Publications by authors named "Radka Argirova"

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), a pneumonia with extremely heterogeneous clinical presentation, ranging from asymptomatic to severely ill patients. Previous studies have reported links between the presence of host genetic variants and the outcome of the COVID-19 infection. In our study, we used whole exome sequencing in a cohort of 444 SARS-CoV-2 patients, admitted to hospital in the period October-2020-April-2022, to search for associations between rare pathogenic/potentially pathogenic variants and COVID-19 progression.

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Objective: This study focused on Bulgarian patient cohorts harbouring a single documented chronic comorbidity-cardiovascular pathology, an oncological disease or a chronic pulmonary diseases (CPD) comparing the outcomes in fully vaccinated and non-vaccinated populations classified by sex and age groups in ambulatory, hospital and intensive care unit (ICU) settings at the national level.

Design: Retrospective analysis SETTINGS, PARTICIPANTS AND OUTCOME MEASURES: In total, 1 126 946 patients with confirmed COVID-19, on a national level, were retrospectively analysed between March 2020 and April 2022, using data from the Ministry of Health's United Information Portal, launched in March 2020.

Results: Of all the confirmed 247 441 hospitalised cases of COVID-19, 67 723 (27.

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Monkeypox (Mpox) is an emerging viral disease caused by the monkeypox virus (MPXV), a double-stranded DNA virus member of the genus Orthopoxvirus, first reported in humans in 1970. Since May 2022, a global spread of the infection has occurred that the World Health Organization (WHO) declared a public health emergency. In view of the global threat, efforts have been devoted to bolstering the disease spread as well as identifying viable therapeutic modalities.

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Drugs Armenicum and FS-1 are a solution of ionic nanostructured complexes of α-dextrin. In the active centers of these drugs, located inside the dextrin helix, molecular iodine has such an electronic form that minimizes toxic effects in the human body, so these drugs can be used for parenteral and oral administration. On the human lymphoblastoid cell line MT-2, the effect of the antiviral action of FS-1 against HIV-1 was established.

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Epstein-Barr virus is a widely spread Herpesvirus. Primary EBV infection affects children and young people, inducing haematological changes, with lymphocytosis being the most common. Moderate symptomless thrombocytopenia is found in 50% of the patients, however, severe thrombocytopenia is exceptionally rare.

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Peptidomimetic inhibitors of HIV-1 PR are still a key resource in the fight against AIDS. Here we describe the synthesis and biological activity of HIV-1 PR inhibitors based on four novel dihydroxyethylene isosteres of the Phe-Pro and Pro-Pro dipeptides. The isosteres, containing four stereogenic centers, were synthesized in high yield and excellent stereoselectivity via the cyclization of epoxy amines derived from α-amino acids.

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Six novel 4-hydroxycoumarin derivatives were rationally synthesized, verified, and characterized by molecular docking using crystal HIV-1 protease. Molecular docking studies predicted antiprotease activity of (7) and (10). The most significant functional groups, responsible for the interaction with HIV-1 protease by hydrogen bonds formation are pyran oxygen, atom, lactone carbonyl oxygen and one of the hydroxyl groups.

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Host and/or viral factors involved in human polyomavirus (HPoV) infection in persons living with HIV remain unknown. A hypothesis is outlined suggesting the importance of the co-receptors CCR5, CCR2, and CXCR4 not only for HIV, but also for HPoV. Functionally capable receptors coded by wild-type (wt) genotypes could facilitate internalization of HPoV in the cell resulting in brain and/or kidney infection/s in HIV infected individuals.

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The cytotoxicity and the antivirus activity of native hemocyanin, RtH, derived from the Bulgarian marine mollusk Rapana thomasiana and its structural isoform, RtH2, against HSV replication was evaluated on three HSV strains--two wt strains, TM (HSV 1) and Bja (HSV 2), and one ACVR mutant with tk gene mutation, DD (HSV 2). The experiments were performed on continuous RD 64 cells and three HSV 1 and HSV 2 strains were used, two mutants sensitive to acyclovir and one resistant mutant. Both compounds were found to be effective inhibitors of wt HSV replication.

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The cerium Ce(III), lanthanum La(III), and neodymium Nd(III) complexes with 4-hydroxy-3-(3-oxo-1-phenylbutyl)-2H-1-benzopyran-2-one (warfarin) (W) and 3,3'-benzylidenebis[4-hydroxycoumarin] (1) were synthesized and studied for the first time for cytotoxicity (on MT-2 cells) and as anti-HIV agents under acute and chronic infection. The complexes were characterized by different physicochemical methods: mass spectrometry, (1)H NMR, (13)C NMR, and IR spectroscopy. The spectra of the complexes were interpreted on the basis of comparison with the spectrum of the free ligands.

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