Novel Sulfated Glucomannan-Barium-Alginate Microcapsules in Islet Transplantation: Significantly Decreased the Secretion of Monocyte Chemotactic Protein 1 and Improved the Activity of Islet in Rats

The sulfated glucomannan can be used to filter the heparin-binding properties of cytokines. In this study, novel sulfated glucomannan-barium-alginate (SGA) microcapsules were prepared to encapsulate islets with barium-alginate (ABa) and calcium alginate-poly-l-lysine (APA) microcapsules as controls. SD rat islets were purified as donor cells to Lewis rats that had been treated with streptozotocin. Intraperitoneal transplantation was performed with about 3000 islet equivalent (IEQ) rat. At week three after transplantation, the concentrations of monocyte chemotactic protein-1 (MCP-1), interleukin (IL)-1 β, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α in intraperitoneal fluid were determined using ELISA. At week 8, the islet cell mass in the abdominal microcapsules was excised to test insulin release. The EB-FDA fluorescence staining method was used to observe the functional activity of the islet cells. Compared with ABa and APA microcapsules, SGA microcapsules showed significantly decreased MCP-1 secretion by β-cells. Also, the concentrations of cytokines IL-1β, IFN-γ, and TNF-α were decreased significantly. The activity of the transplanted islets was significantly improved in SGA microcapsules, which shielded against cytokines better than ABa or APA microcapsules and may serve as novel method.     

电压依赖性钙通道与β细胞功能

电压依赖性钙通道(VDCC)是生物体内一大类钙通道,随着膜电位的改变而出现通道的开放、关闭和失活,调节细胞内Ca2+浓度,最终产生生物学效应。其亚型结构各异,在胰腺、心、脑、肾上腺、视网膜及神经等组织器官均有不同程度的分布。VDCC存在的普遍性决定了其作用的广泛性。在胰腺β细胞上,VDCC亚型包括L-型钙通道和非L-型钙通道,对β细胞的钙电流均有贡献,且都参与了胰岛素的分泌过程,对胰岛素的分泌时相起调控作用。因此,了解β细胞中VDCC不同亚型的特点、分布及生物学作用,对阐明糖尿病的发病机制、寻找有效的治疗策略具有重要意义。     

食管穿孔急诊处理原则及治疗方式的探讨

目的：探讨食管穿孔外科急诊处理原则、把握最佳治疗时机及选择合理的治疗方式。方法：回顾总结分析厦门大学附属中山医院胸外科和华中科技大学同济医学院附属协和医院胸外科1997年3月-2008年3月外科治疗食管穿孔33例。治疗禁食观察1例;单纯食管修补4例;食管修补加纵隔胸腔引流6例;食管修补加带蒂大网膜填塞包绕2例;空肠双管造瘘加纵隔胸腔引流13例;食管切除胃食管吻合水3例（其中1例为食管修补失败者）;置入食管支架1例;食管气管瘘切除修补1例;食管瘘口修补并肺叶切除1例;食管-主动脉瘘放弃治疗1例。结果：治愈23例,好转8例,死亡2例。结论：食管破裂穿孔急诊处理原则是闭合瘘口、控制感染、营养支持,其治疗方式根据食管穿孔时间、原因、部位、纵隔及胸腔感染等具体情况选择合理、有效、个体化的治疗方式。     

Semi-conducting properties of titanium dioxide surfaces on titanium implants

The properties of the TiO₂ layer on titanium implant surfaces are decisive for good contact with the surrounding tissue. The oxide properties can be deliberately changed by for example chemical etching, ion incorporation or anodisation. In the present study impedance spectroscopy was used to study the semi-conducting properties of the naturally formed oxide for different pre-treatment of the surface. A turned surface was used as a reference and both physical (blasting) and chemical (hydrofluoric acid etching) treatments were investigated. Blasting of a titanium sample introduces defects in the metal surface and the study clearly shows that also the oxide layer contains defects leading to a higher number of charge carriers (increased conductivity) compared with the oxide on the turned surface. The hydrofluoric acid etching of the blasted surface results in an oxide film with even higher conductivity. Indication of the defect oxide structure for fluoride treated samples was also seen when analysing the TiO⁺/Ti⁺ ratio from ToF-SIMS data. The lowest value of this ratio was obtained for the HF etched sample, indicating a less stoichiometric oxide compared to the other surfaces. This is a result of incorporation of fluoride ions in the oxide, as proven by adsorption studies on a TiO₂ suspension. The results were treated in the context of surface complexation and two surface complexes were identified. Our results are discussed in relation to pull-out data on rabbit. The pull-out forces depend primarily on surface roughness but the contribution from the hydrofluoric acid etching might be explained by fluoride ion incorporation and the resulting increase in oxide conductivity.     

The effect of mesoporous bioactive glass on the physiochemical,biological and drug-release properties of poly(dl-lactide-co-glycolide) films

