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1.
J Physiol ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38837412

RESUMO

In mammals, odour information within the olfactory bulb (OB) is processed by complex neural circuits before being ultimately represented in the action potential activity of mitral/tufted cells (M/Ts). Cholecystokinin-expressing (CCK+) superficial tufted cells (sTCs) are a subset of tufted cells that potentially contribute to olfactory processing in the OB by orchestrating M/T activity. However, the exact role of CCK+ sTCs in modulating odour processing and olfactory function in vivo is largely unknown. Here, we demonstrate that manipulating CCK+ sTCs can generate perception and induce place avoidance. Optogenetic activation/inactivation of CCK+ sTCs exerted strong but differing effects on spontaneous and odour-evoked M/T firing. Furthermore, inactivation of CCK+ sTCs disrupted M/T odour encoding and impaired olfactory detection and odour discrimination. These results establish the role of CCK+ sTCs in odour representation and olfactory behaviours. KEY POINTS: Mice could perceive the activity of CCK+ sTCs and show place avoidance to CCK+ sTC inactivation. Optical activation of CCK+ sTCs increased the percentage of cells with odour response but reduced the odour-evoked response in M/Ts in awake mice. Optical inactivation of CCK+ sTCs greatly decreased spontaneous firing and odour-evoked response in M/Ts. Inactivation of CCK+ sTCs impairs the odour decoding performance of M/Ts and disrupts odour detection and discrimination behaviours in mice. These results indicate that CCK+ sTCs participate in modulating the odour representation and maintaining normal olfactory-related behaviours.

2.
Nano Lett ; 23(20): 9179-9186, 2023 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-37831892

RESUMO

Adhesion G protein-coupled receptors (aGPCRs) have extracellular regions (ECRs) containing GPCR autoproteolysis-inducing (GAIN) domains. The GAIN domain enables the ECR to self-cleave into N- and C-terminal fragments. However, the impact of force on the GAIN domain's conformation, critical for mechanosensitive aGPCR activation, remains unclear. Our study investigated the mechanical stability of GAIN domains in three aGPCRs (B, G, and L subfamilies) at a loading rate of 1 pN/s. We discovered that forces of a few piconewtons can destabilize the GAIN domains. In autocleaved aGPCRs ADGRG1/GPR56 and ADGRL1/LPHN1, these forces cause the GAIN domain detachment from the membrane-proximal Stachel sequence, preceded by partial unfolding. In noncleavable aGPCR ADGRB3/BAI3 and cleavage-deficient mutant ADGRG1/GPR56-T383G, complex mechanical unfolding of the GAIN domain occurs. Additionally, GAIN domain detachment happens during cell migration. Our findings support the mechanical activation hypothesis of aGPCRs, emphasizing the sensitivity of the GAIN domain structure and detachment to physiological force ranges.


Assuntos
Receptores Acoplados a Proteínas G , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/química , Modelos Moleculares , Adesão Celular
3.
Biophys J ; 122(19): 3860-3868, 2023 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-37563833

RESUMO

Single-molecule manipulation technologies have proven to be powerful tools for studying the molecular mechanisms and physical principles underlying many essential biological processes. However, achieving wide-range temperature control has been challenging due to thermal drift that undermines the stability of the instrument. This limitation has made it difficult to study biomolecules from thermophiles at their physiologically relevant temperatures and has also hindered the convenient measurement of temperature-sensitive biomolecular interactions and the fundamental thermodynamic properties of biomolecules. In this work, we present a novel design of magnetic tweezers that uses a reflective coverslip and dry objective lens to insulate the heat conductance between the sample and the objective lens, enabling stable temperature changes from ambient up to 70°C during experiments without significant thermal drift of the instrument. The performance of the technology is demonstrated through the quantification of the free energy change of a DNA hairpin over a temperature range of 22°C-72°C, from which the entropy and enthalpy changes are determined.


Assuntos
Temperatura Alta , Fenômenos Magnéticos , Temperatura , Termodinâmica , Entropia
4.
Eur J Nucl Med Mol Imaging ; 48(8): 2586-2598, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33420610

