【摘要】 目的 探討血尿酸水平、頸動脈斑塊與冠心病之間的關系。 方法 收集2006年1月-2009年12月擬診為冠心病的住院患者280例,冠狀動脈造影檢查冠狀動脈狹窄程度gt;50%的194例為冠心病組,冠狀動脈無狹窄或狹窄程度lt;50%的86例為對照組;冠心病組又分為單支、雙支、多支病變亞組。分別測定冠心病組與對照組頸總動脈與頸動脈分叉處內膜中層厚度(IMT)、等級評分、Crouse積分、血尿酸濃度。結果 與對照組相比,冠心病組頸總動脈與頸動脈分叉處IMT、等級評分、Crouse積分、血尿酸濃度均高于對照組,差異有統計學意義。在冠心病組,隨病變分支的增多,頸動脈超聲檢查指標與血尿酸隨之升高(Plt;0.05或0.01)。 結論 頸動脈IMT、等級評分、Crouse積分、血尿酸濃度與冠心病相關,是冠心病的獨立危險因素。【Abstract】 Objective To investigate the relationships between serum uric acid levels, carotid artery plaque and coronary heart disease (CHD). Methods 194 patients with CHD and 86 nonCHD patients were selected through coronary angiography in patients with essential hypertension. CHD group was divided into three subgroups including a single branch, doublebranch and multivessel disease. Intimamedia thickness (IMT) of carotid artery and carotid bifurcation, grade score, Crouse score, serum uric acid concentrations were detected in patients with coronary heart disease and control group. Results IMT of carotid artery and carotid bifurcation, grade score,crouse score, serum uric acid concentrations were higher in CHD group than that in control group, and the difference was statistically significant. In the CHD group, ultrasound parameters of carotid artery and serum uric acid increased with the increase in branch lesions (Plt;005 or 001). Conclusions Carotid IMT, grade score, Crouse score, serum uric acid concentration relate to coronary heart disease, which is an independent risk factor for coronary heart disease, respectively.
Intravascular ultrasound (IVUS) is widely used in coronary artery examination. Ultrasonic elastography combined with IVUS is very conspicuous in identifying plaque component and in detecting plaque vulnerability degree. In this study, a simulation model of the blood vessel based on finite element analysis (FEA) was established. The vessel walls generally have radial changes caused by different intravascular pressure. The signals at lower pressures were used as the pre-deformation data and the signals at higher pressure were used as the post-deformation data. Displacement distribution was constructed using the time-domain cross-correlation method, and then strain images. By comparison of elastograms under different pressures, we obtained the optimal pressure step. Furthermore, on the basis of the obtained optimize pressure step, the simulation results showed that this method could effectively distinguish characteristics between different component plaques, and could guide the later experiments and clinical applications.
Atherosclerotic plaque rupture is the main cause of many cardiovascular diseases, and biomechanical factors play an important role in the process of plaque rupture. In the study of plaque biomechanics, there are relatively few studies based on fatigue fracture failure theory, and most of them mainly focus on the whole fatigue propagation process from crack initiation to plaque rupture, while there are few studies on the influence of crack on plaque rupture at a certain time in the process of fatigue propagation. In this paper, a two-dimensional plaque model with crack was established. Based on the theory of fracture mechanics and combined with the finite element numerical simulation method, the stress intensity factor (SIF) and related influencing factors at the crack tip in the plaque were studied. The SIF was used to measure the influence of crack on plaque rupture. The results show that the existence of crack can lead to local stress concentration, which increases the risk of plaque rupture. The SIF at the crack tip in the plaque was positively correlated with blood pressure, but negatively correlated with fibrous cap thickness and lipid pool stiffness. The effect of the thickness and angle of lipid pool on the SIF at the crack tip in the plaque was less than 4%, which could be ignored. This study provides a theoretical basis for the risk assessment of plaque rupture with cracks.
