1.Imaging and clinical features of diaphragm dysfunction after cardiac sternotomy.
Xinyuan ZHU ; Dawei WU ; Hao ZHANG ; Chen LIN ; Hongyan ZHAI
Chinese Critical Care Medicine 2025;37(7):657-663
OBJECTIVE:
To analyze the imaging and clinical features of diaphragm dysfunction in patients who underwent selective cardiac sternotomy with diaphragm ultrasound and chest CT.
METHODS:
A prospective cohort study was conducted. The patients undergoing selective cardiac sternotomy in the cardiac and vascular surgery department of Tianjin Medical University General Hospital from June to September 2023 were enrolled. Bedside ultrasound was performed on the day before surgery, within 24 hours of extubation, and on the 7th day after surgery to measure diaphragm excursion (DE) and diaphragm thickness (DT), and to calculate the diaphragm thickening fraction (DTF). The distance from the diaphragm's apex to the thorax's apex in the chest CT scout view was measured before and after the operation, and the diaphragm elevating fraction (DEF) was calculated. Patients were divided into two groups based on whether diaphragm dysfunction (DE < 1 cm) occurred on the 7th day after surgery. The change patterns of imaging indicators were analyzed in both groups. The clinical data of both groups before, during, and after surgery were compared.
RESULTS:
In total, 67 patients who underwent cardiac sternotomy were enrolled. Among them, 24 patients developed diaphragm dysfunction within 24 hours after extubation; on the 7th day after surgery, 19 patients (28.4%) still exhibited diaphragm dysfunction, while 48 patients (71.6%) did not. Ultrasonic examination of the diaphragm revealed that, compared with the non-diaphragm dysfunction group, patients in the diaphragm dysfunction group exhibited varying degrees of decrease in DE and DTF before and after surgery, with a more significant decrease on the left side, and the differences were statistically significant on the 7th day after surgery [DE (cm): 1.06±0.77 vs. 1.59±0.63, DTF: 19.3% (14.8%, 21.1%) vs. 21.3% (18.3%, 26.1%), both P < 0.05]. There was no statistically significant difference in DT between the two groups at each time point. Changes in bilateral DE and DTF revealed that the non-diaphragm dysfunction group experienced early transient postoperative weakening of diaphragm function, followed by rapid recovery to the preoperative level on the 7th day after surgery, unlike the diaphragm dysfunction group. There were no significant differences between bilateral DE in the two groups on the day before surgery, and the left DE was significantly lower than the right DE within 24 hours after extubation and on the 7th day after surgery in the diaphragm dysfunction group (cm: 0.93±0.72 vs. 1.45±0.70 within 24 hours after extubation, 1.06±0.77 vs. 1.70±0.92 on the 7th day after surgery, both P < 0.05) but no significant difference was found in bilateral DT or DTF. The chest CT scan showed that, the incidence of postoperative diaphragm elevation was 61.2% (41/67), and 38.8% (26/67) did not, while no statistically significant difference in DEF was found between the two groups, nor within each group on both sides. Analysis of the clinical data showed a higher proportion of atrial fibrillation and pulmonary hypertension before surgery [atrial fibrillation: 36.8% (7/19) vs. 10.4% (5/48), pulmonary hypertension: 15.8% (3/19) vs. 2.1% (1/48), both P < 0.05], a higher incidence of high-flow oxygenation and pneumonia during surgery [high-flow oxygenation: 52.6% (10/19) vs. 25.0% (12/48), pneumonia: 73.7% (14/19) vs. 45.8% (22/48), both P < 0.05], and a longer duration of mechanical ventilation and length of intensive care unit (ICU) stay [duration of mechanical ventilation (hours): 47.0 (38.0, 73.0) vs. 24.5 (20.0, 48.0), length of ICU stay (hours): 69.0 (65.0, 117.5) vs. 60.0 (42.3, 90.6), both P < 0.05] in the diaphragm dysfunction group as compared with those in the non-diaphragm dysfunction group.
