10 research outputs found

    Circular frame fixation for calcaneal fractures risks injury to the medial neurovascular structures: a cadaveric description

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    Aim: There is a risk of iatrogenic injury to the soft tissues of the calcaneus and this study assesses the risk of injury to these structures in circular frame calcaneal fracture fixation. Materials and Methods: After olive tip wires were inserted, an L-shaped incision on the lateral and medial aspects of 5 formalin fixed cadaveric feet was performed to expose the underlying soft tissues. The calcaneus was divided into zones corresponding to high, medium and low risk using a grading system. Results: Structures at high risk included the posterior tibial artery, posterior tibial vein and posterior tibial nerve on the medial aspect. Soft tissue structures on the lateral side that were shown to be at lower risk of injury were the small saphenous vein and the sural nerve and the tendons of fibularis longus and fibularis brevis. Conclusion: The lateral surface of the calcaneus provides a lower risk area for external fixation. The risk of injury to significant soft tissues using a circular frame fixation approach has been shown to be greater on the medial aspect. Clinical Relevance: This study highlights the relevant anatomical relations in circular frame fixation for calcaneal fractures to minimize damage to these structures

    Egocentric Perception using a Biologically Inspired Software Retina Integrated with a Deep CNN

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    We presented the concept of of a software retina, capable of significant visual data reduction in combination with scale and rotation invariance, for applications in egocentric and robot vision at the first EPIC workshop in Amsterdam [9]. Our method is based on the mammalian retino-cortical transform: a mapping between a pseudo-randomly tessellated retina model (used to sample an input image) and a CNN. The aim of this first pilot study is to demonstrate a functional retina-integrated CNN implementation and this produced the following results: a network using the full retino-cortical transform yielded an F1 score of 0.80 on a test set during a 4-way classification task, while an identical network not using the proposed method yielded an F1 score of 0.86 on the same task. On a 40K node retina the method reduced the visual data bye×7, the input data to the CNN by 40% and the number of CNN training epochs by 36%. These results demonstrate the viability of our method and hint at the potential of exploiting functional traits of natural vision systems in CNNs. In addition, to the above study, we present further recent developments in porting the retina to an Apple iPhone, an implementation in CUDA C for NVIDIA GPU platforms and extensions of the retina model we have adopted

    Inhibition of destructive autoimmune arthritis in Fc?RIIa transgenic mice by small chemical entities

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    The interaction of immune complexes with the human Fc receptor, Fc?RIIa, initiates the release of inflammatory mediators and is implicated in the pathogenesis of human autoimmune diseases, including rheumatoid arthritis and systemic lupus erythematosus, so this FcR is a potential target for therapy. We have used the three-dimensional structure of an Fc?RIIa dimer to design small molecule inhibitors, modeled on a distinct groove and pocket created by receptor dimerization, adjacent to the ligand-binding sites. These small chemical entities (SCEs) blocked immune complex-induced platelet activation and aggregation and tumor necrosis factor secretion from macrophages in a human cell line and transgenic mouse macrophages. The SCE appeared specific for Fc?RIIa, as they inhibited only immune complex-induced responses and had no effect on responses to stimuli unrelated to FcR, for example platelet stimulation with arachidonic acid. In vivo testing of the SCE in Fc?RIIa transgenic mice showed that they inhibited the development and stopped the progression of collagen-induced arthritis (CIA). The SCEs were more potent than methotrexate and anti-CD3 in sustained suppression of CIA. Thus, in vitro and in vivo activity of these SCE Fc?RIIa receptor antagonists demonstrated their potential as anti-inflammatory agents for autoimmune diseases involving immune complexes. © 2009 Australasian Society for Immunology Inc. All rights reserved
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