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1.
Mol Cell ; 80(2): 279-295.e8, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33065020

RESUMO

The PTEN tumor suppressor controls cell death and survival by regulating functions of various molecular targets. While the role of PTEN lipid-phosphatase activity on PtdIns(3,4,5)P3 and inhibition of PI3K pathway is well characterized, the biological relevance of PTEN protein-phosphatase activity remains undefined. Here, using knockin (KI) mice harboring cancer-associated and functionally relevant missense mutations, we show that although loss of PTEN lipid-phosphatase function cooperates with oncogenic PI3K to promote rapid mammary tumorigenesis, the additional loss of PTEN protein-phosphatase activity triggered an extensive cell death response evident in early and advanced mammary tumors. Omics and drug-targeting studies revealed that PI3Ks act to reduce glucocorticoid receptor (GR) levels, which are rescued by loss of PTEN protein-phosphatase activity to restrain cell survival. Thus, we find that the dual regulation of GR by PI3K and PTEN functions as a rheostat that can be exploited for the treatment of PTEN loss-driven cancers.


Assuntos
Neoplasias Mamárias Animais/metabolismo , Neoplasias Mamárias Animais/patologia , PTEN Fosfo-Hidrolase/metabolismo , Receptores de Glucocorticoides/metabolismo , Animais , Carcinogênese , Morte Celular , Linhagem Celular Tumoral , Proliferação de Células , Dexametasona/farmacologia , Feminino , Humanos , Isoenzimas/metabolismo , Camundongos , Modelos Biológicos , Mutação/genética , Organoides/patologia , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Estabilidade Proteica , Proteoma/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
2.
Am J Epidemiol ; 191(7): 1153-1173, 2022 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-35279711

RESUMO

The Collaborative Cohort of Cohorts for COVID-19 Research (C4R) is a national prospective study of adults comprising 14 established US prospective cohort studies. Starting as early as 1971, investigators in the C4R cohort studies have collected data on clinical and subclinical diseases and their risk factors, including behavior, cognition, biomarkers, and social determinants of health. C4R links this pre-coronavirus disease 2019 (COVID-19) phenotyping to information on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and acute and postacute COVID-related illness. C4R is largely population-based, has an age range of 18-108 years, and reflects the racial, ethnic, socioeconomic, and geographic diversity of the United States. C4R ascertains SARS-CoV-2 infection and COVID-19 illness using standardized questionnaires, ascertainment of COVID-related hospitalizations and deaths, and a SARS-CoV-2 serosurvey conducted via dried blood spots. Master protocols leverage existing robust retention rates for telephone and in-person examinations and high-quality event surveillance. Extensive prepandemic data minimize referral, survival, and recall bias. Data are harmonized with research-quality phenotyping unmatched by clinical and survey-based studies; these data will be pooled and shared widely to expedite collaboration and scientific findings. This resource will allow evaluation of risk and resilience factors for COVID-19 severity and outcomes, including postacute sequelae, and assessment of the social and behavioral impact of the pandemic on long-term health trajectories.


Assuntos
COVID-19 , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , Estudos de Coortes , Humanos , Pessoa de Meia-Idade , Pandemias , Estudos Prospectivos , SARS-CoV-2 , Estados Unidos/epidemiologia , Adulto Jovem
3.
PLoS Comput Biol ; 17(9): e1008513, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34529665

RESUMO

The PI3K/MTOR signalling network regulates a broad array of critical cellular processes, including cell growth, metabolism and autophagy. The mechanistic target of rapamycin (MTOR) kinase functions as a core catalytic subunit in two physically and functionally distinct complexes mTORC1 and mTORC2, which also share other common components including MLST8 (also known as GßL) and DEPTOR. Despite intensive research, how mTORC1 and 2 assembly and activity are coordinated, and how they are functionally linked remain to be fully characterized. This is due in part to the complex network wiring, featuring multiple feedback loops and intricate post-translational modifications. Here, we integrate predictive network modelling, in vitro experiments and -omics data analysis to elucidate the emergent dynamic behaviour of the PI3K/MTOR network. We construct new mechanistic models that encapsulate critical mechanistic details, including mTORC1/2 coordination by MLST8 (de)ubiquitination and the Akt-to-mTORC2 positive feedback loop. Model simulations validated by experimental studies revealed a previously unknown biphasic, threshold-gated dependence of mTORC1 activity on the key mTORC2 subunit SIN1, which is robust against cell-to-cell variation in protein expression. In addition, our integrative analysis demonstrates that ubiquitination of MLST8, which is reversed by OTUD7B, is regulated by IRS1/2. Our results further support the essential role of MLST8 in enabling both mTORC1 and 2's activity and suggest MLST8 as a viable therapeutic target in breast cancer. Overall, our study reports a new mechanistic model of PI3K/MTOR signalling incorporating MLST8-mediated mTORC1/2 formation and unveils a novel regulatory linkage between mTORC1 and mTORC2.


Assuntos
Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Linhagem Celular , Peptídeos e Proteínas de Sinalização Intracelular , Alvo Mecanístico do Complexo 2 de Rapamicina/química , Reprodutibilidade dos Testes , Transdução de Sinais , Homólogo LST8 da Proteína Associada a mTOR/metabolismo
4.
Mol Cell Proteomics ; 19(11): 1777-1789, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32759169

RESUMO

Amino acid hydroxylation is a common post-translational modification, which generally regulates protein interactions or adds a functional group that can be further modified. Such hydroxylation is currently considered irreversible, necessitating the degradation and re-synthesis of the entire protein to reset the modification. Here we present evidence that the cellular machinery can reverse FIH-mediated asparagine hydroxylation on intact proteins. These data suggest that asparagine hydroxylation is a flexible and dynamic post-translational modification akin to modifications involved in regulating signaling networks, such as phosphorylation, methylation and ubiquitylation.


Assuntos
Asparagina/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Oxigenases de Função Mista/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas Repressoras/metabolismo , Canais de Cátion TRPV/metabolismo , Tanquirases/metabolismo , Sequência de Aminoácidos , Linhagem Celular Tumoral , Humanos , Hidroxilação , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Cinética , Espectrometria de Massas , Metilação , Oxigenases de Função Mista/genética , Fosforilação , Ligação Proteica , Proteínas Repressoras/genética , Transdução de Sinais , Canais de Cátion TRPV/genética , Tanquirases/genética , Ubiquitinação
5.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203293

RESUMO

The PI3K/mTOR signalling pathway plays a central role in the governing of cell growth, survival and metabolism. As such, it must integrate and decode information from both external and internal sources to guide efficient decision-making by the cell. To facilitate this, the pathway has evolved an intricate web of complex regulatory mechanisms and elaborate crosstalk with neighbouring signalling pathways, making it a highly non-linear system. Here, we describe the mechanistic biological details that underpin these regulatory mechanisms, covering a multitude of negative and positive feedback loops, feed-forward loops, competing protein interactions, and crosstalk with major signalling pathways. Further, we highlight the non-linear and dynamic network behaviours that arise from these regulations, uncovered through computational and experimental studies. Given the pivotal role of the PI3K/mTOR network in cellular homeostasis and its frequent dysregulation in pathologies including cancer and diabetes, a coherent and systems-level understanding of the complex regulation and consequential dynamic signalling behaviours within this network is imperative for advancing biology and development of new therapeutic approaches.


Assuntos
Neoplasias/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Animais , Homeostase , Humanos , Neoplasias/genética , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
6.
Cell Commun Signal ; 18(1): 13, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31987043

