Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Talanta ; 235: 122719, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517587

RESUMO

Here, a dual lock-and-key fluorescence probe was developed for visualizing the inflammatory process in myocardial H9C2 cells. The probe possessed two-photon properties, viscosity sensitivity, and hydrogen peroxide (H2O2) responsiveness. A thiocarbamate spacer between fluorophore and H2O2 responsive unit enabled the release of carbonyl sulfide (COS). This rapidly converts to the anti-inflammatory hydrogen sulfide (H2S) by the ubiquitous enzyme carbon anhydrase. The probe displayed a dual response towards hydrogen peroxide and viscosity in vitro. No obvious fluorescence changes were observed towards either hydrogen peroxide or viscosity alone. In cellular experiments, the probe demonstrated good biocompatibility, low toxicity, and was shown responses towards exogenous and endogenous hydrogen peroxide under viscosity conditions. LPS induced cell inflammation showed it was able to effectively alleviate the inflammation-caused damage by releasing H2S and eliminating H2O2. The new protocol demonstrates its promising to achieve diagnosis and treatment of cellular inflammatory process.


Assuntos
Corantes Fluorescentes , Sulfeto de Hidrogênio , Fluorescência , Células HeLa , Humanos , Peróxido de Hidrogênio , Inflamação/tratamento farmacológico , Viscosidade
2.
Biosci Rep ; 40(6)2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32441737

RESUMO

BACKGROUND: The present study was designed to explore the regulatory mechanisms and influences of cotinine on deep vein thrombosis (DVT) in rats via the toll-like receptor 4/nuclear factor κ binding (TLR-4/NF-κB) pathway. METHODS: In this experimental study, 30 SD rats were randomly assigned to control group, sham operation group, model group, cotinine (10 µg/kg) group, and model + cotinine (10 µg/kg) group. The thromboxane B2 (TXB2), 6-keto-PGF1α, plasminogen activator inhibitor (PAI), tissue plasminogen activator (t-PA), TLR4, NF-κB, and p65 mRNA and protein expression and tissue changes were analyzed by ELISA, Hematoxylin-Eosin (HE) staining, RT-PCR, and Western blot. RESULTS: There was no significant difference between the control and sham operation groups (P>0.05). The model and cotinine groups showed significantly higher mRNA and protein levels of TXB2, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), PAI, TLR-4, and NF-κB, and significantly lower levels of 6-keto-PGF1α and t-PA than the control and sham operation groups (P<0.05), and the model + cotinine group showed significantly higher mRNA and protein levels of TXB2, IL-6 and TNF-α, PAI, TLR-4, and NF-κB and significantly lower levels of 6-keto-PGF1α and t-PA than the model group (P<0.05). CONCLUSION: Cotinine can aggravate thrombus and inflammation in rats with DVT, and the mechanism may be associated with the activation of the TLR-4/NF-κB inflammatory signaling pathway.


Assuntos
Anti-Inflamatórios/farmacologia , Cotinina/farmacologia , Fibrinolíticos/farmacologia , NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismo , Trombose Venosa/tratamento farmacológico , 6-Cetoprostaglandina F1 alfa/sangue , Animais , Modelos Animais de Doenças , Masculino , NF-kappa B/genética , Ratos Sprague-Dawley , Transdução de Sinais , Tromboxano B2/sangue , Receptor 4 Toll-Like/genética , Trombose Venosa/genética , Trombose Venosa/metabolismo
3.
Chin J Traumatol ; 23(1): 25-28, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32057562

RESUMO

PURPOSE: To explore the significance of traditional vascular reconstruction and covered stent for limb salvage after subclavian artery injury. METHODS: Patients with subclavian artery injury admitted to Beijing Jishuitan Hospital from January 2010 to December 2018 were retrospectively analyzed. All the injuries have been confirmed by intraoperative exploration, computed tomography angiography or digital subtraction angiography. Complete or partial amputation injuries were excluded. Mild artery defect or partial intimal damage was treated by interventional implantation, while other patients received open surgeries, including direct suture of small defect less than 2 cm and transplantation with autologous vein or artificial blood when the defect was more than 2 cm. Patients were divided into open surgery group and stent implantation group based on the treatment they received. Patients were followed up at 2 weeks (first stage) and 6 months (second stage) after operation to investigate limb salvage. Student's t-test was used to compare the general data between two groups and Chi-square test to analyze the rate of limb salvage. RESULTS: Altogether 50 cases of subclavian artery injury were treated, including 36 cases of open surgery and 14 cases of stent implantation. Combination of nerve injury was observed in 27 cases (75.0%) in open surgery group and 12 cases (85.7%) in stent implantation group. Amputation developed in 3 cases with open surgery and 1 case with stent implantation. Consequently the rate of successful limb salvage was respectively 91.7% (33/36) and 92.9% (13/14), revealing no significant difference (p > 0.05). CONCLUSION: Rapid reconstruction of blood circulation is crucial following subclavian artery injury, no matter what kinds of treatment strategies have been adopted. Interventional stent implantation can achieve a good effect for limb salvage.


