半互穿网络法制备有机/无机杂化阴离子交换膜

以1,2-双(三乙氧基硅基)乙烷杂化改性的聚乙烯醇(PVA)为聚合物基底,以溴化聚乙烯亚胺(BPEI)为阳离子聚电解质,采用半互穿网络法制备新型阴离子交换膜.对含水率、离子交换容量及膜的形态进行了考察,并测试了膜的电导率及甲醇渗透率以研究其在直接甲醇燃料电池中的应用.测试结果表明,BPEI质量分数在40％时,PVA与BPEI互容性较好,无明显相分离现象产生.BPEI质量分数为20％的阴离子交换膜具有较好的综合性能,其在30℃下的电导率和甲醇渗透率分别为1.32×10-2 S/cm和7.88×10-7 cm-2·s-1.     

涡虫成体干细胞研究进展

干细胞研究是当代生命科学研究的重点和热点之一,涡虫因具有结构简单、再生速度快、基因与脊椎动物同源性高等特点而成为研究再生的良好动物模型.涡虫的这种再生能力与其体内具有被称为neoblasts的多能干细胞群有关.文中结合近几年的研究成果从neoblasts与涡虫的再生关系、neoblasts的分子标记及研究方法3个方面进行综述,以促进neoblasts的研究.     

Fabrication and biological evaluation of polyether ether ketone(PEEK)/bioceramic composites

The repair of vascularized bone defects represents a significantly clinical challenge, and vascular regeneration is one of the necessary factors to promote bone tissue regeneration. To effectively repair large bone defects, new bone tissue must regenerate with a rich vascular network. Therefore, the development of biomaterials that can promote the regeneration of vascularized bone tissue is currently receiving attention from researchers. In this study, Li–Ca–Si bioceramics (LCS) containing Li, Ca, and Si elements was developed, then LCS was compounded with PEEK to prepare PEEK+10% LCS, PEEK+20% LCS, PEEK+30% LCS, and the effect of LCS-PEEK composite biomaterials on the proliferation and angiogenic ability of human umbilical vascular endothelial cells (HUVECs) further explored by Cell Counting Kit-8 (CCK-8), scanning electron microscope (SEM), quantitative real-time PCR (QPCR), Western Blotting and enzyme linked immunosorbent assay (ELISA). The results showed that HUVECs inoculated on 30%LCS ?+ ?PEEK material exhibited the best proliferation ability. And the adhesion ability of endothelial cells on PEEK gradually increased with the increase of LCS contents. Furthermore, the angiogenic ability of HUVECs on LCS-PEEK composites was examined using QPCR and Western blotting, and the results showed that the expression of angiogenic-related genes and proteins of HUVECs on PEEK composites gradually increased with increasing LCS concentration. These results demonstrated that the angiogenic ability of HUVECs was effectively stimulated by LCS-modified PEEK materials. The present results indicate that the PEEK material can be modified with bioceramics to promote angiogenesis, and this study lay the foundation for the subsequent development of scaffolds that promote vascularized bone tissue regeneration.     

TGF-β1与EGF对肺泡Ⅱ型上皮细胞表型及功能的影响

目的:探讨TGF-β1与EGF对肺泡Ⅱ型上皮细胞(RLE-6TN)的影响。方法:将细胞分成对照(C)、TGF-β1(T)、EGF(E)及TGF-β1+EGF(TE)组。采用相差显微镜观察细胞形态,免疫荧光检测α-SMA表达,W.B检测上皮、间质细胞标记物、MMPs及信号蛋白的表达;流式细胞术检测凋亡情况。结果:T及TE组RLE-6TN发生EMT转变并见间质标记物及MT1-MMP、MMP2表达上调,E组Vimentin、MT1-MMP、MMP2及CD147表达上调;T与E组p-ERK、p-38MAPK及p-Akt表达上调,T组p-Smad2表达上调;T与E组均见凋亡,TE组凋亡加剧。结论:单用EGF不能诱导RLE-6TN发生EMT,合用TGF-β1无协同诱导EMT,却能协同诱导凋亡。TGF-β1诱导EMT时,主要通过EGFR信号通路诱导MMPs表达。     

