Induction by transforming growth factor-β1 of epithelial to mesenchymal transition is a rare event in vitro

INTRODUCTION: Transforming growth factor (TGF)-β1 is proposed to inhibit the growth of epithelial cells in early tumorigenesis, and to promote tumor cell motility and invasion in the later stages of carcinogenesis through the induction of an epithelial to mesenchymal transition (EMT). EMT is a multistep process that is characterized by changes in cell morphology and dissociation of cell–cell contacts. Although there is growing interest in TGF-β1-mediated EMT, the phenotype is limited to only a few murine cell lines and mouse models. METHODS: To identify alternative cell systems in which to study TGF-β1-induced EMT, 18 human and mouse established cell lines and cultures of two human primary epithelial cell types were screened for TGF-β1-induced EMT by analysis of cell morphology, and localization of zonula occludens-1, E-cadherin, and F-actin. Sensitivity to TGF-β1 was also determined by [(3)H]thymidine incorporation, flow cytometry, phosphorylation of Smad2, and total levels of Smad2 and Smad3 in these cell lines and in six additional cancer cell lines. RESULTS: TGF-β1 inhibited the growth of most nontransformed cells screened, but many of the cancer cell lines were insensitive to the growth inhibitory effects of TGF-β1. In contrast, TGF-β1 induced Smad2 phosphorylation in the majority of cell lines, including cell lines resistant to TGF-β1-mediated cell cycle arrest. Of the cell lines screened only two underwent TGF-β1-induced EMT. CONCLUSION: The results presented herein show that, although many cancer cell lines have lost sensitivity to the growth inhibitory effect of TGF-β1, most show evidence of TGF-β1 signal transduction, but only a few cell lines undergo TGF-β1-mediated EMT

Efeito da forma física da ração sobre a porosidade, espessura da casca, perda de água e eclodibilidade em ovos de perdiz (Rhynchotus rufescens) Effect of the physical form of diet on the eggshell porosity and thickness, water loss and hatchability of partridge (Rhynchotus rufescens) eggs

O objetivo do presente estudo foi avaliar se a forma física da ração (farelada e peletizada) afeta a porosidade e espessura da casca, e porcentagem de perda de água e eclodibilidade de ovos de perdiz. Os ovos foram coletados logo após a postura e separados em diferentes intervalos de peso (35-45g, 46-50g, 51-55g, 56-60g e 61-70g), sendo 10 ovos/classe/ração. O número de poros das cascas foi avaliado nas regiões apical, equatorial e basal dos ovos. Utilizou-se um micrômetro digital para a mensuração da espessura das três regiões da casca dos ovos, a partir dos quais obteve-se a espessura média por ovo. Os ovos para avaliação da eclodibilidade e porcentagem de perda de água do ovo até a transferência para o nascedouro (16º dia) foram pesados, desinfectados, incubados (T=35,5&ordm;C e UR= 70%) e transferidos no 16&ordm; dia de incubação para o nascedouro, onde foram mantidos até a eclosão. As análises estatísticas empregadas foram: Análise de Variância e de Correlação, e teste de Tukey 5%. Os dados mostraram que, em perdizes, o número de poros na casca pode variar com a região da casca, peso do ovo e a forma física da ração, e que a ingestão de ração peletizada promove um aumento na espessura da casca dos ovos sem alterar a eclodibilidade e a porcentagem de perda de água dos mesmos durante a incubação.<br>The aim of this study was to determine the effect of the ingestion of meal and pelleted diets on eggshell porosity and thickness, water loss and hatchability percentages of partridge (Rhynchotus rufescens) eggs. The eggs (n=100) were divided into five different weight classes (1: 35-45 g, 2: 46-50 g, 3: 51-55 g, 4: 56-60 g, 5: 61-70 g). Parts from different regions (air space, equator and small end) of each eggshell were analized in order to count pore numbers. Eggshell thickness measurements were carried out after removal of the egg membranes. The eggs used in the analyses of the water loss and hatchability percentages were weighed, desinfected, and then incubated (T=35.5&ordm;C and RH=70%). On the 16th day of incubation, these eggs were transferred to a hatchery maintained at temperature and RH similar to those used in the incubator, where they were kept until hatching. The results showed that the mean number of eggshell pores changed among the three regions of the eggshell and egg weight classes, and also between the physical form of diets. Ingestion of pelleted diet increased eggshell thickness; however, hatchability and water loss percentages remained unchanged

Description of Karyotype of Kerodon acrobata, an endemic rodent in Brazilian Cerrado

Kerodon acrobata is a caviidae rodent endemic from Brazilian Cerrado. It was described only in 1997 and the data about it is very scarce. The aim of this work was to characterize the karyotype of K. acrobata. Giemsa staining, nucleolar organizer region (NOR) banding, C-positive heterochromatin banding and DAPI fluorescence were used in N metaphases of a specimen collected in Asa Branca Farm, in Aurora do Tocantins municipality, Tocantins state, Brazil. K. acrobata showed the same diploid number, fundamental number and chromosome morphology as Kerodon rupestris. But its NOR location and heterochromatin distribution patterns indicated a unique cytogenetic profile when compared to its sister species, emphasizing the evolutionary uniqueness of this relatively new and unknown species. This record also extends the distribution of this species northward