Effects of nutrition and ultrasound imaging on the cardiovascular system

[摘要] The work described in this dissertation is focused on two major areas: the biological effects of ultrasound and ultrasound contrast agents, and nutritional interventions to inhibit the development of atherosclerosis.Ultrasound is a highly flexible and affordable imaging modality that has proven clinically useful in many diagnostic situations ranging from pregnancy to cardiovascular disease and cancer. Ultrasound imaging can be performed with concomitant intravenous administration of microbubble contrast agents to improve image clarity. While useful for imaging of the cardiovascular system, concerns have been raised regarding the safety of ultrasound contrast agents, and further research is needed to determine their biological effects. This work investigates interactions between ultrasound, microbubbles, and the vascular endothelium, the inner cellular lining of blood vessels. The goal of this research is to help define the specific conditions under which contrast ultrasound is safe so that this knowledge can be applied to clinical patient care and diagnosis. A series of four studies were conducted to evaluate the effects of ultrasound and ultrasound contrast agents (Chapters 3-6). First, ultrasound imaging was performed on rabbit arteries, and histological and biochemical analyses were used to determine any effects on the tissue being imaged. As part of this project, an assay was developed and validated for measurement of one of the biomarkers, von Willebrand Factor (Chapter 2). Effects of contrast ultrasound on von Willebrand Factor and atheroma thickness were observed. Next, another rabbit study was performed to assess the effect of contrast ultrasound on Hsp70, a cellular stress protein. The ultrasound procedure was hypothesized to elevate Hsp70 protein levels. Hsp70 protein levels were measured in aorta tissue at the site of ultrasound exposure by Western blot. Ultrasound with contrast agent did not affect Hsp70 levels (Chapter 4). In addition to rabbits, work with ApoE-/- mice and rats will be described. We did not observe any adverse effects of ultrasound in these models (Chapters 5 and 6).We also studied the effects of tomato and soy germ on atherosclerosis in ApoE-/- mice (Chapter 7). We did not find that tomato and soy germ decreased atherosclerosis, but soy germ consumption favorably affected plasma and tissue lipid accumulation.

[效力级别] Ultrasound

[关键词] Atherosclerosis;Ultrasound;Imaging;Nutrition;Tomatoes;Soy