Synthesis of some 2(3H)-benzoxazolone derivatives and their in-vitro effects on human leukocyte myeloperoxidase activity

Myeloperoxidase (MPO), a heme protein expressed by polymorphonuclear leukocytes, generates potent oxidants which are proposed to contribute to tissue damage during inflammation and certain pathogenesis such as neurodegenerative disorders. In this study, twenty omega-[2-oxo-3H-benzoxazol-3-yl]-N-phenylacetamide and propionamide derivatives having substituents of different lipophilic and electronic nature on the N-phenyl ring were synthesized to evaluate the inhibitory effects on in vitro leukocyte MPO chlorinating activity. The most active compounds in the series were the derivatives bearing 2-methyl and 4-nitro substituent on the N-phenyl ring.     

Fucoidin, a neutrophil rolling inhibitor, reduces damage in a rat electrical burn injury model

Background

Electrical injuries induce progressive tissue loss caused by free oxygen radicals released from neutrophil aggregates. Fucoidin, a potent inhibitor of L-selectin function, reduces the aggregation of neutrophils. The aim of this study was to evaluate the effect of fucoidin on tissue damage in rat electrical burn injury model.

Methods

Forty-two male Wistar albino rats (250–300 g) were divided into 3 groups (Group A (n = 6), control group without electrical burn injury; Groups B (n = 18) and C (n = 18), electrical burn injury groups without and with fucoidin therapy, respectively). Three separate analyses were performed at different time points on 6 out of 18 mice from Group B and C at each time point. Biochemistry (myeloperoxidase and malondialdehyde levels) and histopathology (number of neutrophils) of the skin and muscle biopsies at 1st hour; tissue edema (ratio of wet weight/dry weight of extremities) at 24th hour; and necrotic areas at 7th day after electrical injury were evaluated. The electrical burn was induced by exposing rats to 220 V AC between their left upper extremity and right lower extremity for 10 s. Fucoidin was administered as 25 mg/kg intravenous bolus injection at 15 min after electrical burn injury.

Results

Myeloperoxidase and malondialdehyde levels, number of neutrophils, tissue edema, and necrotic area were significantly less in fucoidin-applied rats than the group without fucoidin therapy.

Conclusions

Fucoidin inhibits tissue damage induced by electrical burn injury in rats by reducing necrotic area, edema and number of neutrophils.     

Modified HDL: biological and physiopathological consequences

Epidemiological and clinical studies have demonstrated the inverse association between HDL cholesterol levels (HDL-C) and the risk of coronary heart disease (CHD). This correlation is believed to relate to the ability of HDL to promote reverse cholesterol transport. Remodeling of HDL due to chemical/physical modifications can dramatically affect its functions, leading to dysfunctional HDL that could promote atherogenesis. HDL modification can be achieved by different means: (i) non-enzymatic modifications, owing to the presence of free metal ions in the atherosclerotic plaques; (ii) cell-associated enzymes, which can degrade the apoproteins without significant changes in the lipid moiety, or can alternatively induce apoprotein cross-linking and lipid oxidation; (iii) association with acute phase proteins, whose circulating levels are significantly increased during inflammation which may modify HDL structure and functions; and (iv) metabolic modifications, such as glycation that occurs under hyperglycaemic conditions. Available data suggest that HDL can easily be modified losing their anti-atherogenic activities. These observation results mainly from in vitro studies, while few in vivo data, are available. Furthermore the in vivo mechanisms involved in HDL modification are ill understood. A better knowledge of these pathways may provide possible therapeutic target aimed at reducing HDL modification.     