RESUMO

PURPOSE: This study aimed to establish an effective nomogram to predict primary distant metastasis (DM) in patients with nasopharyngeal carcinoma (NPC) to guide the application of PET/CT. METHODS: In total, 3591 patients with pathologically confirmed NPC were consecutively enrolled. The nomogram was constructed based on 1922 patients treated between 2007 and 2014. Multivariate logistical regression was applied to identify the independent risk factors of DM. The predictive value of the nomogram was evaluated using the concordance index (C-index), calibration curve, probability density functions (PDFs), and clinical utility curve (CUC). The results were validated in 1669 patients enrolled from 2015 to 2016. Net reclassification improvement (NRI) was applied to compare performances of the nomogram with other clinical factors. The best cut-off value of the nomogram chosen for clinical application was analyzed. RESULTS: A total of 355 patients showed primary DM among 3591 patients, yielding an incidence rate of 9.9%. Sex, N stage, EBV DNA level, lactate dehydrogenase level, and hemoglobin level were independent predictive factors for primary DM. C-indices in the training and validation cohort were 0.796 (95% CI, 0.76-0.83) and 0.779 (95% CI, 0.74-0.81), respectively. The NRI indices demonstrated that this model had better predictive performance than plasma EBV DNA level and N stage. We advocate for a threshold probability of 3.5% for guiding the application of PET/CT depending on the clinical utility analyses. CONCLUSION: This nomogram is a useful tool to predict primary DM of NPC and guide the clinical application of PET/CT individually at the initial staging.


Assuntos
Neoplasias Nasofaríngeas , Nomogramas , Fluordesoxiglucose F18 , Humanos , Carcinoma Nasofaríngeo/diagnóstico por imagem , Neoplasias Nasofaríngeas/diagnóstico por imagem , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Prognóstico
5.
BMC Cancer ; 21(1): 1320, 2021 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-34886807

RESUMO

BACKGROUND: To evaluate the prognostic value of the apparent diffusion coefficient (ADC) derived from diffusion-weighted magnetic resonance imaging (MRI) and monitor the early treatment response to induction chemotherapy (IC) with plasma EBV DNA in locoregionally advanced nasopharyngeal carcinoma (LA-NPC). RESULTS: A total of 307 stage III-IVb NPC patients were prospectively enrolled. All patients underwent MRI examinations to calculate ADC and plasma EBV DNA measurements pretreatment and post-IC. The participants' ADC value of 92.5% (284/307) increased post-IC. A higher percent change in ADC value (ΔADC%high group) post-IC was associated with a higher 5-year OS rate (90.7% vs 74.9%, p < 0.001) than those in the ΔADC%low group. Interestingly, ΔADC% was closely related to the response measured by RECIST 1.1 (p < 0.001) and plasma EBV DNA level (p = 0.037). The AUC significantly increased when post-IC plasma EBV DNA was added to ΔADC% to predict treatment failure. Thus, based on ΔADC% and plasma EBV DNA, we further divided the participants into three new prognostic response phenotypes (early response, intermediate response, and no response) that correlated with disparate risks of death (p = 0.001), disease progression (p < 0.001), distant metastasis (p < 0.001), and locoregional relapse (p < 0.001). CONCLUSION: The percentage change in ADC post-IC is indicative of treatment response and clinical outcome. ΔADC% and plasma EBV DNA-based response phenotypes may provide potential utility for early termination of treatment and allow guiding risk-adapted therapeutic strategies for LA-NPC.


Assuntos
DNA Viral/sangue , Herpesvirus Humano 4/genética , Quimioterapia de Indução , Carcinoma Nasofaríngeo , Adolescente , Adulto , Idoso , Imagem de Difusão por Ressonância Magnética , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/diagnóstico por imagem , Carcinoma Nasofaríngeo/tratamento farmacológico , Carcinoma Nasofaríngeo/epidemiologia , Carcinoma Nasofaríngeo/patologia , Prognóstico , Adulto Jovem
6.
Eur Radiol ; 31(7): 5222-5233, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33416977

RESUMO

OBJECTIVES: The value of using PET/CT for staging of stage I-II NPC remains unclear. Hence, we aimed to investigate the survival benefit of PET/CT for staging of early-stage NPC before radical therapy. METHODS: A total of 1003 patients with pathologically confirmed NPC of stages I-II were consecutively enrolled. Among them, 218 patients underwent both PET/CT and conventional workup ([CWU], head-and-neck MRI, chest radiograph, liver ultrasound, bone scintigraphy) before treatment. The remaining 785 patients only underwent CWU. The standard of truth (SOT) for lymph node metastasis was defined by the change of size according to follow-up MRI. The diagnostic efficacies were compared in 218 patients who underwent both PET/CT and CWU. After covariate adjustment using propensity scoring, a cohort of 872 patients (218 with and 654 without pre-treatment PET/CT) was included. The primary outcome was overall survival based on intention to treat. RESULTS: Retropharyngeal lymph nodes were metastatic based on follow-up MRI in 79 cases. PET/CT was significantly less sensitive than MRI in detecting retropharyngeal lymph node lesions (72.2% [62.3-82.1] vs. 91.1% [84.8-97.4], p = 0.004). Neck lymph nodes were metastatic in 89 cases and PET/CT was more sensitive than MRI (96.6% [92.8-100.0] vs. 76.4% [67.6-85.2], p < 0.001). In the survival analyses, there was no association between pre-treatment PET/CT use and improved overall survival, progression-free survival, local relapse-free survival, regional relapse-free survival, and distant metastasis-free survival. CONCLUSIONS: This study showed PET/CT is of little value for staging of stage I-II NPC patients at initial imaging. KEY POINTS: • PET/CT was more sensitive than MRI in detecting neck lymph node lesions whereas it was significantly less sensitive than MRI in detecting retropharyngeal lymph node lesions. • No association existed between pre-treatment PET/CT use and improved survival in stage I-II NPC patients.


