OBJECTIVETo investigate the material foundation of the fusion of bcr and abl genes, and to explore the pathogenesis of chronic myeloid leukemia.

METHODSBy FISH combined with laser confocal scanning microscopy, the three-dimension (3D) distribution of bcr and abl genes in the interphase nuclei of normal and irradiated IM-9 cells was studied in each cell cycle phases.

RESULTSabl and bcr genes distributed non-randomly in the interphase nuclei of IM-9 cells. abl gene preferably located at the outer layer and bcr near the core of the nucleus. The two genes were drawn near each other most in G(0) phase. The relative distance between the homologous genes was greater at proliferation phase than at quiescence phase. After irradiation, the relative distances from the two genes to the core and between the two genes were shortened, with the shortest distance between the two genes in S phase.

CONCLUSIONIrradiation could change the 3D-distribution of abl and bcr genes in the interphase nuclei of IM-9 cell and accelerate them to draw near each other.

Cell Nucleus ; genetics ; radiation effects ; ultrastructure ; Cells, Cultured ; Female ; Fusion Proteins, bcr-abl ; genetics ; radiation effects ; Gene Fusion ; radiation effects ; Genes, abl ; genetics ; radiation effects ; Humans ; In Situ Hybridization, Fluorescence ; Interphase ; genetics ; radiation effects ; Lymphocytes ; ultrastructure ; Microscopy, Confocal ; Proto-Oncogene Proteins c-bcr ; genetics ; radiation effects

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

The purpose of this study was to estimate predictive markers of intrinsic radiosensitivity in individuals who were exposed to occupational or environmental radiation. Throughout this process, the actual biohazard risks and base-line chromosome damage were evaluated in human population. Further studies were carried out to provide evidence for the existence of individual variations in age-dependent responses through micronuclei (MN) assay.Spontaneous frequencies not only vary greatly between individuals, but also working or living areas. It was shown that the increased level of spontaneous cell with MN was observed with increasing age. The relationship between radiosensitivity and the increased spontaneous level of MN may be in an inverse proportion. Ionizing radiation may be targeted mutagenic effects at the usual exposures of background levels that populations were exposed. Age and gender are the most important demographic variables in determining the MN index with frequencies in females, which were greater than those in males. The main life-style factors influencing the MN index in subjects were correlated significantly and positively with smoke. The results showed that an indicator of the genetic damaged rate in MN index in human populations significantly correlated with age, sex and life-style factors. So far, it is evident that with regard to the application of MN assay all future studies have to take into account the influence of age, gender, and life-style.In Conclusion, using micronuclei assay technique a large population can be easily monitored. This study illustrated that the MN assay may provide a high potential to ensure appropriate quality control and standard documentation protocol that can be used to monitor a large population exposed to radiation epidemiologically.
Adolescent ; Adult ; Age Factors ; Aged ; Background Radiation/*adverse effects ; Chromosomes, Human/radiation effects ; Environmental Exposure/*adverse effects ; Female ; Humans ; Korea ; Life Style ; Lymphocytes/*radiation effects/ultrastructure ; Male ; Micronuclei, Chromosome-Defective/*radiation effects ; *Micronucleus Tests ; Middle Aged ; Occupational Exposure/*adverse effects ; Radiation Tolerance/*physiology ; Sex Factors