• Radiation Oncology Journal
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• v.18 no.2
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• pp.138-149
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• 2000

Purpose : It was studied that the relationship between radiation dose, dose rate and the frequency of chromosomal aberrations in peripheral lymphocytes. Methods and Materials : Peripheral lymphocytes were irradiated in vitro with 6 MeV X-ray at dose ranges from 50 cGy to 800 cGy. The variations of the frequency of chromosomal aberrations were observed according to different radiation dose rate from 20 cGy/min to 400 cGy/min at constant total dose of 400 cGy which it was considered as factor to correct biological radiation dose measurement. Results : The yields of lymphocytes with chromosomal aberrations (dicentric chromosome, ring chromosome, acentric fragment pairs) are 0% at 50 cGy, 9% at 100 cGy, 20% at 200 cGy, 27% at 300 cGy, 55% at 400 cGy, 88% at 600 cGy, and 100% at 800 cGy. The value of Ydr is 0.000 at 50 cGy, 0.093 at 100 cGy, 0.200 at 200 cGy, 0.354 at 300 cGy, 0.612 at 400 cGy, 2.040 at 600 cGy, and 2.846 at 800 cGy. The relationship between radiation (D) and the frequency of dicentrlc chromosomes and ring Chromosomes (Ydr) can be expressed as Ydr=0.188${\times}$10$^{-2}$ D/Gy+0.422${\times}$10$^{-4}$/Gy$^{2}$${\times}$D$^{2}$ The Value of Qdr is 0.000 at 50 cGy, 1.000 at 100 cGy, 1.000 at 200 cGy, 1.333 at 300 cGy, 1.118 at 400 cGy, 2.318 at 600 cGy, and 2.846 at 800 cGy. When 400 cGy is irradiated with different dose rate each of 20, 40, 60, 80, 100, 160, 240, 320, and 400 cGy/min, Ydr is each of 0.982, 0.837, 0.860, 0.732, 0.763, 0.966, 0.909, 1.006, and 0.806, and Qdr is each of 1.839, 1.555, 1.654, 1.333, 1.381, 1.750, 1.6000, 1.710, and 1.318. Conclusion : There are not the significant variations of Ydr and Qdr values according to different dose rate. And so radiation damage is influenced by total exposed radiation doses and is influenced least of all by different dose rate when it is acute single exposure.

• Journal of Radiation Protection and Research
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• v.18 no.2
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• pp.1-16
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• 1993

As guides to decision-making in the management of the victims in case of acute whole body or partial body radiation exposure, we studied the relationship between radiation dose and the frequency of chromosomal aberrations observed in peripheral lymphocytes that were irradiated in vitro with $^{60}Co\;{\gamma}-rays$ at doses ranging from 2Gy to 12Gy. The yields of cells with unstable chromosomal aberrations (dicentric chromosomes, ring chromosomes, and acentric fragment pairs) were 32% at 2Gy, 47% at 4Gy, 80% at 6Gy, 94% at 8Gy, and 100% at 10Gy and over. Ydr, which reflect average dose to the whole body in case of acute whole body exposure, were 1.373 at 2Gy, 0.669 at 4Gy, 1.734 at 6Gy, 2.773 at 8Gy, 3.746 at 10Gy and 5.454 at 12Gy. The relationship between radiation dose (D) and the frequency of dicentric plus ring chromosomes per cell(Ydr) could be expressed as $Ydr=9.322{\times}10^{-2}/Gy {\times}D+2.975{\times}10^{-2}/Gy^2{\times}D^2$. Qdr, which are used in estimating dose of partial body exposure and dose of past exposure, were 1.166 at 2Gy, 1.436 at 4Gy, 2.173 at 6Gy, 2.945 at 8Gy, 3.746 at 10Gy and 5.454 at 12Gy. To see how confidently this dosimetry system may be used, we obtained Qdr values from those who received one fraction of homogenous partial body irradiation of 1.BGy, 2.5Gy, and 7.OGy therapeutically; in vivo Qdr values were 1.109, 1.222 and 2.222 respectively. The estimated doses calculated from these in vivo Qdr values using the equation $Qdr=Ydr/(1- e^{-Ydr})$ were 1.52Gy, 2.48Gy, and 6.54Gy respectively, which were very close to the doses actually given.