Assuntos
Neoplasias Nasofaríngeas , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Estudos de Casos e Controles , Fluordesoxiglucose F18 , Humanos , Linfonodos/patologia , Carcinoma Nasofaríngeo/diagnóstico por imagem , Neoplasias Nasofaríngeas/diagnóstico por imagem , Neoplasias Nasofaríngeas/patologia , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Tomografia Computadorizada por Raios X
7.
J Biol Chem ; 294(15): 5890-5895, 2019 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-30787104

RESUMO

The G-rich Pu39 region of the P1 promoter of the oncogene BCL-2, an apoptosis regulator, can fold into multiple G-quadruplex (G4) structures. Bcl2-2345 and Bcl2-1245 are two major G4 species forming with high thermal stability and distinct topologies in the Pu39 region, but their folding/unfolding kinetics have not yet been investigated. Here, we used magnetic tweezers to measure the mechanical stability and the folding/unfolding kinetics of the Bcl2-2345 and Bcl2-1245 G4 structures. We report that the hybrid-stranded Bcl2-2345 G4 had a lower mechanical stability than the parallel-stranded Bcl2-1245 G4. We observed that the Bcl2-2345 G4 is a kinetically favored structure, whereas the Bcl2-1245 G4, with a slow unfolding rate, may function as a kinetic barrier for transcription. We also determined that in addition to the Bcl2-2345 and Bcl2-1245 G4s, other stable DNA secondary structures, such as a hybrid-stranded Bcl2-1234 G4, can also form in the Pu39 sequence. The characterization of the folding/unfolding kinetics of specific G4s reported here sheds light on the participation of G4s during gene transcription and provides information for designing G4-targeting small molecules that could modulate BCL-2 gene expression.


Assuntos
DNA/química , Quadruplex G , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas , Fatores de Transcrição , Proteína 3 do Linfoma de Células B , DNA/metabolismo , Regulação da Expressão Gênica , Humanos , Cinética
8.
BMC Cancer ; 20(1): 89, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32013967

RESUMO

BACKGROUND: We compared the efficacy and toxicity of three IC regimens (TPF: taxanes, cisplatin, and 5-fluorouracil; TP: taxanes and cisplatin; and PF: cisplatin and 5-fluorouracil) followed by CCRT in locoregionally advanced NPC. METHODS: The retrospective study involved 1354 patients with newly diagnosed stage III-IVA NPC treated with IC and CCRT. The median follow-up time in our cohort was 50 months. Based on EBV DNA level, all the patients with stage IV were divided into low- (pre-EBV DNA < 1500 copies) and high-risk group (pre-EBV DNA ≥ 1500 copies). Progression free survival (PFS), overall survival (OS), locoregional relapse free survival (LRFS), distant metastasis free survival (DMFS) and grade 3-4 toxicities were compared among different IC regimens. The survival rates were compared using log-rank test and a Cox proportional hazards model was used to perform multivariate analyses. RESULTS: A multivariate analysis revealed TPF to be more effective than TP. Among stage III patients, no significant difference in clinical outcome between the different IC regimens was showed, while TPF was associated with significantly better survival conditions in the stage IV patients. A further subgroup analysis revealed that only patients with pre-EBV DNA ≥ 1500 copies could benefit from the application of TPF among stage IV NPC. In terms of acute toxicities, PF was associated with fewer grade 3/4 acute toxicities. CONCLUSIONS: In low-risk NPC patients, PF-based IC showed similar efficacy as TPF and TP but was associated with fewer grade 3/4 acute toxicities. In high-risk patients, however, the TPF regimen was superior to PF and TP, although grade 3/4 toxicities were more common with the TPF regimen.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Herpesvirus Humano 4/genética , Carcinoma Nasofaríngeo/tratamento farmacológico , Neoplasias Nasofaríngeas/tratamento farmacológico , Adolescente , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Criança , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , DNA Viral/genética , Intervalo Livre de Doença , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Carcinoma Nasofaríngeo/virologia , Neoplasias Nasofaríngeas/virologia , Estudos Retrospectivos , Taxoides/administração & dosagem , Taxoides/efeitos adversos , Resultado do Tratamento , Adulto Jovem
9.
Epilepsia ; 61(2): e7-e12, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31883345

