• Radiation Oncology Journal
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• v.11 no.1
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• pp.43-50
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• 1993

We evaluated frequency and types of chromosomal aberrations by ionizing radiation in cancer patients treated with radiotherapy in our institution. Twenty-five patients with various types of carcinomas such as lung, uterine cervix, esophagus, rectum, head and neck and pancreatic cancers were studied immediately before and after external beam radiotherapy. The frequency of aberrant metaphase prior to treatment was $4.93{\%}$, which was higher than that of control group. Especially in lung cancer, the freuqency of aberrant metaphase was three times higher than control group. A comparison of chromosomal abnormalities observed before and after radiotherapy demonstrated that proportion of aberrant rnetaphases was significantly inreased to $22.13{\%}$. Major chromosomal aberrations like structural abnormalities showed remarkalbe increase from 65.45 to $88.45{\%}$ after the treatment. Also the numbers of chromosomal alterations per cell were increased by a factor of 6.5. Aberrations with two or more break points were more prominently increased, compared with aberrations with single break point. The number of chromosomal break points was noted to be higher than expected value in No.1, 3, 8 and 11 chromosomes and lower in No.13, 15, 17 and 21 chromosomes. Based on this study, we believe that the distribution of chromosomal breakage is related with gene and chromosomal rearrangement which could result in the development of cancers.

• Journal of Preventive Medicine and Public Health
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• v.19 no.2 s.20
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• pp.244-251
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• 1986

Sister chromatid exchanges(SCEs) and cell cycle kinetics were proposed as a sensitive and quantitative assay for mutagenicity and cytotoxicity in short-term cultures of phytohema-gglutinin(PHA)-stimu1ated human 1ymphocytes. Therefore, this study was performed to investigate the relation between the cytotoxic effects and sister chromatid exchanges. The resultes are summarized as follows: 1) The frequency of SCEs per cell are $13.1{\pm}2.8$ in the lower concentration of $6.25{\times}10^{-9}M\;and\;75.8{\pm}8.2$ in the highest concentration of $1.00{\pm}10^{-7}M$. Mitotic index is decreased in the higher concentration of mitomycin C. The result indicates that mitomycin C led to a dose dependent increase in SCE frequency, but decease in mitotic index. 2) Chromosomal analysis was performed on metaphase cells that have divided one, two, and three or more times for cell cycle kinetics by fluorescence-plus-Giemsa(FPG) technique. According to the increased concentration of mitomycin C, the proportion of metaphase cells in the first are profoundly increased but the cells of third division are greatly decreased. 3) The frequency of SCEs per chromosome by chromosomal group are decreased gradually from A group to G group. But relationships between specific chromosomal group and SCE frequency are not found.

• Korean Journal of Medicinal Crop Science
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• v.13 no.3
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• pp.118-121
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• 2005

Karyotypes were established in seven Angelica species cultivated in Korea. The somatic chromosome numbers were 2n = 2x = 22 with the basic number of x = 11 in all Angelica plants examined. Their metaphase chromosomes ranged from 3.56 ${\mu}M$. to 8.91 x. in length. Distinctive Karyotypes were found in two species, A. tenuissima with all metacentries, K(2n) = 2x = 22m, and A. genuflexa with all subtelocentrics, K(2n) = 2x = 22st. Karyotype formulas of A. gigas, A. acutiloha, A. sinensis, A. decursiva and A. dahurica were K(2n) = 2x = 20m + 2sm, K(2n) = 2x = 12m + 10sm, K(2n) = 2x = 16m + 6sm, K(2n) = 2x = 18m + 4sm and K(2n) = 2x = 10m + 10sm + 2st, respectively. Cytological data showed that chromosomal polymorphisms within species were observed in Angelica plants compare to other regions.

• Parasites, Hosts and Diseases
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• v.26 no.2
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• pp.107-111
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• 1988

As a series of systematic classification of paramphistomes, the worms in the rumen and reticulum of 310 Korean cattle slaughtered at Chonju abattoir were collected from February 1986 to June 1987 and were classified by morphology of the worms. Afterwards, the karyotype of Fischoederius cobboldi (Poirier, 1883), which is a very rare species in Korean cattle, was studied with germ cells of the worm by means of modified air-drying method. The chromosome numbers in the haploid and diploid cells of 315 F. cobboldi were n=9 and 2n=18, respectively. The meiotic divisions were observed frequently; 1,904 haploid and 49 diploid cells were recognized. Nine pairs of mitotic chromosomes were homologous in the metaphase stage and the chromosomes were composed of seven medium-sized metacentrics (m) or submetacentrics (sm) and two small-sized submetacentrics (sm). While, meiotic metaphases were composed of seven medium and two small·sized chromosomes. The 3rd, 4th, 2nd and 5th pairs of chromosomes was metacentric having centromere indices of 40.4%, 40.0%, 39.7% and 38.9%, respectively, and the remaining ones were submetacentric with centromere indices from 32,4% to 36.2%. As a series of C-banding method, C-band was shown in centromeric region from all of the haploid germ cells, except chromosome No. 1 which included heterochromatin at the tip region. Chromosomes No, 4, 6 and 9 showed remarkable C-band distinguished from others.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.3
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• pp.223-231
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• 2003

Objective: The aim of the present study was to evaluate the clinical efficiency of fluorescent in situ hybridization (FISH) in the prenatal diagnosis of chromosomal aneuploidy. Methods: We reviewed data of 268 cases to identify women undergoing genetic amniocentesis at cytogenetic laboratory, from January 2000 to December 2002. Amniotic fluid was submitted for both rapid FISH on uncultured interphase amniocytes using a commercially available DNA probe for chromosome 13, 18, 21, X, Y and standard karyotyping on cultured metaphase amniocytes. Results from FISH and full karyotype were compared. Results: There were 251 cases (84%) normal and 17 cases (16%) abnormal in FISH results. All 17 cases of trisomy 13, 18, 21 including two cases of mosaicism and sex chromosome aneuploidies which are detected by FISH were confirmed with conventional cytogenetics and there was no false positive result. Twenty two cases had karyotypically proven abnormalities that could not have been detected by the targeted FISH. Conclusion: Interphase FISH analysis of uncultured amniotic fluid cells has been shown to be an effective and reliable technique for rapid fetal aneuploidy screening during pregnancy as an adjunctive test to conventional cytogenetics.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2961-2966
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• 2012

Extremely low frequency electro magnetic fields (EMFs) have been classified as possibly carcinogenic to humans by the International Agency for Research on Cancer. An increased number of chromosomal alterations in peripheral lymphocytes are correlated with elevated incidence of cancer. The aim of the present study was to assess occupationally induced chromosomal damage in EMF workers exposed to low levels of radiation. We used conventional metaphase chromosome aberration (CA) analysis and the micronucleus (MN) assay as biological indicators of non ionizing radiation exposure. In the present study totally 70 subjects were selected including 50 exposed and 20 controls. Informed written consent was obtained from all participants and the study was performed in accordance with the Declaration of Helsinki and the approval of the local ethical committee. A higher degree of CA and MN was observed in exposed subjects compared to controls, the frequency of CA being significantly enhanced with long years of exposure (P<0.05). Moreover increase in CA and MN with age was noted in both exposed subjects and controls, but was significantly greater in the former. The results of this study demonstrated that a significant induction of cytogenetic damage in peripheral lymphocytes of workers occupationally exposed to EMFs in electric transformer and distribution stations. In conclusion, our findings suggest that EMFs possess genotoxic capability, as measured by CA and MN assays; CA analysis appeared more sensitive than other cytogenetic end-points. It can be concluded that chronic occupational exposure to EMFs may lead to an increased risk of genetic damage among electrical workers.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.547-554
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• 2004

Telomeres are nucleoprotein structures at the ends of chromosomes consisting of tandem repeat sequences of . (TTAGGG)n. Telomeres serve as guardians of the genome, protect individual chromosomes within the nucleus, and help in meiotic pairing of homologous chromosomes. To investigate the telomere distributions of cattle and pig chromosomes, fluorescence in situ hybridization(FISH) was carried out on metaphase spreads of in vitro fibroblast cultures from Holstein and Landrace using a human telomeric DNA repeat probe. Results indicate that the distinct double spots on both ends of chromosomes of cattle and pigs were observed. In cattle, there was a random variation in the intensity of telomere signals among chromosomes. In pigs, an interstitial telomeric signal was observed on the chromosome 6q1 of all the cells examined. According to quantitative fluorescence in situ hybridization(Q-FISH) analysis, some chromosomes had consistently much more telorneres at one end of chromosomes. In general, both species had consistently much more telomeres at q-end than p-end on most of chromosomes. The relative amount of telomeres on bovine chromosomes was higher than that on pig chromosomes. In additions, Y chromosome had the highest relative amount of telorneres in cattle and pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1574-1579
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• 2006

