Attenuation of infarction in cynomolgus monkeys: preconditioning and postconditioning

Ischemic pre- (IPC) and post- (IPOC) conditioning are very protective in laboratory animals, but it has not been possible to measure their anti-infarct potency in human hearts. Non-human primates are genetically closer to humans than other laboratory animals, but until now there have been no studies of IPC or IPOC in any primate species. Accordingly the left anterior descending coronary artery of cynomolgus monkeys was occluded for 90 min and reperfused for 4 h. In control animals, only 44% of the risk zone infarcted indicating cynomolgus myocardium is much more resistant to infarction than that of rabbits or rats. The regression line for the infarct-risk zone plot was very linear (r = 0.99), and intersected the risk zone axis at 0.82 cm³. Even small changes in infarct size could be detected as a shift in this line. Collateral flow in 12 monkeys was 6.6% of flow to normal myocardium and not a covariate of infarct size. IPC with two cycles of 10-min coronary occlusion/10-min reperfusion reduced infarction to near zero indicating that the innate resistance to infarction was not caused by constitutive preconditioning. Wortmannin, an antagonist of phosphatidylinositol 3-kinase (PI3-K), administered just before release of the 90-min coronary occlusion attenuated IPC’s infarct-sparing effect by ~50% suggesting that PI3-K was involved in preconditioning’s protection. IPOC with six cycles of 30-s reperfusion/30-s coronary reocclusion, a very protective protocol in most species, was much less protective than IPC. We conclude that ischemic preconditioning is extremely protective in cynomolgus hearts despite their sparse collateralization but, surprisingly, the protocol of IPOC used in this study offers less protection.     

Cathepsin L is significantly associated with apoptosis and plaque destabilization in human atherosclerosis

ObjectiveHuman atherosclerotic lesions overexpress elastolytic and collagenolytic cathepsins with unclear pathological implications. The aim of this study was to investigate the relationship among expression of cathepsin L, macrophage apoptosis in coronary artery disease (CAD) patients, clinical symptoms and plaque severity of human carotid atheroma.Methods and resultsQuantitative immunohistochemical analysis of human carotid atherosclerotic lesions (n = 49) showed that expression of lysosomal cathepsin L was significantly increased in atherosclerotic plaques with formation of the necrotic core and rupture of the cap. In those plaques, cathepsin L was associated mainly with CD68-positive macrophages, whereas significant lower levels of smooth muscle cell actin were detected. The expression of cathepsin L in these plaques was also correlated with apoptosis and the stress protein ferritin. Plaques from symptomatic patients showed greater increased levels of cathepsin L than those from asymptomatic patients. Human monocyte-derived macrophages from CAD patients (n = 7) showed significantly higher levels of cathepsin L, cellular lipids and apoptosis versus cells from matched healthy donors (n = 7). 7Beta-hydroxycholesterol significantly enhanced cathepsin L in cells from healthy donors but not in cells from CAD patients. Moreover, macrophage apoptosis was significantly correlated with expression of cathepsin L in cell nuclei and membranes.ConclusionThe results suggest that cathepsin L is involved in death of macrophages, necrotic core formation and development of atherosclerotic plaque instability. Macrophage lysosomal cathepsin L and related apoptosis may be potential targets for modulation or imaging of vulnerable plaques in human atherosclerosis.     

Expression of Egr1 and p53 in human carotid plaques and apoptosis induced by 7-oxysterol or p53

Egr-1 and p53 are involved in pathology of both atherosclerosis and cancer. However, it is unknown whether p53 and Egr1 are interactively involved in apoptosis in atherosclerosis. We found that in human carotid plaques, the expression of p53 was inversely correlated with Egr1. In U937 cells, 7β-hydroxycholesterol and 7-ketocholesterol induced production of reactive oxygen species (ROS), transient up-regulation of Egr1 followed by late induction of p53 and apoptosis. Cells with nuclear fragmentation induced by 7-oxysterol or p53 showed increased levels of p53, but decreased levels of Egr1. In conclusion, ROS induced by 7-oxysterols may function as an early initiator of Egr1 expression. The late induced p53 by 7-oxysterols contributes to apoptotic cell death and is linked to the reduction of Egr1 levels, which resembles the differential expression of p53 and Egr1 in human atheroma progression.     