RESUMO

BACKGROUND: Triple negative breast cancer (TNBC) accounts for 16% of breast cancers and represents an aggressive subtype that lacks targeted therapeutic options. In this study, mass spectrometry (MS)-based tyrosine phosphorylation profiling identified aberrant FGFR3 activation in a subset of TNBC cell lines. This kinase was therefore evaluated as a potential therapeutic target. METHODS: MS-based tyrosine phosphorylation profiling was undertaken across a panel of 24 TNBC cell lines. Immunoprecipitation and Western blot were used to further characterize FGFR3 phosphorylation. Indirect immunofluorescence and confocal microscopy were used to determine FGFR3 localization. The selective FGFR1-3 inhibitor, PD173074 and siRNA knockdowns were used to characterize the functional role of FGFR3 in vitro. The TCGA and Metabric breast cancer datasets were interrogated to identify FGFR3 alterations and how they relate to breast cancer subtype and overall patient survival. RESULTS: High FGFR3 expression and phosphorylation were detected in SUM185PE cells, which harbor a FGFR3-TACC3 gene fusion. Low FGFR3 phosphorylation was detected in CAL51, MFM-223 and MDA-MB-231 cells. In SUM185PE cells, the FGFR3-TACC3 fusion protein contributed the majority of phosphorylated FGFR3, and largely localized to the cytoplasm and plasma membrane, with staining at the mitotic spindle in a small subset of cells. Knockdown of the FGFR3-TACC3 fusion and wildtype FGFR3 in SUM185PE cells decreased FRS2, AKT and ERK phosphorylation, and induced cell death. Knockdown of wildtype FGFR3 resulted in only a trend for decreased proliferation. PD173074 significantly decreased FRS2, AKT and ERK activation, and reduced SUM185PE cell proliferation. Cyclin A and pRb were also decreased in the presence of PD173074, while cleaved PARP was increased, indicating cell cycle arrest in G1 phase and apoptosis. Knockdown of FGFR3 in CAL51, MFM-223 and MDA-MB-231 cells had no significant effect on cell proliferation. Interrogation of public datasets revealed that increased FGFR3 expression in breast cancer was significantly associated with reduced overall survival, and that potentially oncogenic FGFR3 alterations (eg mutation and amplification) occur in the TNBC/basal, luminal A and luminal B subtypes, but are rare. CONCLUSIONS: These results indicate that targeting FGFR3 may represent a therapeutic option for TNBC, but only for patients with oncogenic FGFR3 alterations, such as the FGFR3-TACC3 fusion. Video abstract.


Assuntos
Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Pontos de Checagem da Fase G1 do Ciclo Celular , Humanos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Fosforilação , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Transdução de Sinais , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/fisiopatologia
7.
Respir Res ; 20(1): 269, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31791337

RESUMO

Impaired single breath carbon monoxide diffusing capacity (DLCO) is associated with emphysema. Small airways disease (SAD) may be a precursor lesion to emphysema, but the relationship between SAD and DLCO is undescribed. We hypothesized that in mild COPD, functional SAD (fSAD) defined by computed tomography (CT) and Parametric Response Mapping methodology would correlate with impaired DLCO. Using data from ever-smokers in the COPDGene cohort, we established that fSAD correlated significantly with lower DLCO among both non-obstructed and GOLD 1-2 subjects. The relationship between DLCO with CT-defined emphysema was present in all GOLD stages, but most prominent in severe disease. TRIAL REGISTRATION: NCT00608764. Registry: COPDGene. Registered 06 February 2008, retrospectively registered.


Assuntos
Obstrução das Vias Respiratórias/diagnóstico por imagem , Bronquíolos/patologia , Doença Pulmonar Obstrutiva Crônica/genética , Enfisema Pulmonar/genética , Idoso , Obstrução das Vias Respiratórias/patologia , Remodelação das Vias Aéreas/fisiologia , Bronquíolos/anormalidades , Monóxido de Carbono/metabolismo , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Capacidade de Difusão Pulmonar , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Enfisema Pulmonar/diagnóstico por imagem , Análise de Regressão , Testes de Função Respiratória , Estudos Retrospectivos , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X/métodos
8.
Respir Res ; 20(1): 254, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31718676

RESUMO

BACKGROUND: Pulmonary and systemic inflammation are central features of chronic obstructive pulmonary disease (COPD). Previous studies have demonstrated relationships between biologically active extracellular matrix components, or matrikines, and COPD pathogenesis. We studied the relationships between the matrikine acetyl-proline-glycine-proline (AcPGP) in sputum and plasma and clinical features of COPD. METHODS: Sputum and plasma samples were obtained from COPD participants in the SPIROMICS cohort at enrollment. AcPGP was isolated using solid phase extraction and measured by mass spectrometry. Demographics, spirometry, quality of life questionnaires, and quantitative computed tomography (CT) imaging with parametric response mapping (PRM) were obtained at baseline. Severe COPD exacerbations were recorded at 1-year of prospective follow-up. We used linear and logistic regression models to measure associations between AcPGP and features of COPD, and Kaplan-Meier analyses to measure time-to-first severe exacerbation. RESULTS: The 182 COPD participants in the analysis were 66 ± 8 years old, 62% male, 84% White race, and 39% were current smokers. AcPGP concentrations were 0.61 ± 1.89 ng/mL (mean ± SD) in sputum and 0.60 ± 1.13 ng/mL in plasma. In adjusted linear regression models, sputum AcPGP was associated with FEV1/FVC, spirometric GOLD stage, PRM-small airways disease, and PRM-emphysema. Sputum AcPGP also correlated with severe AECOPD, and elevated sputum AcPGP was associated with shorter time-to-first severe COPD exacerbation. In contrast, plasma AcPGP was not associated with symptoms, pulmonary function, or severe exacerbation risk. CONCLUSIONS: In COPD, sputum but not plasma AcPGP concentrations are associated with the severity of airflow limitation, small airways disease, emphysema, and risk for severe AECOPD at 1-year of follow-up. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01969344 (SPIROMICS).


