Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Eur Radiol ; 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32064562

RESUMO

INTRODUCTION: We aimed to investigate the utility of compressed sensing time-of-flight magnetic resonance angiography (CS TOF-MRA) for diagnosing intracranial and cervical arterial stenosis by using digital subtraction angiography (DSA) as the reference standard. METHODS: Thirty-seven patients with head and neck arterial stenoses who underwent CS TOF-MRA and DSA were retrospectively enrolled. The reconstructed resolution of CS TOF-MRA was 0.4 × 0.4 × 0.4 mm3. The scan time was 5 min and 2 s. The image quality of CS TOF-MRA was independently ranked by two neuroradiologists in 1031 arterial segments. The luminal stenosis grades on CS TOF-MRA and DSA were analyzed in 61 arterial segments and were compared using the Wilcoxon signed-rank test. The ability of CS TOF-MRA to predict moderate to severe stenosis or occlusion was analyzed. RESULTS: The image quality of most arterial segments (95.2%) on CS TOF-MRA was excellent. Arterial segments with low image quality were mainly the V3-4 segments of the vertebral artery. The majority of arterial stenoses (62.3%) were located in the cervical internal carotid artery. The luminal stenosis grades of CS TOF-MRA were concordant with that of DSA in 50 of 61 segments (p = 0.366). CS TOF-MRA had a sensitivity of 84.4% and a specificity of 88.5% for predicting moderate to severe stenosis. For detecting occlusion lesions, it had a sensitivity of 100% and a specificity of 94.1%. CONCLUSION: CS TOF-MRA provides adequate image quality within a reasonable acquisition time and is a reliable tool for diagnosing head and neck arterial steno-occlusive disease. KEY POINTS: • CS TOF-MRA provides a relatively large coverage (16 cm), high resolution (0.4 × 0.4 × 0.4 mm3) and good image quality of head and neck arteries within 5 min and 2 s. • The diagnostic accuracy of CS TOF-MRA in the assessment of moderate to severe stenosis and occlusion was comparable with that of DSA. • Arterial segments with low image quality were mainly the V3 and V4 segments of the vertebral artery.

2.
Diagn Interv Radiol ; 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32071025

RESUMO

PURPOSE We aimed to investigate histogram analysis of diffusion kurtosis imaging (DKI) and conventional diffusion-weighted imaging (DWI) to distinguish between deep myometrial invasion and superficial myometrial invasion in endometrial carcinoma (EC). METHODS A total of 118 pathologically confirmed EC patients with preoperative DWI were included. The data were postprocessed with a DKI (b value of 0, 700, 1400, and 2000 s/mm2) model for quantitation of apparent diffusion values (D) and apparent kurtosis coefficient values (K) for non-Gaussian distribution. The apparent diffusion coefficient (ADC) was postprocessed with a conventional DWI model (b values of 0 and 800 s/mm2). A whole-tumor analysis approach was used. Comparisons of the histogram parameters of D, K, and ADC were carried out for the deep myometrial invasion and superficial myometrial invasion subgroups. Diagnostic performance of the imaging parameters was assessed. RESULTS The Dmean, D10th, and D90th in deep myometrial invasion group were significantly lower than those in superficial invasion group (P < 0.001, P < 0.001, and P = 0.023, respectively), as well as the ADCmean, ADC10th, and ADC90th (P = 0.001, P = 0.001, and P = 0.042, respectively). The Kmean and K90th were significantly higher in deep invasion group than those in superficial myometrial invasion group (P = 0.002 and P = 0.026, respectively). The D10th, Kmean, and ADC10th had a relatively higher area under the curve (AUC) (0.72, 0.66, and 0.71, respectively) than other parameters for distinguishing deep myometrial invasion of EC. D10th showed a relatively higher AUC than ADC10th for the differentiation of lesions with deep myometrial invasion from those with superficial myometrial invasion (0.72 vs. 0.71), but the variation was not statistically significant (P = 0.35). CONCLUSION Distribution of DKI and conventional DWI parameters characterized by histogram analysis may represent an indicator for deep myometrial invasion in EC. Both DKI and DWI models showed relatively equivalent effectiveness.

