糖基化终极产物对心血管系统的损伤作用及干预措施

目的糖基化终极产物(AGEs)是体内蛋白质与糖在无酶条件下发生反应后的产物.正常人体内AGE水平随年龄增长而缓慢增加,疾病状态下,如糖尿病时循环和组织中AGE修饰蛋白水平明显增加.AGEs主要通过与其受体RAGE相互作用介导一系列病理反应,研究表明AGEs可以通过损伤内皮功能、促进平滑肌细胞增殖、诱导心肌细胞凋亡、促进胶原蛋白交联、促进炎症因子及生长因子表达、干扰脂质代谢、影响凝血状态等机制对心血管系统产生损伤,阻滞AGEs/RAGE是心血管疾病治疗的新的靶点.     

高级糖基化终末产物的检测及其临床意义

高级糖基化终末产物(AGEs)是蛋白质、脂类、核酸等生物大分子物质发生非酶糖基化反应的产物。近期大量研究证明，AGEs在糖尿病并发症^[1]、尿毒症^[2]、阿尔次海默病^[3]、白内障^[4]、脊髓侧索硬化症^[5]等疾病和衰老的发生发展过程中具有重要作用，因此检测血清和组织中AGEs的浓度对多种疾病的诊断、治疗及     

酶联免疫吸附实验检测麻疹IgM抗体实验室工作体会

目的探讨麻疹IgM抗体检测过程中的影响因素,在消灭麻疹病毒方面进行有效积极的监测工作,对疑似、确诊的麻疹病例开展准确、及时的疾病监测。方法对疑似、确诊的麻疹病例进行血液采集,分离血清,使用酶联免疫吸附法进行麻疹IgM抗体检测。结果酶联免疫吸附实验中,从试剂盒的选择开始直至最后的结果观察,都存在主观或客观的影响。结论定期使用质控血清,进行实验室内部质量控制,通过制作质控图以及不断地进行人员培训,能有效地避免一些客观因素的影响。     

单克隆多克隆抗体酶联免疫吸附法测定血清脂蛋白(a)的比较

应用淋巴细胞杂交瘤技术，建立了抗人血清脂蛋白（ａ）杂交瘤细胞株，对制备的单克隆抗体进行了特异性鉴定和抗原位点测定。建立了多克隆双抗体夹心酶联免疫吸附法、载蛋白（ａ）、载脂蛋白Ｂ双位点酶联免疫吸附法、单克隆单株、混合株双抗体夹心酶联免疫吸附法对脂蛋白（ａ）进行了检测，并对结果进行了分析。认为样本、参考品间载脂蛋白（ａ）的多态型不同可引起结果间的差异。     

酶联免疫吸附试验(ELISA)检测恶性疟的抗体反应

作者等在萨尔瓦多对从厚血片中查见恶性疟原虫的827例患者的血样进行了ELISA检测。其中仅发现滋养体者403例,查见配子体但有或无滋养体的424例,同时有间日疟感染的63例(7,6%)。另以美国东南部的50名成年居民血样作为阴性对照。除用培养的恶性疟原虫西非Ⅰ株代替巴拿马Ⅱ株以     

