Degree Of DNA Fragmentation Research Articles

Quantification of the thermal history of insects in foods using real-time PCR-based DNA fragmentation analysis

A major challenge faced by the food industry is the contamination of food by insects. Once an insect is found in a food product, it is important to determine how it entered the food. Given that the thermal history of insects provides a clue to unraveling this mystery, in this study, we have developed a novel real-time PCR-based DNA fragmentation analysis method to quantify the thermal history of insects found in foods.We selected two species of cockroaches (Periplaneta fuliginosa and Blattela germanica) as investigative targets because cockroach contamination often causes significant economic losses in the food industry. A set of real-time PCRs was designed for each species to amplify the species-specific regions of 18S ribosomal DNA at approximate 100 and 300 bp. The degree of DNA fragmentation was evaluated using the differences between the amplification curves for the 100- and 300-bp sequences. We observed that the degree of DNA fragmentation was quantifiable when the insect was heated to >100 °C. Therefore, we determined whether cockroaches contaminate retort foods during the manufacturing or household consumption stages. This novel analytical method is expected to improve food safety and product reliability by identifying the cause of insect contamination.

Expression of exosomal microRNAs miR-34a and miR-210 in male infertility: relationship with morphokinetic parameters and sperm DNA fragmentation

Introduction. Infertility affects tens of millions of men and women across the globe. In approximately half of cases, male factors are the cause of infertility. In recent decades, there has been a significant decline in the quality of male ejaculate, which is characterized by reduced sperm concentration and motility. The insufficient diagnostic and prognostic value of routine semen analysis results highlights the challenge of developing effective diagnostic tools and searching for reliable biomarkers of male infertility. One of the most promising approaches may be assessing sperm microRNA expression.Objective. To study the role of sperm exosomal microRNAs miR-34a and miR-210 in the development of male infertility.Materials & methods. The retrospective study included 150 men aged 25 – 49 years; of these, 96 patients were diagnosed with idiopathic infertility. The comparison group consisted of 54 fertile men. To assess the structure and motility of sperm, the results of a standard ejaculate study (WHO, 2021) and computer data analysis using MMC Sperm (MMCSoft, St. Petersburg, Russia) software were used. The degree of DNA fragmentation was assessed using the TUNEL method. To analyze the expression of miR-34a and miR-210, quantitative real-time PCR was performed using the miRCURY LNA SYBR Green PCR Kit («Qiagen» GmbH, Hilden, Germany) and the Rotor-Gene Q PCR product detection system («Qiagen» GmbH, Hilden, Germany).Results. The study of ejaculate using the Computer Assisted Sperm Analysis System (CASA) method revealed a statistically significant relationship between the level of DNA fragmentation of sperm and indicators of the speed of their movement: rectilinear (VSL) (r = -0.522726; p < 0.01), curvilinear (VCL) (r = -0.499096; p < 0.01), along the middle path (VAP) (r = -0.429533; p < 0.01), as well as with the amplitude of lateral head displacement (ALH) (r = -0.294779, p < 0.01), the linearity of their curvilinear path (LIN) (r = -0.385796; p < 0.01), the degree of straight-line movements (STR) (r = -0.268248; p < 0.05) and their progressive mobility (r = -0.411547; p < 0.01). A study of the level of microRNA expression in sperm exosomes revealed a statistically significant decrease in its miRNA-34a pool (p = 0.0116). According to the Chaddock scale, the strength of the correlation between miR-210 expression and the effectiveness of ART programs was moderate (0.437993). The inverse relationship between miR-34a expression and IVF and ICSI results was weak (0.135314).Conclusion. The analysis of exosomal microRNA-34a and microRNA-210, which are involved in the regulation of spermatogenesis, reveals a direct correlation between their variations and changes in the kinetic and morphological parameters of gametes. It also indicates a relationship with the state of DNA fragmentation. These findings suggest varying levels of gene expression among infertile patients, men with proven fertility, and those undergoing assisted reproductive technology (ART) treatments, both with successful and repeated unsuccessful outcomes.

