Browsing by keyword "Tunica Media"
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Differential associations of weight dynamics with coronary artery calcium versus common carotid artery intima-media thickness: The CARDIA StudyChange and fluctuation in body mass index (BMI; weight (kg)/height (m)(2)) may be associated differently with coronary artery calcification (CAC) than with carotid artery intima-media thickness (IMT). The authors analyzed data on 2,243 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) Study, initially aged 18-30 years, who were examined every 2-5 years over a 20-year period (1985-2006). BMI at year 0 was associated positively and linearly with CAC at year 20; however, the association of BMI with year 20 CAC became progressively U-shaped in subsequent examinations (years 10, 15, and 20). To understand the deepening U shape, the authors modeled year 20 BMI and its history using 3 indices: year 0 BMI, linear slope of BMI during 20 years, and BMI fluctuation during 20 years. In models including these 3 terms, year 0 BMI was associated positively with CAC, as was BMI fluctuation. However, adjusted odds ratios across quintiles of BMI slope (vs. the lowest quintile) were 0.7, 0.4, 0.5, and 0.4 (P(trend) < 0.01), suggesting higher risk of CAC with weight loss, plateauing after moderate weight gain. In contrast, IMT was associated positively with BMI at all examinations and with 20-year BMI slope and was unassociated with BMI fluctuation. Surprisingly, CAC risk was higher with BMI loss and lower with BMI gain, whereas associations with IMT were as expected.
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Interleukin 18 binding protein (IL18-BP) inhibits neointimal hyperplasia after balloon injury in an atherosclerotic rabbit modelOBJECTIVES: Interleukin 18 (IL18) is an interferon (IFN)-gamma-inducing factor and a proinflammatory and proatherogenic cytokine. IL18 binding protein (IL18-BP) functions as an IL18 inhibitor. This study was designed to investigate whether systemic administration of IL18-BP could inhibit neointimal hyperplasia and arterial lipid deposition. METHODS: New Zealand white, male rabbits were fed with a 21% fat, 0.15% cholesterol diet. The left superficial femoral artery (SFA) was de-endotheliazed with a 2F arterial embolectomy catheter. IL18-BP (5 microg, 10 microg, or 25 microg), or 0.9% saline (control) was administered by i.v. bolus during surgery. Rabbits were followed-up at 2 and 4 weeks. Intima-media (I/M) and lumen-whole artery (L/A) area ratios, and luminal areas were measured. Serum lipid levels, liver enzymes, and kidney function were evaluated. Inflammatory cells were quantified and further verified with immunohistofluorescence staining. The extent of lipid deposition in the artery wall was quantified with Oil Red O (ORO) staining employing Zeiss AxioVision 4.6.3. Image analysis software. Lipid laden cells including macrophages were evaluated by transmission electron microscopy (TEM). RESULTS: Intravenous IL18-BP 5 microg, 10 microg, and 25 microg significantly reduced I/M ratios compared with the control group at both 2 and 4 weeks. There was no significant difference between the 5 microg and 10 microg dose groups. However, at 10 microg, IL18-BP significantly increased L/A ratio more than either the 5 microg IL18-BP or control groups. The high fat diet caused significant elevation of serum lipids at 4 and 6 weeks. IL18-BP had no effect on blood lipid levels. Lipid deposit in the thoracic aorta of the control group at 6 weeks was more than at 4 weeks (P = .025). Administration of IL18-BP inhibited the lipid deposition at 4 weeks (not significant) and 6 weeks (P = .012 to .008) compared with its control group. Lipid laden macrophages (foam cells), as well as endothelial cells and smooth muscle cells were seen in the descending thoracic aorta after 6 weeks of a high fat diet by ORO, immunohistofluorescence staining, and TEM. The lipid laden cells were not seen in either of IL18-BP groups. IL18-BP 10 microg significantly inhibited mono/macro adherence and infiltration in the SFA after balloon-injury at 2 weeks after surgery. CONCLUSION: A single intravenous dose of IL18-BP significantly decreased arterial neointimal hyperplasia, improved lumen to artery ratio after balloon-injury and also prevented arteriosclerosis progression. CLINICAL RELEVANCE: A single intravenous dose of IL18BP decreased neointimal hyperplasia and improved arterial L/A ratios in an atherosclerotic balloon-injury animal model. These preliminary results suggest that IL18BP may be a promising molecular approach to inhibit neointimal hyperplasia and arteriosclerosis progression following coronary and peripheral angioplasty.