Significant Difference In DNA Damage Research Articles

Are patients with severe obesity aging faster? The impact of severe obesity on different aspects of biological age.

Obesity and aging are characterized by chronic low-grade inflammation, which contributes to the onset of degenerative processes. The objective was to comprehensively analyze the prevalence of premature aging in obesity and identify metabolic factors influencing aging. In this prospective cohort study, the telomere length, 8-Oxo-2'-deoxyguanosine DNA damage, interleukin-6 (IL-6), metabolic age and cognitive functions were evaluated in the patients with severe obesity (study group (SG), defined as BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with comorbidities, n=100) and the healthy volunteers (control group (CG), defined as BMI 18.5 - 24.9 kg/m2, n=33). SG was further divided into two subgroups: study group 1 (SG1) - subjects with BMI≥ 50 kg/m2and study group 2 (SG2) with BMI < 50 kg/m2. Our findings revealed that individuals in the SG exhibited shorter telomeres, higher levels of inflammation, and more advanced metabolic age compared to those in the CG. However, no significant differences in DNA damage or cognitive function abilities were observed between the SG and CG. Notably, SG1 displayed elevated IL-6 levels compared to SG2. Furthermore, IL-6 levels decreased significantly with increasing body fat, and individuals with higher visceral fat levels had longer telomeres. Premature aging manifests in obesity concerning telomere length, inflammation levels and metabolic age. Aging in obesity should be considered as a non-linear process.

Exploring the Relationship Between Genetic Instability and Health Outcomes in Acute and Chronic Post-COVID Syndrome.

The COVID-19 pandemic has led to the emergence of acute and chronic post-COVID syndromes, which present diverse clinical manifestations. The underlying pathophysiology of these conditions is not yet fully understood, but genetic instability has been proposed as a potential contributing factor. This study aimed to explore the differential impact of physical and psychological health factors on genetic instability in individuals with acute and chronic post-COVID syndromes. In this study, three groups of subjects were analyzed: a control group, an acute post-COVID group, and a chronic post-COVID group, with a total of 231 participants. The participants were assessed using a questionnaire for long-COVID-19COVID, and female participants reported more symptoms than male participants in areas related to fatigue, memory, mental health, and well-being during the chronic phase. Genetic instability was assessed using the comet assay, and participants' physical and psychological profiles were evaluated. The overall results showed no significant differences in DNA damage, as measured by the comet assay, among the three groups, suggesting that genetic instability, as assessed by this method, may not be a primary driver of the distinct clinical presentations observed in post-COVID syndromes. However, when gender was considered, male participants in the acute long COVID group exhibited higher levels of genetic instability compared to females. Multiple linear regression analysis revealed that gender, age, and waist circumference were significant predictors of DNA damage. Among females in the acute group, sexual health, and eye-related symptoms significantly influenced the increase in DNA damage. These findings indicate the need for further investigation on the gender-specific differences in genetic instability and their potential implications for the pathophysiology of post-COVID syndromes. Exploring alternative markers of genetic instability and the interplay between genetic, inflammatory, and cellular processes could provide valuable insights for the management of these debilitating post-viral sequelae.

Comparing P53 expression and genome-wide transcriptome profiling to Comet assay in lymphocytes from melanoma patients and healthy controls.

This study compared the expression of TP53 in lymphocytes from malignant melanoma (MM) patients with positive sentinel nodes to healthy controls (HCs) following exposure to various doses of UVA radiation. The Lymphocyte Genome Sensitivity (LGS) assay indicated significant differences in DNA damage in lymphocytes between MM patients and HCs. qPCR data demonstrated an overall 3.4-fold increase in TP53 expression in lymphocytes from MM patients compared to healthy controls, following treatment with 0.5 mW/cm2 UVA radiation. Western blotting confirmed that p53 expression was increased in MM lymphocytes following UVA exposure compared to healthy individuals. Genome transcriptome profiling data displayed differences in gene expression between UVA-treated lymphocytes from MM patients and HCs. Peripheral lymphocytes from MM patients are more susceptible to the genotoxic effects of UVA compared to healthy individuals. Our previous studies showed that UVA exposure of various intensities caused significant differences in the levels of DNA damage between lymphocytes from cancer patients compared to HCs through the LGS assay. The present study's results provide further credibility to the LGS assay as a screening test for cancer detection. Peripheral lymphocytes could be a promising blood biopsy biomarker for staging of carcinomas and prevention of carcinoma progression at early stages.