RESUMO

Seizure prediction is feasible, but greater accuracy is needed to make seizure prediction clinically viable across a large group of patients. Recent work crowdsourced state-of-the-art prediction algorithms in a worldwide competition, yielding improvements in seizure prediction performance for patients whose seizures were previously found hard to anticipate. The aim of the current analysis was to explore potential performance improvements using an ensemble of the top competition algorithms. The results suggest that minor increments in performance may be possible; however, the outcomes of statistical testing limit the confidence in these increments. Our results suggest that for the specific algorithms, evaluation framework, and data considered here, incremental improvements are achievable but there may be upper bounds on machine learning-based seizure prediction performance for some patients whose seizures are challenging to predict. Other more tailored approaches that, for example, take into account a deeper understanding of preictal mechanisms, patient-specific sleep-wake rhythms, or novel measurement approaches, may still offer further gains for these types of patients.


Assuntos
Algoritmos , Eletrocorticografia/métodos , Convulsões/diagnóstico , Crowdsourcing , Epilepsia Resistente a Medicamentos/diagnóstico , Eletroencefalografia , Epilepsias Parciais/diagnóstico , Estudos de Viabilidade , Feminino , Humanos , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Sono , Adulto Jovem
10.
Proc Natl Acad Sci U S A ; 114(47): 12560-12565, 2017 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-29109287

RESUMO

Nucleoid-associated proteins (NAPs) facilitate chromosome organization in bacteria, but the precise mechanism remains elusive. H-NS is a NAP that also plays a major role in silencing pathogen genes. We used genetics, single-particle tracking in live cells, superresolution microscopy, atomic force microscopy, and molecular dynamics simulations to examine H-NS/DNA interactions in single cells. We discovered a role for the unstructured linker region connecting the N-terminal oligomerization and C-terminal DNA binding domains. In the present work we demonstrate that linker amino acids promote engagement with DNA. In the absence of linker contacts, H-NS binding is significantly reduced, although no change in chromosome compaction is observed. H-NS is not localized to two distinct foci; rather, it is scattered all around the nucleoid. The linker makes DNA contacts that are required for gene silencing, while chromosome compaction does not appear to be an important H-NS function.


Assuntos
DNA/química , Proteínas de Escherichia coli/química , Escherichia coli/genética , Proteínas de Fímbrias/química , Regulação Bacteriana da Expressão Gênica , Inativação Gênica , Sequência de Aminoácidos , Sítios de Ligação , DNA/genética , DNA/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Proteínas de Fímbrias/genética , Proteínas de Fímbrias/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Análise de Célula Única/métodos , Eletricidade Estática
11.
BMC Cancer ; 19(1): 908, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31511059

RESUMO

BACKGROUND: This study aimed to evaluate the prognostic value of maximal standard uptake values (SUVmax) of 18F-fluoro-2-deoxy-D-glucose positron emission tomography (PET) comparing with Epstein-Barr virus (EBV) DNA levels in de novo metastatic nasopharyngeal carcinoma (NPC) patients. METHODS: From December 2006 to December 2016, 253 de novo metastatic NPC patients assessed by PET/ computed tomography were involved in current study. SUVmax-T, SUVmax-N, and SUVmax-M referred to the SUVmax at the primary tumor, cervical lymph nodes, and metastatic lesions respectively. Overall survival (OS) was the primary endpoint. RESULT: Patients who died during the follow-up had significantly higher SUVmax-N, SUVmax-M, and EBV DNA level than those in the patients who were alive. SUVmax-N and SUVmax-M were positively correlated with EBV DNA level. The cut-off values of SUVmax-T, SUVmax-N, SUVmax-M, and EBV DNA were 17.0, 12.7, and 6.9, and 13,800 copies/mL respectively, which were determined by receiver operating characteristic (ROC) curve analysis. Patients with elevated SUVmax-N, SUVmax-M, and EBV DNA levels had a lower 3-year OS rate. In multivariate analysis, the independent prognostic factors of OS included EBV DNA, metastatic site, and locoregional radiotherapy application, while SUVmax was not an independent prognostic factor. CONCLUSION: In de novo metastatic NPC patients, higher SUVmax-N and SUVmax-M were associated with worse prognosis. However, the predictive ability of SUVmax-N and SUVmax-M was poorer than that of EBV DNA.


