Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Digit Imaging ; 36(4): 1910-1918, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37039950

RESUMO

It is difficult to accurately understand the angioarchitecture of cerebral arteriovenous malformations (CAVMs) before surgery using existing imaging methods. This study aimed to evaluate the ability of the stereoscopic virtual reality display system (SVRDS) to display the angioarchitecture of CAVMs by comparing its accuracy with that of the conventional computed tomography workstation (CCTW). Nineteen patients with CAVM confirmed on digital subtraction angiography (DSA) or during surgery were studied. Computed tomography angiography images in the SVRDS and CCTW were retrospectively analyzed by two experienced neuroradiologists using a double-blind method. Angioarchitectural parameters, such as the location and size of the nidus, type and number of the arterial feeders and draining veins, and draining pattern of the vessels, were recorded and compared. The diameter of the nidus ranged from 1.1 to 9 cm. Both CCTW and SVRDS correctly diagnosed the location of the nidus in 19 patients with CAVM. Among the 19 patients, 35 arterial feeders and 25 draining veins were confirmed on DSA and during surgery. With the DSA and intraoperative results as the gold standard bases, the CCTW misjudged one arterial feeder and one draining vein and missed three arterial feeders and two draining veins; meanwhile, the SVRDS missed only two arterial feeders. SVRDS had some advantages in displaying nidus, arterial branches, and draining veins of the CAVM compared with CCTW, as well as SVRDS could more intuitively display the overall angio-architectural spatial picture of CAVM.


Assuntos
Malformações Arteriovenosas Intracranianas , Realidade Virtual , Humanos , Estudos Retrospectivos , Malformações Arteriovenosas Intracranianas/diagnóstico por imagem , Malformações Arteriovenosas Intracranianas/cirurgia , Angiografia Cerebral , Tomografia Computadorizada por Raios X/métodos , Angiografia Digital
2.
J Digit Imaging ; 36(1): 114-123, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36085330

RESUMO

The accuracy of computed tomography angiography (CTA) image interpretation depends on the radiologist. This study aims to develop a new method for automatically detecting intracranial aneurysms from CTA images using deep learning, based on a convolutional neural network (CNN) implemented on the DeepMedic platform. Ninety CTA scans of patients with intracranial aneurysms are collected and divided into two datasets: training (80 subjects) and test (10 subjects) datasets. Subsequently, a deep learning architecture with a three-dimensional (3D) CNN model is implemented on the DeepMedic platform for the automatic segmentation and detection of intracranial aneurysms from the CTA images. The samples in the training dataset are used to train the CNN model, and those in the test dataset are used to assess the performance of the established system. Sensitivity, positive predictive value (PPV), and false positives are evaluated. The overall sensitivity and PPV of this system for detecting intracranial aneurysms from CTA images are 92.3% and 100%, respectively, and the segmentation sensitivity is 92.3%. The performance of the system in the detection of intracranial aneurysms is closely related to their size. The detection sensitivity for small intracranial aneurysms (≤ 3 mm) is 66.7%, whereas the sensitivity of detection for large (> 10 mm) and medium-sized (3-10 mm) intracranial aneurysms is 100%. The deep learning architecture with a 3D CNN model on the DeepMedic platform can reliably segment and detect intracranial aneurysms from CTA images with high sensitivity.


Assuntos
Aprendizado Profundo , Aneurisma Intracraniano , Humanos , Angiografia por Tomografia Computadorizada , Tomografia Computadorizada por Raios X/métodos , Angiografia Digital/métodos , Angiografia Cerebral/métodos , Sensibilidade e Especificidade
3.
Cell Physiol Biochem ; 47(4): 1411-1421, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29929190