血清中可溶性晚期糖基化终末产物受体(sRAGE)与肺癌的相关性分析

目的分析血清中可溶性晚期糖基化终末产物受体(sRAGE)与肺癌的相关性。方法将辽宁省人民医院2015年5月-2018年12月收治的102例肺癌患者纳入本研究,另将同期到我院体检的100例健康体检者作为对照组,应用酶联免疫吸附法(ELISA)测定两组血清sRAGE水平,分析肺癌患者与健康对照者血清sRAGE水平差异及血清sRAGE水平与肺癌患者临床病理特征的相关性,并采用受试者工作特征曲线(ROC)评价血清sRAGE在肺癌中的诊断效能。结果 ELISA检测结果显示,肺癌组血清sRAGE水平[(632.56±203.14)ng/L]明显低于健康对照组[(976.02±283.57)ng/L],二者相比差异具有统计学意义(t=9.879,P0.05)。血清sRAGE水平与肺癌患者的分化程度、TNM分期、淋巴转移及远端转移密切相关(P0.05),而与患者的性别、年龄、肿瘤直径及病理分型无明显关系(P0.05)。采用ROC曲线评价血清sRAGE对肺癌的诊断效能,结果显示,ROC曲线下面积为0.851(95%CI:0.620-0.982),筛选其最佳截断点:当sRAGE为503.39 ng/L时,敏感性为91.39%,特异性为81.42%。结论 sRAGE在肺癌患者血清中表达下调,血清sRAGE水平与肺癌患者的分化程度、TNM分期、淋巴转移及远端转移密切相关,血清sRAGE对肺癌的诊断敏感性和特异性较高,提示sRAGE可能与肺癌的发生及恶性程度有关,检测血清sRAGE可能对肺癌早期诊断有一定价值。     

血浆中糖基化终级产物水平的升高与糖尿病周围大血管并发症的关系

目的:探讨糖基化终级产物(AGEs)与糖尿病周围大血管并发症的相关性.方法:本实验收集了2型糖尿病有周围大血管并发症组(A组)36例病人血浆,2型糖尿病无周围大血管并发症组(B组)46例病人血浆,正常对照组49例.采用竞争性酶联免疫吸附法分析血浆AGEs浓度.结果:在A组中,AGEs浓度[(7.14±1.47)U/ml]明显高于B组[(6.00±2.27)U/ml,P＜0.05],也明显高于正常对照组[(5.39±1.21)U/ml,P＜0.001].以有无并发症为应变量进行多元Logistic回归分析显示,在调整年龄、性别及其它血管危险因素后,血浆AGEs浓度＞6.085 U/ml者,糖尿病并发症发生的危险性增加(风险比值为4.93,95%可信限为1.734～14.079).结论:检验结果显示,血浆AGEs浓度的增加可能是糖尿病周围大血管并发症发生的危险因素.     

用酶联免疫吸附试验(ELISA)检测抗脱氧核糖核酸(DNA)的抗体

作者首先用ELISA比较小牛胸腺的天然DNA和热变性的DNA,以pH5.0的醋酸铵缓冲液稀释至30μg/ml包被聚乙烯微量滴定板的凹井,分别测定4周龄的NIH(GP)小鼠血清(为阴性对照血清)。用甲基化牛血清白蛋白结合DNA的复合物免疫的NIH小鼠血清(琼脂双扩散证明为阳性,作为阳性对照血清)和感染曼氏血吸虫8、9或13周的病鼠血清,结果表明,天然的DNA较     

酶联免疫吸附试验(ELISA)检测血吸虫病患者的IgM及IgE抗体

最近证明在ELISA试验中联合使用血吸虫尾蚴和成虫抗原可以从血清学上区别急性或慢性血吸虫病患者。急性感染患者血清中对尾蚴抗原的IgG抗体多于成虫抗原,而在慢性感染患者则相反。IgM抗体的产生是宿主对许多急性感染反应的特征,蠕虫感染免疫反应的特征是IgE抗体的产生,因之作者探索ELISA试验对检测确诊为急性或慢性血吸虫病患者的特异性IgM及IgE抗体的用途,并对这些抗体水平和尾蚴/成虫     

纤维蛋白(原)降解产物检测在血栓性疾病中的研究

【】目的：探讨纤维蛋白(原)降解产物(FDP)检测在血栓性疾病中的研究。方法：选取2015年4月~2017年2月我院收治的急性脑梗死(ACI)患者82例、深静脉血栓(DVT)患者59例、急性心肌梗死(AMI)76例,分别设为ACI组、DVT组、AMI组,分别于治疗前和溶栓治疗后采用胶体免疫比浊法定量检测血浆FDP含量,另选取同期健康志愿者64名为对照组,评价FDP在血栓性疾病诊断的效能。结果：溶栓治疗前,ACI组、DVT组、AMI组血浆FDP含量及阳性率均明显高于对照组(P＜0.05);血浆FDP对DVT的诊断效能最高,其灵敏性、特异性、阳性预测值、阴性预测值分别为83.05%、100.00%、100.00%、86.49%;溶栓治疗2h后,ACI组、DVT组、AMI组有效亚组患者血浆FDP含量均明显高于无效亚组,而在溶栓治疗24h、48h后,有效亚组患者在溶栓治疗24h、48h后血浆FDP含量均明显低于治疗无效亚组(P＜0.05)。结论：血浆FDP含量测定对ACI、DVT、AMI等血栓性疾病的早期诊断具有一定的作用,溶栓治疗期间监测血浆FDP含量有助于评估溶栓效果。     

Differential expression of receptors for advanced glycation end products on monocytes in patients with IDDM

Summary Accelerated modification of proteins by glucose terminating in the formation of advanced glycation endproducts (AGEs) is one of the main pathogenetic mechanisms of diabetes-associated complications. One pathway by which AGEs may exert their effects is by interaction with specific receptors initially identified on macrophages, monocytes and endothelial cells. As AGE-induced autocrine upregulation of AGE receptors has been observed in vitro, we hypothesized that AGE-binding might be enhanced in diabetic patients to compensate for the elevated levels of circulating AGEs. We therefore examined the expression of AGE-binding sites on peripheral monocytes, serum levels of AGEs and AGE-induced cytokine production in patients with insulin-dependent diabetes mellitus (IDDM) compared to age-matched, healthy control subjects. In patients, AGE-binding capacity was significantly increased and there was only one class of binding sites, as revealed by Scatchard analysis (1.8 × 10⁵ vs 1.4 × 10⁵ binding sites per cell). Affinity of binding was, however, similar (K_a 1.5 × 10⁶ vs 1.4 × 10⁶ mol^{− 1}). Saturation of binding was reached at 2.0–3.0 μmol/l with AGE-bovine serum albumin (BSA) as ligand. In contrast, cytometry using fluorescein isothiocyanate-labelled AGE-proteins showed no saturability and reversibility of AGE-binding up to 80 μmol/l, indicating non-specific binding in this concentration range. Again, this non-specific binding was significantly higher in IDDM patients. In addition, we found much higher levels of circulating AGEs in patients as compared to controls and studied possible functional consequences of increased AGE binding in vitro, monocyte stimulation by AGEs triggering cytokine release to a similar extent in patients and controls, i. e. independently of the AGE-binding capacity. Our finding of an enhanced overall AGE-binding capacity of peripheral monocytes in IDDM could be instrumental in limiting the plasma concentration of AGEs, the non-specific binding coming into play after saturation of specific binding sites by higher plasma AGE-levels. Both binding strategies may act in concert as “damage limitation mechanisms” in the development of AGE-dependent diabetic complications. [Diabetologia (1998) 41: 674–680] Received: 30 September 1997 and in revised form: 15 January 1998     

Inhibitors of advanced glycation end products (AGEs): potential utility for the treatment of cardiovascular disease

Accelerated atherosclerosis and microvascular complications are the leading causes of coronary heart disease, stroke, blindness, and end-stage renal failure, which could account for disabilities and high mortality rates in patients with diabetes. Recent clinical studies have substantiated the concept of "hyperglycemic memory" in the pathogenesis of cardiovascular disease (CVD) in diabetes. Indeed, the Diabetes Control and Complications Trial-Epidemiology of Diabetes Interventions and Complications (DCCT-EDIC) Research, has revealed that intensive therapy during the DCCT reduces the risk of cardiovascular events by about 50% in type 1 diabetic patients 11 years after the end of the trial. Among various biochemical pathways activated under diabetic conditions, the process of formation and accumulation of advanced glycation end products (AGEs) and their mode of action are most compatible with the theory "hyperglycemic memory." Further, there is a growing body of evidence that AGEs play an important role in CVD in diabetes. These observations suggest that the inhibition of AGEs formation may be a promising target for therapeutic intervention in diabetic vascular complications. Therefore, in this article, we review several agents with inhibitory effects on AGEs formation and their therapeutic implications in CVD in diabetes.     

Formation of plasma advanced glycosylation end products (AGEs) has no influence on plasma viscosity

Plasma viscosity is mainly determined by large non-spherical proteins. In Type 1 diabetes mellitus, plasma viscosity increases with deterioration of diabetic control. Since protein glycation and formation of advanced glycosylation end products (AGEs) alter the structural and functional properties of proteins, AGEs might influence the rheological properties of plasma proteins. Therefore, we investigated the influence of plasma-AGEs on plasma viscosity in 34 normoalbuminuric diabetic patients (17 Type 1, 17 Type 2) with normal renal and liver function. In an additional experiment, 6 ml plasma of 9 healthy volunteers were incubated under sterile conditions for 14 days at 37.5 °C in the presence of 5.2 and 32.9 mmol l⁻¹ glucose. In diabetic patients, plasma-AGE levels were not correlated with plasma viscosity. Plasma-AGE levels in healthy controls (246 ± 37 U ml⁻¹, mean ± SD) were raised significantly (p<0.001) after the incubation at 37.5 °C (392 ± 57 U ml⁻¹ and 552 ± 58 U ml⁻¹, respectively). However, no difference was found in plasma viscosity pre- and post-incubation (pre-incubation: 1.25 ± 0.04 mPas, post-incubation: 1.23 ± 0.03 and 1.24 ± 0.03, respectively). We conclude that there is no influence of plasma-AGEs on plasma viscosity. © 1997 John Wiley & Sons, Ltd.     

非酶糖化蛋白对体外培养血管内皮细胞生长的影响

目的 观察糖代蛋白终末产物（ＡＧＥｓ）及高糖对体外培养人血管内皮细胞增殖的影响。方法 采用＾３Ｈ标记的腺嘧啶（＾３－ＴｄＲ）掺入法测定细胞增殖情况。结果 在含ＡＧＥｓ的培养液（５μｇ／ｍｌ）中增培养的新生儿脐带静脉内皮细胞,其２小时＾３Ｈ－ＴｄＲ掺入对照组的２．９５倍（Ｐ〈０．０１）,而在含３０ｍｍｏｌ／Ｌ葡萄糖的２液中培养的人胚胎脐带静脉内皮细胞,其２小时＾３Ｈ－ＴｄＲ掺入对照组（１１ｍｍｏｌ／     

Hepatic disposal of advanced glycation end products during maturation and aging

Aging is characterized by progressive loss of metabolic and biochemical functions and accumulation of metabolic by-products, including advanced glycation end products (AGEs), which are observed in several pathological conditions. A number of waste macromolecules, including AGEs are taken up from the circulation by endocytosis mainly into liver sinusoidal endothelial cells (LSECs) and Kupffer cells (KCs). However, AGEs still accumulate in different tissues with aging, despite the presence of this clearance mechanism. The aim of the present study was to determine whether the efficiency of LSECs and KCs for disposal of AGEs changes through aging.     

Elevation of soluble form of receptor for advanced glycation end products (sRAGE) in diabetic subjects with coronary artery disease

BACKGROUND: Advanced glycation end products (AGEs)-receptor (RAGE) axis is implicated in diabetic vascular complication. Since a soluble form of RAGE (sRAGE) could be generated from the cleavage of cell surface RAGE in endothelial cells (ECs), serum sRAGE levels may be elevated in diabetes consequent to EC damage. In this study, we examined whether sRAGE levels were elevated in type 2 diabetic patients compared with non-diabetic healthy subjects. METHODS: Serum sRAGE levels were examined in 75 Japanese type 2 diabetic patients (29 men and 46 women; mean age 66 +/- 11 years) and 75 age- and sex-matched non-diabetic healthy control subjects. We explored the association between sRAGE levels and coronary artery disease (CAD) in diabetic patients. RESULTS: Serum sRAGE levels were significantly higher in diabetic patients than in non-diabetic subjects (965.3 +/- 544.2 vs 415 +/- 150.4 pg/mL, p < 0.001). In the univariate analysis, diastolic blood pressure (inversely), LDL cholesterol, triglycerides, HDL cholesterol, hemoglobin A(1c), and creatinine were significantly associated with sRAGE. After performing multivariate analyses, the presence of diabetes (p < 0.0001) was a sole independent determinant of sRAGE. Furthermore, there was a significant difference in sRAGE levels between diabetic patients with CAD and those without CAD (1680.6 +/- 891.1 vs 855.2 +/- 372.1 pg/mL, p < 0.001). Multiple stepwise regression analysis revealed that sRAGE and creatinine levels were independent determinants of CAD. CONCLUSIONS: The present study demonstrated that serum sRAGE levels were significantly higher in type 2 diabetic patients than in non-diabetic subjects and positively associated with the presence of CAD.     

Scavenger receptors that recognize advanced glycation end products

Scavenger receptors recognize modified low-density lipoproteins (LDLs) such as acetylated LDL and oxidized LDL. Advanced glycation end products (AGE), which are generated through long-term exposure of proteins to glucose, also behave as active ligands for some scavenger receptors, including class A scavenger receptor (SR-A) and class B scavenger receptors such as CD36 and scavenger receptor, class B, type I (SR-BI). SR-BI, the first identified high-density lipoprotein (HDL) receptor, plays key roles in reverse cholesterol transport by promoting selective uptake of cholesteryl esters (CE) in HDL by hepatocytes, and cholesterol efflux of unesterified cholesterol from peripheral cells to HDL. Using Chinese hamster ovary cells overexpressing SR-BI (CHO-SR-BI cells), it was demonstrated that AGE-bovine serum albumin binds to SR-BI and inhibits selective uptake of HDL-CE by CHO-SR-BI cells as well as cholesterol efflux from CHO-SR-BI cells to HDL, suggesting potential roles of AGE in diabetic dyslipidemia and accelerated atherosclerosis in diabetes.     

晚期糖基化终末产物致动脉粥样硬化的机制

晚期糖基化终末产物(advanced glycation end products,AGE)是由还原糖的羰基与游离氨基反应形成的复合物.AGE通过与其受体(RAGE)结合,改变细胞内信号转导、诱导炎症、增强氧化应激;与胶原交联、修饰脂蛋白等损害血管的完整性;这些导致血管内皮细胞功能紊乱,刺激平滑肌细胞迁移增殖,启动及加速糖尿病动脉粥样硬化和血管并发症的发生发展.阻断AGE-RAGE系统对防治糖尿病并发症具有重要意义.     

Role of advanced glycation end products (AGEs) and receptor for AGEs (RAGE) in vascular damage in diabetes

A non-enzymatic reaction between ketones or aldehydes and the amino groups of proteins, lipids and nucleic acids contributes to the aging of macromolecules and to the development and progression of various age-related disorders such as vascular complications of diabetes, Alzheimer's disease, cancer growth and metastasis, insulin resistance and degenerative bone disease. Under hyperglycemic and/or oxidative stress conditions, this process begins with the conversion of reversible Schiff base adducts, and then to more stable, covalently-bound Amadori rearrangement products. Over a course of days to weeks, these early glycation products undergo further reactions and rearrangements to become irreversibly crossed-linked, fluorescent protein derivatives termed advanced glycation end products (AGEs). There is a growing body of evidence that AGE and their receptor RAGE (receptor for AGEs) interaction elicits oxidative stress, inflammatory reactions and thrombosis, thereby being involved in vascular aging and damage. These observations suggest that the AGE-RAGE system is a novel therapeutic target for preventing diabetic vascular complications. In this paper, we review the pathophysiological role of the AGE-RAGE-oxidative stress system and its therapeutic intervention in vascular damage in diabetes. We also discuss here the potential utility of the restriction of food-derived AGEs in diabetic vascular complications.