CONCLUSIONS
There was a high incidence of diaphragm dysfunction after cardiac sternotomy, which reflected the early transient postoperative weakening of diaphragm function, followed by rapid recovery to the preoperative level in most patients, predominantly on the left side. Diaphragm dysfunction, which was associated with atrial fibrillation and pulmonary hypertension significantly increased the incidence of postoperative pneumonia and prolonged the duration of mechanical ventilation and length of ICU stay.
Humans
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Diaphragm/physiopathology*
;
Prospective Studies
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Sternotomy/adverse effects*
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Ultrasonography
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Postoperative Complications/diagnostic imaging*
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Tomography, X-Ray Computed
;
Male
;
Female
;
Middle Aged
;
Aged
;
Cardiac Surgical Procedures/adverse effects*
2.Expression and clinical significance of FAT1 gene in pancreatic adenocarcinoma
Xinyuan LIU ; Ying YANG ; Chaodan YANG ; Zhengxiao MA ; Conghui WU ; Chen XU ; Rui ZHU ; Pan LIU ; Lisha YING ; Wenjuan YIN ; Dan SU
Chinese Journal of Oncology 2024;46(11):1029-1037
Objective:To analyze the expression of FAT1 gene in pancreatic adenocarcinoma and its relationship with clinicopathological features, prognosis, and immunotherapy for pancreatic adenocarcinoma.Methods:(1) Bioinformatics analysis: based on FAT1 mRNA expression and clinical data of 179 cases of pancreatic adenocarcinoma in the TCGA database, and FAT1 mRNA expression data of 328 cases of normal pancreatic tissues in the GTEx database. We analyzed the differences in FAT1 mRNA expression in pancreatic adenocarcinoma and normal pancreatic tissues and the relationship between FAT1 mRNA expression and the degree of differentiation, clinical stage, prognosis, immune cell infiltration, and immune checkpoint-associated genes in pancreatic adenocarcinoma. FAT1-related differentially expressed genes were analyzed by applying Limma 3.40.2 software package, and GO and KEGG enrichment analysis was performed on the differentially expressed genes. Immunohistochemical (IHC) of FAT1 in pancreatic adenocarcinoma and normal pancreatic tissues was analyzed by HPA database. (2) Validation of own tissue samples: tissue samples and clinical and prognostic data of 192 patients with pancreatic ductal adenocarcinoma admitted to Zhejiang Cancer Hospital from March 8, 2010 to September 30, 2020 were collected. IHC was performed on the tissue samples to verify the protein expression of FAT1 in pancreatic adenocarcinoma and its relationship with immune-related proteins, the degree of differentiation of pancreatic adenocarcinoma, clinical staging, and prognosis.Results:(1) Bioinformatics analysis: the FAT1 mRNA expression of 179 pancreatic adenocarcinoma tissues from the TCGA database was 5.55±1.04, which was higher than that of 328 normal pancreatic tissues with FAT1 mRNA from the GTEx database (2.95±0.53, P<0.001). FAT1-specific IHC images showed that FAT1 expression was generally high in pancreatic adenocarcinoma tissues, and FAT1 expression shifted from the cell membrane to the cytoplasm. The FAT1 mRNA expression in the highly differentiated group (31 cases), the moderately differentiated group (96 cases), and the lowly differentiated group (52 cases) were 4.99±1.46, 5.51±0.80, and 5.68±1.08, the expression of pancreatic adenocarcinoma tissues were all higher than that of normal pancreatic tissues (all P<0.001), and the FAT1 mRNA expression of the moderately differentiated group and the poorly differentiated group were all higher than that of the highly differentiated group (all P<0.001). The median progression-free survival time (PFS) and median overall survival time (OS) of the 90 patients in the FAT1 mRNA low-expression group were 16.5 and 24 months, respectively, which were longer than those of the 89 patients in the FAT1 mRNA high-expression group (median PFS and OS were 13 and 18 months, respectively; P-values were 0.011 