定量组织速度成像技术评价阿霉素诱导兔心肌病模型：与常规经胸超声心动图比较

目的:采用定量组织速度成像技术评价阿霉素诱导兔心肌病模型,并与常规经胸超声心动图比较其评估优势。方法:实验于2005-06/2006-08在大连医科大学完成。①实验分组及处理:取纯种新西兰白兔22只,雌雄不限,随机分成阿霉素组12只,给予阿霉素每次2mg/kg,以1g/L耳缘静脉注射,每周1次,注射8周;对照组10只每周注射2mL/kg生理盐水,共8周。②实验评估:每周应用HPSonos5500型彩色多普勒超声诊断仪(美国Agilent公司生产)对两组兔心脏进行左室收缩末期和舒张末期内径明、室间隔厚度、E峰、射血分数、左室短轴缩短率等常规超声参数测量,使用GEVivid7型彩色多普勒超声诊断仪(美国GE公司生产)进行收缩期和舒张期峰值速度、收缩期加速度定量组织速度成像参数测定。结果:22只兔进入统计。①对照组1～12周各参数与阿霉素组基础状态下比较无明显差异(P>0.05)。②第4周阿霉素组二尖瓣环运动的平均收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P均<0.05)。③第7周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),E峰较基础状态明显减低(P<0.05)。④第8周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),E峰较基础状态明显减低(P<0.01),左室收缩末期和舒张末期内径明显增大(P<0.05)。⑤第12周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),左室收缩末期和舒张末期内径明显增大(P<0.01),室间隔厚度、左室后壁厚度明显变薄(P<0.05),射血分数、左室短轴缩短率和E峰明显减低(P<0.01)。结论:定量组织速度成像参数可有效评价阿霉素诱导心肌病模型兔心肌的病理变化,较常规超声参数更敏感。     

两种荧光显微成像系统亚细胞定位的对比

目的:应用高分辨率荧光显微成像系统采集细胞器探针图像,并与激光共聚焦显微成像系统进行对比。方法:实验于2003-05/2004-01在解放军总医院完成。①实验材料:鼠肺毛细血管内皮细胞株(1H11)由上海复旦张江生物公司提供;荧光探针Rhodamine-123,Lucifer Yellow,DiOC6[3],BODIPY(美国Sigma公司)。②细胞培养及荧光探针染色:细胞培养采用含体积分数为0.2胎牛血清的低糖DMEM培养基,密度5×107L-1。选择Rhodamine-123作为细胞线粒体特异性荧光探针,选择DiOC6[3]作为细胞内质网特异性荧光探针,选择BODIPY作为细胞高尔基体特异性荧光探针,选择Lucifer Yellow作为细胞溶酶体探针。前3个探针在完全避光条件下与培养的细胞共同孵育0.5h,后者则共同孵育15h。③高分辨率荧光成像系统的图像采集:线粒体荧光图像采集,选取经Rhodamine-123共孵育完成的细胞,选择激发滤色镜为BP460-490,吸收滤色镜为BA515,分光镜为DM500,另加一绿通道液晶滤光片,激发出Rhodamine-123的荧光。电荷耦合器件采集图像并送入计算机。重复上述步骤,采用DiOC6[3]标记内质网,BODIPY标记高尔基体,Lucifer Yellow标记细胞溶酶体,激发条件同Rhodamine-123。分别采集同一视野靶细胞DiOC6[3]、BODIPY或Lucifer Yellow的荧光图像,完成全部图像采集并储存在计算机中。④激光共聚焦显微成像系统的图像采集:选择经4种探针染色的靶细胞,使用氩离子激光器在488nm激发Rhodamine-123,Rhodamine-123荧光通过配置有530/60-G发射滤光片的通道1探测。重复上述步骤,在488nm激发DiOC6[3]和BODIPY,在457nm激发Lucifer yellow,3种荧光均由通道1探测,后2个探针的发射滤光片的配置为515/30-G,DiOC6[3]选择530/60-G。由光电倍增管接收信号并传输入计算机成像。结果:①高分辨率荧光成像系统所采集图像,靶细胞中由荧光探针Rhodamine-123染色的线粒体呈多个典型的小棒状或卵圆状,聚集在核周;Lucifer yellow染色的溶酶体呈多个非对称球型,在胞浆内随机分布,颗粒尺寸通常大于线粒体;荧光探针DiOC6[3]着色的内质网占据胞浆的很大空间,以囊状聚集为特征;BODIPY特异性地结合在高尔基体上,荧光图像显示围绕在细胞核周围呈条索状。②与高分辨率荧光成像系统比较,激光共聚焦显微成像系统所采集的图像其荧光强度基本相同,但分辨率低、细节显示模糊、胞浆中细胞器的准确分布信息和形态特征显示效果欠佳。结论:两种荧光显微成像系统均可采集到细胞器探针的荧光图像。但高分辨率荧光成像系统采集的荧光图像具有细节清晰、分辨度高、准确显示胞浆中细胞器的分布信息和形态特征等优点。     

