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Quantitative analyses and case studies of hybrid PET-MRI imaging
Published in Yi-Hwa Liu, Albert J. Sinusas, Hybrid Imaging in Cardiovascular Medicine, 2017
Leon J. Menezes, Eleanor C. Wicks, Brian F. Hutton
Amyloidosis is a clinical disorder that arises from the aggregation of insoluble fibrous deposits of misfolded proteins. Deposition of fibrillary material and the toxic effects of precursor soluble intermediates result in progressive organ dysfunction, which manifest as heart failure with restrictive physiology (Gertz, Dispenzieri, and Sher 2014). The recent development of PET tracers for amyloid plaque identification in Alzheimer’s disease has generated potential interest in the evaluation of cardiac amyloidosis, a condition that is imaged using MRI (Fontana et al. 2014) and 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) SPECT (Hutt et al. 2014). 11C-PIB and 18F-Florbetapir have been used to depict systemic and cardiac amyloid (Antoni et al. 2013; Dorbala et al. 2014; Lee et al. 2015). Validation with T1 mapping and ECV measurements with simultaneous PET/MRI could possibly allow earlier diagnosis and treatment monitoring (Figure 16.4).
Kidney Function and Uremia
Published in Sirshendu De, Anirban Roy, Hemodialysis Membranes, 2017
Carpal tunnel syndrome is characterized with local deposition of beta2 microglobulin (B2M). Its toxic action surfaces only after prolonged exposure. It is the root cause behind the syndrome known as dialysis-related amyloidosis (DRA) that starts after prolonged dialysis treatment (several years) or in aged dialysis patients.20
Quinoline yellow (food additive) induced conformational changes in lysozyme: a spectroscopic, docking and simulation studies of dye-protein interactions
Published in Preparative Biochemistry & Biotechnology, 2020
Mohd Shahnawaz Khan, Sheraz Bhatt, Shams Tabrez, Md Tabish Rehman, Majed Saleh Alokail, Mohamed F. AlAjmi
Hen egg-white lysozyme (HEWL) is a comparatively small (14.3 kDa) protein with 129 amino acids and 4 intramolecular disulfide bridges and belongs to α + β class of proteins.[13,14] Human lysozyme mutants, form amyloid-like aggregates and are deposited in the liver and kidney leading to hereditary non-neuropathic systemic amyloidosis.[15] A small peptide in HEWL of nearly 49 amino acids is hydrolyzed by heating at low pH and has been recognized as the amyloidogenic core of the protein.[16] HEWL shares 60% homology with human lysozyme, and also shows folding/unfolding and amyloid fibrillation characteristics.[17] Hence, HEWL was used as a model protein to determine the role of QY in inducing amyloid fibrillation. In the present study, we have examined the conformational response of HEWL in the presence of different concentrations of QY at physiological pH (7.4). The study investigated the potential mechanism of dye-protein interaction and HEWL aggregation. To the best of our knowledge, this is the first report on HEWL and QY interaction and subsequent amyloidogenesis of the model protein.
Device profile of the AltaValve system for transcatheter mitral valve replacement: overview of its safety and efficacy
Published in Expert Review of Medical Devices, 2020
Alberto Alperi, David del Val, Alfredo Nunes Ferreira-Neto, Mathieu Bernier, Afonso B Freitas-Ferraz, François Dagenais, Josep Rodés-Cabau
A second reported case was carried out through a trans-apical approach in an 89 years-old male presenting prohibitive surgical risk due to comorbidity burden as well as posterior leaflet calcification precluding transcatheter mitral valve repair [21]. Besides, its exclusively posterior mitral annular calcification pattern prevented off-label use of commercially available prosthesis intended for aortic position. Based on CT measures, a 75 mm frame height, 70 mm frame width, and 46 mm annular ring AltaValve device was selected. After deployment and gentle adjustment, valve function was considered optimal, showing the trans-esophageal echocardiography mild paravalvular MR with normal leaflet motion and no stenosis. The patient had a sudden death on post-procedural day 5 after being weaned off from vasopressor support and mechanical ventilation. The autopsy revealed diffused myocardial amyloid deposition and a postmortem cardiac amyloidosis diagnosis was made.
Skin temperature of the foot: comparing transthyretin Familial Amyloid Polyneuropathy and Diabetic Foot patients
Published in Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 2019
Adérito Seixas, Maria do Carmo Vilas-Boas, Rui Carvalho, Teresa Coelho, Kurt Ammer, João Paulo Vilas-Boas, Joaquim Mendes, João Paulo Silva Cunha, Ricardo Vardasca
Amyloid neuropathies are severe and life-threatening illnesses characterised by endoneurial amyloid deposits with an estimated European prevalence of 47/100 000 in 2014, with more than 100 different mutations identified (Parman et al. 2016). The most common form of amyloid mutation, first identified in the 1980s, is transthyretin amyloidosis, or TTR-FAP. The diagnosis of TTR-FAP presents a significant challenge because of its rarity, complexity, multisystemic character and variable presentation that frequently leads to misdiagnosis (Adams et al. 2016). Clinically, this condition manifests a sensorimotor and autonomic neuropathy that is progressive, symmetric and irreversible (Hund 2012). It typically starts with sensory disturbances in the toes and moves upward to more proximal parts of the legs usually involving the hands by the time the knees are reached (Hund 2012). Initial sensorimotor clinical manifestations include paresthesias, numbness, neuralgic pain, reduced nociception, and thermal sensitivity and are often subjective, as they are reported by patients and sometimes not confirmed by neurophysiological investigation (Lefaucheur et al. 2013; Conceição et al. 2014). Data are scarce regarding the burden of foot ulcers in TTR-FAP. It is often mentioned in reference papers (e.g. Planté-Bordeneuve and Said 2011) that the loss of pain sensation may lead to the development of foot ulcers and osteoarthropathy but few papers report objective data, however, a large single-centre study reported that plantar ulcers were the inaugural symptoms in 5.2% of the patients (Coutinho et al. 1980).