Assuntos
Glicina/sangue , Prolina/sangue , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Espirometria/métodos , Escarro/metabolismo , Idoso , Biomarcadores/sangue , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Escarro/química
9.
PLoS Comput Biol ; 14(6): e1006192, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29920512

RESUMO

Prediction of drug combinations that effectively target cancer cells is a critical challenge for cancer therapy, in particular for triple-negative breast cancer (TNBC), a highly aggressive breast cancer subtype with no effective targeted treatment. As signalling pathway networks critically control cancer cell behaviour, analysis of signalling network activity and crosstalk can help predict potent drug combinations and rational stratification of patients, thus bringing therapeutic and prognostic values. We have previously showed that the non-receptor tyrosine kinase PYK2 is a downstream effector of EGFR and c-Met and demonstrated their crosstalk signalling in basal-like TNBC. Here we applied a systems modelling approach and developed a mechanistic model of the integrated EGFR-PYK2-c-Met signalling network to identify and prioritize potent drug combinations for TNBC. Model predictions validated by experimental data revealed that among six potential combinations of drug pairs targeting the central nodes of the network, including EGFR, c-Met, PYK2 and STAT3, co-targeting of EGFR and PYK2 and to a lesser extent of EGFR and c-Met yielded strongest synergistic effect. Importantly, the synergy in co-targeting EGFR and PYK2 was linked to switch-like cell proliferation-associated responses. Moreover, simulations of patient-specific models using public gene expression data of TNBC patients led to predictive stratification of patients into subgroups displaying distinct susceptibility to specific drug combinations. These results suggest that mechanistic systems modelling is a powerful approach for the rational design, prediction and prioritization of potent combination therapies for individual patients, thus providing a concrete step towards personalized treatment for TNBC and other tumour types.


Assuntos
Antineoplásicos , Receptores ErbB/metabolismo , Quinase 2 de Adesão Focal/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Transdução de Sinais , Neoplasias de Mama Triplo Negativas , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Biologia Computacional , Bases de Dados Genéticas , Sinergismo Farmacológico , Feminino , Perfilação da Expressão Gênica , Humanos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo
10.
Semin Cell Dev Biol ; 50: 85-94, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26481970

RESUMO

The notion of feedback is fundamental for understanding signal transduction networks. Feedback loops attenuate or amplify signals, change the network dynamics and modify the input-output relationships between the signal and the target. Negative feedback provides robustness to noise and adaptation to perturbations, but as a double-edged sword can prevent effective pathway inhibition by a drug. Positive feedback brings about switch-like network responses and can convert analog input signals into digital outputs, triggering cell fate decisions and phenotypic changes. We show how a multitude of protein-protein interactions creates hidden feedback loops in signal transduction cascades. Drug treatments that interfere with feedback regulation can cause unexpected adverse effects. Combinatorial molecular interactions generated by pathway crosstalk and feedback loops often bypass the block caused by targeted therapies against oncogenic mutated kinases. We discuss mechanisms of drug resistance caused by network adaptations and suggest that development of effective drug combinations requires understanding of how feedback loops modulate drug responses.


Assuntos
Antineoplásicos/uso terapêutico , Retroalimentação Fisiológica , Neoplasias/tratamento farmacológico , Transdução de Sinais , Animais , Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Retroalimentação Fisiológica/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Humanos , Transdução de Sinais/efeitos dos fármacos
11.
Brief Bioinform ; 17(3): 479-93, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26210356

RESUMO

Post-translational modification of cellular proteins by ubiquitin is a pivotal regulatory event that controls not only protein degradation, but also a variety of non-proteolytic functions. Ubiquitination is involved in a broad array of physiological processes, and its dysregulation has been associated with many human diseases, including neuronal disorders and cancers. Ubiquitin-mediated signalling has thus come to the forefront of biomedical research. It is increasingly apparent that ubiquitination is a highly complex and dynamic process, evidenced by a myriad of ways of ubiquitin chain formation, tightly regulatory mechanisms involving E3 ligases and deubiquitinating enzymes and extensive crosstalk with other post-translational modifications. To unravel the complexity of ubiquitination and understand the dynamic properties of ubiquitin-mediated signalling are challenging, but critical topics in ubiquitin research, which will undoubtedly benefit our effort in developing strategies that could target ubiquitin signalling for therapeutics. Computational modelling and model-based approaches are emerging as promising tools that help tackle the complexity and provide useful frameworks for quantitative and dynamical analysis of ubiquitin signalling. In this article, I will discuss recent advances in our understanding of the dynamic behaviour of ubiquitination from both theoretical and experimental studies, and aspects of ubiquitin signalling that may have major dynamical consequences. It is expected the discussed issues will be of relevant interest to both the ubiquitin and systems biology fields.


Assuntos
Ubiquitina/metabolismo , Humanos , Processamento de Proteína Pós-Traducional , Proteínas , Biologia de Sistemas , Ubiquitinação
12.
Brief Bioinform ; 17(4): 593-602, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26443615

RESUMO

The detailed, atomistic-level understanding of molecular signaling along the tumor-suppressive Hippo signaling pathway that controls tissue homeostasis by balancing cell proliferation and death through apoptosis is a promising avenue for the discovery of novel anticancer drug targets. The activation of kinases such as Mammalian STE20-Like Protein Kinases 1 and 2 (MST1 and MST2)-modulated through both homo- and heterodimerization (e.g. interactions with Ras association domain family, RASSF, enzymes)-is a key upstream event in this pathway and remains poorly understood. On the other hand, RASSFs (such as RASSF1A or RASSF5) act as important apoptosis activators and tumor suppressors, although their exact regulatory roles are also unclear. We present recent molecular studies of signaling along the Ras-RASSF-MST pathway, which controls growth and apoptosis in eukaryotic cells, including a variety of modern molecular modeling and simulation techniques. Using recently available structural information, we discuss the complex regulatory scenario according to which RASSFs perform dual signaling functions, either preventing or promoting MST2 activation, and thus control cell apoptosis. Here, we focus on recent studies highlighting the special role being played by the specific interactions between the helical Salvador/RASSF/Hippo (SARAH) domains of MST2 and RASSF1a or RASSF5 enzymes. These studies are crucial for integrating atomistic-level mechanistic information about the structures and conformational dynamics of interacting proteins, with information available on their system-level functions in cellular signaling.


Assuntos
Ligação Proteica , Animais , Apoptose , Modelos Moleculares , Proteínas Serina-Treonina Quinases , Transdução de Sinais
13.
BMC Med Genet ; 19(1): 134, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30068317

RESUMO

BACKGROUND: The aim of this study is to identify genetic loci associated with post-bronchodilator FEV1/FVC and FEV1, and develop a multi-gene predictive model for lung function in COPD. METHODS: Genome-wide association study (GWAS) of post-bronchodilator FEV1/FVC and FEV1 was performed in 1645 non-Hispanic White European descent smokers. RESULTS: A functional rare variant in SERPINA1 (rs28929474: Glu342Lys) was significantly associated with post-bronchodilator FEV1/FVC (p = 1.2 × 10- 8) and FEV1 (p = 2.1 × 10- 9). In addition, this variant was associated with COPD (OR = 2.3; p = 7.8 × 10- 4) and severity (OR = 4.1; p = 0.0036). Heterozygous subjects (CT genotype) had significantly lower lung function and higher percentage of COPD and more severe COPD than subjects with the CC genotype. 8.6% of the variance of post-bronchodilator FEV1/FVC can be explained by SNPs in 10 genes with age, sex, and pack-years of cigarette smoking (P <  2.2 × 10- 16). CONCLUSIONS: This study is the first to show genome-wide significant association of rs28929474 in SERPINA1 with lung function. Of clinical importance, heterozygotes of rs28929474 (4.7% of subjects) have significantly reduced pulmonary function, demonstrating a major impact in smokers. The multi-gene model is significantly associated with CT-based emphysema and clinical outcome measures of severity. Combining genetic information with demographic and environmental factors will further increase the predictive power for assessing reduced lung function and COPD severity.


