Activity of a synthetic hexadecasaccharide (SanOrg123781A) in a pig model of arterial thrombosis.

The activity of SanOrg123781A, a new synthetic antithrombotic drug inhibiting both factor Xa and thrombin through antithrombin (AT), was compared to that of unfractionated heparin (UFH) and of the synthetic pentasaccharide (fondaparinux, SP) in an ex vivo arterial thrombosis model in the pig. Six groups of four pigs were administered intravenously with SanOrg123781A (1, 3, 10 and 30 nmol kg(-1)), UFH (30 nmol kg(-1)) or SP (30 nmol kg(-1)). In this arterial model in which platelet thrombus was formed on a thrombogenic surface under a constant high shear rate, UFH and SP had moderate antithrombotic effects while SanOrg123781A exhibited a strong, dose-dependent inhibitory activity on platelet adhesion and platelet thrombus formation. In contrast to UFH, SanOrg123781A did not modify the activated partial thromboplastin time (aPTT) even at 30 nmol kg(-1), but strongly inhibited thrombin generation. At the same dose, despite a lower antithrombotic activity than SanOrg123781A, UFH significantly affected all the coagulation parameters. Taken together, these results show that SanOrg123781A, due to its potent and selective antifactor Xa and antifactor IIa activities is a promising new antithrombotic agent even in arterial setting.     

Effect of SanOrg123781A, a synthetic hexadecasaccharide, on clot-bound thrombin and factor Xa in vitro and in vivo

Summary. Factor (F)Xa and thrombin bound to the clot during its formation contribute to the propensity of thrombi to activate the coagulation system. The aim of this work was to study the inhibition of clot‐bound FXa and clot‐bound thrombin by SanOrg123781A, a synthetic hexadecasaccharide that enhances the inhibition of thrombin and FXa by antithrombin (AT). SanOrg123781A, designed to exhibit low non‐specific binding to proteins other than AT, was compared with heparin. In buffer, heparin and SanOrg123781A inhibited FXa and thrombin at similar concentrations [concentration inhibiting 50% (IC₅₀) of Xa and IIa activity were, respectively: heparin 120 ± 7 and 3 ± 1 ng mL^?1; SanOrg123781A 77 ± 5 and 4 ± 1 ng mL^?1]. In human plasma, the activity of both compounds was reduced, although the activity of heparin was much more affected than that of SanOrg123781A (IC₅₀ values for inhibition of FXa and FIIa activity were, respectively: heparin 100 ± 5 and 800 ± 40 ng mL^?1; SanOrg123781A 10 ± 5 and 30 ± 3 ng mL^?1). We demonstrated, in agreement with our previous results, that the procoagulant activity of the clot is essentially due to clot‐bound FXa and to some extent to clot‐bound thrombin. We showed that heparin and SanOrg123781A were able to inhibit fragment F1+2 generation induced by clot‐bound FXa with IC₅₀ values of 2 ± 0.5 µg mL^?1 and 0.6 ± 0.2 µg mL^?1, respectively. Both compounds also inhibited clot‐bound thrombin activity, the IC₅₀ values of heparin and SanOrg123781A being 1 ± 0.01 µg mL^?1 and 0.1 ± 0.1 µg mL^?1, respectively. Moreover, both heparin and SanOrg123781A significantly inhibited fibrinopeptide A generated by the action of clot‐bound thrombin on fibrinogen but also by free thrombin generated from prothrombin by clot‐bound FXa with IC₅₀ values of 4 ± 0.6 and 1 ± 0.1 µg mL^?1, respectively. As with clot‐bound enzymatic activities, SanOrg123781A was three times more active than heparin in vivo on fibrinogen accretion onto a pre‐existing thrombus and as activators of recombinant tissue‐type plasminogen activator‐induced thrombolysis. In conclusion, due to the specific activities of SanOrg123781A, this compound is much more active than heparin in the presence of plasma proteins, on clot‐bound enzymes and in in vivo models of thrombosis/thrombolysis.     