The Influence of Tanning Chemical Agents on DNA Degradation: A Robust Procedure for the Analysis of Tanned Animal Hide-A Pilot Study.

Illegal wildlife trade is currently on the rise, and it is becoming one of the most lucrative crime sectors. The rarer the species, the higher the demand. Wildlife trade falls under international regulations, such as the CITES convention. Proving that this convention has been violated is a complex process and can be very difficult to do. DNA analysis methods remain (in many cases) the only way to determine whether a certain specimen originated from a protected animal species, a specific individual, or a species in which it is legal to trade. Tanned animal hides are a specific type of specimen. With this type of biological material, obtaining amplifiable DNA is often difficult. This pilot study aimed to map the effect of the chemicals used in the tanning process on the degradation of the DNA yielded from such samples. The DNA was quantified using two different approaches: qPCR and Qubit fluorometry. The degree of DNA fragmentation was assessed by determining the degradation index. The results indicate that reagents containing chromium have the greatest influence on DNA degradation. However, by using the presented protocol, enough amplifiable DNA can be obtained from hides treated with aluminum-based reagents.

Haplosporidium pinnae Parasite Detection in Seawater Samples.

In this study, we investigated the presence of the parasite Haplosporidium pinnae, which is a pathogen for the bivalve Pinna nobilis, in water samples from different environments. Fifteen mantle samples of P. nobilis infected by H. pinnae were used to characterize the ribosomal unit of this parasite. The obtained sequences were employed to develop a method for eDNA detection of H. pinnae. We collected 56 water samples (from aquaria, open sea and sanctuaries) for testing the methodology. In this work, we developed three different PCRs generating amplicons of different lengths to determine the level of degradation of the DNA, since the status of H. pinnae in water and, therefore, its infectious capacity are unknown. The results showed the ability of the method to detect H. pinnae in sea waters from different areas persistent in the environment but with different degrees of DNA fragmentation. This developed method offers a new tool for preventive analysis for monitoring areas and to better understand the life cycle and the spread of this parasite.

Protective effect of Lycium barbarum leaf extracts on atopic dermatitis: in vitro and in vivo studies.

Atopic dermatitis (AD) is a chronic disease with an increasing incidence globally; therefore, there is a growing demand for natural compounds effective in treating dermatitis. In this study, the protective effects of Lycium barbarum leaves with and without chlorophyll (LLE and LLE[Ch-]) on AD were investigated in animal models of AD and HaCaT cells. Further, we investigated whether LLE and LLE(Ch-) show any differences in physiological activity. AD was induced by 2,4-dinitrochlorobenzene (DNCB) for three weeks, while NC/Nga mice were fed LLE or LLE(Ch-) extracts for 7 weeks. Serum immunoglobulin E (IgE) and cytokine (tumor necrosis factor [TNF]-α, interleukin [IL]-6, and IL-4) concentrations and the degree of DNA fragmentation in lymphocytes were examined. A histopathological examination (haematoxylin & eosin staining and blue spots of toluidine) of the dorsal skin of mice was performed. To elucidate the mechanism of action, the expression of the thymus and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC) were measured in HaCaT cells. Serum IgE and cytokines (TNF-α and IL-6) levels as well as DNA fragmentation of lymphocytes were significantly decreased in AD-induced mice treated with LLE or LLE(Ch-) compared to those of the control group. The epidermal thickness of the dorsal skin and mast cell infiltration in the LLE group significantly reduced compared to that in the control group. The LLE extracts showed no cytotoxicity up to 1,000 µg/mL in HaCaT cells. LLE or LLE(Ch-)-treated group showed a reduction of TARC and MDC in TNF-α-and IFN-γ-stimulated HaCaT cells. These results suggest that LLE potentially improves inflammation by reducing the expression of chemokines that inhibit T helper 2 cell migration. LLE(Ch-) showed similar effects to LLE on blood levels of IgE, TNF-α and IL-6 and protein expression in HaCat cells, but the ultimate effect of skin improvement was not statistically significant. Therefore, both LLE and LLE(Ch-) can be used as functional materials to alleviate AD, but LLE(Ch-) appears to require more research to improve inflammation.

