血管内皮生长因子缓释微粒的合成与制备

目的 探讨乳化-分散法合成与制备血管内皮生长因子缓释微粒的效果。方法 采用乳化-分散法，使用可生物降解高分子聚乳酸／乙醇酸共聚物(PLGA)对血管内皮生长因子(VEGF)进行包裹，制成可控制释放的微粒。结果 此方法制得了0.2～0．33μm的含VEGF的缓释微粒。结论 乳化-分散法是合成与制备血管内皮生长因子缓释微粒的较好方法之一。     

血管内皮生长因子缓释微粒的合成与制备

目的 探讨乳化-分散法合成与制备血管内皮生长因子缓释微粒的效果。方法 采用乳化-分散法,使用可生物降解高分子聚乳酸/乙醇酸共聚物(PLGA)对血管内皮生长因子(VEGF)进行包裹,制成可控制释放的微粒。结果 此方法制得了0.2～0.33μm的含VEGF的缓释微粒。结论 乳化-分散法是合成与制备血管内皮生长因子缓释微粒的较好方法之一。     

rh-BMP-2壳聚糖微球的制备及体外检测

[目的]以壳聚糖为辅料,通过乳化交联法制备新型重组人骨形态发生蛋白-2缓释微球,并对其粒径、载药、体外释药、理化特性及降解特性进行检测,以评估应用生物可降解的壳聚糖微球作为BMP-2缓释载体的可行性.[方法]以京尼平作为交联剂,应用乳化交联法制备具有控制释放功能的负载rhBMP-2壳聚糖微球,应用扫描电镜观察微球的形态和粒径;利用酶联免疫吸附实验(ELISA)动态检测BMP-2壳聚糖微球的载药率、包封率和缓释规律以分析微球的缓释能力.[结果]乳化交联法制备的壳聚糖微球,球形良好,球体表面光滑,具有较高的包封率(>85%).体外药物释放试验表明,rhBMP-2可以从壳聚糖微球中缓慢释放,整个释放过程可达30 d.[结论]应用乳化交联法制备的负载rhBMP-2壳聚糖缓释微球,具有很好的控制释放rhBMP-2的能力.这种新型药物控制释放系统在细胞因子的控制释放及骨组织工程中有潜在的应用价值.     

阿仑膦酸钠明胶纳米微粒制备和体外释药试验

目的探索阿仑膦酸钠明胶纳米微粒的制备方法，观察其体外缓释和酶降解释药的效果，并探讨其作为新型阿仑膦酸钠制剂的应用前景。方法采用凝聚相分离法制备阿仑膦酸钠明胶纳米微粒，磷钼兰比色法测定其载药率和包封率及体外缓释能力，建立酶降解释药曲线，测定其降解性。结果载药明胶纳米微粒平均粒径在100～200nm之间；载药率为2．14％，包封率为56．73％；在生理盐水中的释药规律符合一级动力学方程，t1/2为36.75min；胰蛋白酶对纳米微粒的降解作用持续时间较长（300min），并能够完全降解纳米微粒。结论阿仑膦酸钠明胶纳米微粒具有大小适中、缓释效果好和易降解的特点，具有良好的临床应用前景。     

一氧化氮合酶抑制剂对延缓腰椎间盘退变的影响

目的　探讨一氧化氮合酶(NOS)抑制剂L N6 亚氨乙基 赖氨酸(L NIL)和S 甲基异硫脲(SMT)对退变腰椎间盘组织代谢的影响。方法　无菌条件下,取2 0例腰椎间盘突出症患者的椎间盘组织体外培养,分别加入1mmol/L浓度的SMT和L NIL ,培养72h后,通过检测硝酸盐和亚硝酸盐的含量来观察椎间盘NO的释放量及NOS的活性;原位杂交法检测椎间盘组织iNOSmRNA和MMP3mRNA的表达。培养10d后,化学比色法观察椎间盘蛋白多糖含量和羟脯氨酸释放量的变化。结果　L NIL组髓核和纤维环NO释放量(65 .6±4.5 ,68.8±5 .7) μmol/L和SMT组髓核和纤维环NO释放量(69.5±6.5 ,69.1±6.1) μmol/L较对照组NO释放量(10 7.9±4.4,93 .1±5 .9) μmol/L明显减少(P <0 .0 1)。L NIL组和SMT组髓核组织中蛋白多糖含量(5 1.3±9.6,48.2±8.5 )kg/L ,比对照组(3 2 .1±6.4)kg/L明显增加(P <0 .0 1) ,羟脯氨酸释放量(1.1±0 .4,1.2±0 .5 )kg/L比对照组(3 .4±0 .8)kg/L显著减少(P <0 .0 1) ;同时,原位杂交法未检测到iNOSmRNA和MMP3mRNA的表达。结论　NOS抑制剂L NIL和SMT能抑制过量NO的释放,对延缓椎间盘退变具有积极的作用     

血管内皮因子、人表皮生长因子、碱性成纤维细胞生长因子纳米缓释剂对血管内皮细胞影响的比较

目的制备血管内皮生长因子(VEGF)、碱性成纤维细胞生长因子(bFGF)、人表皮生长因子(EGF)可降解缓释微球,考察其生物活性的保存情况,以及它们对血管内皮细胞的作用.方法采用改良的乳化冷凝法交联制备VEGF、bFGF、EGF的明胶缓释微球,将它们加入血管内皮细胞的培养液中,用细胞计数法、四甲基偶氮唑盐微量反应比色法(MTT法)测定细胞增殖情况.结果VEGF、bFGF、EGF的缓释微球平均粒径(11.32±3.64)μm;培养1天后各组细胞计数、吸光度(A)值差异均无显著性;5天后,VEGF20ng缓释微球组细胞计数、吸光度(A)值明显高于其它组;7天后,VEGF20ng缓释微球组值仍高于其它组,但差异无显著性.结论VEGF、bFGF、EGF的缓释微球制备工艺简便,成球性好;能较长时间地持续释放活性VEGF,bFGF、EGF,可促进血管内皮细胞的增殖,其中VEGF效果最显著.     

生长因子缓释微球的制备及其对内皮细胞的影响

目的:制备碱性成纤维细胞生长因子(bFGF)、血管内皮细胞生长因子(VEGF)可降解缓释微球,考察其生物活性的保存情况及它们对内皮细胞的作用。方法:采用改良的乳化冷凝法交联制备复合bFGF、VEGF的明胶缓释微球,将它们加入内皮细胞的培养液中,用细胞计数法、四甲基偶氮唑盐微量反应比色法(MTT法)测定细胞增殖情况。结果:复合bFGF、VEGF的缓释微球平均粒径(11.32±3.64)μm;培养1天后各组细胞计数、吸光度(A)值差异均无显著性;5天后两种生长因子缓释微球组细胞计数、吸光度(A)值明显高于对照组;7天后两种生长因子缓释微球组值仍高于其它组。结论:复合bFGF、VEGF的缓释微球制备工艺简便,具有良好的缓释活性能较长时间地持续释放活性bFGF、VEGF,可明显促进内皮细胞的增殖。     

硬脂酸聚乙二醇阿霉素纳米粒的制备及其对人肝癌细胞的杀伤作用

目的合成硬脂酸聚乙二醇阿霉素纳米微粒(DOX鄄SLNs鄄PEG)并检测其相关参数,观察其对人肝癌细胞杀伤作用。方法以“乳化蒸发鄄低温固化”法合成DOX鄄SLNs鄄PEG纳米粒。透射电镜计算粒径,分光光度法计算载药率,噻唑蓝法(MTT法)观察对肝癌细胞的体外杀伤效应及观察体内抑瘤效应。结果DOX鄄SLNs鄄PEG纳米粒平均粒径120±4.84mm,包封率68.6%,体外释放实验提示,7d可释放所载60%左右的药物。体内抑瘤实验表明:控释制剂间隔给药疗效已优于未包载药物每日给药的疗效,量效关系明显。结论DOX鄄SLNs鄄PEG纳米粒可有效抑制肝癌细胞的生长。     

