(-)-Epigallocatechin-3-gallate,reduces corneal damage secondary from experimental grade II alkali burns in mice

Background

Since recent reports have shown that (-)-Epigallocatechin-3-gallate (EGCG) could be used for treating proliferative and inflammatory disorders, we explored its use for the management of corneal chemical burns.

MMP-2、TIMP-2与碱烧伤后角膜新生血管形成的实验研究

目的:探讨基质金属蛋白酶-2(MMP-2)、基质金属蛋白酶-2组织型抑制剂(TIMP-2)在碱烧伤大鼠角膜新生血管(CNV)形成中的表达和意义。方法:采用碱烧伤大鼠角膜建立CNV模型,摘除角膜作病理切片,多形核白细胞(PMN)记数;免疫组化法检测MMP-2、TIMP-2的表达。结果:烧伤后1d角膜缘PMN开始增多,到CNV7d组PMN增加最明显,此后逐渐减少;免疫组化显示:MMP-2在CNV中阳性表达逐渐增加,于7d表达最明显,此后随炎性细胞的减少而减弱,21d后几乎无表达;TIMP-2则于早期变化不明显,7d表达开始升高,14d达高峰。结论:烧伤后CNV形成早期,MMP-2活性增高,继而TIMP-2表达增加,使MMP-2活性受抑,基底膜降解受阻,新生血管延伸停滞;CNV形成中,MMP-2的表达增加,并与角膜的炎性反应程度一致,PMN浸润可能是CNV形成的关键因素。     

环缩酚肽抑制视网膜表达VEGF及PECAM基因和血管增生

[目的]观察两种环缩酚肽衍生物(Hep-A和Hep-B)对氧诱导的小鼠视网膜表达血管内皮生长因子(VEGF)和细胞黏附分子(PECAM;ICAM-1;VCAM-1)基因的影响及血管增生的变化.[方法]建立氧诱导的血管增殖性视网膜病变模型,12 d开始给小鼠皮下注安慰剂(第1组,n=7)、Hep-A 10 mg/kg(第2组,n=6)或者Hep-B 10 mg/kg(第3组,n=6),每天两次.5 d后取出左侧眼,分离视网膜并抽提RNA,用荧光定量PCR测出上述基因含量,并分别求出每个靶基因与标准基因S16含量的比率;右眼经心脏荧光素灌注后取眼球做视网膜平铺片,用图像分析软件定量计算视网膜新生血管的面积.[结果]视网膜中VEGF/S16的mRNA比率为:第1组(0.554±0.050),第2组(0.355±0.037),第3组(0.287±0.051);PECAM/S16为:第1组(2.050±0.249),第2组(1.228±0.153),第3组(1.027±0.210).经ANOVA分析,第2组和第3组分别与第1组比较,视网膜中VEGF基因表达分别减少36%和48.2%(P=0.001);PECAM基因表达分别减少40.1%(P＜0.05)和49.9%(P＜0.01);而VCAM-1和ICAM-1表达无明显差异.视网膜平片检测视网膜新生血管面积:第1组为(1.06±0.03)mm2/眼,第2组为(0.17±0.01)mm2/眼,第3组为(0.11±0.01)mm2/眼;经ANOVA分析,第2组和第3组分别与第1组比较,视网膜新生血管的面积明显减少(P＜0.001).[结论]两种环缩酚肽衍生物均抑制氧诱导的小鼠视网膜表达VEGF和PECAM基因,并抑制其形成视网膜新生血管.     

Inhibition of angiogenesis by antibody blocking the action of proangiogenic high-molecular-weight kininogen

Summary.  Previously we demonstrated that domain 5 (D5) of high-molecular-weight kininogen (HK) inhibits neovascularization in the chicken chorioallantoic membrane (CAM) assay and further found that kallikrein cleaved HK (HKa) inhibited FGF2-and VEGF-induced neovascularization, and thus was antiangiogenic. In this study, we sought to demonstrate whether uncleaved HK stimulates neovascularization and thus is proangiogenic. The chick chorioallantoic membrane was used as an in ovo assay of angiogenesis. Low-molecular-weight kininogen stimulates angiogenesis, indicating that D5 is not involved. Bradykinin stimulates neovascularization equally to HK and LK and is likely to be responsible for the effect of HK. A murine monoclonal antibody to HK (C11C1) also recognizes a similar component in chicken plasma as detected by surface plasmon resonance. Angiogenesis induced by FGF2 and VEGF is inhibited by this monoclonal antibody and is a more potent inhibitor of neovascularization induced by VEGF than an integrin α_vβ₃ antibody (LM 609). Our postulate that C11C1 inhibits the stimulation of angiogenesis by HK was confirmed when either C11C1 or D5 completely inhibited angiogenesis in the CAM induced by HK. Growth of human fibrosarcoma (HT-1080) on the CAM was inhibited by GST-D5 and C11C1. These results indicate HK is proangiogenic probably by releasing bradykinin and that a monoclonal antibody directed to HK could serve as an antiangiogenic agent with a potential for inhibiting tumor angiogenesis and other angiogenesis-mediated disorders.     