Gamma-Tocotrienol Synergistically Promotes the Anti-proliferative and Pro-apoptotic Effects of Etoposide on Breast Cancer Cell Lines.

Breast Cancer is one of the most commonly diagnosed cancers worldwide and a major cause of death among women. Although chemotherapeutic agents remain the keystones in cancer therapy, significant side effects have failed to provide a safe and tolerable treatment for cancer patients. Dietary antioxidant vitamins were extensively investigated over the past years and their relevance in cancer chemotherapy remains to be elucidated. In the current study, we aimed to investigate the anti-proliferative and apoptotic effects of combining γ-tocotrienol, a member of the vitamin E family, with the chemotherapeutic drug etoposide in MCF-7 and MDA-MB-231 breast cancer cell lines. The antiproliferative effect of etoposide combined with γ-tocotrienol was measured using MTS viability reagent. The pro-apoptotic effect was elucidated through Cell Death ELISA and dual Annexin V/PI staining followed by flow cytometric analysis. Our results showed that etoposide significantly decreased the cell growth of both cell lines, with MDA-MB-231 cells being more sensitive to etoposide treatment than MCF-7. Moreover, simultaneous treatment of both breast cancer cell lines with low doses of γ-tocotrienol and etoposide induced a synergistic antiproliferative effect (CI<1). Furthermore, the combination therapy significantly increased the percentage of total apoptotic cells in the MDA-MB-231 cell line and the degree of DNA fragmentation as compared to treatment with either compound alone. In conclusion, our results provide evidence for the profound anti-tumorigenic effect of combined etoposide and γ-tocotrienol in the breast cancer cell lines.

Establishment and Characterization of Carboplatin-Resistant Retinoblastoma Cell Lines.

Carboplatin-based chemotherapy is the primary treatment option for the management of retinoblastoma, an intraocular malignant tumor observed in children. The aim of the present study was to establish carboplatin-resistant retinoblastoma cell lines to facilitate future research into the treatment of chemoresistant retinoblastoma. In total, two retinoblastoma cell lines, Y79 and SNUOT-Rb1, were treated with increasing concentrations of carboplatin to develop the carboplatin-resistant retinoblastoma cell lines (termed Y79/CBP and SNUOT-Rb1/CBP, respectively). To verify resistance to carboplatin, the degree of DNA fragmentation and the expression level of cleaved caspase-3 were evaluated in the cells, following carboplatin treatment. In addition, the newly developed carboplatin-resistant retinoblastoma cells formed in vivo intraocular tumors more effectively than their parental cells, even after the intravitreal injection of carboplatin. Interestingly, the proportion of cells in the G0/G1 phase was higher in Y79/CBP and SNUOT-Rb1/CBP cells than in their respective parental cells. In line with these data, the expression levels of cyclin D1 and cyclin D3 were decreased, whereas p18 and p27 expression was increased in the carboplatin-resistant cells. In addition, the expression levels of genes associated with multidrug resistance were increased. Thus, these carboplatin-resistant cell lines may serve as a useful tool in the study of chemoresistance in retinoblastoma and for the development potential therapeutics.

Pharmacological prevention of renal ischemia-reperfusion injury in a rat model.

