Experimental Study on Allogenic Decalcified Bone Matrix as Carrier for Bone Tissue Engineering

The biocompatibility and osteogenic activity of allogenic decalcified bone matrix (DBM) used as a carrier for bone tissue engineering were studied. Following the method described by Urist, allogenic DBM was made. In vitro, DBM and bone marrow stromal cell (BMSC) from rab-bits were co-cultured for 3-7 days and subjected to HE staining, and a series of histomorphological observations were performed under phase-contrast microscopy and scanning electron microscopy (SEM). In vivo the mixture of DBM/BMSC co-cultured for 3 days was planted into one side of muscules sacrospinalis of rabbits, and the DBM without BMSC was planted into other side as con-trol. Specimens were collected at postoperative week 1, 2 and 4, and subjected to HE staining, and observed under SEM. The results showed during culture in vitro, the BMSCs adherent to the wall of DBM grew, proliferated and had secretive activity. The in vivo experiment revealed that BMSCs and undifferentiated mesenchymal cells in the perivascular region invaded gradually and proliferated together in DBM/BMSC group, and colony-forming units of chondrocytes were found. Osteoblasts,trabecular bone and medullary cavity appeared. The inflammatory reaction around muscles almost disappeared at the second weeks. In pure DBM group, the similar changes appeared from the sur-face of the DBM to center, and the volume of total regenerate bones was less than the DBM/BMSC group at the same time. The results indicated that the mixture of DBM and BMSC had good bio-compatibility and ectopic induced osteogentic activty.     

Cell–matrix adhesion in vascular development

Summary.  Vascular development requires correct interactions among endothelial cells, pericytes and surrounding cells. These interactions involve many cell adhesion interactions, including cell–matrix interactions both with basement membranes and with surrounding extracellular matrices. Investigations of the contributions of these various interactions in vascular development and angiogenesis have been rather uneven and incomplete over the past 10–15 years. There has been considerable concentration on a few receptors, matrix proteins and proteolytic fragments with the goal of finding means to control angiogenesis. Many other potential contributors have received much less attention. Even for those molecules that have been subject to intensive investigation, our knowledge is incomplete. This review will survey the spectrum of extracellular matrix (ECM) proteins and cell–matrix adhesion receptors (particularly integrins) that are likely to contribute to angiogenesis and discuss what is known and not known about the roles of each of them.     

尿转化生长因子-β1和细胞外基质在慢性肾小球肾病中的变化

目的：探讨尿中转化生长因子-β1（TGF-β1）和细胞外基质（ECM）在各种慢性肾小球肾病患者中的变化及其临床意义。方法：将105例慢性肾小球患者进行临床和病理分组,采用酶联免疫吸附试验（ELISA）分别检测各组的尿TGF-β1水平,同时采用放射免疫分析法（RIA）检测尿中的各种ECM,所有检测值均用尿肌酐（Cr）浓度进行校正。结果：在不同临床分组中,尿TGF-β1/Cr和LN/Cr、PCⅢ/Cr、Ⅳ-C/Cr水平明显高于对照组（P〈0.05）,尿HA/Cr水平则在Ⅲ、Ⅳ组中出现下降。而在不同的病理分组中,肾小球轻微病变（GML）组尿中TGF-β1、ECM与对照组比较无统计学意义,其他各病理分组则出现不同的变化。相关性分析尿TGF-β1/Cr与LN/Cr、PCⅢ/Cr、Ⅳ-C/Cr正相关,与HA/Cr无相关性。结论：通过尿TGF-β1和ECM在慢性肾小球肾病患者中的联合检测,对评价慢性肾小球肾病的进展和预后判断提供一定的临床价值。     

改良消蚀法制备脱细胞真皮基质微粒及其生物相容性评价

目的:利用改良消蚀法制备一种新型脱细胞真皮基质(Acellular dermal matrix,ADM)微粒,并对其相容性加以评价,为组织工程微粒皮肤的制备奠定研究基础。方法:应用机械法切除猪真皮乳头层,结合消蚀法和冻融法除去网状真皮中的所有细胞制备成ADM,将ADM搅碎成颗粒状,对其做细胞毒性实验和皮下埋藏实验检验其相容性。结果:该方法制备的ADM微粒韧性好,细胞去除完全,胶原三维稍松散但结构完整,无基底膜和乳头层。细胞毒性实验显示其基本无毒性,成纤维细胞在ADM微粒上增殖良好,皮下埋藏试验未见明显排异反应,ADM微粒能诱导血管和成纤维细胞长入。结论:用改良消蚀法制备的ADM微粒抗原性低、相容性好,可以作为组织工程微粒皮肤的支架和填充材料。     

酸性成纤维细胞生长因子在宫颈癌中的表达及其信号传导途径

目的探讨酸性成纤维细胞生长因子(aFGF)在宫颈癌发生发展中的作用及其信号传导机制.方法应用逆转录-聚合酶链反应技术(RT-PCR)对36例宫颈癌组织aFGF 及其受体FGFR1的表达进行了分析;并以不同浓度的aFGF 和酪氨酸蛋白激酶(TPK)抑制剂genistein诱导宫颈癌细胞株HeLa细胞,[γ-32P]ATP掺入外源性底物的方法,液体闪烁测定蛋白激酶C(PKC)及细胞外信号调节激酶(ERK)的活性.结果 aFGF mRNA 和FGFR1 mRNA在宫颈癌组织中的半定量检测结果分别为(1.233±0.064)和(1.168±0.103),与正常宫颈组织相比,差异有显著性(P<0.05),且在Ⅲ～Ⅳ期宫颈癌中的表达水平明显高于Ⅰ～Ⅱ期(P<0.05);随着aFGF浓度的增加,HeLa细胞PKC及ERK 活性随之升高,与aFGF浓度呈剂量依赖效应;genistein抑制细胞内PKC及ERK 活性,与genistein 浓度亦呈剂量依赖效应.结论提示aFGF 与宫颈癌的发生、发展、浸润呈正相关,其受体具有TPK活性,TPK激活后可进一步激活PKC和ERK,进一步证明PKC及ERK确是TPK的下游信号分子.     

G蛋白耦联受体激酶结合蛋白1通过调节细胞外调节激酶1/2的活性促进成骨细胞迁移

目的探索G蛋白耦联受体激酶结合蛋白1(GITI)在成骨细胞迁移中的作用,并分析其机理。方法通过Western blot方法检测GIT1蛋白在鼠的成骨细胞内的表达；用免疫荧光染色方法确定：在血小板衍生生长因子(PDGF)不刺激和刺激的条件下,GIT1和细胞外调节激酶1/2(ERK1/2)在成骨细胞内的位置；用共同免疫沉淀的方法测定GIT1和ERK1/2相互结合,并且用免疫荧光双染的方法确定这两种蛋白相互结合的位置；用包含GIT1-RNA发夹结构的腺病毒感染成骨细胞后,用免疫荧光染色方法确定磷酸化ERK1/2(pERK1/2)在成骨细胞内的位置,用划痕愈合法检测在PDGF刺激下的迁移能力。结果在成骨细胞内,PDGF刺激导致了GIT1和ERK1/2的相互结合,并且这种结合发生在成骨细胞的局部粘附内。包含GIT1-RNA发夹结构的腺病毒明显抑制了pERK1/2招募至成骨细胞局部粘附内以及PDGF所刺激的成骨细胞的迁移。结论在PDGF刺激下,GIT1招募pERK1/2至成骨细胞的局部粘附内,从而促进成骨细胞的迁移。     

不同种属脱细胞真皮与自体皮复合移植的比较性研究

目的　观察不同种属脱细胞真皮基质 (acellulardermalmatrix,ADM)与自体皮复合移植的效果 ,为异种ADM的临床应用提供理论依据。　方法　本地产白色小猪 6头 ,分为异种 (人 )ADM +自体刃厚皮组 (A组 )、同种异体 (猪 )ADM +自体刃厚皮组 (B组 )、单纯自体刃厚皮组 (C组 )及单纯自体中厚皮组 (D组 )。观察术后 2、4、8、12、2 4周内移植物存活率 ,以及移植皮片收缩程度、移植区组织学变化等情况。　结果　A、B组移植后皮片外观光滑、有弹性 ;两组均获得了满意的皮片成活率 ,并可迅速诱导成纤维细胞、血管内皮细胞等宿主修复细胞的长入 ;两组移植皮片收缩面积有大于C、D组的趋势 (P <0.0 5);术后 2 4周移植区组织与单纯中厚皮移植组织结构一致。　结论　在观察期内(复合移植后 2 4周 ) ,与自体皮复合移植时 ,同、异种ADM具有相近的生物学作用 ,异种来源的ADM可能具有更广阔的应用前景     

大鼠良性前列腺增生组织中细胞外基质的免疫组化研究

为了研究性激素及细胞外基质在良性前列腺增生(BPH)发生中的相互作用,实验建立大鼠BPH模型,并采用免疫组织化学ABC法对大鼠前列腺组织中的纤维连续蛋白(FN),Ⅳ型胶原蛋白(COL IV)进行表达,发现睾丸素组的前列腺重量明显增加,FN及COL IV强阳性染色率显著高于去势组及对照组(P<0.01,0.05),而且前列腺的重量分别与FN,COL IV表达呈正相关(P<0.05)。提示在大鼠BPH模型中细胞外基质成分增加,增殖的细胞与大量积聚的细胞外基质共同作用导致BPH的发生。     

Role of the extracellular matrix in neural crest cell migration

Development of the neural crest involves a remarkable feat of coordinated cell migration in which cells detach from the neural tube, take varying routes of migration through the embryonic tissues and then differentiate at the end of their journey to participate in the formation of a number of organ systems. In general, neural crest cells appear to migrate without the guidance of long-range physical or chemical cues, but rather they respond to heterogeneity in the extracellular matrix that forms their migration substrate. Molecules such as fibronectin and laminin act as permissive substrate components, encouraging neural crest cell attachment and spreading, whereas chondroitin sulphate proteoglycans are nonpermissive for migration. A balance between permissive and nonpermissive substrate components seems to be necessary to ensure successful migration, as indicated by a number of studies in mouse mutant systems where nonpermissive molecules are over-expressed, leading to inhibition of neural crest migration. The neural crest expresses cell surface receptors that permit interaction with the extracellular matrix and may also modify the matrix by secretion of proteases. Thus the principles that govern the complex migration of neural crest cells are beginning to emerge.     

Distribution of extracellular matrix components and their receptors in human lymphoid tissue and B-cell non-Hodgkin lymphomas

In this study the distribution patterns of various extracellular matrix components and their receptors (i.e. β1 integrins) in B-cell non-Hodgkin lymphomas were examined and compared to those in reactive lymphoid tissue. Neoplastic follicles within follicular lymphomas showed similar patterns to that observed in reactive follicles, which appeared to be strongly associated with the presence of follicular dendritic cells. Diffuse lymphomas of low and intermediate malignancy grade revealed features comparable to those of interfollicular areas of reactive lymphoid tissue, irrespective to which compartment the tumour cells were related. Highly malignant lymphomas, however, displayed unique extracellular matrix configurations, resulting from active matrix degradation by macrophages; this may support rapid tumour growth. Extranodal lymphomas showed virtually the same matrix patterns as their nodal counterparts, suggesting that (malignant) lymphoid cells generate (at least partly) their own specific microenvironment. In reactive lymphoid tissue β1 integrins were mainly found on resident cells and except for α4, α5 (and β1) the lymphoid cells expressed very little, if any, β1 integrins. In comparison, expression of these integrins on lymphoma cells was reduced (follicular lymphomas) or could not be detected at all (diffusely growing lymphomas); this might contribute to the growth pattern and metastatic properties of the tumours.