Assuntos
Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/genética , Fumar/genética , Idoso , Feminino , Loci Gênicos/genética , Estudo de Associação Genômica Ampla/métodos , Genótipo , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Testes de Função Respiratória/métodos , Fumantes , População Branca/genética , alfa 1-Antitripsina/genética
14.
J Microsc ; 272(1): 25-34, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29944731

RESUMO

This work presents a methodology combining SEM, EDS, conventional EBSD, and transmission-EBSD to analyse a recrystallised Zircaloy-4 sheet and cold-worked stress-relieved (CWSR) Zircaloy-4 cladding in unprecedented detail. Second-phase precipitates (SPPs) in Zircaloy-4 specimens were revealed after chemical polishing using a solution containing hydrofluoric acid (HF). Pitting corrosion of Zircaloy-4 specimens was revealed after electropolishing using an electrolyte containing HClO4 . A zirconium coupon without SPPs was used to confirm the chemical response of SPPs on surface morphology. Intrinsic features of cold-worked Zircaloy-4 such as relatively small grain sizes, high dislocation density, and complex microstructure make it significantly more difficult to collect excellent EBSD results compared to recrystallised Zircaloy-4. The fine hydride structure of as-hydrided CWSR Zircaloy-4 cladding further increases the level of challenge on EBSD analysis. LAY DESCRIPTION: We present a methodology combining multiple microscopic methods to analyse a recrystallised Zircaloy-4 sheet and cold-worked stress-relieved (CWSR) Zircaloy-4 cladding, important alloys of structural materials widely used in nuclear application, and emphasis on the challenge of acquiring a satisfactory electron backscatter diffraction (EBSD) result of CWSR Zircaloy-4 cladding material in great details. EBSD is a powerful technique to characterise the crystallographic distribution and lattice type of conductive crystalline materials, especially for a highly textured material like CWSR Zircaloy-4 alloy. However, zirconium alloys are known to be one of the most difficult materials to prepare for EBSD characterisation. We point out that the configuration of the microstructure of the specimen cause the challenge in the EBSD sample preparations. Moreover, the occurrence of tiny zirconium hydride precipitates in Zircaloy-4 increases the difficulty. We believe that the information of the EBSD sample preparation related results in this paper can provide researchers and scientists in this community a useful reference to speed up the EBSD sample preparation of CWSR Zircaloy-4 cladding material and to expect the corresponding EBSD results.

15.
Phys Rev Lett ; 118(16): 165001, 2017 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-28474938

RESUMO

We investigate a new laser-driven spherically convergent plasma fusion scheme (SCPF) that can produce thermonuclear neutrons stably and efficiently. In the SCPF scheme, laser beams of nanosecond pulse duration and 10^{14}-10^{15} W/cm^{2} intensity uniformly irradiate the fuel layer lined inside a spherical hohlraum. The fuel layer is ablated and heated to expand inwards. Eventually, the hot fuel plasmas converge, collide, merge, and stagnate at the central region, converting most of their kinetic energy to internal energy, forming a thermonuclear fusion fireball. With the assumptions of steady ablation and adiabatic expansion, we theoretically predict the neutron yield Y_{n} to be related to the laser energy E_{L}, the hohlraum radius R_{h}, and the pulse duration τ through a scaling law of Y_{n}∝(E_{L}/R_{h}^{1.2}τ^{0.2})^{2.5}. We have done experiments at the ShengGuangIII-prototype facility to demonstrate the principle of the SCPF scheme. Some important implications are discussed.

16.
PLoS Comput Biol ; 12(10): e1005051, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27716844

RESUMO

RASSF enzymes act as key apoptosis activators and tumor suppressors, being downregulated in many human cancers, although their exact regulatory roles remain unknown. A key downstream event in the RASSF pathway is the regulation of MST kinases, which are main effectors of RASSF-induced apoptosis. The regulation of MST1/2 includes both homo- and heterodimerization, mediated by helical SARAH domains, though the underlying molecular interaction mechanism is unclear. Here, we study the interactions between RASSF1A, RASSF5, and MST2 SARAH domains by using both atomistic molecular simulation techniques and experiments. We construct and study models of MST2 homodimers and MST2-RASSF SARAH heterodimers, and we identify the factors that control their high molecular stability. In addition, we also analyze both computationally and experimentally the interactions of MST2 SARAH domains with a series of synthetic peptides particularly designed to bind to it, and hope that our approach can be used to address some of the challenging problems in designing new anti-cancer drugs.