三步酶消化法高效分离兔原代关节软骨细胞及体外培养观察

目的　观察设计的三步酶消化法分离原代关节软骨细胞的效果,并对体外培养不同代次细胞的生物学活性进行评价。方法　三步酶消化法设计为以培养液配制的1g/L胰蛋白酶及1g/LEDTA混合液、1g/L透明质酸酶和2g/LⅠ型胶原酶顺序消化关节软骨分离细胞,检测细胞收获效率和存活率;体外传代培养观察细胞形态、生长及胞外基质中Ⅰ型和Ⅱ型胶原、蛋白多糖聚集体等的变化。结果　(1)关节软骨经三步酶消化基质逐步解离和降解,细胞得以完全释放和分离,每克软骨的细胞收获量平均为50 3×106 个细胞,细胞存活率平均为98. 8%。(2)原代和第一代细胞附壁生长呈三角形或多角形,生长融合时呈卵圆形,Ⅱ型胶原免疫组化和甲苯胺蓝异染反应均呈阳性,原代细胞外基质有高的硫酸糖胺多糖含量为(92±10)μg/cm2;第三代后细胞逐渐变为梭形,Ⅱ型胶原免疫组化为阴性,甲苯胺蓝异染反应明显减弱,第四代细胞外基质的硫酸糖胺多糖含量为(48±12)μg/cm2。结论　(1)三步酶消化法可使关节软骨基质完全消化降解,具有高细胞收获率、高细胞存活率和操作简便等特点。(2)原代和第一代软骨细胞具有良好的生物学活性,而第三代以后的细胞生物学活性低下。     

硬脂酸阿霉素纳米粒的制备及在抗肝癌中的应用

目的　合成硬脂酸聚乙二醇阿霉素纳米微粒(doxorubicin solid lipid nanoparticles polyethylene glycol, DOX SLNs PEG)并检测其相关参数,观察其对人肝癌细胞杀伤作用。方法　以“乳化蒸发 低温固化”法合成 DOX SLNs PEG 纳米粒,透射电镜计算粒径,分光光度法计算载药率,MTT法观察对肝癌细胞的体外杀伤作用。结果　DOX SLNs PEG 纳米粒平均粒径( 120±4 84) mm,包封率68 6%,体外释放实验提示,7 d可释放所载60%左右的药物;体内抑瘤实验表明:控释制剂间隔给药疗效已优于未包载药物每日给药的疗效,量效关系明显。结论　DOX SLNs PEG纳米粒可有效抑制肝癌细胞的生长。     

Vascular endothelial growth factor and its soluble receptor, Flt-1, are not correlated to erythropoietin in diabetics with normal or reduced renal function

BACKGROUND AND AIMS: Recombinant erythropoietin upregulates the expression of the vascular endothelial growth factor (VEGF) receptors, Flt-1 (VEGFR-1) and KDR/Flk-1 (VEGFR-2), in endothelial cells. The integrity of the VEGF system seems to be crucial for the regulation of endothelial permeability and thus for the avoidance of renal protein leakage. As albuminuria/proteinuria is a hallmark of diabetic nephropathy, we examined cross-sectionally in 35 type 1 and 37 type 2 diabetic patients with various degrees of renal dysfunction and albuminuria whether there was an interrelationship between intrinsic erythropoietin (EPO) and VEGF/Flt-1. METHODS AND RESULTS: In patients with plasma creatinine values < or =1.5 (n = 53) or >1.5 mg/dL (n = 19), the mean serum EPO was 5.6 +/- 4.4 and 10.2 +/- 7.0 mU/mL (P = 0.02), respectively. In the two groups, urinary and serum VEGF(165) concentrations were similarly distributed (mean 94.3 +/- 91.8 vs 108 +/- 72.2 ng/L and 91.7 +/- 76.8 vs 91.9 +/- 74.9 ng/L, respectively; both P = NS). The mean urinary Flt-1 for the two groups amounted to 0.14 +/- 0.35 and 0.51 +/- 0.93 ng/mL (P = 0.045), respectively. No correlation between VEGF or Flt-1 and EPO was apparent. CONCLUSION: Our data suggest that in vivo EPO does not affect the functionality and/or production of components of the VEGF/Flt-1 system in diabetics with normal or reduced renal function.     

VEGF scaffolds enhance angiogenesis and bone regeneration in irradiated osseous defects.

Bone regeneration is challenging in sites where the blood supply has been compromised by radiation. We examined the potential of a growth factor (VEGF) delivery system to enhance angiogenesis and bone formation in irradiated calvarial defects. VEGF-releasing polymers significantly increased blood vessel density and vascular perfusion in irradiated defects and increased bone formation relative to control conditions. INTRODUCTION: Radiation therapy causes damage to tissues and inhibits its regenerative capacity. Tissue injury from radiation is in large part caused by a compromised vascular supply and reduced perfusion of tissues. The aim of this study was to determine if delivery of vascular endothelial growth factor (VEGF) from a biodegradable PLGA (copolymer of D,L-lactide and glycolide) scaffold could enhance neovascularization and bone regeneration in irradiated osseous defects. MATERIALS AND METHODS: An isolated area of the calvarium of Fisher rats was irradiated (12 Gy) 2 weeks preoperatively, and two 3.5-mm osseous defects were created in this area, followed by the placement of PLGA scaffolds or VEGF scaffolds (PLGA scaffolds with incorporated VEGF) into the defects. Laser Doppler perfusion imaging was performed to measure perfusion of these areas at 1, 2, and 6 weeks. Implants were retrieved at 2, 6, and 12 weeks, and histologic and muCT analyses were performed to determine neovascularization and bone regeneration. RESULTS: Histological analyses revealed statistically significant increases in blood vessel formation (>2-fold) and function (30%) within the VEGF scaffolds compared with PLGA scaffolds. Additionally, evaluation of bone regeneration through bone histomorphometric and muCT analyses revealed significantly greater bone coverage (26.36 +/- 6.91% versus 7.05 +/- 2.09% [SD]) and increased BMD (130.80 +/- 58.05 versus 71.28 +/- 42.94 mg/cm(3)) in VEGF scaffolds compared with PLGA scaffolds. CONCLUSIONS: Our findings show that VEGF scaffolds have the ability to enhance neovascularization and bone regeneration in irradiated osseous defects, outlining a novel approach for engineering tissues in hypovascular environments.     

烧伤创面与糖尿病溃疡创面的比较

目的比较烧伤创面与糖尿病溃疡创面的差异，初步分析糖尿病患者溃疡创面难愈的机制。方法分别切取非糖尿病烧伤患者的足部创面（对照组）和糖尿病患者的足部溃疡创面（试验组）组织，行组织块培养。用酶联免疫吸附测定（ELISA）法、反转录-PCR法分别检测创面组织释放的成纤维细胞生长因子2（FGF2）、血管内皮生长因子（VEGF）蛋白质及其mRNA水平；免疫组织化学法检测创面微血管密度（MVD）的变化。人脐静脉内皮细胞分别在含5mmol／L葡萄糖的培养液（正常培养液组）、含30mmol／L葡萄糖的培养液（高糖组）、含30mmol／L甘露醇的培养液（甘露醇组）中培养7d，以ELISA法测定VEGF蛋白质水平。结果对照组患者FGF2、VEGF蛋白质水平分别为（59±3）ng／ml、（56±7）pg／ml，试验组2种蛋白质水平分别为（89±6）ng／ml、（108±5）pg／ml，组间比较差异均有统计学意义（P〈0．05或P〈0．01），mRNA比较结果与蛋白质相似；2组的MVD水平，差异亦有统计学意义（P〈0．05）。体外细胞培养时当培养液含FGF2，高糖组与正常培养液组的VEGF蛋白质水平相近（P〉0．05）；移去FGF2后2、5d，正常培养液组该指标明显高于高糖组（P〈0．05或P〈0．01）。结论糖尿病患者溃疡创面难愈与血管化受到抑制以及调控血管生长的因子低表达密切相关。     

