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The safety and efficacy of a suture-mediated vascular closure device (Perclose, Abbott, Redwood City, CA) for hemostasis after percutaneous vascular access using >or=8-Fr sheath in the femoral vein after cardiac catheterization in children was assessed. Efficacy was determined by time to hemostasis and vessel integrity, using Doppler vascular ultrasound within 24 hours of the procedure. Forty children were randomized to treatment with either the closure device (n = 20, 10 males, weight 34.8 +/- 21 kg) or manual compression (n = 20, 10 males, weight 33.7 +/- 16 kg, P = 0.57 between groups for weight). Sheath sizes used were >or=8 French (8 Fr, n = 8; 9 Fr, n = 7; 10 Fr, n = 1; 11 Fr, n = 1; 12 Fr, n = 2; and 14 Fr, n = 1). Successful suture deployment was achieved in 14 of the 20 children. Mean time to hemostasis was 6.2 +/- 0.9 versus 14.9 +/- 1.1 minutes in controls (P = 0.003). Five of six unsuccessful deployments were in children with weights <20 kg. There were no differences in the occurrence of vascular complications (i.e., intraluminal thrombus) between the two groups as determined by ultrasound. A suture-mediated device appears safe and effective in achieving rapid vascular hemostasis even after the use of large sheath sizes in children.

Pulmonary valve stenosis or atresia with intact ventricular septum represents a spectrum of severity. This study aimed to identify ultrasound markers of biventricular versus non-biventricular outcome. The fetal echocardiograms of 41 fetuses diagnosed with pulmonary stenosis or atresia and right ventricular (RV)/left ventricular (LV) length ratios >0.4 from 17 to 31 weeks of gestation were reviewed. Of 27 live-born patients with intention to treat, 8 had non-biventricular outcomes and 19 had biventricular circulation. At the time of diagnosis, poor RV function, flow reversal in the arterial duct, the degree of tricuspid valve (TV) regurgitation, and inferior vena cava Doppler flow pattern did not differ between the 2 outcome groups. However, RV sinusoids, the RV/LV length ratio, the TV/mitral valve ratio, and TV inflow duration were significantly different. Cut-off values derived from receiver-operating characteristic curves yielding the best sensitivity and specificity for a non-biventricular outcome were TV/mitral valve ratio <0.7, RV/LV length ratio <0.6, TV inflow duration <31.5% of cardiac cycle length, and the presence of RV sinusoids. If 3 of these 4 criteria were fulfilled, this predicted a non-biventricular outcome with sensitivity of 100% and specificity of 75%. In conclusion, in fetuses < or =31 weeks of gestation with pulmonary stenosis or atresia and intact ventricular septum, progression to a non-biventricular outcome can be predicted by a 4-criterion scoring system. The criteria may be useful in selecting fetuses for prenatal catheter intervention to prevent progressive RV hypoplasia.

Myosin binding protein-C (MyBP-C) is a poorly understood component of the thick filament in striated muscle sarcomeres. Its C terminus binds tightly to myosin, whereas the N terminus contains binding sites for myosin S2 and possibly for the thin filament. To study the role of the N-terminal domains of cardiac MyBP-C (cMyBP-C), we added human N-terminal peptide fragments to human and rodent skinned ventricular myocytes. At concentrations >10 micromol/L, the N-terminal C0C2 peptide activated force production in the absence of calcium (pCa 9). Force at the optimal concentration (80 micromol/L) of C0C2 was approximately 60% of that in maximal Ca2+ (pCa 4.5), but the rate constant of tension redevelopment (ktr) matched or exceeded (by up to 80%) that produced by Ca2+ alone. Experiments using different N-terminal peptides suggested that this activating effect of C0C2 resulted from binding by the pro/ala-rich C0-C1 linker region, rather than the terminal C0 domain. At a lower concentration (1 micromol/L), exogenous C0C2 strongly sensitized cardiac myofibrils to Ca2+ at a sarcomere length (SL) of 1.9 microm but had no significant effect at SL 2.3 microm. This differential effect caused the normal SL dependence of myofibrillar Ca2+ sensitivity to be reduced by 80% (mouse myocytes) or abolished (human myocytes) in 1 micromol/L C0C2. These results suggest that cMyBP-C provides a regulatory pathway by which the thick filament can influence the activation of the thin filament, separately from its regulation by Ca2+. Furthermore, the N-terminal region of cMyBP-C can influence the SL-tension (Frank-Starling) relationship in cardiac muscle.

We present COMPUCELL3D, a software framework for three-dimensional simulation of morphogenesis in different organisms. COMPUCELL3D employs biologically relevant models for cell clustering, growth, and interaction with chemical fields. COMPUCELL3D uses design patterns for speed, efficient memory management, extensibility, and flexibility to allow an almost unlimited variety of simulations. We have verified COMPUCELL3D by building a model of growth and skeletal pattern formation in the avian (chicken) limb bud. Binaries and source code are available, along with documentation and input files for sample simulations, at http:// compucell.sourceforge.net.

Treatment for peripheral pulmonary artery stenosis is challenging, and conventional balloon angioplasty has not proved to be universally effective. Evaluated was the efficacy of bladed balloon (BB) dilation to address vessels resistant to conventional high-pressure (10-15 atm) balloon angioplasty (BA). Thirty-one procedures were performed on 14 children with age range 1 month to 15 years. The diameter of the BB ranged from 3 to 8 mm. After BB dilation, all children had subsequent conventional BA (balloon size range, 3-10 mm). The minimal lumen diameter (MLD) before and after the procedure, whether there was a waist at initial BA, and BB diameter-to-MLD ratio before the procedure were measured. A > 50% increase in MLD was considered successful. Four children had Williams syndrome, two children Alagille syndrome, five children Fallot's tetralogy, and three miscellaneous lesions. The resistant stenosis was located in the right central pulmonary artery in 6, right branch pulmonary artery in 7, left central pulmonary artery in 6, and left branch pulmonary artery in 12 lesions. Median BB diameter was 253% (117-440%) of the MLD and increased from 2.0 +/- 0.7 to 3.2 +/- 0.8 mm (P < 0.0001), with a mean increase of 73% +/- 62%. There was an inverse relationship between the MLD before and increase after the procedure (r = 0.75; P < 0.001). The BB diameter-to-MLD ratio before procedure was significantly associated with the increase in MLD (r = 0.70; P < 0.001). After the procedure, 18 of the 31 procedures were considered successful. In all successful procedures, the BB diameter was greater than twice the MLD before the procedure. Comparing children with Williams and Alagille syndrome with the remaining eight children, there were no significant differences in the increase in MLD. A small aneurysm and thrombus were noticed in two and three children, respectively, but no fatal complications were reported. BB angioplasty is effective for resistant peripheral pulmonary artery stenosis when conventional BA fails. The diameter of the BB should be larger than twice the minimal luminal diameter of the stenotic lesion., (Copyright 2004 Wiley-Liss, Inc.)