Assuntos
Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/virologia , Fluordesoxiglucose F18 , Herpesvirus Humano 4/genética , Carcinoma Nasofaríngeo/diagnóstico , Carcinoma Nasofaríngeo/etiologia , Tomografia por Emissão de Pósitrons , Adulto , Idoso , DNA Viral , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/mortalidade , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias Nasofaríngeas/etiologia , Neoplasias Nasofaríngeas/mortalidade , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Prognóstico , Curva ROC
12.
BMC Cancer ; 19(1): 92, 2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30665378

RESUMO

BACKGROUND: To evaluate the clinical outcome in patients with de novo metastatic nasopharyngeal carcinoma (NPC) treated or not treated with locoregional radiotherapy (LRRT) based on plasma Epstein-Barr virus (EBV) DNA level and tumor response after palliative chemotherapy (PCT). METHODS: From 2007 to 2016, 502 patients with de novo metastatic NPC were included in this study. All patients were treated with PCT and 315 patients received LRRT. Our primary study endpoint was overall survival (OS). RESULTS: EBV DNA was detected in 461 patients (91.8%) before treatment but was undetectable in 249 patients (49.6%) after PCT. Three hundred and seventeen patients (63.1%) achieved satisfactory response (complete response or partial response) to PCT. Both the post-PCT EBV DNA level and tumor response were independent prognostic factors. Among low-risk patients (patients with undetectable EBV DNA and satisfactory tumor response after PCT), the 3-year OS rate was 80.4% in LRRT-treated patients and 45.3% in patients not treated with LRRT (P < 0.001). Multivariate analyses demonstrated that LRRT was an independent prognostic factor of OS in the low-risk patients (P < 0.001). However, among the high-risk patients (patients with detectable EBV DNA and/or unsatisfactory response after PCT), no statistically significant survival differences were observed between the LRRT and non-LRRT groups. CONCLUSIONS: EBV DNA level and tumor response after PCT both correlate with the prognosis of de novo metastatic NPC. In such cases, LRRT may benefit the patients with undetectable EBV DNA levels and satisfactory tumor response after PCT.


Assuntos
Infecções por Vírus Epstein-Barr/terapia , Carcinoma Nasofaríngeo/terapia , Neoplasias Nasofaríngeas/terapia , Cuidados Paliativos/métodos , Adulto , Quimiorradioterapia/métodos , DNA Viral/sangue , Infecções por Vírus Epstein-Barr/sangue , Infecções por Vírus Epstein-Barr/virologia , Feminino , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/sangue , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/sangue , Neoplasias Nasofaríngeas/patologia , Metástase Neoplásica , Estudos Retrospectivos , Resultado do Tratamento
13.
J Natl Compr Canc Netw ; 17(6): 703-710, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-31200353

RESUMO

BACKGROUND: The goal of this study was to explore the value of adding neoadjuvant chemotherapy (NACT) or adjuvant chemotherapy (ACT) to concurrent chemoradiotherapy (CCRT) in patients with nasopharyngeal carcinoma (NPC) with different risks of treatment failure. PATIENTS AND METHODS: A total of 2,263 eligible patients with stage III-IVb NPC treated with CCRT ± NACT or ACT were included in this retrospective study. Distant metastasis-free survival (DMFS), overall survival, and progression-free survival were calculated using the Kaplan-Meier method and differences were compared using the log-rank test. RESULTS: Patients in the low-risk group (stage N0-1 disease and Epstein-Barr virus [EBV] DNA <4,000 copies/mL) who received NACT followed by CCRT achieved significantly better 5-year DMFS than those treated with CCRT alone (96.2% vs 91.3%; P= .008). Multivariate analyses also demonstrated that additional NACT was the only independent prognostic factor for DMFS (hazard ratio, 0.42; 95% CI, 0.22-0.80; P=.009). In both the intermediate-risk group (stage N0-1 disease and EBV DNA ≥4,000 copies/mL and stage N2-3 disease and EBV DNA <4,000 copies/mL) and the high-risk group (stage N2-3 disease and EBV DNA ≥4,000 copies/mL), comparison of NACT or ACT + CCRT versus CCRT alone indicated no significantly better survival for all end points. CONCLUSIONS: The addition of NACT to CCRT could reduce distant failure in patients with low risk of treatment failure.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Infecções por Vírus Epstein-Barr/terapia , Herpesvirus Humano 4/isolamento & purificação , Carcinoma Nasofaríngeo/terapia , Neoplasias Nasofaríngeas/terapia , Terapia Neoadjuvante/métodos , Adolescente , Adulto , Idoso , Quimiorradioterapia/métodos , DNA Viral/sangue , DNA Viral/isolamento & purificação , Intervalo Livre de Doença , Infecções por Vírus Epstein-Barr/mortalidade , Infecções por Vírus Epstein-Barr/patologia , Infecções por Vírus Epstein-Barr/virologia , Feminino , Herpesvirus Humano 4/genética , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/mortalidade , Carcinoma Nasofaríngeo/patologia , Carcinoma Nasofaríngeo/virologia , Neoplasias Nasofaríngeas/mortalidade , Neoplasias Nasofaríngeas/patologia , Neoplasias Nasofaríngeas/virologia , Estadiamento de Neoplasias , Intervalo Livre de Progressão , Estudos Retrospectivos , Adulto Jovem
14.
Brain ; 141(9): 2619-2630, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30101347

