A novel 3-dimensional micro-ultrasound approach to automated measurement of carotid arterial plaque volume as a biomarker for experimental atherosclerosis

Baccharis trimera (Less.) DC: An Innovative Cardioprotective Herbal Medicine Against Multiple Risk Factors for Cardiovascular Disease

Cardiovascular disease (CVD) is the leading cause of death worldwide and among its modifiable risk factors are dyslipidemia, diabetes, and smoking. Experimental models evaluated this risk factors singly, however, there is a lack of models that agglomerate these risk factors, resembling real patients and elucidating the pathophysiology of CVD. Moreover, few studies have investigated the cardioprotective effects of Baccharis trimera, a species with lipid-lowering effects. In this study, ethanol-soluble fraction of B. trimera was characterized by liquid chromatography-mass spectrometry. Diabetes was induced by streptozotocin in Wistar rats that also received 0.5% cholesterol-enriched chow and were exposed to the smoke of nine cigarettes, 5 days/week, for 4 weeks. During the last 2 weeks, the animals were treated with vehicle (C^-), B. trimera, or simvastatin plus insulin. At the end, cholesterol, triglyceride, urea, and creatinine levels; blood pressure (BP); heart rate (HR); abdominal aortic morphometry; vascular reactivity; renal and cardiac oxidative status; and histopathological changes were evaluated. The agglomerate of risk factors promoted alterations contrary to those described in the literature for the isolated risk factors. The C^- group exhibited oxidative stress, increase in biochemical parameters, and thickening of the wall of the abdominal aorta. HR, systolic, diastolic, and mean BP decreased, and vascular reactivity was altered. Cardiac and renal histopathological changes were observed. Treatment with B. trimera reversed these changes and this effect may be partially attributable to lipid-lowering action and to the inhibition of free radical generation. B. trimera has cardioprotective effects in this model, with no toxicity.

Carotid plaque volume in patients undergoing carotid endarterectomy

BACKGROUND

The main indication for carotid endarterectomy (CEA) is severity of carotid artery stenosis, even though most strokes in carotid disease are embolic. The relationship between carotid plaque volume (CPV) and symptoms of cerebral ischaemia, and the measurement of CPV by minimally invasive tomographic ultrasound imaging, were investigated.

METHODS

The volume of the endarterectomy specimen was measured using a validated saline suspension technique in patients undergoing CEA. Time from last symptom and severity of stenosis measured by duplex ultrasonography were recorded. Middle cerebral artery emboli were counted using transcranial Doppler imaging (TCD) in a subset of patients.

RESULTS

Some 339 patients were included, 270 with symptomatic and 69 with asymptomatic carotid stenosis. Mean(s.d.) CPV was higher in symptomatic than in asymptomatic patients (0·97(0·43) versus 0.74(0·41) cm³ ; P < 0·001). CPV did not correlate with severity of carotid stenosis (P = 0·770). Mean CPV was highest at 1·03(0·46) cm³ in the 4 weeks following cerebral symptoms, declining to 0·78(0·36) cm³ beyond 8 weeks. Among 33 patients who had TCD, mean CPV was 1·00(0·48) cm³ in the 27 patients with ipsilateral cerebral emboli compared with 0·67(0·16) cm³ in those without (P = 0·142). There was excellent correlation between CPV measured by tomographic ultrasound imaging and the endarterectomy specimen in 34 patients (r = 0·93, P < 0·001).

CONCLUSION

CPV correlated with symptoms of cerebral ischaemia, but not carotid stenosis. It could be a potential indicator for CEA.

Cardiac and vascular phenotypes in the apolipoprotein E-deficient mouse

Cardiovascular death is frequently associated with atherosclerosis, a chronic multifactorial disease and a leading cause of death worldwide. Genetically engineered mouse models have proven useful for the study of the mechanisms underlying cardiovascular diseases. The apolipoprotein E-deficient mouse has been the most widely used animal model of atherosclerosis because it rapidly develops severe hypercholesterolemia and spontaneous atherosclerotic lesions similar to those observed in humans. In this review, we provide an overview of the cardiac and vascular phenotypes and discuss the interplay among nitric oxide, reactive oxygen species, aging and diet in the impairment of cardiovascular function in this mouse model.

The Pathogenesis, Analysis, and Imaging Methods of Atherosclerotic Disease of the Carotid Artery: Review of the Literature

Cerebrovascular (CVA) accidents are the second leading cause of death worldwide and their numbers are increasing. Strokes can arise from several causes, with extracranial carotid artery atherosclerosis (CAS) being one of the leading causes. CAS causes these strokes either by diminishing blood flow distal to the diseased stenotic segment of the artery or, as more recently discovered, by a thromboembolic event of material from the plaque site itself. The specific etiology of CAS is unknown, but causative factors in the formation of atherosclerotic plaque of the carotid arteries have been linked to specific morphological areas within the plaque that may be vulnerable to rupture, leading to thromboemboli into the cerebrovascular circulation. The current means for imaging and reporting CAS is through the measurement of the severity of luminal diameter stenosis caused by atherosclerotic disease. Recent developments in medical imaging techniques have expanded the role of early imaging and detection of CAS. Although current practice uses luminal narrowing as the surrogate marker to assess CAS, it has been recently discovered that plaque morphology and composition may help predict the clinical behavior of CAS and better determine the necessary medical intervention or risk of stroke. Although a single optimized imaging modality for standard CAS imaging has not been established or agreed on, various modalities can provide key elements to a successful exam. This review article will evaluate the most commonly used methods for CAS imaging along with the new and upcoming uses, advantages, and limitations for advanced CAS imaging.

Ultrasound biomicroscopy in small animal research: applications in molecular and preclinical imaging

Ultrasound biomicroscopy (UBM) is a noninvasive multimodality technique that allows high-resolution imaging in mice. It is affordable, widely available, and portable. When it is coupled to Doppler ultrasound with color and power Doppler, it can be used to quantify blood flow and to image microcirculation as well as the response of tumor blood supply to cancer therapy. Target contrast ultrasound combines ultrasound with novel molecular targeted contrast agent to assess biological processes at molecular level. UBM is useful to investigate the growth and differentiation of tumors as well as to detect early molecular expression of cancer-related biomarkers in vivo and to monitor the effects of cancer therapies. It can be also used to visualize the embryological development of mice in uterus or to examine their cardiovascular development. The availability of real-time imaging of mice anatomy allows performing aspiration procedures under ultrasound guidance as well as the microinjection of cells, viruses, or other agents into precise locations. This paper will describe some basic principles of high-resolution imaging equipment, and the most important applications in molecular and preclinical imaging in small animal research.