多瘤病毒的培养特性及血清抗体的检查

多瘤病毒最适宜的培养条件为接种病毒吸附1.5h,培养第4天换液1次,用无牛血清维持液培养12天,其血凝素达高峰。当培养物出现血凝素时,即有细胞内抗原的存在。应用血凝抑制试验(HI)和酶免疫法(EIA)两种方法进行对比性试验,检查实验感染多瘤病毒的10只SPF小鼠和192只普通小鼠血清多瘤病毒抗体的出现,实验结果表明HI较EIA敏感。多瘤病毒存在于我国普通饲养的实验小鼠群中。     

模拟微重力抑制间充质干细胞增殖机制的研究

研究微重力对间充质干细胞增殖影响的潜在机制.用随机定位仪模拟微重力(SMG),培养小鼠骨髓间充质干细胞(BMSCs),检测SMG对BMSCs增殖,细胞骨架,以及对细胞的黏附和增殖重要信号分子表达的影响.结果显示,在SMG下,BMSCs增殖受到抑制;细胞微丝结构和分布异常;细胞形态改变;黏着斑激酶(FAK)表达下降;细胞生长信号分子ERK1/2和Akt的磷酸化水平以及p85β表达下降.结果表明,模拟微重力条件下的细胞骨架改变、细胞黏附性降低和细胞增殖的信号通路相互作用,导致对骨髓间充质干细胞增殖的抑制作用.     

Serglycin – Structure and biology

Serglycin is a proteoglycan found in hematopoietic cells and endothelial cells. It has important functions related to formation of several types of storage granules. In connective tissue mast cells the covalently attached glycosaminoglycan is heparin, whereas mucosal mast cells and activated macrophages contain oversulfated chondroitin sulfate (type E). In mast cells, serglycin interact with histamine, chymase, tryptase and carboxypeptidase, in neutrophils with elastase, in cytotoxic T cells with granzyme B, in endothelial cells with tissue-type plasminogen activator and in macrophages with tumor necrosis factor-α. Serglycin is important for the retention of key inflammatory mediators inside storage granules and secretory vesicles. Serglycin can further modulate the activities of partner molecules in different ways after secretion from activated immune cells, through protection, transport, activation and interactions with substrates or target cells. Serglycin is a proteoglycan with important roles in inflammatory reactions. Received 2 October 2007; received after revision 7 November 2007; accepted 12 November 2007     

NOD-like receptors: Ancient sentinels of the innate immune system

NOD-like receptors (NLRs) comprise a family of cytosolic proteins that have been implicated as ancient cellular sentinels mediating protective immune responses elicited by intracellular pathogens or endogenous danger signals. Genetic variants in NLR genes have been associated with complex chronic inflammatory barrier diseases (e.g. Crohn disease, bronchial asthma). In this review, we focus on the molecular pathophysiology of NLRs in the context of chronic inflammatory diseases and pinpoint recent advances in the evolutionary understanding of NLR biology. We propose that the field of NLRs may serve as a prototype for how a comprehensive understanding of an element of the immunological barrier will eventually lead to the development of targeted diagnostic, therapeutic and/or preventive strategies. Received 29 October 2007; received after revision 10 December 2007; accepted 19 December 2007     

Enhancement of vertebrate cardiogenesis by a lectin from perivitelline fluid of horseshoe crab embryo

Cardiac myocytes are the first cells to differentiate during the development of a vertebrate embryo. A wide variety of molecules take part in various steps in this process. While exploring biologically active molecules from marine sources, we found that a constituent of perivitelline fluid from embryos of the Indian horseshoe crab can enhance growth and differentiation of chick embryonic heart. We have purified the factor and identified the cardiac promoting molecule to be a novel lectin. We show that this molecule influences cardiac development by increasing the number of cells constituting the heart and by modulating the expression of several cardiac development regulatory genes in chick embryos. Using mouse embryonic stem cells we show that the cardiac myocyte-enhancing capacity of this molecule extends to mammals and its effects can be blocked using methylated sugars. This molecule may prove to be an important tool in the study of cardiomyocyte differentiation.