The results showed that fibronectin was related to the promotion of hepatocyte and trabecular differentiation; reticular fibers did not appear to participate in fetal hematopoiesis but contributed to the physical support of the liver after 18 dpc. During the immature phase, hepatocytes acted as the fundamental stroma for the erythroid lineage. The appearance of myeloid cells in the liver was related to perivascular and subcapsular collagen, and NCAE preceded MMP-1 expression in neutrophils, an occurrence that appeared to contribute to their liver evasion. Thus, the murine fetal liver during ontogenesis shows two different phases: one immature and mainly endodermic (<14 dpc) and the other more developed (endodermic-mesenchymal; >15 dpc) with the maturation of hepatocytes, a better definition of trabecular pattern, and an increase in the connective tissue in the capsule, portal spaces, and liver parenchyma. The decrease of hepatic hematopoiesis (migration) coincides with hepatic maturation

Chagas' disease: an algorithm for donor screening and positive donor counseling

Classical serological screening assays for Chagas' disease are time consuming and subjective. The objective of the present work is to evaluate the enzyme immuno-assay (ELISA) methodology and to propose an algorithm for blood banks to be applied to Chagas' disease. Seven thousand, nine hundred and ninety nine blood donor samples were screened by both reverse passive hemagglutination (RPHA) and indirect immunofluorescence assay (IFA). Samples reactive on RPHA and/or IFA were submitted to supplementary RPHA, IFA and complement fixation (CFA) tests. This strategy allowed us to create a panel of 60 samples to evaluate the ELISA methodology from 3 different manufacturers. The sensitivity of the screening by IFA and the 3 different ELISA's was 100%. The specificity was better on ELISA methodology. For Chagas disease, ELISA seems to be the best test for blood donor screening, because it showed high sensitivity and specificity, it is not subjective and can be automated. Therefore, it was possible to propose an algorithm to screen samples and confirm donor results at the blood bank.<br>Os testes sorológicos clássicos utilizados na triagem de doadores de sangue são trabalhosos e subjetivos. O objetivo do presente trabalho é o de avaliar a metodologia imuno-enzimática (ELISA) e propor um algorítmo para doença de Chagas em bancos de sangue. Foram estudados 7999 doadores de sangue e/ou componentes cujas amostras foram testadas com o objetivo de tria-las sorologicamente para doença de Chagas utilizando hemaglutinação passiva reversa (RPHA) e imunofluorescência indireta (IFA). As amostras reativas em pelo menos uma destas metodologias, foram retestadas com reativos diferentes por RPHA, IFA e fixação de complemento (CFA). Esta estratégia nos permitiu criar um painel de 60 amostras com as quais tornou-se possível a avaliação do método imunoenzimático (ELISA). A sensibilidade da triagem dos doadores pelos métodos ELISA e IFA foi de 100%. A especificidade foi melhor para a metodologia imunoenzimática. O teste ELISA parece ser o ideal para triagem em bancos de sangue pois é altamente sensível, específico, não é subjetivo e pode ser automatizado. Desta forma, torna-se possível a formulação de um algorítimo a ser utilizado na triagem sorológica e confirmação de resultados em doadores de bancos de sangue

Natural Schistosoma mansoni infection in Nectomys squamipes: histopathological and morphometric analysis in comparison to experimentally infected N. squamipes and C3H/He mice

Histopathologic and morphometric (area, perimeter, major and minor diameters) analysis of hepatic granulomas isolated from twelve naturally infected Nectomys squamipes were compared to four experimentally infected ones and six C3H/He mice. Liver paraffin sections were stained for cells and extracellular matrix. Both groups of N. squamipes presented peculiar granulomas consisting predominantly of large macrophages, full of schistosome pigment, characterizing an exudative-macrophage granuloma type, smaller than the equivalent granuloma type in mouse. Naturally infected animals exhibited granulomas in different stages of development, including large number of involutional types. Morphometric analysis showed that all measurements were smaller in naturally infected animals than in other groups. The results demonstrated that both N. squamipes groups reproduced, with small variations, the hepatic granuloma aspects already described in cricetidium (Calomys callosus), showing a genetic tendency to set up strong macrophage responses and small granulomas. Unexpectedly, natural infection did not engender distinguished histopathological characteristics distinct from those derived from experimental single infection, showing changes predominantly secondary to the duration of infection. It appears that the variability of the inocula (and the number of infections?) interfere more with the quantity than with the quality of the pathological changes, denoting some morpho-functional determinism in the response to schistosomal infection dependent on the animal species

Avaliação da qualidade nutricional da silagem de cana-de-açúcar com aditivos microbianos e enriquecida com resíduo da colheita de soja Evaluation of the nutritional quality of sugarcane silage treated with microbial additives and soybean crop residue

Objetivou-se avaliar as características fermentativas e a qualidade nutricional da silagem de cana-de-açúcar tratada com aditivos microbianos e enriquecida com 10% de resíduo da colheita de soja, com base no peso verde da cana. O experimento foi conduzido em delineamento inteiramente ao acaso, com três repetições, utilizando-se a variedade RB855536, colhida em soca aos 16 meses. Embora a adição do resíduo da colheita de soja tenha promovido aumento do pH final da silagem, os tratamentos com resíduo diminuíram em 33% as perdas de matéria seca das silagens e em 60% o teor de N-amoniacal em relação ao nitrogênio total. A adição dos inoculantes reduziu o pH da silagem quando em associação ao resíduo de soja, não exercendo efeito significativo sobre os outros parâmetros estudados. Em todos os tratamentos, as silagens apresentaram maiores concentrações dos componentes da fibra e redução nos teores de MS em relação ao material original, antes da ensilagem. Nos tratamentos com resíduo, os valores de digestibilidade in vitro da matéria seca (DIVMS) foram superiores aos obtidos nos demais tratamentos. Quando comparado o material utilizado para ensilagem, a redução na digestibilidade foi superior para os tratamentos sem o resíduo (24,3 vs 9,3%). A associação do resíduo da colheita de soja à cana-de-açúcar para ensilagem proporcionou melhor qualidade nutritiva, com menores perdas de MS e carboidratos solúveis, principalmente na forma de gases, e, conseqüentemente, menor acúmulo dos componentes da parede celular, além de redução na DIVMS da forragem. Não se recomenda a utilização dos inoculantes L. plantarum e L. buchneri na ensilagem da cana-de-açúcar, pois nenhuma melhoria foi observada na composição química ou no perfil de fermentação das silagens.<br>The objective of this trial was to evaluate the fermentative characteristics and nutritional quality of sugarcane treated with microbial additives and 10% of soybean crop residue based on sugarcane fresh weight. The variety RB855536 harvested at 16 months of age was used in a completely randomized design with tree repetitions. Addition of soybean crop residue reduced 33% of DM losses and 60% of ammonia-N (% total N) although final silage pH increased. Use of inoculants reduced silage pH only in association with soybean crop residue with no significant effects on the remaining variables. For all treatments, silages had higher contents of fiber and lower DM levels than the material before ensiling. In vitro dry matter digestibility (IVDMD) was significantly higher (P<0.05) on treatments with soybean crop residue compared to the other treatments. Moreover, compared with the material used for ensiling, reduction in digestibility was higher for treatments without soybean crop residue (24.3% vs. 9.3%). Combination of soybean crop residue with sugarcane improved nutritional quality and reduced DM and soluble carbohydrates losses, mainly in the form of gases, diluting the proportion of cell wall components and preventing losses in forage IVDMD. The use of the inoculants L. plantarum and L. buchneri during ensiling of sugarcane is not recommended because no improvement was observed on the chemical composition or fermentation profile of silages