A single (−)-nicotine injection causes change with a time delay in the affinity of striatal D2 receptors for antagonist, but not for agonist, nor in the D2 receptor mRNA levels in the rat substantia nigra

The in vitro and in vivo effects of (−)-nicotine on dopamine D₂ receptors in the rat neostriatum have been studied using biochemical binding, in situ hybridization and immunocytochemistry. A single i.p. injection (1 mg/kg) of (−)-nicotine resulted in a reduction of theK_D value of the D₂ antagonist [³H]raclopride binding sites in rat neostriatal membrane preparations at 12 h without any significant change in theB_max value. This action of (−)-nicotine was counteracted by pretreatment 15 min earlier with the nicotine antagonist mecamylamine (1 mg/kg, i.p.). However, theK_D and theB_max values of the D₂ agonist [³H]NPA binding sites in the rat neostriatal membrane preparations were not significantly affected 0.5–48 h after a single i.p. injection with 1 mg/kg of (−)-nicotine. No significant change in neostriatal D₂ receptor mRNA levels was observed at any time interval after the (−)-nicotine injection. No significant change was observed in tyrosine hydroxylase (TH) immunoreactivity in either the substantia nigra or the neostriatum, nor in nigral TH mRNA levels during the time interval studied (4–24 h posttreatment). Furthermore, addition of low (10 nM) or high (1 μM) concentrations of (−)-nicotine in vitro to rat neostriatal membranes did not alter the characteristics of [³H]raclopride or [³H]NPA binding. These results indicate that a single (−)-nicotine injection can produce a selective and delayed increase in the affinity of D₂ receptors for the antagonist, but not for the agonist without modifying the levels of D₂ receptor mRNA, probably via the activation of central nicotinic receptors.     

Adaptor protein disabled-2 modulates low density lipoprotein receptor synthesis in fibroblasts from patients with autosomal recessive hypercholesterolaemia

Autosomal recessive hypercholesterolaemia (ARH), characterized clinically by severe inherited hypercholesterolaemia, is caused by recessive null mutations in LDLRAP1 (formerly ARH). Immortalized lymphocytes and monocyte-macrophages, and presumably hepatocytes, from ARH patients fail to take up and degrade plasma low density lipoproteins (LDL) because they lack LDLRAP1, a cargo-specific adaptor required for clathrin-mediated endocytosis of the LDL receptor. Surprisingly, LDL-receptor function is normal in ARH patients' skin fibroblasts in culture. Disabled-2 (Dab2) has been implicated previously in clathrin-mediated internalization of LDL-receptor family members, and we show here that Dab2 is highly expressed in skin fibroblasts, but not in lymphocytes. SiRNA-depletion of Dab2 profoundly reduced LDL-receptor activity in ARH fibroblasts as a result of profound reduction in LDL-receptor protein, but not mRNA; heterologous expression of murine Dab2 reversed this effect. In contrast, LDL-receptor protein content was unchanged in Dab-2-depleted control cells. Incorporation of 35S-labelled amino acids into LDL receptor protein revealed a corresponding apparent reduction in accumulation of newly synthesized LDL-receptor protein on depletion of Dab2 in ARH, but not in control, cells. This reduction in LDL-receptor protein in Dab2-depleted ARH cells could not be reversed by treatment of the cells with proteasomal or lysosomal inhibitors. Thus, we propose a novel role for Dab2 in ARH fibroblasts, where it is apparently required to allow normal translation of LDL receptor mRNA.     

