Osteoblast response to disordered nanotopography

The ability to influence stem cell differentiation is highly desirable as it would help us improve clinical outcomes for patients in various aspects. Many different techniques to achieve this have previously been investigated. This concise study, however, has focused on the topography on which cells grow. Current uncemented orthopaedic implants can fail if the implant fails to bind to the surrounding bone and, typically, forms a soft tissue interface which reduces direct bone contact. Here, we look at the effect of a previously reported nanotopography that utilises nanodisorder to influence mesenchymal stromal cell (as may be found in the bone marrow) differentiation towards bone and to also exert this effect on mature osteoblasts (as may be found in the bone). As topography is a physical technique, it can be envisaged for use in a range of materials such as polymers and metals used in the manufacture of orthopaedic implants

A human pluripotent stem cell model to study the haploinsufficiency and dominant negative molecular mechanisms of Marfan Syndrome

O gene FBN1 codifica a proteína de matriz extracelular (MEC) fibrilina-1, principal componente estrutural das microfibrilas que compõem as fibras elásticas. Mutações neste gene foram relacionadas à ocorrência da Síndrome de Marfan (SMF), uma condição genética de caráter autossômico dominante, em que os sistemas cardiovascular, ósseo e ocular são afetados. Apesar de mais de 3.000 variantes patogênicas em FBN1 já terem sido descritas, não existem ainda muitas correlações genótipo-fenótipo bem estabelecidas para a síndrome, e dois mecanismos moleculares foram propostos e validados para explicar sua ocorrência: a haploinsuficiência (HI - i.e. baixa produção de fibrilina-1 selvagem) e a dominância negativa (DN - i.e. secreção e incorporação de uma proteína aberrante à MEC comprometendo a função da proteína normal) de fibrilina-1. Diferenças fenotípicas entre pacientes portadores de variantes HI ou DN foram reportadas, mas devido a diferenças de background genético entre os indivíduos e possível contribuição de genes modificadores na variabilidade fenotípica da síndrome, ainda não está claro o mecanismo de patogênese de cada classe de mutações. Diante disso, no presente trabalho geramos um modelo isogênico de células-tronco pluripotentes induzidas (hiPSCs) portando alterações em FBN1 do tipo HI ou DN e avaliamos suas consequências fenotípicas em cardiomiócitos diferenciados (iCMs). Conseguimos demonstrar que as alterações classificadas como HI levam ao decaimento do mRNA mutante e à ausência de produção de proteína, enquanto a alteração DN acarreta a produção e secreção de uma forma mutante da fibrilina-1, corroborando nossas expectativas. Apesar de não termos observado diferenças entre iCMs selvagens e mutantes provavelmente devido à imaturidade destas células, as linhagens geradas no presente trabalho podem ser utilizadas para que as consequências fenotípicas das diferentes classes de mutações em FBN1 em múltiplos tipos celulares possam ser investigadasThe FBN1 gene encodes the extracellular matrix (ECM) protein fibrillin-1, the major structural component of the microfibrils that form the elastic fibers. Mutations in this gene were related to the occurrence of Marfan Syndrome (MFS), a pleiotropic autosomal dominant connective tissue disorder whose clinical manifestations affect the cardiovascular, skeletal and ocular systems. Although more than 3,000 pathogenic variants in FBN1 have been described, there are no well-established genotype-phenotype correlations for the syndrome, with few exceptions, and two molecular mechanisms have been proposed and validated to explain its development: haploinsufficiency (HI - i.e. the lack of the regular amount of wild-type fibrillin-1) and dominant-negativity (DN - i.e. the disturbance of the ECM by an incorporated aberrant protein), and differences between groups of patients classified as HI or DN have been reported. Because patients have different genetic backgrounds and gene modifiers may play a role in the pathogenesis of the syndrome, the specific consequences of each group of mutations are not clear. To overcome these issues, we have successfully edited a hiPSC line from a healthy donor using CRISPR/Cas9 to generate isogenic HI and DN mutants for FBN1. We showed that the predicted HI mutations lead to mRNA decay and no protein production and that the DN variant result in the secretion of an aberrant fibrillin-1, as expected. Although we did not observe any distinct phenotypes when we compared hiPSC-derived cardiomyocytes from the different groups, possibly due to their immaturity, we can now take advantage of the plasticity of these stem cell lines to better understand the pathogenesis of Marfan Syndrome in different cell type

