Quantitative Assessment of Chest CT Patterns in COVID-19 and Bacterial Pneumonia Patients: a Deep Learning Perspective

Background: It is difficult to distinguish subtle differences shown in computed tomography (CT) images of coronavirus disease 2019 (COVID-19) and bacterial pneumonia patients, which often leads to an inaccurate diagnosis. It is desirable to design and evaluate interpretable feature extraction techniques to describe the patient’s condition. Methods: This is a retrospective cohort study of 170 confirmed patients with COVID-19 or bacterial pneumonia acquired at Yeungnam University Hospital in Daegu, Korea. The lung and lesion regions were segmented to crop the lesion into 2D patches to train a classifier model that could differentiate between COVID-19 and bacterial pneumonia. The K-means algorithm was used to cluster deep features extracted by the trained model into 20 groups. Each lesion patch cluster was described by a characteristic imaging term for comparison. For each CT image containing multiple lesions, a histogram of lesion types was constructed using the cluster information. Finally, a Support Vector Machine classifier was trained with the histogram and radiomics features to distinguish diseases and severity. Results: The 20 clusters constructed from 170 patients were reviewed based on common radiographic appearance types. Two clusters showed typical findings of COVID-19, with two other clusters showing typical findings related to bacterial pneumonia. Notably, there is one cluster that showed bilateral diffuse ground-glass opacities (GGOs) in the central and peripheral lungs and was considered to be a key factor for severity classification. The proposed method achieved an accuracy of 91.2% for classifying COVID-19 and bacterial pneumonia patients with 95% reported for severity classification. The CT quantitative parameters represented by the values of cluster 8 were correlated with existing laboratory data and clinical parameters. Conclusion: Deep chest CT analysis with constructed lesion clusters revealed well-known COVID-19 CT manifestations comparable to manual CT analysis. The constructed histogram features improved accuracy for both diseases and severity classification, and showed correlations with laboratory data and clinical parameters. The constructed histogram features can provide guidance for improved analysis and treatment of COVID-19. © 2021. The Korean Academy of Medical Sciences.1

Remission of intestinal Behçet's disease treated with anti-tumor necrosis factor α monoclonal antibody (Infliximab)

Behçet's disease (BD) is a chronic relapsing multisystem disease characterized by oral ulceration, genital ulceration and ocular lesions. Gastrointestinal involvement is rare, often difficult to treat and associated with a high mortality rate. We treated a 47-year-old Korean man with BD who had a recurrent intestinal ulcer with tumor necrosis factor α antibody (infliximab); he initially underwent right hemicolectomy due to uncontrolled intestinal bleeding. For patients with intestinal BD who fail to respond to conventional treatment, infliximab may be a safe and effective new therapeutic option

Effect of vitamin E in nonalcoholic fatty liver disease with metabolic syndrome: A propensity score-matched cohort study

Background/AimsVitamin E improves the biochemical profiles and liver histology in nonalcoholic steatohepatitis, but the role of vitamin E is not clearly defined in the management of nonalcoholic fatty liver disease (NAFLD) which includes both simple steatosis and steatohepatitis. Co-morbid metabolic syndrome increases the probability of steatohepatitis in NAFLD. In this study, we aimed to determine the short-term effects of vitamin E and off-treatment durability of response in a propensity-score matched cohort of NAFLD patients with metabolic syndrome.MethodsA retrospective cohort was constructed by retrieving 526 consecutive NAFLD patients from the electronic medical record data warehouse of a tertiary referral hospital in South Korea. Among them, 335 patients (63.7%) had metabolic syndrome and were eligible for vitamin E therapy. In order to assess the effect of vitamin E, propensity score matching was used by matching covariates between control patients (n=250) and patients who received vitamin E (n=85).ResultsThe PS-matched vitamin E group (n=58) and control group (n=58) exhibited similar baseline metabolic profiles. After 6 months of vitamin E therapy, the mean ALT levels decreased significantly compared to PS-matched control (P<0.01). The changes in metabolic profiles (body weight, lipid and glucose levels) did not differ between control and vitamin E groups during the study period.ConclusionsShort-term vitamin E treatment significantly reduces ALT levels in NAFLD patients with metabolic syndrome, but metabolic profiles are not affected by vitamin E

Structural and Physiological Exploration of Salmonella Typhi YfdX Uncovers Its Dual Function in Bacterial Antibiotic Stress and Virulence

YfdX is a prokaryotic protein encoded by several pathogenic bacteria including Salmonella enterica serovar Typhi, which causes one of the most fatal infectious diseases, typhoid fever. YfdX is a product of the yfdXWUVE operon and is known to be under the control of EvgA, a regulator protein controlling the expression of several proteins involved in response to environmental stress, in Escherichia coli. Nevertheless, unlike other proteins encoded by the same operon, the structural and physiological aspects of YfdX have been poorly characterized. Here, we identified a previously unknown pH-dependent stoichiometric conversion of S. Typhi YfdX between dimeric and tetrameric states; this conversion was further analyzed via determining its structure by X-ray crystallography at high resolution and by small-angle X-ray scattering in a solution state and via structure-based mutant studies. Biologically, YfdX was proven to be critically involved in Salmonella susceptibility to two β-lactam antibiotics, penicillin G and carbenicillin, as bacterial growth significantly impaired by its deficiency upon treatment with each of the two antibiotics was recovered by chromosomal complementation. Furthermore, by using Galleria mellonella larvae as an in vivo model of Salmonella infection, we demonstrated that Salmonella virulence was remarkably enhanced by YfdX deficiency, which was complemented by a transient expression of the wild-type or dimeric mutant but not by that of the monomeric mutant. The present study work provides direct evidence regarding the participation of YfdX in Salmonella antibiotic susceptibility and in the modulation of bacterial virulence, providing a new insight into this pathogen’s strategies for survival and growth