Assuntos
Procedimentos Cirúrgicos Reconstrutivos/métodos , Stents , Artéria Subclávia/lesões , Artéria Subclávia/cirurgia , Procedimentos Cirúrgicos Vasculares/métodos , Adolescente , Adulto , Angiografia por Tomografia Computadorizada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Subclávia/diagnóstico por imagem , Adulto Jovem
4.
J Biol Chem ; 293(14): 5335-5344, 2018 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-29462785

RESUMO

The Wnt/ß-catenin pathway is essential for embryonic development and homeostasis, but excessive activation of this pathway is frequently observed in various human diseases, including cancer. Current therapeutic drugs targeting the Wnt pathway often lack sufficient efficacy, and new compounds targeting this pathway are therefore greatly needed. Here we report that the plant-derived natural product parthenolide (PTL), a sesquiterpene lactone, inhibits Wnt signaling. We found that PTL dose-dependently inhibits Wnt3a- and CHIR99021-induced transcriptional activity assessed with the T-cell factor (TCF)/lymphoid enhancer factor (LEF) firefly luciferase (TOPFlash) assay in HEK293 cells. Further investigations revealed that PTL decreases the levels of the transcription factors TCF4/LEF1 without affecting ß-catenin stability or subcellular distribution. Moreover, this effect of PTL on TCF4/LEF1 was related to protein synthesis rather than to proteasome-mediated degradation. Of note, siRNA-mediated knockdown of RPL10, a ribosome protein PTL binds, substantially decreased TCF4/LEF1 protein levels and also Wnt3a-induced TOPFlash activities, suggesting a potential mechanism by which PTL may repress Wnt/ß-catenin signaling. In summary, PTL binds RPL10 and thereby potently inhibits the Wnt/ß-catenin pathway.


Assuntos
Lactonas/farmacologia , Sesquiterpenos/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , Linhagem Celular Tumoral , Células HEK293 , Humanos , Lactonas/metabolismo , Fator 1 de Ligação ao Facilitador Linfoide/efeitos dos fármacos , Fator 1 de Ligação ao Facilitador Linfoide/genética , Regiões Promotoras Genéticas/genética , Proteína Ribossômica L10 , Proteínas Ribossômicas/efeitos dos fármacos , Proteínas Ribossômicas/metabolismo , Sesquiterpenos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição 4/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Ativação Transcricional/genética , beta Catenina/efeitos dos fármacos
5.
Health Phys ; 113(5): 387-391, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28961587

RESUMO

Effective determination for enrichment of the uranium materials in heavy shielding is technically difficult to solve. Various technical methods so far have been proposed to deal with this problem. With the time-correlated coincidence measurement method, 14 MeV neutrons and fission spectrum neutrons are chosen to interrogate the uranium samples with different masses and enrichments. The fission spectrum neutrons are obtained by slowing down the 14 MeV neutrons. Results have shown that a good linear relationship exists between masses of the uranium materials (≤10% enriched U) that possess the same enrichment. A linear relationship also exists between enrichments of the uranium materials that possess the same mass.


Assuntos
Urânio/química , Deutério/química , Nêutrons , Radioquímica , Fatores de Tempo
6.
Health Phys ; 112(3): 276-281, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28121728

RESUMO

For Cs and Co gamma ray spectra, gamma ray energy is proportional to the amplitude of the pulse signal, and energy resolution can be improved by pulse signal processing with mathematical algorithms. Influenced by system measurement noise and baseline fluctuation, the pulse amplitude is difficult to calculate accurately. A method that combines the Kalman filter baseline estimation with the non-linear exponential fitting has been used. By this method, the pulse signal is divided into two parts: one is the raising edge before the pulse peak, and another is after the pulse peak. The pulse amplitude equals the difference between the pulse starting height and the pulse peak height. The pulse starting height is obtained by Kalman filter baseline estimation on the rising edge of the pulse starting point. The pulse peak height is calculated by nonlinear exponential fitting on the falling edge of the pulse highest point. When the sampling rate is 100 MHz, the pulse signals obtained from a Cd(Zn)Te detector are analyzed by this method. Results have shown that the processed pulses have a more distinguishable amplitude distribution; energy resolution for the Cs spectrum is approximately 2.97% at 662 keV (~19.66 keV FWHM), and for the Co spectrum it is 2.61% at 1,332 keV (~34.76 keV FWHM).


Assuntos
Algoritmos , Radioisótopos de Césio/análise , Radioisótopos de Cobre/análise , Raios gama , Modelos Estatísticos , Processamento de Sinais Assistido por Computador , Simulação por Computador , Dinâmica não Linear , Análise Numérica Assistida por Computador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria gama
7.
Health Phys ; 111(1): 17-21, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27218290

RESUMO

Delayed gamma spectrum is the fingerprint of uranium materials in arms control verification technology. The decay chain is simplified into basic state linear chain and excitation state linear chain to calculate and analyze the delayed gamma spectra of fission products. Formulas of the changing rule for nuclide number before and after zero-time are deduced. The C program for calculating the delayed gamma ray spectra data is constructed, and related experiments are conducted to verify this theory. Through analysis of the delayed gamma counts of several nuclides, the calculated results are found to be consistent with experimental values.


Assuntos
Algoritmos , Teste de Materiais/métodos , Fissão Nuclear , Radiometria/métodos , Software , Urânio/análise , Urânio/química , Meia-Vida , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Urânio/efeitos da radiação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...