Biological evaluation of intervertebral disc cells in different formulations of gellan gum‐based hydrogels

Gellan gum (GG)‐based hydrogels are advantageous in tissue engineering not only due to their ability to retain large quantities of water and provide a similar environment to that of natural extracellular matrix (ECM), but also because they can gelify in situ in seconds. Their mechanical properties can be fine‐tuned to mimic natural tissues such as the nucleus pulposus (NP). This study produced different formulations of GG hydrogels by mixing varying amounts of methacrylated (GG‐MA) and high‐acyl gellan gums (HA‐GG) for applications as acellular and cellular NP substitutes. The hydrogels were physicochemically characterized by dynamic mechanical analysis. Degradation and swelling abilities were assessed by soaking in a phosphate buffered saline solution for up to 170 h. Results showed that as HA‐GG content increased, the modulus of the hydrogels decreased. Moreover, increases in HA‐GG content induced greater weight loss in the GG‐MA/HA‐GG formulation compared to GG‐MA hydrogel. Potential cytotoxicity of the hydrogel was assessed by culturing rabbit NP cells up to 7 days. An MTS assay was performed by seeding rabbit NP cells onto the surface of 3D hydrogel disc formulations. Viability of rabbit NP cells encapsulated within the different hydrogel formulations was also evaluated by Calcein‐AM and ATP assays. Results showed that tunable GG‐MA/HA‐GG hydrogels were non‐cytotoxic and supported viability of rabbit NP cells. Copyright © 2012 John Wiley & Sons, Ltd.     

Diabetes and orthopaedic surgery: a review

Diabetes mellitus (DM) is common, estimated to affect 425 million people worldwide in 2017. It is a condition that is continually growing in prevalence and is often associated with multiple co-morbidities. Its multi-system effects on the body mean that its management can pose a challenge, even to more experienced clinicians. In orthopaedic practice, diabetic patients are commonly encountered owing to their increased fracture risk and complications of the disease such as diabetic foot. An appropriate knowledge of diabetes, its pathophysiology, immunology and the pharmacology of medications used in its treatment is essential, as the consequences of mismanagement can be grave. Optimal treatment of diabetics can often require the involvement of a wider multidisciplinary team. Complications that can be encountered in the perioperative and postoperative periods include, diabetic ketoacidosis, hyperosmolar hyperglycaemic state, surgical site infection and venous thromboembolism. This review outlines current concepts in the perioperative management of diabetes and its manifestations within orthopaedic surgery, with a focus on outcomes and complications. A review of the available literature reveals conflicting conclusions between studies, with no clear effect or consensus yet established for many issues. There is a need for a greater number of well-designed, high-quality, appropriately powered trials to establish the true effect of diabetes on outcomes in orthopaedic surgery.     

Importance of catalase in the disposal of hydrogen peroxide within human erythrocytes

The catalase within normal, intact human erythrocytes was completely inactivated with amino triazole. The rate of 14CO2 evolution, when the cells were subsequently incubated with 14C-labeled glucose, provided a measure of the rate at which NADPH was being oxidized by the glutathione peroxidase/reductase system for the disposal of H2O2. This rate was determined in control cells and in catalase-inactivated cells while the cells were exposed to H2O2, which was generated at various constant and predetermined rates by glucose oxidase. The results indicated that catalase handles approximately half of the generated H2O2. The glutathione peroxidase/reductase mechanism accounted for the other half. These results are in agreement with our earlier findings on erythrocytes of a subject with a genetic deficiency of catalase. However, an unexpected result with the present approach was the finding that the increased dependence on the glutathione peroxidase/reductase mechanism did not occur until greater than 98% of the catalase had been inactivated. The latter observation indicates that catalase and the glutathione peroxidase/reductase system function intracellularly in a manner very different from that previously ascribed to them. An explanation of the findings requires that the two methods of H2O2 disposal function in a coordinated way, such as a sequential action in which the glutathione peroxidase/reductase system is the rate-limiting step.     

The 100 most wired 2005: the quality connection

An analysis of this year's Most Wired Survey results shows for the first time that hospitals leading the way in information technology also have better outcomes. They use a wider array of IT tools to address quality, they conduct a larger percentage of clinical transitions via IT, and a larger percentage of their physicians enter orders themselves.     

新缩瞳剂包公藤甲素人工合成研究

包公藤甲素是从包公藤(Erycibe obtusifolia Benth.)茎中提得的一个新莨菪烷生物碱,具有强烈的缩瞳作用,临床用于治疗青光眼。本文报道用合成的6β-乙酰氧基托品酮为原料,经卤代、水解、还原和N-去甲基化等反应合成包甲素(8)。经光谱测定证实8与天然包甲素的结构完全一致。合成品系外消旋体,其作用机理与天然品相同,而强度则减半。     

彩色多普勒超声对移植肾急性排斥反应的评价

目的:肾移植的成功与否关键在于及时发现和正确处理排斥反应。探讨无创伤性形态学和血流动力学检查手段彩色多普勒超声在移植肾急性排斥反应中的作用,为临床评估肾移植效果及移植肾功能提供客观的辅助性数据。方法:选择2004-01/2005-12在南京医科大学附属第一医院、江苏省人民医院行同种异体移植肾患者57例,其中经穿刺活检证实或最后临床诊断为急性移植肾排斥反应者22例,未发生排斥反应等并发症的移植肾功能正常者35例,患者均知情同意。采用Philips EnVisor彩色多普勒超声血流显像仪,对急性排斥反应肾移植患者进行二维超声和彩色多普勒血流显像检测,观察排斥反应患者甲基强的松龙冲击治疗前后移植肾脏的大小、形态结构、肾内血管树分布、血流灌注以及各级动脉血流参数(阻力指数,搏动指数)等指标的变化,并与移植肾功能正常患者进行比较。结果:急性排斥反应组2例患者发生严重并发症死亡,进入结果分析急性排斥反应组20例,移植肾功能正常组35例。①发生急性排斥反应时肾移植患者移植肾体积明显大于肾功能正常组(P<0.01);肾实质增厚,皮髓质界限模糊。给予甲基强的松龙冲击治疗后急性排斥反应组患者肾脏厚径显著小于治疗前(P<0.05);肾实质回声减低,皮髓质交界变清。②发生急性排斥反应时肾移植患者移植肾血流阻力指数、搏动指数均显著高于移植肾功能正常组(P<0.01)。治疗后急性排斥反应组患者肾血流阻力指数、搏动指数均显著低于治疗前(P<0.01),与移植肾功能正常组差异无显著性意义(P>0.05)。结论:彩色多普勒超声作为一种简便、经济的无创性技术,对移植肾血流阻力指数、搏动指数的追踪观察可为临床上评估肾移植效果提供较可靠的客观依据,对移植肾急性排斥反应的早期诊断有较高的评估价值。     

Human influenza A (H5N1) cases, urban areas of People's Republic of China, 2005-2006

We investigated potential sources of infection for 6 confirmed influenza A (H5N1) patients who resided in urban areas of People's Republic of China. None had known exposure to sick poultry or poultry that died from illness, but all had visited wet poultry markets before illness.