Role of arterial stiffness and endothelial dysfunction on lower limb performance in older adults with type 2 diabetes: A cross-sectional study

AimTo verify whether arterial stiffness and endothelial dysfunction influence lower limb muscle strength and gait speed in older adults with type 2 diabetes mellitus (T2DM).MethodsCross-sectional study including seventy-eight older adults with T2DM (aged 67 ± 6 years and 42 % male). Arterial stiffness was assessed using pulse wave velocity (PWV), while endothelial function was measured by flow-mediated dilation (FMD). Lower limb muscle strength and gait speed were assessed using the 30-second chair stand test (30s-CST) and 10-Meter Walk Test, respectively.ResultsBoth PWV (m/s) and FMD (%) were univariately associated with number of repetitions in 30s-CST and gait speed (P < 0.05). After control for age, sex and body mass index, PWV remained associated with repetitions in 30s-CST (95 % CI: ?0.494 to ?0.054; P = 0.015) and gait speed (95 % CI: ?0.039 to ?0.002; P = 0.031). After adjustments for control variables, T2DM duration and glycemic control, FMD was associated with repetitions in 30s-CST (95 % CI: 0.008 to 0.324; P = 0.039) and gait speed (95 % CI: 0.011 to 0.038; P = 0.001).ConclusionIn older adults with T2DM, both arterial stiffness and endothelial dysfunction are associated with decreased leg muscle strength and slower gait speed.     

Gender difference in association between diabetes mellitus and all-cause mortality in atrial fibrillation patients

ObjectiveThere may be gender difference in correlation of diabetes mellitus (DM) and cardiovascular events. We attempt to investigate whether there is gender-heterogeneity in one-year outcomes of atrial fibrillation (AF) patients with DM or not.MethodsPatients who were diagnosed with AF admitted to the emergency departments in the Chinese AF Multicenter Registry study were enrolled. Basic demographics information, initial Blood Pressure and heart rate, medical histories, and treatments of each patient were collected. Follow-up was carried out with a mean duration of one year. The primary endpoint was all-cause mortality and systemic embolism.ResultsA total of 2016 patients were selected from September 2008 and April 2011. All-cause mortality was significantly higher in male AF patients with DM than those without (21.8 % & 13.6 %, P = 0.014). Cox regression analysis showed that there was an interaction between gender and DM for one-year all-cause mortality (P = 0.049). DM was significantly associated with one-year all-cause mortality regardless of univariate analysis (HR = 1.436, 95%CI:1.079–1.911, P = 0.013) or multivariate analysis (HR = 1.418, 95%CI: 1.059–1.899, P = 0.019). For male patients with AF, DM was significantly associated with one-year all-cause mortality (P = 0.048), but not for female patients with AF (P = 0.362).ConclusionDM was independently associated with one-year all-cause mortality in the entire cohort of AF patients. This association was found mainly in male patients with AF, but not in female patients. DM management programs may need to reflect gender difference.     

儿童晕厥临床诊治研究的发展与未来

儿童晕厥在临床常见,严重影响儿童的身心健康.儿童晕厥诊断关键技术的建立、诊断程序及个体化治疗新策略的提出,显著提高了儿童晕厥的诊治水平.基于研究成果,我国先后制定了多部儿童晕厥诊治指南与专家共识,并在国际期刊颁布了儿童和青少年晕厥指南,充分发挥了中国在国际儿童晕厥诊治领域的引领作用.今后尚需进一步开展儿童晕厥的流行病学研究,优化儿童晕厥预警体系以及干预与预防新策略,进一步推进儿童晕厥事业的发展.     

Purification and characterization of the carbonic anhydrase enzyme from Black Sea trout (Salmo trutta Labrax Coruhensis) kidney and inhibition effects of some metal ions on enzyme activity

In this study, the carbonic anhydrase (CA) enzyme was purified from Black Sea trout (Salmo trutta Labrax Coruhensis) kidney with a specific activity of 603.77 EU/mg and a yield of 35.5% using Sepharose-4B-l-tyrosine- sulphanilamide affinity column chromatography. For determining the enzyme purity and subunit molecular mass, sodiumdodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) was performed and single band was observed. The molecular mass of subunit was found approximately 29.71 kDa. The optimum temperature, activation energy (E_a), activation enthalpy (ΔH) and Q₁₀ values were obtained from Arrhenius plot. K_m and V_max values for p-nitrophenyl acetate of the purified enzyme were calculated from Lineweaver-Burk graphs. In addition, the inhibitory effects of different heavy metal ions (Fe²⁺, Pb²⁺, Co²⁺, Ag⁺ and Cu²⁺) on Black Sea trout kidney tissue CA enzyme activities were investigated by using esterase method under in vitro conditions. The heavy metal concentrations inhibiting 50% of enzyme activity (IC₅₀) were obtained. Finally K_i values and inhibition types were calculated from Lineweaver-Burk graphs.     

Three-dimensional finite element analysis of intramedullary nail with different materials in the treatment of intertrochanteric fractures

Intramedullary nails are the common treatment options for femoral intertrochanteric fractures. However, aseptic loosening is considered to be one of the primary forms of failure that can be caused by the stress shielding between the bone and implants. The matching in mechanical properties of implant and bone is a key issue to prevent this failure. Polyetheretherketone (PEEK) and Function-graded (FG) materials are widely used in clinical because of their excellent mechanical properties. In this study, to investigate the biomechanical behaviors of intramedullary nails made of Ti-6Al-4V alloy, Stainless Steel (SS), PEEK and two FG materials, three-dimensional finite element models of intertrochanteric fracture femur with intramedullary nail were constructed with ABAQUS. The maximum von Mises stress on the femoral fracture surface fixed by PEEK intramedullary nail was the largest, followed by FG intramedullary nail, which help stimulate bone growth and subsequently reduce fracture healing time. Compared with traditional metal intramedullary nails, PEEK and FG implants might increase von Mises stress along the same path in the proximal femur. The results showed that PEEK and FG intramedullary nails obviously changed the stress distributions in the bone and reduced stress shielding. This finding indicated that PEEK and FG intramedullary nails have the potential to become alternatives to the conventional metal intramedullary nails.