二维超声对正常人不同年龄段足背动脉的观察报告

目的观察正常人足背动脉在不同年龄段的变化。方法将29～75岁的正常检查对象分为不同年龄段的5组,对200支足背动脉进行检查。观察其内径,管壁是否光滑,主要观察管壁有无斑块。结果随着人们生活水平的提高、运动的减少和环境的污染,各种不健康的食品添加剂的增多及遗传因素,使动脉硬化的发生率增加,且在年龄上有提前趋势。35岁以下出现斑块占正常人的12%;35～45岁出现斑块占正常人的30%;46～55岁出现斑块占正常人的50%;56～65岁出现斑块占正常人的60%;65岁以上出现斑块占正常人的70%。结论早期发现下肢血管病变,对治疗、预后和提高检查者的生活质量具有重要意义。     

Relation of stiffness parameter β to carotid arteriosclerosis and silent cerebral infarction in patients on chronic hemodialysis

Objective   Aortic stiffness measured by pulse wave velocity (PWV) predicts all-cause and cardiovascular mortality in hemodialysis (HD) patients. However, there is a lack of information on stiffness parameter β, another index of arterial stiffness, in HD patients. The aim of the present study was to investigate the clinical usefulness of stiffness parameter β in HD patients. Materials and methods   We compared the relation of stiffness parameter β to carotid intima-media thickness (IMT) and plaque score estimated by carotid ultrasound and investigated the relationship between stiffness parameter β and silent cerebral infarction (SCI) in 64 HD patients. Results   Stiffness parameter β was positively correlated with mean IMT (r = 0.318, P = 0.0113) and plaque score (r = 0.672, P < 0.0001). Stepwise regression analysis revealed that pulse pressure and age were found to be independent determinants of stiffness parameter β (partial correlation coefficients: β = 0.501 and P < 0.0001 for pulse pressure, β = 0.488 and P < 0.0001 for age). In addition, stiffness parameter β in patients with SCI (12.2 ± 3.9) was significantly higher than those (8.0 ± 2.4) in patients without SCI. However, there was no significant difference in mean IMT and plaque score in both groups. Conclusion   These results suggest that arteriosclerosis assessed by stiffness parameter β is associated with atherosclerotic changes of carotid arteries and with the presence of SCI in HD patients.     

老年人颈动脉粥样硬化、超敏C-反应蛋白与脑梗死的关系

目的研究60岁以上老年人不同程度颈动脉粥样硬化、超敏C-反应蛋白（hs-CRP）水平与缺血性脑梗死的关系.方法对200例老年患者行颈动脉彩色超声检查,并检测hs-CRP以及进行头颅CT或MRI扫描.观察不同年龄段患者颈动脉粥样硬化的发生率,分析脑梗死与不同级别颈动脉斑块及hs-CRP水平的关系.结果随年龄增加,患者的颈动脉斑块检出率及2级以上斑块的检出率显著增高（P〈0.01）,有斑块组患者脑梗死发生率显著高于无斑块组（P〈0.01）,斑块级别2级以上的患者其hs-CRP水平显著增高（P〈0.01）,脑梗死组较非脑梗死组患者的hs-CRP水平明显增高（P〈0.01）.结论高龄是动脉粥样硬化加重的重要危险因素.颈动脉粥样硬化与脑梗死密切相关,斑块级别越高,脑梗死发生率越高.颈动脉超声检查有助与判断缺血发生机制和评价危险因素.hs-CRP水平能够提示斑块不稳定性,它与脑梗死的发生、发展密切相关,有望成为脑梗死早期检测和预后判断的生物学指标.     

Acrolein activates matrix metalloproteinases by increasing reactive oxygen species in macrophages

Acrolein is a ubiquitous component of environmental pollutants such as automobile exhaust, cigarette, wood, and coal smoke. It is also a natural constituent of several foods and is generated endogenously during inflammation or oxidation of unsaturated lipids. Because increased inflammation and episodic exposure to acrolein-rich pollutants such as traffic emissions or cigarette smoke have been linked to acute myocardial infarction, we examined the effects of acrolein on matrix metalloproteinases (MMPs), which destabilize atherosclerotic plaques. Our studies show that exposure to acrolein resulted in the secretion of MMP-9 from differentiated THP-1 macrophages. Acrolein-treatment of macrophages also led to an increase in reactive oxygen species (ROS), free intracellular calcium ([Ca²⁺]_i), and xanthine oxidase (XO) activity. ROS production was prevented by allopurinol, but not by rotenone or apocynin and by buffering changes in [Ca²⁺]_I with BAPTA-AM. The increase in MMP production was abolished by pre-treatment with the antioxidants Tiron and N-acetyl cysteine (NAC) or with the xanthine oxidase inhibitors allopurinol or oxypurinol. Finally, MMP activity was significantly stimulated in aortic sections from apoE-null mice containing advanced atherosclerotic lesions after exposure to acrolein ex vivo. These observations suggest that acrolein exposure results in MMP secretion from macrophages via a mechanism that involves an increase in [Ca²⁺]_I, leading to xanthine oxidase activation and an increase in ROS production. ROS-dependent activation of MMPs by acrolein could destabilize atherosclerotic lesions during brief episodes of inflammation or pollutant exposure.     

