Vascular conditioning of the stomach before esophageal reconstruction by gastric interposition

Gastric interposition with intrathoracic or cervical esophagogastrostomy is currently the preferred operation for reconstruction after esophagectomy. Anastomotic leaks however result from poor vascular supply to the proximal stomach. They are responsible for significant morbidity and mortality. ‘Ischemic conditioning’ of the interposed stomach has been proposed as a technique where the ‘delay phenomenon’ aims at improving the microcirculation of the gastric conduit and preventing anastomotic leakage. Experimental observations and clinical studies have been conducted to document the immediate effects and results of this approach. The aim of this work is to review the principles, pathophysiology, experimental, and clinical evidence related to vascular conditioning of the stomach prior to esophagectomy with gastric interposition and esophagogastric anastomosis. MEDLINE and PubMed were searched to identify articles related to vascular conditioning of the stomach. Cross references were added and reviewed to complete the reference list. The anatomic basis of ischemic conditioning, the prevalence of ischemic events on the gastric conduit, the methodology to assess the microcirculation before and after gastric devascularization, animal experiments, and clinical studies reported on this approach were reviewed. Ten experimental works, eleven clinical observations, four reviews, and two editorial commentaries addressing ischemic conditioning of the stomach were identified and reviewed. Experimental observations document improved microcirculation to the proximal stomach following partial gastric devascularization. Clinical reports show the feasibility and relative safety of gastric ischemic conditioning. Preliminary observations suggest potential improvements to the gastric microcirculation resulting from gastric ischemic conditioning. This approach may help prevent complications at the esophagogastric anastomosis. The actual level of evidence however cannot promote its use outside of clinical research protocols.     

Correlation between serum levels of interleukin-6 and vascular endothelial growth factor in gastric carcinoma

BACKGROUND AND AIM: Vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) are associated with the disease status of gastric carcinoma. However, their relationship remains unclear. This study aims to determine and correlate serum levels of VEGF and IL-6 in gastric carcinoma. METHODS: A total of 107 patients receiving gastrectomy entered this study. Serum levels of VEGF and IL-6 were measured by using ELISA, and were analyzed by using the Student's t-test to compare means and by Pearson correlation analysis to calculate correlation coefficients with respect to pathological characteristics including depth of tumor invasion, Laurén's classification, tumor location, Borrmann classification, and the status of lymph node metastasis. RESULTS: Serum VEGF levels were significantly higher in patients with mixed type carcinoma (387.5 +/- 176.9 vs 255.3 +/- 154.1 pg/mL, P = 0.047) or lymph node metastasis (339.1 +/- 205.1 vs 223.2 +/- 197.4 pg/mL, P = 0.007). Serum IL-6 levels were significantly higher in patients with Borrmann type IV carcinoma, compared with Borrmann type II and III carcinoma. In general, no correlation was noted between serum VEGF levels and IL-6 levels (r = 0.142, P = 0.145), but significant correlation was found in patients with early gastric carcinoma (r = 0.627, P = 0.004) or mixed type carcinoma (r = 0.804, P = 0.016). CONCLUSIONS: This study supports the correlation between serum VEGF and IL-6 levels in distinct subsets of gastric carcinoma patients, and indicates that IL-6 may play a role for the angiogenesis of gastric carcinoma via modulation of VEGF.     

LKB1和血管内皮生长因子在胃癌组织中的表达及其临床意义

目的探讨LKB1和血管内皮生长因子(VEGF)在胃癌中的表达及临床意义。方法采用免疫组织化学(SP)法检测115例胃癌组织和20例胃正常组织中LKB1和VEGF的表达,并探讨其与胃癌分期、淋巴结转移、Lauren's分型及预后的关系。结果 LKB1在胃癌组织中的阳性率为20.9%,低于正常胃组织中的95.0%(P0.01);VEGF在胃癌组织中的阳性率为64.3%,高于正常胃组织中的5.0%(P0.01)。LKB1在胃癌组织中的低表达与胃癌的TNM分期、淋巴结转移、Lauren's分型及预后有关(P0.05);VEGF在胃癌中的表达与淋巴结转移、远处转移、TNM分期及预后相关(P0.05)。结论 LKB1的低表达与胃癌的发生、发展有关,对胃癌恶性生物学行为的评估及预后判断具有重要的指导意义。     