Atherosclerosis is a complex and multi-factorial pathophysiological process. Researches over the past decades have shown that the development of atherosclerotic vulnerable plaque is closely related to its components, morphology, and stress status. Biomechanical models have been developed by combining with medical imaging, biological experiments, and mechanical analysis, to study and analyze the biomechanical factors related to plaque vulnerability. Numerical simulation could quantify the dynamic changes of the microenvironment within the plaque, providing a method to represent the distribution of cellular and acellular components within the plaque microenvironment and to explore the interaction of lipid deposition, inflammation, angiogenesis, and other processes. Studying the pathological mechanism of plaque development would improve our understanding of cardiovascular disease and assist non-invasive inspection and early diagnosis of vulnerable plaques. The biomechanical models and numerical methods may serve as a theoretical support for designing and optimizing treatment strategies for vulnerable atherosclerosis.
In recent years, optical coherence tomography (OCT) has developed into a popular coronary imaging technology at home and abroad. The segmentation of plaque regions in coronary OCT images has great significance for vulnerable plaque recognition and research. In this paper, a new algorithm based on K-means clustering and improved random walk is proposed and Semi-automated segmentation of calcified plaque, fibrotic plaque and lipid pool was achieved. And the weight function of random walk is improved. The distance between the edges of pixels in the image and the seed points is added to the definition of the weight function. It increases the weak edge weights and prevent over-segmentation. Based on the above methods, the OCT images of 9 coronary atherosclerotic patients were selected for plaque segmentation. By contrasting the doctor’s manual segmentation results with this method, it was proved that this method had good robustness and accuracy. It is hoped that this method can be helpful for the clinical diagnosis of coronary heart disease.
ObjectiveTo study the correlation between neck artery vascular sclerosis and homocysteine levels in hypertensive patients.
MethodsA total of 2 132 patients with hypertension participated in the program of "Stroke screening and prevention in Dongying city" were included from Sep. 2012 to Jan. 2013. Questionnaire, physical examination, biochemical blood tests and carotid artery ultrasound were conducted in all included patients. According to the level of homocysteine (Hcy), patients were divided into three groups:716 patients with Hcy level less than 12.3 mm/L were in Group 1, 703 patients with Hcy level 12.3 to 16.5 mm/L were in Group 2, and 713 patients with Hcy level more than 16.5 mm/L were in Group 3. The influence of Hcy levels on carotid atherosclerosis was analyzed.
Results① The prevalence rate for carotid plaques in Groups 1, 2, and 3 were 50.28%, 60.03% and 65.36%, respectively. The prevalence rate for carotid plaques in Group 2 was higher than that in Group 1 with a statistical difference (OR=1.485, 95% CI 1.203 to 1.833, P=0.000). The prevalence rate in Group 3 was also higher than that in Group 1 with a statistical difference (OR=1.866, 95% CI 1.508 to 2.308, P=0.000). ② The prevalence rate for carotid plaques was 62.24% in the rural population, and 52.39% in the urban population. The difference between urban and rural populations was statistically significant (OR=1.500, 95% CI 1.259 to 1.788, P=0.000). ③ Using the presence of carotid plaques as a dependent variable and Hcy level as a covariant, logistic regression analysis found that the plaque formation in Group 2 was 1.491 times than in Group 1 and the plaque formation in Group 3 was 1.752 times than in Group 1. After adjusting the risk factors (gender, age, BMI, TG, TC, LDL-C, HDL-C and blood sugar level), the results showed that the plaque formation in Group 2 was 1.388 times than in Group 1, and the plaque formation in Group 3 was 1.452 times than in Group 1.
ConclusionThere is a correlation between the increased incidence of carotid plaque and homocysteine levels in patients with hypertension. The incidence of carotid plaque in the rural population with hypertension is higher than that in the urban population. In the population with hypertension, high homocysteine level is an independent risk factor for the formation of carotid plaques.
A method of ultrasonic simulation based on the FIELD II software platform for carotid artery plaque was proposed according to the analysis for geometrical shape, tissue characteristics and acoustic properties of carotid artery plaques in clinic, and then a simulation system was developed by using the MATLAB graphical user interface (GUI). In the simulation and development, a three-dimensional geometric model of blood vessel with plaques was set up by using the metaball implicit surface technique, and a tissue model was established based on the scatterers with spatial position of gamma random distribution. Comparison of the statistical and geometrical characteristics from simulated ultrasound B-mode images with those based on clinical ones and preset values, the results fully demonstrated the effectiveness of the simulation methods and system.