Investigation Of Genotoxic Effect Of Octyl Gallate Used As An Antioxidant Food Additive In In Vitro Test Systems.

Several antioxidant food additives are added to oils, soups, sauces, chewing gum, potato chips etc. One of them is octyl gallate. The purpose of this study was to evaluate the potential genotoxicity of octyl gallate in human lymphocytes, using in vitro chromosomal abnormalities (CA), sister chromatid exchange (SCE), cytokinesis block micronucleus cytome (CBMN-Cyt), micronucleus-FISH (MN-FISH), and comet tests. Different concentrations (0.50, 0.25, 0.125, 0.063, and 0.031 μg/mL) of octyl gallate were used. A negative (distilled water), a positive (0.20 μg/mL Mitomycin-C), and a solvent control (8.77 μL/mL ethanol) were also applied for each treatment. Octyl gallate did not cause changes in chromosomal abnormalities, micronucleus, nuclear bud (NBUD) and nucleoplasmic bridge (NPB) frequency. Similarly, there was no significant difference in DNA damage (comet assay), percentage of centromere positive and negative cells (MN-FISH test) compared to the solvent control. Moreover, octyl gallate did not affect replication and nuclear division index. On the other hand, it significantly increased the SCE/cell ratio in three highest concentrations compared to solvent control at 24h treatment. Similarly, at 48h treatment, the frequency of SCE raised significantly compared to solvent controls at all the concentrations (except 0.031 μg/mL). An important reduce was detected in mitotic index values in highest concentration at 24h treatment and almost all concentrations (except 0.031 and 0.063 µg / mL) at 48h treatment. The results obtained suggest that octyl gallate has no an important genotoxicological action on human peripheral lymphocytes at the concentrations applied in this study.

Does storage conditions of whole blood or blood cells effect genotoxicity assessment by comet assay?

Comet assay, applied to in vitro, in vivo and ex vivo systems, is a quick, simple, and sensitive method for the detection of genotoxicity. In general, fresh whole blood or peripheral blood mononuclear cells (PBMCs) are used in the assay for the determination of DNA damage and repair. In this study, the effects of storage conditions on genotoxicity assessed by Comet assay in human whole blood and lymphocyte samples, were evaluated. Whole blood and lymphocyte samples were stored at 4 °C for 1, 2, 3, 4, 5 and 7 days; at −20 °C for 1 month and at −80 °C for 3, 6 and 12 months. 1% DMSO was used as cryoprotectant. No significant differences in DNA damage were demonstrated in all of the storage conditions and durations, and the results were similar according to the median values (p < 0.05). According to Spearman or Pearson correlations, an important correlation was found between the DNA damage of the fresh samples and the samples which were kept at −80 °C for 6 months with temperature and time (p < 0.01 for Pearson and p < 0.05 for Spearman). The results of this study indicated that blood and lymphocyte samples stored in +4 °C, −20 °C and −80 °C up to 12 months can be used instead of fresh samples especially in human biomonitoring studies.

Environmental radiation on large Japanese field mice in Fukushima reduced colony forming potential in hematopoietic progenitor cells without inducing genomic instability

Purpose To study the environmental radiation effects of wild animals after the Fukushima Dai-ichi nuclear power plant accident, we assessed effects on hematopoietic progenitor cells (HPCs) in large Japanese field mice (Apodemus speciosus). Materials and methods A. speciosus were collected from three contaminated sites and control area. The air dose-rates at the control and contaminated areas were 0.96 ± 0.05 μGy/d (Hirosaki), 14.4 ± 2.4 μGy/d (Tanashio), 208.8 ± 31.2 μGy/d (Ide), 470.4 ± 93.6 μGy/d (Omaru), respectively. We investigated possible DNA damage and pro-inflammatory markers in the bone marrow (BM) cells. The colony-forming potential of BM cells was estimated by the number of HPC colony-forming cells. Radiation-induced genomic instability (RIGI) in HPCs was also analyzed by quantifying delayed DNA damage in CFU-GM clones. Results Although no significant differences in DNA damage and inflammation markers in BM cells from control and contaminated areas, the number of HPC colonies exhibited an inverse correlation with air dose-rate. With regard to RIGI, no significant differences in DNA damage of CFU-GM clones between the mice from the control and the three contaminated areas. Conclusions Our study suggests that low dose-rate radiation of more than 200 Gy/d reduced HPCs, possibly eliminating genomically unstable HPCs.

Impacts of phototherapy on DNA damage and total oxidant/ antioxidant status in jaundiced newborns.

Bulut Ö, Dürüyen S. Impacts of phototherapy on DNA damage and total oxidant/antioxidant status in jaundiced newborns. Turk J Pediatr 2019; 61: 697-703. Jaundice is common in newborn babies, and pathologic hyperbilirubinemia is frequently treated with phototherapy. Although it is considered to be safe, the side effects of phototherapy in newborns are still a matter of debate. In this study, the impacts of two types of phototherapy, conventional fluorescence and intensive light-emitting diodes (LED), on DNA damage and total oxidant/ antioxidant status in jaundiced newborns were assessed. The study group included 40 newborns (gestation age ≥ 37 weeks) on days 2-8 after birth. Newborns were divided into two groups on the basis of need for phototherapy: 20 newborns were exposed to conventional phototherapy (Group I); and 20 infants were exposed to intensive phototherapy (Group II). Blood samples were taken from all infants at admission and after phototherapy to determine plasma 8-hydroxy-2-deoxy-guanosine (8-OH-dG; a marker of DNA damage), total oxidant status (TOS), and total antioxidant capacity (TAC). The oxidative stress index (OSI) was also calculated. Demographic information was recorded, and DNA damage, TOS, and TAC were compared. There were no differences in demographic information between the two groups. There were no significant differences in DNA damage, TOS, TAC, and OSI between Groups I and II before phototherapy (p > 0.05) and no significant differences in DNA damage, TOS, TAC, and OSI between the two groups after phototherapy (p > 0.05). However, the TAC decreased significantly in both groups after phototherapy (p < 0.01). These findings suggest that conventional and intensive phototherapies do not affect DNA damage and oxidative stress, supporting the safety of its use as the preferred treatment for jaundiced newborns.

How Does Infection with Human Papillomavirus 16 and 18 Impact on DNA Damage and Repair in Cervical Cells and Peripheral Blood?

Human papillomavirus (HPV) infection is one of the most common sexually transmitted diseases worldwide and a prime cause of cervical cancer. The HPV DNA is detected in approximately 80-90% of all cervical cancers, with HPV 16 and 18 being the high risk conferring human carcinogens. DNA damage and diminished DNA repair mechanisms are potential biological surrogates of HPV infection that warrant further research in different tissues and populations. Notably, we do not know the extent to which the high risk HPV 16 and 18 differentially affect cervical cells versus other systems such as peripheral blood lymphocytes (PBLs). We evaluated DNA damage and repair in women who tested positive for HPV 16 or HPV 18 and healthy control women without HPV 16 or HPV 18 infection. We found that the DNA damage as measured by the Comet assay was markedly greater in cervical cells of women with HPV 16 (mean: 8.1 as% DNA in tail, 95% CI: 7.6-8.7) or HPV 18 infection (mean: 9.6, 95% CI: 8.9-10.2) than controls (mean: 6.7, 95% CI: 6.2-7.4) (p < 0.05). By contrast, in PBLs, we did not find a significant difference in DNA damage between women with HPV 16 or 18 infection versus controls, as measured by the Comet assay or the Conventional Chromosomal Aberration analysis (p > 0.05). We observed, however, the DNA repair capacity, as measured by the X-ray induced challenge (XRC) assay, was significantly impaired in PBLs from women with HPV 16 or 18 infection compared to controls (p < 0.05). This is the first comparative study, to the best of our knowledge, suggesting that the cervical swab cells might be better suited than peripheral lymphocytes as biosamples for detection of HPV 16 or 18 biological effects on DNA damage. In addition, these findings suggest that the Comet assay performed only in PBLs may potentially lead to false negative diagnosis of DNA damage. Taken together, these observations contribute to development of future diagnostic innovation and precision sampling strategies for robust detection of the biological effects of HPV 16 or 18 in women. We conclude by a brief discussion of implications for HPV clinical diagnostics and precision medicine innovation.

Backtracked analysis of preleukemic fusion genes and DNA repair foci in umbilical cord blood of children with acute leukemia.

The first event in origination of many childhood leukemias is a specific preleukemic fusion gene (PFG) that arises, often in utero, in hematopoietic stem/progenitor cells (HSPC) from misrepaired DNA double strand break (DSB). An immanently elevated level of DSB and impaired apoptosis may contribute to origination and persistence of PFG and donor cell-derived leukemia in recipients of allogeneic transplantation of umbilical cord blood (UCB). We investigated DSB, apoptosis and PFG in the backtracked UCB cells of leukemic patients. RNA from UCB of three patients with acute lymphoblastic leukemia, patient with acute megakaryoblastic leukemia and Down syndrome, and four healthy children was screened for common PFG by RT-qPCR. Presence of PFG was validated by sequencing. Endogenous γH2AX and 53BP1 DNA repair foci, cell populations, and apoptosis were analyzed in UCB CD34+/- cells with imaging and standard flow cytometry. We found MLL2-AF4 and BCR-ABL (p190) fusion genes in UCB of two out from four pediatric patients, apparently not detected at diagnosis, while UCB cells of TEL-AML1+ ALL patient were tested negative for this PFG and no PFG were detected in UCB cells of healthy children. No significant difference in DNA damage and apoptosis between UCB CD34+/- cells from healthy children and leukemic patients was observed, while Down syndrome trisomy increased DNA damage and resulted in distribution of cell populations resembling transient abnormal myelopoiesis. Our findings indicate increased genetic instability in UCB HSPC of leukemic patients and may be potentially used for diagnostics and exclusion of possibly affected UCB from transplantation.

Genotoxicity of recycled electronic waste in Idhna, Hebron District, occupied Palestinian territory: a case-controlled study

BackgroundElectronics waste is solid waste that accumulates because of the short lifespan of many types of electronic equipment. Most electronics waste ends up in landfills, whereas some is recycled. In the occupied Palestinian territory, the village of Idhna in the Hebron District is a large site for recycling electronics waste (much of this waste originates from Israel). The aim of this study was to evaluate the effects of electronics waste on human DNA damage and chromosome breaks. MethodsIn this cross-sectional study, we recruited non-smoker individuals with direct exposure to electronics waste either because they were employed in the workshops or resident in Idhna. Control participants were selected to match the test sample in age and sex distribution, were recruited from Bethlehem and Al-Aizariya (Bethany). Blood samples in sodium heparin were evaluated for DNA damage using the COMET assay, whereas chromosome aberrations were tested by using conventional cytogenetic techniques. Findings46 participants were included in the test sample, and 16 participants were included in the control sample. Participants in the test sample had an average of 3·77 chromosomes with aberrations (SD 2·5), whereas participants in the control group had an average of 0·75 chromosomes with aberrations (SD 0·61). The frequency of chromatid and chromosome breaks, formation of rings, and total chromosome aberrations was statistically different between exposed and control samples, but no difference was observed between exposed and controls for the incidence of dicenterics and tetraploidy. Results of the Comet assay showed a significant difference in DNA damage between exposed and control participants (p<0·05). No difference between the workers and the residents living in the area was noted (p<0·05). InterpretationExposure to recycled electronics waste in Idhna has potentially adverse health consequences. This is the second study of this kind in the occupied Palestinian territories. Hammad and Qumsiyeh (2013) have previously shown substantial genotoxic effects of Israeli industrial settlement discharge on human populations in Salfit (northern West Bank). Considering increased incidence of cancer and congenital birth defects in the southern part of the West Bank, these findings were important in promoting the case for mitigation measures, which are now under way. FundingNone.

Genotoxicity in adult residents in mineral coal region-a cross-sectional study.

The present study assessed the DNA damage in environmentally exposed volunteers living in seven municipalities in an industrial coal region, through the use of the comet assay with blood cells and the micronucleus test with buccal cells. Blood and buccal smears were collected from 320 male volunteers living in seven cities inserted in a coal region. They were ages of 18 and 50years and also completed a questionnaire intended to identify factors associated with DNA damage through a Poisson regression analysis. The comet assay detected significant differences in DNA damage in volunteers from different municipalities, and neighboring cities (Pedras Altas, Aceguá, and Hulha Negra) had a higher level of DNA damage in relation to control city. Some of the risk factors associated with identified DNA lesions included residence time and life habits. On the other hand, the micronucleus test did not identify differences between the cities studied, but the regression analysis identified risk factors such as age and life habits (consumption of mate tea and low carbohydrates diet). We conclude that there are differences in the DNA damage of volunteers from different cities of the carboniferous region, but the presence of micronuclei in the oral mucosa does not differ between the same cities. Furthermore, we alert that some related factors may increase the risk of genotoxicity, such as residence location and time, and living and food habits. Finally, we suggest the need for continuous biomonitoring of the population, as well as for investing in health promotion in these vulnerable populations.

Neurotoxicity of low bisphenol A (BPA) exposure for young male mice: Implications for children exposed to environmental levels of BPA

To investigate the neuron toxicities of low-dose exposure to bisphenol A (BPA) in children, mice were used as an animal model. We examined brain cell damage and the effects of learning and memory ability after BPA exposure in male mice (4 weeks of age) that were divided into four groups and chronically received different BPA treatments for 8 weeks. The comet assay and hippocampal neuron counting were used to detect the brain cell damage. The Y-maze test was applied to test alterations in learning and memory ability. Long term potentiation induction by BPA exposure was performed to study the potential mechanism of performance. The percentages of tail DNA, tail length and tail moment in brain cells increased with increasing BPA exposure concentrations. Significant differences in DNA damage were observed among the groups, including between the low-dose and control groups. In the Y-maze test, the other three groups qualified for the learned standard one day earlier than the high-exposed group. Furthermore, the ratio of qualified mice in the high-exposed group was always the lowest among the groups, indicating that high BPA treatment significantly altered the spatial memory performance of mice. Different BPA treatments exerted different effects on the neuron numbers of different regions in the hippocampus. In the CA1 region, the high-exposed group had a significant decrease in neuron numbers. A non-monotonic relationship was observed between the exposure concentrations and neuron quantity in the CA3 region. The hippocampal slices in the control and medium-exposed groups generated long-term potentiation after induction by theta burst stimulation, but the low-exposed group did not. A significant difference was observed between the control and low-exposed groups. In conclusion, chronic exposure to a low level of BPA had adverse effects on brain cells and altered the learning and memory ability of adolescent mice.

Evaluation of Stage-Dependent Genotoxic Effect of Roundup® (Glyphosate) on Caiman latirostris Embryos.

The agricultural expansion over the past decades, along with the associated increase in the use of pesticides, represents a high risk for many wild species. Caiman latirostris is a South American caiman with many features that make it highly vulnerable to pesticide exposure. Considering previous finding on the genotoxicity of the glyphosate-based formulation Roundup® in this species, the aim of this study was to evaluate the possible stage-dependent effect of this compound on C. latirostris embryos through the Comet assay (CA), micronuclei (MN), and nuclear abnormalities (NA) tests. Caiman eggs were exposed to three effective concentrations of Roundup® (750, 1250, 1750 µg/egg) in three different stages of the incubation period (total duration 70 ± 3 days at 31 ± 2 °C) of approximately 23 days each. A statistically significant difference in DNA damage determined by the CA was found between groups exposed to different concentrations of RU (p < 0.05) and the negative control, but no difference was observed among the three stages of exposure within any treatment (p > 0.05). There was no differences in the MN or NA frequencies between the different groups and the negative control (p > 0.05), nor among the different stages within each treatment. The results obtained in this study indicate that RU produce DNA damage on C. latirostris embryos independently of the developmental stage where the exposure occurs, implying an important risk for the species during all its period of development, when pesticide application is at maximum rate.

DNA Damage Response Plays Critical Role In Liver Regeneration After Acetaminophen Overdose

