71 research outputs found
Dedifferentiation of Human Primary Thyrocytes into Multilineage Progenitor Cells without Gene Introduction
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
The presence of intermediate-mass black holes in globular clusters and their connection with extreme horizontal branch stars
By means of a multimass isotropic and spherical model that includes the
self-consistent treatment of a central intermediate-mass black hole (IMBH), the
influence of this black hole on the morphological and physical properties of
globular clusters is investigated. In agreement with recent numerical studies,
it is found that a cluster (with mass M) hosting an IMBH (with mass M_BH)
shows, outside the region of gravitational influence of the black hole, a
core-like profile resembling a King profile with concentration c < 2, although
with a slightly steeper behaviour in the core region. In particular, the core
logarithmic slope is s < 0.25 for reasonably low IMBH masses (M_BH < M/100),
and c decreases monotonically with M_BH. Completely power-law density profiles
(similar to, for example, those of collapsed clusters) are admitted only in the
presence of a black hole with an unrealistic M_BH > M. The mass range estimate
12s - 4.8 < log (M_BH/M)< -1.1c - 0.69, depending on the morphological
parameters, is deduced by considering a wide range of models. Applying this
estimate to a set of 39 globular clusters, it is found that NGC 2808, NGC 6388,
M80, M13, M62, M54 and G1 (in M31) probably host an IMBH. For them, the scaling
laws M_BH ~ 0.09(M/M_sol)^{0.7} M_sol and M_BH ~ 50[sigma/ (km s^-1)]^{1.2}
M_sol are identified from weighted least-squares fits. An important result of
this 'collective' study is that a strong correlation exists between the
presence of an extreme blue horizontal branch and the presence of an IMBH. In
particular, the presence of a central IMBH in M13 and NGC 6388 could explain
why these clusters possess extreme horizontal-branch stars, in contrast to
their 'second parameter' counterparts M3 and 47 Tuc.Comment: LaTeX, 15 pages, 8 figures, 4 tables included. Final version with new
G1 data. Accepted for publication on MNRAS. The definitive version is
available at www.blackwell-synergy.co
Percepção do enfermeiro sobre promoção da saúde na Unidade de Terapia Intensiva
Objetivou-se relatar a percepção dos enfermeiros sobre a promoção da saúde, descrever ações de promoção da saúde e identificar dificuldades na realização de atividades de promoção da saúde na Unidade de Terapia Intensiva (UTI). Trata-se de um estudo descritivo, exploratório, qualitativo realizado com 31 enfermeiros de duas UTIs adulto e uma UTI neonatal de hospital de referência em Fortaleza, Ceará, Brasil, entre julho e agosto de 2009, mediante questionário. Os dados foram analisados e categorizados a partir da análise de conteúdo de Bardin. Emergiram as seguintes categorias e subcategorias: Conceito de promoção da saúde: visão biomédica x visão holística de promoção da saúde; Ações de promoção da saúde; Comunicação e apoio emocional ao paciente/família; Promoção da saúde na UTI; Promoção da saúde com enfoque na educação em saúde; e Dificuldades para o desenvolvimento de ações de promoção da saúde
Significance of glycolytic metabolism-related protein expression in colorectal cancer, lymph node and hepatic metastasis
Background: Colorectal cancer (CRC) is one of the most common malignancies and a leading cause of cancer death worldwide. Most cancer cells display high rates of glycolysis with production of lactic acid, which is then exported to the microenvironment by monocarboxylate transporters (MCTs). The main aim of this study was to evaluate the significance of MCT expression in a comprehensive series of primary CRC cases, lymph node and hepatic metastasis.
Methods: Expressions of MCT1, MCT4, CD147 and GLUT1 were studied in human samples of CRC, lymph node and hepatic metastasis, by immunohistochemistry.
Results: All proteins were overexpressed in primary CRC, lymph node and hepatic metastasis, when compared with non-neoplastic tissue, with exception of MCT1 in lymph node and hepatic metastasis. MCT1 and MCT4 expressions were associated with CD147 and GLUT1 in primary CRC. These markers were associated with clinical pathological features, reflecting the putative role of these metabolism-related proteins in the CRC setting.
Conclusion: These findings provide additional evidence for the pivotal role of MCTs in CRC maintenance and progression, and support the use of MCTs as biomarkers and potential therapeutic targets in primary and metastatic CRC.This work was supported by the Fundação para a Ciência e a Tecnologia
(FCT) grant ref. PTDC/SAU-FCF/104347/2008, under the scope of ‘Programa
Operacional Temático Factores de Competitividade’ (COMPETE) of ‘Quadro
Comunitário de Apoio III’ and co-financed by the Fundo Europeu De Desenvolvimento
Regional (FEDER). Ricardo Amorim was recipient of the fellowship
SFRH/BD/98002/2013, from Fundação para a Ciência e a Tecnologia (FCT
Portugal).info:eu-repo/semantics/publishedVersio
Relativistic Dynamics and Extreme Mass Ratio Inspirals
It is now well-established that a dark, compact object (DCO), very likely a
massive black hole (MBH) of around four million solar masses is lurking at the
centre of the Milky Way. While a consensus is emerging about the origin and
growth of supermassive black holes (with masses larger than a billion solar
masses), MBHs with smaller masses, such as the one in our galactic centre,
remain understudied and enigmatic. The key to understanding these holes - how
some of them grow by orders of magnitude in mass - lies in understanding the
dynamics of the stars in the galactic neighbourhood. Stars interact with the
central MBH primarily through their gradual inspiral due to the emission of
gravitational radiation. Also stars produce gases which will subsequently be
accreted by the MBH through collisions and disruptions brought about by the
strong central tidal field. Such processes can contribute significantly to the
mass of the MBH and progress in understanding them requires theoretical work in
preparation for future gravitational radiation millihertz missions and X-ray
observatories. In particular, a unique probe of these regions is the
gravitational radiation that is emitted by some compact stars very close to the
black holes and which could be surveyed by a millihertz gravitational wave
interferometer scrutinizing the range of masses fundamental to understanding
the origin and growth of supermassive black holes. By extracting the
information carried by the gravitational radiation, we can determine the mass
and spin of the central MBH with unprecedented precision and we can determine
how the holes "eat" stars that happen to be near them.Comment: Update from the first version, 151 pages, accepted for publication @
Living Reviews in Relativit
Technical aspects and clinical limitations of sperm DNA fragmentation testing in male infertility: a global survey, current guidelines, and expert recommendations.
