160 research outputs found

    Bio-inspired Tensegrity Soft Modular Robots

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    In this paper, we introduce a design principle to develop novel soft modular robots based on tensegrity structures and inspired by the cytoskeleton of living cells. We describe a novel strategy to realize tensegrity structures using planar manufacturing techniques, such as 3D printing. We use this strategy to develop icosahedron tensegrity structures with programmable variable stiffness that can deform in a three-dimensional space. We also describe a tendon-driven contraction mechanism to actively control the deformation of the tensegrity mod-ules. Finally, we validate the approach in a modular locomotory worm as a proof of concept.Comment: 12 pages, 7 figures, submitted to Living Machine conference 201

    Portosystemic collateral vessels in liver cirrhosis: a three-dimensional MDCT pictorial review

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    PURPOSE: Portosystemic collateral vessels (PSCV) are a consequence of the portal hypertension that occurs in chronic liver diseases. Their prognosis is strongly marked by the risk of digestive hemorrhage and hepatic encephalopathy. MATERIALS AND METHODS: CT was performed with a 16-MDCT scanner. Maximum intensity projection and volume rendering were systematically performed on a workstation to analyze PSCV. RESULTS: We describe the PSCV according to their drainage into either the superior or the inferior vena cava. In the superior vena cave group, we found gastric veins, gastric varices, esophageal, and para-esophageal varices. In the inferior vena cava group, the possible PSCV are numerous, with different sub groups: gastro and spleno renal shunts, paraumbilical and abdominal wall veins, retroperitoneal shunts, mesenteric varices, gallbladder varices, and omental collateral vessels. Regarding clinical consequences esophageal and gastric varices are most frequently involved in digestive bleeding; splenorenal shunts often lead to hepatic encephalopathy; the paraumbilical vein is an acceptable derivation pathway for natural decompression of the portal system. CONCLUSION: Knowledge of precise cartography of PSCV is essential to therapeutic decisions. MDCT is the best way to understand and describe the different types of PSCV

    Amyloid-ÎČ reduces the expression of neuronal FAIM-L, thereby shifting the inflammatory response mediated by TNFα from neuronal protection to death

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    The brains of patients with Alzheimer’s disease (AD) present elevated levels of tumor necrosis factor-α (TNFα), a cytokine that has a dual function in neuronal cells. On one hand, TNFα can activate neuronal apoptosis, and on the other hand, it can protect these cells against amyloid-ÎČ (AÎČ) toxicity. Given the dual behavior of this molecule, there is some controversy regarding its contribution to the pathogenesis of AD. Here we examined the relevance of the long form of Fas apoptotic inhibitory molecule (FAIM) protein, FAIM-L, in regulating the dual function of TNFα. We detected that FAIM-L was reduced in the hippocampi of patients with AD. We also observed that the entorhinal and hippocampal cortex of a mouse model of AD (PS1M146LxAPP751sl) showed a reduction in this protein before the onset of neurodegeneration. Notably, cultured neurons treated with the cortical soluble fractions of these animals showed a decrease in endogenous FAIM-L, an effect that is mimicked by the treatment with AÎČ-derived diffusible ligands (ADDLs). The reduction in the expression of FAIM-L is associated with the progression of the neurodegeneration by changing the inflammatory response mediated by TNFα in neurons. In this sense, we also demonstrate that the protection afforded by TNFα against AÎČ toxicity ceases when endogenous FAIM-L is reduced by short hairpin RNA (shRNA) or by treatment with ADDLs. All together, these results support the notion that levels of FAIM-L contribute to determine the protective or deleterious effect of TNFα in neuronal cells

    X-linked Inhibitor of Apoptosis Protein negatively regulates neuronal differentiation through interaction with cRAF and Trk

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    Altres ajuts: CIBERNED CB06/05/0042 i CB06/05/1104, RENEVAS RD06/0026/1009 i Juan de la CiervaX-linked Inhibitor of apoptosis protein (XIAP) has been classically identified as a cell death regulator. Here, we demonstrate a novel function of XIAP as a regulator of neurite outgrowth in neuronal cells. In PC12 cells, XIAP overexpression prevents NGF-induced neuronal differentiation, whereas NGF treatment induces a reduction of endogenous XIAP levels concomitant with the induction of neuronal differentiation. Accordingly, downregulation of endogenous XIAP protein levels strongly increases neurite outgrowth in PC12 cells as well as axonal and dendritic length in primary cortical neurons. The effects of XIAP are mediated by the mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinases (ERKs) pathway since blocking this pathway completely prevents the neuritogenesis mediated by XIAP downregulation. In addition, we found that XIAP binds to cRaf and Trk receptors. Our results demonstrate that XIAP plays a new role as a negative regulator of neurotrophin-induced neurite outgrowth and neuronal differentiation in developing neurons

    Lumos: a statewide linkage programme in Australia integrating general practice data to guide system redesign