RESUMO

Accurate seizure prediction will transform epilepsy management by offering warnings to patients or triggering interventions. However, state-of-the-art algorithm design relies on accessing adequate long-term data. Crowd-sourcing ecosystems leverage quality data to enable cost-effective, rapid development of predictive algorithms. A crowd-sourcing ecosystem for seizure prediction is presented involving an international competition, a follow-up held-out data evaluation, and an online platform, Epilepsyecosystem.org, for yielding further improvements in prediction performance. Crowd-sourced algorithms were obtained via the 'Melbourne-University AES-MathWorks-NIH Seizure Prediction Challenge' conducted at kaggle.com. Long-term continuous intracranial electroencephalography (iEEG) data (442 days of recordings and 211 lead seizures per patient) from prediction-resistant patients who had the lowest seizure prediction performances from the NeuroVista Seizure Advisory System clinical trial were analysed. Contestants (646 individuals in 478 teams) from around the world developed algorithms to distinguish between 10-min inter-seizure versus pre-seizure data clips. Over 10 000 algorithms were submitted. The top algorithms as determined by using the contest data were evaluated on a much larger held-out dataset. The data and top algorithms are available online for further investigation and development. The top performing contest entry scored 0.81 area under the classification curve. The performance reduced by only 6.7% on held-out data. Many other teams also showed high prediction reproducibility. Pseudo-prospective evaluation demonstrated that many algorithms, when used alone or weighted by circadian information, performed better than the benchmarks, including an average increase in sensitivity of 1.9 times the original clinical trial sensitivity for matched time in warning. These results indicate that clinically-relevant seizure prediction is possible in a wider range of patients than previously thought possible. Moreover, different algorithms performed best for different patients, supporting the use of patient-specific algorithms and long-term monitoring. The crowd-sourcing ecosystem for seizure prediction will enable further worldwide community study of the data to yield greater improvements in prediction performance by way of competition, collaboration and synergism.10.1093/brain/awy210_video1awy210media15817489051001.


Assuntos
Epilepsia/fisiopatologia , Previsões/métodos , Convulsões/fisiopatologia , Adulto , Algoritmos , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Crowdsourcing/métodos , Eletroencefalografia/métodos , Feminino , Humanos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes
15.
Nucleic Acids Res ; 45(17): 10032-10041, 2017 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-28973442

RESUMO

The interaction between the single-stranded DNA and the homologous duplex DNA is essential for DNA homologous repair. Here, we report that parallel triplex structure can form spontaneously between a mechanically extended ssDNA and a homologous dsDNA in protein-free condition. The triplex has a contour length close to that of a B-form DNA duplex and remains stable after force is released. The binding energy between the ssDNA and the homologous dsDNA in the triplex is estimated to be comparable to the basepairing energy in a B-form dsDNA. As ssDNA is in a similar extended conformation within recombinase-coated nucleoprotein filaments, we propose that the parallel triplex may form and serve as an intermediate during recombinase-catalyzed homologous joint formation.


Assuntos
Reparo do DNA , DNA de Forma B/química , DNA de Cadeia Simples/química , DNA/química , Conformação de Ácido Nucleico , Humanos , Soluções , Estresse Mecânico
16.
Lancet Oncol ; 19(4): 461-473, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29501366

