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1.
Appl Opt ; 61(26): 7579-7586, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-36256356

RESUMO

Nickel-based superalloys are widely used in key hot-end components such as aero engines and industrial gas turbines due to their excellent comprehensive properties. Real-time monitoring of engine blades and other structures in high-temperature environments can promptly discover possible internal damage to the structure. Optical fiber sensing technology has unique advantages that traditional electrical sensors do not have, such as anti-electromagnetic interference, small size, light weight, and corrosion resistance. The technology is gradually replacing traditional methods and becoming an important means of structural health monitoring. We propose an optical fiber sensor and assembly method that can be used to measure the strain of a nickel-based directionally solidified superalloy in a high-temperature environment more accurately. The proposed technology is simple to manufacture and also has low cost and a high survival rate, which is of great significance for high-temperature strain measurements in aerospace and other fields.

2.
Haematologica ; 106(11): 2927-2939, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-33054136

RESUMO

Diffuse large B-cell lymphoma (DLBCL) is the most common Non-Hodgkin's lymphoma and is characterized by a remarkable heterogeneity with diverse variants that can be identified histologically and molecularly. Large-scale gene expression profiling studies have identified the germinal center B-cell (GCB-) and activated B-cell (ABC-) subtypes. Standard chemo-immunotherapy remains standard front line therapy, curing approximately two thirds of patients. Patients with refractory disease or those who relapse after salvage treatment have an overall poor prognosis highlighting the need for novel therapeutic strategies. Transducin ß-like protein 1 (TBL1) is an exchange adaptor protein encoded by the TBL1X gene and known to function as a master regulator of the Wnt signalling pathway by binding to ß-CATENIN and promoting its downstream transcriptional program. Here, we show that, unlike normal B-cells, DLBCL cells express abundant levels of TBL1 and its overexpression correlates with poor clinical outcome regardless of DLBCL molecular subtype. Genetic deletion of TBL1 and pharmacological approach using tegavivint, a first-in-class small molecule targeting TBL1 (Iterion Therapeutics), promotes DLBCL cell death in vitro and in vivo. Through an integrated genomic, biochemical, and pharmacologic analyses, we characterized a novel, ß-CATENIN independent, post-transcriptional oncogenic function of TBL1 in DLBCL where TBL1 modulates the stability of key oncogenic proteins such as PLK1, MYC, and the autophagy regulatory protein BECLIN-1 through its interaction with a SKP1-CUL1-F-box (SCF) protein supercomplex. Collectively, our data provide the rationale for targeting TBL1 as a novel therapeutic strategy in DLBCL.


Assuntos
Linfoma Difuso de Grandes Células B , Transducina , Carcinogênese , Perfilação da Expressão Gênica , Humanos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Recidiva Local de Neoplasia , Prognóstico , Transducina/genética
3.
Immunopharmacol Immunotoxicol ; 43(6): 749-757, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34591732

RESUMO

OBJECTIVE: Cerebral infarction (CI) is the mayor reason of death in China. Reperfusion is the only immediate treatment for acute cerebral infarction. However, blood reperfusion recovery may cause ischemia-reperfusion (I/R) injuries. The purpose of this study was to investigate the effects of Tetrandrine (TTD) and 3-n-Butylphthalide (NBP) on cerebral I/R injury. MATERIALS AND METHODS: I/R was used to establish CI model in vivo. TTD was performed to analyze cerebral infarction volume. OGD was applied to establish CI model in vitro. Flow cytometry and TUNEL assays were utilized to determine the cell death. ELISA was conducted to determine the release of cytokines. mRNA and protein expressions were detected using qRT-PCR and western blot. RESULTS: We found that NBP + TTD treatment significantly reduced cerebral infarction volume and inhibited the death of neurons in vivo. Moreover, NBP + TTD treatment suppressed the apoptosis and inflammatory response of neurons in vitro. Additionally, NBP + TTD suppressed the expression of activator transcription factor 2 (ATF2). However, overexpression of ATF2 contributed to the degeneration of neurons. Moreover, ATF2 transcriptionally activated Toll-like receptor 4 (TLR4). NBP + TTD inactivated ATF2/TLR4 signaling. CONCLUSIONS: Taken together, TTD combined with NBP protected against cerebral infarction by inhibiting the inflammatory response and neuronal cell apoptosis via inactivating ATF2/TLR4 signaling pathways. This may provide an alternative for I/R injury.