Serum levels of the angiogenic cytokines basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) in multiple myeloma

Angiogenesis is a crucial process in growth and progression of cancer and there is growing evidence that neovascularisation is important in hematological malignancies. Since an increased angiogenic potential has been identified in multiple myeloma, we simultaneously measured circulating serum levels of the cytokines bFGF, VEGF, HGF and IL-6 by ELISA in 67 patients with multiple myeloma or monoclonal gammopathies of undetermined significance (MGUS) and in 20 controls. Median values of bFGF were 4.7 pg/ml in healthy volunteers, 6.2 in MGUS, 6.3 in myeloma stage I, 13.4 in stage II and 21.7 in stage III. Myeloma patients had significantly higher bFGF serum levels than controls (p<0.001). Pretreatment bFGF levels differed significantly in the Salmon and Durie stages I-III (p=0.02) and were significantly elevated in stage II-III compared to stage I myeloma (p=0.02). In patients responding to chemotherapy according to the CLMTF criteria, a significant decrease in serum bFGF, VEGF and HGF levels occurred (median pretreatment values for bFGF 23.9 pg/ml, post-treatment 6.5 pg/ml; p<0.001, for VEGF 223 pg/ml versus 105 pg/ml; p=0.02 and for HGF 1429 pg/ml versus 1077 pg/ml; p=0.02, respectively). In 11 patients who did not achieve a remission, there was no significant decrease in bFGF, VEGF and HGF levels. These data show that myeloma in stages II and III is associated with an increase in serum bFGF concentrations and give the first report that effective chemo-therapy is accompanied by a significant decrease in the angiogenic factors bFGF, VEGF and HGF, while no decrease of these factors could be found in nonresponders.     

Vascular endothelial growth factor and microvascular permeability.

Vascular Endothelial Growth Factors (VEGFs) are endogenously produced vascular cytokines which result in angiogenesis, vasodilatation, and increased microvascular permeability in vivo. They are endothelial specific and result in mitosis, migration, stress fiber formation and increased permeability of endothelial cells in culture. They have been critically implicated in a host of pathological conditions including solid tumor growth and diabetes, and been proposed as a therapy for coronary and peripheral ischemic disease. However, the potent permeability-enhancing properties of VEGFs are very poorly understood. The pharmacology, signal transduction pathways, intracellular signaling mechanisms, and ultrastructural changes which result in increased permeability are still not clear. This review discusses the available evidence for how VEGFs increase permeability in vivo, and some of the pitfalls in interpreting experiments which do not take into account the vasoactive properties of VEGFs. It also discusses the clinical implications of the permeability enhancing effect of VEGFs, and the relevance of these studies to development of new therapies.     

Overexpression of c-H-ras p21 is correlated with vascular endothelial growth factor expression and neovascularization in advanced gastric carcinoma

BACKGROUND AND AIMS: ras Gene and its product (p21) have been reported to be associated with vascular endothelial growth factor (VEGF), which is one of the most important angiogenic factors, and tumor-associated angiogenesis. We tried to evaluate the correlation between the expression of c-H-ras gene product p21 and angiogenesis in advanced gastric carcinoma. METHODS: Immunohistochemical expression of c-H-ras p21 and VEGF was examined in 49 advanced gastric adenocarcinomas. In addition, double immunohistochemical staining was performed using anti-CD34 and anti-Ki-67 antibodies, and the intratumoral microvessel densities and their endothelial proliferative labeling indices were then counted to evaluate the degree of angiogenesis. RESULTS: The expression of c-H-ras p21 was demonstrated in 43 out of 49 gastric adenocarcinomas (87.8%). It did not correlate with histologic type, depth of invasion or metastasis. However, the degree of c-H-ras p21 expression was correlated with VEGF. In addition, the degree of c-H-ras p21 expression was correlated with increased intratumoral microvascular density and endothelial proliferative activity. CONCLUSIONS: We suggest that c-H-ras oncogene product p21 contributes to the upregulation of tumor-associated angiogenesis by the increased production of VEGF in advanced gastric carcinomas. Therefore, treatment involving the targeting of ras oncogene could inhibit solid tumor growth by suppressing tumor-associated angiogenesis.     