3.
J Magn Reson Imaging ; 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31769565

RESUMO

BACKGROUND: Preoperative evaluation of the consistency of pituitary macroadenomas is important for neurosurgeons to prepare the surgical plan. PURPOSE: To evaluate the diagnostic performance of texture analysis (TA) of diffusion-weighted imaging (DWI) at a standard b-value (b = 1000 s/mm2 ) and a high b-value (b = 2000 s/mm2 ) for their ability to assess the tumor consistency of pituitary macroadenomas. STUDY TYPE: Retrospective. POPULATION/SUBJECTS: Fifty patients with histologically confirmed pituitary macroadenomas were classified as soft (n = 37) or hard (n = 13) types. FIELD STRENGTH/SEQUENCE: Coronal T2 -weighted imaging (T2 WI), Readout Segmentation of Long Variable Echo-trains (RESOLVE) DWI at b = 1000 s/mm2 and b = 2000 s/mm2 were acquired with 3.0T MRI. ASSESSMENT: The corresponding apparent diffusion coefficient (ADC) maps (ADC1000 and ADC2000 ) were registered to T2 WI. Regions of interest (ROIs) were manually drawn along the solid part of the tumor from the coregistered T2 WI-ADC images. The texture parameters from T2 WI, ADC1000 , and ADC2000 were acquired. STATISTICAL TESTS: The texture parameters were compared between the two types by using unpaired Student's t-test. Receiver operating characteristic (ROC) curves and logistic regression analyses were used to assess their diagnostic performance. RESULTS: Significant differences in TA parameters of ADC1000 and ADC2000 were observed between soft and hard types (P < 0.05 for all), whereas the TA of T2 WI resulted in no significant difference (P > 0.05 for all). TA of ADC2000 provided a superior diagnostic performance compared with that of ADC1000 (P = 0.038). A combination of mean value and entropy of ADC2000 yielded an AUC, a sensitivity, and a specificity of 0.911, 78.4% and 92.3%, respectively. DATA CONCLUSION: TA of ADC values were useful for assessing the tumor consistency of pituitary macroadenomas. ADC2000 may facilitate better type discrimination. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019.

4.
J Comput Assist Tomogr ; 43(6): 948-952, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31688249

RESUMO

PURPOSE: This study aimed to evaluate the image quality and degree of metal artifact reduction using the new-generation gemstone spectral imaging (GSI) and metal artifact reduction software (MARs) and to demonstrate the optimal monochromatic energy level for dual-energy cerebral computed tomography angiography (CTA) in patients with intracranial aneurysm after endovascular treatment. MATERIAL AND METHODS: A total of 20 patients with cerebral aneurysms treated with coils or clips underwent CTA using gemstone spectral computed tomography. Artifact index was calculated at each energy level with and without MARs. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated on all axial images with MARs; subjective evaluation was done by using a 4-point scale and a 3-point scale for assessing noise and vessel contrast, respectively, and compared between the monochromatic energy levels. RESULTS: The artifact index value of group GSI-MARs was significantly lower than that of group GSI at each monochromatic energy level (all, P < 0.01). Contrast-to-noise ratio and SNR of the parent arteries decreased as the energy increased from 40 to 140 keV in group GSI-MARs (all, P < 0.01). Signal-to-noise ratio and CNR between each 2 adjacent monochromatic energy level showed significant difference (all, P < 0.01). Subjective evaluation showed that a monochromatic energy level between 40 and 70 keV provided the optimal image quality. CONCLUSION: Gemstone spectral imaging with MARs could reduce metal artifacts and improve the image quality of cerebral CTA after coil or clip treatment. The new generation of GSI could provide better CNR and SNR at lower energy level, and the best image quality was obtained at energy level 40 to 70 keV for GSI-MARs.


Assuntos
Procedimentos Endovasculares/métodos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Intensificação de Imagem Radiográfica/métodos , Adulto , Idoso , Artefatos , Angiografia por Tomografia Computadorizada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Estudos Retrospectivos , Razão Sinal-Ruído , Software
5.
J Clin Neurosci ; 64: 145-149, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30929959

RESUMO

Our objective was to assess the impact of hs-cTnT elevation on functional outcome and mortality in AIS patients with large vessel occlusion (LVO) in the anterior circulation 3 months after ET and explore factors affecting hs-cTnT elevation. A total of 143 consecutive AIS patients with large vessel occlusion (LVO) in the anterior circulation following ET in a single stroke center were enrolled between January 2015 and November 2017. Hs-cTnT was quantitated on admission. Demographic characteristics, clinical data, functional outcome and all-cause mortality were compared between patients with elevated hs-cTnT levels (>14 ng/L) and those with normal hs-cTnT levels (≤14 ng/L). 58/143(40.6%) patients showed elevated hs-cTnT levels before ET. Factors independently associated with hs-cTnT elevation were admission NIHSS score (OR = 1.08, 95% CI 1.01-1.16, p = 0.032), coronary heart disease (OR = 4.89, 95% CI 1.82-13.11, p = 0.002) and congestive heart failure (OR = 4.10, 95% CI 1.07-15.68, p = 0.039). In the univariate analysis, patients with elevated hs-cTnT levels were at significantly higher risk of 3-month poor outcome (p = 0.029) and mortality (p < 0.001) than those with normal hs-cTnT levels. After multivariable analysis, hs-cTnT elevation remained an independent predictor of 3-month mortality (OR = 4.49, 95% CI 1.68-11.98, p = 0.003). In this cohort of AIS patients with LVO in the anterior circulation undergoing ET, hs-cTnT elevation is an independent predictor of 3-month mortality. Admission NIHSS score, coronary heart disease and congestive heart failure are independently associated with elevated hs-cTnT levels.