Poly(lactide-co-glycolide) (PLGA) has been widely used for bone tissue regeneration. However, it lacks hydrophilicity, bioactivity and sufficient mechanical strength and its acidic degradation by-products can lead to pH decrease in the vicinity of the implants. Mesoporous bioactive glass (MBG) with highly ordered structure (pore size 2–50 nm) possesses higher bioactivity than non-mesoporous bioactive glass (BG). The aim of this study is to investigate the effect of MBG on the mechanical strength, in vitro degradation, bioactivity, cellular response and drug release of PLGA films and optimize their physicochemical, biological and drug-delivery properties for bone tissue engineering application. The surface and inner microstructure, mechanical strength and surface hydrophilicity of MBG/PLGA and BG/PLGA films were tested. Results indicated that MBG or BG was uniformly dispersed in the PLGA films. The incorporation of MBG into PLGA films significantly improved their tensile strength, modulus and surface hydrophilicity. MBG/PLGA resulted in an enhanced mechanical strength, in vitro degradation (water absorbance, weight loss and ions release), apatite-formation ability and pH stability in simulated body fluids (SBF), compared to BG/PLGA. MBG/PLGA and BG/PLGA films enhanced human osteoblastic-like cells (HOBs) attachment, spreading and proliferation compared to PLGA. HOBs differentiation was significantly upregulated when cells were cultured on 30 MBG/PLGA for 14 days, compared to 30 BG/PLGA. MBG/PLGA enhanced the accumulative release of dexamethazone (DEX) at early stages (0–200 h) compared to BG/PLGA, however, after 200 h, DEX-release rates for MBG/PLGA was slower than that of BG/PLGA. The contents of MBG in PLGA films can control the amount of DEX released. Taken together, MBG/PLGA films possessed excellent physicochemical, biological and drug-release properties, indicating their potential application for bone tissue engineering by designing 3D scaffolds according to their corresponding compositions.     

A multicentre study assessing the prevalence of sensitizations in patients with asthma and/or rhinitis in China

Background: The prevalence of sensitization in patients with asthma and rhinitis in mainland China remains unclear. Objective: Our aim was to estimate the prevalence of allergy in patients with respiratory allergic diseases such as asthma and/or rhinitis attending respiratory clinics within mainland China. The study also investigated regional and annual differences in the prevalence and pattern of sensitization among the patients in China. Method: A cross‐sectional survey was performed in 6304 patients suffering from asthma and/or rhinitis in 17 cities from 4 regions of China. Patients completed a standardized questionnaire asking for the presence of respiratory and allergic symptoms. They also underwent skin prick tests with 13 common aeroallergens. Results: Among the 6304 patients, 4545 (72.1%) had at least one positive skin prick reaction. The overall prevalence of positive skin prick responses was 59.0% for Dermatophagoides farinae, 57.6% for Dermatophagoides pteronyssinus, 40.7% for Blomia tropicalis, 16.1% for American cockroach, 14.0% for dog, 11.5% for Blatella germanica, 11.3% for Artemisia vulgaris, 10.3% for cat, 6.5% for Ambrosia artemisifolia, 6.3% for mixed mould I, 4.4% for mixed mould IV, 3.5% for mixed grass pollen and 2.2% for mixed tree pollen. Sensitizations to common allergens varied widely between geographical areas and demonstrated unique pattern in patients by stratification with age groups, with asthma and/or rhinitis. Severity of rhinitis and asthma was significantly correlated with skin index of reactivity to Artemisia vulgaris, Ambrosia artemisifolia and to D. pteronyssinus, D. farinae and Blomia tropicalis respectively (P < 0.001). Positive reactivity to the tested allergens and concomitant reactivity to multiple allergens including to house dust mites and Blomia tropicalis was markedly increased in patients with both asthma and rhinitis. Conclusion: House dust mites were the most prevalent allergens in patients with asthma and/or rhinitis in China. There were significant differences in patterns of sensitizations in patients from different geographical areas, age groups as well as asthma and/or rhinitis.     

丙氨酰谷氨酰胺二肽对人脐静脉内皮细胞ECV304缺氧缺糖损伤的保护作用

目的观察丙氨酰谷氨酰胺二肽（丙谷二肽）对人脐静脉内皮细胞ECV304缺氧缺糖损伤的保护作用,并探讨其可能的作用机制。方法在以低氧低糖培养人脐静脉内皮细胞ECV304为细胞损伤模型的基础上,以噻唑蓝（MTT）比色法优化丙谷二肽的最佳作用浓度,显微镜观察细胞形态变化,流式细胞术检测线粒体膜电位。自动生化分析仪测定乳酸脱氢酶（LDH）活性,比色法检测谷胱甘肽（GSH）、丙二醛（MDA）的浓度,RT-PCR方法检测细胞内肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）、热休克蛋白70（HSP70）、葡萄糖调节蛋白78（GRP78）和缺氧诱导因子-1α（HIF-1α）mRNA的表达。结果丙谷二肽能够使细胞在缺氧缺糖应激下存活率增加,线粒体损伤减轻,LDH分泌降低,GSH产生增加,HSP70和HIF-1α mRNA的表达增加。结论丙谷二肽对细胞缺氧缺糖损伤有明显的保护作用,这种保护作用可能与保护线粒体、维持细胞膜结构完整、上调细胞中应激基因HSP70和HIF-1α的表达有关。     

经胃造口逆向植入支架治疗食管癌性狭窄和瘘2例报道

目的方法结果结论探讨经过胃手术造口途径逆向置放食管支架治疗食管瘘的可行眭。使用手术腹壁胃造口途径经由贲门至食管逆向操作,反向置入食管被膜支架以治疗食管癌性狭窄和瘘。二例晚期食管癌患者因食管严重狭窄迂曲,引导钢丝不能经口顺向通过病变段,导致采用常规方法无法置放食管支架;后改经手术胃造口途径逆向植入食管被膜支架均获得成功,食管瘘口被完全封堵,食管狭窄解除,恢复经口进食。其中一例因高龄及原先吸入胜肺炎无法控制终至呼吸衰竭而死亡,另一例存活一年后因癌转移而死亡。经手术胃造口逆向植入食管支架方式治疗复杂食管癌性狭窄和瘘切实可行,但需要积极尽早实施方能收到最佳疗效。