and 0.005, respectively). Multifactorial Cox regression analysis showed that FAT1 mRNA expression level was an independent influencing factor for OS in pancreatic adenocarcinoma patients ( HR=1.47, 95% CI: 1.09-1.99). Correlation analysis showed that FAT1 mRNA expression in pancreatic adenocarcinoma was positively correlated with B-cell infiltration, CD8+ T-cell infiltration, neutrophil infiltration, macrophage infiltration, and myeloid dendritic cell infiltration ( ρ=0.27, P<0.001; ρ=0.28, P<0.001; ρ=0.32, P<0.001; ρ=0.21, P=0.004; ρ=0.32, P<0.001), and also positively correlated with mRNA expression of CD274, HAVCR2, and PDCD1LG2 ( r=0.327, P<0.001; r=0.231, P=0.002; r=0.258, P<0.001). GO and KEGG enrichment analyses showed that FAT1 mRNA expression levels were associated with activation of the Wnt signaling pathway ( P=0.029), the PI3K/Akt pathway ( P<0.001), and other tumor microenvironment-related pathways. (2) Validation of own tissue samples: among 192 pancreatic adenocarcinoma tissues, FAT1 was highly expressed in 58 cases (30.21%), and the proportion of FAT1-expressing positive tumor cells was positively correlated with the combined positive score of PD-L1 and the number of CD3+ T-cells infiltration ( r=0.154, P=0.032; r=0.287, P<0.001), and the protein expression of FAT1 had no correlation with the differentiation degree of pancreatic adenocarcinoma ( ρ=0.082, P=0.254). The median OS of 58 patients in the FAT1 high-expression group and 134 patients in the FAT1 low-expression group were 18.89 and 25.84 months, respectively, and the difference was not statistically significant (χ2=1.93, P=0.165). Conclusion:FAT1 gene is highly expressed in pancreatic adenocarcinoma tissues, may play an oncogenic role in pancreatic adenocarcinoma, may be an adverse influence on overall survival and progression-free survival of patients; FAT1 gene may be involved in multiple immune-related pathways and promote tumor immune escape.
3.Expression and clinical significance of FAT1 gene in pancreatic adenocarcinoma
Xinyuan LIU ; Ying YANG ; Chaodan YANG ; Zhengxiao MA ; Conghui WU ; Chen XU ; Rui ZHU ; Pan LIU ; Lisha YING ; Wenjuan YIN ; Dan SU
Chinese Journal of Oncology 2024;46(11):1029-1037
Objective:To analyze the expression of FAT1 gene in pancreatic adenocarcinoma and its relationship with clinicopathological features, prognosis, and immunotherapy for pancreatic adenocarcinoma.Methods:(1) Bioinformatics analysis: based on FAT1 mRNA expression and clinical data of 179 cases of pancreatic adenocarcinoma in the TCGA database, and FAT1 mRNA expression data of 328 cases of normal pancreatic tissues in the GTEx database. We analyzed the differences in FAT1 mRNA expression in pancreatic adenocarcinoma and normal pancreatic tissues and the relationship between FAT1 mRNA expression and the degree of differentiation, clinical stage, prognosis, immune cell infiltration, and immune checkpoint-associated genes in pancreatic adenocarcinoma. FAT1-related differentially expressed genes were analyzed by applying Limma 3.40.2 software package, and GO and KEGG enrichment analysis was performed on the differentially expressed genes. Immunohistochemical (IHC) of FAT1 in pancreatic adenocarcinoma and normal pancreatic tissues was analyzed by HPA database. (2) Validation of own tissue samples: tissue samples and clinical and prognostic data of 192 patients with pancreatic ductal adenocarcinoma admitted to Zhejiang Cancer Hospital from March 8, 2010 to September 30, 2020 were collected. IHC was performed on the tissue samples to verify the protein expression of FAT1 in pancreatic adenocarcinoma and its relationship with immune-related proteins, the degree of differentiation of pancreatic adenocarcinoma, clinical staging, and prognosis.Results:(1) Bioinformatics analysis: the FAT1 mRNA expression of 179 pancreatic adenocarcinoma tissues from the TCGA database was 5.55±1.04, which was higher than that of 328 normal pancreatic tissues with FAT1 mRNA from the GTEx database (2.95±0.53, P<0.001). FAT1-specific IHC images showed that FAT1 expression was generally high in pancreatic adenocarcinoma tissues, and