Alien Registration- Buckingham, Margaret A. (Wade, Aroostook County)

https://digitalmaine.com/alien_docs/32595/thumbnail.jp

Redefining the Genetic Hierarchies Controlling Skeletal Myogenesis: Pax-3 and Myf-5 Act Upstream of MyoD

AbstractWe analyzed Pax-3 (splotch)Myf-5 (targeted with nlacZ), and splotch/Myf-5 homozygous mutant mice to investigate the roles that these genes play in programming skeletal myogenesis. In splotch and Myf-5 homozygous embryos, myogenic progenitor cell perturbations and early muscle defects are distinct. Remarkablysplotch/Myf-5 double homozygotes have a dramatic phenotype not seen in the individual mutants: body muscles are absent. MyoD does not rescue this double mutant phenotype since activation of this gene proves to be dependent on either Pax-3 or Myf-5. ThereforePax-3 and Myf-5 define two distinct myogenic pathways, and MyoD acts genetically downstream of these genes for myogenesis in the body. This genetic hierarchy does not appear to operate for head muscle formation

A Pax3/Dmrt2/Myf5 Regulatory Cascade Functions at the Onset of Myogenesis

All skeletal muscle progenitor cells in the body derive from the dermomyotome, the dorsal epithelial domain of developing somites. These multipotent stem cells express Pax3, and this expression is maintained in the myogenic lineage where Pax3 plays an important role. Identification of Pax3 targets is therefore important for understanding the mechanisms that underlie the onset of myogenesis. In a microarray screen of Pax3-GFP sorted cells, with analysis on Pax3 gain and loss of function genetic backgrounds, we identify Dmrt2, expressed in the dermomyotome, as a Pax3 target. In vitro gel shift analysis and chromatin immunoprecipitation with in vivo extracts show that Pax3 binds to a conserved 286 bp sequence, situated at −18 kb from Dmrt2. This sequence directs reporter transgene expression to the somite, and this is severely affected when the Pax3 site is mutated in the context of the locus. In Dmrt2 mutant embryos, somite maturation is perturbed and the skeletal muscle of the myotome is abnormal. We now report that the onset of myogenesis is also affected. This depends on activation, in the epaxial dermomyotome, of the myogenic determination gene, Myf5, through its early epaxial enhancer. This sequence contains sites that bind Dmrt2, which belongs to the DM class of DNA–binding proteins. Mutation of these sites compromises activity of the enhancer in transgenic embryos where the reporter transgene is under the control of the Myf5 epaxial enhancer. Transactivation of this site by Dmrt2 is demonstrated in vitro, and conditional overexpression of Dmrt2 in Pax3 expressing cells in the somite confirms the role of this factor in the activation of Myf5. These results reveal a novel genetic network, comprising a Pax3/Dmrt2/Myf5 regulatory cascade that operates in stem cells of the epaxial dermomyotome to initiate skeletal muscle formation

Barriers to the use of e-health technology in nurse practitioner_patient consultations

Purpose This paper examines primary care nurse practitioners' (NPs') use of information available via e-health technology (EHT) within consultations. It explores which information resources NPs use in clinical decision making, their comparative use of electronic versus paper-based and human information resources, the reasons behind their choices and how the use of different resources impacts on patient interactions. Methods Semi-structured interviews were undertaken with 12 NPs recruited from 11 different general practitioner (GP) practices and five primary care trusts (PCTs) within the West Midlands South Strategic Health Authority, UK. Findings The key finding was that for NPs an effective information resource is one that provides sufficient information to generate a patient management plan rapidly. Speed, familiarity and trust are vital ingredients for regular use. Paper-based information resources therefore retain a significant role, and together with human information resources are still more frequently used than most electronic, and particularly web-based, resources. The latter are not yet well established within the context of patient consultations. Electronic clinical support systems (such as Mentor, PRODIGY and GP notebook) are regularly used, however, because they are often linked electronically to patient records, and generate brief information in a form accessible to both nurses and patients. By contrast, searching for information from web-based resources was considered time-consuming, technically difficult and disruptive to patients. All NPs reported some negative effects on patients of using computers: mostly disrupted rapport and longer consultations. However, the majority had developed ways of working to overcome these difficulties and that helped them to maintain their patient-centred focus. Conclusions Study NPs had received only very limited information technology (IT) training, but nevertheless were enthusiastic about computer use. This suggests that with further training they could adapt their practice to embrace more EHT, which would enhance their ability to be more autonomous and to base their practice on sound clinical evidence