卡托普利对大鼠t-PA和PAI-1活性的作用

目的评价卡托普利对大鼠血浆t-PA和PAI-1活性水平的影响。方法给大鼠应用三种剂量的卡托普利,观察其对大鼠血浆t-PA和PAI-1活性水平的作用。结果卡托普利治疗后使大鼠血浆t-PA活性升高,PAI-1活性及PAI-1/t-PA活性比值显著降低,这种作用呈某种程度的剂量依赖性。结论卡托普利能增强大鼠纤溶系统的活性,这种作用呈某种程度的剂量依赖性。     

汉族志愿者阿米替林代谢与异喹呱羟化代谢的关系

8名男性健康志愿者po阿米替林100 mg后,以阿米替林及其3种代谢物的血浓度曲线下面积(AUC₀^∞)计算阿米替林的脱甲基化代谢及羟基化代谢能力。结果提示个体间阿米替林及其3种代谢物的AUC差异很大。其中7名志愿者测定异喹呱羟化代谢表型,6例为异喹呱强代谢者,1例为弱代谢者。尿中异喹呱的羟化代谢率与阿米替林的羟基化代谢率、阿米替林和10-羟基阿米替林的AUC₀^∞呈显著相关。阿米替林总血浆清除率与异喹呱羟化代谢率呈弱相关。此结果表明阿米替林和异喹呱的羟化代谢可能由同一酶控制,阿米替林的羟基化代谢和脱甲基化代谢可能为两个独立的代谢途径。     

Stimulation of bladder activity by volume, L-dopa and capsaicin in normal conscious rats - effects of spinal α1-adrenoceptor blockade

To study possible differences in α₁-adrenoceptor involvement in the spinal mechanisms mediating bladder activity induced by volume (bladder filling), central (L-dopa), and peripheral (capsaicin) stimulation, we investigated if these types of bladder activity were modified by intrathecal (i.t.) or intra-arterial (i.a.) administration of the α₁-adrenoceptor antagonist, indoramin. Indoramin is selective for the α_1A-adrenoceptor subtype, whereas most clinically used α₁-adrenoceptor antagonists, including doxazosin, have no subtype selectivity. The drug effects were studied by continuous cystometry in normal, conscious rats and rats with bladder activity evoked by intraperitoneal L-dopa (50 mg/kg after carbidopa pretreatment), or by intravesical capsaicin (30 μM). I.t. indoramin (50 nmol) significantly decreased micturition pressure, and increased bladder capacity and micturition volume. Dribbling incontinence due to urinary retention was observed in one of ten rats. L-dopa-stimulated bladder overactivity was significantly attenuated by i.t. or i.a. indoramin (50 nmol). Similar effects of i.t. and i.a. doxazosin (50 nmol) have been reported previously. Intravesical capsaicin (30 μM) caused bladder activity, which was attenuated by i.t. indoramin (50 nmol), but not by i.t. doxazosin (50 nmol). I.a. indoramin did not reduce capsaicin-induced bladder activity; doxazosin was moderately effective. The results suggest that the bulbospinal micturition reflex evoked by bladder filling and L-dopa involves a descending pathway where transmission is partly mediated by spinal α₁-adrenoceptors. Bladder overactivity evoked by intravesical capsaicin, which elicits a vesico-spinal-vesical reflex, was not affected by i.t. doxazosin in a dose that attenuates activity mediated through the bulbo-spinal pathway. This suggests less involvement of spinal α₁-adrenoceptors in the vesico-spinal-vesical than in the bulbo-spinal voiding reflex. Received: 29 November 1996 / Accepted: 3 March 1997     

