多联机旋风式油气分离器内管与进气碰撞的数值模拟

以小型多联机用旋风式油气分离器为研究对象,建立三维稳态数值模型。气流场选用重整化群湍流模型(RNGk-ε),油滴轨迹采用随机轨道(DRW)模型,研究内管长度、筒体高度和进气碰撞程度对油气分离器内部流场分布、分离效率和压降的影响。发现大部分油滴在内管截面以上的筒体空间内完成分离;油气分离器所需内管长度与筒体高度比值随进气速度的增加而减小;进气碰撞程度(油气分离器横截面上内管下边缘与进气管上边壁的垂直距离与进气管径的比值,即h1/di)小于26.57%,进气速度大于23.09 m/s时,更容易获得稳定的旋流流场。

Expression of Angiopoietin-2 and Vascular Endothelial Growth Factor in Oral Squamous Cell Carcinoma and Its Significance

Objective： To investigate the expression of angiopoietin-2 （Ang-2） and vascular endothelialcell growth factor （VEGF） in oral squamous cell carcinoma （OSCC） and their correlations with clinicopathologic parameters, angiogenesis and vessel maturation of OSCC. Methods： The expression of Ang-2 and VEGF was detected in 41 speciments of human OSCC, 30 adjacent noncancerous oral tissues and 10 specimens of normal oral mucosa by conventional immumohistochemistry. Microvessel density （MVD） and vessel maturation index （VMI） were also assessed by double-labelling immumohistochemistry staining against CD34, a marker of pan-endothelial cells, and that against alpha-smooth muscle actin （α-SMA）, a marker of mural cells （pericytes/smooth muscle cells）. Results： The positive expression rate of Ang-2 and VEGF in 41 OSCC tissues was 51.22% and 63.42%, respectively. The expression of Ang-2 and VEGF was significantly higher in OSCC than in adjacent noncancerous oral tissues （all P〈0.05） and normal oral mucosa （all P〈0.05）. In the clinicopathologic parameters, the Ang-2 expression was closely correlated with tumor lymph node metastasis （P〈0.01） and the VEGF expression was correlated with tumor differentiated degree （P〈0.05）, but there was no significant correlation among the Ang-2 and VEGF expression and patients＇ sex, age and TNM stages （all P〉0.05）. The MVD of OSCC positive for both Ang-2 and VEGF was significantly higher than that of OSCC negative for both Ang-2 and VEGF （P〈0.05）. The VMI of OSCC positive for Ang-2 was significantly lower than that of OSCC negative for Ang-2 （P〈0.05）. When Ang-2 expression was combined with the staus of VEGF expression, MVD of OSCC positive for both Ang-2 and VEGF was the highest （51.08±2.99） as compared with that of other status in patient with OSCC （all P〈0.05）. Conclusion： The overexpression of Ang-2 and VEGF may play a crucial role in the development of OSCC. They are closely associated with angiogenesis and vessel maturation of tumor.

Correlative studies on uPA mRNA and uPAR mRNA expression with vascular endothelial growth factor, microvessel density, progression and survival time of patients with gastric cancer