Renal ischemia-reperfusion injury (IRI) can lead to significant morbidity and mortality. It remains a leading cause of acute kidney injury and is therefore an important issue in trauma and renal transplant surgery. Various pharmaceutical agents have been used in an attempt to dampen the harmful effects of IRI but few have been shown to be useful clinically. Riluzole, Lidocaine and Lamotrigine have been demonstrated to show anti-ischaemic properties in other organs; however, their use has not been tested in the kidneys. We investigated Riluzole, Lidocaine and Lamotrigine for their preventive effects of renal IRI using a rat model. Winstar rats (n=48) were divided into four groups (n=12 per group)-three treatment groups and one control group. Riluzole, Lidocaine and Lamotrigine were given prior to renal ischemia only (IO) or IRI. The degree of ischemia was measured by glutathione levels and a TUNEL assay was used to measure DNA fragmentation. Riluzole, Lidocaine and Lamotrigine pre-treatment each resulted in statistically higher glutathione levels compared to controls (P=0.002; P=0.007 and P=0.005, respectively). Riluzole and Lidocaine were also effective at preventing depletion of glutathione following IO (P=0.007 and P=0.014 respectively), while Lamotrigine was ineffective in IO (P=0.71). The degree of DNA fragmentation seen on the TUNEL assay was markedly reduced in all three-drug groups in both IO and IRI. Riluzole, Lidocaine and Lamotrigine all have anti-ischaemic effects in the rat kidney and can have potential therapeutic implications.

Anti-Apoptotic Effect of Synthetic Leu-Enkephalin Dalargin on Rat Leukocytes in Cold Stress Model in Vivo

In this research, a protective effect of synthetic analogue of leu-enkephalin dalargin on peripheral blood leukocytes of cold stress-exposed homeotherms has been investigated. The impact of this peptide and in vivo cold stress on cell composition of leukoconcentrate, leukocyte viability and DNA fragmentation degree in rat leukocytes, has been studied by using confocal microscopy. A decreased relative count of lymphocytes and an increased neutrophil one were established as significantly less pronounced in the animals injected with dalargin before cooling, than in non-handled ones. The dalargin administration was also shown to enhance the viability of peripheral blood leukocytes in rats exposed to cold stress. Preliminary administration of dalargin to animals significantly reduced both the degree of DNA fragmentation and a relative count of leukocytes with fragmented DNA in peripheral blood. Simultaneous introduction of opioid receptor antagonist naloxone to animals eliminated a protective effect of opioid receptor agonist dalargin. Our findings demonstrated the opioid receptor-mediated antiapoptotic effect of dalargin on peripheral blood leukocytes under in vivo cold stress.

Detection of residual E. coli host cell DNA by 23S ribosomal RNA gene-targeted quantitative polymerase chain reactions

Among the many systems available for heterologous protein production gram-negative bacterium Escherichia coli (E. coli) has long been widely used because of its ability to grow rapidly with a high density on inexpensive substrates. The use of E. coli as the host system has many regulatory issues, one of which is the residual host cell DNA. Residual DNA carried by biological products may lead to carcinogenicity and immunomodulation risks. The World Health Organization (WHO) for the acceptable amounts of residual host cell DNA is less than 10 ng per dose. Therefore, it is important to keep an extremely low level of residual host DNA in the biological products derived from E. coli. In this study, we designed primer/probe sets targeting E. coli 23S ribosomal RNA gene to quantify the residual DNA of E. coli by quantitative polymerase chain reactions (qPCR). Result showed that this primer/probe has high species specificity. The limit of detection (LOD) in this method is 0.01 pg/μl and this allowed for detection of residual host DNA of much lower concentrations. We assessed accuracy by calculating the recovery (92.1∼140.1 %) of the spiked DNA in plasmids which were produced from E. coli. We also checked intra-assay precision (9.8∼15.1 %) and inter-assay precision (10.9∼18.3 %) by repeatedly measuring the four different concentration standards. In addition, the robustness assay was performed by generating standard curve using short length E. coli DNA. The result showed that appropriate degree of DNA fragmentation will not affect tests. These validation studies demonstrated that our method has excellent specificity, linearity, accuracy, precision and robustness.

Oxidative origin of sperm DNA fragmentation in the adult varicocele.