Effects of spinal α1-adrenoceptor antagonism on bladder activity induced by apomorphine in conscious rats with and without bladder outlet obstruction

To test the hypothesis that the spinal control of micturition involves α₁-adrenoceptors, the urodynamic effects of intrathecal and intraarterial α₁-adrenoceptor blockade on apomorphine-induced bladder activity in rats were studied. Continuous cystometry was performed in conscious female Sprague-Dawley rats with and without bladder outflow obstruction. In normal rats, subcutaneous apomorphine, 30 μg/kg, induced bladder activity that was abolished or attenuated by the α₁-adrenoceptor antagonists indoramin and doxazosin given intrathecally or intra-arterially. In rats with outlet obstruction, apomorphine 30 μg/kg caused no change in cystometric parameters. However, at a dose of 100 μg/kg the drug induced bladder activity, which was attenuated by intrathecal indoramin or doxazosin. These results suggest that the bladder activity evoked by apomorphine-stimulation of bulbospinal pathways can be influenced by α₁-adrenoceptors at the spinal and peripheral levels, both in normal rats and in rats with bladder hypertrophy secondary to outlet obstruction. Neurourol. Urodynam. 16:191–200, 1997. © 1997 Wiley-Liss, Inc.     

Expression of Vascular Notch Ligand Delta-Like 4 and Inflammatory Markers in Breast Cancer

