Drosophila melanogaster (Oregon-R, Oak Ridge strain) males, 19 to 21 hours old, were X-rayed with a total dose of 1000r. or 3000 r. given in two equal fractions of 500 r. or 1500 r. at a dose rate of 500r. per minute, except for Experiment #2 in which they were given a single dose of 1000 r. at 24 +/- 1 degree C in several gas environments, with a time interval of 40 minutes between the two doses. At each Change of gas(es),the system was evacuated to remove all gases, then Hushed with helium for 1 minute. Tests using CO were carried out in the dark and the others m the light, both at 1 atmosphere of the gas or gas mixture. In order to study the genetic radiation damage and its modification by several gases the frequencies of dominant lethals and translocations induced in cells which were in different stages of spermatogenesis were scored using seven sequential 2-day mating over a two-week test period. Data are prtsented which indicate that: 1) The frequency of dominant lethals increased from sperm to spermatids and meiotic cells, then decreased in spermatogonial cells which were the least susceptible to X-rays. 2) The cycle of damage for dominant lethals is similar to that for translocations, but does not coincide with it completely, and the peaks of damage for both are located in the early postmeiotic stages, and the cycle of frequencies of translocations coincides with that of percentages of sterility of F1 the coincidence frequencies between translocations and the sterility demonstrates that the mechanisms of damage for both are related, at least in part. 3) The NO effect on sperm and late spermatids is more drastic than the oxygen effect, but a major fraction of the effect is to cause the death of the sperm. 4) The carbon monoxide (CO) during radiation increase genetic damage above the other gases tested, and it is possible to conclude that the duration(s) of 4 minutes of gases in post-treatments is too short to modify the damage. 5) There are few (or no) translocations recovered from premeiotic cells. 6) The Y-chromosome was involved in 10.8% of total breaks, or about 1/4 as frequently as the two autosomes tested, and chromosomes 2 and 3 equally participated in an interchange.
Animal ; Chromosome Aberrations/radiation effects ; Drosophila ; Male ; Meiosis/radiation effects* ; Radiation Genetics* ; Spermatozoa/radiation effects* ; Time Factors

Chromosome Aberrations ; radiation effects ; DNA Damage ; radiation effects ; Electromagnetic Fields ; adverse effects ; Sister Chromatid Exchange ; radiation effects

Effects of gamma irradiation on the worm survival and chromosomal aberration of Clonorchis sinensis were studied. The metacercariae irradiated with various amounts of gamma radiation (ranging from 5 Gy to 50 Gy) were fed to rats, and the effects were compared with those of non-irradiated controls. Recovery rates of adult worms in irradiated groups were reduced gradually as increasing of the irradiation doses. No worm was recovered from rats which were fed with 50 Gy irradiated metacercariae. The chromosome number was 2n = 56 in all worms from all experimental groups. However, the groups irradiated with 20 Gy, 25 Gy or 30 Gy showed variations in the chromosome number, depending on different cells in the same individual. Radiation doses used in this study did not appear to induce chromosome aberrations, however, irradiation with 30 Gy showed slightly reduced chromosome size.
Animals ; Chromosome Aberrations/*radiation effects ; Clonorchis sinensis/*genetics/physiology/*radiation effects ; Dose-Response Relationship, Radiation ; Gamma Rays/*adverse effects ; Rats

OBJECTIVETo investigate the effects of electromagnetic radiation on the physiological indices and immune function of operators.

METHODSThe general conditions and electromagnetic radiation awareness rate of 205 operators under electromagnetic radiation were evaluated using a self-designed questionnaire. Physical examination, electrocardiography, and routine urine test were performed in these operators. Peripheral blood was collected from the operators under electromagnetic radiation for blood cell counting and biochemical testing, and their peripheral blood lymphocytes were cultured for determination of chromosomal aberrant frequency and micronucleus frequency. The data from these operators (exposure group) were compared with those of 95 ordinary individuals (control group).

RESULTSThe chief complaint of giddiness, tiredness, dizziness, and amnesia showed significant differences between the exposure group and control group (P < 0.01), and the difference in headache became larger with an increase in working years. The awareness rate of electromagnetic radiation damage was significantly higher in the exposure group than in the control group. The difference in bradycardia was significant between the two groups (P <0.01), and the incidence was higher with longer working years. Significant differences between the two groups were also found in the numbers of individuals with elevated alanine aminotransferase, total bilirubin, and direct bilirubin (P < 0.01), populations with increased lymphocyte ratio and decreased neutrophil ratio (P < 0.01), populations with positive occult blood, urobilinogen, and bilirubin tests, and the number of individuals with increased micronucleus frequency of cultured peripheral blood lymphocytes (P < 0.01). In addition, the exposure group had significantly increased complement C3 and C4 (P < 0.01), significantly increased IgG (P < 0.05), and significantly decreased IgM (P < 0.01), as compared with the control group.