Nonpeptide factor Xa inhibitors II. Antithrombotic evaluation in a rabbit model of electrically induced carotid artery thrombosis

SK549 (mol. wt. 546 Da) is a synthetic, selective inhibitor of human coagulation factor Xa (fXa) (K(i) = 0.52 nM). This study compared the antithrombotic effects of SK549 and a series of benzamidine isoxazoline fXa inhibitors with aspirin, DuP 714 (a direct thrombin inhibitor), recombinant tick anticoagulant peptide, or heparin in a rabbit model of electrically induced carotid arterial thrombosis. Compounds were infused i.v. continuously from 60 min before electrical stimulation to the end of the experiment. Values of ED(50) (dose that increases the carotid blood flow to 50% of the control) were 0.12 micromol/kg/h for SK549, 0.56 micromol/kg/h for aspirin, 0.14 micromol/kg/h for DuP 714, 0.06 micromol/kg/h for recombinant tick anticoagulant peptide, and >100 U/kg/h for heparin. The EC(50) (plasma concentration that increased blood flow to 50% of the control) for SK549 was 97 nM. Unlike aspirin and heparin, SK549 was efficacious and, at 1.5 micromol/kg/h i.v. (n = 9), maintained carotid blood flow at 87 +/- 6% of control level for greater than 90 min. Unlike heparin, SK549 inhibited ex vivo fXa activity but not ex vivo thrombin activity. There was a highly significant correlation between K(i) (fXa) and ED(50) of a series of fXa inhibitors (r = 0. 85, P <.001). Therefore, these results suggest that SK549 is a novel, potent, and effective antithrombotic agent in a rabbit model of arterial thrombosis. It is likely that SK549 exerts its antithrombotic effect through selective inhibition of fXa. Furthermore, SK549 may be clinically useful for the prevention of arterial thrombosis.     

Estrogen inhibits the response-to-injury in a mouse carotid artery model.

The atheroprotective effects of estrogen are well documented, but the mechanisms responsible for these effects are not well understood. To study the role of physiologic (nanomolar) estrogen levels on the arterial response-to-injury, we applied a mouse carotid artery injury model to ovariectomized C57BL/6J mice. Mice were treated with vehicle (-E2, n = 10) or 17 beta-estradiol (+E2, n = 10) for 7 d, subjected to unilateral carotid injury, and 14 d later contralateral (normal = NL) and injured carotids from -E2 and +E2 animals were pressure fixed, harvested, and analyzed by quantitative morphometry. E2 levels in +E2 mice were consistently in the nanomolar range (2.1-2.5 nM) at days 0, 7, and 14. At 14 d, measures of both intimal and medial area were markedly increased in the -E2 group: (-E2 vs NL, P < 0.05 for both), but were unchanged from normal levels in the +E2 group (+E2 vs NL, P = NS and +E2 vs -E2, P < 0.05 for both). Cellular proliferation, as assessed by bromodeoxyuridine (BrdU) labeling, was significantly increased over NL in the -E2 mice, but this increase was markedly attenuated in the estrogen replacement group (total BrdU positive cells/section: NL = 6.4 +/- 4.5; -E2 = 113 +/- 26, +E2 = 40 +/- 3.7; -E2 vs NL, P < 0.05; +E2 vs NL, P = NS; -E2 vs +E2, P < 0.05). These data (a) demonstrate significant suppression of the mouse carotid response-to-injury by physiologic levels of estrogen replacement; (b) support the utility of this model in the study of the biologic effects of estrogen on the vascular-injury response; and (c) suggest a direct effect of estrogen on vascular smooth muscle cell proliferation in injured vessels.     

Comparing the antiplatelet effect of clopidogrel hydrogensulfate and clopidogrel besylate: a crossover study

Background  

Clopidogrel hydrogensulfate is a thienopyridine acting as an important antiplatelet agent alone or in combination with acetyl salicylic acid to prevent cardiovascular complications. A different clopidogrel salt, clopidogrel besylate, was approved in Germany as a “new drug” in May 2008. Only one study with 46 healthy men compared the plasma concentrations of both clopidogrel formulas. In our crossover study we measured the antiplatelet effect of clopidogrel hydrogensulfate (CHS, clopidogrel bisulfate) and clopidogrel besylate (CB) using two techniques, whole blood impedance aggregometry and flow cytometry in healthy subjects.     