Delta-like ligand 4 (Dll4) is a Notch ligand that is predominantly expressed in the endothelium. Evidence from xenografts suggests that inhibiting Dll4 may overcome resistance to antivascular endothelial growth factor therapy. The aims of this study were to characterize the expression of Dll4 in breast cancer and assess whether it is associated with inflammatory markers and prognosis. We examined 296 breast adenocarcinomas and 38 ductal carcinoma in situ tissues that were represented in tissue microarrays. Additional whole sections representing 10 breast adenocarcinomas, 10 normal breast tissues, and 16 angiosarcomas were included. Immunohistochemistry was then performed by using validated antibodies against Dll4, CD68, CD14, Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin (DC-SIGN), CD123, neutrophil elastase, CD31, and carbonic anhydrase 9. Dll4 was selectively expressed by intratumoral endothelial cells in 73% to 100% of breast adenocarcinomas, 18% of in situ ductal carcinomas, and all lactating breast cases, but not normal nonlactating breast. High intensity of endothelial Dll4 expression was a statistically significant adverse prognostic factor in univariate (P = 0.002 and P = 0.01) and multivariate analyses (P = 0.03 and P = 0.04) of overall survival and relapse-free survival, respectively. Among the inflammatory markers, only CD68 and DC-SIGN were significant prognostic factors in univariate (but not multivariate) analyses of overall survival (P = 0.01 and 0.002, respectively). In summary, Dll4 was expressed by endothelium associated with breast cancer cells. In these retrospective subset analyses, endothelial Dll4 expression was a statistically significant multivariate prognostic factor.The growth of tumors requires angiogenesis,¹ which is the consequence of increased expression of proangiogenic factors (for example, vascular endothelial growth factor A [VEGF]^2,3). The expression of VEGF in cancer is controlled by oncogenic signaling,⁴ hypoxia,⁵ and inflammatory cells.⁶ Although there is redundancy among proangiogenic factors in advanced cancer,⁷ many in vivo early stage cancer models show VEGF dependence.^8,9This observation has been exploited clinically, where the addition of an anti-VEGF antibody (bevacizumab) to first line taxane-based chemotherapy in recurrent/metastatic breast cancer was associated with prolongation of progression free survival (from a median of 5.9 to 11.8 months, P < 0.001).¹⁰ Nevertheless, there was no statistically significant overall survival benefit, and all patients in this trial eventually progressed after 4 years.¹⁰ Furthermore, a trial evaluating the addition of bevacizumab to capecitabine in previously treated metastatic/advanced breast cancer demonstrated only a 10.7% improvement in response rate and no survival benefit.¹¹ To date, there are no validated clinical, radiological, or molecular biomarkers that can predict the survival benefit afforded by bevacizumab.^12,13,14,15 Clinical data suggest that antiangiogenic drugs are active in breast cancer,^10,16 and it may be necessary to identify biomarkers that predict their benefit.Additional agents that disrupt functional angiogenesis have been developed to target tumors resistant to anti-VEGF therapy.^17,18 Recent studies have focused on Delta-like ligand 4 (Dll4), a ligand for Notch receptors 1, 3, and 4^17,18,19 that is predominantly expressed by endothelial cells.^17,18,19 Transgenic mice in which Dll4 was replaced by a reporter gene showed that Dll4 expression is restricted to large arteries during development.^20,21 Furthermore, Dll4 heterozygous knockout mice are reported to have defective arterial development²² and venous malformations.²²Experimental systems^17,23,24 have shown that Dll4-Notch inhibition leads to increased sprouting and branching of vessels in association with gradients of VEGF. Conversely, VEGF blockade causes a reduction in Dll4 expression and vessel sprouting.^{17,18,23,24,25,26,27} In addition, endothelial cells transfected with Dll4 down-regulated VEGF receptors KDR and neuropilin1 and showed reduced proliferative and migratory responses to VEGF.²⁸ The implication of this research is that Dll4-Notch signaling regulates endothelial sprouting and branching to form functional vascular beds, under the control of VEGF and by autoregulation of VEGF signaling.²³Disruption of Dll4 signaling by overexpression or inhibition of Dll4 may impair angiogenesis,^17,18 and blockade of Dll4-Notch signaling results in an increased density of nonfunctional vasculature and is associated with a reduction in the growth of human tumor xenografts.^17,18 Indeed, certain xenografts that are resistant to anti-VEGF therapy are reported to be sensitive to anti-Dll4,^17,18,29 and combination treatment with anti-VEGF and anti-Dll4 has additive inhibitory effects on tumor growth.¹⁸ Together these data provide a rationale to target Dll4 in cancer and suggest that Dll4 may have a role in mediating resistance to anti-VEGF therapies.Besides direct vascular effects, Fung et al³⁰ showed that Dll4-Notch signaling in macrophages stimulates a proinflammatory response, which may be proangiogenic.⁶ Moreover, Shojaei et al^31,32 have reported that bevacizumab resistance in certain preclinical in vivo cancer models is causally associated with tumor infiltration by myeloid cells.The characterization of Dll4 protein expression in human cancer is important for the rational design of clinical trials to test the safety and activity of anti-Dll4 therapy. Defining the pattern of Dll4 expression, in association with markers of inflammation, may identify subgroups with distinct clinical behavior and responses to treatment. The aims of this study were to characterize the in situ expression of Dll4 in breast cancer, to assess the association between Dll4 and established markers of inflammation (CD68, CD14, neutrophil elastase, CD123, and Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin [DC-SIGN]) and hypoxia (carbonic anhydrase 9 [CA9]), and to determine the prognostic significance of these markers.