RESUMO

BACKGROUND/AIMS: Alcohol consumption has been shown to cause neuroinflammation and increase a variety of immune-related signaling processes. Microglia are a crucial part of alcohol-induced neuroinflammation and undergo apoptosis. Even though the importance of these inflammatory processes in the effects of alcohol-related neurodegeneration have been established, the mechanism of alcohol-induced microglia apoptosis is unknown. In prior research, we discovered that alcohol increases expression of salt-inducible kinase 1 (SIK1) in rodent brain tissue. In this study, we sought to determine what role SIK1 expression plays in alcohol-induced neuroinflammation as well as whether and by what mechanism it regulates microglia apoptosis. METHODS: Adult C57BL/6 mice were divided into four groups and for 3 weeks treated with either 0%, 5%, 10%, or 15% alcohol during 3 hour periods. The mice were sacrificed and their brains excised for analysis. Additionally, primary microglia were isolated from neonatal mice. SIK1 expression in alcohol-treated brain tissue and microglia was analyzed via RT-PCR and western blotting. TUNEL staining, caspase-3, and caspase-9 activity assays were performed to evaluate microglial apoptosis. Cell fluorescence staining and NF-κB luciferase activity assays were used to evaluate the effects of SIK1 expression on the NF-κB signaling pathway. RESULTS: SIK1 expression was increased in the brains of mice that consumed alcohol, and this effect was seen in mouse primary microglia. SIK1 knockdown in microglia increased alcohol-induced apoptosis in these cells. Furthermore, SIK1 reduced NF-κB signaling pathway factors, and SIK1 knockdown in microglia promoted alcohol-induced NF-κB activity. TUNEL staining, caspase-3, and caspase-9 activity assays consistently revealed that alcohol-induced microglial apoptosis was inhibited by depletion of p65. Finally, we determined that NF-κB signaling is required for alcohol-induced, SIK1-mediated apoptosis in microglia. CONCLUSION: This study establishes for the first time not only that SIK1 is crucial to regulating alcohol-induced microglial apoptosis, but also that the NF-κB signaling pathway is required for its activity. Overall, our results help elucidate mechanisms of alcohol-induced neuroinflammation.


Assuntos
Apoptose/efeitos dos fármacos , Etanol/efeitos adversos , Microglia/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Etanol/farmacologia , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Camundongos , Microglia/patologia , Proteínas Serina-Treonina Quinases
4.
Tumour Biol ; 37(1): 1097-104, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26271668

RESUMO

Glioblastoma is a type of primary brain tumor with poor prognosis. The hallmark phenotype of glioblastoma is its aggressive invasion. Understanding the molecular mechanism of the invasion behavior of glioblastoma is essential for the development of effective treatment of the disease. In our present study, we found that the expression levels of a homeobox transcription factor, MSX1, were significantly reduced in glioblastoma compared to normal brain tissues. The levels of MSX1 in glioblastoma tissues were also correlated with the survival of the patients. In cultured glioblastoma cells, MSX1 was a negative regulator of cell migration and invasion. Loss of MSX1 enhanced cell migration and induced mesenchymal transition as characterized by the downregulation of E-cadherin and the upregulation of N-cadherin. Overexpression of MSX1 on the other hand led to the inhibition of both cell migration and mesenchymal transition. We also found that MSX1 was able to inhibit the Wnt/ß-catenin signaling pathway, and that the ability to regulate the Wnt/ß-catenin signaling pathway is critical for MSX1 to suppress glioblastoma cell migration and invasion.


Assuntos
Glioblastoma/metabolismo , Fator de Transcrição MSX1/metabolismo , Via de Sinalização Wnt , Adulto , Idoso , Moléculas de Adesão Celular/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/mortalidade , Glioblastoma/patologia , Humanos , Fator de Transcrição MSX1/genética , Masculino , Pessoa de Meia-Idade , Prognóstico
5.
J Drug Target ; 30(2): 208-218, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34236257

RESUMO

Ferroptosis is a regulated cell death pathway which depends on iron. Ferroptosis can be induced by limiting intracellular glutathione (GSH) synthesis, or inhibiting the activity of GPX4, or increasing intracellular accumulation of PE-AA-OOH, all of which involve NADPH. Therefore, NADPH depletion, excessive PE-AA-OOH, and GPX4 deficiency are generally considered to be the main characteristics of ferroptosis. In this research, the novel self-assembly nanomicelles modified by maltose ligand (Malt-PEG-Abz@RSL3) with superior nano characteristics were designed and fabricated. Malt-PEG-Abz@RSL3 micelles achieved active targeted drug delivery due to the high expression of glucose transporter (GLUT) and high uptake by HepG2 cells. Maltose-polyethylene glycol broke to release RSL3 for inhibiting GPX4 activity when Malt-PEG-Abz@RSL3 micelles entered the cells. Meanwhile, key coenzyme NADPH that participated in synthesis of GSH and Trx(SH)2 was depleted by azobenzene moiety, resulting in decreasing GSH and Trx(SH)2, which dually induced ferroptosis in tumour cells and promoted cell apoptosis.


Assuntos
Ferroptose , Carbolinas , Células Hep G2 , Humanos , Micelas , NADP
6.
Front Mol Biosci ; 8: 784288, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35242810

RESUMO

Studies of key metabolite variations and their biological mechanisms in cerebral infarction (CI) have increased our understanding of the pathophysiology of the disease. However, how metabolite variations in different periods of CI influence these biological processes and whether key metabolites from different periods may better predict disease progression are still unknown. We performed a systematic investigation using the metabonomics method. Various metabolites in different pathways were investigated by serum metabolic profiling of 143 patients diagnosed with CI and 59 healthy controls. Phe-Phe, carnitine C18:1, palmitic acid, cis-8,11,14-eicosatrienoic acid, palmitoleic acid, 1-linoleoyl-rac-glycerol, MAG 18:1, MAG 20:3, phosphoric acid, 5α-dihydrotestosterone, Ca, K, and GGT were the major components in the early period of CI. GCDCA, glycocholate, PC 36:5, LPC 18:2, and PA showed obvious changes in the intermediate time. In contrast, trans-vaccenic acid, linolenic acid, linoleic acid, all-cis-4,7,10,13,16-docosapentaenoic acid, arachidonic acid, DHA, FFA 18:1, FFA 18:2, FFA 18:3, FFA 20:4, FFA 22:6, PC 34:1, PC 36:3, PC 38:4, ALP, and Crea displayed changes in the later time. More importantly, we found that phenylalanine metabolism, medium-chain acylcarnitines, long-chain acylcarnitines, choline, DHEA, LPC 18:0, LPC 18:1, FFA 18:0, FFA 22:4, TG, ALB, IDBIL, and DBIL played vital roles in the development of different periods of CI. Increased phenylacetyl-L-glutamine was detected and may be a biomarker for CI. It was of great significance that we identified key metabolic pathways and risk metabolites in different periods of CI different from those previously reported. Specific data are detailed in the Conclusion section. In addition, we also explored metabolite differences of CI patients complicated with high blood glucose compared with healthy controls. Further work in this area may inform personalized treatment approaches in clinical practice for CI by experimentally elucidating the pathophysiological mechanisms.

7.
Clin Neurol Neurosurg ; 170: 93-98, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29753884

RESUMO

OBJECTIVE: This study aimed to compare the diagnostic performance of the stereoscopic virtual reality display system with the conventional computed tomography (CT) workstation and three-dimensional rotational angiography (3DRA) for intracranial aneurysm detection and characterization, with a focus on small aneurysms and those near the bone. PATIENTS AND METHODS: First, 42 patients with suspected intracranial aneurysms underwent both 256-row CT angiography (CTA) and 3DRA. Volume rendering (VR) images were captured using the conventional CT workstation. Next, VR images were transferred to the stereoscopic virtual reality display system. Two radiologists independently assessed the results that were obtained using the conventional CT workstation and stereoscopic virtual reality display system. The 3DRA results were considered as the ultimate reference standard. RESULTS: Based on 3DRA images, 38 aneurysms were confirmed in 42 patients. Two cases were misdiagnosed and 1 was missed when the traditional CT workstation was used. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the conventional CT workstation were 94.7%, 85.7%, 97.3%, 75%, and99.3%, respectively, on a per-aneurysm basis. The stereoscopic virtual reality display system missed a case. The sensitivity, specificity, PPV, NPV, and accuracy of the stereoscopic virtual reality display system were 100%, 85.7%, 97.4%, 100%, and 97.8%, respectively. No difference was observed in the accuracy of the traditional CT workstation, stereoscopic virtual reality display system, and 3DRA in detecting aneurysms. CONCLUSION: The stereoscopic virtual reality display system has some advantages in detecting small aneurysms and those near the bone. The virtual reality stereoscopic vision obtained through the system was found as a useful tool in intracranial aneurysm diagnosis and pre-operative 3D imaging.


Assuntos
Angiografia Cerebral/métodos , Imageamento Tridimensional/métodos , Aneurisma Intracraniano/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Realidade Virtual , Adulto , Idoso , Feminino , Humanos , Aneurisma Intracraniano/cirurgia , Masculino , Pessoa de Meia-Idade
8.
Artigo em Zh | MEDLINE | ID: mdl-15830851