Delivery of TFPI-2 using ultrasound with a microbubble agent (SonoVue) inhibits intimal hyperplasia after balloon injury in a rabbit carotid artery model

Here we report a new, simple and efficient method by using ultrasound and a microbubble agent (SonoVue) for delivering a gene to balloon-injured carotid arteries for restenosis prophylaxis. The tissue factor pathway inhibitor-2 (TFPI-2) has been shown to inhibit the postinjury intimae hyperplasia in atherosclerotic vessels. New Zealand white rabbits were divided into 4 groups with 14 in each, a treatment control for balloon injury, a gene vehicle control, a gene delivery of TFPI-2 without using ultrasound and a gene delivery of TFPI-2 using ultrasound. After four weeks, the injured artery neointimal proliferation was significantly lower in the TFPI-2 group with ultrasound than the control groups (p < 0.01) according to the measurement of the mean luminal diameters by B-mode ultrasonography. The ratio of intimal/media area and the stenosis rate in the gene delivery facilitated by ultrasound were significantly lower than those of the nonultrasound gene delivering method (p < 0.01).     

Erythropoietin induces excessive neointima formation: a study in a rat carotid artery model of vascular injury

A therapeutic strategy that would mitigate the events leading to hyperplasia and facilitate re-endothelialization of an injured artery after balloon angioplasty could be effective for a long-term patency of the artery. It is hypothesized that erythropoietin (EPO), which has both anti-inflammatory and antiapoptotic properties, will prevent hyperplasia, and its ability to proliferate and mobilize endothelial progenitor cells will re-endothelialize the injured artery. To test this hypothesis, EPO (5000 IU/kg) in solution was injected intraperitoneally 6 hours before vascular injury and then on every alternate day for a week or as a single dose (5000 IU/kg) in a sustained release gel formulation 1 week before the vascular injury. Morphometric analysis revealed nearly continuous re-endothelialization of the injured artery in EPO solution-treated animals (90% vs less than 20% in saline control); however, the treatment also caused excessive neointima formation (intima/media ratio, 2.10 +/- 0.09 vs 1.60 +/- 0.02 saline control, n = 5, P < .001). The EPO gel also induced similar excessive neointima formation. Immunohistochemical analysis of the injured arteries from the animals treated with EPO solution demonstrated a significant angiogenic response in adventitia and media, thus explaining the formation of excessive neointima. Although the results are in contrast to expectation, they explain a greater degree of stenosis seen in hemodialysis access fistulas in patients who are on EPO therapy for anemic condition. The results also caution the use of EPO, particularly in patients who are at a risk of vascular injury or are suffering from an atherosclerotic condition.     

Effect of mechanical ventilation on carotid artery thrombosis induced by photochemical injury in mice

Summary. Background: Increasing use of transgenic and gene targeting techniques for the investigation of hemostasis and vascular biology has generated interest in experimental models of carotid artery thrombosis in mice. Objectives: We tested the hypothesis that hypoventilation in anesthetized mice may cause hypercapnia, increased carotid artery blood flow, and altered thrombotic responses to photochemical injury of the carotid artery. Methods: Arterial blood gases and carotid artery blood flow were measured in pentobarbital‐anesthetized BALB/c or C57BL/6 J mice with and without mechanical ventilation. Photochemical injury of the carotid artery was induced using the rose bengal method. Results: Compared with ventilated mice, unventilated mice had a 45% increase in carotid artery blood flow (0.74 ± 0.04 vs. 0.41 ± 0.03 mL min^?1; P < 0.001) that was associated with an elevation of arterial PCO₂ (58 ± 4 vs. 33 ± 4 mmHg; P < 0.05) and a decrease in arterial pH (7.18 ± 0.05 vs. 7.32 ± 0.03; P < 0.05). Time to first occlusion of the carotid artery after photochemical injury was shorter in ventilated than in unventilated mice (29 ± 6 vs. 73 ± 9 min; P < 0.001). Time to stable occlusion was also shorter in ventilated mice (49 ± 8 vs. 81 ± 6 min; P < 0.05). Elevated carotid artery blood flow, hypercarbic acidosis, and prolonged occlusion times also were observed in mice ventilated with supplemental carbon dioxide. Conclusions: General anesthesia without mechanical ventilation has the potential to confound studies of experimental thrombosis in vivo by producing hypoventilation, hypercapnia, acidosis, and altered carotid artery blood flow. Mechanical ventilation with maintenance of normal blood gases may enhance the physiological insight gained from experimental models of carotid artery thrombosis in mice.     

