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1.
Mutations in transmembrane proteins: diseases, evolutionary insights, prediction and comparison with globular proteins.
Zaucha, J, Heinzinger, M, Kulandaisamy, A, Kataka, E, Salvádor, ÓL, Popov, P, Rost, B, Gromiha, MM, Zhorov, BS, Frishman, D
Briefings in bioinformatics. 2021;(3)
Abstract
Membrane proteins are unique in that they interact with lipid bilayers, making them indispensable for transporting molecules and relaying signals between and across cells. Due to the significance of the protein's functions, mutations often have profound effects on the fitness of the host. This is apparent both from experimental studies, which implicated numerous missense variants in diseases, as well as from evolutionary signals that allow elucidating the physicochemical constraints that intermembrane and aqueous environments bring. In this review, we report on the current state of knowledge acquired on missense variants (referred to as to single amino acid variants) affecting membrane proteins as well as the insights that can be extrapolated from data already available. This includes an overview of the annotations for membrane protein variants that have been collated within databases dedicated to the topic, bioinformatics approaches that leverage evolutionary information in order to shed light on previously uncharacterized membrane protein structures or interaction interfaces, tools for predicting the effects of mutations tailored specifically towards the characteristics of membrane proteins as well as two clinically relevant case studies explaining the implications of mutated membrane proteins in cancer and cardiomyopathy.
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2.
Radionuclide Imaging of Cardiac Amyloidosis and Sarcoidosis: Roles and Characteristics of Various Tracers.
Hotta, M, Minamimoto, R, Awaya, T, Hiroe, M, Okazaki, O, Hiroi, Y
Radiographics : a review publication of the Radiological Society of North America, Inc. 2020;(7):2029-2041
Abstract
Amyloidosis and sarcoidosis are systemic diseases that affect multiple organ systems. Accurate diagnosis of cardiac amyloidosis and sarcoidosis is particularly important because cardiac involvement can be fatal. Amyloidosis is characterized by the deposition of amyloid fibrils, and cardiac amyloidosis is classified into amyloid immunoglobulin light chain (AL) and amyloid transthyretin (ATTR) types. Radionuclide tracers for amyloidosis include (a) bone tracers, (b) amyloid-directed molecules, and (c) PET amyloid agents. Bone tracers are particularly sensitive in detection of ATTR type amyloidosis, whereas PET amyloid agents show a higher affinity for the AL type. In sarcoidosis, gallium 67 (67Ga) citrate scintigraphy and fluorine 18 (18F) fluorodeoxyglucose (FDG) PET are pivotal to diagnosis of cardiac sarcoidosis, and 18F-FDG PET/CT has particularly high efficacy in detection of sarcoidosis and monitoring of response to therapy. A major limitation of 18F-FDG is physiologic uptake in the myocardium, which can remain in approximately 20% of patients even after elaborate preparation (eg, prolonged fasting >12-18 hours, modification to a high-fat and low-carbohydrate diet, and injection of unfractionated heparin). This limitation has led to a search for potential new tracers. Recently introduced tracers that show promise include those used in somatostatin receptor imaging and cellular proliferation imaging, which provide detectability as high as that for 18F-FDG without requiring dietary restrictions and have potential for monitoring disease activity. ©RSNA, 2020.
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3.
Contemporary Application of Cardiovascular Magnetic Resonance Imaging.
Han, Y, Chen, Y, Ferrari, VA
Annual review of medicine. 2020;:221-234
Abstract
Cardiovascular magnetic resonance imaging (CMR) is a comprehensive and versatile diagnostic and prognostic imaging modality that plays an increasingly important role in management of patients with cardiovascular disease. In this review, we discuss CMR applications in nonischemic cardiomyopathy, ischemic heart disease, arrhythmias, right ventricular diseases, and valvular heart disease. We emphasize the quantitative nature of CMR in current practice, from volumes, function, myocardial strain analysis, and late gadolinium enhancement to parametric mapping, including T1, T2, and T2* relaxation times and extracellular volume fraction assessment.
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4.
[Valproic acid-induced hyperammonemic encephalopathy in a patient receiving valproic acid monotherapy].
Yamada, H, Shishido, T, Mukai, T, Araki, M, Naka, H, Tokinobu, H
Rinsho shinkeigaku = Clinical neurology. 2019;(5):258-263
Abstract
A 79-year-old female was diagnosed with epilepsy because she experienced loss of consciousness twice in January and February and then had a seizure in June 2016. She was treated with 800 mg sodium valproate (sustained release). After 3 days, she experienced loss of appetite, and more than 3 days later, disturbance of consciousness. Serum valproic acid (VPA) concentration was 128.3 μg/ml and serum ammonia was 404 μmol/l. Cerebral edema and status epilepticus occurred. Severe neurological dysfunction remained, even after treatment with continuous hemodiafiltration and levocarnitine. VPA is widely used for the treatment of generalized epilepsy. VPA-induced hyperammonemic encephalopathy is a rare but serious adverse event of VPA. Thus, we must pay attention to serum ammonia levels when using VPA, even VPA monotherapy.
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5.
PET/CT Evaluation of Cardiac Sarcoidosis.
Bois, JP, Muser, D, Chareonthaitawee, P
PET clinics. 2019;(2):223-232
Abstract
The increasing implementation of advanced cardiovascular imaging in the form of cardiac PET/CT has had a significant impact on the management of cardiac sarcoidosis, which continues to evolve. This review summarizes the role of PET/CT imaging in sarcoidosis with a specific focus on (1) indications, (2) patient preparation, (3) test performance, (4) study interpretation, (5) clinical relevance of findings, (6) comparison to alternative imaging modalities, and finally (7) introduction of areas of anticipated development and research.
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6.
Calcium Scoring for Cardiovascular Computed Tomography: How, When and Why?
Carr, JJ
Radiologic clinics of North America. 2019;(1):1-12
Abstract
Cardiovascular disease is the leading cause of death in the United States and worldwide. Despite major advances in the treatment of acute myocardial infarction, enhanced prevention of ischemic heart disease remains critical to improving the health of individuals and communities. The computed tomographic coronary artery calcium score is an established imaging biomarker that identifies the presence and amount of coronary atherosclerosis in an individual and their future risk for clinical cardiovascular disease and premature cardiovascular death. This article describes the process of performing a computed tomography scan for coronary artery calcium, quantifying the score and interpreting the results.
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7.
Advanced cardiovascular imaging for the evaluation of cardiac sarcoidosis.
Bravo, PE, Singh, A, Di Carli, MF, Blankstein, R
Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology. 2019;(1):188-199
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Abstract
Cardiac sarcoidosis (CS) remains an intriguing infiltrating disorder and one of the most important forms of inflammatory cardiomyopathy. Identification of patients with CS is of extreme importance because they are at higher risk of sudden death, and heart-failure progression. And while it remains a diagnostic conundrum, a great amount of experience has been accumulated over the last decade with the advent of fluorine-18 fluorodeoxyglucose positron emission tomography and cardiac magnetic resonance with late gadolinium enhancement imaging. They have both proven to be advanced imaging techniques that provide important, and often complementary, diagnostic and prognostic information for the management of CS. However, they have also shown to have limitations, and, thus, there is a continued need for developing more specific imaging probes for identifying cardiac inflammation. The aim of the present manuscript is to provide the reader with a better understanding of the histopathology of the disease, how this potentially relates to noninvasive imaging detection, and the best strategies available for the diagnosis and management of patients with CS.
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8.
Patient page-sarcoidosis imaging.
Bois, JP, Chareonthaitawee, P
Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology. 2019;(1):222-226
Abstract
Optimizing our imaging capabilities for patients with cardiac sarcoidosis is critical as it has diagnostic, prognostic, and therapeutic implications. 18FDG PET/CT has the highest sensitivity for the detection of CS but requires specific dietary preparation that is difficult for patients to follow which may lead to ineffective suppression of physiologic 18FDG uptake. This may result in inconclusive scan results in up to 30% of patients undergoing 18FDG PET/CT imaging for CS. Therefore, it is imperative that we relay to our patients the importance of dietary preparation for CS PET imaging and then provide simple, easy to follow instructions for them. The current patient protocol is designed to achieve these two objectives.
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9.
Calcium channel blockers for preventing cardiomyopathy due to iron overload in people with transfusion-dependent beta thalassaemia.