This study was performed to determine the developmental potentials of nuclear transfer (NT) embryos using life-span extended cells transfected with a foreign gene as donor cells. A life-span extended bovine embryonic fibroblast cell line was transfected with an expression vector in which the human type II collagen (BOMAR) and ear fibroblasts were used as a donor cell. Cytogenetic analysis was performed to analyze the chromosomal abnormality of donor cells. The fusion rate of 1.8 kV/cm for $15{\mu}sec$ given twice was significantly higher than that of other groups (p<0.05) and the embryos lysed were significantly higher after 1.8 kV/cm for $20{\mu}sec$ given once compared to other groups (p<0.01). The blastocyst development in the ear cell group was statistically significant compared to both BOMAR groups (p<0.01). Both BOMAR groups cultured more than 40 passages (>40 passages) had a lower number of chromosomes; however, fresh granulosa cell (GC) and BOMAR groups cultured less than 20 passages had normal chromosome numbers. Both >40 passages BOMAR groups had numerous obscure debris in metaphase spreads. The transfected foreign gene was expressed in all BOMAR groups, but not in the GC group. Based on these results, the lower developmental potential of NT embryos using life-span extended donor cells transfected with a foreign gene might be a cause of chromosomal abnormality in donor cells.

• Clinical and Experimental Reproductive Medicine
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• v.39 no.2
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• pp.58-67
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• 2012

Objective: Previously, we identified that transketolase (Tkt), an important enzyme in the pentose phosphate pathway, is highly expressed at 2 hours of spontaneous maturation in oocytes. Therefore, this study was performed to determine the function of Tkt in meiotic cell cycle regulation, especially at the point of germinal vesicle breakdown (GVBD). Methods: We evaluated the loss-of-function of Tkt by microinjecting Tkt double-stranded RNAs (dsRNAs) into germinal vesicle-stage oocytes, and the oocytes were cultured in vitro to evaluate phenotypic changes during oocyte maturation. In addition to maturation rates, meiotic spindle and chromosome rearrangements, and changes in expression of other enzymes in the pentose phosphate pathway were determined after Tkt RNA interference (RNAi). Results: Despite the complete and specific knockdown of Tkt expression, GVBD occurred and meiosis was arrested at the metaphase I (MI) stage. The arrested oocytes exhibited spindle loss, chromosomal aggregation, and declined maturation promoting factor and mitogen-activated protein kinase activities. The modified expression of two enzymes in the pentose phosphate pathway, Prps1 and Rbks, after Tkt RNAi and decreased maturation rates were amended when ribose-5-phosphate was supplemented in the culture medium, suggesting that the Tkt and pentose phosphate pathway are important for the maturation process. Conclusion: We concluded that Tkt and its associated pentose phosphate pathway play an important role in the MI-MII transition of the oocytes' meiotic cell cycle, but not in the process of GVBD.

• Journal of Embryo Transfer
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• v.23 no.2
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• pp.119-125
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• 2008

A 3-month-old American Cocker spaniel was presented at the Veterinary Teaching Hospital, Chungbuk National University, for examination of urinary tract after dissection of vaginal mass at local clinic before 10 days. Clinical examination of the affected bitch revealed a normal sized vulva in a normal anatomical position with a grossly enlarged clitoris, which contained an os clitoris. On examinations of the genital gland, there were testis, epididymis, ductus deferens and uterus. The histology of both gonads was primarily testis. Seminiferous tubules were divided into many parts by fibrous connective tissue. A small number of spermatogonia was present, but large numbers of Leydig's cells were existed. A normal female karyotype (78, XX) was detected in metaphase spreads obtained from cultured peripheral lymphocytes. Y chromosome specific sequences were not detected in genomic DNA by PCR. After 27 months, the os clitoris was larger than 3-month-old dog and os bone was more calcified than young age. Combining the results of cytogenetic, molecular genetic and histological examinations, the dog was diagnosed as a female hermaphrodite with Sry-negative XX sex reversal.