Assuntos
Biomarcadores/sangue , Acidente Vascular Cerebral/cirurgia , Troponina T/sangue , Idoso , Isquemia Encefálica/sangue , Isquemia Encefálica/mortalidade , Isquemia Encefálica/cirurgia , Estudos de Coortes , Procedimentos Endovasculares/métodos , Procedimentos Endovasculares/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/mortalidade , Trombectomia/métodos , Trombectomia/mortalidade
6.
Eur Radiol ; 29(9): 4922-4929, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30762114

RESUMO

OBJECTIVES: To compare collateral status on single-phase CT angiography (sCTA) and multiphase CT angiography (mCTA) and their ability to predict a target mismatch on CT perfusion (CTP) and clinical outcome in patients with acute ischemic stroke (AIS). METHODS: Seventy-three AIS patients with stroke onset between 5 and 15 h or with unclear onset time and occlusions in the M1/M2 segment of the middle cerebral artery and/or intracranial internal carotid artery underwent head non-contrast CT and CTP. Simulated sCTA and mCTA were reconstructed from CTP data and were compared for collaterals assessment. The ability to predict target mismatch on CTP (an ischemic core < 70 ml, a mismatch ratio ≥ 1.8, and an absolute difference ≥ 15 ml) and 90-day modified Rankin Scale (mRS) score of 0-2 was compared between sCTA and mCTA by using receiver operating curve analysis. RESULTS: sCTA underestimated the collateral status when compared with mCTA (p < 0.01). The ability of mCTA to predict target mismatch (AUC = 0.902, 95% confidence interval [CI] 0.809, 0.959) and clinical outcome (AUC = 0.771; 95% CI, 0.655, 0.864) was better than that of sCTA (p < 0.05 overall). A mCTA collateral score of > 3 best identified the target mismatch (sensitivity, 78.4%; specificity, 90.9%) and predicted 90-day mRS score of 0-2 (sensitivity, 84.8%; specificity, 69.4%). CONCLUSIONS: The collaterals were better estimated by mCTA compared with sCTA. A mCTA collateral score of > 3 optimized the prediction of a target mismatch on CTP and a good clinical outcome in patients with AIS. KEY POINTS: • Collateral circulation is a key determinant of ischemic core and penumbra. Better collaterals are associated with smaller ischemic core volumes and larger mismatch ratios on CT perfusion. • The collaterals can be better estimated by multiphase CTA compared with single-phase CTA. • A collateral score of > 3 on multiphase CTA best identifies patients with target mismatch on CT perfusion and predicts 90-day mRS score of 0-2.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/fisiopatologia , Circulação Colateral , Angiografia por Tomografia Computadorizada/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/fisiopatologia , Idoso , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/fisiopatologia , Angiografia Cerebral , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Artéria Cerebral Média/fisiopatologia , Imagem de Perfusão , Sensibilidade e Especificidade
7.
Cancer Lett ; 444: 162-174, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30583071

RESUMO

Our phosphoproteomics identified that phosphorylation of EphA2 at serine 897 (pS897-EphA2) was significantly upregulated in the high metastatic nasopharyngeal carcinoma (NPC) cells relative to non-metastatic NPC cells. However, the role and underlying mechanism of pS897-EphA2 in cancer metastasis and stem properties maintenance remain poorly understood. In this study, we established NPC cell lines with stable expression of exogenous EphA2 and EphA2-S897A using endogenous EphA2 knockdown cells, and observed that pS897-EphA2 maintained EphA2-dependent NPC cell in vitro migration and invasion, in vivo metastasis and cancer stem properties. Using phospho-kinase antibody array to identify signaling downstream of pS897-EphA2, we found that AKT/Stat3 signaling mediated pS897-EphA2-promoting NPC cell invasion, metastasis and stem properties, and Sox-2 and c-Myc were the effectors of pS897-EphA2. Immunohistochemistry showed that pS897-EphA2 was positively correlated with NPC metastasis and negatively correlated with patient overall survival. Moreover, ERK/RSK signaling controlled serum-induced pS897-EphA2 in NPC cells. Collectively, our results demonstrate that pS897-EphA2 is indispensable for EphA2-dependent NPC cell invasion, metastasis and stem properties by activating AKT/Stat3/Sox-2 and c-Myc signaling pathway, suggesting that pS897-EphA2 can serve as a therapeutic target in NPC and perhaps in other cancers.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Pulmonares/secundário , Neoplasias Nasofaríngeas/patologia , Células-Tronco Neoplásicas/patologia , Receptor EphA2/metabolismo , Animais , Apoptose , Biomarcadores Tumorais/genética , Proliferação de Células , Seguimentos , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Metástase Linfática , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/metabolismo , Invasividade Neoplásica , Células-Tronco Neoplásicas/metabolismo , Fosforilação , Prognóstico , Receptor EphA2/genética , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Acta Radiol ; 60(6): 777-787, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30244590