不同日龄新生小鼠视网膜血管对氧疗的敏感性

目的观察不同日龄新生小鼠对氧疗的敏感性,研究视网膜血管的发育程度与新生血管形成的关系。方法选择4、7、9、11日龄C57BL/6J新生小鼠各48只,分为高氧组和空气组,通过视网膜铺片(ADP酶染色)和视网膜切片(HE染色),定性和定量观察视网膜血管的增生情况。结果与各空气组相比,4、7、9日龄高氧组小鼠吸高氧5d,返回空气第5天时,大量新生血管形成。而11日龄高氧组小鼠在返回空气第5天未见新生血管形成。4、7、9、11日龄高氧组小鼠出氧箱第5天突破视网膜内界膜的血管内皮细胞核数目分别为25.0±3.7、47.7±5.0、18.7±2.0、2.6±1.4个,4、7、9、11日龄空气组分别为0.7±1.1、1.2±1.2、0.8±1.0、1.6±1.0个,4、7、9日龄高氧组细胞核数目明显增多,与相应的空气组比较,差异有显著性(P<0.001);11日龄高氧组细胞核数无明显增多,与11日龄空气组比较,差异无显著性。结论视网膜血管的发育程度与新生血管形成有关,视网膜血管发育越不成熟越易发生视网膜病变,而发育成熟的视网膜则不会发生视网膜病变。     

可溶性fms-样酪氨酸激酶受体-1不同基因片段对视网膜新生血管的抑制作用

Objective To investigate the inhibitory effects of fms-like typrosine kinase receptor sFh-1 on retinal neovascularization (RNV). Methods Recombinant lentivirus sFh-1 ( 2-3 ) and sFh-1 ( 2-4 )expressing the sFh-1 (2-3) and (2-4) immunoglobulin-like regions of sFh-1 were constructed. 96 seven-dayold C57/6J mice were randomly divided into 4 groups with 24 mice in each group. Group 1 : normal control;group 2: experimental control; group 3: sFlt-1(2-3); group 4: sFlt-1(2-4). The mice in group 2-4 were exposed to hyperoxia with (75±2)% O2 for 5 days and then returned to normoxia with 21% O2 ; the mice     

口腔鳞癌巨噬细胞和微血管的空间关系

目的 :研究鳞癌组织中肿瘤相关巨噬细胞 (TAMs)和肿瘤微血管在局部空间的相互关系。方法 :采用免疫组化双染的方法观察标记巨噬细胞和微血管。结果 :在口腔鳞癌中TAMs密集的区域与微血管密集区域 ,两者的TAMs和微血管记数呈现相反的关系 (P <0 0 0 1)。结论 :在口腔鳞癌中TAMs迁徙、聚集到缺氧的区域 ,参与肿瘤的血管生成 ,但具体机制仍需进一步研究     

Patterns of angiogenesis in neural transplant models: I. Autonomic tissue transplants

Functional vascular connections must form rapidly to prevent ischemic damage to grafted neural tissues. The temporal sequence by which transplant circulation is re-established provides information about the angiogenic capacity of either intact or damaged CNS blood vessels. This study compares the time course and mechanism of vascular reperfusion in allografts of superior cervical ganglia or adrenal medulla inserted either into the fourth ventricle or directly into the parietal cortex of perinatal rats. Tritiated thymidine was administered to recipients to determine angiogenic patterns at various postoperative time periods. After processing for light microscopic autoradiography, host and graft endothelial labelling indices were determined in order to establish the temporal sequence and location of vascular proliferation. Correlative electron microscopy depicted the morphological changes in transplant vasculature. Some recipients were prelabelled with 3H thymidine prior to transplantation to determine if host vessels invaded the grafts. Intraventricular graft vessels initially collapsed but sustained minimal ischemic damage and were completely reperfused by 24 hours postoperative. Adjacent intact host vessels attained peak 3H thymidine incorporation at 20 hours. Intrinsic graft vessels were radioactively labelled only after 48 hours. Intraparenchymal transplants surrounded by minimal trauma exhibited a similar temporal sequence of reperfusion and host endothelial proliferation. Intrinsic graft vessels in intraparenchymal grafts sustained more severe damage. With increased trauma, a concomitant delay in graft reperfusion time was observed. Grafts within prelabelled hosts rarely contained any labelled endothelium, indicating that anastomotic connections were made between original, intrinsic graft vessels and nearby host vascular sprouts. This study demonstrates that mature autonomic tissue stimulates the growth of adjacent host vessels when transplanted to undamaged brain surfaces. The anastomosis of nascent host vessels with pre-existing graft vessels is responsible for the rapid re-establishment of circulation within the transplants. A similar mechanism occurs within intraparenchymal grafts, although the rapidity of reperfusion appears to be predicated on the amount of trauma present at the graft site.     

Vasculogenic mimicry has no prognostic significance in pT3 and pT4 cutaneous melanoma

The concept of vasculogenic mimicry has been introduced to define periodic acid-Schiff (PAS)-positive channels and loops lined by tumor cells, instead of endothelium, able to contribute to microcirculation in uveal melanomas. Previous studies have shown that the PAS-positive patterns are associated with a poor prognosis in uveal melanoma. The aim of the current study was to investigate whether vasculogenic mimicry has a prognostic impact in pT3 and pT4 cutaneous melanoma. Fifteen patients with pT3 and pT4 cutaneous melanoma who did not experience progression after 10 years of follow-up and 30 matched controls who underwent progression were selected. Tumor sections were stained with PAS reaction, omitting the nuclear counterstaining. For immunohistochemistry, sections were stained with CD31, CD105 (endoglin), and laminin. Differences in the distribution of the PAS-positive patterns and a series of clinicopathological variables were evaluated by the Pearson chi(2) and Mann-Whitney U tests. We observed PAS-positive linear sheets, arcs, elliptical loops, and networks encircling roundish to oval aggregates of melanoma cells. The overall distribution of the PAS-positive patterns did not match with the blood microvessels' architecture as detected by immunohistochemical analysis. No statistically significant differences in the distribution of PAS-positive patterns were found between cases and controls. The presence of a parallel pattern correlated significantly with thickness (P = 0.04), whereas an inverse correlation was found with vessel area (P = 0.05). In conclusion, our results suggest that there is a mismatch between vasculogenic mimicry and tumor angiogenesis and do not support any prognostic role of vasculogenic mimicry in thick cutaneous melanoma.