血管内皮生长因子与脑梗死

血管内皮生长因子(vascular endothelial growth factor,VEGF)是血管内皮细胞的一种特异性促分裂原,是最重要的促血管新生因子.VEGF在脑梗死后高度表达,在血管新生和神经保护中起着重要作用;同时,其过度表达也会使血管通透性增加,进而可能加重脑水肿.文章对VEGF及其受体与脑梗死的研究进展进行了综述.     

血管内皮生长因子在肺癌组织中表达的研究

目的　观察血管内皮生长因子 (VEGF)表达、肺癌组织微血管密度 (MVD)和肺癌临床病理指标及预后的关系 ,探讨VEGF的作用机制。　方法　应用免疫组化方法检测 6 0例肺癌患者肺癌组织标本MVD及VEGF的表达。　结果　①VEGF在肿瘤细胞、肺癌组织内巨噬细胞呈阳性 ,部分血管内皮细胞及成纤维细胞也呈弱阳性。②肺癌组织MVD计数在肺癌各项临床病理指标中无显著性差异 ,P >0 0 5 ;VEGF表达在不同N分期 (淋巴结转移 )及临床分期之间存在显著性差异 ( P <0 0 1,P <0 0 5 ) ,并随淋巴结转移及临床分期的进展而有逐渐增强的趋势。③血管高密度组VEGF表达阳性率为 77 4 %,明显高于血管低密度组 ( 44 8%) ,P <0 0 1。④CoxRegression风险比例模型分析 ,肺癌临床分期及VEGF表达可作为判断肺癌患者预后的独立指标。　结论　①VEGF可由肿瘤细胞、巨噬细胞及部分血管内皮细胞及成纤维细胞等多种细胞产生 ,通过旁分泌作用促进肿瘤血管生成。②VEGF在肺癌淋巴结转移及临床分期中起重要作用 ,并可作为判断肺癌患者预后的参考指标之一。     

Decreased salivary vascular endothelial growth factor in elderly patients with pneumonia during the course of recovery

Background: Elderly individuals are known for their high risk of acquiring pneumonia. Poor oral hygiene and high incidence of gastro‐oesophageal reflux continue to cause persistent oropharyngeal mucosal injuries and results in overgrowth of bacterial population and alteration of bacterial flora to respiratory pathogens in the oropharyngeal cavity. Salivary secretion contributes in maintaining homeostasis of the oropharyngeal mucosal barrier. Vascular endothelial growth factor (VEGF) acts as an angiogenic and permeability‐enhancing cytokine but is normally secreted in saliva. It has been previously demonstrated that VEGF secreted in the airway functions in the restoration or repair of the injured tissue. We hypothesized that salivary VEGF is a candidate as a marker to evaluate the degree of oropharyngeal mucosal injury. Methods: We compared the volumes, protein contents, and the amount of VEGF secreted in the saliva of patients with pneumonia during the course of recovery (P; n = 7) and those without pneumonia (n = 10). Results: Volumes and protein contents within the secreted saliva were similar between the patients with P and the control subjects (0.60 ± 0.28 mL versus 0.41 ± 0.34 mL, P = 0.126, 7.12 ± 5.57 µg/mL versus 3.92 ± 3.58 µg/mL, P = 0.231, respectively). The concentrations of salivary VEGF were significantly lower in patients with P than those of the controls (0.71 ± 0.37 versus 2.66 ± 3.44 µg/µg protein, P = 0.032). Conclusion: Lower concentrations of salivary VEGF in patients with pneumonia during the course of recovery suggested the presence of persistent oropharyngeal mucosal injury even after normalization of systemic C‐reactive protein levels. The concentration of salivary VEGF is capable of being a marker for discriminating impaired oral mucosal barrier that precipitates in development of pneumonia in elderly individuals.     