ABSTRACTPurpose:Sperm DNA fragmentation is a major cellular mechanism underlying varicocele-related male infertility. However, the type of DNA fragmentation - whether oxidative or of another nature - remains unknown. Thus, the aim of this study was to evaluate single- and double-stranded sperm DNA fragmentation, and oxidative-induced sperm DNA damage in men with varicocele.Materials and Methods:A cross-sectional study was performed, including 94 normozoospermic adults, of which 39 men without varicocele (controls) and 55 men with varicocele grades II or III, uni- or bilaterally. All men collected semen by masturbation. After semen analysis, the remaining volume was used for evaluation of three types of sperm DNA damage: (i) total DNA fragmentation, using an alkaline comet assay, (ii) double-stranded DNA fragmentation, using a neutral comet assay, and (iii) oxidative DNA damage, using an alkaline comet assay associated with the DNA glycosylase formamidopyrimidine enzyme. In each assay, percentage of sperm with any degree of DNA fragmentation, and with high DNA fragmentation were compared between the groups using an unpaired Student's t test or a Mann-Whitney test.Results:The varicocele group presented a higher rate of sperm with fragmented DNA (both any and high DNA fragmentation), considering single-stranded DNA fragmentation, double-stranded DNA fragmentation, or a combination of both, as well as oxidative- induced DNA fragmentation.Conclusions:Patients with varicocele have an increase in sperm DNA fragmentation levels, particularly in oxidative stress-induced sperm DNA damage.

Molecular analysis of H&E- and Papanicolau-stained samples-systematic review.

Molecular pathology allows the identification of causative agents in infectious diseases and detection of biomarkers important for prediction of disease susceptibility, diagnosis and personalized therapy. Accordingly, nucleic acid-based methods have gained a special role in clinical laboratories particularly to evaluate solid and hematological tumors. Extraction of nucleic acids is commonly performed in microdissected formalin-fixed paraffin-embedded (FFPE) or cytological samples that had been previously evaluated through the use of hematoxylin and eosin (H&E) or Papanicolau (Pap) stains, respectively. Although the effect of both stains on nucleic acids integrity has been explored by several authors, the results are not consistent and require further examination. Accordingly, the goal of this review was to assess the influence of H&E and Pap stains on DNA and RNA integrity and to address the mechanism by which each staining compromises molecular based-analysis. The analyzed studies demonstrate that H&E- and Pap-staining result in low DNA recovery and some degree of DNA fragmentation. Additionally, it is concluded that hemalum inhibits PCR by interfering with DNA extraction, preventing DNA polymerase attachment and possibly by rescuing divalent cations. Accordingly, proper sample purification and adjustment of PCR conditions are of key importance to achieve satisfactory results by PCR in H&E- and Pap-stained samples. Furthermore, although H&E results in RNA fragmentation, it is possible to perform expression analysis in H&E-stained frozen sections, using RNase-free conditions, low amounts of hematoxylin and a rapid protocol from sample collection to RNA analysis. It The effect of Pap-staining on RNA integrity remains to be determined.

Evaluation of possible molecular toxicity induced by occupational exposure to lead and concomitant effect of smoking.

One of the most toxic heavy metals in the environment nowadays is lead (Pb). Even though exposure to lead has been reduced in some developed countries, individuals working in certain occupations are still exposed to lead at dangerous levels. Occupational exposure is of great concern and is also the main cause of lead poisoning. Although experts in various fields have been investigating the toxic effects of lead and its compounds for many years now, the association between chronic lead exposure and geno-toxicity is still an interesting point of research. The study aims to evaluate the possible DNA damage and the oxidative stress status induced by occupational exposure to lead and the role of concomitant smoking. The study was conducted on 60 subjects divided into two groups: an exposed group (40 male workers exposed to lead in their workplaces). This group was further divided into two subgroups; 20 workers were cigarette smokers and the other 20 workers were non-smokers. The other control group consists of 20 healthy males, not exposed to lead and matched by age to the exposed group (10 were smokers and the rest were non-smokers). Venous blood samples were collected from each participant for the determination of the following: blood lead level (BLL), plasma malondialdehyde (MDA) levels, and DNA damage using agarose gel electrophoresis. The exposed workers had significantly higher levels of lead and MDA, as well as a high frequency of DNA fragmentation. Smoking workers showed a greater frequency of DNA fragmentation than non-smokers. A significant relation was revealed between the BLL, as well as the MDA level, and the degree of DNA fragmentation among the lead-exposed workers. The study has shown additional evidence proving the association between Pb exposure and oxidative stress. The results further reinforced the role of cigarette smoking in augmenting such oxidative damage in the Pb-exposed population. However, further studies are recommended to evaluate the effect of cigarette smoking on Pb-exposed workers.