Monitoring cell line identity in collections of human induced pluripotent stem cells

The ability to reprogram somatic cells into induced pluripotent stem cells (hiPSCs) has led to the generation of large collections of cell lines from thousands of individuals with specific phenotypes, many of which will be shared among different research groups as invaluable tools for biomedical research. As hiPSC-based research involves extensive culture of many cell lines, the issue periodic cell line identification is particularly important to ensure that cell line identity remains accurate. Here we analyzed the different commercially available genotyping methods considering ease of in-house genotyping, cost and informativeness, and applied one of them in our workflow for hiPSC generation. We show that the chosen STR method was able to establish a unique DNA profile for each of the 35 individuals/hiPSC lines at the examined sites, as well as identify two discrepancies resulting from inadvertently exchanged samples. Our results highlight the importance of hiPSC line genotyping by an in-house method that allows periodic cell line identification and demonstrate that STR is a useful approach to supplement less frequent karyotyping and epigenetic evaluations. Keywords: Induced pluripotent stem cells, Genotyping, Cell line identification, Short tandem repeats, Quality contro

Resistência antimicrobiana em amostras de Salmonella hadar isoladas de carcaças de frango

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Evaluation of the cytotoxic and genotoxic effects of Sida planicaulis Cav extract using human neuroblastoma cell line SH-SY5Y

Sida planicaulis is a weed thought to have originated in Brazil, where it is present in abundant quantities, but also this plant is also found in south-central Florida, Indian Ocean Islands, and the Pacific Islands. Sida planicaulis produces neurotoxicity that adversely affects livestock breeding with heavy animal losses and consequent negative impact on Brazil’s economy. The aim of this study was to determine the chemical profile, cytotoxic and genotoxic effects of ethanolic extracts of S. planicaulis collected in winter (leaf extract) and summer (leaf extract and leaf + flower extract) using an in vitro model of human neuroblastoma cell line SH-SY5Y. Phytochemical screening demonstrated the presence of alkaloids, flavonoids, and apolar compounds. Rutin, quercetin, and swainsonine were detected by HPLC and GC/MS, respectively. Phosphorus, potassium, iron, and zinc were the inorganic elements found. Extracts produced cytotoxicity at all concentrations tested (7–4,000 μg/ml) as evidenced by the colorimetric assay [3-(4,5-dimethyl-thiazol-2-yl) −2,5-diphenyltetrazolium bromide (MTT)]. Based upon the alkaline comet assay extracts were found to induce genotoxicity at concentrations ranging from 0.437 to 7 μg/ml. DNA damage produced by extracts was affirmed using a modified comet assay with the enzymes Endo III and FPG in a concentration dependent manner. Further, enzyme-modified comet assay showed both oxidized purines and pyrimidines, and consequently oxidative stress was related to genomic instability and cell death. Data suggest that low concentrations of ethanolic extracts of S. planicaulis (different seasons) induced increased DNA damage related to oxidative stress and chemical composition

Synthesis and structure-activity relationship of nitrile-based cruzain inhibitors incorporating a trifluoroethylamine-based P2 amide replacement

The structure-activity relationship for nitrile-based cruzain inhibitors incorporating a P2 amide replacement based on trifluoroethylamine was explored by deconstruction of a published series of inhibitors. It was demonstrated that the P3 biphenyl substituent present in the published inhibitor structures could be truncated to phenyl with only a small loss of affinity. The effects of inverting the configuration of the P2 amide replacement and linking a benzyl substituent at P1 were observed to be strongly nonadditive. We show that plotting affinity against molecular size provides a means to visualize both the molecular size efficiency of structural transformations and the nonadditivity in the structure-activity relationship. We also show how the relationship between affinity and lipophilicity, measured by high-performance liquid chromatography with an immobilized artificial membrane stationary phase, may be used to normalize affinity with respect to lipophilicity

