Effects of tanshinone IIA on endothelial cell dysfunction in uremic condition.

An arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis in uremic patients, yet its dysfunction poses a significant clinical challenge. Venous stenosis, primarily caused by venous neointimal hyperplasia, is a key factor in the failure of vascular access. During vascular access dysfunction, endothelial cells (ECs) transform mechanical stimuli into intracellular signals and interact with vascular smooth muscle cells. Tanshinone IIA, an important compound derived from Salvia miltiorrhiza, has been widely used to treat cardiovascular diseases. However, its role in modulating ECs under uremic conditions remains incompletely understood. In this research, ECs were exposed to sodium tanshinone IIA sulfonate (STS) and subjected to shear stress and uremic conditions. The results indicate that STS can reduce the suppressive effects on the expression of NF-κB p65, JNK and Collagen I in uremia-induced ECs. Moreover, the downregulation of NF-κB p65, JNK and Collagen I can be enhanced through the inhibition of ERK1/2 and the upregulation of Caveolin-1. These findings suggest that tanshinone IIA may improve EC function under uremic conditions by targeting the Caveolin-1/ERK1/2 pathway, presenting tanshinone IIA as a potential therapeutic agent against AVF immaturity caused by EC dysfunction.

Effects of wall shear stress in venous neointimal hyperplasia of arteriovenous fistulae.

AIM: An arteriovenous fistulae (AVF) is the preferred vascular access for maintenance haemodialysis patients. Its dysfunction is often due to venous stenosis, which is mainly caused by neointimal hyperplasia. Additionally, haemodynamic forces, especially wall shear stress (WSS), as a mechanical stimuli to venous wall have a significant role in neointimal hyperplasia. The purpose of this study was to evaluate the association between WSS and neointimal hyperplasia. METHODS: An 'end-to-side' AVF was created between the right femoral artery and vein of canines. Canines were killed at 7 and 28 days post-surgery. The velocity and WSS in the three-dimensional computational model of AVF were simulated using computational fluid dynamics (CFDs). The four typical sites of the vein evaluated in this study, chosen according to the haemodynamic analysis, included the arteriovenous anastomosis (A-V), the juxta-anastomotic segment (J-V), the juxta-ligation segment (L-V) and the proximal vein (P-V). The specimens were haematoxylin-eosin stained and the intima-media thickening was then measured. RESULTS: Neointimal hyperplasia was more obvious in the inner wall of the J-V and L-V (low-and-disturbed WSS) sites compared with the P-V and A-V sites, and the outer wall of the L-V and J-V segments (high or laminar WSS) (P < 0.01). CONCLUSION: In this study, we described the haemodynamic condition in the AVF and found that neointimal hyperplasia predisposed to occur in the inner wall of venous segment near the anastomosis. We also found that not only the neointimal hyperplasia has a strong inverse correlation with WSS levels, but also is related to flow patterns.

Maternal and Placental DNA Methylation Changes Associated with the Pathogenesis of Gestational Diabetes Mellitus.

Gestational diabetes mellitus (GDM) is an important metabolic complication of pregnancy, which affects the future health of both the mother and the newborn. The pathogenesis of GDM is not completely clear, but what is clear is that with the development and growth of the placenta, GDM onset and blood glucose is difficult to control, while gestational diabetes patients' blood glucose drops and reaches normal after placenta delivery. This may be associated with placental secretion of insulin-like growth factor, adipokines, tumor necrosis factor-α, cytokines and insulin resistance. Therefore, endocrine secretion of placenta plays a key role in the pathogenesis of GDM. The influence of DNA methylation of these molecules and pathway-related genes on gene expression is also closely related to the pathogenesis of GDM. Here, this review attempts to clarify the pathogenesis of GDM and the related maternal and placental DNA methylation changes and how they affect metabolic pathways.

Prognostic Value of Systemic Immune-Inflammation Index among Critically Ill Patients with Acute Kidney Injury: A Retrospective Cohort Study.

Inflammation plays a significant role in the occurrence and development of acute kidney injury (AKI). Evidence regarding the prognostic effect of the systemic immune-inflammation index (SII) in critically ill patients with AKI is scarce. The aim of this study was to assess the association between SII and all-cause mortality in these patients. Detailed clinical data were extracted from the Medical Information Mart for Intensive Care Database (MIMIC)-IV. The primary outcome was set as the in-hospital mortality. A total of 10,764 AKI patients were enrolled in this study. The restricted cubic splines analyses showed a J-shaped curve between SII and the risk of in-hospital and ICU mortality. After adjusting for relevant confounders, multivariate Cox regression analysis showed that both lower and higher SII levels were associated with an elevated risk of in-hospital all-cause mortality. A similar trend was observed for ICU mortality. In summary, we found that the SII was associated in a J-shaped pattern with all-cause mortality among critically ill patients with AKI. SII appears to be have potential applications in the clinical setting as a novel and easily accessible biomarker for predicting the prognosis of AKI patients.

Construction of a Three-Dimensional BaTiO3 Network for Enhanced Permittivity and Energy Storage of PVDF Composites.

Three-dimensional BaTiO3 (3D BT)/polyvinylidene fluoride (PVDF) composite dielectrics were fabricated by inversely introducing PVDF solution into a continuous 3D BT network, which was simply constructed via the sol-gel method using a cleanroom wiper as a template. The effect of the 3D BT microstructure and content on the dielectric and energy storage properties of the composites were explored. The results showed that 3D BT with a well-connected continuous network and moderate grain sizes could be easily obtained by calcining a barium source containing a wiper template at 1100 °C for 3 h. The as-fabricated 3D BT/PVDF composites with 21.1 wt% content of 3D BT (3DBT-2) exhibited the best comprehensive dielectric and energy storage performances. An enhanced dielectric constant of 25.3 at 100 Hz, which was 2.8 times higher than that of pure PVDF and 1.4 times superior to the conventional nano-BT/PVDF 25 wt% system, was achieved in addition with a low dielectric loss of 0.057 and a moderate dielectric breakdown strength of 73.8 kV·mm-1. In addition, the composite of 3DBT-2 exhibited the highest discharge energy density of 1.6 × 10-3 J·cm-3 under 3 kV·mm-1, which was nearly 4.5 times higher than that of neat PVDF.

Hydrothermal Synthesis and Multicolor Upconversion Fluorescence of Novel LiLuF4:Yb3+,Tm3+ Microcrystals.

LiLuF4:Yb3+,Tm3+ upconversion luminescence materials were synthesized by a hydrothermal method, in which NaF and NaBF4 were used as fluorine sources (labeled as sample A and B, respectively). Their morphologies, XRD patterns and UC emission properties were compared. The synthesized crystallites consist of regular octahedrons of several micrometers and aggregates. The XRD patterns indicate that they belong to tetragonal crystal system with 141/a space group. These microcrystals emit strong UC violet, visible and near infrared light under the excitation of 980 nm laser diode. The multicolor UC emissions from sample B are much stronger than those from sample A. The strong emission intensity is ascribed to good crystal quality of sample B.

Enhanced Red Upconversion Luminescence in Yb-Er Codoped NaYF4 Nanocrystals.

In this work the effects of NaYF4:Yb,Er (NYE) structure on the enhanced red upconversion luminescence (UC) was investigated. α-NYE nanocrystals (NCs) and ß-NYE NCs were fabricated by a high temperature decomposition reaction method. The prepared NCs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. The results show that the red UC luminescence of α-NYE NCs is significantly enhanced compared with that of ß-NYE. Furthermore, a possible energy transfer mechanism was proposed on the basis of our experimental results.

The Effect of Phase Structures on the Enhanced Red Upconversion Luminescence in NaLuF4:Yb-Er Nanocrystals.

In this work, α-NaLuF4:Yb,Er (NLF) nanocomposites (NCs) and ß-NLF NCs with diameter about ~13 nm were fabricated by a high temperature decomposition reaction method. The effects of NLF structure on the enhanced red upconversion luminescence performance were investigated. Under 980 nm excitation from a laser diode, the α-NLF emitted dominant red UC emission. Furthermore, the possible energy transfer mechanism was proposed on the basis of our experimental results.

Longer duration of catheter patency, but similar infection rates with internal jugular vein versus iliac vein tunneled cuffed hemodialysis catheters: a single-center retrospective analysis.

BACKGROUND: Although tunneled cuffed catheters (TCCs) are widely used in hemodialysis, little is known about their complications in elderly patients with hemodialysis. Furthermore, there is no report about which vessel access, either jugular or iliac vein, is superior for elderly patients requiring TCCs. METHODS: In the present study, we reviewed the clinical parameters of 127 patients aged over 65 years with 207 new TCC placements and measured the incidence of catheter patency, infection, dysfunction, and survival of TCCs. RESULTS: We found that the average primary catheter patency was substantially shorter in iliac vein TCCs than in internal jugular vein TCCs (373 vs. 641 catheter-days). Patients with iliac vein TCCs underwent more frequent exchanges than those with internal jugular vein TCCs. Infection-free survival was similar for both groups (p = 0.748), but dysfunction-free survival was significantly poorer in iliac vein TCC group than that in internal jugular vein TCC group (p = 0.001). Age and previous catheter placement were the independent risk factors for TCCs survival. CONCLUSION: Taken together, our results suggested that iliac vein TCCs present an increased risk of dysfunction compared to internal jugular vein TCCs in elderly hemodialysis patients.

MTHFR gene C677T polymorphism and type 2 diabetic nephropathy in Asian populations: a meta-analysis.

BACKGROUND: Many studies have suggested a correlation between the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene and diabetic nephropathy (DN), but their results are inconclusive. METHODS: To confirm this correlation, we performed a meta-analysis of 15 studies. The dichotomous data are presented as odds ratios (OR) with 95% confidence intervals (CI). RESULTS: The results of this study suggested that the MTHFR 677 T allele was more likely to increase the risk of DN in Asian (OR = 1.466, 95% CI = 1.143-1.880, P = 0.003), West Asian (OR = 1.750, 95% CI = 1.150-2.664, P = 0.009), and Chinese populations (OR = 2.162, 95% CI = 1.719-2.719, P = 0.001), but not in East Asian or Japanese populations. The carriers of the MTHFR 677 T allele were associated with progression of DN in the "5-10 year duration" group, but not in the "> 10 year duration" group (OR = 2.187, 95% CI = 1.787-2.677, P = 0.001). CONCLUSION: Development of DN is associated with MTHFR C677T polymorphisms in Asian populations, especially in early type 2 diabetes.