ABSTRACT
PURPOSE: The objective of the study was to estimate the DNA damage in blood leukocytes at long terms after irradiation of mice with carbon ions (450 MeV/nucleon) both before and in the Bragg peak. MATERIALS AND METHODS: White outbred SHK male mice were exposed to whole-body irradiation with carbon ions at doses of 0.1-2 Gy in the spread-out Bragg peak and at a dose of 6 Gy before and in the Bragg peak. At different times after irradiation (1-75 days), whole blood was collected from the tail of each mouse and analyzed by the comet assay. Mice X-irradiated in the same dose range served as a positive control. The level of the expression of mRNA of CDKN1A, APEX1, BBC3, TXN2, and ß-ACT genes in bone marrow cells was determined in animals irradiated with carbon ions at doses of 0.1-2 Gy using the real-time PCR. RESULTS: It was found that, 24 h after 12C-irradiation, a dose-dependent (0.1-2 Gy) increase in the DNA damage of leukocytes occurred, which was accompanied by a decrease in their concentration and an increase in the expression of the CDKN1A and BBC3 genes in bone marrow cells. The expression of the APEX1 and TXN2 genes did not change. In mice 12C-irradiated at a dose of 6 Gy before and in the Bragg peak, the level of DNA damage changed as follows: by day 3, it increased; by day 23 it returned to the control level; by day 30, it increased again; and by day 75, it fell to the control level on irradiation before the Bragg peak and was significantly higher (p < .05) than in the control after irradiation in the Bragg peak. CONCLUSIONS: The dynamics of changes in the level of DNA damage in leucocytes of 12C-irradiated mice within 30 days is similar to that in mice exposed to sublethal doses of X-radiation. The retention of the high level of DNA damage by day 75 after 12C-irradiation in the Bragg peak indicates a significant injury of cells from different cell pools of the blood system. The high level of DNA damage may be related not only to complex DNA injuries but also to chronic oxidative stress.
Subject(s)
Carbon/pharmacology , DNA Damage , Leukocytes/metabolism , Leukocytes/radiation effects , Animals , Dose-Response Relationship, Radiation , Male , Mice , Time FactorsABSTRACT
The comet assay was used to study the DNA damage that was induced by dimethoate in the hemocyte cells of adult Chorthippus biguttulus grasshoppers (Insecta: Orthoptera) that originated from two sites with varying levels of pollution. The primary focus of the study was to examine whether continuous exposure to environmental stress can modify the effect of pesticides on genome stability. After three days of acclimation to laboratory conditions, the level of DNA damage in the hemocytes of Bow-winged grasshoppers was within a similar range in the insects from both areas. However, the level of DNA damage following dimethoate treatment was significantly higher in the insects from the reference area (Pogoria) than in the individuals from the heavily polluted location (Szopienice). Four hours after pesticide treatment, the Tail DNA (TDNA) in the hemocytes of the male and female specimens from Pogoria was as high as 75% and 50% respectively, whereas the values in males and females from Szopienice only reached 30% and 20%, respectively. A rapid decrease in DNA damage was observed in both populations 24 h after the pesticide application. The habitat of an insect (site), the administration of the dimethoate (treatment), and the period following the application of the pesticide (time), all significantly influenced the levels of DNA damage. No interactions related to TDNA were observed between the variables 'sex' and 'treatment'. Similarly, the variable 'sex', when analyzed alongside 'treatment' and 'site' (the area from which the insects were collected), or 'treatment' and 'time' had no influence on TL. Exposure to dimethoate undoubtedly contributed to the formation of DNA damage in the hemocytes of adult C. biguttulus. However, the level of damage was clearly dependent on the place where the insects were captured.
Subject(s)
DNA Damage/drug effects , Dimethoate/toxicity , Ecosystem , Grasshoppers/drug effects , Grasshoppers/genetics , Hemocytes/drug effects , Insecticides/toxicity , Animals , Comet Assay , Environmental Pollutants/toxicityABSTRACT
Acrylamide (ACR) and glycidyl methacrylate (GMA) are structurally related compounds used for making polymers with various properties. Both chemicals can be present in food either as a byproduct of processing or a constituent of packaging. We performed a comprehensive evaluation of ACR and GMA genotoxicity in Fisher 344 rats using repeated gavage administrations. Clastogenicity was measured by scoring micronucleated (MN) erythrocytes from peripheral blood, DNA damage in liver, bone marrow and kidneys was measured using the Comet assay, and gene mutation was measured using the red blood cell (RBC) and reticulocyte Pig-a assay. A limited histopathology evaluation was performed in order to determine levels of cytotoxicity. Doses of up to 20 mg/kg/day of ACR and up to 250 mg/kg/day of GMA were used. ACR treatment resulted in DNA damage in the liver, but not in the bone marrow. While ACR was not a clastogen, it was a weak (equivocal) mutagen in the cells of bone marrow. GMA caused DNA damage in the cells of bone marrow, liver and kidney, and induced MN reticulocytes and Pig-a mutant RBCs in a dose-dependent manner. Collectively, our data suggest that both compounds are in vivo genotoxins, but the genotoxicity of ACR is tissue specific.
