Mesenchymal Stem Cells Isolated from a Novel Equine Tissue Exhibit Embryonic Molecular Markers and Adipogenic Differentiation Potential

Mesenchymal stem cells (MSC) have been isolated from equine tissues, most notably adipose and bonemarrow. On the basis of ability for self-renewal, molecular marker expression and differentiation potential, we characterized MSCs isolated from a tissue not yet explored in the equine. After isolation, MSCs weremaintained in culture for 25 passages before senescence was observed. Reverse transcription-PCR revealedembryonic transcription factor Oct4 mRNA, as well as mRNA for fucosyltransferase 4 and ST3B-galactosid α 2,3 sialySSEA4, respylxanthine l ltransferase 2, two enzymes responsible for synthesis of embryonic surface markersSSEA1 and ectively. Treatment with insulin, dexamethasone, indomethacin andisobutylmethed to increased oil red O staining (

Abstract 17357: Magnetic Resonance Imaging Detected Intraplaque Hemorrhage and Expansive Remodeling in Superficial Femoral Artery

Introduction: Compared to coronary and carotid arteries, there is much less knowledge on atherosclerotic plaque characteristics and their clinical relevance in lower-extremity arteries. Magnetic resonance (MR) vessel wall imaging allows for in vivo detection of intraplaque hemorrhage (IPH), which has been consistently associated with increased risks for clinical events in coronary and carotid artery disease. Objective: In a pilot study, we sought to estimate the prevalence of IPH in peripheral artery disease and examine plaque progression in the presence of IPH. Methods: Ten patients with ankle brachial index &lt;0.90 in one or both legs were recruited. A 3D MR imaging protocol with a large coverage (30 or 45 cm in the head-feet direction) and isotropic resolution (voxel size: 0.8x0.8x0.8 mm 3 ) was used to scan bilateral legs in the coronal plane from the common femoral artery bifurcation to the popliteal artery at baseline and 6 months later. Images were reformatted into axial slices for detailed visualization of vessel wall. Following previous publications on carotid MRI, IPH was detected as hyperintense signals on heavily T1-weighted images. Superficial femoral artery (SFA) segments (3 cm in length) with IPH were identified, of which lumen and outer wall were segmented on black-blood images (motion-sensitized flow suppression for improved vessel wall delineation) to measure plaque progression and remodeling. Image analysis was performed in a blinded fashion without knowing time relationship between serial images. Results: Twenty SFAs were analyzed. After excluding 4 arteries with total occlusion, 5 out of the 16 arteries (31%) or 50% of the subjects showed IPH in 1 or more SFA segments. After 6 months, there was significant progression in vessel wall area in SFA segments with IPH (mean ± standard deviation: 43.5 ± 13.9 mm 2 versus 47.3 ± 17.3 mm 2 , p=0.045), which resulted in outer wall expansion (mean [95% confidence intervals]: +3.9 mm 2 [+0.4, +7.4], p=0.035) rather than lumen reduction (-0.02 mm 2 [-2.6, +2.5], p=0.99). Conclusions: MR vessel wall imaging revealed that IPH is likely a common feature in femoral atherosclerosis. SFA segments with IPH showed expansive remodeling in 6 months, of which the clinical significance needs to be further studied. </jats:p

Abstract 576: Gender Differences in Carotid Artery Plaque Composition Do Not Exist in Response to Lipid Lowering Therapy at Two Years Among Men and Women with Carotid or Coronary Artery Disease and Elevated ApoB Levels

Introduction: Recent, age-adjusted stroke death rates declined greater in men than women. Whether this is related to gender differences in the atherosclerotic plaque response to therapy is not known. Postmortem coronary artery histopathology and post-surgical carotid endarterectomy studies demonstrate that women have less calcification and inflammatory cells, but more smooth muscle cells than men. Hypothesis: We hypothesized that gender differences exist in carotid plaque composition (CPC) in response to lipid lowering therapy (LLT) comparing living men and women. Methods: The CPC study is a prospective, randomized study evaluating the effect of LLT: 1) atorvastatin + placebo + placebo vs 2) atorvastatin + niacin ER + placebo 3) atorvastatin + niacin ER + colsevelam on CPC. Participants had coronary or carotid artery disease and ApoB levels ≥120 mg/dL. CPC was evaluated using MRI. The change over two years in % wall volume (PWV) [(wall volume/total vessel volume) х 100%], a measure of plaque burden that adjusts for variation in artery size, and % lipid rich necrotic core (LRNC) volume among slices with LRNC present were evaluated. Statistical analysis used Wilcoxon rank sum test, chi-square, and multivariate linear regression. Results: There were 40 women and 73 men in the study with both baseline and 2 year MRI scans. Women vs. men were older, mean±SD age 58±9 vs. 54±8 yrs. (p=0.009), had higher HDL-C, 49±14 vs. 40±11 mg/dL (p=0.002), and higher ApoA1 145±26 vs. 126±20 mg/dL (p&lt;0.001). ApoB levels were not significantly different, 127±31 vs. 121±25 mg/dL (p=0.2). Adjusted for age, HDL-C (strongly correlated with ApoA1, r=0.89), ApoE, prevalence of MI and metabolic syndrome (statistically significant in the full baseline cohort), there were no statistically significant gender differences at 2 years with LLT in change in PWV, [[Unable to Display Character: &amp;#8710;]] -0.1 (95% CI: -0.7, 0.6%) (p=0.8) or %LRNC among participants with LRNC, [[Unable to Display Character: &amp;#8710;]] 0.5 (95% CI: -2.5, 3.5%) (p=0.7). Conclusions: We did not detect statistically significant gender differences in change in PWV and %LRNC in response to LLT. Although the results are consistent with no gender differences they remain inconclusive due to the small sample size. Further gender studies in the biology and treatment of arterial atherosclerosis are needed. </jats:p