RESUMO

BACKGROUND: The application of conventional magnetic resonance imaging (MRI) in glioma grading is limited and non-specific. PURPOSE: To investigate the application values of MRI, texture analysis (TA) of dynamic contrast-enhanced MRI (DCE-MRI) and intratumoral susceptibility signal (ITSS) on susceptibility weighted imaging (SWI), alone and in combination, for glioma grading. MATERIAL AND METHODS: Fifty-two patients with pathologically confirmed gliomas who underwent DCE-MRI and SWI were enrolled in this retrospective study. Conventional MRIs were evaluated by the VASARI scoring system. TA of DCE-MRI-derived parameters and the degree of ITSS were compared between low-grade gliomas (LGGs) and high-grade gliomas (HGGs). The diagnostic ability of each parameter and their combination for glioma grading were analyzed. RESULTS: Significant statistical differences in VASARI features were observed between LGGs and HGGs ( P < 0.05), of which the enhancement quality had the highest area under the curve (AUC) (0.873) with 93.3% sensitivity and 80% specificity. The TA of DCE-MRI derived parameters were significantly different between LGGs and HGGs ( P < 0.05), of which the uniformity of Ktrans had the highest AUC (0.917) with 93.3% sensitivity and 90% specificity. The degree of ITSS was significantly different between LGGs and HGGs ( P < 0.001). The AUC of the ITSS was 0.925 with 93.3% sensitivity and 90% specificity. The best discriminative power was obtained from a combination of enhancement quality, Ktrans- uniformity, and ITSS, resulting in 96.7% sensitivity, 100.0% specificity, and AUC of 0.993. CONCLUSION: Combining conventional MRI, TA of DCE-MRI, and ITSS on SWI may help to improve the differentiation between LGGs and HGGs.


Assuntos
Neoplasias Encefálicas/patologia , Meios de Contraste , Glioma/patologia , Aumento da Imagem/métodos , Imagem por Ressonância Magnética/métodos , Adulto , Idoso , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Neoplasias Encefálicas/diagnóstico por imagem , Feminino , Glioma/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
9.
J Cell Physiol ; 234(2): 1354-1368, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30076722

RESUMO

In recent years, studies have shown that the secretome of bone marrow mesenchymal stromal cells (BMSCs) contains many growth factors, cytokines, and antioxidants, which may provide novel approaches to treat ischemic diseases. Furthermore, the secretome may be modulated by hypoxic preconditioning. We hypothesized that conditioned medium (CM) derived from BMSCs plays a crucial role in reducing tissue damage and improving neurological recovery after ischemic stroke and that hypoxic preconditioning of BMSCs robustly improves these activities. Rats were subjected to ischemic stroke by middle cerebral artery occlusion and then intravenously administered hypoxic CM, normoxic CM, or Dulbecco modified Eagle medium (DMEM, control). Cytokine antibody arrays and label-free quantitative proteomics analysis were used to compare the differences between hypoxic CM and normoxic CM. Injection of normoxic CM significantly reduced the infarct area and improved neurological recovery after stroke compared with administering DMEM. These outcomes may be associated with the attenuation of apoptosis and promotion of angiogenesis. Hypoxic preconditioning significantly enhanced these therapeutic effects. Fourteen proteins were significantly increased in hypoxic CM compared with normoxic CM as measured by cytokine arrays. The label-free quantitative proteomics analysis revealed 163 proteins that were differentially expressed between the two groups, including 107 upregulated proteins and 56 downregulated proteins. Collectively, our results demonstrate that hypoxic CM protected brain tissue from ischemic injury and promoted functional recovery after stroke in rats and that hypoxic CM may be the basis of a potential therapy for stroke patients.


Assuntos
Células da Medula Óssea/metabolismo , Encéfalo/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Infarto da Artéria Cerebral Média/tratamento farmacológico , Células-Tronco Mesenquimais/metabolismo , Fármacos Neuroprotetores/farmacologia , Animais , Apoptose/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Hipóxia Celular , Células Cultivadas , Meios de Cultivo Condicionados/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/fisiopatologia , Masculino , Neovascularização Fisiológica/efeitos dos fármacos , Fármacos Neuroprotetores/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Sprague-Dawley , Recuperação de Função Fisiológica
10.
ACS Appl Mater Interfaces ; 10(50): 43561-43569, 2018 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-30521308