Assuntos
Proteínas de Transporte/química , Proteínas de Transporte/ultraestrutura , Inibidor de Quinase Dependente de Ciclina p15/química , Inibidor de Quinase Dependente de Ciclina p15/ultraestrutura , Proteínas de Drosophila/química , Proteínas de Drosophila/ultraestrutura , Simulação de Acoplamento Molecular , Sítios de Ligação , Dimerização , Ativação Enzimática , Ligação Proteica , Conformação Proteica , Domínios Proteicos
17.
Stat Med ; 36(3): 416-425, 2017 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-27873342

RESUMO

Even though consistency is an important issue in multi-regional clinical trials and inconsistency is often anticipated, solutions for handling inconsistency are rare. If a region's treatment effects are inconsistent with that of the other regions, pooling all the regions to estimate the overall treatment effect may not be reasonable. Unlike the multiple center clinical trials conducted in the USA and Europe, in multi-regional clinical trials, different regional regulatory agencies may have their own ways to interpret data and approve new drugs. It is therefore practical to consider the case in which the data from the region with the minimal observed treatment effect is excluded from the analysis in order to attain the regulatory approval of the study drug. Under such cases, what is the appropriate statistical approach for the remaining regions? We provide a solution first formulated within the fixed effects framework and then extend it to discrete random effects models. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Interpretação Estatística de Dados , Ensaios Clínicos Controlados Aleatórios como Assunto , Aprovação de Drogas/métodos , Humanos , Modelos Estatísticos , Estudos Multicêntricos como Assunto/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Resultado do Tratamento
18.
Beijing Da Xue Xue Bao Yi Xue Ban ; 49(4): 643-647, 2017 08 18.
Artigo em Zh | MEDLINE | ID: mdl-28816281

RESUMO

OBJECTIVE: To examine the effects of perioperative intravenous administration of flurbiprofen axetil (FA) on pain associated with transrectal ultrasound-guided prostate biopsy. METHODS: This was a randomized,controlled study. Eighty-one patients who underwent 12 core prostate biopsy were included in the study. The patients were randomly assigned to one of three groups (n=27 in each) by type of procedure during prostate biopsy. Group intrarectal local anesthesia (IRLA) received intrarectal 5% (0.05 g/L) lidocaine gel 60 mg, 5 minutes before the procedure alone; Group FA received intravenous flurbiprofen axetil (1 mg/kg) 1 hour before the procedure; Group IRLA+FA received intrarectal 5% lidocaine gel 60 mg, 5 minutes before the procedure and intravenous flurbiprofen axetil (1 mg/kg) 1 hour before the procedure. The patients were asked to score the pain by using visual analogue scale (VAS) in 4 situations,including when the probe was inserted (VASI),during anesthesia (VAS II),during biopsy (VAS III) and 20 minutes after biopsy (VAS IV). The findings were evaluated with analysis of variance,and the Tukey post hoc test was followed with an overall 2-tailed significance level at α =0.05. P1, P value between Group IRLA and Group FA; P2, P value between Group FA and Group IRLA +FA, P3, P value between Group IRLA and Group IRLA +FA. The bonferroni method was used to adjust the test level, α=0.017,a P value of less than 0.017 was accepted as the threshold for statistical significance. RESULTS: No major complications,including sepsis and severe rectal bleeding,were noted in any patient. There were no differences in general condition of the patients before procedure among the 3 groups. There were statistically significant differences in VAS scores among the 3 groups in VAS II (5.7±2.2, 3.0±1.5,3.3±1.9,respectively,P=0.012) and VAS III (6.7±2.3,3.0±2.1,2.9±1.6,respectively,P=0.001). There were no differences in the pain scores among the 3 groups during probe insertion (VAS I, 3.2±1.0,4.1±2.1,4.2±1.7, respectively,P=5.752) and 20 minutes after biopsy (VAS IV, 1.4±2.1,1.0±0.9,1.1±0.7,respectively,P=3.772). Between-column differences among the 3 groups were VAS II (P1=0.007,P2=5.655,P3=0.001,respectively) and VAS III(P1=0.008,P2=7.517,P3=0.001,respectively),the differences between Group IRLA and Group FA,Group IRLA and Group IRLA +FA in VAS II and VAS III were statistically significant. CONCLUSION: The intravenous flurbiprofen axetil was found to be more effective than intrarectal lidocaine gel alone.


