الملخص
Glioma is a primary brain tumor with high incidence rate. High-grade gliomas (HGG) are those with the highest degree of malignancy and the lowest degree of survival. Surgical resection and postoperative adjuvant chemoradiotherapy are often used in clinical treatment, so accurate segmentation of tumor-related areas is of great significance for the treatment of patients. In order to improve the segmentation accuracy of HGG, this paper proposes a multi-modal glioma semantic segmentation network with multi-scale feature extraction and multi-attention fusion mechanism. The main contributions are, (1) Multi-scale residual structures were used to extract features from multi-modal gliomas magnetic resonance imaging (MRI); (2) Two types of attention modules were used for features aggregating in channel and spatial; (3) In order to improve the segmentation performance of the whole network, the branch classifier was constructed using ensemble learning strategy to adjust and correct the classification results of the backbone classifier. The experimental results showed that the Dice coefficient values of the proposed segmentation method in this article were 0.909 7, 0.877 3 and 0.839 6 for whole tumor, tumor core and enhanced tumor respectively, and the segmentation results had good boundary continuity in the three-dimensional direction. Therefore, the proposed semantic segmentation network has good segmentation performance for high-grade gliomas lesions.
الموضوعات
Humans , Attention , Glioma/diagnostic imaging , Magnetic Resonance Imaging/methods , Semanticsالملخص
With the rapid development of network structure, convolutional neural networks (CNN) consolidated its position as a leading machine learning tool in the field of image analysis. Therefore, semantic segmentation based on CNN has also become a key high-level task in medical image understanding. This paper reviews the research progress on CNN-based semantic segmentation in the field of medical image. A variety of classical semantic segmentation methods are reviewed, whose contributions and significance are highlighted. On this basis, their applications in the segmentation of some major physiological and pathological anatomical structures are further summarized and discussed. Finally, the open challenges and potential development direction of semantic segmentation based on CNN in the area of medical image are discussed.
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Objective To evaluate the role of peroxisome proliferator-activated receptor gamma (PPARγ) in exogenous protectin D1 ( PD1)-induced reduction of endotoxin-induced acute lung injury (ALI) in mice. Methods Thirty-two clean-grade healthy male BABL∕C mice, weighing 20-25 g, aged 6-8 weeks, were divided into 4 groups (n=8 each) using a random number table method: sham operation group (group S), ALI group, PD1 group and PPARγ antagonist GW9662 group. Mice underwent oral tra-cheal intubation, normal saline was instilled, and 1 h later normal saline was injected via the tail vein in group S. Mice underwent oral tracheal intubation, lipopolysaccharide (LPS) 3 mg∕kg was instilled, and 1 h later normal saline was injected via the tail vein in group ALI. Mice underwent oral tracheal intubation, LPS 3 mg∕kg was instilled, and 1 h later PD1 200 ng was injected via the tail vein in group PD1. Mice un-derwent oral tracheal intubation, LPS 3 mg∕kg was instilled, and 1 h later GW9662 1 mg∕kg and PD1 200 ng were injected via the tail vein in group GW9662. Mice were sacrificed at 24 h after intratracheal instilla-tion of LPS, the left lung was lavaged with phosphate buffer solution, and the broncho-alveolar lavage fluid (BALF) was collected for determination of neutrophil count and concentrations of interleukin-1beta ( IL-1β), tumor necrosis factor-alpha ( TNF-α) and IL-6 ( by enzyme-linked immunosorbent assay). Right lung tissues were obtained and cut into sections which were stained with haematoxylin and eosin and exam-ined with a light microscope for microscopic examination of the pathological changes which were scored (lung injury score) and for determination of the expression of PPARγ in lung tissues. Results Compared with group S, the neutrophil counts in BALF, concentrations of IL-1β, TNF-α and IL-6 and lung injury score were significantly increased, and the expression of PPARγ was down-regulated in group ALI ( P<0. 01). Compared with group ALI, the neutrophil counts in BALF, concentrations of IL-1β, TNF-α and IL-6 and lung injury score were significantly decreased, and the expression of PPARγ was up-regulated in group PD1 (P<0. 01). Compared with group PD1, the neutrophil counts in BALF, concentrations of IL-1β, TNF-α and IL-6 and lung injury score were significantly increased, and the expression of PPARγ was down-regulated in group GW9662 ( P<0. 01). Conclusion PPARγ activation is involved in exogenous protectin D1-induced reduction of LPS-induced ALI in mice.