RESUMO

BACKGROUND: Cisplatin-based concurrent chemoradiotherapy is currently considered to be the standard treatment regimen for patients with advanced nasopharyngeal carcinoma, but has well known side-effects such as gastrointestinal reactions, nephrotoxicity, and ototoxicity. Nedaplatin was developed to decrease the toxic effects induced by cisplatin, and in this trial we assessed whether a nedaplatin-based concurrent chemoradiotherapy regimen was non-inferior to a cisplatin-based regimen in patients with locoregional, stage II-IVB nasopharyngeal carcinoma. METHODS: We did an open-label, non-inferiority, phase 3, randomised, controlled trial at two centres in China. Patients aged 18-65 years with non-keratinising stage II-IVB (T1-4N1-3 or T3-4N0) nasopharyngeal carcinoma, a Karnofsky score of at least 70, and adequate haematological, renal, and hepatic function were randomly assigned (1:1) to receive intravenously either nedaplatin 100 mg/m2 or cisplatin 100 mg/m2 on days 1, 22, and 43 for three cycles concurrently with intensity-modulated radiotherapy. Randomisation was done manually using a computer-generated random number code and patients were stratified by treatment centre and clinical stage. Patients and clinicians were not masked to treatment allocation. The primary endpoint was progression-free survival at 2 years; non-inferiority was shown if the upper limit of the 95% CI for the difference in 2-year progression-free survival between the two groups did not exceed 10%. Analyses were by both intention to treat and per protocol, including all patients who received at least one complete cycle of chemotherapy. This trial is registered with ClinicalTrials.gov, number NCT01540136, and is currently in follow-up. FINDINGS: Between Jan 16, 2012, and July 16, 2014, we randomly assigned 402 patients to nedaplatin-based (n=201) or cisplatin-based (n=201) concurrent chemoradiotherapy. In the intention-to-treat population, 2-year progression-free survival was 89·9% (95% CI 85·8-94·0) in the cisplatin group and 88·0% (83·5-94·5) in the nedaplatin group, with a difference of 1·9% (95% CI -4·2 to 8·0; pnon-inferiority=0·0048). In the per-protocol analysis (cisplatin group, n=197; nedaplatin group, n=196), 2-year progression-free survival was 89·7% (95% CI 85·4-94·0) in the cisplatin group and 88·7% (84·2-94·5) in the nedaplatin group, with a difference of 1·0% (95% CI -5·2 to 7·0; pnon-inferiority=0·0020). A significantly higher frequency of grade 3 or 4 vomiting (35 [18%] of 198 in the cisplatin group vs 12 [6%] of 200 in the nedaplatin group, p<0·0001), nausea (18 [9%] vs four [2%], p=0·0021), and anorexia (53 [27%] vs 26 [13%], p=0·00070) was observed in the cisplatin group compared with the nedaplatin group. 11 (6%) patients in the nedaplatin group had grade 3 or 4 thrombocytopenia compared with four (2%) in the cisplatin group (p=0·065). Patients in the cisplatin group had a higher frequency of any grade or grade 3 or 4 late auditory or hearing toxicities than did patients in the nedaplatin group (grade 3 or 4: three [2%] in the nedaplatin group vs 11 [6%] in the cisplatin group, p=0·030). No patients died from treatment-related causes. INTERPRETATION: Our findings show that nedaplatin-based concurrent chemoradiotherapy represents an alternative doublet treatment strategy to cisplatin-based concurrent chemoradiotherapy for patients with locoregional, advanced nasopharyngeal carcinoma. Further investigations are needed to explore the potential use of this treatment as induction or adjuvant chemotherapy or in combination with other agents. FUNDING: National Key R&D Program of China, National Natural Science Foundation of China, Sun Yat-sen University Clinical Research 5010 Program, Sci-Tech Project Foundation of Guangzhou City, National Key Basic Research Program of China, Special Support Plan of Guangdong Province, Sci-Tech Project Foundation of Guangdong Province, Health & Medical Collaborative Innovation Project of Guangzhou City, National Science & Technology Pillar Program during the Twelfth Five-year Plan Period, PhD Start-up Fund of Natural Science Foundation of Guangdong Province, Cultivation Foundation for the Junior Teachers in Sun Yat-sen University, and Fundamental Research Funds for the Central Universities.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma/terapia , Quimiorradioterapia , Cisplatino/uso terapêutico , Neoplasias Nasofaríngeas/terapia , Compostos Organoplatínicos/uso terapêutico , Adolescente , Adulto , Idoso , Anorexia/induzido quimicamente , Antineoplásicos/efeitos adversos , Carcinoma/secundário , Cisplatino/efeitos adversos , Feminino , Transtornos da Audição/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/patologia , Náusea/induzido quimicamente , Compostos Organoplatínicos/efeitos adversos , Intervalo Livre de Progressão , Dosagem Radioterapêutica , Trombocitopenia/induzido quimicamente , Vômito/induzido quimicamente , Adulto Jovem
17.
BMC Cancer ; 18(1): 1297, 2018 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-30594171

RESUMO

BACKGROUND: Despite increasing use, symptomatic venous thromboembolism (VTE) associated with peripherally inserted central catheter (PICC) is a common complication in nonmetastatic nasopharyngeal carcinoma (NPC) patients. METHODS: A total of 3012 nonmetastatic NPC patients were enrolled in this retrospective study, and we applied Cox regression and log-rank tests to assess the association between PICC-VTE and survival using the propensity score method (PSM) to adjust for gender, age, radiotherapy technique, tumor stage, node stage, UICC clinical stage and pre-treatment EBV DNA. RESULTS: 217 patients developed PICC-VTE, with an incidence of 7.20%. PSM identified 213 patients in the cohort with VTE and 852 in that without. Patients who developed PICC-VTE had a shorter 5-year PFS (77.5% vs 87.6%, p < 0.001), DMFS (85.0% vs 91.2%, p < 0.001), LRRFS (93.9% vs 97.7%, p < 0.001) and OS (85.4% vs 87.6%, p < 0.001). Subgroup analyses indicated that no significant survival difference was found between PICC-related superficial venous thrombosis and deep vein thrombosis, nor did different anticoagulant treatment methods. CONCLUSIONS: PICC-VTE was associated with a worse survival outcome in nonmetastatic NPC patients. A prospective randomized clinical trial is required to verify the results.


