Background The purpose of this study was to further elucidate the role of the vascular smooth muscle cells (SMCs) in abdominal aortic aneurysm (AAA) disease. We hypothesized that that AAA SMCs are ...unique and actively participate in the process of degrading the aortic matrix. Methods Whole-genome expression profiles of SMCs from AAAs, nondilated abdominal aorta (NAA), and carotid endarterectomy (CEA) were compared. We quantified elastolytic activity by culturing SMCs in 3 Helastin-coated plates and measuring solubilized tritium in the media after 7 days. Matrix metalloproteinase (MMP)-2 and MMP-9 production was assessed using real-time polymerase chain reaction, zymography, and Western blotting. Results Each SMC type exhibited a unique gene expression pattern. AAA SMCs had greater elastolytic activity than NAA-SMCs (+68%; P < .001) and CEA-SMCs (+45%; P < .001). Zymography showed an increase of active MMP-2 (62 kD) in media from AAA SMCs. AAA SMCs demonstrated twofold greater expression of MMP-2 messenger (m)RNA ( P < .05) and 7.3-fold greater MMP-9 expression ( P < .01) than NAA-SMCs. Culture with U937 monocytes caused a synergistic increase of elastolysis by AAA SMCs (41%; P < .001) but not NAA-SMCs or CEA-SMCs ( P = .99). Coculture with U937 caused a large increase in MMP-9 mRNA in AAA-SMCs and NAA-SMCs ( P < .001). MMP-2 mRNA expression was not affected. Western blots of culture media showed a fourfold increase of MMP-9 (92 kD) protein only in AAA-SMCs/U937 but not in NAA-SMCs/U937 ( P < .001) and a large increase in active-MMP2 (62 kD), which was less apparent in NAA-SMCs/U937 media ( P < .01). Conclusions AAA-SMCs have a unique gene expression profile and a proelastolytic phenotype that is augmented by macrophages. This may occur by a failure of post-transcriptional control of MMP-9 synthesis.
Cardiac malformations occur commonly in Turner syndrome (TS), but the outcomes of cardiac operations and catheter-based procedures are unknown. The Pediatric Cardiac Care Consortium database was ...queried for individuals with TS and other female subjects without genetic abnormalities or syndromes (non-TS NTS). Procedures for left-sided heart lesions represented most TS procedures (95.2%). Three hundred ninety-eight patients with TS who underwent 637 of these procedures of interest were compared with 25,913 female NTS subjects who underwent 56,625 procedures. The numbers of procedures per admission (1.47 vs 1.61, p = 0.01) and per patient (1.85 vs 2.16, p <0.0001) were significantly lower in patients with TS. Procedures for cyanotic heart disease other than hypoplastic left heart (HLH) were performed 4.5-fold less frequently in patients with TS. Patients with TS and NTS subjects had equivalent hospital lengths of stay, except for patients with TS who underwent hypoplastic aortic arch operations, patent ductus arteriosus ligation, pulmonary artery balloon dilation, balloon atrial septostomy, and catheter closure of atrial septal defects. There were 34 deaths among patients with TS and 1,795 among NTS subjects (8.6% vs 7.2%, p = 0.30). When HLH was excluded, mortality was lower in the TS group (3.9% vs 6.5%, p = 0.05). Operations for partial anomalous pulmonary venous connection (14.3% vs 1.9%, p = 0.03) and HLH (90.4% vs 70.5%, p = 0.08) were more likely to result in death in patients with TS. In conclusion, given generally comparable lengths of stay and numbers of procedures as well as uniformly excellent results, these data suggest that the diagnosis of TS does not increase the utilization of limited health care resources. Operations for HLH and partial anomalous pulmonary vein connection carry additional risk for those with TS. These results will permit risk stratification, prognostication, and counseling of individuals with TS and their families.
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