RESUMO

The hydrogen evolution reaction activity of carbon-supported Pt catalyst is highly dependent on Pt-C interfaces. Herein, we focus on the relationships between Pt activity and N/O-functionalized hollow carbon sphere (HCS) substrate in acidic media. The electrochemical dissolution of Pt counter electrode is performed to prepare Pt nanoparticles in low loading. The N groups are beneficial for homogeneously sized Pt nanoparticles, whereas the O groups lead to aggregated nanoparticles. Moreover, the proper electronegativity of the N groups may enable capturing of protons to create proton-rich Pt-C interfaces and transfer them onto the Pt sites. The O groups may also capture protons by hydrogen bonding, but the subsequent release of protons is more difficult due to a stronger electronegativity and result in an inferior Pt activity. Consequently, the N-doped HCS with a low Pt loading (1.7 µg cm-2 and 0.05 wt %) possesses a higher intrinsic activity compared with Pt on O-doped HCS. Moreover, it outperforms the commercial 20% Pt/C with a stable operation for 12 h. This work may provide suggestions for constructing the advantageous Pt-C interfaces by proper functional groups for high catalytic efficiencies.

11.
BMC Neurol ; 18(1): 200, 2018 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-30522455

RESUMO

BACKGROUND: Elevated plasma homocysteine (Hcy) is an independent risk factor for ischemic stroke. This study aimed to evaluate the association between Hcy levels and intracranial plaque characteristics and to investigate their clinical relevance in ischemic stroke. METHODS: Ninety-four patients with intracranial atherosclerosis (ICAS) were enrolled. Plasma Hcy levels were measured. Intracranial plaque characteristics including plaque enhancement, stenosis ratio, T2 and T1 hyperintense components were assessed on high-resolution magnetic resonance imaging. Logistic regression model was constructed to analyze the association between high Hcy levels and plaque characteristics, and their synergistic effects to predict the likelihood for ischemic stroke, while adjusting for demographics and traditional atherosclerotic risk factors. RESULTS: Elevated Hcy level was associated with strong plaque enhancement independently of age, sex, serum creatinine levels and other atherosclerotic risk factors ((P < 0.001, OR 6.00, 95% confidence interval [CI] 2.28-15.74). Both strong plaque enhancement (P = 0.026, OR 5.63, 95% CI 1.23-25.81) and high Hcy level (P = 0.018, OR 6.20, 95% CI 1.36-28.26) were correlated with acute ischemic stroke. The combination of them strengthened the ability to stratify the likelihood for ischemic stroke, with an improved area under the receiver operating characteristic curve (AUC) of 0.871, significantly higher than that of strong plaque enhancement (0.755) and high Hcy level (0.715) alone (P < 0.05 for both). CONCLUSIONS: High Hcy level appears to have association with intracranial strong plaque enhancement. The combined assessment of plasma Hcy levels and plaque enhancement may improve ischemic stroke risk stratification.


Assuntos
Homocisteína/sangue , Arteriosclerose Intracraniana/complicações , Arteriosclerose Intracraniana/patologia , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/patologia , Idoso , Biomarcadores/sangue , Feminino , Humanos , Arteriosclerose Intracraniana/sangue , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Curva ROC , Fatores de Risco
12.
Cell Death Dis ; 9(12): 1154, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30459351

RESUMO

Annexin A1 (ANXA1) is dysregulated in the various tumors. However, the role and mechanism of ANXA1 in the cancers are poorly understood. In this study, we first showed a clinically positive correlation between ANXA1 and autophagy-associated protein SQSTM1 expression in nasopharyngeal carcinoma (NPC) and ANXA1-regulating SQSTM1 expression through autophagy, and further demonstrated that ANXA1 inhibited BECN1 and ATG5-dependent autophagy in the NPC cells. Using phospho-kinase antibody array to identify signaling through which ANXA1 regulated NPC cell autophagy, we found that ANXA1-suppressed autophagy was associated with PI3K/AKT signaling activation. We also showed that ANXA1 expression was significantly increased in the NPCs with metastasis relative to NPCs without metastasis and positively correlated with lymphonode and distant metastasis; high ANXA1 expression in the NPC cells promoted in vitro tumor cell migration and invasion and in vivo metastasis. Lastly, we showed that inhibition of autophagy restored the ability of tumor cell migration and invasion, epithelial-mesenchymal transition (EMT)-like alterations and in vivo metastasis in the ANXA1 knockdown NPC cells with autophagy activation; ANXA1-suppresed autophagy induced EMT-like alterations possibly by inhibiting autophagy-mediated degradation of Snail. Our data suggest that ANXA1-suppressed autophagy promotes NPC cell migration, invasion and metastasis by activating PI3K/AKT signaling pathway, highlighting that the activation of autophagy may inhibit metastasis of NPC with high ANXA1 expression.


