Sustained reduction of neointima with c-myc antisense oligonucleotides in saphenous vein grafts

BACKGROUND: Treatment of saphenous veins with c-myc antisense oligomers during preparation for grafting reduces medial cellular proliferation and macrophage infiltration, and preserves medial smooth muscle content at 3 days. Accordingly, the purpose of this study was to examine whether c-myc antisense oligomers have an impact on late vein graft remodeling. METHODS: Sixty-two pigs underwent unilateral saphenous vein-carotid artery interposition grafting. Harvested veins were incubated either in saline (control group) or 20-micromol/L or 200-micromol/L concentrations of c-myc antisense oligomers (treated groups) for 30 minutes intraoperatively. Three months after surgery, vein graft histology was assessed. RESULTS: Forty-five of 62 randomized animals survived the experiment; no differences in animal survival or graft patency among the groups were observed (p = NS, chi2). C-myc antisense oligomers significantly decreased neointimal and wall thickness, as well as increased lumenal index, in treated groups (p<0.04, p<0.03, and p<0.001, respectively, analysis of variance). In contrast, there was no difference in medial thickness or perivascular wound healing. CONCLUSION: Intraoperative treatment of saphenous veins with c-myc antisense oligomers decreased neointimal formation at 3 months after grafting. In conjunction with our previous reports, these findings suggest that early inhibition of cellular proliferation and inflammatory infiltration results in a sustained reduction in neointimal formation and favorable graft remodeling.     

Influence of degree of obesity on loss of fat-free mass during very-low-energy diets

This study examined the influence of initial degree of obesity on loss of fat-free mass (FFM). One hundred twelve obese females participated in a series of very-low-energy diet (VLED) clinical trials. Obesity groups were determined by three common methods: percent body fat, body mass index, and weight. Within each group, subjects were classified into low-, intermediate-, and high-obesity groups. As expected, the high-obesity group lost comparable amounts or more weight and more fat weight than the low- and intermediate-obesity classifications for each group. The high-obesity group lost approximately 2% more FFM (P < 0.05) compared with the low and intermediate group when subjects were grouped by body mass index and weight and showed no differences between classifications when subjects were grouped by percent body fat. No differences were found between classifications for ratios of FFM to weight loss regardless of how subjects were grouped. Thus, the degree of obesity does not seem to affect loss of FFM.