Assuntos
Fator 2 Ativador da Transcrição/antagonistas & inibidores , Benzofuranos/administração & dosagem , Benzilisoquinolinas/administração & dosagem , Isquemia Encefálica/prevenção & controle , Traumatismo por Reperfusão/prevenção & controle , Receptor 4 Toll-Like/antagonistas & inibidores , Fator 2 Ativador da Transcrição/metabolismo , Animais , Isquemia Encefálica/metabolismo , Células Cultivadas , Quimioterapia Combinada , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores/administração & dosagem , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Receptor 4 Toll-Like/metabolismo
4.
bioRxiv ; 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36747748

RESUMO

Adrenocortical carcinoma (ACC) has a poor prognosis, and no new drugs have been identified in decades. The absence of drug development can partly be attributed to a lack of preclinical models. Both animal models and 2D cell cultures of ACC fail to accurately mimic the disease, as animal physiology is inherently different than humans, and 2D cultures fail to represent the crucial 3D architecture. Organoids and other small 3D in vitro models of tissues or tumors can model certain complexities of human in vivo biology; however, this technology has largely yet to be applied to ACC. In this study, we describe the generation of 3D tumor constructs from an established ACC cell line, NCI-H295R. NCI-H295R cells were encapsulated to generate 3D ACC constructs. Tumor constructs were assessed for biomarker expression, viability, proliferation, and cortisol production. In addition, matrix metalloproteinase (MMP) functionality was assessed directly using fluorogenic MMP-sensitive biosensors and through infusion of NCI-H295R cells into a metastasis-on-a-chip microfluidic device platform. ACC tumor constructs showed expression of biomarkers associated with ACC, including SF-1, Melan A, and inhibin alpha. Treatment of ACC tumor constructs with chemotherapeutics demonstrated decreased drug sensitivity compared to 2D cell culture. Since most tumor cells migrate through tissue using MMPs to break down extracellular matrix, we validated the utility of ACC tumor constructs by integrating fluorogenic MMP-sensitive peptide biosensors within the tumor constructs. Lastly, in our metastasis-on-a-chip device, NCI-H295R cells successfully engrafted in a downstream lung cell line-based construct, but invasion distance into the lung construct was decreased by MMP inhibition. These studies, which would not be possible using 2D cell cultures, demonstrated that NCI-H295R cells secreted active MMPs that are used for invasion in 3D. This work represents the first evidence of a 3D tumor constructs platform for ACC that can be deployed for future mechanistic studies as well as development of new targets for intervention and therapies.

5.
Sci Rep ; 13(1): 15508, 2023 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-37726363

RESUMO

Adrenocortical carcinoma (ACC) has a poor prognosis, and no new drugs have been identified in decades. The absence of drug development can partly be attributed to a lack of preclinical models. Both animal models and 2D cell cultures of ACC fail to accurately mimic the disease, as animal physiology is inherently different than humans, and 2D cultures fail to represent the crucial 3D architecture. Organoids and other small 3D in vitro models of tissues or tumors can model certain complexities of human in vivo biology; however, this technology has largely yet to be applied to ACC. In this study, we describe the generation of 3D tumor constructs from an established ACC cell line, NCI-H295R. NCI-H295R cells were encapsulated to generate 3D ACC constructs. Tumor constructs were assessed for biomarker expression, viability, proliferation, and cortisol production. In addition, matrix metalloproteinase (MMP) functionality was assessed directly using fluorogenic MMP-sensitive biosensors and through infusion of NCI-H295R cells into a metastasis-on-a-chip microfluidic device platform. ACC tumor constructs showed expression of biomarkers associated with ACC, including SF-1, Melan A, and inhibin α. Treatment of ACC tumor constructs with chemotherapeutics demonstrated decreased drug sensitivity compared to 2D cell culture. Since most tumor cells migrate through tissue using MMPs to break down extracellular matrix, we validated the utility of ACC tumor constructs by integrating fluorogenic MMP-sensitive peptide biosensors within the tumor constructs. Lastly, in our metastasis-on-a-chip device, NCI-H295R cells successfully engrafted in a downstream lung cell line-based construct, but invasion distance into the lung construct was decreased by MMP inhibition. These studies, which would not be possible using 2D cell cultures, demonstrated that NCI-H295R cells secreted active MMPs that are used for invasion in 3D. This work represents the first evidence of a 3D tumor constructs platform for ACC that can be deployed for future mechanistic studies as well as development of new targets for intervention and therapies.


Assuntos
Neoplasias do Córtex Suprarrenal , Carcinoma Adrenocortical , Animais , Humanos , Carcinoma Adrenocortical/tratamento farmacológico , Neoplasias do Córtex Suprarrenal/tratamento farmacológico , Proteólise , Transporte Biológico , Metaloproteinases da Matriz
6.
Mol Carcinog ; 51(2): 150-64, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21480393

RESUMO

A disintegrin and metalloproteinase-17 (ADAM17) is involved in proteolytic ectodomain shedding of several membrane-bound growth factors and cytokines. The expression and activity of ADAM17 increase under some pathological conditions such as stroke and cancer. ADAM17 promotes neural progenitor cell migration and contributes to neurogenesis after stroke and breast cancer growth and invasion. In the present study, we sought to elucidate whether ADAM17 contributes to glioma progression. To this end, we examined the role of ADAM17 in the proliferation, invasion, and tube formation of U87 human glioma cells in vitro and tumor growth in vivo. Stable transfection of the U87 cell line with either a plasmid for over-expression of human ADAM17, or a siRNA to ADAM17 was employed in this study to establish high- or low-ADAM17 expression in glioma cells, respectively. For study of mechanism, the ADAM17 inhibitor TAPI-2 and the PI3K-AKT inhibitor LY294002 were used to counteract high-ADAM17 expression and the activated PI3K-AKT pathway, respectively. Proliferation of glioma cells were tested by thiazolyl blue tetrazolium bromide (MTT) assay, bromodeoxyuridine incorporation assay, growth curve, and sulforhodamine B assay. Matrigel invasion assays were used to assess the ability of U87 cells to penetrate the extracellular matrix (ECM). A Matrigel tube formation assay was performed to test capillary tube formation ability. EGFR-PI3K-Akt pathway activation in U87 cells under different ADAM17 expression levels were tested by Western blot. Our data show that ADAM17 promotes the U87 malignant phenotype by increased proliferation, invasion, angiogenesis, and in vivo tumor growth. Tumor growth in nude mice was significantly inhibited by ADAM17 inhibitor and A17-shRNA in vivo transfection. TGF-α, VEGF secretion, and VEGF expression was increased by ADAM17 and counteracted by ADAM17 siRNA, TAPI-2, and LY294002 in U87 cells. ADAM17 activated, whereas ADAM17 siRNA, TAPI-2, and LY294002 deactivated the EGFR-PI3K-AKT signal pathway, which correlated with U87 cell malignant phenotype changes. This study suggests ADAM17 contributes to glioma progression through activation of the EGFR-PI3K-AKT signal pathway.


Assuntos
Proteínas ADAM/fisiologia , Neoplasias Encefálicas/patologia , Glioma/patologia , Proteínas ADAM/genética , Proteína ADAM17 , Animais , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Camundongos , Camundongos Nus , Fenótipo , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Fator A de Crescimento do Endotélio Vascular/genética
7.
Medicine (Baltimore) ; 101(39): e30867, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36181069

RESUMO

BACKGROUND: Thymic epithelial tumors (TETs) originate in the thymic epithelial cell, including thymoma and thymic carcinoma. Surgical resection is the first choice for most patients. However, some studies have shown that the factors affecting the prognosis of these patients are not consistent. To evaluate prognostic factors in patients with surgically resected thymic epithelial tumors, we performed a meta-analysis. METHODS: We searched the Chinese biomedical literature database, Pubmed, Embase, Cochrane Library and other electronic databases. Studies including postoperative overall survival (OS) and predictors of TETs were included. We made a comprehensive analysis the hazard ratios (HRs) through a single proportional combination. HRs were combined using single proportion combinations. RESULTS: The meta-analysis included 11,695 patients from 26 studies. The pooled OS was 84% at 5 years and 73% at 10 years after TETs operation. The age as continuous-year (HR 1.04, 95% confidence interval (CI) 1.02-1.04), incomplete resection (HR 4.41, 95% CI 3.32-5.85), WHO histologic classification (B2/B3 vs A/AB/B1 HR 2.76, 95% CI 1.25-6.21), Masaoka Stage (stage III/IV vs I/II HR 2.74, 95% CI 2.12-3.55,) were the poor prognostic factors. CONCLUSIONS: For patients with TETs after surgical resection, advanced age, incomplete resection, WHO classification B2/B3, and higher Masaoka stage are risk factors for poor prognosis.


Assuntos
Neoplasias Epiteliais e Glandulares , Timoma , Neoplasias do Timo , Humanos , Estadiamento de Neoplasias , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Epiteliais e Glandulares/cirurgia , Prognóstico , Estudos Retrospectivos , Timoma/patologia , Neoplasias do Timo/patologia
8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(9): 2431-6, 2011 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-22097843

RESUMO

At room temperature, the mid-infrared spectra of geometrically frustrated natural atacamite (hydroxyl copper chloride, beta-Cu2(OH)3Cl) in the range of 4 000-400 cm(-1) were measured by FTIR spectrometers, and meanwhile its Raman spectrum in the range of 4 000-95 cm(-1) was obtained by Jobin Yvon LabRAM HR800 Raman spectrometer. According to its crystal structure parameters, the authors confirmed the characteristic peaks of sample 4 000-2 500-1 000 cm(-1) in the functional group region and 1 000-550-200-95 cm(-1) in the fingerprint region, and also explored its microscopic origin Five distinct regions were assigned: the hydroxyl stretching vibration v(O-H) determined by the overall environment around the hydroxyl group; the overtones generated by the sum or multiplication of fundamental frequencies of hydroxyl bending vibration; the hydroxyl bending vibration modes delta(O-H) of the combination of delta(Cu-O-H) and delta(O-H...HCl); the vibration modes of strongly bonded planar CuO4 units; the vibration modes of weakly bonded linear-triatomic chain Cl-Cu-O/Cl. The bands were assigned in accordance with its crystal structure parameters, which is more reasonable to establish the relationship between its molecular structure and its respective spectral properties.

9.
J Phys Condens Matter ; 33(27)2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34047278

RESUMO

We report on an investigation of the temperature-dependent ordering of the hydrogen/deuterium atoms in geometrically frustrated magnets Co2(OH)3Br and its deuterated Co2(OD)3Br, to shed light on the origin of the newly-identified ferroelectricity using Raman spectroscopy. Significant changes in the Raman frequencies and line-widths of the Raman-active modes were observed below ∼260 K in Co2(OD)3Br and ∼240 K in Co2(OH)3Br, respectively, the analysis of which revealed strong spin-phonon couplings in this system. Further, for Co2(OD)3Br, six new phonon bands appeared below around 260 K, with the corresponding intensities obeying a power-law equationI∝1-T/Tc2ßwhereinTc= 260 K, suggesting that an ordering process occurred below ∼260 K. The ordering process subsequently affected the local structure and brought out the reported ferroelectric phase, which is considered as frustrated. Meanwhile, in Co2(OH)3Br, only one new band was observed below ∼240 K, followed by two 'softened' modes correlated to the [OH] sub-lattice below ∼185 K, wherein an incomplete ordering was suggested. The present work reveals a new multiferroic system combining geometrically frustrated magnetism and deuterium ordering-type ferroelectricity.

10.
J Neurosci Res ; 88(2): 304-14, 2010 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-19681167

RESUMO

We employed lentivirus-based doublecortin (DCX), as a glioma suppressor gene therapy in an intracranial glioma tumor xenograft model in nude rats. Single DCX-expressing lentivirus was directly administered into the tumor on day 8 after U87 tumor cell implantation. DCX treatment significantly reduced U87 glioma tumor volume (approximately 60%) on day 14 after DCX lentivirus injection and significantly improved median survival of tumor-bearing nude rats. DCX synthesis induced neuronal markers MAP2, TUJ1, and PSA-NCAM and the glial marker glial fibrillary acidic protein (GFAP) in the implanted U87 glioma tumors. DCX synthesis induced GFAP that colocalized with tubulin in the mitotic stage, inhibited cleavage furrow during cytokinesis, and blocked mitosis in glioma cells. DCX lentivirus infection did not induce apoptosis but significantly inhibited expression of the proliferation marker Ki-67 and the blood vessel marker von-Willebrand factor (vWF). U87 and other glioma cells except for brain tumor stem cells (BTSCs) do not express neuronal markers or both neuronal and glial markers. DCX-synthesizing glioma cells express a phenotype of antiangiogenic BTSC-like cells with terminal differentiation that causes remission of glioma cells by blocking mitosis via a novel DCX/GFAP pathway. Direct local delivery of lentivirus-based DCX gene therapy is a potential differentiation-based therapeutic approach for the treatment of glioma.


Assuntos
Neoplasias Encefálicas/terapia , Terapia Genética/métodos , Glioma/terapia , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/uso terapêutico , Neuropeptídeos/genética , Neuropeptídeos/uso terapêutico , Animais , Astrócitos/patologia , Astrócitos/fisiologia , Encéfalo/patologia , Encéfalo/fisiopatologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Linhagem Celular Tumoral , Citocinese/fisiologia , Proteínas do Domínio Duplacortina , Proteína Duplacortina , Vetores Genéticos , Proteína Glial Fibrilar Ácida/metabolismo , Glioma/patologia , Glioma/fisiopatologia , Lentivirus/genética , Transplante de Neoplasias , Neovascularização Patológica/patologia , Neovascularização Patológica/fisiopatologia , Neovascularização Patológica/terapia , Neurônios/patologia , Neurônios/fisiologia , Ratos , Ratos Nus , Resultado do Tratamento
11.
Cancer Invest ; 28(10): 1024-30, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20874002

RESUMO

Human miR-146b-5p is located on chromosome 10q24.3. Loss of the 10q24-26 region is frequently observed in gliomas. Here, we report that miR-146b-5p suppresses expression of epidermal growth factor receptor (EGFR) in human glioblastoma cell lines. Introduction of miR-146b-5p decreases cell invasion, migration, and phosphorylation of protein kinase B (AKT). MiR-146b-5p suppresses translation of EGFR, and binds to the EGFR 3'-UTR. Furthermore, analysis of U87-MG laser-capture microdissected cells in tumor-bearing mice indicated that expression of miR-146b-5p was inversely correlated with distance from the tumor core. These findings suggest that reconstitution of miR-146b-5p may be useful for the treatment of this invasive tumor.


Assuntos
Movimento Celular , Receptores ErbB/biossíntese , Regulação Neoplásica da Expressão Gênica/genética , Glioma/genética , MicroRNAs/genética , Animais , Western Blotting , Linhagem Celular Tumoral , Movimento Celular/genética , Receptores ErbB/genética , Expressão Gênica , Glioma/patologia , Humanos , Lasers , Camundongos , Camundongos Nus , Microdissecção , Invasividade Neoplásica/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
12.
J Cardiothorac Surg ; 15(1): 66, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32321552

RESUMO

BACKGROUND: Subxiphoid thoracoscopic thymectomy has been increasingly performed in recent years. This study aimed to assess the differences in outcomes between subxiphoid thoracoscopic thymectomy with and without chest tube drainage. METHODS: Overall, 205 subxiphoid thoracoscopic thymectomy operations were performed for myasthenia gravis, including 90 cases without and 115 cases with chest tube drainage. The clinical characteristics and perioperative outcomes of the patients were compared. RESULTS: The patients included 112 women and 93 men, with a mean age of 41 years. Two patients in the group without and 5 patient in the group with chest tube drainage developed dyspnea. In the group without chest tube, 6 patients had residual pneumothorax or pleural effusion and had a thoracentesis after surgery (6/90). In the group with chest tube, 7 patients developed delayed pleural effusion and had a thoracentesis after chest tube removal (7/115). The patients in the group without chest tube drainage group yielded lower pain scores. CONCLUSIONS: The omission of chest tube drainage may be a feasible and safe choice for patients with myasthenia gravis undergoing subxiphoid thoracoscopic thymectomy, but further prospective studies are required.


Assuntos
Tubos Torácicos , Miastenia Gravis/cirurgia , Cirurgia Torácica Vídeoassistida , Timectomia , Adolescente , Adulto , Idoso , Criança , Drenagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pneumotórax/terapia , Complicações Pós-Operatórias/terapia , Estudos Prospectivos , Estudos Retrospectivos , Adulto Jovem
13.
J Cardiothorac Surg ; 15(1): 89, 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398115

RESUMO

BACKGROUND: Compared with traditional open surgery for thymectomy, video-assisted thoracoscopic surgery (VATS) reduces hospital stay, decreases postoperative pain, and recovers faster. VATS has become increasingly popular in the past decade. VATS techniques to perform a thymectomy include subxiphoid video-assisted thoracoscopic surgery (SVATS) or lateral video-assisted thoracoscopic surgery (LVATS). In this study, our objective was to systematically review on VATS thymectomy and draw a meta-analysis on the outcomes between the two approaches. METHODS: We searched online databases and identified studies from database inception to 2019 that compared SVATS to LVATS thymectomy. Study endpoints included operative time, operative blood loss, length of hospital stay, postoperative pleural drainage, postoperative complications, conversion to open, oncologic outcomes. RESULTS: Four hundred seventy-one patients were included in this study, for which 200 and 271 patients underwent SVATS and LVATS thymectomy, respectively. Patients in the SVATS group had significantly less operative time, operative blood loss, length of hospital stay, and postoperative complications were identified. There was no statistical difference in postoperative pleural drainage, conversion to open and oncologic outcomes. No hospital deaths were recorded for either procedure. CONCLUSIONS: While randomized controlled studies are required to make definitive conclusions, this meta-analysis suggests that SVATS thymectomy is safe and can achieve good and safe operative and perioperative outcomes similar or better to LVATS thymectomy.


Assuntos
Cirurgia Torácica Vídeoassistida/métodos , Timectomia/métodos , Perda Sanguínea Cirúrgica , Humanos , Tempo de Internação , Duração da Cirurgia , Complicações Pós-Operatórias/etiologia , Cirurgia Torácica Vídeoassistida/efeitos adversos , Timectomia/efeitos adversos , Resultado do Tratamento , Processo Xifoide
14.
Adv Mater ; 32(25): e1908083, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32430920

RESUMO

Ultrasensitive and sustainable near-infrared (NIR)-emitting piezoluminescence is observed from noncentrosymmetric and ferroelectric-phase Sr3 Sn2 O7 doped with rare earth Nd3+ ions. Sr3 Sn2 O7 :Nd3+ (SSN) with polar A21 am structure is demonstrated to emit piezoluminescence of wavelength of 800-1500 nm at microstrain levels, which is enhanced by the ferroelectrically polarized charges in the multipiezo material. These discoveries provide new research opportunities to study luminescence properties of multipiezo and piezo-photonic materials, and to explore their potential as novel ultrasensitive probes for deep-imaging of stress distributions in diverse materials and structures including artificial bone and other implanted structures (in vivo, in situ, etc).

15.
Cancer Sci ; 100(9): 1597-604, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19515085

RESUMO

The metalloprotease ADAM17 (a.k.a. TACE) plays a pivotal role in the cleavage and activation of membrane-anchored receptor ligands. More recently, it has been revealed that ADAM17 is a potent sheddase of the epidermal growth factor (EGF) family of ligands and regulates epidermal growth factor receptor (EGFR) activity in a variety of tumors. EGFR is a key component of autonomous growth signaling in several tumors, and correlates with the malignancy grade of astrocytoma. In this study, we tested the hypothesis that over-expression of ADAM17 in cortical astrocytes derived from normal brain would induce a progression towards a malignant phenotype. Over-expression of human ADAM17 (hADAM17) in the CTX-TNA2 cortical astrocyte cell line resulted in non-adherent growth, increased proliferation, invasiveness, production of angiogenic factors, and expression of genes associated with immature and/or neoplastic cells. hADAM17 up-regulated EGFR and AKT phosphorylation, and increased proliferation and cell invasion were significantly dependent upon EGFR activity. When implanted in the nude mouse brain, CTX-TNA2 cells induced low histological grade, benign intraventricular gliomas. In contrast, the same astrocytes with hADAM17 formed large malignant gliomas. Taken together, these findings suggest that unregulated ADAM17 activity induces functional changes in astrocytes that significantly advance the malignant phenotype.


Assuntos
Proteínas ADAM/fisiologia , Indutores da Angiogênese/metabolismo , Astrócitos/enzimologia , Neoplasias Encefálicas/patologia , Transformação Celular Neoplásica , Regulação Neoplásica da Expressão Gênica/fisiologia , Glioma/patologia , Proteína ADAM17 , Animais , Astrócitos/patologia , Western Blotting , Neoplasias Encefálicas/etiologia , Neoplasias Encefálicas/metabolismo , Adesão Celular , Movimento Celular , Proliferação de Células , Córtex Cerebral/citologia , Ensaio de Imunoadsorção Enzimática , Receptores ErbB/metabolismo , Glioma/etiologia , Glioma/metabolismo , Humanos , Masculino , Camundongos , Camundongos Nus , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/metabolismo
16.
Lasers Med Sci ; 24(5): 777-86, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19198972

RESUMO

Photofrin photodynamic therapy (PDT) caused a dose-dependent decrease of enzymatic cell detachment by trypsin/ethylenediamine tetra-acetic acid (EDTA) in human glioma U251n and U87 cells. This happened coincidently with the increase of intracellular free calcium ([Ca(2+)](i)). Thapsigargin, which increased [Ca(2+)](i), induced further decrease in enzymatic cell detachment and increased cytotoxicity. Opposite effects were observed when 1,2-bis(2-aminophenoxy) ethane-N,N,N',N'-tetra-acetic acid tetrakis, an intracellular Ca(2+) chelator, was used. PDT-induced changes in [Ca(2+)](i) and cell detachment were not blocked by calcium channel antagonists nickel (Ni(2+)) or nimodipine, nor were they altered when cells were irradiated in a buffer free from Ca(2+) and magnesium (Mg(2+)), suggesting that [Ca(2+)](i) is derived from the internal calcium stores. Decreased cell migration was observed after PDT, as assessed by chemotactic and wound-healing assays. Our findings indicated that internal calcium store-derived [Ca(2+)](i) plays an important role in PDT-induced enzymatic cell detachment decrease and cytotoxicity. Cell migration may be affected by these changes.


Assuntos
Cálcio/metabolismo , Glioma/tratamento farmacológico , Glioma/metabolismo , Fotoquimioterapia , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Éter de Diematoporfirina/uso terapêutico , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Glioma/patologia , Humanos , Fármacos Fotossensibilizantes/uso terapêutico , Tapsigargina/farmacologia
17.
Phytochem Anal ; 20(3): 191-6, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19291674

RESUMO

INTRODUCTION: Radix asteris, with triterpenoids as its main pharmacological effective compounds, has been widely used for moistening the lung, dispersing phlegm and relieving cough. Quantification of the triterpenoids is important for the quality control of Radix asteris. OBJECTIVE: To establish a high-performance liquid chromatography method with evaporative light scattering detection for simultaneous determination of three major triterpenoids, shionone, friedelin and epi-friedelinol, in Radix asteris. METHODOLOGY: The optimal chromatographic conditions were achieved on an RP(18) column with gradient elution by acetonitrile and 0.05% acetic acid in 22 min with ELSD set at an evaporating temperature of 40 degrees C. Validation of the method included tests of linearity, sensitivity, precision, repeatability, stability and accuracy. RESULTS: All calibration curves showed good linear regression (r(2) > 0.9991) within test ranges. The established method showed good precision and accuracy with overall intra-day and inter-day variations of 1.61-2.97 and 1.74-2.42%, respectively, and overall recoveries of 97.35-101.13% for the three compounds analysed. CONCLUSION: The method developed was successfully applied to quantify the main triterpenoids in 14 Radix asteris samples.


Assuntos
Asteraceae/química , Cromatografia Líquida de Alta Pressão/métodos , Triterpenos/análise , Luz , Reprodutibilidade dos Testes , Espalhamento de Radiação , Sensibilidade e Especificidade , Espectrofotometria Ultravioleta
18.
Materials (Basel) ; 12(13)2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31277205

RESUMO

The temperature-dependent dynamics of the hydrogen/deuterium atoms in geometrically frustrated magnets Co2(OH)3Br and its deuterated form Co2(OD)3Br were investigated by muon spin relaxation (µSR). The deuterium atoms in Co2(OD)3Br were found to be rapidly fluctuating at high temperatures, which should be arising as a quantum atomic effect due to the small mass of deuterium, then they drastically slowed down toward Tc = 250 K where a broad anomaly appeared in the dielectric response, and finally became quasi-static at around 180 K. Meanwhile, the hydrogen atoms in Co2(OH)3Br also exhibited a two-step slowing at ~240 K and ~180 K, respectively. The revealed properties in Co2(OH)3Br/Co2(OD)3Br are reminiscent of relaxor-type ferroelectrics. The present study suggested the effectiveness of the µSR technique on revealing the hydrogen/deuterium (H/D) dynamics in Co2(OH)3Br/Co2(OD)3Br. Furthermore, magnetic coupling was found to be existing at high temperatures in this system. This work provides clear evidence to the mechanism of ferroelectric responses in the hydroxyl salts, i.e., the slowing of protons (deuterium ions) is directly related to the newly revealed ferroelectricity.