Acetaminophen (APAP) overdose is a leading cause of Acute Liver Failure (ALF). Previous studies have shown that liver regeneration followed by APAP overdose plays a critical role in survival. Here we show that significant DNA double strand break leading to inhibited DNA repair results in prolonged activation of cell cycle checkpoint delaying liver regeneration. We used a novel incremental dose model developed in our laboratory using a regenerating (300 mg/kg, APAP300) and a non‐regenerating (600 mg/kg, APAP600) dose of APAP to identify pathways involved in regeneration after APAP overdose. Marker of liver injury, regeneration and microarray‐based global gene expression changes were studied in male C57BL6 mice over time course of 0 to 72 hr following treatment with either APAP300 or APAP600. The ingenuity pathway analysis of microarray data revealed significant differences in DNA damage, replication and checkpoint related pathways between both doses of APAP. Western blot and immunofluorescence staining of pH2AX Ser139, a hallmark of DNA double strand break, showed prolonged phosphorylation of histone H2AX in mice treated with APAP600 than APAP300. DNA repair proteins involved in Non Homologous End Joining (NHEJ) pathway showed a rapid induction in APAP300 but were significantly suppressed in APAP600, indicating delay or lack of DNA repair. Further, extensive stabilization and activation of p53, the DNA damage Response (DDR) effector protein, was observed in APAP600 as compared to APAP300. p53 stabilization was accompanied by significantly higher and prolonged activation of several p53 target genes such as GADD45α,PAI1, BAX, p21 in APAP600 treated mice as compared to APAP300 treated mice. Furthermore, studies in p53KO mice showed significantly higher injury than WT mice after APAP300 treatment at initial time points. Interestingly, despite the higher injury, p53KO mice recovered similarly as the WT mice due to faster cell cycle resulting in much higher liver regeneration. These data illustrate that lack of prompt DSB repair response after APAP overdose leads to p53‐mediated prolonged growth arrest and replicative senescence. These results suggest that improving DNA repair process to rapidly decrease cell cycle checkpoint alert resulting in faster initiation of liver regeneration following APAP overdose may have therapeutic benefit.Support or Funding InformationThese studies were supported by NIH‐COBRE (P20 RR021940‐03), NIEHS Toxicology Training Grant (T32ES007079‐34) and NIDDK R0198414

Cryopreservation of ovaries from neonatal marmoset monkeys

The ovary of neonatal nonhuman primates contains the highest number of immature oocytes, but its cryopreservation has not yet been sufficiently investigated in all life stages. In the current study, we investigated cryodamage after vitrification/warming of neonatal ovaries from a nonhuman primate, the common marmoset (Callithrix jacchus). A Cryotop was used for cryopreservation of whole ovaries. The morphology of the vitrified/warmed ovaries was found to be equivalent to that of fresh ovaries. No significant difference in the number of oocytes retaining normal morphology per unit area in histological sections was found between the two groups. In an analysis of dispersed cells from the ovaries, however, the cell viability of the vitrified/warmed group tended to be decreased. The results of a comet assay showed no significant differences in DNA damage. These results show that cryopreservation of neonatal marmoset ovaries using vitrification may be useful as a storage system for whole ovaries.

Cytotoxicity evaluation of biodegradable Zn-3Mg alloy toward normal human osteoblast cells.

The recent proposal of using Zn-based alloys for biodegradable implants was not supported with sufficient toxicity data. This work, for the first time, presents a thorough cytotoxicity evaluation of Zn-3Mg alloy for biodegradable bone implants. Normal human osteoblast cells were exposed to the alloy's extract and three main cell-material interaction parameters: cell health, functionality and inflammatory response, were evaluated. Results showed that at the concentration of 0.75mg/ml alloy extract, cell viability was reduced by ~50% through an induction of apoptosis at day 1; however, cells were able to recover at days 3 and 7. Cytoskeletal changes were observed but without any significant DNA damage. The downregulation of alkaline phosphatase protein levels did not significantly affect the mineralization process of the cells. Significant differences of cyclooxygenase-2 and prostaglandin E2 inflammatory biomarkers were noticed, but not interleukin 1-beta, indicating that the cells underwent a healing process after exposure to the alloy. Detailed analysis on the cell-material interaction is further discussed in this paper.

Sevoflurane Induces DNA Damage Whereas Isoflurane Leads to Higher Antioxidative Status in Anesthetized Rats.