自体富血小板凝胶的制备及其生长因子分析

目的 探讨不同离心方法 制备自体富血小板凝胶(autologous platelet-rich gel,APG)的方法 ,通过改变离心速度比较不同的离心力对PLT富集的影响分析全血和APG中5种生长因子浓度.方法 对13例糖尿病难治性皮肤溃疡患者行APG治疗.取11例自身外周静脉血,分别用3种离心速度制备富血小板血浆(platelet-rich plasma,PRP).A组(n=6)先以529×g离心4 min,再以854×g离心6 minB组(n=5)先以313×g离心4 min,再以1252×g离心6 min;C组(n=5)先以176×g离心5 min,再以1 252×g离心5 min.将离心后制得的PRP与凝血酶.钙剂以101混合凝固后制备APG,用于患者皮肤溃疡的治疗.采用全自动血细胞分析仪计数各组全血和PRP中PLT数量.采用酶联免疫吸附法测定全血和APG中PDGF.BB、VEGF、IGF.1、EGF和TGF.a1 5种生长因子浓度.结果 A组PRP中PLT数量为(779.67±352.39)×109/L,较全血的(263.50±76.63)×109/L提高(2.98±1.42)倍,差异有统计学意义(P＜0.05);PLT回收率为51.5%±22.2%.B组PRP中PLT数量最高,为(1363.80±919.74)X 109/L,较全血的(232.80±127.99)×109/L提高(5.91±2.04)倍,差异有统计学意义(P＜0.05);PLT回收率为75.2%±21.0%,明显高于A组(P＜0.05).全血和APG中PDGF-BB、EGF、IGF-1以及TGF-a.浓度分别为(145.94±133.24)、(503.81±197.86)pg/mL,(160.73±71.10)、(265.95±138.43)pg/mL,(14.54±35.34)、(110.56±84.36)ng/mL,(3.31±2.27)、(5.67±4.80)ng/mL,差异有统计学意义(P＜0.05);VEGF浓度升高,两者间差异无统计学意义(P＞0.05).对数转换后的PLT数量与PDGF-BB、TGF-a1浓度成正相关,相关系数r分别为0.627和0.437(P＜0.05).13例患者共行18次APG治疗,其中9例治疗12周溃疡愈合,愈合率为69.2%;10例窦道愈合,愈合率为83.3%.结论 以313×g离心4 min,再以1252×g离心6 min是制备PRP的最佳方法 ;APG中生长因子浓度高于全血;PLT数量与PDGF-BB、TGF-a1浓度成正相关.     

Serum von Willebrand factor,matrix metalloproteinase-9, and vascular endothelial growth factor levels predict the onset of cerebral vasospasm after aneurysmal subarachnoid hemorrhage

OBJECTIVE: Endothelial damage and intimal proliferation occur in vasospastic cerebral arteries after subarachnoid hemorrhage (SAH). In the peripheral vasculature, endothelial damage increases intimal matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF) levels, causing neointimal proliferation. We hypothesized that serum von Willebrand factor (vWF) (a marker of endothelial cell death), MMP-9, and VEGF levels could serve as prognostic markers in predicting the occurrence of cerebral vasospasm. METHODS: Venous serum vWF, MMP-9, and VEGF levels were prospectively measured daily, for 12 days or until the onset of vasospasm, for 45 consecutive patients admitted with SAH (n = 38) or admitted for elective aneurysm clipping (control subjects, n = 7). The development of transcranial Doppler flow velocities of more than 180 cm/s and/or new focal neurological deficits with angiographically confirmed vasospasm was considered the onset of vasospasm. To establish whether these markers were specific for vasospasm versus ischemia, blood samples were obtained from a concurrent group of 42 patients within 24 hours after stroke onset unrelated to SAH. RESULTS: Fifty-seven percent of patients (22 of 38 patients) developed vasospasm, 4 to 11 days after SAH (median, 7 d). Mean peak serum vWF, MMP-9, and VEGF levels were increased in the SAH prevasospasm cohort, compared with the SAH nonvasospasm cohort (vWF, 5526 +/- 929 versus 4934 +/- 599 ng/ml, P = 0.01; MMP-9, 705 +/- 338 versus 438 +/- 154 ng/ml, P = 0.006; VEGF, 0.12 +/- 0.06 versus 0.06 +/- 0.06 ng/ml, P = 0.023). Mean peak vWF, MMP-9, and VEGF levels for the focal ischemia cohort (vWF, 4645 +/- 875 ng/ml, P = 0.01; MMP-9, 250 +/- 308 ng/ml, P = 0.001; VEGF, 0.03 +/- 0.04 ng/ml, P = 0.001) were markedly lower in comparison with the SAH prevasospasm cohort and were unchanged in comparison with the control cohort. vWF levels of more than 5500 ng/ml, VEGF levels of more than 0.12 ng/ml, and MMP levels of more than 700 ng/ml each independently increased the odds of subsequent vasospasm (18-, 20-, and 25-fold, respectively). CONCLUSION: The development of cerebral vasospasm after SAH was preceded by increases in serum vWF, MMP-9, and VEGF levels. Increased serum vWF, MMP-9, and VEGF levels could accurately predict the onset of cerebral vasospasm after SAH. These factors were not elevated by SAH alone or in a separate cohort of patients with ischemic stroke, suggesting that these factors might play a role in the pathogenesis of human cerebral vasospasm.     