The risk of sperm demage in men with the combined effect of endocrine disruptors

Background: The most frequent ultrastructural change in sperm cells is nuclear DNA fragmentation. Many authors believe that DNA damage to sperm cells can serve as a diagnostic marker of a negative paternal effect in the pre-implantation period of human development. A number of studies have shown a direct correlation between the high percentage of sperm DNA damage and the frequency of spontaneous abortions. On the other hand, it is known that the damaging effect of endocrine disruptors, for example, triclosan and bisphenol A, is based on their ability to induce oxidative stress, which is considered as one of the factors in cell DNA damage.&#x0D; Aims: to assess the risk of sperm DNA fragmentation in men with the combined effect of bisphenol A, triclosan and 4-nonylphenol in seminal fluid.&#x0D; Materials and methods: 84 samples of seminal fluid of men with normo-and patozoospermia were studied. The concentration of bisphenol A, triclosan and 4-nonylphenol in gas was determined by gas chromatography with mass spectrometry (GC-MS). The comparison groups were divided according to the degree of DNA fragmentation of spermatozoa into two groups: the 1st group of patients with DNA fragmentation of spermatozoa 15% (n=18) and the 2nd group 15% (n=29). The spermiological study was carried out according to the WHO recommendations (2010) taking into account the assessment of the number of spermatozoa, their motility and morphology, as well as the degree of fragmentation of the sperm DNA.&#x0D; Results: Bisphenol A was found in 100% of the ejaculate samples with a median concentration of 0.150 ng/ml. Triclosan and 4-nonylphenol were detected in 84.3 and 98.1% of ejaculate samples with a median concentration of 0.11 and 0.16 ng/ml respectively. Comparison groups were statistically significantly distinguished by the concentration of bisphenol A and triclosan p=0.014; p0.001 respectively. Triclosan with an increase in concentration in seminal fluid by 0.1 ng/ml increased the chance of development of the degree of DNA fragmentation 15% by 2.9 times. The odds ratio of bisphenol A and 4-nonylphenol to DNA damage was not statistically significant. The prognostic model of the joint effect of endocrine disruptors on DNA damage, constructed using multiple logistic regression analysis, was also found to be statistically significant only with respect to the effect of triclosan.&#x0D; Conclusions: The risk of damage to sperm DNA in men is primarily associated with the effect of triclosan in seminal fluid. At the same time, it is necessary to assume the absence of a synergistic effect of bisphenol A, triclosan and 4-nonylphenol on the DNA damage of spermatozoa in men.

Arabinoxylan rice bran (MGN-3/Biobran) enhances radiotherapy in animals bearing Ehrlich ascites carcinoma†.

ABSTRACTThis study examines the ability of arabinoxylan rice bran (MGN-3/Biobran) to enhance the anti-cancer effects of fractionated X-ray irradiation of Ehrlich solid tumor-bearing mice. Swiss albino mice bearing tumors were exposed to the following: (i) Biobran treatment (40 mg/kg/day, intraperitoneal injections) beginning on day 11 post-tumor cell inoculation until day 30; (ii) ionizing radiation (Rad) 2 Gy at three consecutive doses on days 12, 14 and 16; or (iii) Biobran + Rad. Final tumor weight was suppressed by 46% for Biobran, 31% for Rad and 57% for the combined treatment (Biobran + Rad) relative to control untreated mice. Biobran and Rad also arrested the hypodiploid cells in the sub-G1-phase, signifying apoptosis by +102% and +85%, respectively, while the combined treatment induced apoptosis by +123%, with similar results in the degree of DNA fragmentation. Furthermore, Biobran + Rad upregulated the relative gene expression and protein level of p53 and Bax in tumor cells, down-regulated Bcl-2 expression, and increased the Bax/Bcl-2 ratio and caspase-3 activity, with the combined treatment greater than for either treatment alone. Additionally, the combined treatment modulated the decrease in body weight, the increase in liver and spleen weight, and the elevation of liver enzymes aspartate aminotransferase, alanine aminotransferase and gamma-glutamyl transferase to be within normal values. We conclude that Biobran enhances radiation therapy-induced tumor regression by potentiating apoptosis and minimizing toxicities related to radiation therapy, suggesting that Biobran may be useful in human cancer patients undergoing radiotherapy and warranting clinical trials.

Toxic Effects of Low-Level Long-Term Inhalation Exposures of Rats to Nickel Oxide Nanoparticles.

Rats were exposed to nickel oxide nanoparticles (NiO-NP) inhalation at 0.23 ± 0.01 mg/m3 for 4 h a day 5 times a week for up to 10 months. The rat organism responded to this impact with changes in cytological and some biochemical characteristics of the bronchoalveolar lavage fluid along with a paradoxically little pronounced pulmonary pathology associated with a rather low chronic retention of nanoparticles in the lungs. There were various manifestations of systemic toxicity, including damage to the liver and kidneys; a likely allergic syndrome as indicated by some cytological signs; transient stimulation of erythropoiesis; and penetration of nickel into the brain from the nasal mucous membrane along the olfactory pathway. Against a picture of mild to moderate chronic toxicity of nickel, its in vivo genotoxic effect assessed by the degree of DNA fragmentation in nucleated blood cells (the RAPD test) was pronounced, tending to increasing with the length of the exposure period. When rats were given orally, in parallel with the toxic exposure, a set of innocuous substances with differing mechanisms of expected bioprotective action, the genotoxic effect of NiO-NPs was found to be substantially attenuated.

Use of statistical analysis to validate ecogenotoxicology findings arising from various comet assay components.

Cirrhinus mrigala, Labeo rohita, and Catla catla are economically important fish for human consumption in Pakistan, but industrial and sewage pollution has drastically reduced their population in the River Chenab. Statistics are an important tool to analyze and interpret comet assay results. The specific aims of the study were to determine the DNA damage in Cirrhinus mrigala, Labeo rohita, and Catla catla due to chemical pollution and to assess the validity of statistical analyses to determine the viability of the comet assay for a possible use with these freshwater fish species as a good indicator of pollution load and habitat degradation. Comet assay results indicated a significant (P < 0.05) degree of DNA fragmentation in Cirrhinus mrigala followed by Labeo rohita and Catla catla in respect to comet head diameter, comet tail length, and % DNA damage. Regression analysis and correlation matrices conducted among the parameters of the comet assay affirmed the precision and the legitimacy of the results. The present study, therefore, strongly recommends that genotoxicological studies conduct appropriate analysis of the various components of comet assays to offer better interpretation of the assay data.

165 Effect of Dimethyl Sulfoxide Supplementation During In Vitro Maturation on the Genetic Expression Pattern of Bovine Blastocyst