Objective To assess the efficacy and safety of efalizumab in the treatment of psoriasis. Methods Randomized controlled trials (RCT) on efalizumab in the treatment of psoriasis were identified from The Cochrane Library ( issue 1, 2006) , specialized trials registered in Cochrane Skin Group (2006), MEDLINE (1966 - 2006) and EMBASE (1974 - 2006). The quality of the trials was assessed by two reviewers independently. RevMan 4.2.7 software provided by the Cochrane Collaboration was used for statistical analysis. Results Three RCTs involving 1 651 patients were included, all of which were of high methodological quality. All the patients were diagnosed as chronic moderate to severe plaque psoriasis with the age of 18-75 years. Meta-analysis indicated that at week 12, significantly more patients in both 1mg/kg/w and 2 mg/kg/w efalizumab subcutaneous groups achieved PASI50, PASI75, PASI90 improvement compared to the placebo group (Plt;0.0001), while there was no significant difference in PASI50, PASI75 and PASI90 responses between 1mg and 2mg efalizumab groups (P gt;0.05). No serious adverse effects were identified. Extended treatment for another 12w may contribute to further efficacy without increasing toxicty. Conclusions Efalizumab 12w therapy is safe and effective for treating adult patients with moderate to severe plaque psoriasis. More RCTs are required to assess the efficacy of the extended treatment.
Objective To assess efficacy of a mouthwash containing 0.1% cetylpiridinium on gingivitis and plaque and its safety. Methods Multi-center randomized double-blind trial with positive control and split-mouth comparison was designed. Scaling on teeth of left side were conducted at do then on those of right side at D8. The cases rinsed five times a day in same way with assigned agents. Efficacy was measured using before-after differences of clinical and microbial variables. Re-examinations were scheduled at D4 and D8. Brushing was refrained between D0 and D4, resumed between D4 and D8. Results There were 144 patients with gingivitis included, 4 lost follow up. Data of 69 cases in test group and 71 in control group could be analyzed. Baseline data analysis showed that distributions of sex, age and values of clinical and microbial variables in both groups were well comparable. At D4 plaque accumulations of the scaled side in both groups were in same level, and Gingival index (GI), sulcus bleeding index (SBI) and VAS for halitosis were significantly reduced. At D8 the measurements of plaque index (PI), GI, SBI and VAS of halitosis decreased significantly more than those of D4. More than half of the suspected pathogenic strains were eliminated and log value of its CFU/ml decreased significantly but at same level in both groups. The balance of intra-oral bacterial flora was not disturbed. Seventeen cases in test group (24.6%) had minor and transient adverse reactions related to the mouthwash. Antimicrobial tests in vitro confirmed that the test agent could kill or inhibit growth of the pathogenic bacteria involving with oropharyngeal infection, gingivitis, periodontal diseases and caries. Conclusion The mouthwash containing cetylpiridinium could inhibit plaque, reduce severity of gingivitis and halitosis, with acceptable minor adverse reactions, similar to those of the marketed cetylpiridinum solution.
The present paper intends to discuss the antioxidant and tyrosinase inhibition effect of solanesol from three aspects of ultraviolet radiation and free radical scavenging. The paper makes a survey on diurnal variation rule of the minimum ultraviolet transmittance and ultraviolet transmittance of solanesol, hydroxyl (·OH) free radical scavenging method of Smirnoff reaction system model, superoxide anion O2-· free radical scavenging method of pyrogallol autoxidation, and the inhibitory effect of solanesol on tyrosinase activity by enzyme kinetic method. The experiment results showed that solanesol could effectively scavenge lipid radicals to block lipid peroxidation, and inhibit effects on tyrosinase. Solanesol is a natural extract which could be used to prevent senile atrophy of human skin and senile plaque.