Delayed pseudoaneurysm formation of the carotid artery following the oral cavity injury in a child: A case report

BACKGROUNDAn impalement injury of the oral cavity is a common traumatic injury in children. In most cases, it is not accompanied by sequelae, but if foreign body residues are not found due to a minor injury, they may result in inflammatory responses and delayed vascular injuries in the surrounding tissues. Without early diagnosis and appropriate initial management, residual foreign bodies can cause serious complications and even mortality in some cases. CASE SUMMARYA 9-year-old boy suffered an intra-oral injury by a wooden chopstick, and the patient was discharged from the hospital after receiving conservative treatment for the injury. However, the patient was readmitted to the hospital due to intra-oral bleeding, and since neck hematoma and right internal carotid artery pseudoaneurysm formation were detected on computed tomography, emergency surgery was performed. A remnant fragment of a wooden chopstick was found during the operation, and a delayed rupture of the internal carotid artery caused by the foreign body was also found.CONCLUSIONThe failure of early detection and diagnosis of a residual foreign body may result in delayed vascular rupture.     

Inhibition of inflammatory responses by ambroxol,a mucolytic agent,in a murine model of acute lung injury induced by lipopolysaccharide

Objective The aim of this study is to investigate whether ambroxol inhibits inflammatory responses in a murine model of lipopolysaccharide-induced acute lung injury (ALI).Methods Mice (n=295) were first intratracheally instilled with lipopolysaccharide (LPS) to induce ALI and then received an intraperitoneal (ip) injection of either normal saline (NS), ambroxol (30 or 90 mg/kg per day) or dexamethasone (2.5 or 5 mg/kg per day) for 7 days. Metabolism (n=10, each), lung morphology (n=5, each) and wet-to-dry lung weight ratio (n=10, each) were studied. The levels of tumor necrosis factor (TNF-), interleukin-6 (IL-6) and transforming growth factor (TGF-1) and the protein concentration (n=5 or 7, each) in bronchoalveolar lavage (BAL) were measured.Results Mice with LPS-induced ALI that were treated with ambroxol at a dosage of 90 mg/kg per day significantly gained weight compared to the control and dexamethasone-treated groups. Ambroxol and dexamethasone significantly reduced the lung hemorrhage, edema, exudation, neutrophil infiltration and total lung injury histology score at 24 and 48 h. In addition, ambroxol and dexamethasone significantly attenuated the lung wet-to-dry weight ratio at 24 and 48 h (p<0.05). Compared to the control group, TNF-, IL-6 and TGF-1 levels in the BAL in both ambroxol- and dexamethasone-treated groups were significantly reduced at 24 and 48 h. The protein in BAL, an index of vascular permeability, was also significantly decreased in the ambroxol- and dexamethasone-treated groups (p<0.05).Conclusion Ambroxol inhibited proinflammatory cytokines, reduced lung inflammation and accelerated recovery from LPS-induced ALI.     