Sadaf, A, Hasan, B, Das, JK, Colan, S, Alvi, N
The Cochrane database of systematic reviews. 2018;(7):CD011626
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Abstract
BACKGROUND Beta thalassaemia is a common inherited blood disorder. The need for frequent blood transfusions in this condition poses a difficult problem to healthcare systems. The most common cause of morbidity and mortality is cardiac dysfunction from iron overload. The use of iron chelation therapy has reduced the severity of systemic iron overload but specific, non-toxic treatment is required for removal of iron from the myocardium. OBJECTIVES To assess the effects of calcium channel blockers combined with standard iron chelation therapy in people with transfusion-dependent beta thalassaemia on the amount of iron deposited in the myocardium, on parameters of heart function, and on the incidence of severe heart failure or arrhythmias and related morbidity and mortality. SEARCH METHODS We searched the Cochrane Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched ongoing trials databases, and the reference lists of relevant articles and reviews.Date of last search: 24 February 2018. SELECTION CRITERIA We included randomised controlled trials of calcium channel blockers combined with standard chelation therapy compared with standard chelation therapy alone or combined with placebo in people with transfusion-dependent beta thalassaemia. DATA COLLECTION AND ANALYSIS Two authors independently applied the inclusion criteria for the selection of trials. Two authors assessed the risk of bias of trials and extracted data and a third author verified these assessments. The authors used the GRADE system to assess the quality of the evidence. MAIN RESULTS Two randomised controlled trials (n = 74) were included in the review; there were 35 participants in the amlodipine arms and 39 in the control arms. The mean age of participants was 24.4 years with a standard deviation of 8.5 years. There was comparable participation from both genders. Overall, the risk of bias in included trials was low. The quality of the evidence ranged across outcomes from low to high, but the evidence for most outcomes was judged to be low quality.Cardiac iron assessment, as measured by heart T2*, did not significantly improve in the amlodipine groups compared to the control groups at six or 12 months (low-quality evidence). However, myocardial iron concentration decreased significantly in the amlodipine groups compared to the control groups at both six months, mean difference -0.23 mg/g (95% confidence interval -0.07 to -0.39), and 12 months, mean difference -0.25 mg/g (95% confidence interval -0.44 to -0.05) (low-quality evidence). There were no significant differences between treatment and control groups in serum ferritin (low-quality evidence), liver T2* (low-quality evidence), liver iron content (low-quality evidence) and left ventricular ejection fraction (low-quality evidence). There were no serious adverse events reported in either trial; however, one trial (n = 59) reported mild adverse events, with no statistically significant difference between groups (low-quality evidence). AUTHORS' CONCLUSIONS The available evidence does not clearly suggest that the use of calcium channel blockers is associated with a reduction in myocardial iron in people with transfusion-dependent beta thalassaemia, although a potential for this was seen. There is a need for more long-term, multicentre trials to assess the efficacy and safety of calcium channel blockers for myocardial iron overload, especially in younger children. Future trials should be designed to compare commonly used iron chelation drugs with the addition of calcium channel blockers to investigate the potential interplay of these treatments. In addition, the role of baseline myocardial iron content in affecting the response to calcium channel blockers should be investigated. An analysis of the cost-effectiveness of the treatment is also required.
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10.
Prevention of Keshan Disease by Selenium Supplementation: a Systematic Review and Meta-analysis.
Zhou, H, Wang, T, Li, Q, Li, D
Biological trace element research. 2018;(1):98-105
Abstract
Systematic review (SR) of high-quality studies provides superior evidence, but an SR has not been conducted to evaluate the association between Keshan disease (KD) and selenium deficiency because SR was not available when KD was highly prevalent in the 1950s to 1970s. The objective of this study was to update our understanding of the etiology of KD and provide evidence for policies and strategies in KD surveillance, prevention, and control. We identified related studies by searching the CNKI, Wanfang, CQVIP, SinoMed, CMCI, PubMed, Embase, and EBSCO databases from January 1935 to April 2017. Community trials that met the inclusion criteria were included. Risk ratios (RR) with corresponding 95% confidence intervals (CI) were pooled to compare incidences between the two groups. A total of 17 articles (including 41 studies) were included. In total, the studies included 1,983,238 subjects, 683,075 of which were in experimental groups and 1,300,163 of which were in control groups. The protection rates were over 80% in 35 studies, and the overall effect (risk ratio) was 0.14 [95% CI (0.12, 0.16), P < 0.05]. Potential publication bias was observed in the funnel plots, but the results of Egger's and Begg's tests showed that there was no evidence of publication bias. Giving selenium supplements to the residents of KD endemic areas significantly reduced the incidence of KD. Selenium deficiency is therefore a cause of KD by the criterion of causation in modern epidemiology. Selenium should be included in the KD surveillance program. The description of "unknown cause" in the definition of KD may be inappropriate.