• Journal of Life Science
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• v.19 no.4
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• pp.449-456
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• 2009

Murine Neuro-2a (N2a) cells have been widely used for the investigation of neuronal differentiation, trophic interaction and neurotoxic effects of various compounds and their associated mechanisms. N2a cells have many genomic variations such as gains or losses in DNA copy number, similar to other neuroblastoma cells, and no systematic or high-resolution studies of their genome-wide chromosomal aberrations have been reported. Presently, we conducted a systematic genome-wide determination of chromosomal aberrations in N2a cells using a high-throughput, oligonucleotide array-based comparative genomic hybridization (oaCGH) technique. A hidden Markov Model was employed to assign each genomic oligonucleotide to a DNA copy number state: double loss, single loss, normal, gain, double gain and amplification. Unlike most neuroblastoma cells, Mycn amplification was not observed in N2a cells. In addition, these cells showed gain only in the neuron-derived neurotrophic factor (NF), while other neurotrophic factors such as glial line-derived NF and brain-derived NF presented normal copy numbers. Chromosomes 4, 8, 10, 11 and 15 displayed more than 1000 aberrational oligonucleotides, while chromosomes 3, 17, 18 and 19 displayed less than 20. The largest region of gain was located on chromosome 8 and its size was no less than 26.7 Mb (Chr8:8427841-35162415), while chromosome 4 had the longest region of single deletion, with a size of 15.1 Mb (Chr4:73265785-88374165).

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.125-132
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• 1995

The purpose of this study was to establish mononuclear cell cultures such as lymphocytes or buffy coat for the biological dosimetry of in vitro Irradiation of the radionuclide Tc-99m in order to exclude the effect of residual doses seen in the cultures of whole blood. Biological do simetry of Tc-99m on cultured mononuclear cells at doses ranging from 0.05 to 6.00 Gy, by scoring unstable chromosomal aberrations(Ydr) observed in cultured lymphocytes, were performed using peripheral venous blood of healthy normal person. The results showed that; (1) In vitro irradiation of radioisotope in separated lymphocyte or buffy coat showed trace amount of residual doses of isotope after washing. Residual doses of isotopes are increased in proportion to exposed time and irradiated dose without difference between I-131 and Tc-99m. (2) We obtained these linear-quadratic dose response equations in lymphocyte and buffy coat culture after in vitro irradiation of Tc-99m, respectively (Ydr = 0.001949 $D^2$ +0.006279D + 0.000185; Ydr= 0.002531 $D^2$-0.003274 D+0.003488). In conclusion, the linear quadratic dose-response equation from in vitro irradiation of Tc-99m with lymphocyte and buffy coat culture was thought to be useful for assessing Tc-99m induced biological effects. And mono-nuclear cell cultures seem to be the most appropriate experimental model for the assessment of biological dosimetry of internal irradiation of radionuclides.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.1
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• pp.59-79
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• 2021

Objectives This study was performed to observe the genotoxic effect of the ChondroT. Methods To evaluate the genotoxicity of ChondroT, an experiment of bacterial reverse mutation test, in vitro mammalian chromosomal aberration test and mammalian erythrocyte micronucleus test in mouse was conducted. Results TA98, TA100 and TA1537 strains in the absence of metabolic activation system (S9 mix), the number of revertant colonies being greater than 2-fold of the respective negative control value. Both in -S9 mix and +S9 mix, the frequencies of aberration cells with structural aberration and numerical aberrations of chromosome were less than 5%. There was no increase of polychromatic erythrocyte with one or more micronuclei at any dose of test substance compared to the negative control group (p<0.05). Conclusions In TA98, TA100 and TA1537 strains in the absence of metabolic activation system (S9 mix), the number of revertant colonies was greater than 2-fold of the respective negative control value, showing positive results. ChondroT was considered to be non-clastogenic to Chinese hamster lung (CHL/IU) cells under the present experimental condition. and ChondroT was determined not to induce an increased frequency of micronuclei in the bone marrow cells of male ICR mice under the present experimental condition.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2001.10a
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• pp.61-86
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• 2001

All cancers are caused by abnormalities in DNA sequence. Throughout life, the DNA in human cells is exposed to mutagens and suffers mistakes in replication, resulting in progressive, subtle changes in the DNA sequence in each cell. Since the development of conventional and molecular cytogenetic methods to the analysis of chromosomal aberrations in cancers, more than 1,800 recurring chromosomal breakpoints have been identified. These breakpoints and regions of nonrandom copy number changes typically point to the location of genes involved in cancer initiation and progression. With the introduction of molecular cytogenetic methodologies based on fluorescence in situ hybridization (FISH), namely, comparative genomic hybridization (CGH) and multicolor FISH (m-FISH) in carcinomas become susceptible to analysis. Conventional CGH has been widely applied for the detection of genomic imbalances in tumor cells, and used normal metaphase chromosomes as targets for the mapping of copy number changes. However, this limits the mapping of such imbalances to the resolution limit of metaphase chromosomes (usually 10 to 20 Mb). Efforts to increase this resolution have led to the "new"concept of genomic DNA chip (1 to 2 Mb), whereby the chromosomal target is replaced with cloned DNA immobilized on such as glass slides. The resulting resolution then depends on the size of the immobilized DNA fragments. We have completed the first draft of its Korean Genome Project. The project proceeded by end sequencing inserts from a library of 96,768 bacterial artificial chromosomes (BACs) containing genomic DNA fragments from Korean ethnicity. The sequenced BAC ends were then compared to the Human Genome Project′s publicly available sequence database and aligned according to known cancer gene sequences. These BAC clones were biotinylated by nick translation, hybridized to cytogenetic preparations of metaphase cells, and detected with fluorescein-conjugated avidin. Only locations of unique or low-copy Portions of the clone are identified, because high-copy interspersed repetitive sequences in the probe were suppressed by the addition of unlabelled Cotl DNA. Banding patterns were produced using DAPI. By this means, every BAC fragment has been matched to its appropriate chromosomal location. We have placed 86 (156 BAC clones) cytogenetically defined landmarks to help with the characterization of known cancer genes. Microarray techniques would be applied in CGH by replacement of metaphase chromosome to arrayed BAC confirming in oncogene and tumor suppressor gene: and an array BAC clones from the collection is used to perform a genome-wide scan for segmental aneuploidy by array-CGH. Therefore, the genomic DNA chip (arrayed BAC) will be undoubtedly provide accurate diagnosis of deletions, duplication, insertions and rearrangements of genomic material related to various human phenotypes, including neoplasias. And our tumor markers based on genetic abnormalities of cancer would be identified and contribute to the screening of the stage of cancers and/or hereditary diseases

• Clinical and Experimental Pediatrics
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• v.45 no.3
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• pp.395-400
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• 2002

Recently, the increasing use of antenatal high resolutional ultrasonographic studies, and the increasing expertise of sonographers have contributed to the more frequent prenatal detecton of fetal hepatic calcification. Fetal hepatic calcification can arise from peritoneal, ischemic, infectious, neoplastic, and idiopathic causes. There are many reports that the prognosis is good in isolated fetal hepatic calcification without chromosomal aberrations, associated congenital malfomations or other organ abnormalities. We report one case of fetal hepatic calcification diagnosed by prenatal ultrasonography at gestational age of 27 weeks, without chromosomal abnormalities or other associated organ abnormalities, showing good prognosis.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3559-3567
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• 2016

