左心辅助泵内皮细胞化的实验研究

培养了猪主动脉血管内皮细胞，用预衬细胞外基质结合作用ｂＦＧＦ的方法实现静置条件下ＰＵ材料的内皮细胞化，并观察内皮化材料在ＬＶＡＰ泵腔内模拟流体条件下内皮细胞的贴壁率和丢失率以及细胞形态变化。结果显示：用预衬基质结合使用ｂＦＧＦ的方法，静置条件下可以实现ＰＵ材料内皮化，镜下观察细胞形态良好，在ＬＶＡＰ泵腔内模拟流体条件下中１和２ｈ后，细胞贴壁率７４．４２％和５９．７０％，丢失率分别为２５．５８％和４     

产胞外脂肪酶菌株的筛选及底物测定

文中采用简便快速的平板检测法，通过观察培养基上生长的菌落直径和其水解圈直径的大小，进行初筛。再用液体培养，采用滴定法测定酶活性，进行复筛筛选出１０株优良菌株。活性最高为４．４５×１０－８ｍｏｌ／ｓ，其中Ｄ６菌株以苏籽油、亚麻油和月见草油为底物，酶活性分别达到１４．２９×１０－８ｍｏｌ／ｓ，１０．９０×１０－８ｍｏｌ／ｓ和１１．３５×１０－８ｍｏｌ／ｓ。     

铜绿微囊藻对UV-B的适应及其种内差异

 在人工UV-B辐照下培养铜绿微囊藻的3个单细胞纯种株系(FACHB905,FACHB85,FACHB69),结果发现:UV-B辐射下藻细胞数目和叶绿素a含量下降,而细胞干重和胞内外多糖含量上升,水溶性和脂溶性色素的吸收光谱改变;铜绿微囊藻对UV-B的适应存在种内差异.     

金色链霉菌代谢与胞外多糖降解消耗耦联效应的研究

以淀粉为主要碳源的金色链霉菌发酵过程中 ,研究了细胞分泌的淀粉酶的淀粉降解产物 .二糖是淀粉酶的主要产物 .发酵过程中 ,胞外淀粉酶的活性同细胞的生长耦合 ,在对数生长期 ,酶活和细胞的笔生长速率达到最大 ,分别为 0 .12g·L- 1 ·min- 1 、2 .4g·L- 1 ·h- 1 .胞外多糖浓度对淀粉酶活力、酶降解产物金霉素合成速度为明显影响     

Platelet-derived growth factor receptor-β in myocyte was upregulated by angiotensin Ⅱ

To observe the regulation of platelet-derived growth factor (PDGF) receptor-βin myocyte stimulated by angiotensin II (AngII) at both integrated and cellular levels and reveal the signal transduction mechanism in cell, two kidneys, one clip (2K1C) renal hypertension were performed by placing a sliver clip around the left renal artery. Blood pressure and the ratio of left ventricular weight to body weight were measured at 4 and 8 weeks after operation. The content of AngII in heart was detected by radioimmunology assay; the protein level of PDGF receptor-βin heart was measured by Western blot analysis. The alteration of PDGF receptor-βstimulated by AngII and several inhibitors was observed on cultured neonatal rat ventricular myocyte (NRVM). The content of AngII in heart of 2K1C renal hypertensive rat at 4 and 8 weeks after operation was increased. Compared with sham group, 4 and 8 weeks after operation, PDGF receptor-βin heart of 2K1C group was upregulated by 100.3% and 127.1% (P < 0.05), respectively. This upregulation could be inhibited by captopril. For cultured myocyte, PDGF receptor-βwas increased by 47.1% after being stimulated by AngII and this upregulation could be inhibited by losartan which was an inhibitor of AT1 receptor. PLC inhibitor (U73122) and MEK inhibitor (PD98059) could partly inhibit PDGF receptor-βupregulation induced by AngII. These results suggested that AngII could upregulate PDGF receptor-βin myocyte by its AT1 receptor and this effect was at least partly dependent on PLC and extracellular signal-regulated kinase (ERK).     

