1.Effect of lower limb amputation on hemodynamic environment of the left coronary artery: a numerical study.
Tianxiang TAI ; Wentao JIANG ; Zhongyou LI ; Junjie DIAO ; Xiao LI
Journal of Biomedical Engineering 2025;42(5):954-963
It has been found that the incidence of cardiovascular disease in patients with lower limb amputation is significantly higher than that in normal people, and the risk of developing coronary atherosclerosis is much higher than that in other high-risk groups. Numerous studies have confirmed that high systolic and diastolic blood pressures are potential risk factors for coronary artery disease, and it has been demonstrated that the ascending aortic pressure during diastole increases after amputation. However, the relationship between lower limb amputation and coronary atherosclerosis has not been fully explained from the perspective of hemodynamic environment. Therefore, in this study, a centralized parameter model of the human cardiovascular system and a three-dimensional model of the left coronary artery were established to investigate the effect of amputation on the hemodynamic environment of the coronary artery. The results showed that the abnormal hemodynamic environment induced by amputation, characterized by factors such as increased diastolic pressure in the ascending aorta, led to a significant expansion of the low wall shear stress (WSS) region on the outer lateral aspect of the left coronary artery bifurcation during diastole. The maximum observed increase in the area of low WSS reached up to 50.5%. This abnormal hemodynamic environment elevates the risk of plaque formation in the left coronary artery. Moreover, the more severe the lower limb atrophy, the greater the risk of coronary atherosclerosis in amputees. This study preliminarily reveals the effect of lower limb amputation on the hemodynamic environment of the left coronary artery.
Humans
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Hemodynamics/physiology*
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Amputation, Surgical/adverse effects*
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Coronary Vessels/physiology*
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Coronary Artery Disease/etiology*
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Lower Extremity/surgery*
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Models, Cardiovascular
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Blood Pressure
4.M6A-mediated EGLN3 and FOSL2 enhance radioresistance in nasopharyngeal carcinoma
Tianxiang WANG ; Pingchuan ZHANG ; Kun CHEN ; Xia HE ; Li YIN
Chinese Journal of Radiation Oncology 2024;33(2):158-167
Objective:To screen and verify the key radioresistance genes regulated by m6A methylation in nasopharyngeal carcinoma (NPC) based on the chip data and cell experiments.Methods:The microarray data of NPC radioresistance genes, m6A regulated genes and mRNA expression profiles of NPC genes were downloaded from Gene Expression Omnibus (GEO) database. The differential genes were screened and statistically analyzed by R software. The biological processes, signal pathways and interaction networks of these genes were analyzed by bioinformatics. The m6A regulatory factors were knocked down and the radioresistant strains were constructed. The above m6A differential radioresistant genes of NPC were screened and verified by real-time reverse transcription PCR (qRT-PCR) and Western blot. The m6A modification of screened genes and their direct binding ability with methyltransferase 3 (METTL3) were verified by methylated RNA immunoprecipitation qPCR (MeRIP-qPCR). The siRNA of selected genes was transfected into NPC cells, and after treatment with ionizing radiation, cell proliferation was detected by CCK-8 assay and EdU, apoptosis and cell cycle were detected by flow cytometry, and radiosensitivity was detected by clone formation assay. The trend of differences in the abundance of Fe 2+ and lipid peroxidation between the control and EGLN3 knockdown groups after ionizing radiation treatment was compared by paired t-test. Results:Chip data GSE48501 intersected with GSE200792 and GSE53819 to obtain 6 differential genes, including EGLN3, FOSL2, ADM, JUN, VEGFA and PRDM1. The target genes of EGLN3 and FOSL2 were further screened by TNMplot and KMplot, etc. The mRNA of the target genes directly bound to METTL3 and were subjected to its mediated modification of m6A. The target genes were up-regulated in the parental cells after irradiation in a dose and time gradient manner, which were also significantly up-regulated in radioresistant cells. After EGLN3 and FOSL2 were down regulated, the proliferation activity of NPC cells was more significantly decreased after irradiation, and the radiosensitization ratio was statistically significant compared with that of NPC cells without EGLN3 and FOSL2 down-regulation. After irradiation, EGLN3 down-regulated NPC cells significantly down-regulated glutathione peroxidase 4 (GPX4) expression, increased the abundance of Fe 2+ and lipid peroxidation, which played a role in radiosensitization by inducing ferroptosis. Conclusions:EGLN3 and FOSL2 play a role in radioresistance in NPC through METTL3 mediated m6A methylation. Down-regulation of EGLN3 combined with ionizing radiation can increase the intracellular Fe 2+ abundance and lipid peroxidation and down-reuglate the expression of GPX4 in NPC cells, which can enhance radiosensitization for NPC radiotherapy by the ferroptosis pathway.
5.Research on the antimicrobial resistance monitoring system based on the One Health concept
LI Min ; JIANG Tianxiang ; CHEN Weiye
China Tropical Medicine 2024;24(11):1293-
Antimicrobial resistance (AMR), is regarded as one of the top 10 global public health threats. Addressing AMR through the One Health strategy has become a global consensus. AMR monitoring plays a crucial role as the cornerstone of AMR response strategies. This study thoroughly analyzed current situation and progress of AMR monitoring based on the One Health concept in China, the United Kingdom, the United States, and the European Union, and comprehensively compared the similarities and differences of AMR monitoring systems across these countries and regions. The research found that cross-national, cross-regional, and cross-sectoral cooperation in AMR monitoring is increasingly strengthening. However, notable discrepancies still exist among different countries and regions. Notably, most AMR monitoring systems prioritize human and animal health, with relatively insufficient monitoring in the environmental sector. Given the current landscape, China still needs to continue to promote standardized AMR monitoring data sharing and integration across the human, animal, food, and environmental fields, striving to construct a comprehensive and systematic "whole-chain" AMR monitoring system to better tackle this global public health challenge effectively.
6.Effects of 50 Hz electromagnetic field on rat working memory and investigation of neural mechanisms.
Longlong WANG ; Shuangyan LI ; Tianxiang LI ; Weiran ZHENG ; Yang LI ; Guizhi XU
Journal of Biomedical Engineering 2023;40(6):1135-1141
With the widespread use of electrical equipment, cognitive functions such as working memory (WM) could be severely affected when people are exposed to 50 Hz electromagnetic fields (EMF) for long term. However, the effects of EMF exposure on WM and its neural mechanism remain unclear. In the present paper, 15 rats were randomly assigned to three groups, and exposed to an EMF environment at 50 Hz and 2 mT for a different duration: 0 days (control group), 24 days (experimental group I), and 48 days (experimental group II). Then, their WM function was assessed by the T-maze task. Besides, their local field potential (LFP) in the media prefrontal cortex (mPFC) was recorded by the in vivo multichannel electrophysiological recording system to study the power spectral density (PSD) of θ and γ oscillations and the phase-amplitude coupling (PAC) intensity of θ-γ oscillations during the T-maze task. The results showed that the PSD of θ and γ oscillations decreased in experimental groups I and II, and the PAC intensity between θ and high-frequency γ (hγ) decreased significantly compared to the control group. The number of days needed to meet the task criterion was more in experimental groups I and II than that of control group. The results indicate that long-term exposure to EMF could impair WM function. The possible reason may be the impaired communication between different rhythmic oscillations caused by a decrease in θ-hγ PAC intensity. This paper demonstrates the negative effects of EMF on WM and reveals the potential neural mechanisms from the changes of PAC intensity, which provides important support for further investigation of the biological effects of EMF and its mechanisms.
Humans
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Rats
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Animals
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Memory, Short-Term/physiology*
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Electromagnetic Fields/adverse effects*
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Prefrontal Cortex
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Cognition
7.Effect of miR-524-5p on Epithelial-mesenchymal Transition in Esophageal Cancer Cells by Regulating HEG1 Expression
Yafei WANG ; Tianxiang GENG ; Linlin CHEN ; Zhiguo LI ; Shipeng LI
Cancer Research on Prevention and Treatment 2023;50(11):1059-1065
Objective To investigate the mechanism and the effect of miR-524-5p regulating HEG1 expression on the proliferation and epithelial-mesenchymal transition of esophageal cancer cells. Methods The expression levels of miR-524-5p and HEG1 mRNA in esophageal cancer cells and normal esophageal epithelial cells were detected by qRT-PCR. KYSE30 cells were divided into miR-524-5p mimic group, miR-524-5p NC group, miR-524-5p mimic+pcDNA3.1 group, and miR-524-5p mimic+pcDNA3.1-HEG1 group. Non-transfected cells were set as the normal control group (group Control). CCK-8 method was applied to detect the proliferation ability of KYSE30 cells. Western blot analysis was conducted to detect the expression of proteins related to EMT, invasion, and migration and the HEG1 protein. Scratch and Transwell assays were applied to detect the migration and invasion abilities of KYSE30 cells. A dual-luciferase reporter gene was used to examine the targeting relationship between miR-524-5p and HEG1. Results miR-524-5p was lowly expressed in four esophageal cancer cell lines, namely, TE-1, KYSE30, KYSE150, and NEC (
8.Research progress on radiobiological effects of ferroptosis in cancer
Tianxiang WANG ; Mingyu DU ; Pingchuan ZHANG ; Li YIN ; Xia HE
Chinese Journal of Radiation Oncology 2023;32(8):742-747
Ferroptosis is a new form of regulated cell death discovered in recent years, which is iron-dependent cell death characterized by peroxidation of polyunsaturated fatty acid phospholipids. Recent studies have shown that radiotherapy can induce ferroptosis in cancer cells via ionizing radiation. Targeting ferroptosis plays a synergistic role in tumor suppression with radiation, which not only further deepens the connotation of radiobiology, but also provides a new perspective for tumor radiosensitization. This review systematically summarizes the occurrence and defense of ferroptosis, focusing on the key role of ferroptosis in the radiobiological effects of tumor cells and the potential application of ferroptosis in radiosensitization.
9.Diagnosis and treatment of 12 cases of fumarate hydratase-deficient renal cell carcinoma
Yiming GUO ; Tianxiang BI ; Chaoliang WANG ; Qi LI
Journal of Modern Urology 2023;28(9):742-747
【Objective】 To summarize and analyze the clinical data of fumarate hydrase-deficient renal cell carcinoma (FH-RCC), so as to improve the understanding of the disease. 【Methods】 General clinical data of 12 FH-RCC patients treated during Mar.2019 and Dec.2021 were retrospectively analyzed, including the imaging, pathological, genetic testing, surgical and adjuvant therapy, and follow-up results. 【Results】 All cases were confirmed with pathology or genetic tests, including 1 case complicated with uterine fibroids, 3 cases with renal cysts, 4 with family history of uterine fibroids and 2 with family history of renal carcinoma. Cysticular irregular density shadows with an enhancement of 25.8 Hu were detected in 4 cases. Of the 7 cases undergoing genetic testing, 2 had embryo and system mutation, 1 had germ line mutation, 1 had system mutation, and 3 had no germ line or system mutation. Radical nephrotomy was performed in 9 cases. The average operation time was 3.8 h, and the average amount of blood loss was 625 mL. Immunotherapy with targeted therapy was conducted in 10 cases, surgery with postoperative adjuvant therapy in 7 cases, and tyrosine kinase inhibitor with immune checkpoint inhibitor (TKI/ICI) in 1 case. All 12 cases were followed up, 3 died of tumor, 1 had no recurrence, 8 showed progress on imaging. 【Conclusion】 FH-RCC is a rare and highly malignancy prone to metastasis. Imaging shows cystic solid space occupying lesions. FH immunohistochemical staining is negative. Genetic testing is needed to confirm the diagnosis. TKI/ICI combination therapy has a good survival benefit.
10.Animal experimental study on the effects of different levels of amputation on cardiovascular system.
Lei MIN ; Wentao JIANG ; Zhongyou LI ; Xiao LI ; Junjie DIAO ; Renjing LIU ; Tianxiang TAI ; Taoping BAI
Journal of Biomedical Engineering 2023;40(3):515-521
Vascular injury resulting from lower limb amputation leads to the redistribution of blood flow and changes in vascular terminal resistance, which can affect the cardiovascular system. However, there was no clear understanding of how different amputation levels affect the cardiovascular system in animal experiments. Therefore, this study established two animal models of above-knee amputation (AKA) and below-knee amputation (BKA) to explore the effects of different amputation levels on the cardiovascular system through blood and histopathological examinations. The results showed that amputation caused pathological changes in the cardiovascular system of animals, including endothelial injury, inflammation, and angiosclerosis. The degree of cardiovascular injury was higher in the AKA group than in the BKA group. This study sheds light on the internal mechanisms of amputation's impact on the cardiovascular system. Based on the amputation level of patients, the findings recommend more comprehensive and targeted monitoring after surgery and necessary interventions to prevent cardiovascular diseases.
Animals
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Animal Experimentation
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Cardiovascular System
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Cardiovascular Diseases
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Hypertension
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Amputation, Surgical

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