AMICOUMACIN-BASED PRODRUG DEVELOPMENT APPROACH

Coronavirus disease COVID-19, caused by the SARS-CoV-2 virus, is highly contagious and has a severe morbidity. Providing care to patients with COVID-19 requires the development of new types of antiviral drugs. The aim of this work is to develop a prodrug for the treatment of coronavirus disease using the antibiotic Amicoumacin A (Ami), the mechanism of action of which is based on translation inhibition. Enzymatic hydrolysis of an inactivated prodrug by the SARS-CoV-2 main protease can lead to the release of the active Ami molecule and, as a consequence, the suppression of protein biosynthesis in infected cells. To test the proposed hypothesis, a five-stage synthesis of an inactivated analogue of Amicoumacin A was carried out. Its in vitro testing with the SARS-CoV-2 recombinant protease MPro showed a low percentage of hydrolysis. Further optimization of the peptide fragment of the inactivated analog recognized by the SARS-CoV-2 MPro protease may lead to an increase in proteolysis and the release of Amicoumacin A.

Experience of Using Remdesivir in Patients with Novel Coronavirus Infection

Timely, effective, and safe antiviral therapy in COVID-19 patients reduces complications, disability and mortality rates. The greatest concern with remdesivir is the risk of drug-induced liver injury, including in patients whose liver function is compromised by COVID-19. The aim of the study was to investigate the efficacy and safety of remdesivir in patients with confirmed SARSCoV-2 infection who had been admitted to an infectious diseases hospital in the Volgograd region in March 2022. Materials and methods: the authors carried out an open, non-randomised, single-arm study using medical records of 234 patients who had been diagnosed with "U07.1 COVID-19, virus identified” and prescribed remdesivir upon admission. The effectiveness of therapy was evaluated using two criteria: the need for oxygen supplementation or ventilatory support, or mortality. The authors conducted the evaluation on days 7, 14, and 28 using the six-point ordinal severity scale by Y. Wang et al. The safety of therapy was assessed on the basis of complaints and changes in laboratory findings. Results: for the patients prescribed remdesivir at admission, the 7-day mortality rate was 3.0%, the 14-day mortality rate was 5.6%, and the 28-day mortality rate was 7.3%. With the exception of a patient with myocardial infarction, all the patients who had been hospitalised with mild COVID-19 and prescribed remdesivir did not require oxygen therapy and/or transfer to intensive care and were discharged following recovery. The patients with moderate to severe COVID-19 had the 14-day mortality rate of 6.4% and the 28-day mortality rate of 8.6%. 17 patients (7.2%) discontinued remdesivir prematurely for various reasons, including adverse drug reactions. Remdesivir therapy of 5-10 days was associated with an increase in ALT activity by 2.7 ± 0.8 times in 15.9% of patients with mild COVID-19, by 3.8 ± 1.8 times in 20.4% of patients with moderately severe COVID-19, and by 4.8 ± 2.7 times in 24% (12/50) of patients with severe COVID-19. In two patients (0.9%), the increase exceeded 10-fold the upper limit of normal. Conclusions: the obtained results support recommending remdesivir to patients with mild, moderate and severe COVID-19, including those with moderately elevated baseline activity of hepatic transaminases.

Role of vitamin D in modulating the immune response to SARS-CoV-2 and other coronavirus infections

In recent years, new data have been obtained on the significant prevalence of vitamin D (VD) deficiency in the population, and knowledge about the role of vitamin D in the regulation of many physiological processes in the body, including the functioning of the immune system, has increased. The SARS-CoV-2 pandemic has further highlighted the issue of an adequate immune response in vitamin D deficiency. Objective of the review. To present and summarize the evidence on the role of VD in different parts of the immune response in COVID-19, to analyze available studies of the VD status effect on the course and outcome of COVID-19 in patients from different population groups. Material and methods. A search of domestic and foreign literature on the role of VD in the immune response in respiratory viral infections and SARS-CoV-2, as well as practical measures of VD-status correction in COVID-19, was performed. We used Scopus, Web of Science, PubMed, Google Scholar, eLibrary, and Cyberleninka databases. Results. Numerous clinical and observational studies have found an association between 25-hydroxyvitamin D levels, COVID-19 severity, and mortality. This association can be explained by the multifaceted role of vitamin D in the physiology of the human immune and endocrine systems. On the immunological side, the active form of VD promotes the secretion of antimicrobial peptides responsible for inhibiting viral replication and stimulates autophagy by increasing the level of Beclin1 protein and decreasing the level of mTOR protein regulating cellular homeostasis. It leads to the presentation of antigens followed by activation of the antiviral pathway of type I interferons. VD also stabilizes intercellular junctions, including those in the airway epithelium, reducing their permeability to pathogens, stimulates the activity of angiotensin-converting enzyme-2, whose receptors are a conduit for SARS-CoV-2 into cells, and several pathophysiological responses associated with the disease symptoms and acute lung injury. Adequate vitamin D status can provide significant benefits during the pandemic. Conclusion. To date, ideas about the role of vitamin D in regulating the immune response in respiratory infections have significantly expanded. However, its use in the complex preventive measures and adjuvant therapy of viral infections, including COVID-19, should be the subject of further scientific research.