Assuntos
Anexina A1/genética , Autofagia/genética , Carcinoma Nasofaríngeo/genética , Proteína Sequestossoma-1/genética , Proteína 5 Relacionada à Autofagia/genética , Proteína Beclina-1/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Humanos , Carcinoma Nasofaríngeo/patologia , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Metástase Neoplásica , Fosfatidilinositol 3-Quinases/genética , Proteólise , Proteínas Proto-Oncogênicas c-akt/genética , Fatores de Transcrição da Família Snail/genética
14.
Cell Death Dis ; 9(12): 1148, 2018 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-30451832

RESUMO

RACK1 is upregulated in the various types of human cancers, and considered to play a role in the development and progression of human cancer. However, the role and mechanism of RACK in the colon cancer are poorly understood. In this study, we detected RACK1 expression in 63 normal colonic mucosa, 60 colonic inflammatory polyps, 60 colonic adenomas, 180 colon adenocarcinomas, and 40 lymph node metastases by immunohistochemistry, and observed that RACK1 expression was progressively elevated in the carcinogenic process of human colonic epithelium, and RACK1 expressional levels were positively correlated with the malignant degree and lymph node metastasis of colon cancers, and negatively correlated with the patient survival. With a combination of loss-of-function and gain-of-function approaches, we observed that RACK1 promoted colon cancer cell proliferation, inhibited colon cancer cell apoptosis, and enhanced the anchorage-independent and xenograft growth of colon cancer cells. Moreover, we found that RACK1-induced autophagy of colon cancer cells; RACK1-induced autophagy promoted colon cancer cell proliferation and inhibited colon cancer cell apoptosis. Our data suggest that RACK1 acts as an oncogene in colon cancer, and RACK1-induced autophagy promotes proliferation and survival of colon cancer, highlighting the therapeutic potential of autophagy inhibitor in the colon cancer with high RACK1 expression.


Assuntos
Carcinogênese/genética , Neoplasias do Colo/genética , Proteínas de Neoplasias/genética , Receptores de Quinase C Ativada/genética , Apoptose/genética , Autofagia/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Neoplasias do Colo/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Transdução de Sinais/genética
15.
J Stroke Cerebrovasc Dis ; 27(8): 2243-2249, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29752069

RESUMO

OBJECTIVES: The significance of atherosclerotic plaques in the parental artery with low-grade stenosis remains undetermined. We used three-dimensional high-resolution magnetic resonance imaging (3D HR-MRI) to investigate plaque distribution and characteristics of low-grade middle cerebral artery (MCA) stenosis and its clinical relevance with stroke events. METHODS: We retrospectively studied 22 symptomatic patients and 24 asymptomatic patients with low-grade MCA stenosis (<50%). By 3D HR-MRI, each identified plaque was classified as either culprit (plaque on the ipsilateral side of a stroke) or nonculprit (plaques in asymptomatic patients or not within the vascular territory of a stroke). Plaque enhancement grades and distribution were assessed and compared between the groups. The association between plaque enhancement and distribution and ischemic stroke was evaluated. RESULTS: We identified 22 culprit plaques and 31 nonculprit plaques. More culprit plaques showed contrast enhancement compared to the nonculprit plaques (95.5% versus 29.0%, P <.001). Culprit plaques were more frequently superiorly distributed than the nonculprit plaques (46.9% versus 17.5%, P <.01). Contrast enhancement (odds ratio [OR] 17.0, 95% confidence interval [CI] 3.7-77.4) and superior distribution (OR 4.2, 95% CI 1.4-12.1) of a plaque were associated with a recent ischemic stroke, of which single subcortical infarctions accounted for the largest percentage (50%). CONCLUSIONS: Contrast enhancement and superior distribution may serve as indicators of culprit plaques in low-grade MCA stenosis, and they were significantly related to a recent ischemic stroke.


Assuntos
Doenças Arteriais Cerebrais/diagnóstico por imagem , Constrição Patológica/diagnóstico por imagem , Arteriosclerose Intracraniana/diagnóstico por imagem , Artéria Cerebral Média/diagnóstico por imagem , Placa Aterosclerótica/diagnóstico por imagem , Acidente Vascular Cerebral/diagnóstico por imagem , Adulto , Isquemia Encefálica/diagnóstico por imagem , Feminino , Humanos , Imagem Tridimensional , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Razão de Chances , Estudos Retrospectivos , Índice de Gravidade de Doença
16.
Neurol Res ; 40(9): 717-723, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29843579

