Therapeutic implications of an enriched cancer stem-like cell population in a human osteosarcoma cell line

<p>Abstract</p> <p>Background</p> <p>Osteosarcoma is a bone-forming tumor of mesenchymal origin that presents a clinical pattern that is consistent with the cancer stem cell model. Cells with stem-like properties (CSCs) have been identified in several tumors and hypothesized as the responsible for the relative resistance to therapy and tumor relapses. In this study, we aimed to identify and characterize CSCs populations in a human osteosarcoma cell line and to explore their role in the responsiveness to conventional therapies.</p> <p>Methods</p> <p>CSCs were isolated from the human MNNG/HOS cell line using the sphere formation assay and characterized in terms of self-renewal, mesenchymal stem cell properties, expression of pluripotency markers and ABC transporters, metabolic activity and tumorigenicity. Cell's sensitivity to conventional chemotherapeutic agents and to irradiation was analyzed and related with cell cycle-induced alterations and apoptosis.</p> <p>Results</p> <p>The isolated CSCs were found to possess self-renewal and multipotential differentiation capabilities, express markers of pluripotent embryonic stem cells Oct4 and Nanog and the ABC transporters P-glycoprotein and BCRP, exhibit low metabolic activity and induce tumors in athymic mice. Compared with parental MNNG/HOS cells, CSCs were relatively more resistant to both chemotherapy and irradiation. None of the treatments have induced significant cell-cycle alterations and apoptosis in CSCs.</p> <p>Conclusions</p> <p>MNNG/HOS osteosarcoma cells contain a stem-like cell population relatively resistant to conventional chemotherapeutic agents and irradiation. This resistant phenotype appears to be related with some stem features, namely the high expression of the drug efflux transporters P-glycoprotein and BCRP and their quiescent nature, which may provide a biological basis for resistance to therapy and recurrence commonly observed in osteosarcoma.</p

Escala de avaliação de comportamento sexual de risco para adultos: tradução e adaptação transcultural para o português brasileiro Sexual risk behavior assessment schedule for adults: translation and cross-cultural adaptation into brazilian portuguese

INTRODUÇÃO: A investigação sistemática e detalhada dos comportamentos sexuais de risco constitui um dos principais alicerces para o desenvolvimento de pesquisas que visam à criação de intervenções eficazes para a prevenção do HIV. OBJETIVO: Descrever e discutir as etapas do processo de adaptação lingüístico-cultural das versões masculina e feminina da Escala de Avaliação de Comportamento Sexual de Risco para pacientes psiquiátricos para o português brasileiro pelo Projeto Interdisciplinar em Sexualidade, Saúde Mental e AIDS. MÉTODOS: Treinamento dos investigadores brasileiros no instrumento original, comparação da tradução e da retrotradução, seguida de adaptação lingüístico-cultural à luz da fase formativa do projeto, resultando em uma versão utilizada no treinamento dos entrevistadores brasileiros em entrevistas com pacientes psiquiátricos. Verificação lingüística, confiabilidade qualitativa do instrumento e confiabilidade entre entrevistadores constituíram as etapas complementares para a versão final do questionário. RESULTADOS: Exclusão e adição de seções e itens da escala, tanto nos aspectos conceituais quanto estruturais, foram realizadas, bem como a incorporação de achados resultantes da fase formativa do piloto da pesquisa e mudanças lingüísticas relativas ao registro empregado.<br>INTRODUCTION: A systematic and detailed investigation of sexual risk behaviors is one of the main foundations in the development of research projects aimed at designing effective interventions for HIV prevention. OBJECTIVE: This paper presents and discusses the stages of the translation and cross-cultural adaptation of male and female versions of the Sexual Risk Behavior Assessment Schedule for psychiatric patients into Brazilian Portuguese, carried out by the Interdisciplinary Project in Sexuality, Mental Health and AIDS. METHODS: Training of Brazilian investigators in the original questionnaire, comparison between translation and back-translation, followed by linguistic and cultural adaptation in the light of the project formative phase were performed, resulting in a version used to train Brazilian interviewers in interviewing psychiatric patients. Language verification, qualitative reliability and interrater reliability were used to complement the final version of the instrument. RESULTS: Elimination and addition of instrument sections and items covering both conceptual and structural aspects were carried out. Incorporation of formative findings from the pilot study and linguistic changes in terms of register were also performed

Practical guide for the use of biological therapies in rheumatoid arthritis - Update of December 2011

The authors review the practical aspects of biologi -cal therapy use for rheumatoid arthritis patients, commenting safety issues before and after treatment initiation and the best treatment strategies to optimize efficacy.publishersversionpublishe