大鼠颈动脉球囊损伤局部A20基因转染后内皮细胞再生及血管超微结构的影响

目的:锌脂蛋白A20是核因子κB信号系统活化的产物.研究证实核因子κB的激活是球囊损伤动脉后血管狭窄发生的重要机制之一.实验拟脱察锌指蛋白A20对大鼠颈总动脉球囊损伤局部血管内皮再生和血管超微结构的影响.＃方法:实验于2006-03/2007-06在大连医科大学附属第二医院中心实验室完成.①实验材料:健康雄性SD大鼠42只,体质量350-400g.②分组及实验过程:采用随机数字表法将大鼠分为3组,每组14只.制备A20质粒DNA,建立大鼠颈总动脉球囊损伤模型(假手术组只进行颈动脉结扎,不进行球囊损伤术);对照组:球囊损伤术后局部灌注Lipofectamine 2000 Reagent TE缓冲液:治疗组:球囊损伤术后局部灌注Lipofectamine 2000 Reagent TE缓冲液 pCAGGS-GFP/A20重组质粒.A20质粒DNA在球囊损伤大鼠颈动脉的局部转染.③实验评估:荧光显微镜观察A20在损伤动脉壁的转染效率;伊文思蓝染色法评估损伤后颈动脉内皮再生情况:透射电镜观察血管超微结构改变.实验过程对动物的处理符合动物论理学标准.结果:①球囊损伤术和A20转染治疗后2周,治疗组再内皮化百分比大于对照组(P＜0.05).②假手术组大鼠颈动脉平滑肌细胞电镜下呈典型的"收缩表型";对照组球囊损伤后3d可见合成型细胞及过渡型细胞,7d血管平滑肌细胞表型发生明显改变,呈典型的"合成表型",治疗组术后7 d可见接近收缩型的血管平滑肌细胞.结论:局部转染A20基因可促进损伤血管内皮再生,抑制损伤处血管平滑肌细胞表型转化.     

Potential of carnosine,a histamine precursor in rat model of bilateral common carotid artery occlusion‐induced vascular dementia

The present study investigates the potential of Carnosine, a histamine precursor in rat model of bilateral common carotid artery occlusion (BCCAo)‐induced vascular dementia (VaD). Wistar rats were subjected to BCCAo procedure under anaesthesia to induce VaD. The rats were subjected to Morris water maze (MWM) test (6th day onwards post‐surgery). MWM test was employed to assess learning and memory of the animals whereby escape latency time, time spent in target quadrant and Path length (distance travelled) taken as important parameters. Serum nitrite level; Brain thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) levels; Brain acetylcholinesterase (AChE) activity; brain Myeloperoxidase activity (MPO) and neutrophil count were estimated as per standard procedures. BCCAo in rats produced a significant vascular endothelial dysfunction, as reflected by decrease in serum nitrite levels. Further, these animals showed poor performance on MWM, depicting impairment of learning and memory. There was a significant rise in brain oxidative stress level as indicated by increase in TBARS and decrease in GSH levels. An increase in brain AChE activity was also observed. Moreover, these rats also exhibited an increase in MPO activity and neutrophil infiltration in brain (as marker of inflammation). Treatment of Carnosine (200 and 400 mg/kg, i.p.)/Donepezil (0.3 mg/kg, i.p.) ameliorated BCCAo‐induced memory deficits; endothelial dysfunction; biochemical and histopathological changes. It is concluded that Carnosine has shown efficacy in rat model of BCCAo‐induced VaD and can be considered as an important therapeutic agent for the treatment of VaD.     

Effects of inhaled nitric oxide in a mouse model of sepsis-induced acute lung injury