Bone marrow expression of vascular endothelial growth factor in myelofibrosis with myeloid metaplasia

The biologic relevance and prognostic impact of angiogenesis is being increasingly recognized in many solid tumors and hematologic malignancies including myelofibrosis with myeloid metaplasia (MMM). Many cytokines including vascular endothelial growth factor (VEGF) have been implicated for neoangiogenesis in MMM. However, the exact humoral basis remains to be elucidated. We examined the expression of VEGF by immunohistochemistry in a prospective cohort of 66 MMM patients, including six with cellular phase disease, and five normal controls. Contrary to most other hematologic malignancies, the distribution and intensity of staining for VEGF in bone marrow was similar between the MMM patients and controls. Interestingly, all six cellular phase patients displayed significantly increased VEGF expression. Thus, upregulation of angiogenic cytokines other than VEGF such as TGF-beta or loss of activity of an anti-angiogenic cytokine might be the dominant pathway of endothelial activation in MMM. However, VEGF might contribute to the process in the early stages of the disease.     

Vascular endothelial growth factor protects hepatoma cells against oxidative stress-induced cell death

BACKGROUND: The aim of the present study was to examine coordination of the vascular endothelial growth factor (VEGF) and VEGF receptor (Flk-1) system and to study control of VEGF expression by oxidative stress, which is considered a model for chronic liver disease. METHODS: Cell viability was determined by test method with 3-[4, 5-dimethylthiazol-2-yl]-2, 5-dephenyl tetrazolium bromide (MTT). Expressions of cellular proteins were evaluated by western blot analysis. RESULTS: The c-Met tyrosine phosphorylation in PLC/PRF/5 hepatoma cells was increased by treatment with 20 ng/mL hepatocyte growth factor (HGF), and extracellular signal-regulated kinase (ERK) was also activated. Although Flk-1 was phosphorylated in response to VEGF (>50 ng/mL), phosphorylated ERK was not detected at these concentrations. A total of 5.0 and 10 micromol/L hydrogen peroxide (H(2)O(2)) caused cell death in a dose-dependent manner after 24 h. On western blot analysis at 1 h with H(2)O(2), rapid phosphorylation of both ERK1/2 and c-Jun NH(2)-terminal kinase (JNK) was observed. In the first 6 h, H(2)O(2) induced cell death for 58.4 +/- 6.8%, whereas the presence of 100 ng/mL VEGF improved the survival rate to 77.2 +/- 4.2%. The VEGF significantly decreased H(2)O(2)-induced cell death after 12 h, whereas HGF (20 ng/mL) did not have a similar effect. When cells were incubated with 5 micromol/L H(2)O(2), expression of VEGF protein was detected. Furthermore, H(2)O(2)-induced phosphorylation of ERK and JNK was also reduced by VEGF (100 ng/mL). In contrast, HGF did not induce phosphorylation of ERK and JNK. CONCLUSION: Hepatoma cells might be able to survive under continuous oxidative stress through expression of VEGF.     

