ABSTRACT
Introduction: Although cardiac allograft vasculopathy (CAV) remains one of the leading causes of graft failure after heart transplantation (HTx), simultaneous thrombosis of multiple epicardial coronary arteries (CA) is an uncommon finding. Case Report: A 43-year-old male patient with non-ischemic dilated cardiomyopathy underwent successful HTx in 2019. The first two years after HTx were uneventful, surveillance endomyocardial biopsies (EMB) did not reveal any rejection episodes, coronary CTA revealed only minimal non-calcified CA plaques. The patient was admitted to hospital due to fever and chest pain in 2021. Immunosuppressive therapy consisted of tacrolimus, mycophenolate-mofetil and methylprednisolone. ECG verified sinus rhythm. Laboratory test revealed elevated hsTroponin T, NT-proBNP and CRP levels. Cytomegalovirus, SARS-CoV-2-virus and hemoculture testing was negative. Several high-titre donor-specific HLA class I and II antibodies (DSAs;including complement-binding DQ7) could have been detected since 2020. Echocardiography confirmed mildly decreased left ventricular systolic function and apical hypokinesis. EMB verified mild cellular and antibody-mediated rejection (ABMR) according to ISHLT grading criteria. Cardiac MRI revealed inferobasal and apical myocardial infarction (MI);thus, an urgent coronary angiography was performed. This confirmed thrombotic occlusions in all three main epicardial CAs and in first diagonal CA. As revascularization was not feasible, antithrombotic therapy with acetylsalicylic acid, clopidogrel and enoxaparin was started for secondary prevention. Tests for immune system disorders, thrombophilia and cancer were negative. Patient suddenly died ten days after admission. Necropsy revealed intimal proliferation in all three main epicardial CAs, endothelitis, thrombosis, chronic pericoronary fat inflammation, fat necrosis, and subacute MI. CA vasculitis owing to persistent high-titre DSAs, chronic ABMR and acute cellular and antibody-mediated rejection led to multivessel CA thrombosis and acute multiple MI. ABMR after HTx may be underdiagnosed with traditional pathological methods. Pathologies affecting coronary vasculature of HTx patients with DSAs, unique manifestations of CAV lesions and occlusive thrombosis of non-stenotic, non-atherosclerotic lesions should be emphasized.Copyright © 2023
ABSTRACT
Heart transplant (HTX) recipients are prone to develop serious symptoms after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and their vaccination is often ineffective. In this high-volume single center study, we aimed to examine the seroconversion rates achieved with various types and doses of SARS-CoV-2 vaccines and assessed factors influencing vaccine immunogenicity and predictors of severe SARS-CoV-2 infection. 229 HTX recipients were enrolled at a university clinic. Type of the first two doses of vaccine included mRNA, vector and inactivated vaccines as well. We carried out analyses on seroconversion after the second and third doses of vaccination and on severity of coronavirus disease 2019 (COVID-19). Anti-SARS-CoV-2 IgG levels were measured with Elecsys immunoassay (Roche). Effect of the first two vaccine doses was studied on patients who did not suffer SARS-CoV-2 infection before antibody measurement (n=175). Seroconversion after the third vaccine was analysed among seronegative patients after two doses (n=53). Predictors for severe infection defined as pneumonia, hospitalization or death was assessed in all HTX recipients who had COVID-19 (n=92). Logistic regression was applied for further analyses. 62% of the recipients became seropositive after the second vaccination. Longer time between HTX and vaccination (OR: 2.35, 95% CI: 1.28 - 4.49, p=0.007) and mRNA type of vaccine (OR: 4.83, 95% CI: 1.33 - 17.5, p=0.012) were predictors of seroconversion. 58% of the non-responsive patients became seropositive after receiving the third vaccine. Male sex increased the chance of IgG production after the third dose (OR: 5.65, 95% CI: 1.61 - 22.7, p=0.009). Clinical course of SARS-CoV-2 infection was severe in 32%. Of all parameters assessed, only seropositivity was proven to have a protective effect against severe infection (OR: 0.12, 95% CI: 0.02 - 0.64, p=0.019). Longer time since HTX, mRNA vaccine type and male sex promoted seroconversion after SARS-CoV-2 vaccination in HTX recipients. Seropositivity was proven to be protective against severe SARS-CoV-2 infection in single center cohort. Routine screening of HTX patients for anti-SARS-COV-2 antibodies may help to identify patients at risk for severe infection requiring addtional measures of anti-SARS-CoV-2 protection. [ FROM AUTHOR] Copyright of Journal of Heart & Lung Transplantation is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)