RESUMO

OBJECTIVE: The role of CD40/CD40 ligand (CD40L) in microvascular thrombosis is now widely accepted. However, the exact mechanisms linking the CD40/CD40L system and the soluble form of CD40L (sCD40L) with microvascular thrombosis are currently a topic of intensive research. The objective of this study was to assess the potential mechanisms in CD40/CD40L system-regulated microvascular thrombosis after focal ischemia/reperfusion (I/R). METHODS: Rats were subjected to 60-min transient middle cerebral artery occlusion (MCAO). The experiments were divided into three groups: sham operation, MCAO, and MCAO + CD40 antagonist. Dynamic changes of serum-free sCD40L levels for 0, 1, 3, 5, 6, and 12 h by ELISA detecting kit after focal I/R were observed, and the CD40 expression levels in both platelet surface and vascular endothelial cell surface were measured by flow cytometry and immunofluorescence, respectively. Cerebral infarct volume was analyzed 12 h after reperfusion. mTOR/S6K signaling was determined by Western blot. RESULTS: A comparison of thrombus formation between MCAO and CD40 antagonist treatment rats revealed a role for CD40 and/or CD40L in the inflammation-enhanced thrombosis responses in both of the platelet and vascular endothelial cell. MCAO rats yielded an acceleration of thrombus formation that was accompanied by increased CD40 levels in serum. The brain infarction was significantly decreased in CD40 antagonist treatment group compared to MCAO model group. The mTOR/S6K signaling was activated in MACO model than that of CD40 antagonist treatment group. CONCLUSIONS: Our findings indicate that CD40/CD40L system contributes to microvascular thrombosis and brain infarction induced by MCAO and reperfusion. The mTOR/S6K signaling pathway is involved in the regulation of cerebral microvasculature after focal I/R by CD40/CD40L. ABBREVIATIONS: AKT: protein kinase B; CD40L: CD40 ligand; CSF: cerebrospinal fluid; FITC: fluorescein isothiocyanate; I/R: ischemia/reperfusion; MCAO: middle cerebral artery occlusion; mTOR: mechanistic target of rapamycin; PE: P-phycoerythrin; sCD40L: soluble form of CD40L; TNF-a: tumor necrosis factor-alpha; WT: wild type.


Assuntos
Antígenos CD40/metabolismo , Ligante de CD40/metabolismo , Infarto da Artéria Cerebral Média/metabolismo , Microvasos/metabolismo , Traumatismo por Reperfusão/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Plaquetas/patologia , Encéfalo/irrigação sanguínea , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Edema Encefálico/metabolismo , Edema Encefálico/patologia , Antígenos CD40/antagonistas & inibidores , Permeabilidade Capilar/efeitos dos fármacos , Permeabilidade Capilar/fisiologia , Modelos Animais de Doenças , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/patologia , Masculino , Microvasos/efeitos dos fármacos , Microvasos/patologia , Ratos Sprague-Dawley , Traumatismo por Reperfusão/patologia , Proteínas Quinases S6 Ribossômicas/metabolismo , Transdução de Sinais
17.
Mol Med Rep ; 17(6): 7902-7910, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29620288

RESUMO

The use of mesenchymal stem cells (MSCs) has been reported to improve outcomes in various types of nervous system diseases, primarily based on their neural regenerative differentiation ability and paracrine effect on different neuroprotective cytokines. Genetically modified MSCs may enhance the paracrine effect and may further improve the cell­based therapeutic outcome of nervous system diseases. Magnetic resonance imaging has been used to monitor distribution and migration of cells labeled with superparamagnetic iron oxide (SPIO) nanoparticles. However, few studies have described the neural differentiation ability of genetically modified and SPIO­labeled MSCs, which is the foundation for cell tracking and cell therapy in vivo. In this study, canine bone marrow­derived MSCs (BMSCs) were initially labeled with SPIO, by culturing with 20 µg/ml SPIO for 24 h, and transfected with the brain­derived neurotrophic factor (BDNF) gene using lentivirus transfection at different multiplicities of infection (MOI) values. The optimized MOI value was demonstrated by cellular viability and enhanced green fluorescent protein (eGFP) rate. Subsequently, the BMSCs were induced to differentiate into neuron­like cells by chemical induction. The results demonstrated that BDNF­overexpressing BMSCs labeled with SPIO can be induced into neuron­like cells with high efficiency and minimal effects on cell viability. Additionally, following neural differentiation, the cells transfected with BDNF and labeled with SPIO expressed significantly higher levels of BDNF and neural markers. The overexpression of BDNF may contribute to neural differentiation of BDNFs, and may have potential benefits for further BMSC­based therapy in vivo.


Assuntos
Diferenciação Celular , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Animais , Biomarcadores , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Diferenciação Celular/genética , Cães , Feminino , Compostos Férricos , Nanopartículas de Magnetita , Masculino , Fenótipo
18.
J Magn Reson Imaging ; 48(1): 66-73, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29083523