AIM： To investigate the correlations between the expression of urokinase-type plasminogen activator （uPA） mRNA, uPA receptor （uPAR） mRNA and vascular endothelial growth factor （VEGF） protein and clinicopathologic features, microvessel density （MVD） and survival time. METHODS： In situ hybridization and immuno-histochemistry techniques were used to study the expressions of uPA mRNA, uPAR mRNA, VEGF and CD34 protein in 105 gastric carcinoma specimens. RESULTS： Expressions of uPA mRNA, uPAR mRNA and VEGF protein were observed in 61 （58.1%） cases, 70 （66.7%） cases and 67 （63.8%） cases, respectively. The uPA mRNA and uPAR mRNA positive expression rates in infiltrating-type cases （73.7%, 75.4%）, stage Ⅲ- Ⅳ （72.1%, 75.4%）, vessel invasion （63.2%, 69.9%）, lymphatic metastasis （67.1%, 74.4%） and distant metastasis （88.1%, 85.7%） were significantly higher than those of the expanding-type （χ^2 = 15.57, P = 0.001; χ^2 = 6.91, P = 0.046）, stage Ⅰ-Ⅱ （χ^2 = 19.22, P = 0.001; χ^2 = 16.75, P = 0.001）, non-vessel invasion （χ^2 = 11.92, P = 0.006; χ^2 = 14.15, P = 0.002）, non- lymphatic metastasis （χ^2 = 28.41, P = 0.001; χ^2 = 22.5, P = 0.005） and non-distant metastasis （χ^2 = 12.32, P = 0.004; χ^2 = 17.42, P = 0.002; χ^2 = 11.25, P = 0.012; χ^2 = 18.12, P = 0.002）.The VEGF positive expression rates in infiltrating-type cases （75.4%）, stage Ⅲ-Ⅳ （88.5%）, vessel invasion （82.9%）, lymphatic metastasis （84.3%） and distant metastasis （95.2%） were significantly higher than those of the expanding-type （χ^2 = 9.61, P = 0.021）,stage Ⅰ-Ⅱ （χ^2 = 16.66, P = 0.001）, non-vessel invasion （χ^2 = 29.38, P = 0.001）, non-lymphatic metastasis （χ^2 = 18.68, P = 0.005）, and non-distant metastasis （χ^2 = 22.72, P = 0.007; χ^2 = 21.62, P = 0.004）. The mean MVD in the specimens positive for the uPA mRNA, uPAR mRNA and VEGF protein was markedly higher than those with negative expression groups. Moreover, a positive relation between MVD and uPA mRNA （rs = 0.199, P = 0.042）, uPAR mRNA （rs = 0.278, P = 0.035）, and VEGF （rs = 0.398, P = 0.048） expressions was observed. The mean survival time in cases with positive uPA mRNA, uPAR mRNA and VEGF protein expression or MVD value ≥54.9 was significantly shorter than those in cases with negative expression or MVD value 〈 54.9. CONCLUSION： uPA and uPAR expressions are correlated with enhanced VEGF-induced tumor angiogenesis and may play a role in invasion and nodal metastasis of gastric carcinoma, thereby serving as prognostic markers of gastric cancer.

Association of serum vascular endothelial growth factor-C and lymphatic vessel density with lymph node metastasis and prognosis of patients with gastric cancer

AIM： To investigate whether serum vascular endothelial growth factor-C （SVEGF-C）, VEGF-C, and lymphatic vessel density （LVD） in tumor tissues are related to lymph node metastasis （LNM） and prognosis in gastric cancer. METHODS： SVEGF-C levels of 80 gastric cancer patients and 20 healthy donors were examined using ELISA. VEGF-C expression and LVD were examined using immunohistochemical staining. Kaplan-Meier survival analysis was performed to determine their influence on the prognosis of the patients. RESULTS： The SVEGF-C level in gastric cancer patients （595.9 ± 201.0 ng/L） was significantly higher （P = 0.000） than controls （360.0 ± 97.4 ng/L）. Both SVEGF-C and LVD were significantly higher in poorly differentiated adenocarcinomas, T3 and T4, LNM, distant metastasis, and pTNM groups Ⅲ and Ⅳ （P = 0.000）. The sensitivity and specificity of SVEGF-C for predicting LNM were 82.8% and 81.8%, respectively （cut-off = 542.5 ng/L）. The positive expression rate of VEGF-C was significantly higher in cancerous than in normal tissues （65% vs 20%; P = 0.001）. VEGF-C expression up-regulation was significantly related to differentiation, depth of invasion, LNM, distant metastasis, and pTNM stage （P = 0.000）. LVD was 10.7 ± 3.1/200 HP in the experimental group vs 4.9 ± 1.3/200 HP in controls （P = 0.000）; LVD in cancerous tissues with and without LNM was 12.0 ± 2.7/200 HP vs 7.6 ± 0.5/200 HP, respectively （P = 0.000）. SVEGF-C and LVD were significantly higher in VEGF-C positive than in negative patients （P = 0.000）; SVEGF-C level was related to LVD （P = 0.000）. Kaplan-Meier survival analysis factors predicating poor prognosis were： SVEGF-C level （P = 0.001）, VEGF-C expression and LVD （both P = 0.000）. CONCLUSION： SVEGF-C level, VEGF-C and LVD are related to LNI and poor prognosis of patients with gastric cancer, SVEGF-C may be a biomarker for LNI in gastric cancer,

