Internal fistula stenosis with true pseudoaneurysm formation in a patient on maintenance hemodialysis: A case report.

BACKGROUND: Arteriovenous fistula stenosis can directly lead to the formation of autologous arteriovenous fistula aneurysms (AVFAs), but the coexistence of true and pseudoaneurysms is relatively rare. The coexistence of true and pseudoaneurysms increases the risk of rupture of the arteriovenous fistula and complicates subsequent surgical intervention, potentially posing a threat to the patient's life, and thus requires significant attention. CASE PRESENTATION: The patient presented with arteriovenous fistula (AVF) after hemodialysis 6 years ago. 2 years ago, the patient presented with a mass that had formed near the left forearm arteriovenous fistula and gradually increased in size. Preoperatively, the AVF stenosis was identified as the cause of the mass formation, and the patient was operated on. First, the blood flow was controlled to reduce the pressure at the aneurysm, and then the incision was enlarged to separate the AVF anastomosis from the mass area. The stenotic segment of the true and pseudo aneurysms and cephalic vein was removed and the over-dilated proximal cephalic vein was locally narrowed and subsequently anastomosed with the proximal radial artery to create AVF. The patient was dialyzed with an internal fistula the next day and showed no clinical manifestations related to end-limb ischemia. CONCLUSION: We removed a true pseudoaneurysm in AVF and secured the patient's vascular access. This report provides an effective strategy to manage this condition.

[Prediction of the epitopes of SARS-CoV-2 by immunoinformatics].

Objective To predict the epitopes of B cells, cytotoxic T lymphocytes (CTL), and T helper (Th) cells of SARS-CoV-2 by immunoinformatics. Methods The SARS-CoV-2 protein sequences were retrieved from NCBI database and screened, and the sequences with antigenicity ≥0.5 and amino acid number ≥100 were used for epitopes prediction. The Phyre2 server was used to predict the three-dimensional (3D) structure, the GalaxyRefine system to optimize the 3D structure, and the SWISS-MODEL system to evaluate the accuracy of the optimized structure. The CTL, Th cells, and sequential B-cell antigen peptide prediction was based on the sequences of proteins, and the structural B-cell antigen peptide prediction on the 3D structures of proteins. The cytotoxic T lymphocyte (CTL) and Th cell epitopes of SARS-CoV-2 were predicted by the IEDB database. The sequential B-cell antigen peptide prediction and the structural B-cell antigen peptide prediction were performed by BepiPred-2.0: Sequential B-Cell Epitope Predictor and ElliPro-a structure-based tool for the prediction of epitopes, respectively. Results Twenty seven SARS-CoV-2 protein sequences were obtained from the NCBI database. After removing the proteins with antigenicity <0.5 and amino acid number <100, nine proteins were selected for antigen peptide prediction. Finally, 24 epitopes from CTLs, 20 epitopes from Th cells, and 12 sequential epitopes and 16 structural epitopes from B cells were obtained. Conclusion The epitopes obtained can be used for developing multi-epitope SARS-CoV-2 vaccines. Compared with epitopes that only target a single protein, multi-target epitopes have stronger immunogenicity. These epitopes have certain reference value for the development of SARS-CoV-2 vaccine.

Comparison of visceral, general and central obesity indices in the prediction of metabolic syndrome in maintenance hemodialysis patients.

PURPOSE: We aimed to compare the predictive ability of the anthropometric indices reflecting general, central and visceral obesity for identification of metabolic syndrome (MetS) in maintenance hemodialysis (MHD) patients. METHODS: A multicenter, cross-sectional study that consisted of 1603 adult MHD patients (54.6 ± 16 years) was conducted in Guizhou Province, Southwest China. Eight anthropometric obesity indexes including body mass index (BMI), waist circumference (WC), waist-height ratio (WHtR), conicity index (Ci) and visceral adiposity index (VAI), lipid accumulation product (LAP), a body shape index (ABSI) and body roundness index (BRI) were recorded. MetS was defined based on the criteria of the International Diabetes Federation. Participants were categorized into four groups according to quartiles of different obesity indices. Binary logistic regression analyses were used to evaluate the associations between the eight obesity parameters and MetS. Receiver operator curve (ROC) analyses were used to identify the best predictor of MetS. RESULTS: The eight anthropometric obesity indexes were independently associated with MetS risk, even after adjustment for age, sex, educational status and history of smoking. The ROC analysis revealed that all the eight obesity indices included in the study were able to discriminate MetS [all area under the ROC curves (AUCs) > 0.6, P < 0.05]. LAP showed the highest AUC and according to the maximum Youden indexes, the cut off values for men and women were 27.29 and 36.45, respectively. The AUCs of LAP, VAI, ABSI, BRI, WC, WHtR, Ci and BMI were 0.88, 0.87, 0.60, 0.78, 0.79, 0.78, 0.69 and 0.76 for men, and 0.87, 0.85, 0.65, 0.79, 0.81, 0.79, 0.73 and 0.76 for women, respectively. There was no significant difference in the AUC value between LAP and VAI, BRI/WHtR and BMI in men and between BRI/WHtR and BMI in women. The AUC value for WHtR was equal to that for BRI in identifying MetS. CONCLUSIONS: Visceral obesity marker LAP followed by VAI was the most effective predictor of MetS while ABSI followed by CI was the weakest indicator for the screening of MetS in MHD patients. BRI could be an alternative obesity measure to WHtR in assessment of MetS. LAP may be a simple and useful screening tool to identify individuals at high risk of MetS particularly in middle-aged and elderly Chinese MHD patients. LEVEL OF EVIDENCE: Level V, descriptive study.