FAT1 expression shifted from the cell membrane to the cytoplasm. The FAT1 mRNA expression in the highly differentiated group (31 cases), the moderately differentiated group (96 cases), and the lowly differentiated group (52 cases) were 4.99±1.46, 5.51±0.80, and 5.68±1.08, the expression of pancreatic adenocarcinoma tissues were all higher than that of normal pancreatic tissues (all P<0.001), and the FAT1 mRNA expression of the moderately differentiated group and the poorly differentiated group were all higher than that of the highly differentiated group (all P<0.001). The median progression-free survival time (PFS) and median overall survival time (OS) of the 90 patients in the FAT1 mRNA low-expression group were 16.5 and 24 months, respectively, which were longer than those of the 89 patients in the FAT1 mRNA high-expression group (median PFS and OS were 13 and 18 months, respectively; P-values were 0.011 and 0.005, respectively). Multifactorial Cox regression analysis showed that FAT1 mRNA expression level was an independent influencing factor for OS in pancreatic adenocarcinoma patients ( HR=1.47, 95% CI: 1.09-1.99). Correlation analysis showed that FAT1 mRNA expression in pancreatic adenocarcinoma was positively correlated with B-cell infiltration, CD8+ T-cell infiltration, neutrophil infiltration, macrophage infiltration, and myeloid dendritic cell infiltration ( ρ=0.27, P<0.001; ρ=0.28, P<0.001; ρ=0.32, P<0.001; ρ=0.21, P=0.004; ρ=0.32, P<0.001), and also positively correlated with mRNA expression of CD274, HAVCR2, and PDCD1LG2 ( r=0.327, P<0.001; r=0.231, P=0.002; r=0.258, P<0.001). GO and KEGG enrichment analyses showed that FAT1 mRNA expression levels were associated with activation of the Wnt signaling pathway ( P=0.029), the PI3K/Akt pathway ( P<0.001), and other tumor microenvironment-related pathways. (2) Validation of own tissue samples: among 192 pancreatic adenocarcinoma tissues, FAT1 was highly expressed in 58 cases (30.21%), and the proportion of FAT1-expressing positive tumor cells was positively correlated with the combined positive score of PD-L1 and the number of CD3+ T-cells infiltration ( r=0.154, P=0.032; r=0.287, P<0.001), and the protein expression of FAT1 had no correlation with the differentiation degree of pancreatic adenocarcinoma ( ρ=0.082, P=0.254). The median OS of 58 patients in the FAT1 high-expression group and 134 patients in the FAT1 low-expression group were 18.89 and 25.84 months, respectively, and the difference was not statistically significant (χ2=1.93, P=0.165). Conclusion:FAT1 gene is highly expressed in pancreatic adenocarcinoma tissues, may play an oncogenic role in pancreatic adenocarcinoma, may be an adverse influence on overall survival and progression-free survival of patients; FAT1 gene may be involved in multiple immune-related pathways and promote tumor immune escape.
4.The biologically and ecologically important natural products from the Chinese sea hare Bursatella leachii:structures,stereochemistry and beyond
Xinyuan ZHANG ; Mingzhi SU ; Mingxin ZHU ; Sha CHEN ; Zhen GAO ; Yuewei GUO ; Xuwen LI
Chinese Journal of Natural Medicines (English Ed.) 2024;22(11):1030-1039
A novel amide alkaloid,bursatamide A(1),featuring an unprecedented propyl-hexahydronaphthalene carbon frame-work,was isolated from the infrequently studied sea hare Bursatella leachi,alongside a new 3-phenoxypropanenitrile alkaloid,bursatellin B(2),and twelve known compounds.The structures of 1 and 2 were elucidated through comprehensive spectroscopic data analyses,while their relative and absolute configurations(ACs)were established through total synthesis and a series of quantum chem-ical calculations,including calculated electronic circular dichroism(ECD)spectra,optical rotatory dispersion(ORD)methods,and DP4+probability analyses.Bursatamide A(1)demonstrated inhibitory effects against the human pathogenic bacteria Listeria monocyt-ogenes and Vibrio cholerae.Erythro-bursatellin B(21),a diastereoisomer of 2,exhibited notable antibacterial activity against the fish pathogenic bacterium Streptococcus parauberis FP KSP28,with an MIC90 value of 0.0472 μg·mL-1.