Background: In recent years, there has been considerable research on recycling of agro-industrial waste for production of bioactive compounds. The food processing industry produces large amounts of citrus peels that may be an inexpensive source of useful agents. Objective: The present work aimed to explore the phytochemical content, antioxidant, anticancer, antiproliferation, and antigenotxic activities of lemon, grapefruit, and mandarin peels. Materials and Methods: Peels were extracted using 98% ethanol and the three crude extracts were assessed for their total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant activity using DPPH (1, 1-diphenyl-2-picrylhydrazyl). Their cytotoxic and mitogenic proliferation activities were also studied in human leukemia HL-60 cells and mouse splenocytes by CCK-8 assay. In addition, genotoxic/antigenotoxic activity was explored in mouse splenocytes using chromosomal aberrations (CAs) assay. Results: Lemon peels had the highest of TPC followed by grapefruit and mandarin. In contrast, mandarin peels contained the highest of TFC followed by lemon and grapefruit peels. Among the extracts, lemon peel possessed the strongest antioxidant activity as indicated by the highest DPPH radical scavenging, the lowest effective concentration 50% ($EC_{50}=42.97{\mu}g\;extract/mL$), and the highest Trolox equivalent antioxidant capacity (TEAC=0.157). Mandarin peel exhibited moderate cytotoxic activity ($IC_{50}=77.8{\mu}g/mL$) against HL-60 cells, whereas grapefruit and lemon peels were ineffective anti-leukemia. Further, citrus peels possessed immunostimulation activity via augmentation of proliferation of mouse splenocytes (T-lymphocytes). Citrus extracts exerted non-cytotoxic, and antigenotoxic activities through remarkable reduction of CAs induced by cisplatin in mouse splenocytes for 24 h. Conclusions: The phytochemical constituents of the citrus peels may exert biological activities including anticancer, immunostimulation and antigenotoxic potential.

• Clinical and Experimental Reproductive Medicine
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• v.50 no.3
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• pp.192-199
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• 2023

Objective: This study was conducted to investigate chromosomal abnormalities and their correlations with clinical and radiological findings in females with primary amenorrhea (PA). Methods: Detailed forms were recorded for 470 females, including the construction of three-generation pedigrees. Peripheral venous blood was drawn, with informed consent, for cytogenetic analysis. Results: An abnormal karyotype was found in 16.38% of participants. The incidence of structural abnormalities (6.8%) exceeded that of numerical abnormalities (6.15%). Turner syndrome represented 45% of all numerical abnormalities. Furthermore, the Y chromosome was detected in 5% of females with PA. Among the structural chromosomal abnormalities detected (n=32) were mosaicism (25%), deletions (12.5%), isochromosomes (18.75%), fragile sites (3.12%), derivatives (3.12%), marker chromosomes (3.12%), and normal variants (29.125%). An examination of secondary sexual characteristics revealed that 29.6% of females had a complete absence of breast development, 29.78% lacked pubic hair, and 36.88% exhibited no axillary hair development. Radiological findings revealed that 51.22% of females had a hypoplastic uterus and 26.66% had a completely absent uterus. Abnormal ovarian development, such as the complete absence of both ovaries, absence of one ovary, one absent and other streak, or both streak ovaries, was observed in 69.47% of females with PA. Additionally 43.1%, 36.1%, 67.4%, and 8% of females had elevated levels of serum follicle-stimulating hormone, luteinizing hormone, thyroid-stimulating hormone, and prolactin, respectively. Conclusion: This study underscores the importance of karyotyping as a fundamental diagnostic tool for assessing PA. The cytogenetic correlation with these profiles will aid in genetic counseling and further management of the condition.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.94-99
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• 1999

Purpose: Radiation-induced chromosomal damage and apoptosis were compared in human lymphocytes. Materials and Methods: Peripheral lymphocytes from 10 normal volunteers (6 males, 4 females, age range $23{\sim}41$ years) were irradiated by gamma rays from a cell irradiator. Doses of irradiation were 0 (control), 0.18, 2, 5, 10, 20 and 25 Gy. Irradiated lymphocytes were examined by metaphase analysis for chromosomal aberrations and by flow cytometry for apoptosis. Results of both studies were compared according to dose. Results: Number of dicentric and ring chromosomes (D+R) was $0.5{\pm}0.53$ at baseline, which was significantly increased after radiation according to the dose. The fraction of cells showing annexin V-fluorescein isothiocyanate uptake was $0.51{\pm}$0.39%, which increased to $3.58{\pm}1.85%$ by 2 Gy irradiation, and then decreased. The fraction of cells showing propidium iodide (PI) uptake was $0.52{\pm}0.12%$, which significantly increased according to dose (upto $15.64{\pm}5.99%$ by 20 Gy irradiation). D+R and PI uptake were well correlated (r=0.84, p<0.001). Conclusion: Radiation-induced chromosomal aberration was correlated to nuclear uptake of PI, a marker of late apoptosis.