Serum myeloperoxidase level predicts reperfusion in patients with myocardial infarction receiving thrombolytic therapy

Polymorphonuclear leukocytes play a central role in all stages of the atherothrombotic inflammatory process. The atherothrombotic activity of polymorphonuclear leukocytes is exerted by mediators such as myeloperoxidase (MPO). Although the role of MPO has been studied with respect to the development of adverse cardiac events in acute coronary syndromes (ACS), the association of this molecule with effectiveness of reperfusion in patients receiving thrombolysis is not yet known. The study population consisted of a total of 158 patients with acute coronary syndromes. Final diagnosis was ST-segment elevation myocardial infarction in 86 patients, 80 of whom received thrombolysis. Blood samples were drawn at presentation of the patients and serum myeloperoxidase levels were measured. Reperfusion was defined in terms of electrocardiographic ST-segment resolution. The serum levels of MPO were found to be correlated with rates of in-hospital adverse events including death (P < 0.001), reinfarction (P < 0.001), recurrent ischemia (P < 0.001), arrhythmias (P < 0.001), clinical heart failure (P < 0.001), and cardiogenic shock (P < 0.001). There was a significant difference in serum MPO levels between subjects with three-vessel disease and two- or one-vessel disease (P < 0.001). Pre-lytic serum high-sensitivity C-reactive protein levels in patients with successful reperfusion were lower than in patients with failed reperfusion (P < 0.001). Analysis of patients with ST segment elevation myocardial infarction receiving thrombolytic therapy revealed that pre-lytic serum MPO levels in patients with successful reperfusion were significantly lower than those of patients with failed reperfusion (P < 0.001). In the present study, serum MPO levels were found to be a strong predictor of response to thrombolytic treatment in patients with ST-segment elevation myocardial infarction. Therefore the level of inflammatory activity in acute coronary syndromes seems to influence the effectiveness of fibrinolysis.     

急性冠脉综合征PCI术后血清sCD40L,MPO水平的变化以及阿托伐他汀对二者的影响

目的:探讨ACS患者PCI术后血小板CD40L表达及血浆MPO水平的变化以及阿托伐他汀对二者的影响.方法:126例急性冠脉综合征患者随机分40 mg治疗组、20 mg对照组,分别于术前、术后第1天、7天、1个月空腹检测血清中MPO和sCD40L的水平.结果:(1)ACS发生后血液中sCD40L、MPO会迅速升高,在PCI的影响下,两者继续升高,然后逐渐下降.(2)治疗组PCI术后血清sCD40L、MPO水平的水平明显低于对照组,有统计学差异(P＜0.05).(2).sCD40L与MPO的变化趋势的相关性分析无相关性(P=0.58,r=0.153),结论:PCI术后患者血清炎性因子sCD40L、MPO进一步升高;阿托伐他汀对ACS患者PCI后血清sCD40L、MPO有明显的抑制作用.     

脓毒症小鼠心肌P-选择素基因的表达及意义

目的:探讨脓毒症时小鼠心肌P-选择素表达的改变及其意义.方法:雌性昆明小鼠72只,随机分为对照组(12只)、假手术组(12只)、盲肠结扎穿孔(CLP)组(48只),CLP法制备脓毒症模型,CLP后2、4、8和12 h处死动物分别留取血和心脏组织,采用双抗夹心酶联免疫法(ELISA)检测血清肌钙蛋白Ⅰ(cTnI),测心肌组织髓过氧化物酶(MPO)活性,采用实时荧光定量逆转录多聚酶链反应(RT-PCR)法检测心肌组织P-选择素mRNA表达.结果:CLP组2、4、8和12 h心肌组织P-选择素mRNA表达进行性升高,与对照组和假手术组相比,差异有统计学意义(P＜0.05).而且CLP后心肌组织p-选择素mRNA表达水平与心肌组织MPO活性及血清肌钙蛋白Ⅰ浓度均呈显著正相关.结论:脓毒症时小鼠心肌损伤时,心肌组织P-选择素表达显著升高,可能与心肌组织中性粒细胞浸润及心肌损伤密切相关.     

Alterations in plasma lecithin:cholesterol acyltransferase and myeloperoxidase in acute myocardial infarction: Implications for cardiac outcome

Background

The cholesterol esterifying enzyme, lecithin:cholesterol acyltransferase (LCAT), plays a key role in HDL maturation and remodeling. Myeloperoxidase (MPO) may compromise LCAT enzymatic activity. We tested the extent to which plasma LCAT activity is altered in acute myocardial infarction (MI) in conjunction with abnormal MPO levels. We also assessed the impact of LCAT and MPO on newly developed major adverse cardiovascular events (MACE).

Methods

Two-hundred one consecutive patients referred for acute chest pain of whom 134 had MI (95 with ST-elevation) participated. Forty-five new MACE were ascertained during 1203 (range 13–1745) days of follow-up among 185 patients. Plasma LCAT activity was measured using an exogenous substrate assay. MPO mass was assayed by chemiluminescent microparticle immunoassay.

Results

Plasma LCAT activity was decreased by 15%, coinciding with 7-fold increased MPO levels in acute MI patients vs. patients with non-cardiac chest pain (p < 0.001 for both; correlation: r = −0.343, p < 0.001). MI at admission was associated independently with both lower plasma LCAT activity and higher MPO (age- and sex-adjusted odds ratio per 1 SD increment: 0.46 (95% CI, 0.31–0.68), p < 0.001 and 7.58 (95% CI, 3.34–17.11), p < 0.001, respectively). In an analysis with LCAT and MPO together these associations were modestly attenuated. MPO mass (hazard ratio: 1.59 (95% CI, 1.15–2.19), p = 0.004), but not LCAT activity (hazard ratio: 0.87 (95% CI, 0.65–1.19), p = 0.39), predicted newly manifest MACE.

Conclusion

In acute MI patients, plasma LCAT activity is decreased coinciding with increased MPO levels. Higher MPO but not lower LCAT activity prospectively predicts adverse cardiac outcome.     

羟乙基淀粉对大鼠心肌缺血再灌注后无复流的影响

 目的: 探讨羟乙基淀粉(HES 130/0.4)对大鼠心肌缺血再灌注中无复流现象的影响及机制。方法: 36只SD大鼠随机分为缺血-再灌注组(IR组),生理盐水组(NS-IR组),羟乙基淀粉组(HES-IR组)和假手术组(sham组)。NS-IR和HES-IR组在缺血30 min时分别静注生理盐水和HES 130/0.4,再灌注180 min后以Evans blue、Thilflavin S和TTC染色测定心肌梗死面积与无复流范围,同时检测心肌肌酸激酶同工酶(CK-MB)、心肌肌钙蛋白I(cTnI)含量和髓过氧化物酶(MPO)活性。培养心肌微血管内皮细胞,随机分为正常对照组(Con组),缺氧-复氧组(H/R组),生理盐水组(NS-H/R组)和羟乙基淀粉组(HES-H/R组),以缺氧复氧法模拟急性缺血再灌注,测定游离钙离子浓度、细胞活力和凋亡率。结果: HES-IR组大鼠心肌梗死面积、无复流范围、心肌酶CK-MB、cTnI和MPO与IR组相比均减少(P<0.05)。HES-H/R组细胞内游离钙离子浓度和细胞凋亡率较H/R组亦明显减少(P<0.05),而细胞活力增高(P<0.05)。结论: HES 130/0.4能改善心肌缺血-再灌注后的无复流现象,其机制不仅涉及对中性粒细胞激活、浸润的抑制,还与减轻内皮细胞钙超载有关。     

Effects of sildenafil on inflammatory injury of the lung in sodium taurocholate-induced severe acute pancreatitis rats

BackgroundInflammatory response and acute lung injury (ALI) occur in sodium taurocholate-induced severe acute pancreatitis (SAP). Because sildenafil has anti-inflammatory, anti-oxidant and immune-modulating effects, we investigated its effect on inflammatory and lung injury in sodium taurocholate-induced SAP-associated ALI rat lung.MethodsSodium taurocholate-induced SAP rats received sildenafil (100 mg/kg) or not and were compared to age-matched normal control animals. We evaluated inflammatory response by detecting the expression of inflammatory factors including IL-1β, IL-6 and TNF-α, and detected the level of lung injury through histopathological evaluation. Moreover, we also tested the protein expression of PCNA, P21, Bcl-2 and Bax in the lung.ResultsSildenafil administration rats had a low level of lung injury and inflammation. In addition, sildenafil significantly increased the expression of proliferation-related markers and decreased the expression of apoptosis-related markers in lung tissue.ConclusionsSildenafil administration may attenuate inflammation and lung injury by promoting proliferation and suppressing apoptosis in SAP rats.