OBJECTIVE: Although inhaled nitric oxide transiently improves oxygenation in patients with acute lung injury, it has not affected clinical outcomes. As well, the effects of inhaled nitric oxide on the pathophysiologic features of acute lung injury have not been well defined. Therefore, we assessed the effects of inhaled nitric oxide on the degree of pulmonary inflammation and injury in a mouse model of sepsis-induced acute lung injury. DESIGN: Randomized, controlled animal study. SETTING: Research laboratory of an academic institution. SUBJECTS: Male C57Bl/6 mice. INTERVENTIONS: Sepsis was induced by cecal ligation and perforation. At the time of surgery, septic and na?ve mice were randomized to exposure to either 40 ppm inhaled nitric oxide or room air for 24 hrs before they were killed. MEASUREMENTS AND MAIN RESULTS: Sepsis-induced acute lung injury was characterized by increased pulmonary myeloperoxidase (68 +/- 13 vs. 13 +/- 3 mU/mg protein in na?ve mice, p <.01), pulmonary 8-isoprostane content (627 +/- 51 vs. 88 +/- 20 pg/mg protein in na?ve mice, p <.01), and protein in bronchoalveolar lavage fluid (p <.05). Inhaled nitric oxide exposure in septic mice completely abrogated the septic increases in myeloperoxidase activity (p <.05) and pulmonary 8-isoprostane content (p <.05) but had no effect on bronchoalveolar lavage protein. The induction of sepsis also was associated with an increase in pulmonary inducible NO synthase activity (2.8 +/- 0.5 vs. 0.4 +/- 0.1 pmol small middle dotmin-1 small middle dotmg-1 protein in na?ve mice, p <.05), and inhaled nitric oxide attenuated this increase in pulmonary inducible NO synthase activity (p <.05). CONCLUSIONS: Exposure to inhaled nitric oxide early in the course of sepsis-induced acute lung injury is associated with reduced pulmonary leukocyte infiltration and less oxidative injury. Decreased lung inflammation and injury with inhaled nitric oxide is associated with decreased pulmonary inducible NO synthase activity. Therefore, inhaled NO may have greater clinical benefit if administered earlier in the natural history of acute lung injury in patients.     

High-flow venous pouch aneurysm in the rabbit carotid artery: A model for large aneurysms

Background and purpose

Currently one of the most widely used models for the development of endovascular techniques and coiling devices for treatment of aneurysm is the elastase-induced aneurysm model in the rabbit carotid artery. Microsurgical techniques for creating an aneurysm with a venous pouch have also been established, although both techniques usually result in aneurysms less than 1 cm in diameter. We investigated whether an increase in blood flow toward the neck would produce larger aneurysms in a microsurgical venous pouch model.

Materials and methods

Microsurgical operations were performed on 11 New Zealand white rabbits. Both carotid arteries and the right jugular vein were dissected, and the right carotid artery was temporarily clipped followed by an arteriotomy. The left carotid artery was also clipped proximally, ligated distally, and sutured onto the proximal half of the arteriotomy in the right carotid artery. The venous graft was sutured onto the distal half of the arteriotomy. Digital subtraction angiography was also performed.

Results

Angiography showed patent anastomosed vessels and aneurysms in the seven surviving rabbits. Mean aneurysm measurements among surviving rabbits with patent vessels were: 13.9 mm length, 9.3 mm width, and neck diameter 4.7 mm. The resulting mean aspect ratio was 3.35 and the mean bottleneck ratio was 3.05.

Conclusion

A large venous graft and increased blood flow toward the base of the aneurysm seem to be key factors in the creation of large venous pouch aneurysms. These large aneurysms allow testing of endovascular devices designed for large and giant aneurysms.     

Adenosine diphosphate-inducible platelet reactivity shows a pronounced age dependency in the initial phase of antiplatelet therapy with clopidogrel

Summary.  Background:  Until recently, there were hardly any data on the antiplatelet effect of clopidogrel in advanced age. Like other metabolic processes, the conversion of clopidogrel to its active metabolite may be impaired in older patients, leading to high on-treatment residual ADP-inducible platelet reactivity. Objective:  To investigate the age dependency of clopidogrel-mediated platelet inhibition. Patients and methods:  This was a prospective observational study. We determined adenosine 5'-diphosphate (ADP)-inducible platelet reactivity using light transmission aggregometry (LTA) and the VerifyNow P2Y12 assay in 191 patients on dual antiplatelet therapy after angioplasty and stenting for cardiovascular disease. Results:  ADP-inducible platelet reactivity increased linearly with age after adjustment for cardiovascular risk factors, type of intervention, medication, C-reactive protein (CRP) and renal function [using LTA 0.36% of maximal aggregation per year, 95% CI 0.08–0.64%, P  = 0.013; using the VerifyNow P2Y12 assay 3.2 P2Y12 reaction units (PRU) per year, 95% CI 1.98–4.41 PRU, P  < 0.001]. ADP-inducible platelet reactivity was significantly higher in patients aged 75 years or older compared with younger patients ( P  = 0.003 for LTA and P  < 0.001 for the VerifyNow P2Y12 assay). Further, high on-treatment residual ADP-inducible platelet reactivity was significantly more common among patients aged 75 years or older ( P  = 0.02 for LTA and P  < 0.001 for the VerifyNow P2Y12 assay). Conclusion:  ADP-inducible platelet reactivity shows a pronounced age dependency in the initial phase of antiplatelet therapy with clopidogrel. The clinical implications of these findings need to be addressed in future trials.     

