Stent implantation and balloon angioplasty for treatment of branch pulmonary artery stenosis in children

Objectives: Comparison of the results of branch pulmonary artery stenosis treated with balloon angioplasty (BA) or stent implantation (SI) in children. Background: Branch pulmonary artery stenosis may be treated with BA or SI. Methods: We compared the results of 147 interventions of branch pulmonary artery stenosis in 87 children (median age 3.6 years). Patients were treated during 1989-2000 with BA and during 2001-2004 with SI. Primary endpoints were acute complications and reintervention during follow up. Secondary variables were age, vessel diameter increase, acute success rate, balloon/vessel diameter ratio, pulmonary artery hypoplasia indices, and procedure related factors. Results: The acute vessel diameter increase with BA (4.31 ± 1.98 vs. 7.15 ± 2.31 mm) and SI (3.71 ± 1.58 vs. 6.97 ± 2.68 mm) was significant within both groups (P < 0.001), but not between both groups. The reintervention rate was comparable between both groups, but median time to reintervention was shorter after SI in infants compared to BA. The balloon/vessel diameter ratio was on average higher in BA than the stent/vessel diameter ratio in SI (3.49 ± 2.16 vs. 2.42 ± 0.56; P < 0.05) and was a significant risk factor (P < 0.01) for the higher complication rate after BA (BA: 14.1% vs. SI: 4.8%). No mortality occurred in both groups. Conclusion: BA and SI are safe interventional catheter therapies of branch pulmonary artery stenosis. The immediate results of BA and SI are comparable. The higher complication rate after BA, especially in infants, was associated with a higher balloon/vessel diameter ratio. SI seems to be a safe permanent alternative with foreign material, but requires more reinterventions in infants due to its therapeutic strateg

Performance characterization and modeling of the molecular simulation code opal

In modern parallel computing there exists a large number of highly different platforms and it is im-portant to choose the right parallel platform for a computationally intensive code. To decide about the most cost effective parallel platform, a computer scientist needs a precise characterization of the appli-cation properties, such as memory usage, computation and communication requirements. The computer architects need this information to provide the community with new, more cost effective platforms. The precise resource usage is of little interest to the users or computational scientists in the applied field, so most traditional parallel codes are ill equipped to collect data about their resource usage and behavior at run time. Once an application runs, is numerically stable and there is some speedup, most computational scientists declare victory and move on to the next application. Contrary to that philosophy, our group of computer architects invested a considerable amount of effort and time to instrument Opal, a paral-lel molecular biology simulation code, for an accurate performance characterization on a given parallel platform. As a result we can present a simple analytical model for the execution time of that particular application code along with an in depth verification of that model through measured execution times. The model and measurements can not only be used for performance tuning but also for a good prediction of the code’s performance on alternative platforms, like newer and cheaper parallel architectures or the next generation of supercomputers to be installed at our site.

Dandy-Walker (like) malformation, atrio-ventricular septal defect and a similar pattern of minor anomalies in 2 sisters: A new syndrome?

We report on sisters with similar craniofacial anomalies, a brain malformation in the area of the posterior fossa, and a congenital heart defect. The craniofacial findings include macrocephaly, a prominent forehead and occiput, foramina parietalia, hypertelorism, downslanting palpebral fissures, a depressed nasal bridge, narrow palate, and apparently low-set ears. Patient 1 had a Dandy-Walker malformation with communicating hydrocephalus, aplasia of the posterior portion of the cerebellar vermis, and high insertion of the confluent sinus, while in patient 2, a Dandy-Walker variant was found with aplasia of the cerebellar vermis and hypoplasia of the hemispheres, large cisterna magna, high insertion of the confluent sinus, but no hydrocephalus. Both sibs were moderately mentally retarded. The older sister had a complete atrio-ventricular canal and died after unsuccessful heart operation at 3 1/2 years. The younger had a successful operation on a cleft mitral valve and septum primum defect. Chromosomes were normal. The occurrence of a distinct and similar pattern of congenital anomalies in sisters born to healthy parents points toward a "new" syndrome caused by the homozygous state of an autosomal recessive gene