The stenosis and embolization of internal fistula vessels directly affect the clinical treatment effect of maintenance hemodialysis patients, and the study of the mechanism of internal fistula stenosis has become a research hotspot in recent years. Previous studies mainly focused on the hemodynamics and pathophysiology of blood vessel wall, and there were few studies on molecular biology and its related signaling pathways. This paper reviews the hemodynamics of the vascular pathway of internal arteriovenous fistula (AVF), the pathophysiological mechanism, molecular biology, and changes in various signaling pathways of AVF dysfunction at home and abroad, in order to provide references for the study of AVF dysfunction.

Objective To investigate the relationship between serum levels of vitamin D(VD)and brain derived neurotrophic factor(BDNF)and restless leg syndrome(RLS)in maintenance hemodialysis patients.Methods A total of 168 end-stage renal disease patients admitted to the hospital for maintenance hemodialy-sis treatment from May 2021 to May 2022 were regarded as the observation group.According to whether they had concurrent RLS,they were separated into concurrent RLS group and non concurrent RLS group.In addi-tion,121 healthy volunteers who came to the hospital for physical examination were regarded as the control group.Enzyme-linked immunosorbent assay(ELISA)was applied to detect the levels of VD and BDNF in ser-um,multivariate Logistic regression was applied to analyze the influencing factors of RLS in maintenance he-modialysis patients.Receiver operating characteristic(ROC)curve was plotted to analyze the predictive value of single and combined detections of VD and BDNF for RLS in maintenance hemodialysis patients.Results Compared with the control group,the serum levels of VD and BDNF in the observation group were reduced(P<0.05).Compared with the non concurrent RLS group,the continuous dialysis time and serum ferritin level in the non concurrent RLS group were increased,while serum VD and BDNF levels were reduced(P<0.05).Multivariate Logistic regression analysis showed that VD and BDNF were protective factors for RLS in maintenance hemodialysis patients,while continuous dialysis time and ferritin were risk factors for RLS in maintenance hemodialysis pa-tients(P<0.05).The area under the curve of the combined prediction of VD and BDNF for RLS in mainte-nance hemodialysis patients was 0.889,which was superior to those of single detection(Zcombination-VD=3.748,Zcombination-BDNF=2.245,P<0.05),and the sensitivity of the combined detection was 86.11%,and the specificity was 79.55%.Conclusion The levels of VD and BDNF in serum are protective factors for RLS in maintenance hemodialysis patients.The combination of the two could effectively predict RLS in maintenance hemodialysis patients.

This study aims to establish a rat model of renal ischemia reperfusion injury (RIRI) to observe the alterations in the expression of phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway following various exosome treatments. Additionally, differential miRNA expression analysis will be conducted to elucidate the molecular mechanisms underlying the effects of exosomes derived from ischemic preconditioned (IPC) renal tubular cells in mitigating RIRI in rats. Initially, ten SD rats were subjected to bilateral nephrectomy under general anesthesia to prepare primary renal tubular cells. The second-generation renal tubular cells were then subjected to the following treatments for 12 hours: normoxia (38% O 2, 5% CO 2), hypoxia (1% O 2, 5% CO 2), and hypoxia plus inactivation (heated at 65 ℃ for 30 minutes). Following these treatments, exosomes were extracted, yielding normoxic exosomes, IPC exosomes, and inactivated exosomes, respectively. A subsequent cohort of 50 SD rats was randomly divided into five groups: Sham group, RIRI group, RIRI + normoxic exosome group (NC group), RIRI + IPC exosome group (IPC group), and RIRI + inactivated exosome group (INA group). RIRI model was established in the latter four groups. Twenty-four hours after RIRI modeling, the NC, IPC, and INA groups received intravenous injections of 200 μg of normoxic exosomes, IPC exosomes, and inactivated exosomes via the tail vein, respectively. Six days later, venous blood samples were collected, and both kidneys were excised to observe renal function, histopathological changes in kidney tissue, and alterations in the PI3K/AKT/mTOR signaling pathway among the five groups. Furthermore, differential miRNA expression analysis [ P<0.05, |log 2(Fold Change)|≥1] was conducted between the NC and IPC groups to investigate the changes in the miRNA expression profile. Subsequently, GO analysis and KEGG pathway enrichment analysis were performed. The results revealed that: (1) Compared with the Sham group, the RIRI and INA groups exhibited elevated levels of serum creatinine and urea nitrogen (all P<0.01). Histopathological examination of kidney tissues showed substantial inflammatory cell infiltration in the interstitium accompanied by varying degrees of edema, degenerative swelling of tubular structures, necrosis, and detachment of tubular epithelial cells. Notably, the number of TUNEL-positive cells was significantly increased, while the number of Ki67-stained positive cells was markedly decreased. Additionally, the mRNA and protein expression of PI3K/AKT/mTOR signaling pathway in RIRI group and INA group were down-regulated. (2) Compared to the NC group, the IPC group demonstrated lower levels of serum creatinine and urea nitrogen (both P<0.01). Notably, there was a significant decrease in the accumulation of inflammatory cells in the renal interstitium, and tissue edema was markedly improved. Moreover, the number of TUNEL-positive cells was reduced, while the number of Ki67-stained positive cells was significantly increased. Additionally, the mRNA and protein expressions of PI3K, PDK1, AKT, and mTOR were all up-regulated (all P<0.05). (3) Compared to the NC group, 56 miRNAs were up-regulated and 42 miRNAs were down-regulated in the IPC group. The target genes of GO enrichment analysis were PIK3C2A, PIK3CA, PIK3CB, PIK3CD, PIK3C2G, AKT1, mTOR, Rheb, and KEGG enrichment analysis revealed significant enrichment in PI3K/AKT signal pathway and mTOR signal pathway. In conclusion, this study reveals that during the course of RIRI, exosomes derived from IPC renal tubular cells induce differential miRNA expression in kidney tissues, resulting in enhanced expression of the PI3K/AKT/mTOR signaling pathway, which plays a pivotal role in mitigating RIRI in rats.