Early changes of endothelin,nitric oxide and arginine—vasopressin in patients with acute cerebral injury

OBJECTIVE: To investigate the early changes and clinical significance of plasma endothelin (ET), nitric oxide (NO) and arginine-vasopressin (AVP) in patients with acute moderate or severe cerebral injury. METHODS: The early (at 24 hours after injury) plasma concentrations of ET, NO and AVP were measured with radioimmunoassay and Green technique in 48 cases of acute moderate (GCS8 in 21 cases) cerebral injury (Group A), in 42 cases of non-cerebral injury (Group B) and in 38 normal individuals (Group C), respectively. RESULTS: The early plasma concentrations of ET (109.73 ng/L+/-12.61 ng/L), NO (92.82 micromol/L+/-18.21 micromol/L ) and AVP (49.78 ng/L+/-14.29 ng/L) in Group A were higher than those in Group B (67.90 ng/L+/-11.33 ng/L, 52.66 micromol/L+/-12.82 micromol/L and 29.93 ng/L+/-12.11 ng/L, respectively, P<0.01) and Group C (50.65 ng/L+/-17.12 ng/L, 36.12 micromol/L+/-2.16 micromol/L and 5.18 ng/L+/-4.18 ng/L, respectively, P<0.001 ). The amounts of ET, NO and AVP in patients with severe cerebral injury were 116.18 ng/L+/-18.12 ng/L, 108.19 micromol/L+/-13.28 micromol/L and 58.13 ng/L+/-16.78 ng/L, respectively, which were significantly higher than that of the patients with moderate cerebral injury (92.33 ng/L+/-16.32 ng/L, 76.38 micromol/L+/-12.71 micromol/L and 36.18 ng/L+/-12.13 ng/L respectively, P<0.01 ). The early levels of ET, NO and AVP in Group A were negatively related to the GCS scales. The amounts of ET, NO and AVP were 126.23 ng/L+/-15.23 ng/L, 118.18 micromol/L+/-10.12 micromol/L and 63.49 ng/L+/-14.36 ng/L respectively in patients with subdural hematoma, which were significantly higher than those in patients with epidural hematoma (81.13 ng/L+/-12.37 ng/L, 68.02 micromol/L+/-13.18 micromol/L and 45.63 ng/L+/-12.41 ng/L respectively, P<0.01). The plasma concentrations of ET, NO and AVP in stable duration (at 336 hours after injury) in Group A and Group B were similar to those in Group C. CONCLUSIONS: ET, NO and AVP were related to the pathophysiological process that occurs in the early stage of acute cerebral injury and the values of ET, NO and AVP correlate positively with the clinical manifestations. The changes of plasma ET, NO and AVP can be regarded as important indices to assess the severity of acute cerebral injury.     

Early changes of arginine vasopressin and angiotensin Ⅱ in patients with acute cerebral injury

OBJECTIVE: To study the changes and clinical significance of arginine vasopressin (AVP) and angiotensin II (AT-II) in patients with acute moderate and severe cerebral injury. METHODS: The early plasma concentration was checked by radioimmunoassay in 47 cases of acute moderate and severe cerebral injury, 30 cases of non-cerebral injury and 30 healthy volunteers. RESULTS: The early plasma concentrations of AVP (50.23 ng/L +/- 15.31 ng/L) and AT-II (248.18 ng/L +/- 82.47 ng/L) in cerebral injury group were higher than those in non-cerebral injury group (AVP for 30.91 ng/L +/- 11.48 ng/L and AT-II for 120.67 ng/L +/- 42.49 ng/L, P<0.01). The early plasma concentrations of AVP and AT-II in cerebral injury group were also obviously higher than those of the volunteers (AVP for 5.16 ng/L +/- 4.23 ng/L and AT-II for 43.11 ng/L +/- 16.39 ng /L, P<0.001). At the same time, the early plasma level of AVP (58.90 ng/L +/- 18.12 ng/L) and AT-II (292.13 ng/L +/- 101.17 ng/ L) was higher in severe cerebral injured patients than moderate cerebral injured ones (AVP for 36.68 ng/L +/- 12.16 ng/L and AT-II for 201.42 ng/L +/- 66.10 ng/L, P<0.01). The early level of AVP and AT-II was negatively related to the GCS scales in acute cerebral injury. The early plasma concentrations of AVP (45.98 ng/L +/- 13.48 ng/L) and AT-II (263. 28 ng/L +/- 80.23 ng/L) were lower in epidural hematoma group than those of subdural hematoma and cerebral injury group (AVP for 64.12 ng/L +/- 15.56 ng /L and AT-II for 319.82 ng/L +/- 108.11 ng/L, P<0. 01). CONCLUSIONS: AVP and AT-II may play an important role in pathophysiologic process in the secondary cerebral injury. The more severe the cerebral injury is, the higher the early level of AVP and AT-II will be. The early plasma level of AVP and AT-II may be one of the severity indexes of cerebral injury.     