RESUMO

OBJECTIVE: To find out current distribution of Oncomelania snails and Schistosoma infection in snails in Zhejiang Province, so as to improve the project of schistosomiasis control. METHODS: Investigation spots were selected by stratified cluster sampling method, 100 villages of 34 counties were selected from 7106 villages of 55 counties as survey spots. Synchronously systematic and environmental samplings were used for the survey. Snails were dissected to determine the infection status and spots with sham snails were set to assess the quality of the survey. RESULTS: The result showed that snails were found in 223 strips, 1572 frames and 73,300 m2 area in 32 villages of 21 counties. Snails were found in an area covering 72,640 m2 in 29 villages of 18 counties in hilly region, which accounted for 99.1% of total snail habitats. The significantly larger area with snails was revealed in hilly region than that in water network region (t = 3.04, P < 0.01). 1st, 2nd strata occupied 71,680 m2 snail area, which accounted for 97.8% of total snail area, much higher than that in the 3rd stratum (t = 3.71 , P < 0.01). Snail habitats in the irrigation ditches and canals accounted for 62.6% of total snail area, significantly higher than that of farmland (t = 3.02, P < 0.01). No snails were found infected among 7892 living snails by dissection. The theory value of snail area in Zhejiang Province was 1,361,940 m2. CONCLUSION: It is estimated that the snail-ridden area is about 1,500,000-2,000,000 m2 in the Province, mostly found in the villages of hilly region with a record of snail habitats during the recent 4 years and the primary environment of the snail areas were ditches and canals. No infected snails were found from the survey.


Assuntos
Reservatórios de Doenças , Caramujos , Animais , China , Estudos de Amostragem , Esquistossomose/prevenção & controle
9.
Naunyn Schmiedebergs Arch Pharmacol ; 386(1): 61-70, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23192284

RESUMO

It is well known that puerarin attenuates ischemia-reperfusion injury and promotes function recovery of ischemic region. However, due to its reverse physiochemical properties, puerarin does not easily cross the blood-brain barrier. The aim of the present study is to create puerarin nanoparticles which increase and prolong the puerarin concentration in the brain. Using emulsion solvent evaporation techniques, we designed puerarin-loaded poly(D,L-lactic-co-glycolic acid) nanoparticles. Hydroxypropyl beta cyclodextrin (HP-ß-CD) was used to increase the solubility of puerarin and gelatin to enhance viscosity of inner water phase, which improved puerarin entrapment. The drug release kinetics and nanoparticle degradation in phosphate buffered saline (PBS) were analyzed by electronic microscopy and high-performance liquid chromatography. Computerized tomography scans were used to detect the infarction volume and electroencephalogram (EEG) was recorded to estimate the recovery of brain function. The results showed that the combined HP-ß-CD and gelatin significantly improved the entrapment efficiency. The infarction volume was significantly decreased on days 3 and 7 after the administration of puerarin nanoparticles compared with that of control and pure puerarin. EEG was also significantly improved. Puerarin nanoparticles are potentially applicable for the brain injury induced by ischemic-reperfusion.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Isoflavonas/administração & dosagem , Ácido Láctico/química , Ácido Poliglicólico/química , beta-Ciclodextrinas/química , 2-Hidroxipropil-beta-Ciclodextrina , Animais , Disponibilidade Biológica , Barreira Hematoencefálica/metabolismo , Isquemia Encefálica/patologia , Cromatografia Líquida de Alta Pressão , Portadores de Fármacos/química , Gelatina/química , Isoflavonas/farmacocinética , Isoflavonas/farmacologia , Masculino , Nanopartículas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Wistar , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/patologia , Solubilidade , Fatores de Tempo , Distribuição Tecidual , Tomografia Computadorizada por Raios X , Vasodilatadores/administração & dosagem , Vasodilatadores/farmacocinética , Vasodilatadores/farmacologia , Viscosidade
10.
Eur J Pharm Biopharm ; 84(3): 505-16, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23376242

RESUMO

Targeting of intracerebral functional regions has been limited by the inability to transport drugs across the blood-brain barrier (BBB) and by poor accumulation in these regions. To overcome these hurdles, liposomes modified with P-aminophenyl-α-d-mannopyranoside (MAN) were used as a fluorescent dye carrier through the BBB and used the specific distribution of liposomes (LIP) modified with MAN (MAN-LIP) to target various functional regions of the brain. An in vitro BBB model was established to evaluate the transendothelial ability of MAN-LIP, and liposomes uptake by C6 glioma cells was analyzed by flow cytometry and live cell imaging. Liposome targeting was evaluated using in vivo and ex vivo imaging. After MAN-LIP administration, the transendothelial ability and the delivery of fluorescent dye to the brain significantly increased. MAN-LIP concentrated in the cortex at 4 h, shifting distribution to the cerebellum and brainstem at 12 h. The fluorescence intensity in the hippocampus and pontine nuclei remained high and stable over a period of 12 h. The results demonstrate that MAN-LIP is able to enhance cellular uptake in vitro and also promotes penetration through the BBB and accumulation in the brain with a distinct spatio-temporal pattern.


Assuntos
Compostos de Anilina/química , Encéfalo/fisiologia , Portadores de Fármacos , Lipossomos/química , Manosídeos/química , Animais , Barreira Hematoencefálica , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Meios de Cultura/química , Endocitose , Citometria de Fluxo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA