Publications by authors named "Zaven Karalyan"

The spread of the African swine fever virus (ASF virus) genotype ii in the Eurasian region has been very successful and often inexplicable. The virus spreads rapidly and persists in areas with wild boar populations, but areas without feral pig populations are also affected. The virus has shown the ability to survive for a long time in the environment without a population of susceptible hosts, both pigs and Ornithodoros soft ticks.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the antiviral effects of newly synthesized heterocyclic compounds against SARS-CoV-2, aiming to explore their potential as treatment options due to the severity of COVID-19.
  • The research utilized various methods including cell culturing and qRT-PCR to analyze the compounds' effectiveness, showing that they significantly reduced the viral load and improved symptoms in infected hamsters.
  • Results indicated that these compounds not only decreased SARS-CoV-2 replication in vitro but also positively affected pathological changes in hamsters, suggesting their potential for further development as antiviral drugs.
View Article and Find Full Text PDF

Background: The African swine fever (ASF) virus (ASFV) and ASF-like viral sequences were identified in human samples and sewage as well as in different water environments. Pigs regularly experience infections by the ASFV. The considerable stability of the virus in the environment suggests that there is ongoing and long-term contact between humans and the ASFV.

View Article and Find Full Text PDF

Shortly after the establishment of African swine fever virus (ASFV) genotype II in 2007, cases of acute fatal infection were observed. However, after several years of circulation in the Eurasian region, the clinical signs of the disease changed. Currently, this disease can occur acutely, subclinically, chronically, or asymptomatically.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigated viral diseases affecting honey bees in Armenia, focusing on the presence of these viruses in bees, non-bee species, mites, and pollinated plants.
  • A total of 200 bees, 50 mites, and 20 wasps were sampled, revealing the presence of six honey bee viruses, with the most common being deformed wing virus (DWV), acute bee paralysis virus (ABPV), and acute bee norovirus (ANV).
  • Findings suggest that while honey bees carry these viruses, they were also found in wasps and that plants may serve as reservoirs, contributing to the seasonal spread of these viruses.
View Article and Find Full Text PDF

African swine fever virus (ASFV) can accumulate and survive in leeches for a long time. The reasons for the survival of ASFV in leeches are not entirely clear. Here, we elucidate the virus survival pathway in infected leeches.

View Article and Find Full Text PDF

At the end of 2019, an outbreak of a new severe acute respiratory syndrome caused by a coronavirus occurred in Wuhan, China, after which the virus spread around the world. Here, we have described the adaptive capacity and pathogenesis of the SARS-CoV-2 Delta variant, which is widespread in Armenia, in vitro and vivo on Syrian hamsters. We have studied the changes in the SARS-CoV-2genome using viral RNA sequencing during virus adaptation in vitro and in vivo.

View Article and Find Full Text PDF
Article Synopsis
  • African swine fever virus prompts infected G0 cells to transition to the S phase of the cell cycle, only to later halt their progression in the G2 phase.
  • DNA synthesis in the infected cells begins around 10-12 hours post-infection, driven by the activation of specific viral genes linked to nucleotide synthesis and cell cycle regulation.
  • The virus manipulates the cell cycle to exploit the host cell’s resources for nucleotide synthesis, while later interactions with nucleotides reduce the transcriptional activity of genes involved in replication.
View Article and Find Full Text PDF

Anemia is a commonly observed consequence of whole-body exposure to a dose of X-ray or gamma irradiation of the order of the mean lethal dose in mammals, and it is an important factor for the determination of the survival of animals. The aim of this study was to unravel the effect of laser-driven ultrashort pulsed electron beam (UPEB) irradiation on the process of erythropoiesis and the redox state in the organism. rats were exposed to laser-driven UPEB irradiation, after which the level of oxidative stress and the activities of different antioxidant enzymes, as well as blood smears, bone marrow imprints and sections, erythroblastic islets, hemoglobin and hematocrit, hepatic iron, DNA, and erythropoietin levels, were assessed on the 1st, 3rd, 7th, 14th, and 28th days after irradiation.

View Article and Find Full Text PDF

African swine fever virus (ASFV) is a double-stranded DNA virus that causes an acute and hemorrhagic disease in domestic swine, resulting in significant economic losses to the global porcine industry. The lack of vaccines and antiviral drugs highlights the urgent need for antiviral studies against ASFV. Here, we report that brequinar (BQR), which is a specific inhibitor of dihydroorotate dehydrogenase, robustly inhibits ASFV replication in Vero cells, as well as in porcine macrophages.

View Article and Find Full Text PDF

Background And Aim: A drawback of studies on bat blood smears in the field is the lack of time for fixation because blood sampling using a non-lethal method often provides less time for fixation in smear preparations due to the small volume of blood collected. Usually, there is insufficient blood for another smear preparation, so it is necessary to use blood smears as rationally as possible, especially for rare bats. Many stains are used for staining peripheral blood smears, and they have advantages and disadvantages.

View Article and Find Full Text PDF

The water-based combination of two inorganic chemical compounds such as sodium tungstate dihydrate-NaWO × 2HO and Aluminum sulfate octadecahydrate-Al (SO) 3 × 18HO that we have conditionally named 'Vomifal' has a broad antiviral activity in various DNA and RNA viruses, including Human Herpes Virus (HHV), African Swine Fever Virus (ASFV), Vaccinia Virus (VV), Hepatitis C Virus (HCV), Foot and Mouth Disease Virus (FMDV), Influenza A virus (A/Aichi/2/68 (H3N2)). In vitro and In vivo assays in several tissue cultures as well as in laboratory animals, conformed 'Vomifal' has a very low toxicity and the antiviral properties partially are due to its ability to induce gamma-IFN. Based on the results obtained, we can assume the presence of at least two mechanisms of the antiviral action of the studied drug.

View Article and Find Full Text PDF

The development of new laser-driven electron linear accelerators, providing unique ultrashort pulsed electron beams (UPEBs) with low repetition rates, opens new opportunities for radiotherapy and new fronts for radiobiological research in general. Considering the growing interest in the application of UPEBs in radiation biology and medicine, the aim of this study was to reveal the changes in immune system in response to low-energy laser-driven UPEB whole-body irradiation in rodents. Forty male albino rats were exposed to laser-driven UPEB irradiation, after which different immunological parameters were studied on the 1st, 3rd, 7th, 14th, and 28th day after irradiation.

View Article and Find Full Text PDF

Naturally occurring plant flavonoids are a promising class of antiviral agents to inhibit African swine fever virus (ASFV), which causes highly fatal disease in pigs and is a major threat to the swine industry. Currently known flavonoids with anti-ASFV activity demonstrate a wide range of antiviral mechanisms, which motivates exploration of new antiviral candidates within this class. The objective of this study was to determine whether other flavonoids may significantly inhibit ASFV infection .

View Article and Find Full Text PDF

Recently, a new technology of low-energy ultrashort-pulsed electron beam (UPEB) accelerators has been developed opening new directions for radiobiology and biomedical research. The purpose of this study was to reveal the lethal dose, LD50 (lethal dose, 50%) delivered by low-energy UPEB whole-body exposure on an organismal level. Wistar rats were exposed to low-energy UPEB whole-body irradiation with different doses and pulse repetition rates to find the LD50 and in silico computer simulations were performed to conduct numerical dose calculations.

View Article and Find Full Text PDF

Background And Aim: In modern scientific literature presents an understanding that African swine fever (ASF) ASF virus (ASFV) is remarkably stable in the environment, and carcasses of the pigs which were died after ASF, play a key role as ASFV reservoir. The aim of this study was to evaluate the possibility of the ASFV (different isolates) survival in bodies of dead animals, bones, remnants of bone marrow, residual organ matrix in natural conditions.

Materials And Methods: Skeletons of ASFV infected pigs which were died and left/abandoned in forests or buried in Armenia at diverse time points and locations had been excavated and examined for the presence of ASFV genome by real-time polymerase chain reaction (PCR) assay and for infection abilities through (hemadsorption test and infection in porcine lung macrophages) as well as by intramuscular infection in healthy pigs.

View Article and Find Full Text PDF

African swine fever virus (ASFV) is the causal agent of a fatal disease of domestic swine for which no effective antiviral drugs are available. Recently, it has been shown that microtubule-targeting agents hamper the infection cycle of different viruses. In this study, we conducted in silico screening against the colchicine binding site (CBS) of tubulin and found three new compounds with anti-ASFV activity.

View Article and Find Full Text PDF

Aim: A genome-scale phylogenetic analysis was used to infer the evolutionary dynamics of - African swine fever virus (ASFV) - and better define its genetic diversity.

Materials And Methods: All complete ASFV genomes from NCBI's resource as of March 2020 were used. The phylogenetic analysis used maximum likelihood and neighbor-joining methods.

View Article and Find Full Text PDF
Article Synopsis
  • The study examined how two strains of African swine fever (ASF) viruses affect the activation of porcine alveolar macrophages (AM), noting differences in immune response.
  • Cells infected with the virulent ASFV-Georgia2007 showed unique M1 polarization and changes in morphology, resulting in lower synthesis of certain interferons compared to those infected with the attenuated strain ASFV-BA71V.
  • The findings suggest that the more virulent ASFV-Georgia2007 reduces the antiviral response of AM, indicating that the evolutionary decrease of ASFV virulence is linked to changes in host immune system regulation.
View Article and Find Full Text PDF

Aim: The aim of this research was to study the effect of rabbit hemorrhagic disease virus (RHDV) on the host immune response by examining the cellular composition/pathology of lymphoid organs and serum levels of tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ).

Materials And Methods: Nine adult rabbits were inoculated with 1 ml of 10% infected liver homogenate, and three rabbits served as controls. The rabbit hemorrhagic disease (RHD)-induced animals were studied on 3 consecutive days post-infection.

View Article and Find Full Text PDF

African swine fever virus (ASFV) is the causative agent of an economically important disease of pigs for which no effective vaccines or antiviral drugs are available. Recent outbreaks in EU countries and China have highlighted the critical role of antiviral research in combating this disease. We have previously shown that apigenin, a naturally occurring plant flavone, possesses significant anti-ASFV activity.

View Article and Find Full Text PDF

Glomerulonephritis due to African swine fever (ASF) is well documented. However, there is absence of good understanding of mechanisms involved in the development of pathology development. This study examines glomerulonephritis in association with acute infection induced by II genotype (Georgia 2007) of ASF virus.

View Article and Find Full Text PDF

The present study describes the gross, histopathologic lesions of the heart arising in pigs infected with acute African Swine Fever (ASF) and their biochemical profile. Ten pigs were infected by intramuscular injection of ASF virus (Georgia 2007). Selected heart samples were submitted for histopathological examination and Hematoxylin-Basic Fuchsin-Picric Acid (HBFP) staining.

View Article and Find Full Text PDF

African swine fever virus (ASFV) is the causal agent of a highly-contagious and fatal disease of domestic pigs, leading to serious socio-economic consequences in affected countries. Once, neither an anti-viral drug nor an effective vaccines are available, studies on new anti-ASFV molecules are urgently need. Recently, it has been shown that ASFV type II topoisomerase (ASFV-topo II) is inhibited by several fluoroquinolones (bacterial DNA topoisomerase inhibitors), raising the idea that this viral enzyme can be a potential target for drug development against ASFV.

View Article and Find Full Text PDF

The brains of 10 infected pigs were examined for histopathology and presence of African swine fever virus (ASFV) DNA ASFV infection induces inflamed meninges, cerebral edema and vascular thrombosis, as well as subdural hematomas. Slight tension in the dura mater, flattening of the gyri and narrowing of the sulci were also observed at four days post infection (dpi). Enlarged perivascular spaces were detected for most vessels of the brain after three to four dpi.

View Article and Find Full Text PDF