354 research outputs found

    Multislice computer tomography (MSCT) for the optimisation of transcatheter aortic valve implantation (TAVI)

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    Transcatheter aortic valve replacement (TAVI) is a novel therapy that is increasingly used to treat patients with severe aortic stenosis at high risk for surgical valve replacement. Patient selection, procedural planning and evaluation all require a detailed analysis of patient anatomy. The role and added value of multislice computer tomography (MSCT) is described as a 3-D imaging modality that enables a comprehensive evaluation of the complex 3-D anatomy of the aortic root, planning of all potential transcatheter access routes and evaluation of prosthesis anatomy interactions post-implantation

    Magnetic Core Matrix Switch Adder

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    The principle of operation of the three input-two output matrix adders is based upon the saturable transformer characteristics of the magnetic cores. The control and driving windings are matrix connected. This presents a selection scheme which produces an almost instantaneous addition or subtraction of two binary numbers. The carry propagate time is about 0.07 μsec per digit for a pulse length of 0.5 μsec at a PRF of 1 mc

    Case report : synergetic effect of ischaemia and increased vagal tone inducing ventricular fibrillation in a patient with Brugada syndrome

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    Background Brugada syndrome (BS) is a hereditary channelopathy associated with syncope, malignant ventricular arrhythmia, and sudden cardiac death. Right ventricular ischaemia and BS have similar underlying substrates precipitating ventricular tachycardia or fibrillation (VF). Case summary A 72-year-old woman with BS and a stenosis on the proximal right coronary artery received several subsequent implantable cardioverter-defibrillator shocks due to VF during an episode of extreme nausea with vomiting. Discussion This case report emphasizes on the synergetic effect of mild ischaemia and increased vagal tone on the substrate responsible for BS to create pathophysiological changes precipitating VF

    Quantifying dietary vitamin K and its link to cardiovascular health: A narrative review

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    Cardiovascular disease is the leading cause of death and disability worldwide. Recent work suggests a link between vitamin K insufficiency and deficiency with vascular calcification, a marker of advanced atherosclerosis. Vitamin K refers to a group of fat-soluble vitamins important for blood coagulation, reducing inflammation, regulating blood calcium metabolism, as well as bone metabolism, all of which may play a role in promoting cardiovascular health. Presently, there is a lack of a comprehensive vitamin K database on individual foods, which are required to accurately calculate vitamin K1 and K2 intake for examination in epidemiological studies. This has likely contributed to ambiguity regarding the recommended daily intake of vitamin K, including whether vitamin K1 and K2 may have separate, partly overlapping functions. This review will discuss the presence of: (i) vitamin K1 and K2 in the diet; (ii) the methods of quantitating vitamin K compounds in foods; and (iii) provide an overview of the evidence for the cardiovascular health benefits of vitamin K in observational and clinical trials

    Impact of vascular screening interventions on perceived threat, efficacy beliefs and behavioural intentions: A systematic narrative review

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    Health-related behaviours contribute to the global burden of cardiovascular disease (CVD). Cardiovascular imaging can be used to screen asymptomatic individuals for increased risk of CVD to enable earlier interventions to promote health-related behaviours to prevent or reduce CVD risk. Some theories of behaviour and behaviour change assume that engagement in a given behaviour is a function of individual threat appraisals, beliefs regarding the performance of behaviour, self-efficacy for performing the desired behaviour and/or dispositions to act (e.g. behavioural intentions). To date, little is known about the impact of cardiovascular imaging interventions on these constructs. This article summarises evidence related to perceived threat, efficacy beliefs, and behavioural intentions after CVD screening. We identified 10 studies (2 RCTs and 8 non-randomised studies, n = 2498) through a combination of screening citations from published systematic reviews and meta-analyses and searching electronic databases. Of these, 7 measured behavioural intentions and perceived susceptibility and 3 measured efficacy beliefs. Findings showed largely encouraging effects of screening interventions on bolstering self-efficacy beliefs and strengthening behavioural intentions. Imaging results that suggest the presence of coronary or carotid artery disease also increased perceived susceptibility to CVD. However, the review also identified some gaps in the literature, such as a lack of guiding theoretical frameworks and assessments of critical determinants of health-related behaviours. By carefully considering the key issues highlighted in this review, we can make significant strides towards reducing CVD risks and improving population health

    Ibrutinib Unmasks Critical Role of Bruton Tyrosine Kinase in Primary CNS Lymphoma.

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    Bruton tyrosine kinase (BTK) links the B-cell antigen receptor (BCR) and Toll-like receptors with NF-κB. The role of BTK in primary central nervous system (CNS) lymphoma (PCNSL) is unknown. We performed a phase I clinical trial with ibrutinib, the first-in-class BTK inhibitor, for patients with relapsed or refractory CNS lymphoma. Clinical responses to ibrutinib occurred in 10 of 13 (77%) patients with PCNSL, including five complete responses. The only PCNSL with complete ibrutinib resistance harbored a mutation within the coiled-coil domain of CARD11, a known ibrutinib resistance mechanism. Incomplete tumor responses were associated with mutations in the B-cell antigen receptor-associated protein CD79B

    The effects of vitamin K-rich green leafy vegetables on bone metabolism: a 4-week randomised controlled trial in middle-aged and older individuals

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    Background: High vegetable intake is associated with beneficial effects on bone. However, the mechanisms remain uncertain. Green leafy vegetables are a rich source of vitamin K1, which is known to have large effects on osteoblasts and osteocalcin (OC) metabolism. Objective: To examine the effects of consumption of two to three extra serves of green leafy vegetables daily on bone metabolism. Methods: Thirty individuals (mean age 61.8 ± 9.9 years, 67% male) completed three experimental phases in a randomised controlled crossover design, each lasting four weeks, with a washout period of four weeks between phases (clinical trial registration: ACTRN12615000194561). The three experimental phases were: (i) increased dietary vitamin K1 by consuming green leafy vegetables (H-K, ~200 g/d containing 164.3 [99.5–384.7] μg/d of vitamin K1), (ii) low vitamin K1 by consuming vitamin K1-poor vegetables (L-K, ~200 g/d containing 9.4 [7.7–11.6] μg/d of vitamin K1), and (iii) control (CON) where participants consumed an energy-matched non-vegetable control. OC forms, total OC (tOC), carboxylated OC (cOC) and undercarboxylated OC (ucOC), were measured in serum pre- and post-intervention for each experimental phase using a sandwich-electrochemiluminescence immunoassay. Results: Pre-intervention tOC, ucOC and ucOC:tOC levels were similar between phases (P \u3e .05). Following H-K, but not L-K, tOC, ucOC and ucOC:tOC levels were significantly lower compared to pre-intervention levels (P ≤ .001) and compared to CON (~14%, 31% and 19%, respectively, all P \u3c .05), while cOC remained unchanged. Conclusions: In middle-aged healthy men and women, an easily achieved increase in dietary intake of vitamin K1-rich green leafy vegetables substantially reduces serum tOC and ucOC suggesting increased entry of OC into bone matrix, where it may improve the material property of bone. In conjunction with previous epidemiological and randomised controlled trial data, these findings suggest that interventions to increase vegetable intake over extended periods should include bone end points including fracture risk
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