Objective To investigate the distribution characteristics of pathogens causing infections within 90 days after liver transplantation and the influencing factors of infection. Methods Clinical data of 176 recipients who underwent liver transplantation at the Liver Transplant Center of Beijing Friendship Hospital Affiliated to Capital Medical University from September 2021 to August 2024 were retrospectively analyzed. Patients were divided into the infection group (n=124) and the non-infection group (n=52) based on whether they developed infection within 90 days after transplantation. The distribution characteristics of pathogens in infected patients were analyzed. Univariate and multivariate logistic regression analyses were used to explore the influencing factors of infection. Results Among the 176 liver transplant recipients, 124 cases developed 243 episodes of 518 bacterial, fungal, viral or mycoplasma infections within 90 days after transplantation, with an overall infection rate of 70.5% (124/176). The composition of pathogens was mainly Gram-negative bacteria (38.6%, 200/518), followed by Gram-positive bacteria (32.2%, 167/518) and viruses (15.4%, 80/518), and fungi accounted for 13.1% (68/518). Among Gram-negative bacteria, the main pathogen was Klebsiella pneumoniae (6.8%, 35/518), and among Gram-positive bacteria, the main pathogen was Enterococcus faecalis (8.5%, 44/518). Viruses included Epstein-Barr virus (3.7%, 19/518) and cytomegalovirus (3.7%, 19/518), and fungi were mainly Candida albicans (6.8%, 35/518). The most common infection site among the 243 episodes was pulmonary infection (42.0%, 102/243), followed by abdominal infection (22.6%, 55/243) and bloodstream infection (18.1%, 44/243). The infections mainly occurred within 2 weeks after transplantation (60.9%, 148/243). Multivariate logistic regression analysis indicated that preoperative infection within 2 weeks, a high preoperative model for end-stage liver disease (MELD) score, and preoperative sarcopenia were independent risk factors for infection within 90 days after liver transplantation (all odds ratio>1, P<0.05). After multivariate correction, the levels of CD4⁺T cells and CD8⁺T cells within 90 days after surgery were independently associated with the occurrence of infection. Low levels of CD4⁺T cells and CD8⁺T cells might be related to an increased risk of infection. Conclusions The infection rate after liver transplantation is high, and the pathogens are mainly Gram-negative bacteria. The lungs are the most common infection site. Preoperative MELD score, preoperative sarcopenia and preoperative infection within 2 weeks are independent risk factors for infection within 90 days after liver transplantation. Regular monitoring of immune indicators CD4⁺T cells and CD8⁺T cells levels after transplantation is helpful to reduce the occurrence of post-transplantation infection.

After the occurrence of acute rejection following solid organ transplantation, high-dose glucocorticoid (steroid) pulse therapy is commonly used. However, high-dose steroid pulse therapy is ineffective for some patients, leading to steroid resistant acute rejection, which may easily result in graft loss and severely affect patient prognosis. It is currently believed that both cell-mediated rejection and antibody-mediated rejection are involved in the occurrence and development of steroid resistant acute rejection. The diagnosis and treatment of steroid resistant acute rejection after kidney transplantation have become relatively mature, while the focus on steroid resistant acute rejection after liver transplantation has been relatively low in the past in China, and a unified standardized treatment plan has not yet been formed. Therefore, this article reviews the pathogenesis, diagnosis, and treatment of steroid resistant acute rejection after liver transplantation, in order to provide a reference for the diagnosis and treatment of steroid resistant acute rejection after liver transplantation.

Ferroptosis is a form of programmed cell death,which plays a crucial driving role in the onset and progression of diabetic nephropathy(DN).Ferroptosis is closely related to the damage of renal intrinsic cells in patients with diabetes.Chinese materia medica can improve DN by regulating the ferroptosis of renal intrinsic cells,with a good research and application prospect.This article reviewed the key regulatory factors and regulatory pathways of ferroptosis in DN,explained the"imbalance between yin and yang"of ferroptosis in DN based on TCM theories,and combed the research status of targeted inhibition of ferroptosis by active components of Chinese materia medica.The regulation of active components of Chinese materia medica on ferroptosis in DN has the characteristics of multiple targets,multiple links and integrity,which can provide a reference for the mechanism research and drug development of Chinese materia medica in treating DN.

Objective:To analyze the efficacy of endovascular treatment for venous outflow tract obstruction after liver transplantation.Methods:A retrospective analysis was conducted on the data of 7 patients with venous outflow tract obstruction after liver transplantation admitted to Beijing Friendship Hospital, Capital Medical University from November 2020 to December 2024. Among them, there were 5 males and 2 females, with the age of (22.3±8.1) years. The primary diseases included 2 cases of Budd-Chiari syndrome, 1 case of hepatic veno-occlusive disease, 1 case of portal veno-hepatic sinus vascular disease, 1 case of ornithine carbamoyltransferase deficiency, 1 case of primary biliary cirrhosis, and 1 case of autoimmune cirrhosis. Analyze the patient's clinical manifestations, obstruction of venous outflow tract, hemoglobin levels within one week before and one week after the operation, endovascular treatment conditions, and intraoperative complications such as abdominal hemorrhage and vascular injury. Ultrasound was used to measure the depth of ascites and pleural effusion. All patients were followed up immediately after the operation through phone calls or follow-up visits. The clinical symptoms, abdominal vascular ultrasound, enhanced CT and survival status of the patients were followed up.Results:All 7 patients were diagnosed with venous outflow tract obstruction by intraoperative angiography, including 1 cases of inferior vena cava obstruction, 2 cases of hepatic vein obstruction, and 4 cases of vena cava combined with hepatic vein obstruction. A total of 12 endovascular treatments were performed on 7 patients. Among them, 4 patients received balloon dilation and angioplasty once, 1 patient received balloon dilation and angioplasty twice, 1 patient underwent hepatic vein stent implantation after 2 hepatic vein balloon dilation and angioplasty, and 1 patient underwent intrahepatic portosystemic shunt via jugular vein after 2 hepatic vein balloon dilation and angioplasty. The abdominal distensionof the patients were all relieved after the operation, the ascites and pleural effusion decreased, and the edema symptoms of the lower extremities disappeared. There were no intraoperative complications. The preoperative hemoglobin of 7 patients was (113.4±34.0) g/L, and the postoperative hemoglobin was (126.6±34.8) g/L, which increased significantly compared with that before the operation, and the difference was statistically significant ( t=-0.71, P=0.038). Seven patients were followed up for 6 to 24 months, with a median of 12 months. None of them had obvious symptoms including abdominal distension. Abdominal ultrasound and CT indicated that the blood flow of the transplanted liver was unobstructed, and no patient died. Conclusion:Venous outflow tract obstruction after liver transplantation can cause severe symptoms. Endovascular treatment is an effective treatment for venous outflow tract obstruction after liver transplantation.

Objective:To explore the molecular mechanism by which interferon regulatory factor 1 (IRF1) affects hepatic ischemia-reperfusion injury (HIRI) by regulating the polarization of Kupffer cells.Methods:Twelve male healthy C57BL/6 wild-type mice weighing 20-25 g and aged 6-8 weeks were divided into a sham operation group ( n=6) and a HIRI group ( n=6); Twelve male healthy C57BL/6 IRF1 gene knockout (IRF1 -/-) mice weighing 20-25 g and aged 6-8 weeks were divided into a sham operation IRF1 -/- group ( n=6) and a HIRI IRF1 -/- group ( n=6). The levels of serum alanine transaminase (ALT) and aspartate transaminase (AST) in mice were measured, and hematoxylin-eosin (HE) staining of liver tissues was performed for Suzuki scoring to evaluate liver injury. Fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to evaluate the mRNA levels of IRF1 and tumor necrosis factor α (TNFα) in liver tissues. Flow cytometry and qRT-PCR were used to detect the proportion and functional changes of M1/M2-type Kupffer cells in liver tissues. IRF1 was overexpressed or knocked down in the mononuclear macrophage cell line ANA1, and a co-culture and hypoxia-reoxygenation system with the hepatocyte cell line AML12 was established. Flow cytometry was used to detect the apoptosis of AML12 cells. Results:At 12 hours after hepatic ischemia-reperfusion in wild-type mice, the liver tissue injury was the most severe. Compared with the sham operation group, the levels of serum ALT [(8 073±83) U/L vs. (81±19) U/L, q=13.59] and AST [(11 170±2 890) U/L vs. (412±210) U/L, q=13.77] in the HIRI group were significantly higher, and the differences were statistically significant (both P<0.001). The Suzuki score reached 5-6 points. At 12 hours after hepatic ischemia-reperfusion in IRF1 gene knockout mice, the liver tissue injury was not obvious. There were no significant differences in the levels of serum ALT [668 (514, 2 344) U/L vs. 254 (147, 285) U/L, q=2.52, P=0.348] and AST [1 936 (1 262, 2 003) U/L vs. 628 (423, 759) U/L, q=1.22, P=0.824] between the HIRI IRF1 -/- group and the sham operation IRF1 -/- group. Compared with the HIRI group, the ratio of M1/M2-type Kupffer cells in the liver of the HIRI IRF1 -/- group decreased [(0.958±0.090) vs. (2.788±0.258), q=2.06, P<0.0001], and the mRNA expression of TNFα decreased [(4.363±0.393) vs. (12.900±5.504), q=5.59, P=0.018], and the differences between the two groups were statistically significant. In the co-culture and hypoxia-reoxygenation experiment using ANA1 cells overexpressing IRF1 and AML12 cells, the proportion of AML12 hepatocytes in late apoptosis was higher than that in the control group [(14.05±4.25) vs. (3.15±1.16), t=2.85, P=0.047], and the difference was statistically significant. In contrast, when the expression of IRF1 was knocked down, the proportion of apoptotic AML12 cells decreased [(9.26±3.04) vs. (13.36±4.64), t=2.15, P=0.098], but the difference was not statistically significant. Conclusion:The IRF1 protein can regulate the polarization of Kupffer cells into M1-type macrophages, promote the inflammatory injury of the liver tissue after ischemia-reperfusion, and increase the apoptosis of hepatocytes.

Ferroptosis is a form of programmed cell death,which plays a crucial driving role in the onset and progression of diabetic nephropathy(DN).Ferroptosis is closely related to the damage of renal intrinsic cells in patients with diabetes.Chinese materia medica can improve DN by regulating the ferroptosis of renal intrinsic cells,with a good research and application prospect.This article reviewed the key regulatory factors and regulatory pathways of ferroptosis in DN,explained the"imbalance between yin and yang"of ferroptosis in DN based on TCM theories,and combed the research status of targeted inhibition of ferroptosis by active components of Chinese materia medica.The regulation of active components of Chinese materia medica on ferroptosis in DN has the characteristics of multiple targets,multiple links and integrity,which can provide a reference for the mechanism research and drug development of Chinese materia medica in treating DN.

Objective:To analyze the efficacy of endovascular treatment for venous outflow tract obstruction after liver transplantation.Methods:A retrospective analysis was conducted on the data of 7 patients with venous outflow tract obstruction after liver transplantation admitted to Beijing Friendship Hospital, Capital Medical University from November 2020 to December 2024. Among them, there were 5 males and 2 females, with the age of (22.3±8.1) years. The primary diseases included 2 cases of Budd-Chiari syndrome, 1 case of hepatic veno-occlusive disease, 1 case of portal veno-hepatic sinus vascular disease, 1 case of ornithine carbamoyltransferase deficiency, 1 case of primary biliary cirrhosis, and 1 case of autoimmune cirrhosis. Analyze the patient's clinical manifestations, obstruction of venous outflow tract, hemoglobin levels within one week before and one week after the operation, endovascular treatment conditions, and intraoperative complications such as abdominal hemorrhage and vascular injury. Ultrasound was used to measure the depth of ascites and pleural effusion. All patients were followed up immediately after the operation through phone calls or follow-up visits. The clinical symptoms, abdominal vascular ultrasound, enhanced CT and survival status of the patients were followed up.Results:All 7 patients were diagnosed with venous outflow tract obstruction by intraoperative angiography, including 1 cases of inferior vena cava obstruction, 2 cases of hepatic vein obstruction, and 4 cases of vena cava combined with hepatic vein obstruction. A total of 12 endovascular treatments were performed on 7 patients. Among them, 4 patients received balloon dilation and angioplasty once, 1 patient received balloon dilation and angioplasty twice, 1 patient underwent hepatic vein stent implantation after 2 hepatic vein balloon dilation and angioplasty, and 1 patient underwent intrahepatic portosystemic shunt via jugular vein after 2 hepatic vein balloon dilation and angioplasty. The abdominal distensionof the patients were all relieved after the operation, the ascites and pleural effusion decreased, and the edema symptoms of the lower extremities disappeared. There were no intraoperative complications. The preoperative hemoglobin of 7 patients was (113.4±34.0) g/L, and the postoperative hemoglobin was (126.6±34.8) g/L, which increased significantly compared with that before the operation, and the difference was statistically significant ( t=-0.71, P=0.038). Seven patients were followed up for 6 to 24 months, with a median of 12 months. None of them had obvious symptoms including abdominal distension. Abdominal ultrasound and CT indicated that the blood flow of the transplanted liver was unobstructed, and no patient died. Conclusion:Venous outflow tract obstruction after liver transplantation can cause severe symptoms. Endovascular treatment is an effective treatment for venous outflow tract obstruction after liver transplantation.

Objective:To explore the molecular mechanism by which interferon regulatory factor 1 (IRF1) affects hepatic ischemia-reperfusion injury (HIRI) by regulating the polarization of Kupffer cells.Methods:Twelve male healthy C57BL/6 wild-type mice weighing 20-25 g and aged 6-8 weeks were divided into a sham operation group ( n=6) and a HIRI group ( n=6); Twelve male healthy C57BL/6 IRF1 gene knockout (IRF1 -/-) mice weighing 20-25 g and aged 6-8 weeks were divided into a sham operation IRF1 -/- group ( n=6) and a HIRI IRF1 -/- group ( n=6). The levels of serum alanine transaminase (ALT) and aspartate transaminase (AST) in mice were measured, and hematoxylin-eosin (HE) staining of liver tissues was performed for Suzuki scoring to evaluate liver injury. Fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to evaluate the mRNA levels of IRF1 and tumor necrosis factor α (TNFα) in liver tissues. Flow cytometry and qRT-PCR were used to detect the proportion and functional changes of M1/M2-type Kupffer cells in liver tissues. IRF1 was overexpressed or knocked down in the mononuclear macrophage cell line ANA1, and a co-culture and hypoxia-reoxygenation system with the hepatocyte cell line AML12 was established. Flow cytometry was used to detect the apoptosis of AML12 cells. Results:At 12 hours after hepatic ischemia-reperfusion in wild-type mice, the liver tissue injury was the most severe. Compared with the sham operation group, the levels of serum ALT [(8 073±83) U/L vs. (81±19) U/L, q=13.59] and AST [(11 170±2 890) U/L vs. (412±210) U/L, q=13.77] in the HIRI group were significantly higher, and the differences were statistically significant (both P<0.001). The Suzuki score reached 5-6 points. At 12 hours after hepatic ischemia-reperfusion in IRF1 gene knockout mice, the liver tissue injury was not obvious. There were no significant differences in the levels of serum ALT [668 (514, 2 344) U/L vs. 254 (147, 285) U/L, q=2.52, P=0.348] and AST [1 936 (1 262, 2 003) U/L vs. 628 (423, 759) U/L, q=1.22, P=0.824] between the HIRI IRF1 -/- group and the sham operation IRF1 -/- group. Compared with the HIRI group, the ratio of M1/M2-type Kupffer cells in the liver of the HIRI IRF1 -/- group decreased [(0.958±0.090) vs. (2.788±0.258), q=2.06, P<0.0001], and the mRNA expression of TNFα decreased [(4.363±0.393) vs. (12.900±5.504), q=5.59, P=0.018], and the differences between the two groups were statistically significant. In the co-culture and hypoxia-reoxygenation experiment using ANA1 cells overexpressing IRF1 and AML12 cells, the proportion of AML12 hepatocytes in late apoptosis was higher than that in the control group [(14.05±4.25) vs. (3.15±1.16), t=2.85, P=0.047], and the difference was statistically significant. In contrast, when the expression of IRF1 was knocked down, the proportion of apoptotic AML12 cells decreased [(9.26±3.04) vs. (13.36±4.64), t=2.15, P=0.098], but the difference was not statistically significant. Conclusion:The IRF1 protein can regulate the polarization of Kupffer cells into M1-type macrophages, promote the inflammatory injury of the liver tissue after ischemia-reperfusion, and increase the apoptosis of hepatocytes.

Objective To observe the value of artificial intelligence iterative reconstruction(AIIR)combined with 60 kVp scanning in craniocervical CT angiography(CTA).Methods Eighty-six patients with suspected craniocervical vascular diseases were prospectively enrolled and randomly received routine-dose(120 kVp)or low-dose(60 kVp)scanning(each n=43),and contrast dosage and radiation dose were recorded.After scanning,hybrid iterative reconstruction(HIR)was used to reconstruct routine-dose images(group A),while HIR images(group B1)and AIIR images(group B2)were performed to reconstruct low-dose images,respectively.The overall imaging quality,visualization of targeted large and small vessels and diagnostic confidence scores,as well as image noise(SD),signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of targeted large vessels were compared among 3 groups.Results Contrast dosage and effective dose(ED)decreased by 36.52％ and 77.56％ in low-dose scanning compared with those in routine-dose scanning,respectively.No significant difference of subjective scoring of imaging quality indexes was found between groups B2 and A(all adjusted P＞0.05),which were both higher than those in group B1(all adjusted P＜0.05).SD of target large vessels in group B2 than that of most target large vessels in group A(all adjusted P＜0.05)except for aortic arch.SNR and CNR of target large vessels in group B2 were higher than those in group A and B1(all adjusted P＜0.05),while SD of target large vessels in group B2 were lower than in group B1.Conclusion AIIR combined with 60 kVp scanning in craniocervical CTA could meet diagnostic requirements of imaging quality and reduce contrast dosage and radiation dose.

Objective To observe the value of artificial intelligence iterative reconstruction(AIIR)for low-dose chest CT images of infants with congenital heart disease.Methods Totally 262 infants with congenital heart disease who would undergo chest CT scanning were prospectively enrolled and randomly divided into low-dose group(n=142)and conventional dose group(n=120).Chest CT scanning with tube voltage of 80 kVp and tube current of 10 mAs was performed in low-dose group,and hybrid iterative reconstruction(HIR,group A)and AIIR(group B)were used to reconstruct images,respectively.In conventional dose group,chest CT scanning with tube voltage of 80 kVp and tube current of 100 mAs was performed,and HIR was used to reconstruct images(group C).Then subjective and objective evaluation on image quality were performed,the results were compared among 3 groups,and the value of AIIR was analyzed.Results Significant differences of image quality and clarity of displaying structures were found among 3 groups(all P＜0.001).Among them,except for the clarity of interlobar fissure,no significant difference of subjective scores was found between low-dose AIIR images and conventional dose HIR images(all corrected P＞0.05),while subjective scores of low-dose HIR images were all lower than those of low-dose AIIR images and conventional dose HIR images(all corrected P＜0.05).Significant differences of standard deviation(SD),signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were found among 3 groups(all P＜0.001)and between each 2 groups(all corrected P＜0.05).The effective dose of low-dose group and conventional dose group was 0.09(0.08,0.10)and 0.85(0.75,1.03)mSv,respectively,and the former was lower than the latter(Z=-13.942,P＜0.001).Conclusion Using AIIR could obtain low-dose chest CT images of infants with quality comparable to conventional chest CT images.