5.Test for geometric accuracy of imaging for magnetic resonance-guided radiotherapy
Ji ZHU ; Xinyuan CHEN ; Shirui QIN ; Zhuanbo YANG ; Ying CAO ; Kuo MEN ; Jianrong DAI
Chinese Journal of Medical Physics 2024;41(8):925-930
Objective To evaluate the effects of the multiple factors especially image geometric accuracy of the imaging system on the segmentations of target areas and organs-at-risk.Methods The study used phantoms to test the imaging performance of the 1.5T magnetic resonance(MR)linear accelerator system,including the assessments of MR image geometric distortion and the segmentation errors caused by factors such as image geometric distortion.Model 604-GS large field MR image distortion phantom was used to explore the geometric distortion of the MR images for MR-guided radiotherapy;and CIRS Model 008z upper abdominal phantom was used to analyze the segmentation errors of target areas and organs-at-risk.Results The average geometric distortion and maximum distortion of 3D T1WI-FFE images vs 3D T2WI-TSE images were 0.54 mm vs 0.53 mm and 1.96 mm vs 1.68 mm,respectively;and the control points of the large distortions were distributed at the edges of the phantom,which was consistent with the MR imaging characteristics previously reported.Compared with CT-based segmentation contour,the MDA was 1.17 mm and DSC was 0.91 for 3D T1WI-FFE,while MDA was 0.86 mm and DSC was 0.94 for 3D T2WI-TSE.Conclusion The study quantitatively assesses the geometric accuracy of the imaging system for MR-guided radiotherapy.The phantom-based contour analysis reveals that with CT image as gold standard,the segmentation error in MRI images meets the clinical requirements,and that 3D T2WI-TSE image is advantageous over 3D T1WI-FFE image in segmentation accuracy.
6.Feasibility analysis of dose calculation for nasopharyngeal carcinoma radiotherapy planning using MRI-only simulation
Xuejie XIE ; Guoliang ZHANG ; Siqi YUAN ; Yuxiang LIU ; Yunxiang WANG ; Bining YANG ; Ji ZHU ; Xinyuan CHEN ; Kuo MEN ; Jianrong DAI
Chinese Journal of Radiation Oncology 2024;33(5):446-453
Objective:To evaluate the feasibility of using MRI-only simulation images for dose calculation of both photon and proton radiotherapy for nasopharyngeal carcinoma cases.Methods:T 1-weighted MRI images and CT images of 100 patients with nasopharyngeal carcinoma treated with radiotherapy in Cancer Hospital of Chinese Academy of Medical Sciences from January 2020 to December 2021 were retrospectively analyzed. MRI images were converted to generate pseudo-CT images by using deep learning network models. The training set, validation set and test set included 70 cases, 10 cases and 20 cases, respectively. Convolutional neural network (CNN) and cycle-consistent generative adversarial neural network (CycleGAN) were exploited. Quantitative assessment of image quality was conducted by using mean absolute error (MAE) and structural similarity (SSIM), etc. Dose assessment was performed by using 3D-gamma pass rate and dose-volume histogram (DVH). The quality of pseudo-CT images generated was statistically analyzed by Wilcoxon signed-rank test. Results:The MAE of the CNN and CycleGAN was (91.99±19.98) HU and (108.30±20.54) HU, and the SSIM was 0.97±0.01 and 0.96±0.01, respectively. In terms of dosimetry, the accuracy of pseudo-CT for photon dose calculation was higher than that of the proton plan. For CNN, the gamma pass rate (3 mm/3%) of the photon radiotherapy plan was 99.90%±0.13%. For CycleGAN, the value was 99.87%±0.34%. The gamma pass rates of proton radiotherapy plans were 98.65%±0.64% (CNN, 3 mm/3%) and 97.69%±0.86% (CycleGAN, 3 mm/3%). For DVH, the dose calculation accuracy in the photon plan of pseudo-CT was better than that of the proton plan.Conclusions:The deep learning-based model generated accurate pseudo-CT images from MR images. Most dosimetric differences were within clinically acceptable criteria for photon and proton radiotherapy, demonstrating the feasibility of an MRI-only workflow for radiotherapy of nasopharyngeal cancer. However, compared with the raw CT images, the error of the CT value in the nasal cavity of the pseudo-CT images was relatively large and special attention should be paid during clinical application.
