• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.205-210
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• 2002

In irradiated human lymphocytes, translocation of chromosome has been more frequently observed than dicentric chromosome. Differences in the misrepair process leading to translocation and dicentric chromosomes may explain the above observations. In order to find out whether dicentric and translocation are originated from different mechanism, the frequencies of radiation induced translocation and dicentric in lymphocytes were examined following treatment of irradiated lymphocytes with two DNA repair inhibitors, 3AB for inhibition of poly(ADP-ribose) synthesis and Ara C for inhibition of DNA-polymerase $\alpha$. Ara C potentiated the frequencies of radiation induced dicentric and translocation. 3AB also potentiated the frequencies of radiation induced dicentric, but not translocation. These results suggest the potential differences in the mechanisms in the formation of translocation and dicentric chromosomes.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3123-3128
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• 2024

The dicentric chromosome assay is a gold standard method to estimate radiation exposure by calculating the ratio of dicentric chromosomes existing in cells. The objective of this study was to propose an automatic dicentric chromosome discrimination method based on deep convolutional neural networks using radiation exposure patient data. From 45 patients with radiation exposure, conventional Giemsa-stained images of 116,258 normal and 2800 dicentric chromosomes were confirmed. ImageNet was used to pre-train VGG19, which was modified and fine-tuned. The proposed modified VGG19 demonstrated dicentric chromosome discrimination performance, with a true positive rate of 0.927, a true negative rate of 0.997, a positive predictive value of 0.882, a negative predictive value of 0.998, and an area under the receiver operating characteristic curve of 0.997.

• Environmental Mutagens and Carcinogens
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• v.17 no.1
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• pp.12-16
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• 1997

Chromosome rearrangement induced by bleomycin were identified by fluorescence in situ hybridization with probe for chromosome 4. The frequency of color junctions, translocations, dicentric and acenttic fragments increased with bleomycin dose. Different types of balanced translocation and dicentric were scored and compared. The frequency of cells exhibiting multiple aberration was higher compared to that of cells exposed to Gamma radiation suggesting that effect of bleomycin might be similar to that of high LET radiation.

• Environmental Mutagens and Carcinogens
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• v.16 no.2
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• pp.88-96
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• 1996

Fluorescence in situ hybridization (FISH) with the DNA probe for human chromosome 4 was used to analyse in vitro radiation induced chromosome rearrangement in peripheral lymphocyte. Translocations, dicentrics, acentrics and color junctions involving the painted chromosome were scored according to the Protocol for Aberration Identification and Nomenclature Terminology (PAINT) system. The frequency of chromosome rearrangements including reciprocal translocation, dicentric, acentric fragment and color junction increased with radiation dose. The frequency of dicentric chromosome reduced by the fixation time following irradiation, whereas that of translocation was relatively persistent. The applicability of FISH for scoring stable translocation for biological dosimetry was demonstrated.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.1
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• pp.6-10
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• 2009

Ring chromosome occurs when both telomeres of a chromosome are lost and the remaining portion of the chromosome circularizes to re-establish chromosome stability. This abnormal structure shows mitotic instability unlike the normal chromosomes, causing problems during mitosis. Here, we report one case of "chromosome 4 ring syndrome" on a 6-month-old male patient with growth retardation. Ring chromosome, monosomy, dicentric chromosome were shown by conventional chromosome analysis using peripheral blood. Peripheral blood was used and incubated for 72 hours for chromosome analysis. 3 probes (LSI WHS SpectrumOrange/CEP 4 SpectrumGreen, 4p subtelomere probe, 4q subtelomere probe) were used to detect the origin and breakpoint of ring chromosome 4 by FISH (fluorescense in situ hybridization) technique.

• Environmental Mutagens and Carcinogens
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• v.19 no.1
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• pp.14-19
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• 1999

Chromosome rearrangements induced in human lymphocyte after in vitro exposure to chromium were analysed by the use of fluorescence in situ hybridization(FISH) with triple combination of composite whole chromosome-specific probe for chromosome 1, 2 and 4. Chromosome aberrations was scored by the Protocol for Aberration Identification and Nomenclature Terminology (PAINT). Stable translocation was the most frequent type of aberrations and dicentrics and insertions were also observed. Chromium treatment enhanced the frequencies of stable translocations and color junctions in a dose-dependent manners, but no distinct increase of dicentrics and insertions was seen. The ratio of the yields of translocation to the yields of dicentric varied between 13 to 27. The presents results demonstrate fluorescent in situ hybridization (FISH) is useful for detecting chromosomal rearrangements induced by chromium.

