BACKGROUND: Focused transthoracic echocardiography (F-TTE) is an important tool to assess hemodynamically unstable patients in the Emergency Department. Although its scope has been defined by the American College of Emergency Physicians, more research is needed to define an optimal F-TTE training program, including assessment of proficiency. OBJECTIVE: The goal of this study was to determine the effectiveness of current standards in post-residency training to reach proficiency in F-TTE. METHODS: Fourteen staff Emergency Physicians were enrolled in a standardized teaching curriculum specifically designed to meet the 2008 American College of Emergency Physicians' guidelines for general ultrasound training applied to echocardiography. This training program consisted of 6 h of didactics and 6 h of scanning training, followed by independent scanning over a 5-month period. Acquisition of echocardiographic knowledge was assessed by an online pre- and post-test. At the conclusion of the study, a hands-on skills test assessed the trainees' ability to perform and interpret F-TTE. RESULTS: Ninety percent of trainees passed the written post-test. Two views, the parasternal long and short axis, were easily obtainable, regardless of the level of training or the number of ultrasounds completed. Other views were more difficult to master, but strong trends toward increased competency were evident after 10 h of mixed didactic and scanning training and > 45 ultrasounds. CONCLUSIONS: A short, 12-h didactic training in F-TTE provided proficiency in image interpretation and in obtaining adequate images from the parasternal window. More extensive training is needed to master the apical and subcostal windows in a timely manner.
[Show abstract][Hide abstract] ABSTRACT: The genes alg-1 and alg-2 (referred to as "alg-1/2") encode the Argonaute proteins affiliated to the microRNA (miRNA) pathway in C. elegans. Bound to miRNAs they form the effector complex that effects post-transcriptional gene silencing. In order to define biological features important to understand the mode of action of these Argonautes, we characterize aspects of these genes during development. We establish that alg-1/2 display an overlapping spatio-temporal expression profile and shared association to a miRNAs set, but with gene-specific predominant expression in various cells and increased relative association to defined miRNAs. Congruent with their spatio-temporal coincidence and regardless of alg-1/2 drastic post-embryonic differences, only loss of both genes leads to embryonic lethality. Embryos without zygotic alg-1/2 predominantly arrest during the morphogenetic process of elongation with defects in the epidermal-muscle attachment structures. Altogether our results highlight similarities and specificities of the alg-1/2 likely to be explained at different cellular and molecular levels.
PLoS ONE 03/2012; 7(3):e33750. DOI:10.1371/journal.pone.0033750 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The extracellular matrix (ECM) plays an essential role in organizing tissues, defining their shapes or in presenting growth factors. Their components have been well described in most species, but our understanding of the mechanisms that control ECM remodeling remains limited. Likewise, how the ECM contributes to cellular mechanical responses has been examined in few cases. Here, I review how studies performed in C. elegans have brought several significant advances on those topics. Focusing only on epithelial cells, I discuss basement membrane invasion by the anchor cell during vulva morphogenesis, a process that has greatly expanded our knowledge of ECM remodeling in vivo. I then discuss the ECM role in a novel mechanotransduction process, whereby muscle contractions stimulate the remodeling of hemidesmosome-like junctions in the epidermis, which highlights that these junctions are mechanosensitive. Finally, I discuss progress in defining the composition and potential roles of the apical ECM covering epidermal cells in embryos.
[Show abstract][Hide abstract] ABSTRACT: α-catenin is central to recruitment of actin networks to the cadherin-catenin complex, but how such networks are subsequently stabilized against stress applied during morphogenesis is poorly understood. To identify proteins that functionally interact with α-catenin in this process, we performed enhancer screening using a weak allele of the C. elegans α-catenin, hmp-1, thereby identifying UNC-94/tropomodulin. Tropomodulins (Tmods) cap the minus ends of F-actin in sarcomeres. They also regulate lamellipodia, can promote actin nucleation, and are required for normal cardiovascular development and neuronal growth-cone morphology. Tmods regulate the morphology of cultured epithelial cells, but their role in epithelia in vivo remains unexplored. We find that UNC-94 is enriched within a HMP-1-dependent junctional-actin network at epidermal adherens junctions subject to stress during morphogenesis. Loss of UNC-94 leads to discontinuity of this network, and high-speed filming of hmp-1(fe4);unc-94(RNAi) embryos reveals large junctional displacements that depend on the Rho pathway. In vitro, UNC-94 acts in combination with HMP-1, leading to longer actin bundles than with HMP-1 alone. Our data suggest that Tmods protect actin filaments recruited by α-catenin from minus-end subunit loss, enabling them to withstand the stresses of morphogenesis.
Current biology: CB 07/2012; 22(16):1500-5. DOI:10.1016/j.cub.2012.06.025 · 9.57 Impact Factor
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