Vascular endothelial growth factor and its receptor expression during the process of fracture healing

Objective： To study the expression regularity of vascular endothelial growth factor （VEGF） during the process of fracture healing, and the type of VEGF receptor expressed in the vascular endothelial cells of the fracture site.
Methods： The fracture model was made in the middle part of left radius in 35 rabbits. The specimens from the fracture site were harvested at 8, 24, 72 hours and 1, 3, 5, 8 weeks, and then fixed, decalcified, and sectioned frozenly to detect the expression of VEGF and its receptor at the fracture site by in situ hybridization and immunochemical assays.
Results： VEGF mRNA and VEGF expression was detected in many kinds of cells at the fracture site during 8 hours to 8 weeks after fracture. Fltl receptor of VEGF was found in the vascular endothelial cells at the fracture site during 8 hours to 8 weeks after fracture, and strong expression of flkl receptor was detected from 3 days to 3 weeks after fracture.
Conclusions： The expression of VEGF and fltl receptor appears during the whole course of fracture healing, especially from 1 to 3 weeks. Flkl receptor is highly expressed in a definite period after fracture. VEGF is proved to be involved in the vascular reconstruction and fracture healing.     

子宫内膜异位症患者血清及腹腔液中血小板衍生生长因子、血管细胞粘附分子水平的变化及其意义

目的通过检测子宫内膜异位症(EMs)患者血清及腹腔液中血小板衍生生长因子(PDGF)、血管细胞粘附分子-(VCAM-1)浓度,探讨PDGF和VCAM-1在EMs发病中的作用。方法选取手术后病理证实为EMs的40例患者为EMs组,其中I~II期17例,III~IV23例;非EMs组20例作为对照组。应用酶联免疫吸附法(ELISA)检测血清及腹腔液中PDGF和VCAM-1水平。结果EMs组血清及腹腔液中PDGF、VCAM-1水平均明显高于对照组(P<0.01)。随EMs期别的增加,其血清和腹腔液中PDGF、VCAM-1含量呈上升趋势;EMsIII~IV期水平显著高于I~II期(P<0.05)。EMs患者PDGF与VCAM-1呈正相关性(P<0.05)。结论EMs患者PDGF、VCAM-1表达水平升高,在EMs的发生发展中具有重要作用。     

重组人生长激素对荷人胃癌裸鼠移植瘤血管内皮生长因子表达的影响

目的研究重组人生长激素（rhGH）对生长激素受体（GHR）不同表达状态裸鼠人胃癌移植瘤生长及血管内皮生长因子（VEGF）表达的影响。方法采用免疫细胞化学染色法筛选出GHR阳性和阴性表达的细胞株各1株，分别接种于24只裸鼠皮下。将两种细胞接种裸鼠均随机分为对照组（0．9％NaCl，0．2ml／d）、低剂量rhGH组（0．5U·kg^-1·d^-1，0．2ml／d）和高剂量rhGH组（2．5U·kg^-1·d^-1，0．2mL／d）3组，每组8只，各组均连续给药14d，观察并记录裸鼠体重和肿瘤体积变化；采用酶联免疫吸附法测定各组裸鼠血清VEGF含量，免疫组织化学方法检测胃癌组织中VEGF蛋白表达，RT-PCR方法检测胃癌组织VEGFmRNA水平变化。结果筛选出GHR阳性表达的人胃癌细胞株SGC-7901和阴性表达的MKN-45。对于GHR^＋SGC-7901接种裸鼠，rhGH给药组皮下移植瘤体积较对照组增大（P〈0．05），且高剂量rhGH组促增长效应最为显著（P〈0．05），3组间体重差异无统计学意义（P〉0．05）；高剂量rhGH组的血清VEGF浓度为（252．94±15．32）ng／L，明显高于对照组的（49．94±5．73）ng／L和低剂量rhGH组的（167．60±9．54）ng／L（P〈0．05）；对照组VEGF表达为中度阳性，rhGH给药组呈强阳性；高剂量rhGH组肿瘤组织中VEGFmRNA相对表达量为0．6470±0．0447，明显高于对照组的0．3230±0．0258和低剂量rhGH组的0．4120±0．0351（P〈0．05）。对于GHR—MKN-45接种裸鼠，rhGH给药组体重明显大于对照组（P〈0．05）；肿瘤体积大小、血清VEGF水平、肿瘤组织VEGF蛋白及mRNA表达，3组间差异均无统计学意义（P〉0．05）。结论rhGH能促进GHR阳性表达的SGC-7901移植瘤生长，并促进VEGF表达增高；对于GHR阴性的MKN-45移植瘤，则没有表现出明显的促肿瘤生长及促VEGF表达效应。GHR存在可能是rhGH影响VEGF分泌的关键靶点。     

Expression and distribution of vascular endothelial growth factor protein in human brain tumors

Marked neovascularization is a hallmark of many neoplasms in the nervous system. Recent reports indicate that the endothelial mitogen vascular endothelial growth factor (VEGF) may play a critical role in the regulation of vascular endothelial proliferation in malignant gliomas. Using novel monoclonal antibodies to the VEGF polypeptide we have determined the expression and cellular distribution of VEGF protein in a representative series of 171 human central nervous system (CNS) tumors by immunohistochemistry and immunoblotting. In agreement with previous in situ hybridization data, 19 out of 20 glioblastomas (95%) showed immunoreactivity for VEGF, whereas both the percentage of immunoreactive tumors and the extent of immunoreactivity for VEGF were significantly lower in astrocytomas. Of the pilocytic astrocytomas (WHO grade I) 44% were immunoreactive for VEGF, but we observed several cases with pronounced vascular proliferates in the absence of VEGF. In ependymomas, meningiomas, hemangioblastomas, and primitive neuroectodermal tumors, there was no correlation between VEGF expression, vascular endothelial proliferation and the grade of malignancy. Oligodendrogliomas and the oligodendroglial component of mixed gliomas lacked immunoreactive VEGF, indicating that endothelial growth factors other than VEGF may regulate tumor angiogenesis in these neoplasms. Western blot analysis showed a predominant VEGF protein species of 23 kDa and confirmed the immunohistochemical data in all cases. Our findings demonstrate that VEGF is expressed in a wide spectrum of brain tumors in which it may induce neovascularization. However, other angiogenic factors also appear to contribute to the vascularization of CNS neoplasms. Received: 18 April 1996 / Revised, accepted: 20 August 1996     

Vascular Access for Therapeutic Plasma Exchange

Abstract: Adequate venous access is an essential component of therapeutic plasma exchange (TPEX). The simplest kind of venous access is venipuncture of antecubital veins, but this technique may be limited by venous size or scarring following the procedure, requiring the placement of a specialized vascular access device (VAD). VADs provide reliable central venous access and may remain in place for several weeks or months, depending on the VAD and the venous site chosen. Their use, however, is potentially limited by the risk of complications. We discuss indications for insertion, choice of catheter and access site, and complications of VAD placement for TPEX.     

Tumor cell-enhanced sensitivity of vascular endothelial cells to photodynamic therapy

Effective antitumor photodynamic therapy (PDT) may be related to damage of vasculature within the tumor. The purpose of this study was to determine if tumor cells secrete factors that stimulate proliferation of human umbilical vein endothelial cells (HUVEC) and result in enhanced sensitivity of HUVEC to aluminum-sulfonated phthalocyanine (AISPc)-PDT. Three human tumor cell lines—pharyngeal squamous carcinoma, colonic carcinoma, and mammary carcinoma—were used in this study. Co-culture of HUVEC and either squamous carcinoma or colonic carcinoma, but not mammary carcinoma, significantly increased HUVEC proliferation and AlSPc-PDT mediated cell damage. In addition, supernatant from squamous carcinoma and colonic carcinoma cultures also stimulated HUVEC proliferation and sensitivity to AISPc-PDT. Both supernatant and cell lysate from squamous carcinoma cells contained angiogenic factors consistent with basic and acidic fibroblast growth factors, as evidenced by Western blot analysis and BALB/c 3T3 fibroblast cell proliferation assays. Collectively, these results suggest that selected tumor cell lines produce angiogenic factors that induce HUVEC proliferation and subsequently enhance sensitivity to AISPc-PDT. © 1994 Wiley-Liss, Inc.     