METABOLIC BIOLOGICAL MARKERS FOR DIAGNOSING AND MONITORING THE COURSE OF TUBERCULOSIS.

The international biomedical community has been currently facing a need to find a simple and most accessible type of analysis that helps to diagnose tuberculosis (TB) with the maximum reliability even before the onset of clinical manifestations. Tuberculosis results in more deaths than any other pathogen, second only to pneumonia caused by the SARS-CoV-2 virus, but the majority of infected people remain asymptomatic. In addition, it is important to develop methods to distinguish various forms of tuberculosis infection course at early stages and to reliably stratify patients into appropriate groups (persons with a rapidly progressing infection, chronic course, latent infection carriers). Immunometabolism investigates a relationship between bioenergetic pathways and specific functions of immune cells that has recently become increasingly important in scientific research. The host anti-mycobacteria immune response in tuberculosis is regulated by a number of metabolic networks that can interact both cooperatively and antagonistically, influencing an outcome of the disease. The balance between inflammatory and immune reactions limits the spread of mycobacteria in vivo and protects from developing tuberculosis. Cytokines are essential for host defense, but if uncontrolled, some mediators may contribute to developing disease and pathology. Differences in plasma levels of metabolites between individuals with advanced infection, LTBI and healthy individuals can be detected long before the onset of the major related clinical signs. Changes in amino acid and cortisol level may be detected as early as 12 months before the onset of the disease and become more prominent at verifying clinical diagnosis. Assessing serum level of certain amino acids and their ratios may be used as additional diagnostic markers of active pulmonary TB. Metabolites, including serum fatty acids, amino acids and lipids may contribute to detecting active TB. Metabolic profiles indicate about increased indolamine 2.3-di-oxygenase 1 (IDO1) activity, decreased phospholipase activity, increased adenosine metabolite level, and fibrous lesions in active vs. latent infection. TB treatment can be adjusted based on individual patient metabolism and biomarker profiles. Thus, exploring immunometabolism in tuberculosis is necessary for development of new therapeutic strategies. Copyright © 2022 Saint Petersburg Pasteur Institute. All rights reserved.

Coagulopathy and thromboembolism in children with COVID-19 - pathophysiology, thrombotic risk, clinical manifestations, and management

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the beginning of the pandemic, it has been generally accepted that children infected with SARS-CoV-2 either stay asymptomatic or present benign symptoms. Yet SARS-CoV-2 is widely known to cause serious consequences in children and adolescents. Complications may develop during infection, several weeks afterwards, or in the course of multisystem inflammatory syndrome in children (MIS-C). MIS-C manifests with fever, gastrointestinal, cardiovascular and/or neurological symptoms. Moreover, thromboembolism is a relatively common complication of COVID-19 and MIS-C. The purpose of this work was to review current reports on thromboembolic complications among children who underwent SARS-CoV-2 infection. Among the published cases of MIS-C, thromboembolic incidents ranged from 1.4% to 6.5%, taking the form of a brain infarct, deep vein thrombosis, pulmonary embolism, or splenic infarct. Several mechanisms leading to thrombosis in COVID-19 in children are considered. The development of acute infection in the lungs results in local clot formation in the pulmonary microcirculation, leading to perfusion disturbances. ADAMTS13 activity is also mildly reduced in patients infected with SARS-CoV-2, increasing the risk of microthrombosis. COVID-19-associated coagulopathy is characterized by elevated D-dimers and fibrinogen levels. Significantly increased D-dimers probably represent activation of coagulation caused by viremia and cytokine storm, as well as possible organ dysfunction. The treatment of thromboembolism in children includes low and high molecular weight heparins and acetylsalicylic acid. Pediatricians should be aware of the possible multiple complications associated with COVID-19 in children, including thromboembolic incidents. Copyright © 2022 Sciendo. All rights reserved.

Mineralizing angiopathy: an underrecognized clinicoradiologic entity

Case Report: Initial History/Presentation: A term vaccinated 7-month-old male with a history of eczema presents with two hours of right-sided hemiplegia and hemidystonia. Parents deny loss of consciousness, altered mental status, or facial symptoms. He has no known history of recent or remote head trauma. Patient may have had COVID two months prior when he had upper respiratory symptoms, with his mother testing COVID+ at that time. Of note, he received a Moderna COVID vaccination one day prior to onset of symptoms. Physical Exam: Pertinent exam findings include CN II-XII intact, right-sided upper and lower extremity strength 3/5, sensation intact, and truncal ataxia while seated. Physical exam is otherwise unremarkable. Diagnostic Evaluation: Initial lab work revealed leukocytosis (20.9), but otherwise a reassuring CMP, triglycerides, HDL, and LDL. PTT was elevated, but normal on recheck. Protein C antigen and activity were low, but deemed non-concerning by hematology. All other hypercoagulable labs were normal. On imaging, CT Brain showed linear calcifications in bilateral basal ganglia suggestive of mineralizing angiopathy. HisCTA head/neckwas negative.MRI Brain revealed an acute infarct of the body/tail of the left caudate nucleus, posterior limb of internal capsule, and posterior putamen. Clinical Course/Follow-up: Our patient was started on Aspirin 4 mg/kg daily. Throughout the course of his 3-day inpatient stay, he had mild improvement of right-sided strength and function, and continued improvement upon follow-up with his pediatrician. Given the short interval between receiving his COVID vaccination and onset of symptoms, his case was reported to the Vaccine Adverse Event Reporting System. Conclusion(s): From a radiological perspective, mineralizing angiopathy is an uncommon but familiar finding seen in up to 5% of all neonatal head ultrasounds and increasing to nearly 20% in preterm infants. It is most commonly associated with infection, hypoxia, and chromosomal abnormalities but is usually of minimal clinical significance. However, there are numerous reports of basal ganglia and thalamic strokes following minor head trauma in children with mineralizing angiopathy. For radiologists, this association is important to recognize and relay to the primary team so targeted history and MRI, if indicated, may be obtained to expedite definitive diagnosis and initiation of treatment to preserve precious brain tissue. Without a history of head trauma, in this case, stroke provocation is unclear, and other infectious or inflammatory disorders could appear similarly if they induced vasospasm or blood pressure lability. A short-interval timeframe between COVID vaccine administration and symptom onset is likely incidental, but research to exclude or illicit any link may be of benefit. Findings of mineralizing angiopathy on CT in the appropriate clinical setting should prompt further evaluation with emergent MRI to determine the presence of basal ganglia or thalamic stroke. Copyright © 2023 Southern Society for Clinical Investigation.

Antimicrobial and Virucidal Potential of Morpholinium-Based Ionic Liquids.

Witnessed by the ongoing spread of antimicrobial resistant bacteria as well as the recent global pandemic of the SARS-CoV-2 virus, the development of new disinfection strategies is of great importance, and novel substance classes as effective antimicrobials and virucides are urgently needed. Ionic liquids (ILs), low-melting salts, have been already recognized as efficient antimicrobial agents with prospects for antiviral potential. In this study, we examined the antiviral activity of 12 morpholinium based herbicidal ionic liquids with a tripartite test system, including enzyme inhibition tests, virucidal activity determination against five model viruses and activity against five bacterial species. The antimicrobial and enzymatic tests confirmed that the inhibiting activity of ILs corresponds with the number of long alkyl side chains and that [Dec2Mor]+ based ILs are promising candidates as novel antimicrobials. The virucidal tests showed that ILs antiviral activity depends on the type and structure of the virus, revealing enveloped Phi6 phage as highly susceptible to the ILs action, while the non-enveloped phages PRD1 and MS2 proved completely resistant to ionic liquids. Furthermore, a comparison of results obtained for P100 and P001 phages demonstrated for the first time that the susceptibility of viruses to ionic liquids can be dependent on differences in the phage tail structure.

Optimization of the expression of the main protease from SARS-CoV-2.

The main protease (Mpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays a vital role in viral replication. To study the function of Mpro and screen inhibitors targeting Mpro, it is necessary to prepare high-purity and high-activity Mpro. In this study, four types of SARS-CoV-2 Mpros containing different termini were prepared, and their activities were determined successfully. The results showed that the activity of wild-type (WT) Mpro was the highest, and the additional residues at the N-terminus but not at the C-terminus had a major effect on the enzyme activity. To explain this, the alignment of structures of different forms of Mpro was determined, and the additional residues at the N-terminus were found to interfere with the formation of the substrate binding pocket. This study confirms the importance of the natural N-terminus to the activity of Mpro and suggests that WT-GPH6 (Mpro with eight additional residues at the C-terminus) can be used as a substitute for authentic Mpro to screen inhibitors. In short, this study provides a reference for the expression and purification of new coronaviruses confronted in the future.