Assuntos
Anticoagulantes/uso terapêutico , Cateterismo Periférico/efeitos adversos , Carcinoma Nasofaríngeo/mortalidade , Neoplasias Nasofaríngeas/mortalidade , Tromboembolia Venosa/epidemiologia , Adulto , Cateterismo Periférico/instrumentação , Cateteres Venosos Centrais/efeitos adversos , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/complicações , Carcinoma Nasofaríngeo/terapia , Neoplasias Nasofaríngeas/complicações , Neoplasias Nasofaríngeas/terapia , Pontuação de Propensão , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida , Taxa de Sobrevida , Tromboembolia Venosa/tratamento farmacológico , Tromboembolia Venosa/etiologia
18.
BMC Cancer ; 18(1): 1279, 2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30572856

RESUMO

BACKGROUND: We wished to evaluate the efficacy and safety of liposomal paclitaxel and docetaxel for induction chemotherapy (IC) for nasopharyngeal carcinoma (NPC). METHODS: A total of 1498 patients with newly-diagnosed NPC between 2009 and 2017 treated with IC plus concurrent chemotherapy were included in our observational study. Overall survival (OS), progression-free survival (PFS), locoregional relapse-free survival (LRFS), distant metastasis-free survival (DMFS) and grade-3-4 toxicities were compared between groups using propensity score matching (PSM). RESULTS: In total, 767 patients were eligible for this study, with 104 (13.6%) and 663 (86.4%) receiving a liposomal paclitaxel-based and docetaxel-based taxanes, cisplatin and 5-fluorouracil (TPF) regimen, respectively. PSM identified 103 patients in the liposomal-paclitaxel group and 287 patients in the docetaxel group. There was no significant difference at 3 years for OS (92.2% vs. 93.9%, P = 0.942), PFS (82.6% vs. 81.7%, P = 0.394), LRFS (94.7% vs. 93.3%, P = 0.981) or DMFS (84.6% vs. 87.4%, P = 0.371) between the two groups after PSM. Significant interactions were not observed between the effect of chemotherapy regimen and sex, age, T stage, N stage, overall stage, or Epstein-Barr virus DNA level in the subgroup multivariate analysis. The prevalence of grade-3-4 leukopenia and neutropenia in the liposomal-paclitaxel group was significantly lower than that of the docetaxel group (P < 0.05 for all). CONCLUSIONS: Compared with docetaxel, liposomal paclitaxel has identical anti-tumor efficacy, but causes fewer and milder adverse reactions in IC for NPC.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/fisiopatologia , Carcinoma Nasofaríngeo/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Neutropenia/fisiopatologia , Adolescente , Adulto , Idoso , Linhagem Celular Tumoral , Cisplatino/administração & dosagem , Cisplatino/efeitos adversos , Intervalo Livre de Doença , Docetaxel/administração & dosagem , Docetaxel/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Herpesvirus Humano 4/genética , Humanos , Lipossomos/química , Lipossomos/farmacologia , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/epidemiologia , Carcinoma Nasofaríngeo/patologia , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/patologia , Neutropenia/induzido quimicamente , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Taxoides/administração & dosagem , Taxoides/efeitos adversos
19.
Biophys J ; 111(11): 2349-2357, 2016 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-27926836

RESUMO

Unfolded protein, a disordered structure found before folding of newly synthesized protein or after protein denaturation, is a substrate for binding by many cellular factors such as heat-stable proteins, chaperones, and many small molecules. However, it is challenging to directly probe such interactions in physiological solution conditions because proteins are largely in their folded state. In this work we probed small molecule binding to mechanically unfolded polyprotein using sodium dodecyl sulfate (SDS) as an example. The effect of binding is quantified based on changes in the elasticity and refolding of the unfolded polyprotein in the presence of SDS. We show that this single-molecule mechanical detection of binding to unfolded polyprotein can serve, to our knowledge, as a novel label-free assay with a great potential to study many factors that interact with unfolded protein domains, which underlie many important biological processes.


Assuntos
Elasticidade , Desnaturação Proteica , Redobramento de Proteína , Proteínas/química , Proteínas/metabolismo , Guanidina/metabolismo , Guanidina/farmacologia , Modelos Moleculares , Desnaturação Proteica/efeitos dos fármacos , Redobramento de Proteína/efeitos dos fármacos , Dodecilsulfato de Sódio/metabolismo , Dodecilsulfato de Sódio/farmacologia , Ureia/metabolismo , Ureia/farmacologia
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