Subject(s)
Acrylamide/toxicity , Comet Assay , Epoxy Compounds/toxicity , Methacrylates/toxicity , Acrylamide/administration & dosage , Animals , Dose-Response Relationship, Drug , Epoxy Compounds/administration & dosage , Male , Methacrylates/administration & dosage , RatsABSTRACT
The blood plasma of healthy people contains cell-fee (circulating) DNA (cfDNA). Apoptotic cells are the main source of the cfDNA. The cfDNA concentration increases in case of the organism's cell death rate increase, for example in case of exposure to high-dose ionizing radiation (IR). The objects of the present research are the blood plasma and blood lymphocytes of people, who contacted occupationally with the sources of external gamma/neutron radiation or internal ß-radiation of tritium N = 176). As the controls (references), blood samples of people, who had never been occupationally subjected to the IR sources, were used (N = 109). With respect to the plasma samples of each donor there were defined: the cfDNA concentration (the cfDNA index), DNase1 activity (the DNase1 index) and titre of antibodies to DNA (the Ab DNA index). The general DNA damage in the cells was defined (using the Comet assay, the tail moment (TM) index). A chronic effect of the low-dose ionizing radiation on a human being is accompanied by the enhancement of the DNA damage in lymphocytes along with a considerable cfDNA content reduction, while the DNase1 content and concentration of antibodies to DNA (Ab DNA) increase. All the aforementioned changes were also observed in people, who had not worked with the IR sources for more than a year. The ratio cfDNA/(DNase1×Ab DNA × TM) is proposed to be used as a marker of the chronic exposure of a person to the external low-dose IR. It was formulated the assumption that the joint analysis of the cfDNA, DNase1, Ab DNA and TM values may provide the information about the human organism's cell resistivity to chronic exposure to the low-dose IR and about the development of the adaptive response in the organism that is aimed, firstly, at the effective cfDNA elimination from the blood circulation, and, secondly - at survival of the cells, including the cells with the damaged DNA.
Subject(s)
DNA Damage/radiation effects , DNA/radiation effects , Lymphocytes/radiation effects , Occupational Exposure , Adult , Aged , Apoptosis/radiation effects , Beta Particles , Comet Assay , DNA/blood , Deoxyribonuclease I/metabolism , Dose-Response Relationship, Radiation , Female , Gamma Rays , Humans , Male , Middle Aged , Neutrons , Nuclear Power Plants , Russia , TritiumABSTRACT
Introducción: los trastornos del espectro autista se consideran una familia de alteraciones del neurodesarrollo, caracterizada por dificultades en la comunicación y la interacción social, así como la existencia de un comportamiento estereotipado y repetitivo. Aunque existen varias hipótesis que involucran a factores genéticos y ambientales en su etiopatogenia, la verdadera contribución de estos aún se desconoce. En este estudio se explora la relación entre los niveles séricos de plomo, el daño del ADN y la severidad del autismo. Métodos: se estudiaron 15 niños con el diagnóstico de trastornos del espectro autista entre 4 y 11 años de edad y un grupo control del mismo rango de edad. El coeficiente de inteligencia fue evaluado mediante la prueba de Terman-Merrill y los niños fueron clasificados en dos grados de retardo mental (ligero y moderado/severo). Los niveles de plomo en sangre fueron medidos por espectrometría de masa, mientras que el daño del ADN fue determinado en linfocitos de sangre periférica con el empleo de un ensayo de electroforesis alcalina (ensayo del cometa). Resultados: no se mostró diferencia significativa en los niveles de plomo entre los grupos. El daño del ADN fue mayor en los pacientes autistas en relación con el grupo control, cuya diferencia fue significativa (p< 0,05), cuando comparamos los grupos teniendo en cuenta la severidad del retardo mental. Los pacientes con trastorno moderado/severo mostraron un daño del ADN significativamente superior a los que presentaron trastornos ligeros y al grupo control. Conclusiones: los resultados confirman la presencia de daño del ADN en pacientes con trastornos del espectro autista, lo cual sugiere que este pudiera ser un factor que se relaciona con la severidad del retardo mental en estos enfermos(AU)