Supplementation of bovine oocytes with 0.5% (v/v) dimethylsulfoxide (DMSO) during in vitro maturation (IVM) results in increased blastocysts rates (Ynsaurralde et al. 2016 Reprod. Fertil. Dev. 29, 201-202). Recently, an important role of DMSO in stem cell differentiation has been observed, attributed to modulation of gene expression. However, the effect of DMSO suplementation during in vitro maturation on gene expression profiles and embryo quality have not been evaluated so far. Thus, we examinated the effect of DMSO during IVM on the expression of some key genes (Sox2, Oct4, and Cdx2) and on the degree of DNA fragmentation at the blastocyst stage. To this aim, cumulus–oocyte complexes collected from slaughterhouse ovaries were matured in TCM-199 containing 10% fetal bovine serum, 10 µg mL−1 FSH, 0.3 mM sodium pyruvate, 100 mM cysteamine, and 2% antibiotic-antimycotic for 24 h, at 6.5% CO2 in humidified air and 38.5°C. Maturation media was supplemented with 0, 0.5, or 0.75% (v/v) DMSO. In vitro fertilization (IVF) was performed with 16 × 106 spermatozoa per mL for 5 h. Afterwards, presumptive zygotes were cultured in SOF for 7 days at 38.5°C and 5% O2. Three pools of 5 blastocysts were analysed for each treatment. Gene expression analysis was performed by real-time qPCR and DNA fragmentation of blastocysts was measured by TUNEL assay (n = 8, 7, and 14 blastocysts analysed for 0, 0.5, and 0.75% v/v DMSO, respectively). The results were statistically analysed using ANOVA with a completely randomised model by InfoStat software Version 1.1 (https://www.infostat.com.ar/). The pluripotency marker genes Sox2 and Oct4 were up-regulated in blastocysts only when the oocytes were matured in 0.75% DMSO, whereas the trophoblastic marker Cdx2 showed no differences among treatments. No differences were detected in the number of TUNEL-positive cells among treatments: 10/65 (15%) in 0%, 19/110 (18%) in 0.5%, and 18/98 (20%) in 0.75% (v/v) DMSO. In conclusion, supplementation with 0.5% (v/v) DMSO, as previously published, increases the production of blastocysts without disrupting the expression pattern of the evaluated genes.

The “PHOENIX” Space Experiment: Study of Space Radiation Impact on Cells Genetic Apparatus on Board the International Space Station

The preliminary results of the 1st session of Russian “PHOENIX” long-term space experiment are presented. The survival of dried human lymphocytes and mouse bone marrow cells in 199 days space flight is studied. The degree of DNA fragmentation is analysed for samples flown in different ISS compartments. It is shown that biological data correlates with the results of space radiation dose measurements.

Dna damage in lymphocytes in chronic viral hepatitis B, C

Objective: determine grade of DNA damage in lymphocytes and the levels of 8-hydroxy-2-deoxyguanosine (8- OHdG) and 8-nitroguanine (8-NO2G), total antioxidant activity (TAA) in the blood serum of patients with chronic viral hepatitis C (HCV), B (HBV). Materials and methods. The study included 100 people with HCV, 50 with HBV and 43 volunteers. DNA damage was evaluated by comet assay. Level 8-NO2G and 8-OHdG were determined in serum samples using ELISA kits. TAA determined according to the standard ABTS method. All statisticalcalculations were performed and the graphs were plotted using STATISTICA 10.0 software. Results. There was a tendency to increase the level of DNA damage with progression of the liver fibrosis stage in HCV and HBV. Significant differences from the norm of 8-NO2G in the F1, F2, F3 groups with HCV and in the groups F2, F3, F4 (ρ <0,05) with HBV were found. In the groups with HCV and in F2 and F4 with HBV, the level of 8-OHdG is higher in comparison with the control group (ρ = 0,0001). Correlations are shown between the stage of hepatic fibrosis and the level of 8-NO2G and 8-OHdG, respectively (r = 0,786620 and r = 0,625844; ρ <0,05) with CVHC and CVHB (r = 0,573933 and r = 0, 478849; ρ <0,05). In the study of OAA, the tendency towards its depletion with the development of fibrotic changes was noted in patients, however, significant differences in comparison with the control were only at the stage of F3 and F4 fibrosis in CVHC, and F2, F4 (ρ <0,05) with CHBV. Conclusion. Revealed the genotoxic effect of hepatitis B and C on the DNA of lymphocytes. An increasing degree of DNA fragmentation with the progression of liver fibrosis. The correlation between fibrosis and biochemical markers of DNA damage and decrease shown decompensated TAA serum in advanced stages of liver fibrosis.