Work organization and the health of bank employees Organización del trabajo y salud de empleados del banco Organização do trabalho e saúde de trabalhadores bancários

The Brazilian banking sector has undergone an intense restructuring process and taken a leading position in the incorporation of new technologies and organizational innovations. Computerization in the industry, in association with forms of work organization, has resulted in changes that reflect on the workers' health. Based on the theoretical and methodological frameworks of historical and dialectical materialism, this qualitative study investigates the work conditions of bank employees in order to identify the extent to which changes in work organization interfere with these workers' health. Data were collected through interviews held with 11 bank employees. In addition to physical sickening due to occupational diseases directly related to work intensification, the results also show an increased incidence of mental suffering and a feeling of loss of professional identity. Work-related frustration, instability and concerns related to psychological pressure resulting from the need to achieve goals predominated in the reports.<br>La Banca Brasileña pasó por un intenso proceso de reestructuración y ha ocupado posiciones de liderazgo en la incorporación de nuevas tecnologías e innovaciones organizacionales. La informatización de la industria, junto con nuevas maneras de organización del trabajo, dio lugar a cambios que reflejaron en la salud de los trabajadores. Con base en el marco teórico y metodológico del materialismo histórico y dialéctico, este estudio cualitativo tuvo como objetivo investigar las condiciones laborales de los empleados del banco para identificar el grado en que los cambios en la organización del trabajo influyeron en la salud de los trabajadores. Los datos fueron recolectados a través de entrevistas con once empleados del banco. Los resultados mostraron, además de las enfermedades físicas profesionales directamente relacionadas con la intensificación del trabajo, aumento de la incidencia de sufrimiento mental y la sensación de pérdida de identidad profesional. Predominaron en las entrevistas sentimientos de frustración e inseguridad sobre el trabajo y la preocupación por la presión psicológica de la necesidad de logro de los objetivos.<br>O setor bancário brasileiro passou por intenso processo de reestruturação e ocupou posição de liderança na incorporação de novas tecnologias e inovações organizacionais. A informatização do setor, aliada às novas formas de organizar o trabalho, resultou em mudanças que refletiram na saúde dos trabalhadores. Fundamentado no referencial teórico metodológico do materialismo histórico-dialético, este estudo, de caráter qualitativo, teve por objetivo investigar as condições de trabalho de bancários, para identificar em que medida as mudanças na organização do trabalho interferiram na saúde daqueles trabalhadores. Os dados foram coletados através de entrevistas com onze bancários. Os resultados revelaram, além de adoecimentos de ordem física por doenças ocupacionais, diretamente relacionadas à intensificação do trabalho, o aumento da incidência de sofrimento mental e sentimento de perda de identidade profissional. Predominaram, nos depoimentos, sentimentos de frustração e insegurança em relação ao trabalho e preocupação com a pressão psicológica, derivada da necessidade de cumprimento de metas

Saúde mental do cuidador na instituição hospitalar

Este artigo tem como propósito verificar as experiências laborais dos profissionais de enfermagem e suas conseqüências para a saúde mental desses trabalhadores. A pesquisa foi realizada junto a profissionais de enfermagem do Instituto de Cardiologia de Porto Alegre, afastados de suas atividades durante o ano de 2003 por transtornos mentais e comportamentais (episódios depressivos breves, transtornos depressivos recorrentes e ansiedade generalizada), diagnosticados de acordo com o CID 10. Os dados foram coletados através de entrevistas individuais semi-estruturadas, e para sua interpretação foi utilizada a técnica de Análise de Conteúdos. Os resultados mostram que aspectos do trabalho contribuíram no processo de adoecer desses profissionais, como a natureza das atividades do cuidador, sobrecarga de tarefas e dificuldades de relacionamento interpessoal. Verificou-se ainda a percepção dos indivíduos quanto ao papel da organização frente ao seu afastamento, de forma a ampliar a discussão sobre gestão de pessoas e promoção de saúde no trabalho