66 research outputs found

    Dedifferentiation of Human Primary Thyrocytes into Multilineage Progenitor Cells without Gene Introduction

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    While identification and isolation of adult stem cells have potentially important implications, recent reports regarding dedifferentiation/reprogramming from differentiated cells have provided another clue to gain insight into source of tissue stem/progenitor cells. In this study, we developed a novel culture system to obtain dedifferentiated progenitor cells from normal human thyroid tissues. After enzymatic digestion, primary thyrocytes, expressing thyroglobulin, vimentin and cytokeratin-18, were cultured in a serum-free medium called SAGM. Although the vast majority of cells died, a small proportion (∼0.5%) survived and proliferated. During initial cell expansion, thyroglobulin/cytokeratin-18 expression was gradually declined in the proliferating cells. Moreover, sorted cells expressing thyroid peroxidase gave rise to proliferating clones in SAGM. These data suggest that those cells are derived from thyroid follicular cells or at least thyroid-committed cells. The SAGM-grown cells did not express any thyroid-specific genes. However, after four-week incubation with FBS and TSH, cytokeratin-18, thyroglobulin, TSH receptor, PAX8 and TTF1 expressions re-emerged. Moreover, surprisingly, the cells were capable of differentiating into neuronal or adipogenic lineage depending on differentiating conditions. In summary, we have developed a novel system to generate multilineage progenitor cells from normal human thyroid tissues. This seems to be achieved by dedifferentiation of thyroid follicular cells. The presently described culture system may be useful for regenerative medicine, but the primary importance will be as a tool to elucidate the mechanisms of thyroid diseases

    Prioritizing persons deprived of liberty in global guidelines for tuberculosis preventive treatment

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    Persons deprived of liberty (PDLs) are disproportionately impacted by tuberculosis, with high incidence rates and often limited access to diagnostics, treatment, and preventive measures. The World Health Organization (WHO) expanded its recommendations for tuberculosis preventive treatment (TPT) to many high-risk populations, but their guidance does not include PDL, and most low- and middle-income countries do not routinely provide edforthoseusedthroughoutthetext TPT in prisons. :Pleaseverifythatallentriesarecorrectlyabbreviated: Recent studies demonstrate high acceptability and completion rates of short-course TPT regimens in jails and prisons; costs of these regimens have been markedly reduced through international agreements, making this an opportune for further expanding their use. We argue that PDL should be a priority group for TPT in national guidelines and discuss implementation considerations and resource needs for TPT programs in carceral facilities. Scaling access to TPT for PDL is important for reducing disease and transmission in this population; it is also critical to advancing an equitable response to tuberculosis

    Voluntários do CVV: características sociodemográficas e psicológicas

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    The purpose was to identify social demographical and psychological characteristics on volunteers that offer, uninterruptedly, emotional support to the community in four CVV branches (Porto Alegre, Novo Hamburgo, Blumenau and Florianópolis) which are part of the 2Centro de Valorização da Vida", a nongovernmental organization recognized by the Brazilian Health Department as an agent of suicide prevention. One hundred volunteers participated, being submitted to a social demographical data formulary, Factorial Extroversion, Socialization and Neuroticism" Scales. Results show people who are well educated and economically stable which favors them to social work. In psychological terms, the scores obtained in Extroversion and Socialization factors suggest sensibility and capacity of adaptation and communication. In Neuroticism factor, the scores show tendency to independency and to experience stressful situations without emotional instability. The volunteers have psychological characteristics similar to general population and appreciated by CVV

    Model-driven approach to the implementation of context-aware applications using rule engines

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    This paper aims at demonstrating that the Model-Driven Architecture (MDA) approach to transformation is suitable to cope with the abstraction gap between the specification of application rules for context-aware applications and the implementation of these rules using rule engines. This paper reports on the transformation of Event-Condition-Action (ECA) rules onto rules that can be executed by the Jess rules engine. We have applied the MDA approach to define this transformation, by specifying it in terms of mappings between elements of the ECA Domain-specific Language (ECA-DL), which is the language we developed to represent ECA rules, and the Jess metamodel. The transformation was fully specified, implemented using the Atlas Transformation Language (ATL) and tested with a simple example

    Telomerase activity and telomerase subunits gene expression patterns in neuroblastoma: A molecular and immunohistochemical study establishing prognostic tools for fresh-frozen and paraffin-embedded tissues

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    Purpose: We have recently demonstrated that telomerase activity (TA) is an independent prognostic factor in neuroblastomas. in the present study, the prognostic impact of TA and gene expression of the three major telomerase subunits is evaluated by molecular and immunohistochemical techniques in fresh-frozen and paraffin-embedded tissues. Patients and Methods: One hundred thirty-three neuroblastomas of all stages were analyzed for TA, The TA levels of 75 neuroblastoma cases were correlated with gene expression of telomerase subunits hTRT, human telomerase RNA (hTR), and telomerase protein 1 (TP1) by quantitative reverse transcriptase polymerase chain reaction (RT-PCR), using an innovative approach on the LightCycler instrument (Roche Diagnostics, Mannheim, Germany). For selected cases, the applicability of RT-PCR and immunohistochemistry for hTRT expression analysis was investigated in paraffin-embedded tissues. TA and subunit expression patterns were correlated with traditional prognostic indicators and disease outcome. Results: TA was present in a total of 39 (29.3%) of 133 neuroblastomas and in 31 (29.8%) of 104 initial neuroblastomas without cytotoxic pretreatment, TA was significantly correlated with both event-free and overall survival (P <.0001), Furthermore, we found a significant correlation between expression levels of TA and hTRT (P <.0001) as well as hTR (P <.001), Multivariate analysis revealed only TA and tumor stage but not serum lactate dehydrogenase, MYCN amplification, or age at diagnosis as independent prognostic factors. Conclusion: The significant correlation with clinical outcome strongly recommends that analysis of TA be incorporated into the clinical investigation of each individual neuroblastoma at the time of diagnosis. Because the mere presence or absence of TA without further quantification is sufficient basis for predicting disease outcome, the telomeric repeat amplification protocol assay could be complemented with but not replaced by analysis of hTRT or hTR expression. J Clin Oncol 18:2582-2592, (C) 2000 by American Society of Clinical Oncology
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