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Objective@#To investigate the association between single nucleotide polymorphisms (SNPs) of rs3130542 and rs4821116 in the HLA-C and UBE2L3 genes and the effect of telbivudine antiviral therapy during pregnancy in HBeAg-positive mothers through a large-sample control study, and to provide a basis for the development of individualized blocking strategies for pregnant women with a high viral load.@*Methods@#The genotypes of rs3130542 and rs4821116 were determined for 312 pregnant women with a high viral load who received telbivudine antiviral therapy during the second or third trimester of pregnancy, and the dominant model, recessive model, and additive model were used to analyze the association between the genotypes of these two loci and the reduction in HBV DNA load. The Shapiro-Wilk test and the Levene test were used to evaluate data normality and homogeneity of variances, and the t-test or the non-parametric Mann-Whitney U test was selected based on data type and was used for the comparison of means between groups. The Hardy-Weinberg equilibrium was used to determine the genotype of SNPs, and the dominant model, recessive model, and additive model were used for analysis.@*Results@#Mothers with an AA/AG genotype of rs3130542 in the HLA-C gene had a significantly higher probability of HBV DNA load ≥103 IU/ml at the time of delivery (P < 0.05) and a significantly higher risk of failure in the prevention of mother-to-child transmission, no matter whether they started to take telbivudine at week 24 or 28 of pregnancy. The association between the genotype of rs4821116 in the UBE2L3 gene and the reduction in viral load in pregnant women needed to be confirmed by studies with a larger sample size.@*Conclusion@#Pregnant women with a high viral load and an AA/AG genotype of rs3130542 in the HLA-C gene tend to have poor response to antiviral therapy during pregnancy, and early antiviral intervention is recommended for such patients.
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Objective To investigate the role of glucose-regulated protein 78 (GRP78) in sevoflurane preconditioning-induced inhibition of apoptosis in cardiomyocytes of rats.Methods The cultured cardiomyocytes of Sprague-Dawley rats were randomly divided into 5 groups (n =30 each) using a random number table:control group (group C),hypoxia-reoxgenation (H/R) group,sevoflurane preconditioning group (group S),siRNA-GRP78 group and siRNA control group.H/R was produced by 2 h exposure of cells to 95% N2-5% CO2 in an air-tight chamber at 37 ℃,followed by reoxygenation with 95% O2-5% CO2 in an air-tight chamber at 37 ℃ for 1 h.In group S,the cells were incubated with 2.5% sevoflurane for 20 min,followed by 10-min washout before H/R.In siRNA-GRP78 group,the cells were transfected with siRNA-GRP78 100 nmol/L,and 24 h later preconditioning with sevoflurane was performed and H/R was produced.In siRNA group,cells were transfected with siRNA,and the other treatments were similar to those previously described in siRNA-GRP78 group.After treatment in each group,the expression of GRP78 in myocardial cells and cytochrome c in cytoplasm and mitochondria was detected by Western blot.Lactic dehydrogenase (LDH) and creatine kinase (CK) activities in the culture medium of each group were determined by ELISA.The apoptosis in myocardial cells was assessed by flow cytometry.Apoptotic rate was calculated.Intracellular free Ca2+ concentration ([Ca2+]i) was measured with the fluorescent probe Fura-2/ AM.The opening of mPTP was measured by fluorescence spectrophotometry.Results Compared to group C,the expression of GRP78 in myocardial cells and cytochrome c in cytoplasm was significantly up-regulated,LDH and CK activities in the culture medium,apoptotic rate and [Ca2+]i were increased,and the expression of cytochrome c in mitochondria was down-regulated in H/R group.Compared to group H/R,the expression of GRP78 in myocardial cells and cytochrome c in mitochondria was significantly up-regulated,LDH and CK activities in the culture medium,apoptotic rate,[Ca2+] i and opening of mPTP were decreased,and the expression of cytochrome c in cytoplasm was down-regulated in group S,and no significant change was found in the parameters mentioned above in siRNA group.Compared to group S,the expression of GRP78 in myocardial cells and cytochrome c in mitochondria was significantly down-regulated,LDH and CK activities in the culture medium,apoptotic rate,[Ca2+] i and opening of mPTP were increased,and the expression of cytochrome c in cytoplasm was up-regulated in group siRNA-GRP78.Conclusion GRP78 is involved in sevoflurane preconditioning-induced inhibition of apoptosis in cardiomyocytes of rats,and the mechanism is related to maintenance of intracellular Ca2+ stability and inhibition of opening of mPTP.
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Objective To compare the noxious stimulations induced by insertion of Proseai laryngeal mask airway(PLMA)and classic laryngeal mask airway(CLMA)in children.Methods Forty-seven ASA Ⅰ or Ⅱ children,aged 3-12 yr and undergoing surgery under general anesthesia,were randomly divided into 2 groups:PLMA group(group P,n =23)and CLMA group(group C,n =24).General anesthesia was induced with target-controlled infusion(TCI)of propofol.When the effect-site concentration of propofol was equal to the plasma concentration predetermined.PLMA or CLMA insertion was attempted.The target plasma concentration of propofol was predetermined according to Dixon's up-down method,with 0.2 μg/ml as a step size.The initial target plasma concentration of propofol was 6 μg/ml and 4.4 μg/ml for groups P and C,respectively.The preedetermined target plasma concentration of propofol and the satisfaction of insertion conditions for each child were recorded.Results The 50% effective concentration(EC50)of propofol to achieve satisfied condition of PLMA and CLMA insertion were 5.87(95% CI,5.62-6.11)and 4.53(95% C1,4.38-4.69)μg/nl,respectively,and the difference was significant(P < 0.01).Conclusion The noxious stimulation induced by insertion of PLMA in children aged 3-12 years is stronger than that of CLMA.