The effect of the spontaneous level of the chromosome aberration rate on its alterations after a single local irradiation

With X-ray examinations of the stomach and duodenum, changes in chromosomal aberration frequencies in peripheral blood lymphocytes were shown to depend on the spontaneous level of these aberrations in patients exposed to a single local irradiation by 25 R. The cytogenetic efficiency of radiation exposure was found to be local in patients with the lower frequency of spontaneous chromosomal aberrations. A genetic genesis of the revealed dependence is supposed. The effect of irradiation on the correlation between radiosensitivity and radioresistance of the cytogenetic process is regarded as a possible mechanism of the appearance of the observed dependence.     

Cytogenetic effect in peripheral blood lymphocytes of children living in villages in the Ovruch District, Zhitomir Region of the Ukraine contaminated by radionuclides]

For the purpose of genetic indication of low level of chronic radiation exposure the cytogenetic monitoring of some critical children groups living in two contaminated Ukrainian villages was carried out. In all the groups the mean frequency of aberrant cells and chromosome type aberrations (including dicentrics, centric rings, chromosome translocations as well as polyploid cells) significantly exceeded control level. During the repeated examination of children from Vistupovichi (in 13 months after the first one) the striking increase of cytogenetic effect was revealed. Dicentrics and rings were registered in 79% of persons with the individual rate 0.5-1.5 and mean group frequency 0.57 per 100 cells. The authors tried to evaluate the average cumulative doses of radiation for examined groups using G. Littlefield equation for dicentric outcome under the low dose rate Cs-137 source and taking into account the assumption about the reducing of 50% dicentrics per year. According to this rough calculation, the revealed cytogenetic effect can correspond to the mean total dose of 33 cSv for Vistupovichi children.     

Effect of separate radioactive and chemical pollutants on the yield of cytogenetic disruptions in the intercalary meristem in spring barley

Dependencies of the yield of cytogenetic disturbances within intercalary meristem cells of spring barley on the soil level of 137Cs (1.48-14.8 MBq/m2), Cd, Pb (2-50 and 30-300 mg per kilogram of the soil) and 2.4-D herbicide (1 or 2 kg/ha) had a non-linear character in the studied range. At low concentrations the yield of cytogenetic disturbances grew faster than at higher ones. Concentrations of lead in soil (at the level of maximum concentration limit) and doses of 2.4-D recommended for agricultural use resulted in the increase in the rate of aberrant cells. The observed rate of cytogenetic disturbances was comparable with the effect of the maximum studied level or the radioactive soil pollution. The heaviest damage to aberrant cells was found in the presence of 137Cs.     

Cytogenetic effect of the thiocarbamate herbicides butylate, molinate and vernolate in the mouse bone marrow micronucleus test

Three thiocarbamate herbicides, butylate (S-ethyl-diisobutylthiocarbamate), vernolate (S-propyl dipropylthiocarbamate) and molinate (S-ethyl-N,N-hexamethylenethiocarbamate) were assayed for cytogenetic effect in the mouse bone marrow micronucleus test. Butylate was inactive in bone marrow, vernolate caused a marginal increase in the incidence of micronucleated polychromatic erythrocytes only at a high toxic dose level. Molinate, the N,N-hexamethylene derivative was, however, strongly active in the bone marrow, causing a high frequency of micronucleated erythrocytes, even at subtoxic concentrations.     

Analysis of the cytogenetic effect in human lymphocytes induced by metabolically activated 1- and 2-methylnaphthalene

Chromosome analyses were carried out in human lymphocytes treated in vitro with 1- and 2-methylnaphthalene (1-MN, 2-MN) in the presence and absence of the mammalian metabolic activation system, S9 mix. Without S9 mix there was no indication of induction of any significant cytogenetic effect by either compound. With S9 mix a weak clastogenic effect was apparent at 4 mM 2-MN only and sister-chromatid exchange frequencies were significantly increased at each dose of 1- and 2-MN, yet always less than twice the control level. The present observations do not indicate that 1- and 2-MN must be classified as potential genotoxic substances.     

Modification of the cytogenetic effect of dioxidine in experimental alloxan diabetes in rats

A dependence was established between the cytogenetic effect of dioxydinum antibacterial drug and the disturbance of carbohydrate metabolism in rats with alloxan diabetes.     

Mutagenic effect of the cytostatic drug thaliblastine on rat bone marrow cells when administered alone and in combination with radiation

The cytogenetic analysis was performed in the bone marrow cells of Wistar rats treated with a therapeutic dose of thaliblastine (250 mg/kg) and exposed to gamma-rays (2 Gy). Thaliblastine alone induced chromosome aberrations and polyploid cells. The latter were the result of the stathmokinetic effect of the drug. In contrast to gamma-radiation of 2 Gy thaliblastine elicited a minor mutagenic effect. The cytogenetic effect of the combined treatment is greater than the sum of the two agents delivered separately, the maximum effect of radiation and thaliblastine being exhibited on the 8th and the 12th hour, respectively. The difference between the sum of aberrations after separate treatments and the yield of aberrations after the combined treatment is due to chromatid fragments.     

