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Introdução: O papel da metaplasia intestinal (MI) como lesão pré-cancerosa gástrica não está completamente esclarecido. Objetivos: Analisar a distribuição e o tipo de MI em relação aos tipos de carcinoma gástrico (CG). Material e Método: Analisaram-se 71 peças de gastrectomia por CG. Amostras da neoplasia e da mucosa a intervalos regulares de toda a peça foram processadas rotineiramente; os cortes histológicos foram corados por HE e histoquímica para mucinas. A gastrite crônica atrófica (GCA) e a MI foram analisadas quanto a topografia, intensidade e tipo e correlacionadas com o subtipo da neoplasia. Resultados: Diagnosticaram-se 42 (59%) CGs do tipo intestinal (CaI), 17 (24%) difusos (CaD) e 12 (17%) não foram classificáveis. A GCA e a MI foram mais intensas no CaI do que no CaD (p = 0,02; p = 0,004). Observaram-se focos de MI dos tipos I, II e III em 21 CaI (50%), enquanto que 5/17 (29%) CaD com MI apresentavam focos de MI de tipos I e II. A MI do tipo III foi diagnosticada em 21 CaI (50%) e em seis CaD (35%) (p = 0,04); nas áreas peritumorais com MI, a do tipo III foi detectada em 13/34 (38%) CaI e 3/10 (30%) CaD. Houve correlação entre a intensidade da MI e o tipo da lesão (p = 0,005), observando-se MI de tipo III predominantemente quando as lesões eram de intensidade moderada a acentuada. Conclusões: A MI de tipo III pode ser considerada um marcador da intensidade do processo metaplásico. Sua presença em 50% dos CaI limita seu papel como lesão de risco e reforça a hipótese da existência de diversas vias carcinogênicas para o CG.

Biosurfactants are surfactants biologically produced by microorganisms, presenting several advantages when compared to synthetic surfactants. Pseudomonas aeruginosa is known for producing rhamnolipids, considered one of the most interesting types of biosurfactants due to their high yields, when compared to other types. In this work, the production of rhamnolipid from P. aeruginosa was optimized. At first, the Plackett–Burman design was used to select most significant variables affecting the biosurfactant production yield among nine variables—carbon–nitrogen ratio, carbon concentration, nitrogen source, pH, cultivation time, potassium and magnesium concentrations, agitation, and temperature. Then, using main variables, a central point experimental design aiming to optimize rhamnolipid production was performed. The maximum biosurfactant concentration obtained was 0.877 mg L−1. The rhamnolipid also displayed a great emulsification rate, reaching approximately 67%, and the ability to reduce water surface tension from 72.02 to 35.26 mN m−1 at a critical micelle concentration (CMC) of 127 mg L−1, in addition to presenting a good stability when exposed to wide pH and salinity ranges. The results suggest that rhamnolipids are promising substitutes for synthetic surfactants, especially due to lower impacts on the environment. [ABSTRACT FROM AUTHOR]

Previously, mucus of some molluscs has been studied as a potential source of new natural compounds capable of inducing cell proliferation and of remodelling tissue. Here, the focus of the study is possible use of mucus released by Phyllocaulis boraceiensis - a compound inducing cell proliferation and enhancing collagen synthesis in dermal fibroblasts and inducing proliferation human endothelial cell cultures. Fibroblasts treated with P. boraceiensis mucus at concentrations below 0.012 μg/μl developed high rates of proliferation, as evaluated using MTT assay; the proliferative effect was dose-dependent. Production and secretion of extracellular matrix components and collagen type I fibres were enhanced after 24 h of treatment, revealing a hormesis effect, biphasic dose response - low dose for proliferation yet toxic at high dose. No significant change in proliferation was observed in treated endothelial cells and production of lipid polyunsaturated free radicals was low in both cell types. Treatment with P. boraceiensis mucus produced pronounced changes in fibroblast cell number and morphology, and in quantities of well-ordered collagen deposition. These results support the premise that Phyllocaulis boraceiensis mucus demonstrates proliferative properties in cells involved in the healing process. [ABSTRACT FROM AUTHOR]

Examines the role of circumscribed lesion of the medial forebrain bundle area in causing structural impairment of lympoid organs and severe depression of immune function in rats. Mechanisms involved in the regulation of immune function; Effect of food deprivation or changes in corticosteroid levels in causing changes in the function of lymphoid organs.

Abstract: The placenta of mammals is a structure formed by the juxtaposition of the fetal membranes and the maternal tissues. The main function of the placenta is to regulate the physiological interchange between the fetus and the mother as well as to operate as an important endocrine organ during the gestation. The placentomal fusions were characterized throughout gestation of cattle using macroscopic, histological and flow cytometry analyses. Analyzing the cell cycle phases with a flow cytometry, a balance between the G2M phase and apoptosis was observed, suggesting that the placentomal fusions do not interfere in the placentary maturation process, which is a pre-requirement for the fetal-maternal disconnection and the release of fetal membrane. [Copyright &y& Elsevier]

Abstract: The bovine maternal epithelium is composed of cuboidal cells interspersed with low columnar cells having centrally located nuclei. Bovine trophoblast is composed of two cell types: mononuclear trophoblastic and giant trophoblastic cells that can have two or more nuclei. Number of apoptotic cells and proliferative cells are variable in both cell populations. This study compared tissue growth and apoptosis by flow cytometry in the cell population found at distinct placental regions (central region of placentomes, ≤1-cm microplacentomes and the interplacentomal region) between normal and cloned near-term bovine pregnancies. After a morphological comparison between regions and groups (controls vs. clones), a lesser proportion of diploid to tetraploid cells was observed in the central region of placentomes and in microplacentomes from cloned-derived pregnancies. In addition, cloned animals had a fewer apoptotic cells in the central region of the placentome and in interplacentomal region and a greater proliferative capacity in all regions (cells in G2/M) near term as opposed to control animals. These results may reveal the existence of a relationship between such changes in the proportions of uterine and trophoblastic epithelial cells at the end of pregnancy and normal placental function. This could be related to faulty placentation in early pregnancy, placental insufficiency during pregnancy or lack of placental and/or fetal maturation in late pregnancy, which may contribute to some of the abnormalities after in vitro embryo manipulations, such as poor preparation and initiation of parturition, prolonged gestation and lesser post-natal survival in some cloned animals. [Copyright &y& Elsevier]