颈动脉球囊损伤大鼠白细胞介素6、白细胞介素10及白细胞介素17A mRNA表达:罗格列酮干预的意义

背景:炎症在球囊损伤后血管增生中起重要作用,抑制炎症的发生、发展可以减少血管成形后再狭窄.研究表明PPAR_Y激动剂对抑制炎症发生有一定作用.目的:观察大鼠颈动脉损伤后炎症因子的变化及应用PPAR_Y激动剂罗格列酮干预后的表达变化.设计、时间及地点:随机对照动物实验,于2009-01/06在深圳市人民医院中心实验室完成.材料:SPF级雄性SD大鼠,体质量350 g左右,用于制备颈动脉球囊导管损伤模型.方法:36只SD大鼠随机数字表法分为3组,每组12只.对照组:生理盐水灌胃4 d后行假手术,术后13 d予生理盐水灌胃;球囊损伤组:生理盐水灌胃4 d后行左侧颈总动脉行球囊损伤,术后予生理盐水灌胃13d;罗格列酮组:罗格列酮灌胃4d后行左侧颈总动脉球囊损伤,术后罗格列酮灌胃13d.主要观察指标:术后14d麻醉处死并取左侧颈总动脉,损伤血管行苏木精-伊红染色,观察内膜变化.Real time RT-PCR检测大鼠损伤血管组织中自细胞介素6、白细胞介素10、白细胞介素17A mRNA水平.Western Blot检测大鼠损伤血管组织中核因子kB水平.结果:36只大鼠因造模失败和死亡排除5只,进入结果分析31只.①罗格列酮组白细胞介素6、白细胞介素17A mRNA表达水平明显低于球囊损伤组但高于对照组(P<0.05).罗格列酮组白细胞介素10 mRNA表达高于球囊损伤组和对照组(P<0.05).②罗格列酮组核因子kB水平明显低于球囊损伤组但高于对照组(P<0.05).③球囊损伤后,内膜面积增厚,内膜/中膜比率增长,与对照组相比,差异有显著性意义(P<0.05).罗格列酮治疗后内膜面积及内膜面积/中膜面积较球囊损伤减小但高于对照组(P<0.05).结论:罗格列酮通过核因子kB调节白细胞介素6、白细胞介素10、白细胞介素17A mRNA表达,调节炎症因子的平衡,抑制损伤血管的炎症反应,减轻损伤血管的狭窄.     

Insulin-like growth factor-1 protects from vascular stenosis and accelerates re-endothelialization in a rat model of carotid artery injury

Background:  IGF-1 is a potent mitogen for vascular smooth muscle cells, but exerts protective effects on endothelial cells that may trigger antiatherogenic mechanisms. Objectives:  This study was designed to test the hypothesis that an IGF-1 excess following arterial injury prevents neointima formation and vascular stenosis. Methods:  Rats were subjected to carotid balloon injury and treated with IGF-1 (1.2 mg kg⁻¹ per die) or saline for 10 days. Results:  In IGF-1 treated animals, high tissue levels of eNOS, Akt and its phosphorylated form were found, confirming activation of IGF-1-dependent signaling pathways. IGF-1 markedly reduced neointima formation and post-injury arterial stenosis. IGF-1 exerted proliferative and anti-apoptotic effects in the media of injured carotids, but inhibited mitotic activity and induced apoptosis in the neointima. Furthermore, IGF-1 stimulated mobilization of progenitor endothelial cells and re-endothelialization of the injured arteries. L-NAME administration inhibited IGF-1 vasculoprotective effects. Conclusions:  IGF-1 attenuates post-injury carotid stenosis by exerting differential effects in the neointima and tunica media with regard to the key components of the response to injury. The data point to a novel role of IGF-1 as a potent vasculoprotective factor.     

