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1.
Sensors (Basel) ; 22(9)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35591069

RESUMO

The average error rate in liver cirrhosis classification on B-mode ultrasound images using the traditional pattern recognition approach is still too high. In order to improve the liver cirrhosis classification performance, image correction methods and a convolution neural network (CNN) approach are focused on. The impact of image correction methods on region of interest (ROI) images that are input into the CNN for the purpose of classifying liver cirrhosis based on data from B-mode ultrasound images is investigated. In this paper, image correction methods based on tone curves are developed. The experimental results show positive benefits from the image correction methods by improving the image quality of ROI images. By enhancing the image contrast of ROI images, the image quality improves and thus the generalization ability of the CNN also improves.


Assuntos
Processamento de Imagem Assistida por Computador , Cirrose Hepática , Humanos , Processamento de Imagem Assistida por Computador/métodos , Cirrose Hepática/diagnóstico por imagem , Redes Neurais de Computação , Ultrassonografia
2.
Biochem Biophys Res Commun ; 372(1): 19-23, 2008 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-18468515

RESUMO

Pirfenidone (PFD) is focused on a new anti-fibrotic drug, which can minimize lung fibrosis etc. We evaluated the superoxide (O2*-) scavenging activities of PFD and the PFD-iron complex by electron spin resonance (ESR) spectroscopy, luminol-dependent chemiluminescence assay, and cytochrome c reduction assay. Firstly, we confirmed that the PFD-iron complex was formed by mixing iron chloride with threefold molar PFD, and the complex was stable in distilled water and ethanol. Secondary, the PFD-iron complex reduced the amount of O2*- produced by xanthine oxidase/hypoxanthine without inhibiting the enzyme activity. Thirdly, it also reduced the amount of O2*- released from phorbor ester-stimulated human neutrophils. PFD alone showed few such effects. These results suggest the possibility that the O2*- scavenging effect of the PFD-iron complex contributes to the anti-fibrotic action of PFD used for treating idiopathic pulmonary fibrosis.


Assuntos
Sequestradores de Radicais Livres/farmacologia , Piridonas/farmacologia , Superóxidos/metabolismo , Linhagem Celular , Sequestradores de Radicais Livres/síntese química , Sequestradores de Radicais Livres/uso terapêutico , Humanos , Ferro , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Fibrose Pulmonar/tratamento farmacológico , Piridonas/química , Piridonas/uso terapêutico , Superóxidos/química
3.
Biochem Biophys Res Commun ; 370(1): 93-7, 2008 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-18355451

RESUMO

Electron spin resonance using spin-trapping is a useful technique for detecting direct reactive oxygen species, such as superoxide (O2.-). However, the widely used spin trap 2,2-dimethyl-3,4-dihydro-2H-pyrrole N-oxide (DMPO) has several fundamental limitations in terms of half-life and stability. Recently, the new spin trap 2-diphenylphosphinoyl-2-methyl-3,4-dihydro-2H-pyrrole N-oxide (DPhPMPO) was developed by us. We evaluated the biological applicability of DPhPMPO to analyze O2.- in both cell-free and cellular systems. DPhPMPO had a larger rate constant for O2.- and formed more stable spin adducts for O2.- than DMPO in the xanthine/xanthine oxidase (X/XO) system. In the phorbol myristate acetate-activated neutrophil system, the detection potential of DPhPMPO for O2.- was significantly higher than that of DMPO (k(DMPO)=13.95M(-1)s(-1), k(DPhPMPO)=42.4M(-1)s(-1)). These results indicated that DPhPMPO is a potentially good candidate for trapping O2.- in a biological system.


Assuntos
Óxidos N-Cíclicos/química , Espectroscopia de Ressonância de Spin Eletrônica , Pirróis/química , Marcadores de Spin , Detecção de Spin , Superóxidos/análise , Linhagem Celular , Sistema Livre de Células/química , Humanos , Cinética , Neutrófilos/química , Neutrófilos/efeitos dos fármacos , Superóxidos/química , Acetato de Tetradecanoilforbol/farmacologia , Xantina/química , Xantina Oxidase/química
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