Vascular endothelial growth factor stimulates a novel calcium-signaling pathway in vascular smooth muscle cells

BACKGROUND: Vascular endothelial growth factor (VEGF) is a potent vascular mitogen that selectively stimulates vascular smooth muscle cell (VSMC) migration through an unknown mechanism while having no effect on VSMC proliferation. It is known that VSMC migration and proliferation are dependent on the second messenger Ca2+ and, in particular, mitogen-stimulated Ca2+ influx. We hypothesized that the selective effect of VEGF on VSMC migration versus proliferation was a result of differential VEGF-stimulated Ca2+ signaling pathways. METHODS: Primary cultured human aortic smooth muscle cells (VSMCs) were grown to subconfluency and assigned to the following experimental groups: no stimulation, stimulation with platelet-derived growth factor-BB (PDGF-BB) (20 ng/mL) as positive control, and stimulation with VEGF165 (40 ng/mL). Total increase in [Ca2+]cyt and intracellular calcium release was quantified with the use of a fura-2 fluorescence assay. Assays for the following receptors VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1) and PDGFR-beta were performed by immunoprecipitation, while PLCgamma1, Akt 1/2, and phospholamban B phosphorylation were assessed with Western immunoblotting. RESULTS: VSMCs stimulated with VEGF165 exhibited no intracellular Ca2+ release, compared with a 75 +/- 30 nmol/L intracellular calcium release after PDGF-BB stimulation, (P < .02) VEGF165-stimulated VSMCs in Ca2+-containing media exhibited 192 +/- 26 nmol/L increase in [Ca2+]cyt, compared with 354 +/- 54 nmol/L increase after PDGF-BB stimulation (P < .02). VEGF165 did not phosphorylate PLCgamma1 after 1, 5, or 10 minutes of treatment. VEGF165 treatment did not result in PI3-K/Akt activation at 1-, 5-, or 10-minute time points. Calmodulin-dependent kinase II (CaMKII) was activated by both VEGF165 and PDGF-BB after 1 and 5 minutes of stimulation. The presence of the receptors VEGFR-1, VEGFR-2, and PDGFR-beta was confirmed in all experimental groups. CONCLUSIONS: VEGF induces extracellular calcium influx but no intracellular calcium release in VSMCs. This lack of intracellular Ca2+ release stems from the inability of VEGF165 to activate the PLCgamma1 cascade and IP3 receptor-mediated Ca2+ release. The lack of PI3-K/Akt activation at these time points indicates a novel extracellular Ca2+ influx pathway sufficient to activate CaMKII. A paradigm relating extracellular Ca2+ influx to CaMKII activation and migration is suggested and may account for the selective effects of VEGF on VSMC migration.     

Vascular endothelial growth factor is increased in cerebrospinal fluid after traumatic brain injury in infants and children

OBJECTIVE: Vascular endothelial growth factor (VEGF) is an important regulator of angiogenesis, the formation of which is triggered by hypoxia, cytokines, and growth factors and is also induced by activation of the adenosine 2B receptor. VEGF is neuroprotective in several models of experimental brain injury and is increased in brain after traumatic brain injury (TBI) in humans and experimental animals. Adenosine is a neuroprotective purine metabolite that increases in cerebrospinal fluid (CSF) after clinical TBI in children. We hypothesized that VEGF levels would 1). be increased in CSF after TBI in infants and children, and 2). be preceded by increases in CSF adenosine. To test this hypothesis, we designed a case-control study to compare the CSF of infants and children after severe TBI with that of uninjured children. METHODS: Using an Institutional Review Board-approved protocol, we compared CSF concentrations of VEGF (by enzyme-linked immunosorbent assay) and adenosine (by high-performance liquid chromatography) in 73 samples from 14 infants and children with severe TBI (Glasgow Coma Scale score 相似文献