Myocardial Perfusion Imaging After Severe COVID-19 Infection Demonstrates Regional Ischemia Rather Than Global Blood Flow Reduction

Background: Acute myocardial damage is common in severe COVID-19. Post-mortem studies have implicated microvascular thrombosis, with cardiovascular magnetic resonance (CMR) demonstrating a high prevalence of myocardial infarction and myocarditis-like scar. The microcirculatory sequelae are incompletely characterized. Perfusion CMR can quantify the stress myocardial blood flow (MBF) and identify its association with infarction and myocarditis. Objectives: To determine the impact of the severe hospitalized COVID-19 on global and regional myocardial perfusion in recovered patients. Methods: A case-control study of previously hospitalized, troponin-positive COVID-19 patients was undertaken. The results were compared with a propensity-matched, pre-COVID chest pain cohort (referred for clinical CMR; angiography subsequently demonstrating unobstructed coronary arteries) and 27 healthy volunteers (HV). The analysis used visual assessment for the regional perfusion defects and AI-based segmentation to derive the global and regional stress and rest MBF. Results: Ninety recovered post-COVID patients {median age 64 [interquartile range (IQR) 54-71] years, 83% male, 44% requiring the intensive care unit (ICU)} underwent adenosine-stress perfusion CMR at a median of 61 (IQR 29-146) days post-discharge. The mean left ventricular ejection fraction (LVEF) was 67 ± 10%; 10 (11%) with impaired LVEF. Fifty patients (56%) had late gadolinium enhancement (LGE); 15 (17%) had infarct-pattern, 31 (34%) had non-ischemic, and 4 (4.4%) had mixed pattern LGE. Thirty-two patients (36%) had adenosine-induced regional perfusion defects, 26 out of 32 with at least one segment without prior infarction. The global stress MBF in post-COVID patients was similar to the age-, sex- and co-morbidities of the matched controls (2.53 ± 0.77 vs. 2.52 ± 0.79 ml/g/min, p = 0.10), though lower than HV (3.00 ± 0.76 ml/g/min, p< 0.01). Conclusions: After severe hospitalized COVID-19 infection, patients who attended clinical ischemia testing had little evidence of significant microvascular disease at 2 months post-discharge. The high prevalence of regional inducible ischemia and/or infarction (nearly 40%) may suggest that occult coronary disease is an important putative mechanism for troponin elevation in this cohort. This should be considered hypothesis-generating for future studies which combine ischemia and anatomical assessment

OntoCAT -- simple ontology search and integration in Java, R and REST/JavaScript

<p>Abstract</p> <p>Background</p> <p>Ontologies have become an essential asset in the bioinformatics toolbox and a number of ontology access resources are now available, for example, the EBI Ontology Lookup Service (OLS) and the NCBO BioPortal. However, these resources differ substantially in mode, ease of access, and ontology content. This makes it relatively difficult to access each ontology source separately, map their contents to research data, and much of this effort is being replicated across different research groups.</p> <p>Results</p> <p>OntoCAT provides a seamless programming interface to query heterogeneous ontology resources including OLS and BioPortal, as well as user-specified local OWL and OBO files. Each resource is wrapped behind easy to learn Java, Bioconductor/R and REST web service commands enabling reuse and integration of ontology software efforts despite variation in technologies. It is also available as a stand-alone MOLGENIS database and a Google App Engine application.</p> <p>Conclusions</p> <p>OntoCAT provides a robust, configurable solution for accessing ontology terms specified locally and from remote services, is available as a stand-alone tool and has been tested thoroughly in the ArrayExpress, MOLGENIS, EFO and Gen2Phen phenotype use cases.</p> <p>Availability</p> <p><url>http://www.ontocat.org</url></p

A novel framework for intelligent surveillance system based on abnormal human activity detection in academic environments