Taking into account that there are controversial antioxidative effects of inhalational anesthetics isoflurane and sevoflurane and absence of comparison of genotoxicity of both anesthetics in animal model, the aim of this study was to compare DNA damage and antioxidant status in Wistar rats exposed to a single time to isoflurane or sevoflurane. The alkaline single-cell gel electrophoresis assay (comet assay) was performed in order to evaluate DNA damage in whole blood cells of control animals (unexposed; n = 6) and those exposed to 2% isoflurane (n = 6) or 4% sevoflurane (n = 6) for 120 min. Plasma antioxidant status was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. There was no statistically significant difference between isoflurane and sevoflurane groups regarding hemodynamic and temperature variables (P > 0.05). Sevoflurane significantly increased DNA damage compared to unexposed animals (P = 0.02). In addition, Wistar rats anesthetized with isoflurane showed higher antioxidative status (MTT) than control group (P = 0.019). There were no significant differences in DNA damage or antioxidant status between isoflurane and sevoflurane groups (P > 0.05). In conclusion, our findings suggest that, in contrast to sevoflurane exposure, isoflurane increases systemic antioxidative status, protecting cells from DNA damage in rats.

Influence of different iodinated contrast media on the induction of DNA double‐strand breaks after in vitro X‐ray irradiation

The objective of this work was to examine differences in DNA double-strand break induction in peripheral blood lymphocytes after in vitro X-ray irradiation between iodinated contrast agents. Four different iodinated X-ray contrast agents--three of them with two different iodine concentrations--and mannitol (negative control; concentration of 150 mg mannitol per ml blood) were pipetted into blood samples so that there was a concentration of 0, 7.5 or 15 mg of iodine per ml blood in the samples. Negative controls without contrast medium (0 mg of iodine per ml blood) were also processed for every irradiation dose. The tubes were exposed to 0, 20 or 500 mGy in vitro X-ray irradiation. After that, the lymphocytes were separated by using density-gradient centrifugation. Fluorescence microscopy was applied to determine the average number of γH2AX-foci per lymphocyte in the presence or absence of different contrast media or mannitol. Differences in the number of γH2AX-foci were statistically analysed by one-way ANOVA and post-hoc Tukey's honestly significant difference test. Iodinated contrast agents led to a statistically significant increase in DNA double-strand breaks after in vitro irradiation. This effect increased statistically significant with rising radiation dose and appeared independent of the contrast agent used (iopromid, iodixanol, iomeprol, iopamidol). A statistically significant difference in DNA damage between the different tested contrast agents was not found. Therefore, the increase in DNA double-strand breaks depends solely on the amount of iodine applied. For evaluation of clinical consequences, our findings could be tested in further animal studies.

Effect of short-term storage on quality parameters, DNA integrity, and oxidative stress in Russian (Acipenser gueldenstaedtii) and Siberian (Acipenser baerii) sturgeon sperm

The sperm of Russian sturgeon (A. gueldenstaedtii) and Siberian sturgeon (A. baerii) was used to evaluate the effects of short-term (liquid) storage on functional parameters (spermatozoa motility and velocity), DNA integrity and oxidative stress indices. Spermatozoa showed >50% motility during 6 days of storage with an average velocity of 133.12±15.4 to 87.9±11.23μm s−1 in both species. No motile spermatozoa were recorded after nine days of storage. Analysis of Russian sturgeon sperm showed no significant differences in DNA damage expressed as percent tail DNA and Olive Tail Moment for first three days of storage. In Siberian sturgeon significant differences in DNA damage were detected after two days of storage. The level of oxidative stress indices (TBARS, CP) and antioxidant activity (SOD) increased significantly with storage time in both species. Results of this study can be utilized for successful reproduction management and cryopreservation protocols of these endangered species.

DNA damage of blood lymphocytes and neutrophils in cattle with lymphosarcoma

&amp;nbsp; The objective of the present study was to analyze the apoptotic process in peripheral blood mononuclear cells (PBMC) and polymorphonuclear neutrophil leukocytes (PMN) in cows clinically affected with lymphosarcoma. Thirteen cows were studied. Of them, eight, that were referred because of inappetance, loss of body condition, diarrhoea, constipation, protrusion of third eyelid, and exophthalmia, were seropositive for bovine leukemia virus (BLV) based on a serum enzyme-linked immunosorbent assay. Other animals were apparently healthy and were used as controls. DNA damage of PBMC and PMN was assessed using the Comet assay. The results obtained showed a statistically significant difference in DNA damage between the PBMC and PMN isolated from cows infected with BLV compared to PBMC and PMN isolated from healthy cows. This is the first article to document decreased apoptosis of blood PBMC and PMN in cattle in response to BLV infection using the Comet assay.