Bleeding tendency in dual antiplatelet therapy with aspirin/clopidogrel: rescue of the template bleeding time in a single-center prospective study

Background

Patients with heightened platelet reactivity in response to antiplatelet agents are at an increased risk of recurrent ischemic events. However, there is a lack of diagnostic criteria for increased response to combined aspirin/clopidogrel therapy. The challenge is to identify patients at risk of bleeding. This study sought to characterize bleeding tendency in patients treated with aspirin and clopidogrel.

Patients/methods

In a single-center prospective study, 100 patients under long-term aspirin/clopidogrel treatment, the effect of therapy was assayed by template bleeding time (BT) and the inhibition of platelet aggregation (IPA) by light transmission aggregometry (LTA). Arachidonic acid (0.625 mmol/L) and adenosine diphosphate (ADP; 2, 4, and 8 ??mol/L) were used as platelet agonists.

Results

Bleeding episodes (28 nuisance, 2 hematuria [1 severe], 1 severe proctorrhagia, 1 severe epistaxis) were significantly more frequent in patients with longer BT. Template BT ?? 24 min was associated with bleeding episodes (28 of 32). Risk of bleeding increased 17.4% for each 1 min increase in BT. Correlation was found between BT and IPAmax in response to ADP 2 ??mol/L but not to ADP 4 or 8 ??mol/L.

Conclusion

In patients treated with dual aspirin/clopidogrel therapy, nuisance and internal bleeding were significantly associated with template BT and with IPAmax in response to ADP 2 ??mol/L but not in response to ADP 4 ??mol/L or 8 ??mol/L.     

同基因背景小鼠核蛋白诱导狼疮鼠模型

背景：自发性狼疮鼠模型不能对基因以外其他的致病因素进行研究。目的：以同基因背景Balb/c小鼠核蛋白免疫小鼠后诱导狼疮鼠模型。方法：选取4～6周SPF级Balb/c小鼠30只,等分为3组。V1组肌肉注射提取的同系Balb/c小鼠核蛋白,间隔3周免疫1次,共免疫4次;V2组注射等体积PBS;V3组为正常对照。检测小鼠末次免疫后3周的24h尿蛋白、血清抗核抗体、抗双链DNA抗体、小鼠肾脏直接免疫荧光。结果与结论：V1组小鼠24h尿蛋白、血清抗双链DNA抗体、抗核抗体均明显高于V2组、V3组,且V1组小鼠肾小球有免疫球蛋白G免疫复合物沉积,可见肾小球轮廓,V2组、V3组未见肾小球轮廓,只见非特异性的微弱荧光。说明以同基因背景Balb/c小鼠核蛋白免疫Balb/c小鼠能够成功诱导狼疮鼠模型。     

同基因背景小鼠核蛋白诱导狼疮鼠模型

背景:自发性狼疮鼠模型不能对基因以外其他的致病因素进行研究。目的:以同基因背景Balb/c小鼠核蛋白免疫小鼠后诱导狼疮鼠模型。方法:选取4～6周SPF级Balb/c小鼠30只,等分为3组。V1组肌肉注射提取的同系Balb/c小鼠核蛋白,间隔3周免疫1次,共免疫4次;V2组注射等体积PBS;V3组为正常对照。检测小鼠末次免疫后3周的24h尿蛋白、血清抗核抗体、抗双链DNA抗体、小鼠肾脏直接免疫荧光。结果与结论:V1组小鼠24h尿蛋白、血清抗双链DNA抗体、抗核抗体均明显高于V2组、V3组,且V1组小鼠肾小球有免疫球蛋白G免疫复合物沉积,可见肾小球轮廓,V2组、V3组未见肾小球轮廓,只见非特异性的微弱荧光。说明以同基因背景Balb/c小鼠核蛋白免疫Balb/c小鼠能够成功诱导狼疮鼠模型。