CONCLUSIONElectromagnetic radiation may lead to the changes in physiological indices, genetic effects, and immune function and affect the health and immune function in operators. The adverse effects are increased as the working years increase. So it is important to strengthen occupational protection of operators under electromagnetic radiation.

Adult ; Chromosome Aberrations ; radiation effects ; Electromagnetic Radiation ; Female ; Humans ; Lymphocytes ; radiation effects ; Male ; Middle Aged ; Occupational Exposure ; adverse effects ; Young Adult

OBJECTIVETo explore the dose-effect relationship between premature chromosome condensation induced by Calyculin A and irradiation dose.

METHODSThe human peripheral blood was irradiated by (137)Cs gamma radial. The irradiation dose included 0, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0 Gy. The premature chromosome condensation induced by Calyculin A was observed, and dyed by centromeric banding.

RESULTSThere was the quadratic relation between the total aberration, fragment, dicentric+centric ring (dic+r) ration and irradiation dose.

CONCLUSIONPremature chromosome condensation induced by Calyculin A can be used as a biodosimetry.

Cell Line ; Chromosome Aberrations ; radiation effects ; Chromosome Banding ; Chromosomes ; radiation effects ; Dose-Response Relationship, Radiation ; Female ; Gamma Rays ; adverse effects ; Humans ; Lymphocytes ; radiation effects ; Male ; Oxazoles ; pharmacology ; Young Adult

To investigate hematopoiesis and cytogenetics changes in staff of interventional radiology.A total of 121 intervention radiation workers, 245 common radiation workers and 100 medical personnel (healthy control) without exposure to radiation were enrolled in the study. The peripheral lymphocyte chromosomal aberrations and micronucleus were detected, and the result of white blood cells examination was analyzed.Compared with common radiation group and healthy control group, decreases in white blood cells count, neutrophil ratio, and increase in lymphocyte ratio were observed in intervention radiation group (all<0.05). Intervention radiation group had higher chromosome aberration rate and micronuclear rate than common radiation group and healthy control group (all<0.05). Most common chromosome aberrations were dicentric chromosome, acentric ring, fragments and minute chromosome. Abnormal rates in chromosome aberration and micronucleus rates were increased with the rise of length of service, but no statistically significant difference was observed (>0.05).Long term exposure to ionizing radiation may lead to changes in the human hematopoietic system and cause human chromosome aberration, and the severity of such injuries may be associated with the dose of ionizing radiation.
Adult ; Chromosome Aberrations ; radiation effects ; Dose-Response Relationship, Radiation ; Female ; Hematopoiesis ; radiation effects ; Humans ; Leukocyte Count ; statistics & numerical data ; Leukocytes ; pathology ; radiation effects ; Lymphocytes ; pathology ; radiation effects ; ultrastructure ; Male ; Micronuclei, Chromosome-Defective ; radiation effects ; Occupational Exposure ; adverse effects ; Radiation Exposure ; adverse effects ; statistics & numerical data ; Radiation, Ionizing ; Radiologists ; statistics & numerical data ; Time Factors

OBJECTIVETo study that low-intensity microwave whether or not enhances the genotoxic effects of mitomycin C(MMC) on human lymphocytes.

METHODSSingle strand DNA breaks and chromosomal aberrations were measured by comet assay and cytokinesis-blocked micronucleus(CBMN) test in vitro when human lymphocytes were exposed to 2,450-MHz microwave (5.0 mW/cm2) alone and in combination with mitomycin C.

RESULTSIn the comet assay, the average comet lengths of microwave group[(29.1 +/- 8.1) micron in male and (25.9 +/- 7.5) micron in female] were not significantly different from those of control groups [(26.3 +/- 6.6) and (24.1 +/- 4.3) micron respectively] (P > 0.05). The average comet lengths of MMC group(0.0125, 0.0250, 0.0500, 0.1000 microgram/ml) were significantly longer than those of control groups (P < 0.01) and were increased with the dose of MMC. The average comet lengths of microwave combined with MMC (MW + MMC) also were increased with the doses of MMC and were significantly longer than those of control groups (P < 0.01). When MMC was > or = 0.0250 microgram/ml, microwave and MMC synergistically increased the single strand DNA breaks. In the micronucleus test, the average micronucleus rates of microwave groups were not higher than those of control groups (P > 0.05). The average micronucleus rates of MMC groups and MW + MMC groups were significantly higher than those of control groups (P < 0.01) when MMC was > or = 0.0500 microgram/ml. The average micronucleus rates of MW + MMC groups seemed higher than those of corresponding MMC groups, however the difference was not significant (P > 0.05).

CONCLUSIONLow-intensity(2,450-MHz) microwave did not induce DNA and chromosome damages on human lymphocytes, but enhanced the effects of DNA breaks induced by MMC.

Chromosome Aberrations ; Comet Assay ; DNA Breaks, Single-Stranded ; Female ; Humans ; Lymphocytes ; drug effects ; radiation effects ; ultrastructure ; Male ; Micronuclei, Chromosome-Defective ; Microwaves ; adverse effects ; Mitomycin ; toxicity

When cells are exposed to a low dose of a mutagenic or clastogenic agent, they often become less sensitive to the effects of a higher dose administered subsequently. Such adaptive responses were first described in Escherichia coli. Studies on mammalian cells have been limited to human lymphocytes exposed to low doses of an alkylating agent. In this study, the adaptive response to 1 cGy of gamma rays was investigated in human tumor cells using two human hepatoma cell lines, Hep G2 and Hep 3B. Experiments were carried out by delivering 1 cGy followed by 50 cGy of gamma radiation and chromatid breaks were scored as an endpoint. The results of this study indicate that prior exposure to 1 cGy of gamma rays reduces the number of chromatid breaks induced by subsequent higher doses (50 cGy). The time necessary for the expression of the adaptive response was determined by varying the time interval between the two doses from 1 hour to 72 hours. In G2 chromatids, the adaptive response was observed both at short time intervals, as early as 1 hour, and at long time intervals. In S chromatids, however, the adaptive response was shown only at long time intervals. When 3-aminobenzamide, an inhibitor of poly (ADP-ribose) polymerase, was added after 50 cGy, adaptive responses were abolished in all the experimental groups. Therefore, it is suggested that the adaptive response can be observed in human hepatoma cell lines, which is first documented through this study.
*Adaptation, Physiological ; Carcinoma, Hepatocellular/genetics ; Chromosome Aberrations ; *Gamma Ray ; Human ; Liver Neoplasms/genetics ; Radiation Tolerance/*physiology ; Support, Non-U.S. Gov't ; Tumor Cells, Cultured/*radiation effects

The mutagenic effects of microwave and chromium trioxide (CrO(3)) on Vicia faba root tip were studied. Micronucleus assay and chromosomal aberration assay were used to determine the mitotic index, the micronucleus frequency and chromosomal aberration frequency of Vicia faba root tip cells induced by microwave and CrO(3). The results showed that the micronucleus frequency decreased, and that the mitotic index and chromosomal aberration frequency showed linear dose responses to CrO(3), in treatment of microwave for 5 s. In microwave of 25 s, the mitotic index decreased, the micronucleus frequency and chromosomal aberration frequency increased with increase of CrO(3) concentration. We concluded that microwave and CrO(3) had antagonistic effect on the mitotic index of Vicia faba root tip cells, but had synergetic effect on micronucleus frequency and chromosomal aberration frequency of Vicia faba root tip cells.
Cells, Cultured ; Chromium Compounds ; toxicity ; Chromosome Aberrations ; drug effects ; radiation effects ; Chromosomes, Plant ; drug effects ; radiation effects ; Dose-Response Relationship, Drug ; Dose-Response Relationship, Radiation ; Micronucleus Tests ; Microwaves ; adverse effects ; Plant Roots ; drug effects ; genetics ; radiation effects ; Vicia faba ; drug effects ; genetics ; radiation effects

OBJECTIVETo explore association genetic polymorphism of XPD with chromosomal damage in workers exposed to radiation.

METHODS182 workers exposed to radiation for at least one year with chromosomal damage were selected as cases based on a general health examination for all workers exposed to radiation in Tangshan city. The control group without chromosomal damage was matched to case by age (within 5 years), sex, work unit, type of exposed to radiation, cumulate serve length (within 1 year) according to 1:1. The micro whole blood cultivation was used for the chromosome analysis. The chromosome aberration type and rate were observed and counted. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to examine the genotype of three XPD loci (751, 312 and 156).

RESULTSThe frequency of XPD 751 AA in cases was higher than that in controls (P < 0.05). The frequency of 751 allele in case group was statistically higher than that in the control groups (P < 0.05). No statistical difference was found in the frequencies of XPD 312 genotype and allele between the case and control group (P > 0.05). 156 mutant gene type in case group was higher than that in the control groups. The frequency of 156 A allele in case group were higher than that of the control groups (P < 0.05). The frequency of genotype with both 751AA and 156CA or 751AA and 156AA was higher in cases than that of controls (P < 0.05).

CONCLUSIONXPD 751AA genotype is a possible risk factor for radiation-induced chromosomal damage. XPD 156 mutant gene type is a possible risk factor for radiation-induced chromosomal damage. Individuals with both XPD 751AA and 156 (CA+AA) genotypes are susceptible to radiation-induced chromosomal damage. No association of XPD 312 polymorphism with radiation-induced chromosomal damage is found.

Adult ; Case-Control Studies ; Chromosome Aberrations ; radiation effects ; Female ; Genetic Predisposition to Disease ; Humans ; Male ; Middle Aged ; Occupational Exposure ; adverse effects ; Polymorphism, Restriction Fragment Length ; Radiation ; Xeroderma Pigmentosum Group D Protein ; genetics ; Young Adult