19.
Neurobiol Dis ; 32(2): 273-80, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18778774

RESUMO

We investigated the treatment of experimental autoimmune encephalomyelitis (EAE) in mice with Niaspan, an agent used to elevate high-density lipoprotein (HDL). EAE mice were treated with Niaspan starting on the immunization or clinical onset day. Neurological functional recovery was significantly increased in the Niaspan treated mice (100 mg/kgbw) compared to the controls. Inflammatory infiltrates were significantly reduced in the Niaspan treatment group compared to the EAE controls. HDL level, intact myelin area, newly formed oligodendrocytes, regenerating axons, gene and protein levels of sonic hedgehog (Shh)/Gli1 were significantly increased in the Niaspan treated mice compared to EAE controls. These data indicate that Niaspan treatment improved functional recovery after EAE, possibly, via reducing inflammatory infiltrates and demyelination areas, and stimulating oligodendrogenesis and axonal regeneration. Niaspan-mediated activation of Shh/Gli1 pathway may promote functional recovery post-EAE.


Assuntos
Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/fisiopatologia , Niacina/uso terapêutico , Recuperação de Função Fisiológica/efeitos dos fármacos , Complexo Vitamínico B/uso terapêutico , Animais , Linhagem Celular Transformada , Proliferação de Células/efeitos dos fármacos , HDL-Colesterol/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Encefalomielite Autoimune Experimental/induzido quimicamente , Encefalomielite Autoimune Experimental/metabolismo , Feminino , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Camundongos , Proteína Proteolipídica de Mielina/efeitos adversos , Regeneração Nervosa/efeitos dos fármacos , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/metabolismo , Transdução de Sinais/efeitos dos fármacos , Medula Espinal/efeitos dos fármacos , Medula Espinal/patologia , Medula Espinal/fisiopatologia , Fatores de Tempo
20.
J Neurosci Res ; 86(7): 1501-10, 2008 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-18214988

RESUMO

Oligodendrocyte (OLG) damage leads to demyelination, which is frequently observed in ischemic cerebrovascular diseases. In this study, we investigated the effect of bone marrow stromal cells (BMSCs) on OLGs subjected to oxygen-glucose deprivation (OGD). N20.1 cells (mouse OLG cell line) were transferred into an anaerobic chamber for 3 hr in glucose-free and serum-free medium. After OGD incubation, OLG cultures were divided into the following groups: 1) OGD alone, 2) OLG cocultured with BMSCs, 3) treatment with the phosphoinostide 3-kinase (PI3k) inhibitor LY294002, 4) LY294002-treated OLGs with BMSC cocultured, and 5) anti-p75 antibody-treated OLGs. After an additional 3 hr of reoxygenation incubation, OLG viability and apoptosis were measured. The mRNA expression in the BMSCs and OLGs was analyzed using quantitative real-time PCR (RT-PCR). Serine/threonine-specific protein kinase (Akt), phosphorylated Akt (p-Akt), p75, and caspase 3 protein expressions in OLGs were measured by Western blot. Our results suggest that BMSCs produce growth factors, activate the Akt pathway, and increase the survival of OLGs. BMSCs also reduce p75 and caspase 3 expressions in the OGD-OLGs, which leads to decreased OLG apoptosis. BMSCs participate in OLG protection that may occur with promoting growth factors/PI3K/Akt and inhibiting the p75/caspase pathways. Our study provides insight into white matter damage and the therapeutic benefits of BMSC-based remyelinating therapy after stroke and demyelinating diseases.


Assuntos
Células da Medula Óssea/fisiologia , Glucose/deficiência , Hipóxia/prevenção & controle , Oligodendroglia/fisiologia , Células Estromais/fisiologia , Análise de Variância , Animais , Apoptose , Sobrevivência Celular , Células Cultivadas , Cromonas/farmacologia , Técnicas de Cocultura , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Marcação In Situ das Extremidades Cortadas/métodos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Morfolinas/farmacologia , Receptores de Fatores de Crescimento/genética , Receptores de Fatores de Crescimento/metabolismo
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