青枯菌胞外多糖和酶对花生细胞POD及CYT的影响

用野生型青枯菌(fy7)及其胞外多糖缺失型(APT)和胞外蛋白缺失型(DF7)分别作用于青枯菌易感花生品种鄂花4号和抗性品种中花2号的悬浮培养细胞,等电聚焦分析处理后的花生细胞的过氧化物酶(POD)、酯酶(FAST)和细胞色素氧化酶(CYT)的变化．与对照组相比,fy7诱导12h时鄂花4号的3种酶都有变化,24h时只有中花2号有新POD带出现．APT诱导12h时只有FAST有变化,24h时POD和cYT均有较显著变化．DP7诱导12h时只有FAST有变化,24h时只有抗性细胞有新POD带出现．     

Sulfatide-tenascin interaction mediates binding to the extracellular matrix and endocytic uptake of liposomes in glioma cells

Tenascin-C is an extracellular matrix glycoprotein, whose expression is highly restricted in normal adult tissues, but markedly up-regulated in a range of tumors, and therefore serves as a potential receptor for targeted anticancer drug or gene delivery. We describe here a liposomal carrier system in which the targeting ligand is sulfatide. Experiments with tenascin-C-expressing glioma cells demonstrated that binding of liposomes to the extracellular matrix relied essentially on the sulfatide-tenascin-C interaction. Following binding to the extracellular matrix, the sulfatide-containing liposomes were internalized via both caveolae/lipid raft- and clathrin-dependent pathways, which would ensure direct cytoplasmic release of the cargoes carried in the liposomes. Such natural lipid-guided intracellular delivery targeting at the extracellular matrix glycoproteins of tumor cells thus opens a new direction for development of more effective anticancer chemotherapeutics in future. K. Shao & Q. Hou: These authors contributed equally to this work. Received 22 September 2006; received after revision 5 December 2006; accepted 9 January 2007     

Enhanced Biological Phosphorus Removal in Anaerobic/Aerobic Sequencing Batch Reactor Supplied with Glucose as Carbon Source

Phosphorus removal performance in an aerobic/aerobic sequencing batch reactor （SBR） supplied with glucose as carbon source was investigated. It was found that there was no phosphate release concomitant with the storing of poly-β-hydroxyalkanoate （PHA） during the anaerobic phase. Whereas, glycogen was soon built up followed by rapid consumption, at the same time, glucose was depleted rapidly. Based on the analysis of different fractions of phosphorus in activated sludge, the relative ratio of organically bound phosphorus in sludge changed at the end of anaerobic and aerobic phases. The ratios were 45.3% and 51.8% respectively. This showed that the polyphosphate broke down during the anaerobic phase to supply part of energy for PHA synthesis. The reason why there was no phosphate release might be the biosorption effect of extracellular exopolymers （EPS）. It was also proved by the analysis of EPS with scanning electron microscopy （SEM） combined with energy dispersive spectrometry （EDS）. The phosphorus weight percentage of EPS at the end of anaerobic phase was 9.22%.     

Matrix metalloproteinase 19 processes the laminin 5 gamma 2 chain and induces epithelial cell migration

In this study we analyzed the proteolytic activity of MMP-19 and its impact on keratinocyte migration. In the HaCaT keratinocyte cell line overexpressing wild-type MMP-19 (HaCaT-WT), transmigration through fibrin and type IV collagen matrices was significantly increased compared to cells harboring a catalytically inactive mutant (HaCaT-EA). Studying the expression of MMP-19 in early stages of squamous cell cancer (SCC), we found co-localization of MMP-19 and laminin 5 at the invading tumor front but not in suprabasal epidermis of the tumor. Examination of laminin 5 processing revealed increased processing of the 2 chain in the medium and matrix of HaCaT-WT cells and degradation by recombinant human MMP-19 to 105-kDa and 80-kDa fragments. Parental HaCaT grown on the matrix of HaCaT-WT and HaCaT-EA cells displayed differential tyrosine phosphorylation. Using integrin blocking and stimulating antibodies we could attribute these differences to a shift from 4-integrin-dependent signaling on the HaCaT-EA matrix toward 3-integrin-dependent signaling on the HaCaT-WT matrix. As a consequence, parental HaCaT showed increased migration on the matrix of HaCaT-WT cells. These data suggest that the MMP-19-dependent processing of the 2 chains leads to the integrin switch favoring epithelial migration and that MMP-19 actively participates in the early stages of SCC invasion.Received 29 October 2004; received after revision 7 December 2004; accepted 17 January 2005     

The universality and biological significance of signal molecules with intracellular-extracellular compatible functions

Generally, cell signal molecules are classified into the extracellular signal molecules (the first messengers) and the intracellular signal ones (the second messengers). Cyclic adenosine monophosphate (CAMP), calcium ions and calmodulin (CaM) are the traditional intracellular messengers, but they are also present in extracellular matrix (ECM). Some of them have been discovered to act as the first messengers through cell surface receptors. Other second messengers, such as cyclic guanosine monophosphate (cGMP), cyclic adenosine diphosphate ribose (cADPR) and annexin, are also found existing outside animal and plant cells. The existence of these messengers with intracellular-extracellular compatible functions in cells may be a regular biological phenomenon. These compatible messengers might be the communication factors between intracellular and extracellular regions or among the cell populations, and are also important in regulating cell development procedure.