RESUMO

BACKGROUND: Intracranial plaque characteristics are associated with stroke events. Differences in plaque features may explain the disconnect between stenosis severity and the presence of ischemic stroke. PURPOSE: To investigate the relationship between plaque characteristics and downstream perfusion changes, and their contribution to the occurrence of cerebral infarction beyond luminal stenosis. STUDY TYPE: Case control. SUBJECTS: Forty-six patients with symptomatic middle cerebral artery (MCA) stenosis (with acute cerebral infarction, n = 30; without acute cerebral infarction, n = 16). FIELD STRENGTH/SEQUENCE: 3.0T with 3D turbo spin echo sequence (3D-SPACE). ASSESSMENT: Luminal stenosis grade, plaque features including lesion T2 and T1 hyperintense components, plaque enhancement grade, and plaque distribution were assessed. Brain perfusion was evaluated on mean transient time maps based on the Alberta Stroke Program Early CT score (MTT-ASPECTS). STATISTICAL TESTS: Plaque features, grade of luminal stenosis, and MTT-ASPECTS were compared between two groups. The association between plaque features and MTT-ASPECTS were assessed using Spearman's correlation analysis. Multivariate logistic regression and receiver operating characteristic (ROC) curves were constructed to assess the effect of significant variables alone and their combination in determining the occurrence of cerebral infarction. RESULTS: Stronger enhanced plaques were associated with downstream lower MTT-ASPECTS (P = 0.010). Plaque enhancement grade (P = 0.039, odds ratio [OR] 5.9, 95% confidence interval [CI] 1.1-32) and MTT-ASPECTS (P = 0.003, OR 2.6, 95% CI 1.4-4.7) were associated with a recent cerebral infarction, whereas luminal stenosis grade was not (P = 0.128). The combination of MTT-ASPECTS and plaque enhancement grade provided incremental information beyond luminal stenosis grade alone. The area under the receiver operating characteristic curve (AUC) improved from 0.535 to 0.921 (P < 0.05). DATA CONCUSION: Strongly enhanced plaques are associated with a higher likelihood of downstream perfusion impairment. Plaque enhancement and perfusion evaluation may play a complementary role to luminal stenosis in determining the occurrence of acute cerebral infarction. LEVEL OF EVIDENCE: 4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Infarto Cerebral/diagnóstico por imagem , Constrição Patológica/diagnóstico por imagem , Imagem por Ressonância Magnética , Artéria Cerebral Média/diagnóstico por imagem , Acidente Vascular Cerebral/diagnóstico por imagem , Adulto , Idoso , Estudos de Casos e Controles , Meios de Contraste/química , Feminino , Taxa de Filtração Glomerular , Humanos , Processamento de Imagem Assistida por Computador , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Arteriosclerose Intracraniana/diagnóstico por imagem , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Perfusão , Placa Aterosclerótica/diagnóstico por imagem , Curva ROC , Estudos Retrospectivos , Risco
19.
BJR Case Rep ; 4(3): 20180007, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31489219

RESUMO

Ectopic meningioma occurring in the region of parapharyngeal space is rare in clinical practice and brings great challenge in its diagnosis. This report details such a case in a 14-year-old girl with neurofibromatosis Type 2, which is a highly infrequent association. The clinical manifestations, imaging findings, and pathological manifestations are described, and the relevant literature is reviewed to highlight characteristic imaging findings of ectopic meningiomas.

20.
Korean J Radiol ; 18(5): 835-843, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28860901

RESUMO

OBJECTIVE: To determine the relationship between intravoxel incoherent motion (IVIM) imaging derived quantitative metrics and serum soluble CD40 ligand (sCD40L) level in an embolic canine stroke model. MATERIALS AND METHODS: A middle cerebral artery occlusion model was established in 24 beagle dogs. Experimental dogs were divided into low- and high-sCD40L group according to serum sCD40L level at 4.5 hours after establishing the model. IVIM imaging was scanned at 4.5 hours after model establishment using 10 b values ranging from 0 to 900 s/mm2. Quantitative metrics diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) of ischemic lesions were calculated. Quantitative metrics of ischemic lesions were normalized by contralateral hemisphere using the following formula: normalized D = Dstroke / Dcontralateral. Differences in IVIM metrics between the low- and high-sCD40L groups were compared using t test. Pearson's correlation analyses were performed to determine the relationship between IVIM metrics and serum sCD40L level. RESULTS: The high-sCD40L group showed significantly lower f and normalized f values than the low-sCD40L group (f, p < 0.001; normalized f, p < 0.001). There was no significant difference in D*, normalized D*, D, or normalized D value between the two groups (All p > 0.05). Both f and normalized f values were negatively correlated with serum sCD40L level (f, r = -0.789, p < 0.001; normalized f, r = -0.823, p < 0.001). However, serum sCD40L level had no significant correlation with D*, normalized D*, D, or normalized D (All p > 0.05). CONCLUSION: The f value derived from IVIM imaging was negatively correlated with serum sCD40L level. f value might serve as a potential imaging biomarker to assess the formation of microvascular thrombosis in hyperacute period of ischemic stroke.


Assuntos
Encéfalo/fisiopatologia , Ligante de CD40/sangue , Imagem de Difusão por Ressonância Magnética , Acidente Vascular Cerebral/patologia , Animais , Encéfalo/diagnóstico por imagem , Modelos Animais de Doenças , Cães , Feminino , Masculino , Acidente Vascular Cerebral/diagnóstico por imagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA