血管化对聚酯/钙磷盐支架修复兔桡骨缺损及支架降解的影响

目的:探索应用生长因子促进骨移植材料血管化的方法,检验血管化对新骨形成及移植物降解等方面的影响。方法:分别采用复合bBM P+bFGF及单纯复合bBM P的聚酯/钙磷盐载体材料(PLGA/TCP)修复兔桡骨15mm缺损,通过量化评价、影像学、组织学、材料降解及骨密度评价血管化对聚酯/钙磷盐载体材料修复兔桡骨缺损效果的影响。结果:术后12W时各组骨缺损均有不同程度的愈合,但复合bBM P+bFGF组与单纯复合bBM P组相比较,各检测指标均有显著性差异,加入血管化因素bFGF可明显提高骨缺损部位的血管化程度,加快骨缺损修复速度及材料降解速度。结论:加入bFGF作为血管化影响因素后,用PLGA/TCP材料修复兔桡骨缺损,骨缺损处的血管化程度有一定程度的提高,并相应的加速了骨修复速度及材料降解速度。     

冠状动脉粥样硬化斑块内血管新生与斑块稳定的关系

目的　比较稳定斑块和不稳定斑块内新生血管形态学分布和数量上的差异 ,探讨新生血管与斑块稳定的关系。方法　从死亡前有急性冠脉综合征发生的 5 2例尸检冠状动脉标本中选取晚期动脉粥样硬化病变的组织块共 92 2块 ,以脂质核心面积是否大于斑块面积的 4 0 %为标准将其分为不稳定斑块组 (15 3块 )和稳定斑块组 (76 9块 ) ,比较两组斑块内新生血管的检出率。由两组随机选取各 4 0个组织块进行第八因子相关抗原抗体的免疫组织化学染色 ,观察阳性物质在斑块内的分布特点并通过计算机图像分析系统进行量化分析。结果　不稳定斑块组新生血管检出率 (80 4 % )显著高于稳定斑块组 (6 6 6 % ,P <0 0 1)。新生血管主要分布在斑块的肩部和基底部 ,纤维帽相对较少 ;不稳定斑块组各部位的新生血管最大密度 [肩部 :(2 2 16± 19 96 )个 /mm2 ,基底部 :(2 1 6 8± 2 0 4 4 )个 /mm2 ,纤维帽 :(3 80± 5 32 )个 /mm2 ]均显著大于稳定斑块组的相应部位 [肩部 :(10 0 4± 11 5 2 )个 /mm2 ;基底部 :(9 6 8± 11 5 2 )个 /mm2 ;纤维帽 :(1 4 8± 2 2 8)个 /mm2 ,P <0 0 5 ]。结论　不稳定斑块组较稳定斑块组新生血管检出率和密度均显著增高 ,提示新生血管与斑块的不稳定性密切相关。除目前较为公认的脂质核心大小     

A study of neovascularization in the rat ischemic hindlimb using Araldite casting and Spalteholtz tissue clearing

INTRODUCTION: Understanding neovascularization is an important prerequisite for therapeutic advances aimed at the salvation of ischemic tissues. We explored an alternative strategy to corrosion casting for visualizing neovascularization in a rat hindlimb ischemia model. METHODS: Rats were subjected to hindlimb ischemia by femoral artery ligation. Directly after femoral artery occlusion and at 7, 14, 21 and 28 days postsurgery, rats were sacrificed, and neovascularization was evaluated by vascular casting with Araldite plastic and subsequent Spalteholtz tissue clearing. RESULTS: Semitransparent preparations were obtained, in which the casted arteries could be directly and three-dimensionally visualized in detail and in relation to the surrounding tissue. In the vascular casts, collateral formation and recanalization of previously thrombosed arteries were demonstrated. CONCLUSIONS: We describe an alternative approach to study neovascularization in animal models. This method, which combines Araldite plastic vascular casting with Spalteholtz tissue clearing, preserves all vasculature as well as the surrounding tissue. In a small time series in rat ischemic hindlimbs, we show that restoration of blood flow after ischemia not only involves newly formed collaterals, but also recanalization of previously thrombosed arterial segments.     

血管内皮祖细胞与缺血性心血管病的血管新生

1997年Ｔａｋａｙｕｋｉ等[1] 在Ｓｃｉｅｎｃｅ杂志发表论文报道血管内皮祖细胞 (ｅｎｄｏｔｈｅｌｉａｌｐｒｏｇｅｎｉｔｏｒｃｅｌｌｓ ,ＥＰＣ)分离成功 ,并可用于体内血管新生 (ａｎｇｉｏｇｅｎｅｓｉｓ)。当时提出的血管内皮祖细胞认为是假定的 (ｐｕｔａｔｉｖｅ)。但是 ,近年来随着干细胞研究的深入 ,血管内皮祖细胞的存在基本已经确认 ,而且它与血管新生间的关系日益受到重视[2 ,3 ] 。本文将讨论血管内皮祖细胞的特征 ,它与缺血性心血管疾病中血管新生的关系及其可能的应用前景。1　血管内皮祖细胞的特征　　血管内皮祖细胞是血…     

AN IMMUNOHISTOCHEMICAL STUDY OF NEOVASCULATURE IN HUMAN BRAIN TUMORS

In order to elucidate the characteristics of newly-formed small blood vessels in brain tumors, 51 cases of various types of brain tumor were studied immuno-histochemically. Endothelial cells in all tumor types reacted positively with anti-Factor VIH-related antigen (F-VIII Ag) and UEA-1. Reactivity to UEA-1 was limited to endothelial cytoplasm. Proliferating immature endothelial cells showed weak reactivity to anti-F-VIII Ag. In some cases of benign tumors diffuse reactivity to anti-F-VIII Ag was noted throughout thickened medial areas of the vascular walls, in which reactivity to anti-fibrous collagen and anti-flbronectin was noted. UEA-1 was thought to be a more specific endothelial marker than F-VIII Ag, especially for proliferating and Immature endothelial cells. It is strongly suspected that fibrous collagens are related to the formation of a thickened vascular wall in newly-formed small tumor vessels.     

Progranulin (granulin-epithelin precursor,PC-cell-derived growth factor,acrogranin) mediates tissue repair and tumorigenesis

Progranulin (Pgrn) is a pluripotent secreted growth factor that mediates cell cycle progression and cell motility. It activates the extracellular regulated kinases and phosphatidyl inositol-3 kinase signal cascades, among others, and increases expression of cyclins D and B. Structurally, it belongs to none of the well-established growth factor families. It regulates developmental events as diverse as the onset of cavitation in the preimplantation embryo and male-specific brain differentiation. During wound repair it promotes granulation and neovascularization. It regulates inflammation through a tripartite loop with secretory leukocyte protease inhibitor (SLPI) which protects pgrn from proteolysis, and elastase, which digests it to smaller peptides. Intact pgrn is anti-inflammatory through the inhibition of some of the actions of tumor necrosis factor, while the proteolytic peptides may stimulate the production of proinflammatory cytokines such as interleukin 8. Pgrn is highly expressed in aggressive cancer cell lines and clinical specimens including breast, ovarian, and renal cancers as well as gliomas. In experimental systems it confers an aggressive phenotype on poorly tumorigenic epithelial cancer cells. The malignancy of highly tumorigenic progranulin-expressing cell lines depends on the expression level of the pgrn gene since attenuating pgrn mRNA levels in pgrn-responsive cells greatly inhibits tumor progression. Given its actions in wound repair and tumorigenesis pgrn may prove a useful clinical target, both for prognosis and for therapy.Abbreviations EGF Epidermal growth factor - FAK Focal adhesion kinase - FGF Fibroblast growth factor - grn/epi Granulin-epithelin - IGF Insulin-like growth factor - MAPK Mitogen-activated protein kinase - MEF Mouse embryo fibroblast - PDGF Platelet-derived growth factor - Pgrn Progranulin - PI-3K Phosphatidylinositol-3 kinase - SLPI Secretory leukocyte protease inhibitor - TGF- Transforming growth factor- - TGFe Epithelial transforming growth factor - TNF Tumor necrosis factor - VEGF Vascular endothelial growth factor     

电磁场与组织工程组织血管形成

组织工程的血管化问题是制约组织工程产品的关键问题之一.为了解决这一问题,一些研究者使用电磁技术作用于内皮细胞或动物体观察血管形成情况.就电磁场对组织工程组织血管形成的影响作一综述.     

Parietal centripetal and centrifugal thickening neovascularization in the descending anterior coronary artery

Summary Left coronary arteries of 30 human hearts, obtained at autopsy, were injected with contrast medium. A control group was formed from anterior descending coronary arteries free of atherosclerosis and a study group from anterior descending coronary arteries with areas of atherosclerotic injury. The following differences in the two groups were noted. The control group did not show successfully injected vessels in intima and media, while cases with atherosclerotic injury have them; the number of injected vessels in presence of atherosclerotic injury was three times greater than in healthy coronary arteries; there was a decreasing gradient from outside to in, in the number of injected vessels in both groups; and finally in atherosclerotic vessels we noted a lack of balance between parietal thickening and the residual lumen (conspicuous thickening was accompanied by a small reduction in the lumen). We interpret centrifugal thickening as a possible compensatory mechanism in the major branches for an inadequate canalization of vessel, and suggest possible formation of coronary collateral circulation from vasa vasorum by a process of neovascularization.     

骨髓源性血管内皮前体细胞与出生后生理性和病理性血管形成

Endothelial progenitor cells （EPCs） exist in bone marrow, umbilical cord blood and peripheral blood of adult mammals, including humans. Furthermore, the discovery of EPCs has led to the notion of adult vasculogenesis, in which bone marrow (BM)-derived EPCs home to and incorporate into sites of new blood vessel formation, where they differentiate into endothelial cells, which is consistent with postnatal vasculogenesis. It has become apparent that circulating BM-derived EPCs are involved in promoting physiologic andpathologic neovascularization, such as wound healing and tumor growth. They are of great clinical importance in pro-or anti-angiogenic therapies.     

口服大剂量MPA对子宫内膜癌血管生成的影响

目的:探讨口服大剂量醋酸甲羟孕酮(MPA)对子宫内膜癌间质血管生成的影响。方法:选择经诊断性刮宫证实、未经任何治疗的子宫内膜癌20例,术前口服MPA55mg/d,连续10d。用免疫组化法(LSAB法)以CD34标记血管内皮细胞计数微血管密度(MVD),同时测定用药前后内膜癌标本中PR、VEGF、bFGF的表达,VEGF和bFGF采用计算机图象分析进行半定量分析,比较其用药前后在内膜癌中表达的变化。结果:用药后内膜癌中PR、bFGF的表达及MVD均明显低于用药前,差异有显著性(P<0.05),而用药前后VEGF的表达差异无显著性(P=0.09)。用药前后的内膜癌标本中VEGF和bFGF的表达均与MVD呈正相关(P<0.05)。结论:口服MPA能显著抑制内膜癌间质中的血管生成,其作用可能是通过调节bFGF而不是VEGF的表达实现的。