Hypoxia training attenuates left ventricular remodeling in rabbit with myocardial infarction

Objective Previous studies showed that hypoxia preconditioning could protect cardiac function against subsequent myo-cardial infarction injury. However, the effect of hypoxia on left ventricular after myocardial infarction is still unclear. This study therefore aims to investigate the effects of hypoxia training on left ventricular remodeling in rabbits post myocardial infarction. Methods Adult male rabbits were randomly divided into three groups： group SO （sham operated）, group MI （myocardial infarc-tion only） and group MI-HT （myocardial infarction plus hypoxia training）. Myocardial infarction was induced by left ventricular branch ligation. Hypoxia training was performed in a hypobaric chamber （having equivalent condition at an altitude of 4000 m, FiO214.9%） for 1 h/day, 5 days/week for four weeks. At the endpoints, vascular endothelial growth factor （VEGF） in the plasma was measured. Infarct size and capillary density were detected by histology. Left ventricular remodeling and function were as-sessed by echocardiography.Results After the 4-week experiment, compared with the group SO, plasma VEGF levels in groups MI （130.27 ± 18.58 pg/mL,P〈 0.01） and MI-HT （181.93 ± 20.29 pg/mL,P〈 0.01） were significantly increased. Infarct size in Group MI-HT （29.67% ± 7.73%） was deceased remarkably, while its capillary density （816.0 ± 122.2/mm2） was significantly increased. For both groups MI and MI-HT, left ventricular end-diastolic and end-systolic dimensions were increased whereas left ventricular ejection fraction was decreased. However, compared with group MI, group MI-HT diminished left ventricular end-diastolic （15.86 ± 1.09 mm,P〈 0.05） and end-systolic dimensions （12.10 ± 1.20 mm,P〈 0.01） significantly and im-proved left ventricular ejection fraction （54.39 ± 12.74 mm,P〈 0.05）.ConclusionHypoxia training may improve left ven-tricular function and reduce remodeling via angiogenesis in rabbits with MI.

Prognostic significance of erythropoietin and erythropoietin receptor in gastric adenocarcinoma

AIM: To investigate the expression of Erythropoietin (Epo) and its receptor (EpoR) in gastric adenocarcinoma (GAC) and the correlation with angiogenesis and clinicopathological features. METHODS: The expressions of Epo, EpoR and vascular endothelial growth factor (VEGF), as well as mi-crovessel density were evaluated in 172 GAC biopsies by immunohistochemical staining. The correlations between these parameters and patient’s clinicopathological features were analyzed statistically. RESULTS: The proportion of Epo and EpoR alterations in GAC was higher than that in adjacent normal mucosa (P = 0.035 and 0.030). Epo high-expression was associ-ated with EpoR high-expression, Lauren type, extensivelymph node metastasis and advanced stage of GAC (P = 0.018, 0.018, 0.004 and 0), while EpoR expression was linked with older age, World Health Organization type, extensive lymph node metastasis and advanced stage (P = 0.001, 0.013, 0.008 and 0.001). VEGF high expression was significantly correlated with EpoR low-expression, Lauren type, extensive lymph node metastasis and advanced stage (P = 0.001, 0.001, 0.001 and 0.007). The expression of Epo or EpoR was associated with microvessel density (P = 0.004 and 0.046). On multivariate analysis, only lymph node metastasis, abnormal Epo expression and tumor nodes metastases stage were independently associated with survival. In addition, a strong association with the immunohistochemical expression of EpoR and the angiogenic protein, VEGF, was noted. CONCLUSION: Increased expression of Epo and EpoR may play a signif icant role in the carcinogenesis, angiogenesis and progression of GAC. Epo may be an inde-pendent prognostic factor.

The effects of vascular endothelial growth factor and microvessel density in the fibromyoma uteri

Objective： To investigate vascular endothelial growth factor （VEGF） expression and microvessel density （MVD） on the fibromyoma uteri treated with mifepristone. Methods： VEGF expression and MVD were counted on 60 cases of the fibromyoma uteri by SP method, including 40 cases of mifepristone treated and 20 cases of untreated patients as controlled group. Results： VEGF positive expression rate and MVD in treated group were 3715% and 9.90 ＋ 5.95, which were lower than those in controlled group （80% and 16.36 ＋ 2.07; P 〈 0.05）. Meanwhile, in treated group, those in marked shrink in tumor size sub-group were lower than in not obvious sub-group （12.0% and 7.89 ＋ 4.36 vs. 80% and 11,29 ＋ 3.10; P 〈 0.05）. Conclusion： VEGF and MVD expression decreases in the fibromyoma uteri after treatment with mifepristone, suggesting that mifepristone could inhibit angiogenesis and blood supply resulting in tumor shrink.

Vascular endothelial growth factor and microvessel density for detection and prognostic evaluation of invasive breast cancer

Objective The purpose of this study was to evaluate the distribution of vascular endothelial growth factor （VEGF） and CD105-microvessel density （MVD）in invasive breast carcinomas. We also aimed to analyze the relationship between VEGF and MVD expression with other standard prognostic parameters associated with invasive breast cancer, such as size, grade, stage of the cancer, metastases, and tumor recurrence. Methods immunohistochemistry via the Ultra SensitiveTM S-P method was used to detect VEGF and MVD expression in 128 cases of invasive breast carcinoma. Specimens were evaluated for CD105 expression. Positively stained microvessels were counted in dense vascular loci under 400x magnification, MVD in the peripheral area adjacent to the lesion and in the central, area within the lesion in invasive breast carcinomas and benign leisions groups were also assessed. Fifty cases of benign breast disease tissue were selected as the control group. Results Results showed that 64.1% of invasive breast cancer samples were VEGF-positive, higher than in benign breast disease tissue （22.0%, P 〈 0.05）. There was a positive correlation between VEGF overexpression and histological grade, lymph node metastasis, and distant metastasis of invasive breast cancer. VEGF expression was not related to age or size of the tumor （P 〉 0.05）. MVD of the peripheral area adjacent to the lesion was significantly higher than those central area within the lesion in both invasive breast cancer and benignbreast disease groups （P 〈 0.01 for each group）. There were significant differences in the mean CD105-MVD, between invasive breast tumors with a histological grade of Ⅰ or Ⅱ and grade Ⅲ; between tumors with lymph node or distant metastasis; and between patients with or without recurrence （P 〈 0.05）. However, there was no difference in the mean MVD between the two age groups （≤ 50 years vs. 〉 50 years） or the two tumor diameter groups （〈 2 cm vs. 〉 2 cm）, P 〉 0.05. Conclusion Overexpression of VEGF and MVD may be important biological.markers for invasion and lymph node and distant metastases of invasive breast cancer. Combined detection of the two tumor markers could provide better prognostic monitoring for disease recurrence and metastasis, as well as aid with clinical staging of breast tumors. Prediction of the risk for metastasis and recurrence, as well as recurrence patterns based on VEGF and MVD post-surgery, could aid design of better follow-up regimens and appropriate treatment strategies for breast cancer patients.