DNA Damage in Moderate and Severe COVID-19 Cases: Relation to Demographic, Clinical, and Laboratory Parameters.

The ability of the SARS-CoV-2 virus to cause DNA damage in infected humans requires its study as a potential indicator of COVID-19 progression. DNA damage was studied in leukocytes of 65 COVID-19 patients stratified by sex, age, and disease severity in relation to demographic, clinical, and laboratory parameters. In a combined group of COVID-19 patients, DNA damage was shown to be elevated compared to controls (12.

Changes in Telomere Length in Leukocytes and Leukemic Cells after Ultrashort Electron Beam Radiation.

Application of laser-generated electron beams in radiotherapy is a recent development. Accordingly, mechanisms of biological response to radiation damage need to be investigated. In this study, telomere length (TL) as endpoint of genetic damage was analyzed in human blood cells (leukocytes) and K562 leukemic cells irradiated with laser-generated ultrashort electron beam.

The Diagnostic, Prognostic, and Therapeutic Potential of Cell-Free DNA with a Special Focus on COVID-19 and Other Viral Infections.

Cell-free DNA (cfDNA) in human blood serum, urine, and other body fluids recently became a commonly used diagnostic marker associated with various pathologies. This is because cfDNA enables a much higher sensitivity than standard biochemical parameters. The presence of and/or increased level of cfDNA has been reported for various diseases, including viral infections, including COVID-19.

Application of land snail Helix lucorum for evaluation of genotoxicity of soil pollution.

Application of native species as sentinels allows environmental scientists to determine real genotoxic impact of environmental pollutants. The present study aims at investigating the DNA damage in the land snail Helix lucorum as a biomarker of soil pollution. For this reason, the genotoxic impact of contaminated soil on H.

Doxorubicin-Induced Translocation of mtDNA into the Nuclear Genome of Human Lymphocytes Detected Using a Molecular-Cytogenetic Approach.

Translocation of mtDNA in the nuclear genome is an ongoing process that contributes to the development of pathological conditions in humans. However, the causal factors of this biological phenomenon in human cells are poorly studied. Here we analyzed mtDNA insertions in the nuclear genome of human lymphocytes after in vitro treatment with doxorubicin (DOX) using a fluorescence in situ hybridization (FISH) technique.

DNA Copy Number Variations as Markers of Mutagenic Impact.

DNA copy number variation (CNV) occurs due to deletion or duplication of DNA segments resulting in a different number of copies of a specific DNA-stretch on homologous chromosomes. Implications of CNVs in evolution and development of different diseases have been demonstrated although contribution of environmental factors, such as mutagens, in the origin of CNVs, is poorly understood. In this review, we summarize current knowledge about mutagen-induced CNVs in human, animal and plant cells.

Application of the comet assay, micronucleus test and global DNA methylation analysis in Darevskia lizards as a sentinel organism for genotoxic monitoring of soil pollution.

Widely distributed in Armenia bisexual and parthenogenetic species of Darevskia rock lizards have the potential to be considered as bioindicators of the effects of environmental pollutants. Juvenile and adult bisexual D. raddei and parthenogenetic D.

Analysis of copy number variations induced by ultrashort electron beam radiation in human leukocytes in vitro.

Background: Environmental risk factors have been shown to alter DNA copy number variations (CNVs). Recently, CNVs have been described to arise after low-dose ionizing radiation in vitro and in vivo. Development of cost- and size-effective laser-driven electron accelerators (LDEAs), capable to deliver high energy beams in pico- or femtosecond durations requires examination of their biological effects.

DNA damage and micronuclei in parthenogenetic and bisexual Darevskia rock lizards from the areas with different levels of soil pollution.

Natural species are widely used as indicator organisms to estimate of the impact of environmental pollution. Here we present the results of first study of a reliability of parthenogenetic Darevskia аrmeniaca and bisexual Darevskia raddei rock lizards as sentinels for monitoring of environmental genotoxicity. The comet assay and micronucleus test were applied to the lizards sampled in six areas in Armenia and Artsakh with different levels of soil contamination.

Dose-rate effect of ultrashort electron beam radiation on DNA damage and repair in vitro.

Laser-generated electron beams are distinguished from conventional accelerated particles by ultrashort beam pulses in the femtoseconds to picoseconds duration range, and their application may elucidate primary radiobiological effects. The aim of the present study was to determine the dose-rate effect of laser-generated ultrashort pulses of 4 MeV electron beam radiation on DNA damage and repair in human cells. The dose rate was increased via changing the pulse repetition frequency, without increasing the electron energy.

A New Case of a Complex Small Supernumerary Marker Chromosome: A Der(9)t(7;9)(p22;q22) due to a Maternal Balanced Rearrangement.

Complex small supernumerary marker chromosomes (sSMCs) constitute one of the smallest subsets within the patients with an sSMC. Complex sSMCs consist of chromosomal material derived from more than one chromosome, for example, the derivative der(22)t(11;22)(q23;q11.2) in Emanuel syndrome.

Comparative analysis of individual chromosome involvement in micronuclei induced by mitomycin C and bleomycin in human leukocytes.

Background: Micronucleus (MN) assay is a well standardized approach for evaluation of clastogenic/aneugenic effects of mutagens. Fluorescence in situ hybridization (FISH) is successfully used to characterize the chromosomal content of MN. However, the relationships between nuclear positioning, length, and gene density of individual chromosomes and their involvement in MN induced by different mutagens have not been clearly defined.

Genotoxicity of Water Contaminants from the Basin of Lake Sevan, Armenia Evaluated by the Comet Assay in Gibel Carp (Carassius auratus gibelio) and Tradescantia Bioassays.

Combination of bioassays and chemical analysis was applied to determine the genotoxic/mutagenic contamination in four different sites of the basin of Lake Sevan in Armenia. Water genotoxicity was evaluated using the single cell gel electrophoresis technique (comet assay) in erythrocytes of gibel carp (Carassius auratus gibelio), Tradescantia micronucleus (Trad-MCN) and Tradescantia stamen hair mutation (Trad-SHM) assays. Significant inter-site differences in the levels of water genotoxicity according to fish and Trad-MCN bioassays have been revealed.

Influence of aflatoxin B1 on copy number variants in human leukocytes in vitro.

Background: Aflatoxin B1 (AFB1) is a mycotoxin produced by Aspergillus spec. The latter are worldwide contaminants of food with mutagenic and carcinogenic activities in animals and humans. AFB1 was shown to have deleterious effects on metabolism of eukaryotes in many model systems, including the ability to inhibit DNA replication.

Chromosomal composition of micronuclei in human leukocytes exposed to mitomycin C.

Micronuclei (MN) can be induced by different mutagenic substances. Even though this has been known for decades, it is still not clear which genetic content, especially which chromosomes, these MN are constituted of and if there are any influences on this content by the MN-inducing substance. Also, the interphase position, size, and gene density of a chromosome could influence its involvement in MN formation.

Fluorescence in situ hybridization in combination with the comet assay and micronucleus test in genetic toxicology.

Comet assay and micronucleus (MN) test are widely applied in genotoxicity testing and biomonitoring. While comet assay permits to measure direct DNA-strand breaking capacity of a tested agent MN test allows estimating the induced amount of chromosome and/or genome mutations. The potential of these two methods can be enhanced by the combination with fluorescence in situ hybridization (FISH) techniques.

Butyrate reduces the frequency of micronuclei in human colon carcinoma cells in vitro.

Butyrate, formed by bacterial fermentation of plant foods, has been shown to protect human colon cells from selected genotoxic substances. The mechanism for this effect could be the enhancement of toxicological defence leading to an increased detoxification of genotoxic risk factors and thus to a reduction of DNA and chromosome damage. Previous protective properties of butyrate against DNA damage induction in colon cells were demonstrated using the comet assay.

Use of Comet-FISH in the study of DNA damage and repair: review.

The Comet-FISH technique is a useful tool to detect overall and region-specific DNA damage and repair in individual cells. It combines two well-established methods, the Comet assay (single cell gel electrophoresis) and the technique of fluorescence in situ hybridization (FISH). Whereas the Comet assay allows separating fragmented from non-fragmented DNA, FISH helps to detect specifically labelled DNA sequences of interest, including whole chromosomes.

In vitro testing of cyto- and genotoxicity of new porphyrin water-soluble metal derivatives.

Porphyrins and porphyrin derivatives have an outstanding potential for discovery of novel pharmacological agents due to their ability for numerous chemical modifications and a variety of mechanisms of biological effects. New water-soluble Ag and Zn derivatives of tetrachloride meso-tetra (4-N-oxiethylpyridyl) porphyne were synthesized. Cyto- and genotoxicity of these substances were tested in vitro by the vital dye (trypan blue) exclusion and the micronucleus tests, respectively.

Fragility of telomeres after bleomycin and cisplatin combined treatment measured in human leukocytes with the Comet-FISH technique.

Unlabelled: THE AIM of the present study was the comparative investigation of action of widely applied anticancer preparations: cisplatin (cis-DDP) and bleomycin (BLM) on total DNA and telomeres damage in human blood cells.

Methods: The "Comet-FISH technique" -- single cell gel electrophoresis ("comet assay") in combination with fluorescent in situ hybridization (FISH) was used for this purpose. This newly applied combined approach permits to detect on the same specimen the total DNA damage in individual cells and evaluate specific DNA sequences as well.

Evaluation of cisplatin-DNA crosslinks formation with UV-C application by the alkaline Comet-assay.

Unlabelled: The AIM of the present study was to investigate DNA damage induced by widely applied anticancer preparation cisplatin (cis-DDP) at doses comparable with therapeutic ones in leukocytes of healthy donors.

Methods: DNA damage and repair was estimated by the single cell gel electrophoresis or Comet-assay. For estimation of cis-DDP-induced DNA crosslinks the combined treatment by cis-DDP with the DNA damaging agent UV-C was used.

Comet-FISH using peptide nucleic acid probes detects telomeric repeats in DNA damaged by bleomycin and mitomycin C proportional to general DNA damage.

For the optimal use of anticancer drugs a knowledge of the whole spectrum of side-effects is required. A potential hazard, so far only scarcely investigated, is uncontrolled effects of drugs such as bleomycin (BLM) and mitomycin C (MMC) on telomere shortening in non-cancerous tissues of the treated person. For the first time, directly labelled telomere-specific peptide nucleic acid (PNA) hybridization probes were applied in comet-FISH to detect DNA fragmentation on an intermediate scale.