BACKGROUND: In according to ISO-10993-4 and GB/T 16886.4, the in vitro hemo-compatibility evaluation on biomaterieisincludes thrombosis, coagulation factors, platelets and platelet functions, hematology and complement system. However, in thecase of China, the in vitro hemo-compatibility evaluations were performed only thrombosis, coagulation factors and plateletattachment, the investigation on evaluation of platelet and complement activations is less reported.OBJECTIVE: To evaluate the effect of polyethylene, polyvinyl chloride and polymethylvinylsiloxane tubes on platelet activation,and establish a useful method to evaluate the effect of tubular materials on platelet activation.METHODS: Tubes of polyethylene, poiyvinyl chlorid and silastic were established by 3.7 mm inner diameter, 3.5 mm externaldiameter, and 35 cm length, respectively. 1 mL blood was injected into the tube of polyethylene, polyvinyl chlorid and silasUc,respectively. The tubes were connected using a two-way tube, shaken at 140 r/min by 30° sloping for 3.5 hours at 37 ℃.Radiolmmunoassay was employed to detect α-granules protein level of platelet poor plasma, while flow cytometry was used todetect the percentage of positive plateiet of o-granules protein and that of activated gp Ⅱb/Ⅲa composite.RESULTS AND CONCLUSION: Radiolmmunoassay showed that o-granules protein level of plateiet poor plasma in thepolyethylene and polyvinyl chlorid tubes was significantly greater than that in the silastic tube (P < 0.05). There were no significantdifferences in o-granules protein between polyethylene and polyvinyl chlorid (P > 0.05). Flow cytometry indicated that percentageof positive platelet of o-granules protein in the polyethylene and polyvinyl chlorid tubes was significantly greater than that in thesilastic tube (P < 0.05); the percentage in the polyethylene tube was significantly greater than that in the polyvinyl chlorid tube (P <0.05). There was no significant differences in the percentage of positive plateiet of activated gp IIb/IIIa composite between thethree materials (P > 0.05). A useful blood-material contact model was established, and it was considered that o-granules protein isan available parameter for evaluating platelet activation. The percentage of positive platelet of o-granules protein determined byflow cytometry was a more sensitive parameter for evaluating platelet activation.

In-vitro test is usually conducted as a preliminary screening test in the evaluation of the haemocompatibility of biomaterials for its short-term consuming, convenience and less expense. The selection of appropriate model for blood-biomaterial interaction, the choice of sensitive and specific parameters, and the minimization of additional blood activation are most important in the in-vitro test. In addition, the time and the style of blood-biomaterial interaction, the choice of sensitive and specific parameters, and the minimization of additional blood activation are most important in the in-vitro test. In addition, the time and the style of blood-biomaterial interaction, the selection of primary reference materials and the shear rate should be considered. In recent years, though great progress has been made in the in-vitro evaluation of haemocompatibility of biomaterials, all these influencing factor should be standardized for more effective evaluation of the haemocompatibility of biomaterials.
Biocompatible Materials ; Evaluation Studies as Topic ; Humans ; Materials Testing ; standards

Hemocompatibility is an important component of biocompatibility; it reflects the degree of interaction between material and blood. Hemocompatibility is multifaceted, so that the material's impact on the blood and the underlying mechanism are very complicated. This article presents a review of researches probing the impact of material on blood via contact activation and plasma protein adsorption; via the platelet activated and the formation of thrombin; via the complement system activated and the activation of leukocytes as well as other mechanisms of hemolysis. The current methods for evaluation and the future trend of development are also introduced.
Biocompatible Materials ; standards ; Blood ; Humans ; Materials Testing ; methods ; Platelet Activation ; Platelet Adhesiveness ; Stress, Mechanical ; Surface Properties ; Thrombin ; analysis

In China, the evaluation of hemocompatibility of biomaterials is limited to hemolysis, coagulation time,and the number and morphology of platelets adhered on biomaterials. The present research, however, is aimed to establish a method for evaluating the function of sheet biomaterials in platelet activation. Platelet activation caused by glass, polyvinyl chloride or polymethylvinylsiloxane sheets was evaluated by measuring alpha-granule membrane protein (GMP-140) in platelet poor plasma, using a reasonable blood-material contact model vibrating at different speed. The result showed that the difference in platelet activation was not significantly different among the three above-mentioned materials at 140r/m or 200r/m. However, when it comes to 230r/m, significant difference was observed among these three groups, with glass > polyvinyl chloride > polymethylvinylsiloxane. But the order was reversed at 270r/m, which may be due to the different interfacial tension of different materials. Therefore, the method is suitable to evaluate platelet activation caused by sheet biomaterials, but an appropriate vibrating speed should be chosen. The interfacial tension plays an important role in the model and should be considered for results assessment.
Biocompatible Materials ; Humans ; Materials Testing ; methods ; Platelet Activation ; Surface Properties

Objective:To investigate the effects and underlying mechanisms of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/NF-κB signaling pathway in human kidney-2(HK-2) cells of hyperuricemic nephropathy.Methods:HK-2 cells were cultured in vitro and randomly divided into control group and experimental group. The experimental group was induced by high uric acid (720 μmol/L) immersion for 48 h to establish a cell model of hyperuricemic nephropathy in vitro and subsequently divided into hyperuricemic group, overexpressed protease activated receptor 2 (PAR2) and knockdown PAR2 group. The expressions of PAR2, PI3K, AKT, NF-κB mRNA were measured by real-time PCR. The expressions of PAR2, PI3K, AKT and NF-κB protein were measured by Western blotting. The expressions of tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1), interleukin-6 (IL-6), pro-interleukin-1β (pro-IL-1β), interleukin-1β (IL-1β) and transforming growth factor-β1 (TGF-β1) were detected by enzyme linked immunosorbent assay (ELISA). Results:(1) Compared with the control group, the expressions of PAR2, PI3K, AKT and NF-κB mRNA and protein in hyperuricemic group were significantly increased (all P<0.05), the expressions of TNF-α, MCP-1, IL-6, pro-IL-1β, IL-1β and TGF-β1 in the supernatant in hyperuricemic group were significantly increased (all P<0.01). (2) Compared with the hyperuricemic group, the expressions of PAR2, PI3K, AKT and NF-κB mRNA and protein in overexpressed PAR2 group were significantly increased (all P<0.05), the expressions of TNF-α, MCP-1, IL-6, IL-1β and TGF-β1 in the supernatant were significantly increased (all P<0.05). (3) Compared with the hyperuricemic group, the expression of PAR2, PI3K, AKT and NF-κB mRNA and protein in knockdown PAR2 group were significantly decreased (all P<0.05), the expressions of IL-6, pro-IL-1β, IL-1β and TGF-β1 in the supernatant were significantly decreased (all P<0.05). Conclusions:In the process of uric acid-induced HK-2 cell damage, uric acid significantly up-regulates the expression of PI3K/AKT/NF-κB signaling pathway by activating PAR2, leading to a marked increase in inflammatory damage. Knocking down PAR2 inhibits the expression of PI3K/AKT/NF-κB signaling pathway, which can effectively reduce the inflammatory damage of HK-2 cells.

Objective To explore the current status and the correlation between learning burnout and family function among undergraduate nursing students in a non-governmental school.Methods A total of 460 undergraduate nursing students in a non-governmental medical school in Changsha were selected as study subjects by convenience sampling from September to October 2016. They were investigated with the learning burnout scale (LBS) and the McMaster family assessment device (FAD).Results The total scores of LBS and FAD of undergraduate nursing students in a non-governmental school were (56.94±9.60) and (137.11±15.80) respectively. The total score of LBS was positively correlated with the total score and the scores of all dimensions of FAD among undergraduate nursing students in a non-governmental school (P<0.01). The influencing factors of learning burnout included grades, whether they acted as a student cadre, attitudes towards nursing speciality, academic record and family function (P<0.05).Conclusions The level of learning burnout has a close correlation with family function in undergraduate nursing students in a non-governmental school. The better the family function is, the less the learning burnout will be. School should strengthen the affective education of students and improve the mental state so as to reduce the learning burnout.

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 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.

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.

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.