Abnormal activity detection plays a crucial role in surveillance applications, and a surveillance system thatcan perform robustly in an academic environment has become an urgent need. In this paper, we propose a novel framework for an automatic real-time video-based surveillance system which can simultaneously perform the tracking, semantic scene learning, and abnormality detection in an academic environment. To develop our system, we have divided the work into three phases: preprocessing phase, abnormal human activity detection phase, and content-based image retrieval phase. For motion object detection, we used the temporal-differencing algorithm and then located the motions region using the Gaussian function.Furthermore, the shape model based on OMEGA equation was used as a filter for the detected objects (i.e.,human and non-human). For object activities analysis, we evaluated and analyzed the human activities of the detected objects. We classified the human activities into two groups:normal activities and abnormal activities based on the support vector machine. The machine then provides an automatic warning in case of abnormal human activities. It also embeds a method to retrieve the detected object from the database for object recognition and identification using content-based image retrieval.Finally,a software-based simulation using MATLAB was performed and the results of the conducted experiments showed an excellent surveillance system that can simultaneously perform the tracking, semantic scene learning, and abnormality detection in an academic environment with no human intervention

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Direct-acting antiviral treatment for chronic hepatitis C in people who use drugs in a real-world setting

Background Direct-acting antivirals (DAAs) offer high cure rates in people who inject drugs (PWID) with hepatitis C virus (HCV) infection. There are concerns regarding lower response rates among PWID in real life. We evaluated the outcome of DAA therapy in PWID in a real-world setting and the factors that affect it. Methods We performed a retrospective analysis of 174 PWID with chronic hepatitis C who started DAAs in a Greek liver clinic in collaboration with an addiction program. Patients who did not return for reassessment were considered as lost to follow up (LTFU). A logistic regression model was used to assess factors associated with a sustained virological response 12 weeks after treatment completion (SVR12) and LTFU. Results Patients’ mean age was 48±9.2 years and 91/174 (52.3%) were attending opioid substitution treatment programs. Overall, 144/174 (82.8%) patients completed therapy and presented for SVR12 testing, 8/174 (4.6%) did not complete treatment and 22/174 (12.6%) were LTFU. Overall SVR12 was 79.9% (139/174). For those with an available SVR12 test the response rate reached 96.5% (139/144). Regression analysis did not indicate any significant association between patient characteristics and SVR12. Age &lt;45 years and genotype 3 were independent predictors of LTFU. Parallel use was found to have a trend towards LTFU. Conclusions HCV treatment by hepatologists and addiction specialists is feasible, effective and safe in a real-world setting. However, as 12% of patients appear to be LTFU, more emphasis should be placed on interventions guaranteeing follow up for SVR testing and general care. © 2020 Hellenic Society of Gastroenterology

Liver fibrosis staging with combination of APRI and FIB-4 scoring systems in chronic hepatitis C as an alternative to transient elastography

Background Liver disease severity must be determined before treatment of chronic hepatitis C (CHC). We evaluated the diagnostic performance of the APRI and FIB-4 scores compared to transient elastography liver stiffness (TE-LS) in detecting significant fibrosis (F3) or cirrhosis (F4). Methods We retrospectively enrolled 575 patients with CHC who underwent TE-LS between May 2014 and September 2018: 365 (63.5%) male, mean age 51.54±12.4 years. APRI and FIB-4 scores were compared to TE-LS. Results One hundred patients (17.5%) had TE-LS values between 9 and 11.9 kPa, and were classified as F3, while 265 (46%) were classified as F4 (TE-LS ≥12 kPa). APRI and FIB-4 scores predicted F4 patients adequately using cutoff values of 0.65 (sensitivity 85.5%, specificity 77%) and 1.63 (sensitivity 91%, specificity 77%), respectively. Cutoff values of 0.64 for APRI and 1.46 for FIB-4 predicted F3/F4 patients (sensitivity 72% and 81.5%; specificity 83% and 79%, respectively). The use of these cutoff values with APRI and FIB-4 in combination adequately predicted patients with significant fibrosis or cirrhosis (positive predictive value 91.5%), while cutoff values of 0.3 and 0.98, respectively, predicted F1/F2 patients with specificity 94.5% and sensitivity 26.5%, suggesting that in 58.5% of patients TE-LS could possibly be avoided. Conclusions The APRI/FIB-4 combination performed well in predicting significant fibrosis, while FIB-4 performed well in predicting cirrhosis. These noninvasive biochemical markers could be used as screening tools instead of LS measurement, which is not widely available. Further prospective validation studies are required to confirm this finding. © 2019 Hellenic Society of Gastroenterology