• Korean Journal of Veterinary Research
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• v.29 no.2
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• pp.51-57
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• 1989

This study was performed to investigate the toxicity of ochratoxin A (OA) to the chromosomes of $K_{562}$ tumor cell-line in vitro. The results of this experiment were as follows: 1) Chromosomes of $K_{562}$tumor cell-line resulted in pseudotriploidy on the control group. Chromosomes of $K_{562}$ tumor cell-line treated with OA resulted in heteroploidy compared with the control group. The mean number of chromosomes in the karyotype of the control group (60) were 7 in the A group, 5 in the B group, 20 in the C+X group, 7 in the D group, 9 in the E group, 6 in the F group, and 6 in the G+Y group respectively. The number of chromosomes were increased as follows: Treating with $0.7{\mu}M$ OA, the number of chromosomes were increased one in E and F group, two in G+Y group compared with control group. In treated with $1.5{\mu}M$ OA, the increasing number of chromosome was one in E and F group. In treated with $3{\mu}M$ OA, E and F group was increased one and G+Y group were increased two chromosomes compared with control group. But in treated with $6{\mu}M$ OA, the number of chromosome in G+Y group was decreased one. 2) $K_{562}$ tumor cell line treated with OA showed Philadelphia-Chromosome in the long arm of the G group karyotype chromosome. The rate of chromosome aberration in $K_{562}$ tumor cell-line treated with OA was 77% in $0.7{\mu}M$ OA group, 71% in $1.5{\mu}M$ OA group, 82% in $3{\mu}M$ OA group and 94% in $6{\mu}M$ OA group respectively. The rate of chromosome aberration of $K_{562}$ tumor cell-line treated with OA was high in the high dose level of OA, and chromosome aberration of $K_{562}$ tumor cell-line treated with OA showed deletion, minute, dicentric-chromosome and translocation in the long arm of the C-group karyotype. As a result of this study, the toxicity of OA showed deletion, minute, dicentric-chromosome and translocation in the long arm of the C-group karyotype, and then, the toxicity of OA resulted in the damage to RNA and protein synthesis in $K_{562}$ tumor cell-line, and the C-group karyotype of $K_{562}$ tumor cell-line was target of the toxicity of OA.

• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.109-115
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• 1998

Fluorscence in situ hybridization with chromosome-specific probe has been shown to be a valid and rapid method for detection of chromosome rearrangements induced by chemical and physical agents. This method is useful for quantifying structural aberrations, expecially for stable ones, such as translocation and insertion, which are difficult to detect with conventional method in human lymphocyte. In order to use the FISH method as a biodosimeter for monitoring human population exposed to various chemical and physical agent, baseline level of chromosome rearragement was established. Blood from forty four healthy adults were collected and analysed with whole chromosome-specific probes by human chromosome 1,2 and 4. The frequencies of stable translocation were 2.45 per 100 cell equivalent and those of insertion, color juction, acentric and dicentric were 0.32, 3.28, 0.23 and 0.27 per 100 cell equivalent respectively. The frequencies of chromosome rearragements increased with age in both sexes except for dicenrics. From above result, stable aberrations accumulate with age and it may reflect integrated lifetime exposure of adverse environment.

• Journal of Environmental Health Sciences
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• v.21 no.3
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• pp.67-76
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• 1995

The frequencies of chromosome aberrations and sister chromatid-exchanges in peripheral blood lymphocyte of 44 nurses handling anticancer drugs were compared with those in 44 age-match controls. The frequencies of dicentric chrdmosome were $2.4\times 10^{-3}$ in the exposed and $0.5\times 10^{-3}$ in the control. The frequencies of sister cromatid exchanges in the exposed were slightly higher (5.68 SCEs/cell) than those in the control (5.04 SCEs/cell). The frequencies of chromosome aberrations and sister cromatid exchanges were not associated with duration of drug handling and types of anticancer drugs, but associated with use of safety cover.

• The Korean Journal of Zoology
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• v.13 no.1
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• pp.29-33
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• 1970

The conclusions established in the present study on the chromosomes in vitro of the uterine carcinomas of Korean women are as follows: 1. The pattern of the distribution of chromosome number in uterine carcinoma cells was quite different from that of normal cells, and modal number of the chromosome was 45 and 46. 2. The frequency of diplochromosomes was 0.053 per cell (5.3%) and that of chromosome aberration was 0.16 per cell (16%), which are significantly higher than each of normal cells. In chromosome aberration types, chromatid and isochromatid deletions (chromatid type) and dicentric (chromosome type) were observed. 3. Idiogram analysis showed a tendency that the number of chromosomes belonging to group F increased while that of chromosomes in groups B and E decreased in total. The number of chromosomes in groups C and G in the hypodiploidy cells decreased, but it increased in the hyperdiploidy cells.