PURPOSE: Sperm DNA fragmentation (SDF) is a functional sperm abnormality that can impact reproductive potential, for which four assays have been described in the recently published sixth edition of the WHO laboratory manual for the examination and processing of human semen. The purpose of this study was to examine the global practices related to the use of SDF assays and investigate the barriers and limitations that clinicians face in incorporating these tests into their practice. MATERIALS AND METHODS: Clinicians managing male infertility were invited to complete an online survey on practices related to SDF diagnostic and treatment approaches. Their responses related to the technical aspects of SDF testing, current professional society guidelines, and the literature were used to generate expert recommendations via the Delphi method. Finally, challenges related to SDF that the clinicians encounter in their daily practice were captured. RESULTS: The survey was completed by 436 reproductive clinicians. Overall, terminal deoxynucleotidyl transferase deoxyuridine triphosphate Nick-End Labeling (TUNEL) is the most commonly used assay chosen by 28.6%, followed by the sperm chromatin structure assay (24.1%), and the sperm chromatin dispersion (19.1%). The choice of the assay was largely influenced by availability (70% of respondents). A threshold of 30% was the most selected cut-off value for elevated SDF by 33.7% of clinicians. Of respondents, 53.6% recommend SDF testing after 3 to 5 days of abstinence. Although 75.3% believe SDF testing can provide an explanation for many unknown causes of infertility, the main limiting factors selected by respondents are a lack of professional society guideline recommendations (62.7%) and an absence of globally accepted references for SDF interpretation (50.3%). CONCLUSIONS: This study represents the largest global survey on the technical aspects of SDF testing as well as the barriers encountered by clinicians. Unified global recommendations regarding clinician implementation and standard laboratory interpretation of SDF testing are crucial
Gender role orientation is associated with health-related quality of life differently among African-American, Hispanic, and White youth
PurposeThis study examined the association between gender role orientation (GRO) and health-related quality of life (HRQOL) in youth, and how this relationship may differ between males and females as well as among African-American, White, and Hispanic individuals. GRO has been reported to influence serious health outcomes including cancer, heart disease, mental illness, and mortality rates. However, few studies have examined the link between GRO and health outcomes for children, even though gender identity is formed in childhood.MethodsData were examined from 4824 participants in the Healthy Passages™ project, a population-based survey of fifth-grade children in three US metropolitan areas. Children reported their own HRQOL using the PedsQL and degree of female, male, and androgynous GRO using the Children's Sex Role Inventory.ResultsBased on structural equations analysis, male GRO was positively associated with HRQOL for all racial/ethnic groups, regardless of sex, whereas female GRO was associated with better HRQOL for Hispanic and White females and poorer HRQOL for Hispanic males. Androgynous GRO was associated with better HRQOL among Hispanic and White females, but not males nor African-Americans of either sex.ConclusionsRacial/ethnic differences emerged for female and androgynous, but not male, GROs. Hispanic males are the only group for which GRO (female) was associated with poorer HRQOL. Future research should find ways to help youth overcome negative effects on health from gender beliefs and behavior patterns with sensitivity to racial/ethnic membership
Protective Mechanisms for Depression among Racial/Ethnic Minority Youth: Empirical Findings, Issues, and Recommendations
We (1) review empirical studies that report findings regarding putative protective mechanisms when exposed to risk of depression in African American and Hispanic adolescents; (2) identify key protective mechanisms for different risk contexts that garner empirical support; (3) synthesize the mechanisms identified as protective against depression among racial/ethnic minority adolescents; and (4) discuss improved methods for advancing understanding of resilience against depression in minority youth. The studies were selected from PsycINFO searches that met the following inclusion criteria: participants between 12 and 21 years of age, inclusions of racial/ethnic minority members, examining protection through an interaction with a risk factor, and outcome measures of depression, depressed mood, or depressive symptomatology. We found 39 eligible studies; 13 of which included multiple racial/ethnic groups. The following were supported as protective mechanisms, at least preliminarily, for at least one racial/ethnic group and in at least one risk context: employment, extracurricular activities, father–adolescent closeness, familism, maternal support, attending predominately minority schools, neighborhood composition, non-parent support, parental inductive reasoning, religiosity, self-esteem, social activities, and positive early teacher relationships. To investigate protective mechanisms more comprehensively and accurately across individual, social, and community levels of influence, we recommend incorporating multilevel modeling or multilevel growth curve analyses and large diverse samples
Genotype-Phenotype correlation in Dravet Syndrome with SCN1A mutation increase efficiency of molecular diagnosis
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