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    ObjectiveWith ageing of the Australian population, more people are living longer and experiencing chronic or complex health conditions. The challenge is to have information that supports the integration of services across the continuum of settings and providers, to deliver person-centred, seamless, efficient and effective healthcare. However, in Australia, data are typically siloed within health settings, precluding a comprehensive view of patient journeys. Here, we describe the establishment of the Lumos programme—the first statewide linked data asset across primary care and other settings in Australia and evaluate its representativeness to the census population.Methods and analysisRecords extracted from general practices throughout New South Wales (NSW), Australia’s most populous state, were linked to patient records from acute and other settings. Innovative privacy and security technologies were employed to facilitate ongoing and regular updates. The marginal demographic distributions of the Lumos cohort were compared with the NSW census population by calculating multiple measures of representation to evaluate its generalisability.ResultsThe first Lumos programme data extraction linked 1.3 million patients’ general practice records to other NSW health system data. This represented 16% of the NSW population. The demographic distribution of patients in Lumos was &gt;95% aligned to that of the NSW population in the calculated measures of representativeness.ConclusionThe Lumos programme delivers an enduring, regularly updated data resource, providing unique insights about statewide, cross-setting healthcare utilisation. General practice patients represented in the Lumos data asset are representative of the NSW population overall. Lumos data can reliably be used to identify at-risk regions and groups, to guide the planning and design of health services and to monitor their impact throughout NSW.</jats:sec

    the world wide randomized antibiotic envelope infection prevention wrap it trial long term follow up

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    Abstract Background The WRAP-IT trial reported a 40% reduction in major CIED infection within 12 months of the procedure with the antibacterial-eluting envelope (TYRX). Objective This report describes the longer-term (>12 months) envelope effects on infection reduction and complications. Methods All trial patients that underwent CIED replacement, upgrade, revision, or initial CRT-D implant received standard-of-care infection prophylaxis and were randomized 1:1 to receive the envelope or not. CIED infection incidence, and procedure and system-related complications were characterized through all follow-up (36 months) using Cox proportional hazard regression modeling. Results In total, 6800 patients received their intended randomized treatment (3371 envelope; 3429 control; mean follow-up 21.0±8.3 months). Major CIED-related infection occurred in 32 envelope patients and 51 control patients (KM estimate, 1.3% vs. 1.9%; HR: 0.64, 95% CI: 0.41-0.99; P=0.046). Any CIED-related infection occurred in 57 envelope patients and 84 control patients (KM estimate, 2.1% vs. 2.8%; HR: 0.69, 95% CI: 0.49-0.97; P=0.030). System- or procedure-related complications occurred in 235 envelope patients and 252 control patients (KM estimate, 8.0% vs. 8.2%; HR, 0.95, 95% CI: 0.79-1.13; P Conclusions The effects of the TYRX envelope in reducing the risk of CIED infection are sustained beyond the first year post-procedure, without increased risk of complication

    Involvement of VDAC, Bax and Ceramides in the Efflux of AIF from Mitochondria during Curcumin-Induced Apoptosis

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    Contains fulltext : 80085.pdf (publisher's version ) (Open Access)BACKGROUND: We previously identified curcumin as a potent inducer of fibroblast apoptosis, which could be used to treat hypertrophic scar formation. Here we investigated the underlying mechanism of this process. PRINCIPAL FINDINGS: Curcumin-induced apoptosis could not be blocked by caspase-inhibitors and we could not detect any caspase-3/7 activity. Curcumin predominantly induced mitochondria-mediated ROS formation and stimulated the expression of the redox-sensitive pro-apoptotic factor p53. Inhibition of the pro-apoptotic signaling enzyme glycogen synthase kinase-3beta (GSK-3beta) blocked curcumin-induced apoptosis. Apoptosis was associated with high molecular weight DNA damage, a possible indicator of apoptosis-inducing factor (AIF) activity. Indeed, curcumin caused nuclear translocation of AIF, which could be blocked by the antioxidant N-acetyl cysteine. We next investigated how AIF is effluxed from mitochondria in more detail. The permeability transition pore complex (PTPC), of which the voltage-dependent anion channel (VDAC) is a component, could be involved since the VDAC-inhibitor DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid) efficiently blocked AIF translocation. However, PTPC is not involved in AIF release since cyclosporine A, a specific inhibitor of the complex did not block apoptosis. Alternatively, the pro-apoptotic protein Bax could have formed mitochondrial channels and interacted with VDAC. Curcumin caused mitochondrial translocation of Bax, which was blocked by DIDS, suggesting a Bax-VDAC interaction. Interestingly, ceramide channels can also release apoptogenic factors from mitochondria and we found that addition of ceramide induced caspase-independent apoptosis. Surprisingly, this process could also be blocked by DIDS, suggesting the concerted action of Bax, VDAC and ceramide in the efflux of AIF from the mitochondrion. CONCLUSIONS: Curcumin-induced fibroblast apoptosis is totally caspase-independent and relies on the mitochondrial formation of ROS and the subsequent nuclear translocation of AIF, which is released from a mitochondrial pore that involves VDAC, Bax and possibly ceramides. The composition of the AIF-releasing channel seems to be much more complex than previously thought
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