Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 14(7): e0219483, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31318905

RESUMO

Hypoxia is an important cause of acute kidney injury (AKI) in various conditions because kidneys are one of the most susceptible organs to hypoxia. In this study, we investigated whether nicotinamide adenine dinucleotide 3-phosphate (NADPH) oxidase 4 (Nox4) plays a role in hypoxia induced AKI in a cellular and animal model. Expression of Nox4 in cultured human renal proximal tubular epithelial cells (HK-2) was significantly increased by hypoxic stimulation. TGF-ß1 was endogenously secreted by hypoxic HK-2 cells. SB4315432 (a TGF-ß1 receptor I inhibitor) significantly inhibited Nox4 expression in HK-2 cells through the Smad-dependent cell signaling pathway. Silencing of Nox4 using Nox4 siRNA and pharmacologic inhibition with GKT137831 (a specific Nox1/4 inhibitor) reduced the production of ROS and attenuated the apoptotic pathway. In addition, knockdown of Nox4 increased cell survival in hypoxic HK-2 cells and pretreatment with GKT137831 reproduce these results. This study demonstrates that hypoxia induces HK-2 cell apoptosis through a signaling pathway involving TGF-ß1 via Smad pathway induction of Nox4-dependent ROS generation. In an ischemia/reperfusion rat model, pretreatment of GKT137831 attenuated ischemia/reperfusion induced acute kidney injury as indicated by preserved kidney function, attenuated renal structural damage and reduced apoptotic cells. Therapies targeting Nox4 may be effective against hypoxia-induced AKI.


Assuntos
Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , NADPH Oxidase 4/metabolismo , Transdução de Sinais , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Injúria Renal Aguda/fisiopatologia , Animais , Apoptose/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Testes de Função Renal , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Modelos Biológicos , NADPH Oxidase 4/antagonistas & inibidores , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Pirazóis/farmacologia , Pirazolonas , Piridinas/farmacologia , Piridonas , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Fator de Crescimento Transformador beta1/farmacologia
2.
Appl Radiat Isot ; 131: 23-29, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29100155

RESUMO

A self-shielding device for the synthesis of radiopharmaceuticals was developed and fabricated in this study. Radiation exposure was minimized by the self-shielding of the kit, installation of the disposable kit in the auxiliary chamber while in a shielded state, and discharge of the kit into a radioactive waste container upon completion of the synthesis process. The developed self-shielding synthesis kit was tested by synthesizing 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) in order to verify its performance.


Assuntos
Fluordesoxiglucose F18/síntese química , Exposição à Radiação/prevenção & controle , Proteção Radiológica/instrumentação , Proteção Radiológica/métodos , Compostos Radiofarmacêuticos/síntese química , Desenho de Equipamento , Resíduos Radioativos , Radioquímica
3.
Rev Sci Instrum ; 88(3): 034706, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28372372

RESUMO

We design a stripline-type Wilkinson power divider and combiner for a 3.2 kW solid-state radio frequency (RF) amplifier module and optimize this setup. A Teflon-based printed circuit board is used in the power combiner to transmit high RF power efficiently in the limited space. The reflection coefficient (S11) and insertion loss (S21) related to impedance matching are characterized to determine the optimization process. The resulting two-way divider reflection coefficient and insertion loss were -48.00 dB and -3.22 dB, respectively. The two-way power combiner reflection coefficient and insertion loss were -20 dB and -3.3 dB, respectively. Moreover, the 3.2 kW solid-state RF power test results demonstrate that the proposed power divider and combiner exhibit a maximum efficiency value of 71.3% (combiner loss 5%) at 48 V supply voltage.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA