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Showing 901–920 of 2058 publications.
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Yeo, Giselle C.; Tarakanova, Anna; Baldock, Clair; Wise, Steven G.; Buehler, Markus J.; Weiss, Anthony StevenThe assembly of the tropoelastin monomer into elastin is vital for conferring elasticity on blood vessels, skin, and lungs. Tropoelastin has dual needs for flexibility and structure in self-assembly. We explore the structuredynamics-function interplay, consider the duality of molecular order and disorder, and identify equally significant functional contributions by local and global structures. To study these organizational stratifications, we perturb a key hinge region by expressing an exon that is universally spliced out in human tropoelastins. We find a herniated nanostructure with a displaced C terminus and explain by molecular modeling that flexible helices are replaced with substantial b sheets. We see atypical higher-order cross-linking and inefficient assembly into discontinuous, thick elastic fibers. We explain this dysfunction by correlating local and global structural effects with changes in the molecule's assembly dynamics. This work has general implications for our understanding of elastomeric proteins, which balance disordered regions with defined structural modules at multiple scales for functional assembly. 2018 The Authors.
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Samson, Andre L.; Ho, Bosco K.; Au, Amanda E.; Schoenwaelder, Simone M.; Smyth, Mark J.; Bottomley, Stephen P.; Kleifeld, Oded; Medcalf, Robert LindsayAmyloidogenic protein aggregation impairs cell function and is a hallmark of many chronic degenerative disorders. Protein aggregation is also a major event during acute injury; however, unlike amyloidogenesis, the process of injuryinduced protein aggregation remains largely undefined. To provide this insight, we profiled the insoluble proteome of several cell types after acute injury. These experiments show that the disulfide-driven process of nucleocytoplasmic coagulation (NCC) is the main form of injury-induced protein aggregation. NCC is mechanistically distinct from amyloidogenesis, but still broadly impairs cell function by promoting the aggregation of hundreds of abundant and essential intracellular proteins. A small proportion of the intracellular proteome resists NCC and is instead released from necrotic cells. Notably, the physicochemical properties of NCC-resistant proteins are contrary to those of NCC-sensitive proteins. These observations challenge the dogma that liberation of constituents during necrosis is anarchic. Rather, inherent physicochemical features including cysteine content, hydrophobicity and intrinsic disorder determine whether a protein is released from necrotic cells. Furthermore, as half of the identified NCC-resistant proteins are known autoantigens, we propose that physicochemical properties that control NCC also affect immune tolerance and other host responses important for the restoration of homeostasis after necrotic injury. 2016 The Authors.
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Martinez, Carlos; Suissa, Samy; Rietbrock, Stephan; Katholing, Anja; Freedman, Ben Ben; Cohen, Alexander Thomas; Handelsman, David J.Objective: To determine the risk of venous thromboembolism associated with use of testosterone treatment in men, focusing particularly on the timing of the risk. Design: Population based case-control study. Setting: 370 general practices in UK primary care with linked hospital discharge diagnoses and in-hospital procedures and information on all cause mortality. Participants: 19 215 patients with confirmed venous thromboembolism (comprising deep venous thrombosis and pulmonary embolism) and 909 530 age matched controls from source population including more than 2.22 million men between January 2001 and May 2013. Exposure of interest: Three mutually exclusive testosterone exposure groups were identified: current treatment, recent (but not current) treatment, and no treatment in the previous two years. Current treatment was subdivided into duration of more or less than six months. Main outcom e measure: Rate ratios of venous thromboembolism in association with current testosterone treatment compared with no treatment were estimated using conditional logistic regression and adjusted for comorbidities and all matching factors. Results: The adjusted rate ratio of venous thromboembolism was 1.25 (95% confidence interval 0.94 to 1.66) for current versus no testosterone treatment. In the first six months of testosterone treatment, the rate ratio of venous thromboembolism was 1.63 (1.12 to 2.37), corresponding to 10.0 (1.9 to 21.6) additional venous thromboembolisms above the base rate of 15.8 per 10 000 person years. The rate ratio after more than six months' treatment was 1.00 (0.68 to 1.47), and after treatment cessation it was 0.68 (0.43 to 1.07). Increased rate ratios within the first six months of treatment were observed in all strata: the rate ratio was 1.52 (0.94 to 2.46) for patients with pathological hypogonadism and 1.88 (1.02 to 3.45) for those without it, and 1.41 (0.82 to 2.41) for those with a known risk factor for venous thromboembolism and 1.91 (1.13 to 3.23) for those without one. Conclusions: Starting testosterone treatment was associated with an increased risk of venous thromboembolism, which peaked within six months and declined thereafter. 2016 BMJ Publishing Group Limited.
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Robertson, Stacy; Martez, Gonzalo J.; Payet, Cloe A.; Barraclough, Jennifer Y.; Celermajer, David S.; Bursill, C. A.; Patel, SanjayInflammasome activation, with subsequent release of pro-inflammatory cytokines interleukin-1? (IL-1?) and IL-18, has recently been implicated in atherosclerosis-associated inflammation. This study aims to assess in acute coronary syndrome (ACS) patients (1) inflammasome activation in circulating monocytes and (2) whether short-term oral colchicine, a recognized anti-inflammatory agent that has been shown to be cardio-protective in clinical studies, might acutely suppress inflammasome-dependent inflammation. ACS patients (n = 21) were randomized to oral colchicine (1 mg followed by 0.5 mg 1 h later) or no treatment, and compared with untreated healthy controls (n = 9). Peripheral venous blood was sampled pre- (day 1) and 24 h post- (day 2) treatment. Monocytes were cultured and stimulated with ATP. Analysis of key inflammasome markers was performed by ELISA. IL-1? secretion increased by 580.4% (P<0.01) in ACS patients compared with controls but only with ATP stimulation. Untreated ACS patients secreted significantly higher levels of IL-18 compared with healthy controls independent of ATP stimulation (P<0.05). Colchicine treatment in ACS patients markedly reduced intracellular and secreted levels of IL-1? compared with pre-treatment levels (P<0.05 for both), as well as significantly reducing pro-caspase-1 mRNA levels by 57.7% and secreted caspase-1 protein levels by 30.2% compared with untreated patients (P<0.05 for both). Monocytes from ACS patients are 'primed' to secrete inflammasome-related cytokines and short-term colchicine acutely and markedly suppresses monocyte caspase-1 activity, thereby reducing monocyte secretion of IL-1?. 2016 The Author(s).
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Griffiths, Kristi R.; Grieve, Stuart M.; Kohn, Michael R.; Clarke, Simon D.; Williams, Leanne M.; Korgaonkar, Mayuresh S.Although multiple studies have reported structural deficits in multiple brain regions in attention-deficit hyperactivity disorder (ADHD), we do not yet know if these deficits reflect a more systematic disruption to the anatomical organization of large-scale brain networks. Here we used a graph theoretical approach to quantify anatomical organization in children and adolescents with ADHD. We generated anatomical networks based on covariance of gray matter volumes from 92 regions across the brain in children and adolescents with ADHD (n = 34) and age-and sex-matched healthy controls (n = 28). Using graph theory, we computed metrics that characterize both the global organization of anatomical networks (interconnectivity (clustering), integration (path length) and balance of global integration and localized segregation (small-worldness)) and their local nodal measures (participation (degree) and interaction (betweenness) within a network). Relative to Controls, ADHD participants exhibited altered global organization reflected in more clustering or network segregation. Locally, nodal degree and betweenness were increased in the subcortical amygdalae in ADHD, but reduced in cortical nodes in the anterior cingulate, posterior cingulate, mid temporal pole and rolandic operculum. In ADHD, anatomical networks were disrupted and reflected an emphasis on subcortical local connections centered around the amygdala, at the expense of cortical organization. Brains of children and adolescents with ADHD may be anatomically configured to respond impulsively to the automatic significance of stimulus input without having the neural organization to regulate and inhibit these responses. These findings provide a novel addition to our current understanding of the ADHD connectome. The Author(s) 2016.
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Lam, Yuen TingReactive oxygen species (ROS) regulate bone marrow microenvironment for stem and progenitor cells functions including self-renewal, differentiation, and cell senescence. In response to ischemia, ROS also play a critical role in mediating the mobilization of endothelial progenitor cells (EPCs) from the bone marrow to the sites of ischemic injury, which contributes to postnatal neovascularization. Aging is an unavoidable biological deteriorative process with a progressive decline in physiological functions. It is associated with increased oxidative stress and impaired ischemia-induced neovascularization. This review discusses the roles of ROS in regulating stem and progenitor cell function, highlighting the impact of unbalanced ROS levels on EPC dysfunction and the association with age-related impairment in ischemia-induced neovascularization. Furthermore, it discusses strategies that modulate the oxidative levels of stem and progenitor cells to enhance the therapeutic potential for elderly patients with cardiovascular disease. 2016 Yuen Ting Lam.
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Bhandare, Amol M.; Kapoor, Komal; Pilowsky, Paul M.; Farnham, M. M. J.Cardiovascular autonomic dysfunction in seizure is a major cause of sudden unexpected death in epilepsy. The catecholaminergic neurons in the rostral ventrolateral medulla (RVLM) maintain sympathetic vasomotor tone and blood pressure through their direct excitatory projections to the intermediolateral (IML) cell column. Glutamate, the principal excitatory neurotransmitter in brain, is increased in seizures. Pituitary adenylate cyclase activating polypeptide (PACAP) is an excitatory neuropeptide with neuroprotective properties, whereas microglia are key players in inflammatory responses in CNS. We investigated the roles of glutamate, PACAP, and microglia on RVLM catecholaminergic neurons during the cardiovascular responses to 2 mg/kg kainic acid (KA)-induced seizures in urethane anesthetized, male Sprague Dawley rats. Microinjection of the glutamate antagonist, kynurenic acid (50 nl; 100 mM) into RVLM, blocked the seizure-induced 43.2 12.6% sympathoexcitation (p ? 0.05), and abolished the pressor responses, tachycardia, and QT interval prolongation. PACAP or microglia antagonists (50 nl) (PACAP(638), 15 pmol; minocycline 10 mg/ml) microinjected bilaterally into RVLM had no effect on seizure-induced sympathoexcitation, pressor responses, or tachycardia but abolished the prolongation of QT interval. The actions of PACAP or microglia on RVLM neurons do not cause sympathoexcitation, but they do elicit proarrhythmogenic changes. An immunohistochemical analysis in 2 and 10 mg/kg KA-induced seizure rats revealed that microglia surrounding catecholaminergic neurons are in a surveillance state with no change in the number of M2 microglia (anti-inflammatory). In conclusion, seizure-induced sympathoexcitation is caused by activation of glutamatergic receptors in RVLM that also cause proarrhythmogenic changes mediated by PACAP and microglia. 2016 the authors.
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Morris, Gary P.; Wright, Amanda L.; Tan, Richard P.; Gladbach, Amadeus; Ittner, Lars Matthias; Vissel, BryceThe intraluminal filament model of middle cerebral artery occlusion (MCAO) in mice and rats has been plagued by inconsistency, owing in part to the multitude of variables requiring control. In this study we investigated the impact of several major variables on survival rate, lesion volume, neurological scores, cerebral blood flow (CBF) and body weight including filament width, time after reperfusion, occlusion time and the choice of surgical method. Using the Koizumi method, we found ischemic injury can be detected as early as 30 min after reperfusion, to a degree that is not statistically different from 24 h post-perfusion, using 2,3,5-Triphenyltetrazolium chloride (TTC) staining.We also found a distinct increase in total lesion volume with increasing occlusion time, with 30-45 min a critical time for the development of large, reproducible lesions. Furthermore, although we found no significant difference in total lesion volume generated by the Koizumi and Longa methods of MCAO, nor were survival rates appreciably different between the two at 4 h after reperfusion, the Longa method produces significantly greater reperfusion. Finally, we found no statistical evidence to support the exclusion of data from animals experiencing a CBF reduction of <70% in the MCA territory following MCAO, using laser-Doppler flowmetry. Instead we suggest the main usefulness of laser-Doppler flowmetry is for guiding filament placement and the identification of subarachnoid haemorrhages and premature reperfusion. In summary, this study provides detailed evaluation of the Koizumi method of intraluminal filament MCAO in mice and a direct comparison to the Longa method.
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Callaghan, Fraser Maurice; Kozor, Rebecca A.; Sherrah, Andrew G.; Vallely, Michael P.; Celermajer, David S.; Figtree, Gemma A.; Grieve, Stuart M.Purpose To show that the use of a multi-velocity encoding (VENC) 4D-flow approach offers significant improvements in the characterization of complex flow in the aorta. Four-dimensional flow magnetic resonance imaging (MRI) (4D-flow) can be used to measure complex flow patterns and dynamics in the heart and major vessels. The quality of the information derived from these measures is dependent on the accuracy of the vector field, which is limited by the vector-to-noise ratio. Materials and Methods A 4D-flow protocol involving three different VENC values of 150, 60, and 20 cm/s was performed on six control subjects and nine patients with type-B chronic aortic dissection at 3T MRI. Data were processed using a single VENC value (150 cm/s) or using a fused dataset that selected the lowest appropriate VENC for each voxel. Performance was analyzed by measuring spatial vector angular correlation, magnitude correlation, temporal vector conservation, and "real-world" streamline tracing performance. Results The multi-VENC approach provided a 31% improvement in spatial and 53% improvement in temporal precision of velocity vector measurements during the mid-late diastolic period, where 99% of the flow vectors in the normal aorta are below 20 cm/s. In low-flow conditions this resulted in practical improvements of greater than 50% in pathline tracking and streamline tracing quantified by streamline curvature measurements. Conclusion A multi-VENC 4D-flow approach provides accurate vector data across normal physiological velocities observed in the aorta, dramatically improving outputs such as pathline tracking, streamline estimation, and further advanced analyses.J. Magn. Reson. Imaging 2016;43:352-363. 2015 Wiley Periodicals, Inc.
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Galougahi, Keyvan Karimi; Liu, Chiachi; Garcia, Alvaro; Gentile, Carmine; Fry, Natasha Alexandria Sarah; Hamilton, Elisha J.; Hawkins, Clare L.; Figtree, Gemma A.Background--Perturbed balance between NO and O<inf>2</inf> .-. (ie, NO/redox imbalance) is central in the pathobiology of diabetesinduced vascular dysfunction. We examined whether stimulation of ?<inf>3</inf> adrenergic receptors (?<inf>3</inf> ARs), coupled to endothelial nitric oxide synthase (eNOS) activation, would re-establish NO/redox balance, relieve oxidative inhibition of the membrane proteins eNOS and Na+-K+ (NK) pump, and improve vascular function in a new animal model of hyperglycemia. Methods and Results--We established hyperglycemia in male White New Zealand rabbits by infusion of S961, a competitive highaffinity peptide inhibitor of the insulin receptor. Hyperglycemia impaired endothelium-dependent vasorelaxation by "uncoupling" of eNOS via glutathionylation (eNOS-GSS) that was dependent on NADPH oxidase activity. Accordingly, NO levels were lower while O<inf>2</inf> .- levels were higher in hyperglycemic rabbits. Infusion of the ?<inf>3</inf> AR agonist CL316243 (CL) decreased eNOS-GSS, reduced O<inf>2</inf> .-, restored NO levels, and improved endothelium-dependent relaxation. CL decreased hyperglycemia-induced NADPH oxidase activation as suggested by co-immunoprecipitation experiments, and it increased eNOS co-immunoprecipitation with glutaredoxin-1, which may reflect promotion of eNOS de-glutathionylation by CL. Moreover, CL reversed hyperglycemia-induced glutathionylation of the ?<inf>1</inf> NK pump subunit that causes NK pump inhibition, and improved K+-induced vasorelaxation that reflects enhancement in NK pump activity. Lastly, eNOS-GSS was higher in vessels of diabetic patients and was reduced by CL, suggesting potential significance of the experimental findings in human diabetes. Conclusions-?<inf>3</inf> AR activation restored NO/redox balance and improved endothelial function in hyperglycemia. ?<inf>3</inf> AR agonists may confer protection against diabetes-induced vascular dysfunction. 2016 The Authors.