Vascular endothelial growth factor and diabetic retinopathy: pathophysiological mechanisms and treatment perspectives

Retinal neovascularization and macular edema are central features of diabetic retinopathy, the major cause of blindness in the developed world. Current treatments are limited in their efficacy and are associated with significant adverse effects. Characterization of the molecular and cellular processes involved in vascular growth and permeability has led to the recognition that the angiogenic growth factor and vascular permeability factor vascular endothelial growth factor (VEGF) plays a pivotal role in the retinal microvascular complications of diabetes. Therefore, VEGF represents an exciting target for therapeutic intervention in diabetic retinopathy. This review highlights the current understanding of the mechanisms that regulate VEGF gene expression and mediate its biological effects and how these processes may become altered during diabetes. The cellular and molecular alterations that characterize experimental models of diabetes are considered in relation to the influence of high glucose-mediated oxidative stress on VEGF expression and on the mechanisms of VEGF's actions under hyperglycemic induction. Finally, potential therapeutic strategies for preventing VEGF overexpression or blocking its pathological effects in the diabetic retina are considered.     

血管内皮生长因子对腹水性质的诊断价值

目的　探讨腹水中血管内皮生长因子 (VEGF)测定在良恶性腹水鉴别诊断中的价值 ,以及联合检测癌胚抗原 (CEA)的临床意义。方法　于 2 0 0 2 - 0 5～ 2 0 0 3- 0 2采用酶联免疫吸附法检测苏州大学附属第一医院住院患者 5 8例腹水中的VEGF、CEA质量浓度。结果　恶性腹水VEGF含量明显高于良性腹水 ,差异有显著性 (P <0 0 1)。联合测定腹水VEGF和CEA质量浓度 ,其诊断恶性腹水的敏感性较单独腹水CEA检测有明显提高 ,差异有显著性 (P <0 0 5 )。结论　腹水VEGF测定有助于良恶性腹水的鉴别诊断 ,联合检测腹水VEGF和CEA对于腹水的鉴别诊断更有临床实用价值。     

大肠癌组织中P16蛋白和血管内皮生长因子的表达及其临床意义

目的：探讨大肠癌组织中P16蛋白和血管内皮生长因子（VEGF）表达及其临床意认。方法：用S－P免疫组织化学方法测定66例大肠癌组织和20例正常大肠组织中P16蛋白和VEGF的表达。结果：大肠癌中P16蛋白阳性率为48．5％（32／66）明显低于对照组的70．0％（14／20）（P＜0．01），VEGF阳性率为72．7％（48／66）则明显高于对照组的15．0％（3／20）（P＜0．01）：P16蛋白和VEGF在大肠癌中表达具有明显负相关性；P16蛋白和VEGF表达与大肠癌组织学类型、肿瘤直径、肿瘤部位无关（P＞0．05），而与淋巴结转移、Duke's分期五年生存率有明显的关系（P＜0．01）。结论：大肠癌中存在P16蛋白下调和VEGF上调，P16蛋白和VEGF表达可作为反映大肠癌生物学行为的指标之一。     

Increased expression of vascular endothelial growth factor and capillary density in hearts of spontaneously hypertensive rats

OBJECTIVE: The role of VEGF in vascular remodeling of target organs exposed to chronic hypertension is poorly understood. The authors compared capillary density (CD), capillary-to-fiber ratio (C/F), and VEGF mRNA expression in the hearts (left ventricle [LV]), and skeletal muscles (soleus and anterior tibialis [AT]) of 18-week-old male spontaneously hypertensive rats (SHR) and age-matched male Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats. METHODS: CD or C/F in LV, soleus, and AT of SHR, WKY, and SD rats was determined by analysis of randomly acquired digital images of cryosections stained with FITC-conjugated GS-I lectin. VEGF mRNA expressions in the tissues were determined by Northern blot. RESULTS: VEGF mRNA expressions in LV of SHR were 3.84- and 5.05-fold higher, compared to SD and WKY rats, respectively (n = 6; p < .01). There were no significant differences in VEGF mRNA expression in soleus or AT among SHR, WKY, and SD rats (p > .05). CD in LV of SHR (4975 +/- 167) was significantly higher than WKY or SD rats, 4151 +/- 169 and 3807 +/- 187 mm(-2), respectively (p < .05). In LV of SHR, C/F increased (35%) more significantly than CD (increased 20%), compared to WKY rats. CD, or C/F in soleus or AT of SHR was similar to that observed in WKY or 8D rats. CONCLUSIONS: VEGF expression, CD, and C/F in the heart (LV) of SHR are significantly increased, compared to WKY and SD rats. The data are consistent with the possibility that VEGF may contribute to capillary growth as a compensatory response to hypertension.     

