Members of the Wnt/wingless family of secreted proteins act as short-range inducers and long-range organizers during axis formation, organogenesis and tumorigenesis in many developing tissues. Wnt signalling pathways are conserved in nematodes, insects and vertebrates. Despite its developmental significance, the evolutionary origin of Wnt signalling is unclear. Here we describe the molecular characterization of members of the Wnt signalling pathway--Wnt, Dishevelled, GSK3, beta-Catenin and Tcf/Lef--in Hydra, a member of the evolutionarily old metazoan phylum Cnidaria. Wnt and Tcf are expressed in the putative Hydra head organizer, the upper part of the hypostome. Wnt, beta-Catenin and Tcf are transcriptionally upregulated when head organizers are established early in bud formation and head regeneration. Wnt and Tcf expression domains also define head organizers created by de novo pattern formation in aggregates. Our results indicate that Wnt signalling may be involved in axis formation in Hydra and support the idea that it was central in the evolution of axial differentiation in early multicellular animals.
In August 2010, the Nit-Occlud Lê (EUREVECO) became available for transcatheter coil occlusion of ventricular septal defects (VSDs). Retrospective European Registry for VSD Closure using the Nit-Occlud Lê-VSD-Coil; analysis of the feasibility, results, safety and follow-up of VSD-closure over a 3-year period in 18 European centers. In 102 of 111 patients (female 66), successful VSD closure was performed (mean age 8.2 years, mean weight 28.82 kg), 81 perimembranous VSDs (48 with aneurysm), 30 muscular VSDs, mean procedure time was 121.1 min, and mean fluoroscopy time was 26.3 min. Short- and midterm term follow-up was possible in 100/102 patients, there was 1 embolization and 1 explantation after 24 months. Immediate complete closure occurred in 49 of 101 patients (48.5%), trivial residual shunt was present in 51 (50.0%), closure rate was 95% after 6 months and 97% after 1 year. Out of the 102 patients, there were 2 severe complications (1.8%) (1 severe hemolysis, 1 embolization) and 8 moderate/transient (=7.2%) including 1 transient AV block. During a mean follow-up period of 31.3 months (range 24-48) and a total follow-up time of 224.75 patient years, no further problems occurred. VSD closure with the Nit-Occlud Lê VSD coil is feasible and safe with a minimal risk of severe side effects. The long-term effects and safety require further clinical follow-up studies.
Complexes of a N,N-bis(2-picolyl)amine (bpa) derivative with a pendant ethoxyethanol side chain (bpa(CH2)2O(CH2)2OH) (1) with late divalent transition metal ions Co(II), Ni(II), Cu(II) and Zn(II) have been studied. All complexes, [[bpa(CH2)2O(CH2)2OH]Co(NO3)](NO3) (1Co), [[bpa(CH2)2O(CH2)2OH]Ni(NO3)](NO3) (1Ni), [[bpa(CH2)2O(CH2)2OH]Cu(H2O)(NO3)](NO3) (1Cu) and [[bpa(CH2)2O(CH2)2OH]Zn(NO3)](NO3) (1Zn), were comprehensively characterized and their X-ray single crystal structures have been determined. The complexes show hexacoordinated geometries, in which 1 acts as a tetradentate (1Cu) or pentadentate (1Co, 1Ni and 1Zn) ligand. DNA cleavage experiments have been performed on supercoiled double stranded DNA plasmids in order to compare the cleavage efficiency of all four metals in the same ligand environment of 1. In this assay, 1Co and 1Cu showed the highest cleavage efficiency, whereas 1Ni and 1Zn were virtually inactive. Quantification of the gel electrophoresis bands showed that more than 80% of the plasmid has suffered at least one single strand cut in the case of 1Cu, and about 50% of the plasmid was nicked by 1Co. The differential cleavage activity is discussed in relation to the structural findings and a mechanism is proposed for 1Cu.
We conclude that implantation of the Biostar® device is difficult in patients with deficient aortic rims and early complications are similar to those seen in other devices. Of importance, the late complications seen with the Biostar® device might be attributable to specific material and immunological properties of the partially biodegradable device. Although a biodegradable device might theoretically be more favorable more efforts for optimization of these devices have to be taken.
BackgroundPediatric catheterization exposes patients to varying radiation doses. Concerns over the effects of X-ray radiation dose on the patient population have increased in recent years. This study aims at quantifying the patient radiation dose reduction after the introduction of an X-ray imaging technology using advanced real time image noise reduction algorithms and optimized acquisition chain for fluoroscopy and exposure in a pediatric and adult population with congenital heart disease.MethodsPatient and radiation dose data was retrospectively collected (July 2012–February 2013) for 338 consecutive patients treated with a system using state of the art image processing and reference acquisition chain (referred as “reference system”). The same data was collected (March–October 2013) for 329 consecutive patients treated with the new imaging technology (Philips AlluraClarity, referred as “new system”). Patients were divided into three weight groups: A) below 10 kg, B) 10–40 kg, and C) over 40 kg. Radiation dose was quantified using dose area product (DAP), while procedure complexity using fluoroscopy time, procedure duration and volume of contrast medium.ResultsThe new system provides significant patient dose reduction compared to the reference system. Median DAP values were reduced in group A) from 140.6 cGy·cm2 to 60.7 cGy·cm2, in group B) from 700.0 cGy·cm2 to 202.2 cGy·cm2 and in group C) from 4490.4 cGy·cm2 to 1979.8 cGy·cm2 with reduction of 57%, 71% and 56% respectively (p < 0.0001 for all groups).ConclusionsDespite no other changes in procedural approach, the novel X-ray imaging technology provided substantial radiation dose reduction of 56% or higher.
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