ABSTRACT
While the new coronavirus has turned our lives upside down causing millions of deaths, the historically known tuberculosis (TB) disease caused by Mycobacterium tuberculosis (MTB) was responsible for the loss of approximately 1.5 million lives alone in 2021. New anti- TB drugs are in an urgent need. A promising target is dUTPase, an enzyme preventing uracil incorporation into DNA. It is present in all multicellular species and in most microbes. Abolition of its activity potentially leads to DNA double strand breaks and cell death. Therefore, species-specific inhibition of MTB dUTPase may be a successful way of TB disease treatment. Currently no species-specific dUTPase inhibitor exists, but an interaction partner, protein Stl shows significantly different ability to inhibit dUTPase homologues from various species. We use Stl as a model to understand how species- specific differences in dUTPase structure may be harnessed in future inhibitor development. A remarkable species-specific characteristic of MTB dUTPase is a small surface sequence loop playing no direct role in enzyme activity but being essential for mycobacterial survival in a yet unknown way. What is the exact structural background of MTB dUTPase-Stl interaction? For this reason, we have crystallized a complex of MTB dUTPase and a truncated Stl protein mutant. And how the loop sequence may affect the MTB dUTPase protein structure on its own? For this answer, we obtained another X-ray diffraction dataset of a loop-lacking mutant of MTB dUTPase with 1.3 Å resolution. Surprisingly, electron density of the flexible C-terminal “arm” segment of the mutant dUTPase was missing from our dataset, contrary to the already crystallized wildtypeMTB dUTPase structures. We postulate that the loop sequence may restrict conformational flexibility of the dUTPase “arm”, making it more inhibitable by Stl compared to the loop-lacking mutant, as we know from our comparative steady-state enzyme activity inhibition measurements.
ABSTRACT
The importance of proper hygienical behaivour is essential in today's word especially during an ongoing pandemic. Wearing mask became mandatory in many countries during the COVID-19 Pandemic. Recognizing whether people are wearing masks is complicated image recognition task which could be facilitated and automated with machine learning techniques. Camera streams are widely available in indoor environments which can be used for object detection and image processing. Convolutional Neural Networks have been successfully applied in image classification and object recognition task in various application areas. There are already trained and openly available general purpose convolutional neural networks which can be used as an initial version for specific applications. A number of different image datasets are also available for research and industrial purposes. The InceptionV3 Neural Network architecture was used to tailored to determine whether a mask is being worn or not using transfer learning techniques, and convolutional neural networks. A variational autoencoder has also been trained to normalize the dataset with respect to skin colour, angle of the head and among other parameters. This paper describes the implementation of a mask recognition software using transfer learning, a convolutional neural network and a variational autoencoder. © 2021 IEEE.
ABSTRACT
Digital transformation is slow process in education which became an urgent topic in the spring of 2020 due to COVID-19. In mid March, the Hungarian Government closed the schools and universities and the classes were held in online form. This faced both students and teachers with unexpected challenges. Survey was conducted among the Computer Science and Information Technologist students of the Eszterhazy Karoly University at the end of the semester. Our survey was focused on the experience, feelings and overall expression of the students regarding to digital education and recent changes. Moreover, the survey contains questions about technical preparation and infrastructure. The responses are processed by well-known statistical data analysis tools. Based on the results, the students enjoyed the digital education and half of them are willing to continue it in the future. In addition, students would prefer to use their own devices during on tutorials which allow some changes in the labor environments. Unfortunately, some students had technical issues which may be caused by the heterogeneous software environment and can be solved with support material. Digital transformation was considered successful and the feedback will be integrated into our online classes.