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Seneviratne, Martin G.; Grieve, Stuart M.; Figtree, Gemma A.; Garsia, Roger J.; Celermajer, David S.; Adelstein, Stephen A.; Puranik, RajeshObjectives To assess the prevalence, distribution and clinical correlates of myocardial fibrosis, as detected by cardiac magnetic resonance (CMR), in systemic lupus erythematosus (SLE). Methods Forty-one subjects (average age 39 12 years and 80% female) with SLE underwent CMR imaging at 1.5T, using late gadolinium enhancement (LGE) to quantify the area of myocardial fibrosis in the left ventricle (LV). Subjects also underwent transthoracic echocardiography (TTE) and exercise testing. Results LGE was detected in 15/41 subjects, 11 with localized LGE (<15% LV mass) and four with extensive LGE (>15% LV mass). The commonest site of LGE was the interventricular septum, with all but one case demonstrating an intramural or inflammatory pattern. The mean age of the >15% LGE group (55 15 years) was significantly higher than the <15% or absent LGE subgroups. Based on both CMR and TTE measurements, subjects with LGE > 15% demonstrated a reduced E/A ratio of 0.9 0.4 relative to the <15% and absent LGE subgroups. LV end-systolic volume (ESVi), end-diastolic volume (EDVi) and maximum exercise capacity were also reduced in the >15% LGE group. Conclusions Mid-wall myocardial fibrosis occurs frequently in SLE and is strongly associated with advancing subject age, but not with SLE duration or severity. Extensive LGE may be associated with diastolic dysfunction and impaired exercise capacity, although this may be an epiphenomenon of age. Cardiac magnetic resonance with quantitative assessment of LGE may provide a basis for cardiac risk stratification in SLE. SAGE Publications.
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Puranik, Rajesh; Bao, Shishan San; Bonin, Antonio M.; Kaur, Ravinder; Weder, Jane E.; Casbolt, Llewellyn S.; Hambley, Trevor W.; Lay, Peter Andrew; Barter, Philip J.; Rye, Kerry AnneBackground: The ability of Zn(II) and Cu(II) metal complexes of non-steroidal anti-inflammatory drugs (NSAIDs) to inhibit acute arterial inflammation in vivo has been studied. Results: When acute vascular inflammation was induced in normocholesterolemic New Zealand White rabbits by inserting a non-occlusive silastic collar around the common carotid artery, a single oral dose of Cu(II)-indomethacin (Cu(II)Indo, 3 mg/kg) administered by laparotomy achieved a 67 % (8.2 1.7 vs. 2.7 0.4 image units, p < 0.05) reduction in endothelial expression of vascular cell adhesion molecule-1 (VCAM-1) but did not inhibit endothelial intercellular adhesion molecule (ICAM-1) expression significantly. Treatment with Cu(II)-acemetacin (Cu(II)ACM, 3 mg/kg) led to a profound 88 % (8.2 1.7 vs. 1.0 0.5 image units, p < 0.01) reduction in endothelial VCAM-1 expression but did not inhibit ICAM-1 expression, while treatment with Zn(II)-acemetacin (Zn(II)ACM, 3 mg/kg) led to an 84 % (19.3 1.0 vs. 3.1 1.2 image units, p < 0.01) reduction in endothelial ICAM-1 expression and did not inhibit VCAM-1 expression. No adverse gastric, hepatic or renal effects were observed in treated animals. Conclusion: These findings provide the "proof of concept" that this novel class of drug, where there is complexation of NSAIDs with metal ions, has substantial anti-inflammatory effects in an animal model of acute vascular inflammation with the possibility of low rates of adverse effects. 2016 Puranik et al.
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Wise, Steven G.; Liu, Hongjuan; Yeo, Giselle C.; Michael, Praveesuda Lorwattanapongsa; Chan, Alex H.P.; Ngo, Alan K.Y.; Bilek, Marcela M.M.; Bao, Shishan San; Weiss, Anthony StevenPolyurethanes are versatile elastomers but suffer from biological limitations such as poor control over cell attachment and the associated disadvantages of increased fibrosis. We address this problem by presenting a novel strategy that retains elasticity while modulating biological performance. We describe a new biomaterial that comprises a blend of synthetic and natural elastomers: the biostable polyurethane Elast-Eon and the recombinant human tropoelastin protein. We demonstrate that the hybrid constructs yield a class of coblended elastomers with unique physical properties. Hybrid constructs displayed higher elasticity and linear stress-strain responses over more than threefold strain. The hybrid materials showed increased overall porosity and swelling in comparison to polyurethane alone, facilitating enhanced cellular interactions. In vitro, human dermal fibroblasts showed enhanced proliferation, while in vivo, following subcutaneous implantation in mice, hybrid scaffolds displayed a reduced fibrotic response and tunable degradation rate. To our knowledge, this is the first example of a blend of synthetic and natural elastomers and is a promising approach for generating tailored bioactive scaffolds for tissue repair. Copyright 2016, Mary Ann Liebert, Inc. 2016.
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Arnott, Clare; Punnia-Moorthy, Gaya; Tan, Joanne Tsui Ming; Sadeghipour, Sara; Bursill, C. A.; Patel, SanjayIntroduction Recent studies have suggested that the VEGF inhibitors, Ranibizumab and Aflibercept may be associated with an excess of cardiovascular events, potentially driven by increasing atheroma instability, leading to plaque rupture and clinical events. Inflammation plays a key role in the progression of atherosclerotic plaque and particularly conversion to an unstable phenotype. Here, we sought to assess the in vitro effects of these drugs on the expression of key inflammatory mediators on endothelial cells. Methods Human coronary artery endothelial cells were coincubated for 16h with Ranibizumab (0.11nM) or Aflibercept (0.45nM), as determined by each drug's peak serum concentration (Cmax). Expression at protein (ELISA) and gene (RTPCR) level of inflammatory chemokines CCL2, CCL5 and CXC3L1 as well as gene expression for the cell adhesion molecules VCAM1, ICAM1 and the key NF?b protein p65 was assessed. VEGFA protein levels were also determined. Results Both drugs significantly increased chemokine, cell adhesion molecule (CAM) and p65 expression, while decreasing VEGFA protein secretion. At equivalent Cmax concentrations, Aflibercept was significantly more proinflammatory than Ranibizumab. Reduction of secreted VEGFA levels significantly attenuated inflammatory effects of both drugs, whereas blockade of the VEGFA receptor or silencing of VEGFA gene synthesis alone had no effect, suggesting that binding of drug to secreted VEGFA is crucial in promoting inflammation. Finally, blockade of Tolllike receptor 4 significantly reduced inflammatory effects of both drugs. Conclusion We demonstrated here, for the first time, that both drugs have potent proinflammatory effects, mediated via activation of Tolllike receptor 4 on the endothelial cell surface by drug bound to VEGFA. Further studies are required to investigate whether these effects are also seen in vivo. 2016 Arnott et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Thompson, Peter Lindsay; Morton, Allison C.Coronary heart disease (CHD) and atrial ibrillation (AF) commonly occur together. This presents challenges for the clinician treating patients with cHd, who require antiplatelet therapy and patients with aF, who require oral anticoagulant therapy. We have reviewed Pubmed and ScOPUS to identify relevant guidelines, randomised clinical trials and registry studies and clinical trials presented at international meetings, and where necessary, clinical trial protocols to identify and critically analyze all relevant trials in which combinations of oral anticoagulants and antiplatelet agents in patients with AF and CHD have been evaluated. The available evidence on the eficacy and safety of combined oral anticoagulants and anti platelet agents was reviewed for the aF patient in three clinical scenarios: 1) after percutaneous coronary intervention (Pci); 2) after an acute coronary syndrome without Pci; and 3) in stable cHd. in each the clinical scenarios evaluated, there is limited clinical trial evidence to guide clinical management. Guidelines to help the clinician choose the right combinations of warfarin, clopidogrel and aspirin and the duration of treatment have been published, but they are based on a limited evidence base. There is even less evidence to guide the use of new oral anticoagulants (NOacs) in combination with the new P2Y12 antiplatelet agents. in each clinical scenario, the risks of coronary artery or stent thrombosis in cHd and risks of stroke in aF need to be carefully balanced against the risks of bleeding. We make recommendations for management based on the evidence which is available at this time and indicate the many gaps which are currently being addressed by randomized clinical trials. 2016 EDIZIONI MINERVA MEDICA.
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Nedoboy, Polina E.; Mohammed, Suja; Kapoor, Komal; Bhandare, Amol M.; Farnham, M. M. J.; Pilowsky, Paul M.Identification of neurons, and their phenotype, that are activated in response to specific stimuli is a critical step in understanding how neural networks integrate inputs to produce specific outputs. Here, we developed novel mouse monoclonal antibodies of different IgG isotypes that are specific to tyrosine hydroxylase (TH), and to tyrosine hydroxylase activated at its serine 40 position (pSer40TH), in order to assess changes in the activity of phenotypically identified cardiovascular neurons using fluorescence immunohistochemistry. We find that the proportion of C1 pSer40TH-positive neurons in the central and medial region of the rat rostral ventrolateral medulla (RVLM) increases dramatically following hydralazine treatment, whereas phenylephrine treatment does not significantly change the pSer40TH/TH ratio in these regions compared to control. This finding suggests that there is a mediolateral topology associated with the activation of C1 neurons following baroreceptor loading or unloading. Overall, we conclude first, that our newly characterized monoclonal antibodies are specific, and selective, against TH and pSer40TH. Secondly, that they can be used to label TH and pSer40TH immunoreactive neurons simultaneously, and thirdly that that they can be used to identify the activation state of catecholamine synthetizing neurons after physiological stimuli. Finally, we find that there is basal level of activation of TH neurons in the lateral, central and medial regions (~70%, 30% and 45%, respectively) of the C1 area, but that following unloading of the baroreceptors there is a marked increase in activation of central (~80%) and medial (~90%) C1 neurons in the RVLM. 2016 Elsevier Ltd.
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Lip, Gregory Y.H.; Fauchier, Laurent; Freedman, Ben Ben; van Gelder, Isabelle C.; Natale, Andrea; Gianni, Carola; Nattel, Stanley; Potpara, Tatjana S.; Rienstra, Michiel; Tse, Hung Fat; Lane, Deirdre A.Atrial fibrillation (AF) is the most common sustained cardiac rhythm disorder, and increases in prevalence with increasing age and the number of cardiovascular comorbidities. AF is characterized by a rapid and irregular heartbeat that can be asymptomatic or lead to symptoms such as palpitations, dyspnoea and dizziness. The condition can also be associated with serious complications, including an increased risk of stroke. Important recent developments in the clinical epidemiology and management of AF have informed our approach to this arrhythmia. This Primer provides a comprehensive overview of AF, including its epidemiology, mechanisms and pathophysiology, diagnosis, screening, prevention and management. Management strategies, including stroke prevention, rate control and rhythm control, are considered. We also address quality of life issues and provide an outlook on future developments and ongoing clinical trials in managing this common arrhythmia. 2016 Macmillan Publishers Limited.
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Majima, Hideyuki J.; Indo, Hiroko P.; Nakanishi, Ikuo; Suenaga, Shigeaki; Matsumoto, Kenichiro; Matsui, Hirofumi; Minamiyama, Yukiko; Ichikawa, Hiroshi; Yen, Hsiuchuan; Hawkins, Clare L.; Davies, Michael J.; Ozawa, Tosfiihiko; St. Clair, Daret K.Prof. Dr. Helmut Sies is a pioneer of "Oxidative Stress", and has published over 18 papers with the name of "Oxidative Stress" in the title. He has been Editor-in-Chief of the journal "Archives of Biochemistry and Biophysics" for many years, and is a former Editor-in-Chief of the journal "Free Radical Research". He has clarified our understanding of the causes of chronic developing diseases, and has studied antioxidant factors. In this article, importance of "Oxidative Stress" and our mitochondrial oxidative stress studies; roles of mitochondrial ROS, effects of vitamin E and its homologues in oxidative stress-related diseases, effects of antioxidants in vivo and in vitro, and a mitochondrial superoxide theory for oxidative stress diseases and aging are introduced, and some of our interactions with Helmut are described, congratulating and appreciating his great path. 2015 Elsevier Inc. All rights reserved.
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Yeo, Giselle C.; Santos, Miguel; Kondyurin, Alexey V.; Likov Jana; Weiss, Anthony Steven; Bilek, Marcela M.M.The mechanical strength, durability, corrosion resistance, and biocompatibility of metal alloys based on zirconium (Zr) and titanium (Ti) make them desirable materials for orthopedic implants. However, as bioinert metals, they do not actively promote bone formation and integration. Here we report a plasma coating process for improving integration of such metal implants with local bone tissue. The coating is a stable carbon-based plasma polymer layer that increased surface wettability by 28%, improved surface elasticity to the range exhibited by natural bone, and additionally covalently bound the extracellular matrix protein, tropoelastin, in an active conformation. The thus biofunctionalized material was significantly more resistant to medical-grade sterilization by steam, autoclaving or gamma-ray irradiation, retaining >60% of the adhered tropoelastin molecules and preserving full bioactivity. The interface of the coating and metal was robust so as to resist delamination during surgical insertion and in vivo deployment, and the plasma process employed was utilized to also coat the complex 3D geometries typical of orthopedic implants. Osteoblast-like osteosarcoma cells cultured on the biofunctionalized Zr surface exhibited a significant 30% increase in adhesion and up to 70% improvement in proliferation. Cells on these materials also showed significant early stage up-regulation of bone marker expression (alkaline phosphatase, 1.8 fold; osteocalcin, 1.4 fold), and sustained up-regulation of these genes (alkaline phosphatase, 1.3 fold; osteocalcin, 1.2 fold) in osteogenic conditions. In addition, alkaline phosphatase production significantly increased (2-fold) on the functionalized surfaces, whereas bone mineral deposition increased by 30% above background levels compared to bare Zr. These findings have the potential to be readily translated to the development of improved Zr and Ti-based implants for accelerated bone repair. 2016 American Chemical Society.
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Love, Dominic T.; Barrett, Tessa J.; White, Melanie Yvonne; Cordwell, Stuart James; Davies, Michael J.; Hawkins, Clare L.Myeloperoxidase (MPO) released at sites of inflammation catalyzes the formation of the oxidants hypochlorous acid (HOCl) and hypothiocyanous acid (HOSCN) from H<inf>2</inf>O<inf>2</inf> and halide and pseudo-halide ions. HOCl, a major oxidant produced under physiological conditions reacts rapidly with many biological molecules, and is strongly linked with tissue damage during inflammatory disease. The role of HOSCN in disease is less clear, though it can initiate cellular damage by pathways involving the selective oxidation of thiol-containing proteins. Utilizing a thiol-specific proteomic approach, we explored the cellular targets of HOSCN in macrophages (J774A.1). We report that multiple thiol-containing proteins involved in metabolism and glycolysis; fructose bisphosphate aldolase, triosephosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and creatine kinase, together with a number of chaperone, antioxidant and structural proteins, were modified in a reversible manner in macrophages treated with HOSCN. The modification of the metabolic enzymes was associated with a decrease in basal glycolysis, glycolytic reserve, glycolytic capacity and lactate release, which was only partly reversible on further incubation in the absence of HOSCN. Inhibition of glycolysis preceded cell death and was seen in cells exposed to low concentrations (?25 ?M) of HOSCN. The ability of HOSCN to inhibit glycolysis and perturb energy production is likely to contribute to the cell death seen in macrophages on further incubation after the initial treatment period, which may be relevant for the propagation of inflammatory disease in smokers, who have elevated plasma levels of the HOSCN precursor, thiocyanate. 2016 Elsevier Inc. All rights reserved.