Introduction:autistic spectrum disorders are considered to be a family of neurodevelopmental alterations characterized by difficulty to communicate and interact socially, as well as stereotyped, repetitive behavior. Though several hypotheses involve genetic and environmental factors in the etiopathogeny of this condition, their actual participation is still unknown. The present study explores the relationship between serum lead levels, DNA damage and the severity of autism. Methods: a study was conducted with 15 children 4-11 years old diagnosed with autistic spectrum disorders and a control group from the same age range. The intelligence quotient was measured by the Terman-Merrill test, and children were classified into two degrees of mental retardation (mild and moderate/severe). Blood lead levels were measured by mass spectrometry, whereas DNA damage was determined in peripheral blood lymphocytes using the alkaline electrophoresis assay (the comet assay). Results: this study did not show any significant difference in lead levels between the groups. DNA damage was greater in autistic patients than in the control group, and the difference was significant (p<0.05) when mental retardation severity was considered. Patients with a moderate/severe disorder showed significantly greater DNA damage than those with mild disorders and the control group. Conclusions: results confirm the presence of DNA damage in patients with autistic spectrum disorders, suggesting that this factor could be related to mental retardation severity(AU)
Subject(s)
Humans , Male , Female , Child , Autistic Disorder/etiology , Lead/blood , DNA Damage/genetics , Comet Assay/methods , Epidemiology, Descriptive , Observational Studies as TopicABSTRACT
Introducción: los trastornos del espectro autista se consideran una familia de alteraciones del neurodesarrollo, caracterizada por dificultades en la comunicación y la interacción social, así como la existencia de un comportamiento estereotipado y repetitivo. Aunque existen varias hipótesis que involucran a factores genéticos y ambientales en su etiopatogenia, la verdadera contribución de estos aún se desconoce. En este estudio se explora la relación entre los niveles séricos de plomo, el daño del ADN y la severidad del autismo. Métodos: se estudiaron 15 niños con el diagnóstico de trastornos del espectro autista entre 4 y 11 años de edad y un grupo control del mismo rango de edad. El coeficiente de inteligencia fue evaluado mediante la prueba de Terman-Merrill y los niños fueron clasificados en dos grados de retardo mental (ligero y moderado/severo). Los niveles de plomo en sangre fueron medidos por espectrometría de masa, mientras que el daño del ADN fue determinado en linfocitos de sangre periférica con el empleo de un ensayo de electroforesis alcalina (ensayo del cometa). Resultados: no se mostró diferencia significativa en los niveles de plomo entre los grupos. El daño del ADN fue mayor en los pacientes autistas en relación con el grupo control, cuya diferencia fue significativa (p< 0,05), cuando comparamos los grupos teniendo en cuenta la severidad del retardo mental. Los pacientes con trastorno moderado/severo mostraron un daño del ADN significativamente superior a los que presentaron trastornos ligeros y al grupo control. Conclusiones: los resultados confirman la presencia de daño del ADN en pacientes con trastornos del espectro autista, lo cual sugiere que este pudiera ser un factor que se relaciona con la severidad del retardo mental en estos enfermos
Introduction:autistic spectrum disorders are considered to be a family of neurodevelopmental alterations characterized by difficulty to communicate and interact socially, as well as stereotyped, repetitive behavior. Though several hypotheses involve genetic and environmental factors in the etiopathogeny of this condition, their actual participation is still unknown. The present study explores the relationship between serum lead levels, DNA damage and the severity of autism. Methods: a study was conducted with 15 children 4-11 years old diagnosed with autistic spectrum disorders and a control group from the same age range. The intelligence quotient was measured by the Terman-Merrill test, and children were classified into two degrees of mental retardation (mild and moderate/severe). Blood lead levels were measured by mass spectrometry, whereas DNA damage was determined in peripheral blood lymphocytes using the alkaline electrophoresis assay (the comet assay). Results: this study did not show any significant difference in lead levels between the groups. DNA damage was greater in autistic patients than in the control group, and the difference was significant (p<0.05) when mental retardation severity was considered. Patients with a moderate/severe disorder showed significantly greater DNA damage than those with mild disorders and the control group. Conclusions: results confirm the presence of DNA damage in patients with autistic spectrum disorders, suggesting that this factor could be related to mental retardation severity