Vascular endothelial growth factor reduces Fas-mediated acute liver injury in mice

Background and Aim:  Fulminant hepatitis is still a fatal liver disease, and no specific treatment for it has been available. Vascular endothelial growth factor (VEGF) is the focus of attention because of its various actions. We investigated the effect of vascular endothelial growth factor (VEGF) on Fas-induced fulminant hepatic failure (FHF).
Method:  Male Balb/c mice were treated with an intraperitoneal injection of an anti-Fas antibody (Jo-2 Ab) with or without premedication with intraperitoneally administered human recombinant VEGF.
Results:  The serum level of alanine aminotransferase (ALT) was up to 300 times higher that of normal mice following the Jo-2 Ab injection, and histological analysis revealed hepatic injury and massive hepatocyte apoptosis. The VEGF significantly suppressed an elevation in serum ALT levels and hepatocyte apoptosis. Immunohistochemically, VEGF-treated mice showed that Bcl-xL in hepatocytes was strongly expressed.
Conclusions:  Since hepatocytes do not express VEGF receptors, we speculated that VEGF acts on sinusoidal endothelial cells (SECs) and promotes production of cytokines such as hepatocyte growth factor in SECs, resulting in reducing apoptosis through an increase expression of Bcl-xL in hepatocytes. We suggest that VEGF has a potent antiapoptotic effect on hepatocytes through cell–cell interaction between SECs and hepatocytes.     

The crucial role of vascular permeability factor/vascular endothelial growth factor in angiogenesis: a historical review

Angiogenesis is a biological process by which new capillaries are formed and it occurs in many physiological and pathological conditions. It is controlled by the net balance between molecules that have positive and negative regulatory activity and this concept had led to the notion of the 'angiogenic switch', depending on an increased production of one or more of the positive regulators of angiogenesis. Numerous inducers of angiogenesis have been identified and this review offers a historical account of the relevant literature concerning the discovery of one of the best characterized angiogenic factors, namely vascular endothelial growth factor (VEGF)/vascular permeability factor. Moreover, different strategies, designed to stimulate and to inhibit VEGF production in the context of several potential therapeutical implications, are discussed.     

畸胎瘤细胞源性生长因子和血管内皮生长因子在食管鳞癌中的表达及临床意义

目的 探讨食管鳞癌(ESCC)中畸胎瘤细胞源性生长因子(PCDGF)、血管内皮生长因子(VEGF)的表达与肿瘤临床病理参数之间的关系,明确PCDGF和VEGF在血管生成中的作用.方法 以免疫组化方法检测郑州大学第一附属医院2005年7月至2006年5 月收治的50例食管鳞癌患者手术切除标本PCDGF与VEGF的表达,并以CD105抗体标记肿瘤组织血管内皮细胞,计算肿瘤间质微血管密度(MVD).结果 食管鳞癌中PCDGF、VEGF的表达较正常食管上皮明显增加(P＜0.01);PCDGF和VEGF与肿瘤的浸润深度、TNM分期和淋巴结转移呈正相关(P均＜0.05);PCDGF、VEGF的表达与MVD值呈显著正相关(P＜0.01);PCDGF的表达与VEGF的表达呈正相关(P＜0.05).结论 PCDGF标记癌组织的敏感性较高,有望成为一种新的食管鳞癌肿瘤标志物.食管鳞癌中PCDGF、VEGF的表达与血管生成关系密切,可能通过促进肿瘤新生血管生成参与肿瘤的生长、浸润和转移.