7.Research advances in hippocampal neurogenesis and epilepsy in high-altitude area
Journal of Apoplexy and Nervous Diseases 2024;41(12):1102-1105
Epilepsy is a clinical syndrome caused by highly synchronized abnormal discharges of brain neurons due to various causes. Studies have shown that abnormal hippocampal neurogenesis is observed in both human epilepsy patients and animal models of epilepsy, and abnormal neurogenesis can alter normal neural circuits in the hippocampus and promote the development of hippocampal sclerosis, ultimately leading to the development and progression of epilepsy. The low-pressure hypoxic environment unique to the plateau affects hippocampal neurogenesis by regulating hypoxia-inducible factors, the Wnt signaling pathway, the Notch signaling pathway, and EPO, thereby affecting the susceptibility to epilepsy and the development and progression of epilepsy. This article reviews the mechanism of interaction between hippocampal neurogenesis and epilepsy in high-altitude hypoxic environments, in order to provide potential strategies and targets for the treatment of epilepsy.
Neurogenesis
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Hippocampus
8.Comprehensive Evaluation of Health Status of Traditional Chinese Medicine Constitution based on Improved Radar Chart
Xinyuan ZHAO ; Yanbo ZHU ; Jianni CONG ; Liqun LONG ; Xiaoying LYU ; Qian ZHANG
Journal of Traditional Chinese Medicine 2023;64(19):2003-2009
ObjectiveTo present the health status of traditional Chinese medicine (TCM) constitutions more intuitively and comprehensively based on improved radar chart. MethodsParticipants who completed a 26-week comprehensive intervention based on TCM constitution from February 2013 to January 2014 in Zhuhai branch of Guangdong Provincial Hospital of Chinese Medicine were included in the study. They were divided into groups according to gender and age, i.e. young, middle-aged, and elderly male and female groups. TCM constitution scale and health survey short form (SF-36) were used to evaluate the 9 basic TCM constitution types and quality of life at three time points, including pre-intervention (T1), at 13-week intervention (T2), and at 26-week intervention (T3). The improved radar charts were drawn to visually present the comprehensive evaluation results on the health status of 9 TCM constitutions, and graphic features (area S value, perimeter L value) were extracted to construct a comprehensive health index for TCM constitutions (H value). Spearman correlation analysis was used to analyze the correlation between H value and SF-36 total score. ResultsAmong the included 509 participants, there were 45 elderly male, 76 elderly female, 60 middle-aged male, 140 middle-aged female, 53 young male and 135 young female. The radar charts for comprehensive evaluation of TCM constitution health status showed that the total areas for all groups increased at T3 compared to T1, with the most significant increase in the young population. In the middle-aged population, the fan-shaped areas of certain constitutions decreased at T2 than T1. At T3, the radar chart shapes for females were more balanced than males in the same age group. By calculating the features of function graphs, it was found that the S, L, and H values for the elderly population were relatively higher than those for the middle-aged and young population with the same gender, and the young population increased by highest ratio. The values measured at T3 compared to T1 showed average increase of 26% for S value (11% for the middle-aged and 14% for the elderly), 22% for L value (10% for the middle-aged and the elderly each), and 22% for H value (10% for the middle-aged and 9% for the elderly). The female had lower S and L values, as well as higher H value than the male of the same age group measured at T3. The correlation coefficient between the H value of all participants and the total SF-36 score was 0.662 (P<0.01). ConclusionThe comprehensive evaluation model for the health status of TCM constitution based on the improved radar chart constructed in this study can present the health status of TCM constitutions and intervention effectiveness more comprehensively and intuitively. It is suggested to regulate the constitution in pursuit of the dynamic balance of the constitution health status, as well as consider the parts from the whole, and put focus on the balance of nine TCM constitutions.