Assuntos
Anestésicos Locais , Biópsia , Bloqueio Nervoso , Manejo da Dor , Neoplasias da Próstata , Biópsia/efeitos adversos , Flurbiprofeno/análogos & derivados , Humanos , Lidocaína , Masculino , Neoplasias da Próstata/diagnóstico
19.
Beijing Da Xue Xue Bao Yi Xue Ban ; 49(4): 575-579, 2017 08 18.
Artigo em Zh | MEDLINE | ID: mdl-28816268

RESUMO

OBJECTIVE: To study the expression of transmembrane protein CMTM2 in the testis and sperm of adult males and to approach the potential function of the protein in the male reproductive system. METHODS: The expression of CMTM2 in human testis and sperm was confirmed by Western blot. Immunohistochemical staining was used for detecting CMTM2 localization in the testis tissue, TRITC-CMTM2 and FITC-Hoechst double immunofluorescence staining was performed to examine the subcellular localization of CMTM2 in the human sperm before and after acrosome reaction, that is, immunofluorescent staining was used for detecting CMTM2 localization in both the testis and sperm before and after the acrosome reaction. RESULTS: CMTM2 was presented in both human testis and sperm. In the testis, CMTM2 immunoreactive particles were observed mainly in the membrane of the different stages of spermatogenic cells. In the human sperm, its immunoreactivity was restrictively localized to the posterior head where sperm-egg fusion occurred, and the CMTM2 localization was not affected by sperm acrosome reaction. CMTM2 was widely expressed in seminiferous tubules of the human testis, mainly in the cell membranes of spermatogenic cells, which was consistent with the previous reports. The immunofluorescence performed on frozen human testis slides showed similar findings with immunohistochemistry, which gave weight to the localization of CMTM2 in the cell membranes of spermatogenic cells at different stages. TRITC-CMTM2 and FITC-Hoechst double immunofluorescence staining was performed to examine the subcellular localization of CMTM2 in the human sperm before and after acrosome reaction. CMTM2 was localized at the posterior head of sperm before and after acrosome reaction. The localization and expression of CMTM2 were not affected by sperm acrosome reaction. CONCLUSION: Expression of CMTM2 in the male reproductive system of the adult human exhibits cell- and region-specific patterns, which suggests that they may play an important role in spermatogenesis and sperm-egg fusion. The expression of CMTM2 in the male reproductive system of the adult human exhibits cell- and region-specific patterns, which suggests that they may play an important role in spermatogenesis and sperm-egg fusion. However, it still remains to be further elucidated about the definite role of CMTM2 in male reproductive system and the process of spermatogenesis. And in vitro fertilization experiments are needed to confirm the role of CMTM2 in fertilization in future.


Assuntos
Quimiocinas , Proteínas com Domínio MARVEL , Espermatogênese , Espermatozoides , Testículo , Reação Acrossômica , Adulto , Quimiocinas/metabolismo , Humanos , Proteínas com Domínio MARVEL/metabolismo , Masculino , Proteínas de Membrana , Espermatozoides/metabolismo , Testículo/metabolismo
20.
Zhonghua Bing Li Xue Za Zhi ; 46(9): 634-639, 2017 Sep 08.
Artigo em Zh | MEDLINE | ID: mdl-28910875

RESUMO

Objective: To investigate the clinicopathologic and prognostic features of Claudin-low breast cancers (CLBC). Methods: Tissue microarray sections were scored semiquantitatively for the immunohistochemical expression of claudin-1, -3, -4, -7 and -8 in 233 cases of invasive breast cancers collected from Qingdao Central Hospital from January 2010 to December 2011. Results: The expression rate of Claudin-3 (72/212, 33.9%) and -4 (56/212, 45.2%) was most similar, and Claudin-4 showed the highest expression. Twenty one cases (21/212, 9.0%) were diagnosed as CLBC, with triple-negative breast cancer (TNBC) accounted for the highest proportion (11/21, 52.4%). Among the CLBC cases, the invasive carcinoma no special type (66.7%, 14/21) and metaplastic carcinoma (14.3%, 3/21) were mostly seen, while metaplastic squamous carcinoma did not show Claudin-low pattern. Compared to the non CLBC in this cohort, CLBC had higher proportion of histologic grade 3 and tumors larger than 2 cm, and the proportions were slightly lower than TNBC. Patients with CLBC had lower 5 year disease-free(P>0.05) and overall survival rates(P=0.018). Conclusion: CLBC shows distinct clinicopathologic and prognostic features comparing to other subtypes, and is associated with poor prognosis.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Claudinas/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Claudina-3/metabolismo , Claudina-4/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Prognóstico , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/mortalidade , Neoplasias de Mama Triplo Negativas/patologia
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