乳腺癌肿瘤干细胞标记物CD44~ ESA~ CD24~(-Λow)在非小细胞肺癌组织中的表达及其意义

背景与目的:人体各种组织都存在干细胞,肿瘤组织也存在肿瘤干细胞(tumor stem cell,TSC)。乳腺癌TSC已经被分离出来,其标记物也已被确定,但肺癌的TSC仍未被分离出来。本研究旨在探讨乳腺癌肿瘤干细胞标记物(CD44 ESA CD24-Λow)在非小细胞肺癌(NSCLC)组织中的表达及其意义。方法:应用免疫组织化学法检测77例NSCLC组织中CD44、ESA与CD24的表达,分析其与患者吸烟、肿瘤的大小、癌的组织学类型、组织分化程度、淋巴结转移和预后的关系。结果:77例NSCLC组织中CD44、ESA与CD24的阳性率分别为63.6%、66.2%和7.8%。低分化及未分化组CD44的阳性率明显高于高分化组,高分化组ESA的阳性率明显高于中度分化组和低分化及未分化组;腺癌组ESA的阳性率明显高于鳞癌组(P<0.05)。CD44 ESA CD24-Λow标记的阳性率为36.4%,与患者吸烟、肿瘤的大小、癌的组织学类型、组织分化程度、淋巴结转移和预后无关(P>0.05)。结论:乳腺癌肿瘤干细胞标记物(CD44 ESA CD24-Λow)表达与NSCLC肿瘤的大小、癌的组织学类型、组织分化程度、淋巴结转移和预后等临床病理学指标无关。     

The value of MDCT in diagnosis of splenic artery aneurysms

OBJECTIVE: To evaluate the clinical value of multiple detector computed tomography (MDCT) in the diagnosis and planning the treatment of splenic aneurysms. METHODS: Eight cases with splenic artery aneurysms (SAA) were retrospectively reviewed. Sixty four-slice spiral CT scans were performed. Intravenous contrast material was injected at 4ml/s, and arterial and venous phase images were obtained. Subsequently, arterial phase images were analyzed and made for CT angiography. The diagnosis was made by using axial and reconstructive images. All of the patients were also performed Doppler color echocardiography. RESULTS: All patients showed splenic artery and splenic artery aneurysms clearly with CT arterial phase images. Among them, six patients had splenic artery aneurysms, one had giant splenic artery aneurysms (GSAA) and one had splenic artery pseudoaneurysms. Ultrasound examination only diagnosed six of them. CONCLUSION: MDCT is a noninvasive and valuable method in diagnosis of splenic artery aneurysms and has high value in determination of treatment plan.     

Safety and efficacy of polymer-free paclitaxel-eluting microporous stent in real-world practice: 1-year follow-up of the SERY-I registry

BackgroundPolymer coating on coronary stents induces vascular inflammatory response,reduces re-endothelialization,and affects long-term outcome after percutaneous coronary intervention (PCI).The SERY-1 registry aimed to determine whether a novel polymer-free paclitaxel-eluting microporous Yinyi stent could improve 1-year outcome after index procedure in real-world clinical practice.Methods Clinical and angiographic data and follow-up outcome were collected in 1045 patients who underwent PCI with implantation of ≥1 Yinyi stents between June 2008 and August 2009 at 27 medical centers.The primary endpoint was the cumulative rate of composite major adverse cardiac events (MACE) and the secondary endpoint was the incidence of stent thrombosis at 1 year.Results Overall,1376 lesions were treated successfully with 1713 Yinyi stents,and 1019 (98.7％) patients received dual antiplatelet therapy for at least 12 months.During 1-year follow-up,8 patients (0.78％) had cardiac death,6 (0.58％)suffered non-fatal myocardial infarction,and 46 (4.46％) underwent repeat PCI due to recurrence of angina,resulting in 1-year MACE-free survival of 94.09％.Stent thrombosis occurred in 10 (0.97％) patients,and the rate of Academic Research Consortium (ARC) definite or probable stent thrombosis was 0.78％.Conclusions Polymer-free paclitaxel-eluting microporous Yinyi stent is effective and safe for interventional treatment of coronary artery disease in real-world clinical practice,without recourse to carrier polymer.Potential long-term clinical advantages of this stent deserve further investigation.     

氟尿嘧啶半乳糖化白蛋白微球表面性质的研究

借助漫反射红光谱（ＤＲＩＲ）、Ｘ－射光电子能谱（ＸＰＳ）技术,对自制的氟尿嘧啶半乳糖化白蛋白微球（Ｆｕ－ＧＢＭ）表面的光谱性质进行了研究。解析结果证实：偶联后,Ｆｕ－ＢＭ表层的Ｆｕ被洗脱,Ｆｕ－ＧＢＭ的表面成功地偶联了半乳糖,表面覆盖率为２５．４％。