人大肠癌细胞株（HT29）与人多器官血管内皮细胞粘附数目及形态学观察

为了模拟体内癌细胞与血管内皮粘附的过程，用人大肠癌细胞与人多器官血管内皮细胞共同培养，观察到与不同血管内皮粘附的癌细胞数有显著性统计学差异（Ｐ＜０．０５—０．０１）。与门静脉、肠系膜静脉内皮粘附的癌细胞数多，细胞表面微绒毛多，丝状突起细长，伪足多且长；与大隐静脉内皮粘附的癌细胞数少，细胞表面突起也细小。这表明不同的血管内皮对癌细胞的粘附是具有选择性的。     

Time-resolved MR imaging by automatic data segmentation

A method for time-resolved imaging that provides a flexible trade-off between imaging time and temporal resolution is presented. It is based on a view order selection technique that automatically segments the acquired raw data into appropriate temporal frames. When used with cardiac monitoring and phase-contrast imaging, data similar to that obtained with a conventional gated phase-contrast sequence are acquired rapidly. For many applications, the temporal resolution can be reduced enough to permit imaging within a breath-hold interval, while still allowing accurate time-averaged flow quantitation. This is a general technique that can be implemented within a variety of pulse sequences and can resolve other motion cycles, including the respiratory cycle.     

Characterization of anti-endothelial cell antibodies in systemic lupus erythematosus (SLE).

IgG anti-endothelial antibodies (AEA), as measured by ELISA or immunoblotting technique could be detected in serum samples of 56 out of 64 patients with SLE (88%) and mainly occurred in monomeric form. AEA were not cell specific, because the binding reactivity was absorbed partially by both fibroblasts and peripheral blood mononuclear cells. No correlation was found between the presence of AEA and anti-nuclear antibodies. Immunoblotting revealed reactivity of AEA against endothelial antigens ranging in size from 15 to 200 kD. AEA titres were significantly higher in patients with joint or skin abnormalities, compared with patients without these abnormalities. A significant correlation was found between nephritis in SLE and the presence of AEA reactivity against endothelial membrane antigens of 38, 41 and 150 kD. These data show that the pattern of AEA reactivity in serum of SLE patients is heterogeneous, and suggest that AEA against a limited number of antigens may be involved in the pathogenesis of nephritis in SLE.     

An Appraisal of Different Cardiac Risk Reduction Strategies in Vascular Surgery Patients

OBJECTIVES: to summarize existing evidence regarding the benefits and the risks of all available interventional and medical means aimed at cardiac risk reduction in patients undergoing vascular surgery. DESIGN: review of the literature. MATERIALS AND METHODS: a critical review of all studies examining the impact of various prophylactic cardiac maneuvers on perioperative outcome following vascular surgery was performed. Overall mortality, cardiac mortality and myocardial infarction rate were used as the outcome measures. RESULTS: coronary artery bypass grafting is associated with a 60% decrease in perioperative mortality in patients undergoing vascular surgery, but in most of the cases this decrease does not outweigh the combined risk of the cardiac and the subsequent noncardiac vascular procedure. Data supporting the cardioprotective effect of percutaneous transluminal angioplasty in the perioperative setting are insufficient. beta-blockade has been shown to decrease perioperative mortality and cardiac morbidity in both high-risk (strong evidence) and low-risk (weak evidence) patients. CONCLUSIONS: coronary revascularization is rarely indicated to simply get the patient through vascular surgery and should be reserved for patients who would need it irrespective of the scheduled vascular procedure. Among all available pharmacological agents, including beta-blockers, alpha-agonists, calcium channel blockers and nitrates, only beta-blockers have been proven to reduce the cardiac risk of vascular surgery.