Cytogenetic effects of the addition of leukocytes and blood sera on human fibroblasts exposed to measles virus or to streptolysin-O

Infection with measles virus and also introduction of streptolysin-O induced a significant increase in the level of cells with cytogenetic disturbances in the culture of human fibroblasts (HF). A decrease to intact condition of the number of HF with aneuploid and polyploid sets of chromosomes was observed after the introduction of non-immune autologous T-lymphocytes into the cultures. Immune homologous T-lymphocytes, unlike non-immune autologous T-lymphocytes, eliminated cells with structural disturbances of the chromosomes from the culture, but did not influence the level of aneuploid and polyploid cells. The ability of immune T-lymphocytes to exert antimutagenic effect can obviously be explained by their cytolytic action on virus-infected cells. As for non-immune autologous T-lymphocytes, two ways are equally probable: T-lymphocytes eliminate HF with virus antigens on their surface, or T-lymphocytes determine and destroy fibroblasts with changed cell surface developing as a result of cytogenetic disturbances induced by infectious factors. Specificity of the cytolytic reaction of T-lymphocytes concerning cells with some types of cytogenetic disturbances has been demonstrated.     

Dependence of the cytogenetic effect on TEPA concentration in human lymphocyte culture]

The authors studied the cytogenetic action of TEPA (tris/2-methyl-1-azyridinyl) on the human lymphocyte culture. It was shown that the increase of the mutagen concentration from 0.125 to 16.0 microgram/ml the cytogenetic effect for the portion of the aberrant metaphases rose from 6.0 to 61.0%, and for the total number of ruptures - from 7.96 to 116.3. A method of finding the least effective concentration of the substance under study in comparison with control is suggested; for TEPA it constitutes 0.120 microgram/ml. The percentage of chromatide ruptures remained constant in using different TEPA concentration and constitutes 51.72%. Cell distribution of chromosome ruptures is satisfactorily described by geometrical distribution.     

Biological effect of 9 GeV protons and the radioprotective effect of ATP and AMP on epithelial cells of the mouse cornea

The cytogenetic and cytological effects induced in mouse cornea epithelium cells by 9 GeV protons and "standard" radiation have been studied. The RBE coefficients are different at different times of observation. ATP and AMP are shown to produce a protective effect on the frequency of formation of aberrant mitoses. DMF values for protons determined 24 and 72 h following irradiation are 1.8 +/- 0.2 and 1.7 +/- 0.2, respectively.     

The problem of immune antimutagenic control in cytogenetic damage induced by infectious processes

The injection of streptolysin-0 into the cultures of human fibroblasts (HF) reliably increased the number of cells with cytogenetic aberrations. The injection of non-immune autologous T-lymphocytes decreased the number of aneuploid HF to the intact state. Homologous lymphocytes, in contrast to autologous T-lymphocytes, had no effect on the level of cytogenetic damaged cells.     

The effect of the accident at the Chernobyl Atomic Electric Power Station in 1986 on the fish population of a cooling pond]

The cytogenetic analysis of Cyprinus carpio eyes, developing Blicca bjoerkna L. eggs, and eggs and larvae of Hypophtalmichthys molitrix Val. has demonstrated that the yield of cells with chromosome aberrations in the fish species under study is normal, while the level of variability of morphometric indices in offspring is considerably higher than that in parent fish.     

Evaluation of the mutagenic effect of the new fungicide trimorphamide

The new Czechoslovak fungicide trimorphamide was tested for its mutagenic activity. To evaluate the potential mutagenic effects on Drosophila, trimorphamide at 0.5, 1.0, 5.0, 10.0% was administered into the cultivation medium, and the sex-linked recessive lethal mutation detection test and the chromosome nondisjunction test were used. After administration of trimorphamide to mice at 60, 150 and 300 mg . kg-1 b.w. perorally, and 30, 70 and 150 mg . kg-1 b.w. intraperitoneally in single and repeated (5X) doses, a cytogenetic analysis of chromosomal aberrations in bone-marrow cells was performed. The cytogenetic analysis of human peripheral lymphocytes for chromosomal aberrations in vitro was performed 24 h after trimorphamide had been applied into the culture in concentrations 19.1 X 10(-3), 19.1 X 10(-4) and 19.1 X 10(-5) M. Under our testing conditions the trimorphamide concentrations used did not show any mutagenic effect upon Drosophila, compared with the controls. Also, under the conditions of the cytogenetic analysis, no significant increase in the frequency of chromosomal abnormalities in mouse bone marrow or in human peripheral lymphocyte was observed compared with the group of controls.     

Radiation-induced modification of human somatic cells’ chromosome sensitivity to the testing mutagenic exposure of bleomycin in vitro in lung cancer patients in delayed terms following chernobyl accident

The above-background level of cytogenetic effect has been studied using the modified G₂-bleomycin sensitivity assay, the value of which was a marker of hidden chromosome instability (HCI). The following three groups were examined: (1) Chernobyl disaster liquidators (CDLs) (occupational group I), (2) patients with lung cancer (LC) who denied voluntary contact with ionizing radiation (comparative group); and (3) patients with LC participating in the liquidation of the Chernobyl disaster (occupational group 2). Significant interindividual variations in the cytogenetic effects induced by bleomycin and the absence of a positive correlation with the background and above-background frequency of chromosome aberrations have been revealed for all the three groups. It was established that occupational group 2 experienced the highest level of above-background cytogenetic effect and therefore had the highest number of patients with HCI. The data allowed us to hypothesize the existence of an association between a radiation-induced increase in individual susceptibility to testing mutagenic exposure and the development of cancer pathologies in patients exposed to ionizing radiation. The results showed the feasibility of using the G₂-bleomycin sensitivity assay for the examination of irradiated contingents for the detection of HCI as an informative marker of predisposition to cancer.     

Dynamics of the cytogenetic effect in re-examined individuals who have participated in eliminating the emergency at the Chernobyl Atomic Power Plant in various periods after irradiation]

The repeat cytogenetic examination of 22 persons who were exposed to acute radiation while eliminating emergency at the Chernobyl Atomic Power Plant has revealed interindividual variability in the rate of elimination of radiation-induced chromosome mutations. The data obtained have confirmed complexity to reconstruct individual radiation doses by the results of cytogenetic analysis carried out 1-3 years after the ionizing radiation effect.     

A comparative study of the cytogenetic effect of a series of phosphoorganic pesticides]

A comparative study of the effect of 12 organophosphorus pesticides on mice was carried out. A statistically significant increase of the frequency of aberrant metaphases in bone-marrow cells of mice was induced by dipterex, metaphos, phosphamidon and imidan. No correlation between the toxicity and the mutagenic activity of the compounds studied was observed. The pesticides studied can be regarded as substances with a slight cytogenetic activity with respect to animals.     

Decrease in the cytogenetic effect of adriblastin and pharmorubicin with the experimental use of tularemia vaccine

Immunization of Wistar rats with tularemic vaccine has been studied for its influence on the cytogenetic effect of adryblastine and pharmorubicyn. It is shown that the number of aberrant metaphases considerably decreases in the myelocaryocytes of vaccinated rats. Antimutagenic effect is induced by the influence of tularemic vaccine on the metabolic activation processes of antibiotics and, possibly, by an increase of the activity of antioxidative enzymes in the rat organism.     

The effect of infrared and X-ray radiation on the production of reactive oxygen species in blood and induction of cytogenetic damage in the bone marrow of mice in vivo

The goal of the present work was to study the effect of infrared light (IRL) at a wavelength of 850 nm modulated by a frequency of 101 Hz with a mode of power 22 mW/cm2 and X-rays with a voltage of 200 kV at a dose rate of 1 Gy/min on the production of reactive oxygen species (ROS) in blood cells using luminol-dependent chemiluminescence, as well as on the induction of a cytogenetic damage in bone marrow cells of mice by the in vivo micronucleus test. The experiments performed have shown: 1) the level of the ROS production in blood of the mice exposed to IRL and X-rays at an adapting dose of 0.1 Gy reaches the peak value after 0.5 h and drops to the ROS level in untreated animals 5 h after either exposure; 2) irradiation of mice with IRL and X-rays at a dose of 0.1 Gy induces adaptive responses both in blood cells and bone marrow cells of mice. These adaptive responses were revealed only 5 h after both exposures, when the level of ROS production decreased to the ROS level in untreated animals; they are equal in magnitude and dynamics and persist up to 2 months.     

The cytogenetic effect of natural modifiers of mutagenesis in a human lymphocyte culture: the modification of the mutagenic effect by recombinant interferon in vitro in the lymphocytes of bronchial asthma patients and of healthy donors]

The significant protective effect of recombinant interferon in the cultures of lymphocytes of healthy donors and patients with bronchial asthma has been revealed. The cytogenetic damage were stimulated by alkylating agents thioTEPA and photrin during their administration at the stages Gi-S of the cell cycle. No differences were revealed in the action of mutagens and protector in the patients and healthy persons.     

The cytogenetic effect of bleomycin on human peripheral lymphocytes in vitro and in vivo.

The cytogenetic effect of bleomycin (BLM) in human lymphocytes was studied after exposure to different doses during the G0 and G2 phases. BLM produced a marked specific effect on the cell cycle. The main aberration types after exposure in tg0 were dicentrics and deletions; and after exposure in G2, open chromatid breaks. A linear dose--response was calculated for all these aberration types as well as for the number of aberrant cells. In the G2 experiments, partially and totally pulverized cells also increased linearly with dose. The intercellular distributions of the most frequent aberration types after exposure in G0 and G2--the dicentrics and chromatid breaks, respectively--showed over-dispersion. These results show that the cytogenetic effect of BLM may be compared with that of densely ionizing irradiation. Preliminary results of chromosome analysis of three cancer patients in the course of BLM therapy showed effects similar to those in the G0 experiments.