AT1 blockade attenuates atherosclerotic plaque destabilization accompanied by the suppression of cathepsin S activity in apoE-deficient mice

Although it has been suggested that the renin–angiotensin (RA) system and cathepsins contribute to the development and vulnerability of atherosclerotic plaque, the interaction of the RA system and cathepsins is unclear. Thus, we investigated the effects of an angiotensin II type 1 receptor (AT1) antagonist, olmesartan, on the levels of cathepsins in brachiocephalic atherosclerotic plaque and plaque stabilization in apolipoprotein E (apoE)-deficient mice receiving a high-fat diet.Under a high fat diet, treatment with olmesartan (3 mg/kg per day) maintained collagen and elastin at high levels and attenuated the plaque development and cathepsin S (Cat S) level in the atherosclerotic plaque of apoE-deficient mice. The administration of olmesartan suppressed the accumulation of macrophages in plaque. Immunoreactivities of Cat S and AT1 were observed in macrophages. The amount of Cat S mRNA and the macrophage-mediated collagenolytic and elastolytic activities in cultured macrophages were increased by exposure to angiotensin II (Ang II), and these effects were diminished by olmesartan and the NADPH-oxidase inhibitor apocynin. These results suggested that Cat S derived from macrophages is involved in the mechanisms of atherosclerotic plaque vulnerability, and AT1 blocker maintained the plaque stabilization alongside the suppression of Cat S and macrophage activities.     

Accuracy of quantitative coronary angiography with computed tomography and its dependency on plaque composition

Objective: To determine the impact of plaque composition on accuracy of quantitative 64-slice computed tomography coronary angiography (CTCA). Methods: The institutional review board approved this study; written informed consent was obtained from all patients. One hundred consecutive patients (42 women, mean age 64.6 ± 9.4 years, age range 39–87 years) underwent CTCA and invasive quantitative coronary angiography (QCA) to determine (a) the diagnostic accuracy of CTCA for the detection of significant stenosis (diameter reduction of ≥50%), and (b) the accuracy of stenosis grading. In CTCA stenosis severity was graded in 10% steps and evaluated separately for calcified and non-calcified coronary lesions using Pearson-linear-regression analysis, Bland/Altman-analysis (BA), and Mann-Whitney-U-test. Results: In 60/100 patients 139 significant coronary artery stenoses were identified with QCA. On a per-segment analysis, sensitivity of CTCA was 75.5%, and specificity was 96.6% (positive predictive value: 72.9%, negative predictive value: 97.0%). Quantification of stenosis grading correlated moderately between methods (r = 0.60; P < 0.001), with an overestimation by CTCA of 5.5% (BA limits-of-agreement −29 to 39%). BA limits-of-agreement were greater in calcified lesions (−29.2 to 45.6%; mean error 8.2%) than in non-calcified lesions (−25.9 to 30.2%; mean error 2.2%) and differed significantly (P < 0.05). Conclusions: Diagnostic accuracy of CTCA is high, however agreement for quantitative lesion severity assessment between CTCA and QCA is moderate for calcified but superior for non-calcified lesions.     

Development of integrated backscatter intravascular ultrasound for tissue characterization of coronary plaques

Tissue characterization of plaques of coronary arteries is important to clarify the process of acute coronary syndrome and prevent it. The purpose of this study is to develop an online integrated backscatter intravascular ultrasound (IB-IVUS) system and validate the diagnostic accuracy for the characterization of coronary plaques. A personal computer equipped with custom software was connected to an IVUS imaging system. Images were acquired from 242 segments of 46 coronary arteries from 25 cadavers obtained at autopsy. In the training study, a total of 724 regions-of-interests on color-coded maps were compared with histologic images. In the validation study, a total of 192 cross-sections of coronary arteries were evaluated. Receiver operating characteristic curve analysis showed that the cut-off points of -49 dB (area under curve = 0.98) and -29 dB (area under curve = 0.99) were the most reliable predictors of lipid pools, fibrosis and calcification. In the validation study, the analysis using IB values classified fibrous, lipid-rich and fibrocalcific plaque components with a high accuracy of 93%, 90% and 96%, respectively. The overall agreement between histologic and IB-IVUS diagnoses (n = 175) was high (Cohen's kappa = 0.81). The IB-IVUS system provides high diagnostic accuracy for analysis of tissue characteristics of coronary plaques.     

The influence of text messaging on oral hygiene effectiveness

Objective:To investigate whether text message reminders regarding oral hygiene have an effect on plaque removal in orthodontic patients.Materials and Methods:In this randomized, controlled clinical trial, 50 orthodontic patients were assigned to either a text message or control group. Patients in the text message group received 12 text messages over the course of 4 weeks and one text message for 8 weeks thereafter. Photos were taken at baseline (T0), at 4 weeks after baseline (T1), and at 12 weeks after baseline (T2). For each subject, photos of eight teeth were taken and then the area of the tooth and amount of plaque were measured using planimetry.Results:There was a statistically significant difference in plaque coverage between baseline and both T1 and T2 in the text message group as measured using planimetry. This was demonstrated by comparing the average measurements of the control group and the treatment group.Conclusion:This study demonstrated that the use of automated text message reminders sent from an orthodontic office was effective in improving oral hygiene compliance in orthodontic patients.