Objective:Clamping bilateral renal arteries with refined surgical methods to establish the rat renal ischemia-reperfusion injury (RIRI) model, and study the protective mechanism of ischemic preconditioning renal (IPC) tubular cell-derived exosomes in RIRI.Methods:25 female Sprague Dawley (SD) rats were divided into sham group, model group, inactivated group, normoxic group, IPC group. In the sham operation group, after bilateral renal arteries were dissociated, the back incision was disinfected and closed. The model group established RIRI model; RIRI models were established in inactivated group, normoxia group and IPC group, and then 200 μg of inactivated exosomes, normal exosomes and IPC exosomes were injected into the caudal vein 24 hours after operation. Serum creatinine (Scr) and urea nitrogen (BUN) levels were detected. The pathological changes of renal tissue were observed under light microscope. Transmission electron microscopy (TEM) was used to observe the shape and size of renal tubular exosomes. Nanoparticle tracking analysis (NTA)was used to detect the concentration and size of renal tubular exosomes.Results:Compared with the sham group, the Scr and BUN levels in the model group were significantly elevated ( P<0.01). Renal pathological changes in the model group showed damaged of the tubular structure, necrosis and shedding of tubular epithelial cells, and a large number of inflammatory cells accumulated in the renal interstitial tissue with varying degrees of edema. Compared with the inactivated group, the Scr and BUN levels significantly decreased in the normoxic group and IPC group ( P<0.01). Renal pathological changes in the normoxic group and IPC group showed that the renal tubular cell necrosis alleviated, inflammatory was reduced, the improved edema. Compared with the normoxic group, the Scr and BUN levels in the IPC group were further reduced ( P<0.01). Renal pathological changes in the IPC group showed that the inflammatory cells were significantly reduced, the cell edema was significantly improved, and the cell apoptosis was significantly reduced. Conclusions:Clamping bilateral renal arteries with refined surgical methods is the main and optimal way to build a rat model of RIRI. IPC tubular cell-derived exosomes have protective and repair effects on RIRI.

Objective:To establish a mouse model of intra-jugular arteriovenous fistula (AVF) to screen differentially expressed genes in the process of intimal stenosis of AVF for investigating the abnormal expression signaling pathways and the mechanisms.Methods:Forty-six male C57BL/6 mice were randomly divided into AVF group ( n=23) and sham-operated group ( n=23). The AVF group underwent internal jugular arteriovenous fistuloplasty, and the sham-operated group separated the right external jugular vein and common carotid artery and then sutured the incision. The whole-genome sequences of mice with AVF stenosis were determined by transcriptomic reversible chain terminator and synthetic sequencing. The microarray data set was established, and the Benjamini & Hochberg method of gene microarray data analysis was applied to screen the differentially expressed genes. The differentially expressed genes were screened by R-language enrichment analysis. Then, gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) were performed. The subcellular localization of the differentially expressed genes was performed by BUSCA software. The protein network interaction of differentially expressed genes was analyzed by using STRING database and Cytoscape software. Results:In the AVF group, 21 mice were successfully modeled and 2 mice failed. Therefore, there were 21 mice in the AVF group and only 21 mice in the sham-operated group. This mouse internal jugular AVF model was innovated using the continuous-interrupted suture method, which improved the success rate of modeling this model. The differential gene sequencing analysis showed that there were 2 514 differentially expressed genes in the AVF process, including 1 323 up-regulated genes and 1 191 down-regulated genes. GO functional enrichment analysis showed that the differential genes were mainly enriched in metabolic process, activation, redox, mitochondria and so on. KEGG pathway enrichment analysis showed that the differential genes were enriched in metabolism, energy substance synthesis, diabetes, oxidative stress and so on. Statistical analysis of subcellular localization showed that the differences were mainly in mitochondrial proteins (24.24%), cytoplasmic proteins (17.51%), nuclear proteins (13.13%), cell membrane proteins (11.45%), and extracellular proteins (10.77%).Conclusions:Mitochondrial oxidative stress injury may be involved in the pathological damage process of endothelial proliferation stenosis in the AVF.

Objective:To study the clinical effect of vacuum sealing drainage in the treatment of chronic traumatic subcutaneous hematoma.Methods:Patients of chronic traumatic subcutaneous hematoma who were admitted to the Department of Burns and Plastic Surgery of Jiaozhou Central Hospital of Qingdao from June 2018 to June 2021 were included and randomly divided into the control group and the experimental group according to the random number table method. The subcutaneous hematoma was incised for debridement, and the blood clots, exudates, necrotic tissues, and pseudosynovium in the cavity were removed. The control group was treated with vaseline oil gauze filling drainage and dressing change method, and the experimental group was treated with vacuum sealing drainage and dressing change method. During the treatment, the closing time of subcutaneous hematoma cavity was observed and compared between the two groups.Results:A total of 42 patients with chronic traumatic subcutaneous hematoma were enrolled, 21 in the control group and 21 in the experimental group, including 11 males and 10 females in the control group, aged (46.2±12.4) years; 13 males and 8 females in the experimental group, aged (44.3±10.6) years. After treatment, all the subcutaneous hematoma spaces were closed in the 42 patients. The closing time of subcutaneous hematoma cavity in the experimental group was (15.52±1.69) days, which was significantly shorter than that in the control group (24.14±2.57) days. There was a significant difference between the two groups ( P<0.01). Conclusions:After incision and debridement of chronic traumatic subcutaneous hematoma, vacuum sealing drainage and dressing change can actively and fully drain the exudate in the cavity, residual blood clots, necrotic tissues, and pseudosynovium, promote the growth of new granulation tissue, which is more conducive to the closure of the cavity of subcutaneous hematoma, and shorten the clinical treatment cycle.

Objective:To study the clinical effect of vacuum sealing drainage in the treatment of chronic traumatic subcutaneous hematoma.Methods:Patients of chronic traumatic subcutaneous hematoma who were admitted to the Department of Burns and Plastic Surgery of Jiaozhou Central Hospital of Qingdao from June 2018 to June 2021 were included and randomly divided into the control group and the experimental group according to the random number table method. The subcutaneous hematoma was incised for debridement, and the blood clots, exudates, necrotic tissues, and pseudosynovium in the cavity were removed. The control group was treated with vaseline oil gauze filling drainage and dressing change method, and the experimental group was treated with vacuum sealing drainage and dressing change method. During the treatment, the closing time of subcutaneous hematoma cavity was observed and compared between the two groups.Results:A total of 42 patients with chronic traumatic subcutaneous hematoma were enrolled, 21 in the control group and 21 in the experimental group, including 11 males and 10 females in the control group, aged (46.2±12.4) years; 13 males and 8 females in the experimental group, aged (44.3±10.6) years. After treatment, all the subcutaneous hematoma spaces were closed in the 42 patients. The closing time of subcutaneous hematoma cavity in the experimental group was (15.52±1.69) days, which was significantly shorter than that in the control group (24.14±2.57) days. There was a significant difference between the two groups ( P<0.01). Conclusions:After incision and debridement of chronic traumatic subcutaneous hematoma, vacuum sealing drainage and dressing change can actively and fully drain the exudate in the cavity, residual blood clots, necrotic tissues, and pseudosynovium, promote the growth of new granulation tissue, which is more conducive to the closure of the cavity of subcutaneous hematoma, and shorten the clinical treatment cycle.

Objective: To evaluate the outcome of negative pressure closed drainage with chitosan membrane in the treatment of multiple drug-resistant bacterial infections. Methods: From January 2015 to December 2017, 108 patients with skin ulcer wound complicated by multiple drug-resistant bacterial infection were admitted in the department of burn and plastic surgery, Qingdao Jiaozhou Central Hospital. Among them, 36 patients had pressure ulcers, 40 cases had diabetic foot wounds, and 32 were traumatic skin ulcer wounds. Patients were divided into group A or group B for different treatments. In group A, besides the basic surgical dressing change, patients were treated by negative pressure closed drainage with chitosan membrane. The patients in Group B were only treated with basic surgical dressing change. The changes of wound were closely observed during the phases, and the wound bacterial culture and antimicrobial drug sensitivity test were performed regularly. The therapeutic effects of the 2 groups were compared. The changes of bacterial species of wound infection and the healing time were recorded. Results: In group A, the healing time of wound infection was: pressure ulcers (14.00±1.28) days, diabetic foot wounds (13.40±1.27) days, traumatic skin ulcer wounds (12.44±1.55) days. In group B, the wound healing time was: pressure ulcers (25.17±2.73) days, diabetic foot wounds (23.85±1.73) days, traumatic skin ulcer wounds (19.81±1.94) days. The wound healing time of group A was shorter than group B. In group A, the multiple drug-resistant bacteria was replaced by non-multiple drug-resistant bacteria, or there was no pathogenic bacterial growth. The differences between the two groups was statistically significant (all P<0.05). Conclusions Additional to the basic surgical dressing change, negative pressure closed drainage with chitosan membrane could promote wound healing, when it′s associated with multiple drug-resistant bacteria infection. This method has benefits in efficient drainage, preventing the formation of bacterial biofilm and changing local microenvironment for the dominant propagation. Therefore, it could effectively control the multiple drug-resistant bacterial infections, promote wound healing and save treatment time.

Objective To observe the level of CD4+CD25+ regulatory T cells (CD4+CD25+ Treg cells) with positive fork head transcription factor 3 (Foxp3) and changes of T-box transcription factor TBX1 (TBX1) and myocyte specific enhancer 2D (MEF2D) expression in peripheral blood of rats with acute rejection after renal transplantation,and to investigate its regulatory mechanisms by combined with renal function,plasma interleukin-10 (IL-10),interferon-γ (IFN-γ) and renal histopathological changes.Methods Rat renal transplantation model was established and divided into two groups:acute rejection group (AR group) and non-acute rejection group (non-AR group).Their renal function including serum creatinine (Scr) and blood urea nitrogen (BUN) in plasma was measured.The renal histopathology was observed by HE staining.Levels of IL-10 and IFN-γ in plasma were detected by ELISA.The proportion of CD4+CD25+ Treg cells was measured by flow cytometry.The mRNA expressions of Foxp3,TBX1 and MEF2D in CD4+CD4+Treg cells were detected by real-time PCR,and their protein expressions were tested by Western blotting.Results Compared with these in the non-AR group,the levels of BUN,Scr and IFN-γ significantly increased in AR group (all P ＜ 0.05),while IL-10 decreased (P ＜ 0.05).Renal histopathology in the acute rejection group showed glomerular hypertrophy and mesangial cell proliferation,capillary proliferation and neutrophil infiltration;renal interstitial edema and tubular necrosis,accompanied by lymphocytes,plasma cells and neutrophils infiltration.Compared with that in the non-AR group,the percentage of CD4+CD25+ Treg cells in peripheral blood was notably lowered in AR group (4.50％±0.50％ vs 5.74％±1.96％,P ＜ 0.05).The mRNA and protein expressions of Foxp3 and MEF2D were lower in AR group than those in non-AR group,while the expressions of TBX1 was elevated (all P ＜ 0.05).Conclusions In rats with acute renal allograft rejection,the percentage of CD4+CD25+ Treg cells and expressions of Foxp3,MEF2D and IL-10 decrease,while the expressions of TBX1 and IFN-γ enhance.These participate in the development of acute rejection after renal transplantation,and aggravate the renal damage.

Objective To observe the clinical effect of single urokinase and urokinase pump combined with low-molecular-weight Heparin in the treatment of autogenous arteriovenous fistula thrombolysis,and the influence on inflammatory factors [interleukin (IL)-1,IL-6,tumor necrosis factor-α (TNF-α)] and CD62p.Methods 20 hemodialysis patients hospitalized in our hospital for the treatment of thrombosis in fistula were selected.They were randomly divided into group A (n =10) and group B (n =10).The group A was treated by urokinase infusion,and the group B was treated with urokinase pump combined with low-molecular heparin respectively.Results Compared with that before thrombolysis,the blood flow rate was increased significantly while the IL-1,TNF-oα and CD62p decreased significantly in the two groups after thrombolytic treatment,with statistically significant difference (P ＜ 0.05).Compared with the group A,the IL-1,IL-6 and CD62p in group B were decreased after thrombolytic therapy,with statistically significant difference (P ＜ 0.05).Conclusions Urokinase combined with low-molecular-weight heparin is better than single urokinase in the treatment of arteriovenous fistula thrombolysis,providing a theoretical basis for clinical fistula thrombolysis treatment.