9.Global characterization of modifications to the charge isomers of IgG antibody
Xinling CUI ; Wei MI ; Zhishang HU ; Xiaoyu LI ; Bo MENG ; Xinyuan ZHAO ; Xiaohong QIAN ; Tao ZHU ; Wantao YING
Journal of Pharmaceutical Analysis 2022;12(1):156-163
Posttranslational modifications of antibody products affect their stability,charge distribution,and drug activity and are thus a critical quality attribute.The comprehensive mapping of antibody modifications and different charge isomers(CIs)is of utmost importance,but is challenging.We intended to quanti-tatively characterize the posttranslational modification status of CIs of antibody drugs and explore the impact of posttranslational modifications on charge heterogeneity.The CIs of antibodies were fraction-ated by strong cation exchange chromatography and verified by capillary isoelectric focusing-whole column imaging detection,followed by stepwise structural characterization at three levels.First,the differences between CIs were explored at the intact protein level using a top-down mass spectrometry approach;this showed differences in glycoforms and deamidation status.Second,at the peptide level,common modifications of oxidation,deamidation,and glycosylation were identified.Peptide mapping showed nonuniform deamidation and glycoform distribution among CIs.In total,10 N-glycoforms were detected by peptide mapping.Finally,an in-depth analysis of glycan variants of CIs was performed through the detection of enriched glycopeptides.Qualitative and quantitative analyses demonstrated the dynamics of 24 N-glycoforms.The results revealed that sialic acid modification is a critical factor ac-counting for charge heterogeneity,which is otherwise missed in peptide mapping and intact molecular weight analyses.This study demonstrated the importance of the comprehensive analyses of antibody CIs and provides a reference method for the quality control of biopharmaceutical analysis.
10.Noise reduction in low-dose computed tomography with noise equivalent image and deep learning
Bining YANG ; Yuxiang LIU ; Xinyuan CHEN ; Ji ZHU ; Ying CAO ; Kuo MEN
Chinese Journal of Radiological Medicine and Protection 2022;42(5):355-360
Objective:To investigate the method of simulating low-dose CT (LDCT) images using routine dose level scanning mode to generate LDCT images with correspondence to the routine dose CT (RDCT) images in the training sets for deep learning model, which would be used for LDCT noise reduction.Methods:The CT images reconstructed by different algorithms in Philips CT Big Core had different noise levels, where the noise was larger with iDose 4 algorithm and lower with IMR(knowledge-based iterative model reconstruction)algorithm. A new method of replacing LDCT image with noise equivalent reconstructed image was proposed. The uniform module of CTP712 was scanned with the exposure of 250 mAs for RDCT, 35 mAs for LDCT. The images were reconstructed using IMR algorithm for LDCT images and iDose 4 algorithm at multiple noise reduction levels for RDCT images, respectively. The noise distribution of each image set was analyzed to find the noise equivalent images of LDCT. Then, RDCT images, those selected images were used for training cycle-consistent adversarial networks (CycleGAN)model, and the noise reduction ability of the proposed method on real LDCT images of phantom was tested. Results:The RDCT images generated with iDose 4 level 1 could substitute the LDCT images reconstructed with IMR algorithm. The radiation dose was reduced by 86% in low dose scanning. Using CycleGAN model, the noise reduction degree was 45% for uniform module, and 50%, 13%, 7% for CIRS-SBRT 038 phantom in the specific regions of brain, spinal cord, bone, respectively. Conclusions:Equivalent noise level reconstructed images could potentially serve as the alternative of LDCT images for deep learning network training to avoid additional radiation dose. The generated CT images had substantially reduced noise relative to that of LDCT.

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