Fabrication and characterization of chitosan–collagen crosslinked membranes for corneal tissue engineering

This article describes a chitosan–collagen composite membrane as corneal tissue-engineering biomaterials. The membrane was prepared by dissolving the chitosan into collagen with the weight ratio of 0, 15, 30, 45, 60, and 100%, followed by crosslinked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. Mechanical properties, contact angles, and optical transmittance were determined and compared between chitosan membrane and crosslinking composite membrane. As a result, the optical transparency and mechanical strength of the chitosan–collagen membranes were significantly better than that of the sample of chitosan. In addition, in vitro cell culture studies revealed that the collagen has no negative effect on the cell morphology, viability, and proliferation and possess good biocompatibility. Overall, the dendrimer crosslinked chitosan–collagen composite membranes showed promising properties that suggest that these might be suitable biomaterials for corneal tissue-engineering applications.     

354例胸腺瘤外科治疗的临床分析

目的：分析并探讨影响接受外科治疗的胸腺瘤患者预后的临床、病理等因素。方法：回顾性分析南京医科大学第一附属医院胸外科2008年1—6月收治的胸腺瘤患者354例,评估分析年龄、性别、肿瘤直径、世界卫生组织（World Health Organization,WHO）病理分型、TNM分期、Masaoka?Koga分期、重症肌无力、根治性切除对患者预后的影响。结果：Kaplan?Meier单因素生存分析显示：年龄（P=0.002）、肿瘤直径（P=0.045）、WHO病理分型（P=0.051）、TNM分期（P=0.004）、Masaoka?Koga分期（P < 0.001）、根治性切除（P < 0.001）与患者预后相关。Cox多因素生存分析显示,年龄（P=0.003,危害比：10.151,95%CI：2.239~46.021）、WHO病理分型（P=0.045,危害比：3.376,95%CI：1.030~11.064）、Masaoka?Koga分期（P=0.009,危害比：5.621,95%CI：1.552~20.352）是影响胸腺瘤患者总体生存的独立预后因素。结论：胸腺瘤的早期诊断可以有效提高其外科治疗效果,积极实行根治性切除是改善胸腺瘤患者预后的重要手段,术后准确的病理分析可帮助临床医生预测患者预后。     

肠道微生态与人体疾病相关性研究现状

人类肠道有超过百万亿种微生物,其中包括1000余种已知细菌,这些细菌对肠道微生态具有至关重要的作用。根据已知的微生物与体循环的关系,目前广大学者普遍认为肠道微生态的改变与多种疾病的发生有直接联系。通过总结肠道微生态失衡引发的相关性疾病,引起人们重视,并通过挖掘微生态新靶点,达到缓解、治愈相关疾病的目的。     

TWIK1, a unique background channel with variable ion selectivity

TWIK1 belongs to the family of background K(+) channels with two pore domains. In native and transfected cells, TWIK1 is detected mainly in recycling endosomes. In principal cells in the kidney, TWIK1 gene inactivation leads to the loss of a nonselective cationic conductance, an unexpected effect that was attributed to adaptive regulation of other channels. Here, we show that TWIK1 ion selectivity is modulated by extracellular pH. Although TWIK1 is K(+) selective at neutral pH, it becomes permeable to Na(+) at the acidic pH found in endosomes. Selectivity recovery is slow after restoration of a neutral pH. Such hysteresis makes plausible a role of TWIK1 as a background channel in which selectivity and resulting inhibitory or excitatory influences on cell excitability rely on its recycling rate between internal acidic stores and the plasma membrane. TWIK1(-/-) pancreatic β cells are more polarized than control cells, confirming a depolarizing role of TWIK1 in kidney and pancreatic cells.     

漂白剂对复合树脂的影响

临床上常需要对存在复合树脂修复体的牙进行漂白,或者对漂白后的牙进行复合树脂修复。由于漂白剂具有较强的氧化性及反应活性,在一定程度上影响了复合树脂的性能如微硬度、表面粗糙度等;因此,研究漂白剂对复合树脂的影响有重要的临床意义。本文就漂白剂对复合树脂表面性能、与釉质和牙本质粘接强度、微渗漏、颜色等的影响作一综述。     

Metastatic Crohn's disease. Response to adalimumab dose intensification

Inflammatory bowel disease is accompanied by extraintestinal manifestations in a high percentage of patients. Cutaneous lesions are the second most prevalent of these manifestations, and within these, metastatic Crohn's disease is one of the least common, being the least frequent specific cutaneous manifestation of Crohn's disease. This entity includes cutaneous and subcutaneous lesions with a non-caseating granulomatous appearance on histological analysis identical to that of Crohn's disease. These lesions are not found adjacent to the digestive tract. Due to the low prevalence of these manifestations, conclusive trials on the treatment of choice have not been performed and there is no well-defined therapeutic strategy. Distinct therapies with varying results have been reported. We report the case of a female patient with longstanding and complex Crohn's disease who developed metastatic cutaneous manifestations while receiving adalimumab. The cutaneous manifestations responded well to dose intensification of this drug. A review of the literature is provided.     

Effects of Head and Neck Inclination on Bilateral Sternocleidomastoid EMG Activity in Healthy Subjects and in Patients with Myogenic Cranio-Cervical-Mandibular Dysfunction

This study was conducted in order to determine the effect of head and neck position on bilateral electromyographic (EMG) activity of the sternocleidomastoid muscles. The study was performed on 16 patients with myogenic cranio-cervical-mandibular dysfunction (CMD) and 16 healthy subjects. EMG recordings at rest and during swallowing of saliva and maximal voluntary clenching were performed by placing surface electrodes on the right and left sternocleidomastoid muscles. EMG activity was recorded in the left lateral decubitus position, in a darkened room and with the individual's eyes closed, under the following experimental conditions: 1. Head, neck, and body horizontally aligned; 2. Head and neck upwardly inclined with respect to the body, simulating the effect of a thick pillow, 3. Head and neck downwardly inclined with respect to the body, simulating the effect of a thin pillow. Variation of head and neck positions was determined by measuring the distance from the angle of neck and shoulder and the apex of the shoulder (SND = shoulder—neck distance) of each individual. Then, head and neck were forward or downwardly inclined with respect to the body at one-third of SND. A significantly higher contralateral EMG activity and a more asymmetric EMG activity were observed in the CMD group than in the healthy subjects (Kruskal-Wallis Test).These results suggest a different behavior of bilateral sternocleidomastoid EMG activity in CMD patients than in healthy subjects depending on the positioning of the head and neck.