• Toxicological Research
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• v.34 no.3
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• pp.259-266
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• 2018

Glycomacropeptide (GMP), a whey protein of milk, has functions including differentiation and development of nervous system, and anticancer and antiviral effects. To develop new functions, N-acetylneuraminic acid (NANA) containing 7% sialic acid was separated from GMP to produce G-7%NANA. N-glycolylneuraminic acid (Neu5Gc) is another type of sialic acid separated from GMP, which has been linked to immune disorders and chronic inflammation-mediated diseases. Therefore, safety was a concern in the use of G-7%NANA in functional foods. To ensure safety, in this study, three genetic toxicity tests on G-7%NANA were conducted. In the reverse mutation test using Salmonella typhimurium TA98, TA100, TA1535, TA1537, and Escherichia coli WP2uvrA, and in the chromosome aberration test using CHO-K1 cells, no significant differences from negative control were found at all dose levels. Similarly, no dose-related differences were evident compared to negative control in the micronucleus test using ICR mice. There was no evidence of G-7%NANA-related genetic toxicity.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.121-122
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• 2001

According to the epidemiological studies in chromium workers, hexavalent chromium is associated with the risk of lung cancer. Genotoxicity such as chromosome aberration, and cellular oxidative damages by reactive oxygen species produced by hexavalent chromium exposure may play an important role in the carcinogenesis process. We investigated the availabilities of several kinds of biological markers to assess the genotoxicity and oxidative damages from chromium exposure in Korean chromium plating workers.(omitted)

• Journal of Genetic Medicine
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• v.9 no.1
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• pp.17-21
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• 2012

Purpose: The aim of this study was to analyze parental decisions regarding pregnancies in which the fetus had sex chromosome abnormalities (SCA) over a ten-year period. Materials and Methods: We collected and reviewed records from our hospital for 2001-2010 and a genetic specialist provided-genetic counseling. Results: We diagnosed 130 cases (0.71%) with SCA out of 18,376 prenatal cases from 2001 to 2010. We reviewed the records and the results of all pregnancies. We also included cases (n=84) of apparently normal anatomic fetuses to analyze the factors influencing parental decisions. We excluded 34 cases with an obvious anomaly or a presumably bad outcome and 12 cases that were not followed up. Forty-three couples (51.2%) continued their pregnancies while forty-one (48.8%) terminated them. Of 38 mosaicism cases, 21 (55.3%) were continued. Among the 20 pregnancies assisted by reproductive techniques, 15 (75%) were continued (P=0.02). More pregnancies were continued when genetic counseling was provided (61.9%) compared to cases in which it was not provided (19%) (P=0.01). Conclusion: Genetic counseling is important in providing appropriate information to parents. Establishing guidelines and protocols will help both obstetricians and parents to make informed decisions.

• Journal of Radiation Protection and Research
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• v.17 no.1
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• pp.21-30
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• 1992

The frequencies of KCCH cyclotron neutron (30 cGy/min) or $^{60}Co\;{\gamma}-rays$ (210 cGy/min)-induced asymmetrical interchanges (dicentrics and centric rings) and acentric fragments (deletion) at several doses were measured in the normal human peripheral blood lymphocytes Chromosome aberrations were scored at the first nitosis after stimulation with phytohemagglutinin. The neutron and y-ray data were analysed on linear, power-law, quadratic and linear-quadratic model . When the dicentrics and centric rings of ${\gamma}-rays$ datas were pooled and fitted to these model, good fits were obtained to power-law $[Y=(5.81{\pm}1.96){\times}10^6D^{1.93+0.06},\; P=0.931]$, quadratic $[Y=(3.91{\pm}0.09){\times}10^{-6}D^2,\;P=0.972]$ an linear-Quadrati model $[Y=(6.55{\pm}6.83){\times}10^{-5}D+(3.72{\pm}0.22){\times}10^{-6}D^2\; P=0.922]$, except for linear model (P=0.067) As in the case of neutron data, the best fit was obtained to the linear model $(Y=(6.12{\pm}0.17){\times}10^{-3}\;D-0.22,\;P=0.987]$ and good fits were obtained to power-law$[Y=(5.36{\pm}3.02) {\times}10^{-4}D^{1.42+0.11},\; P=0.601]$ and linear-quadratic model$[Y=(2.43{\pm}0.70){\times}10^{-3}D+(1.21{\pm}0.39){\times}10^{-7}D^2$, \;P=0.415], except for quadratic model (P<0.005). The relative biological effectiveness (RBE) of neutron compared with y-ray was estimated by best fitting model. In the asymmetrical interchanges range between 0.1 and 1.5 per cell, the RBE was found to be $2.714{\pm}0.408$.

• Clinical and Experimental Pediatrics
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• v.50 no.9
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• pp.875-881
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• 2007

Purpose : Chromosome analysis is important in genetic study and genetic counseling. This study was performed to evaluate the type and incidence of chromosome abnormalities in a single hospital for 25 years. Methods : Chromosome analyses were performed on peripheral blood lymphocytes, obtained from 4,856 patients with suspected chromosomal aberrations, referred to cytogenetic laboratory in Department of Pediatrics, Kyungpook National University Hospital from May 1981 to October 2005. Results : We analyzed 4,567 cases. Children were 3,014 cases (66.0%) and adult were 1,553 cases (34.0 %). The most common purpose of the chromosomal analysis was growth and developmental abnormality in children and infertility in adults. Total chromosomal aberration rate was 16.9% (770/4,567). Among those cases, the numerical abnormalities were 12.2% (558 cases), the structural abnormalities were 4.1% (187 cases), and others were 0.5% (25 cases). The relative frequencies of autosomal abnormalities were 6.4% (294 cases) in Down syndrome; 0.2% (7 cases) in Edwards syndrome; 0.1% (4 cases) in Patau syndrome; 0.2% (10 cases) in other abnormalities, of sex chromosome, 2.9% (131 cases) in Klinefelter syndrome; 2.2% (99 cases) in Turner syndrome; 0.2% (8 cases) in 47, XXX; 0.1% (3 cases) in 47, XYY. Among the structural abnormalities, translocation was 1.8% (84 cases), inversion was 0.8% (37 cases), deletion was 0.4% (17 cases), and insertion was 0.3% (13 cases), in order of frequency. Conclusion : In this study, the type, incidence and distribution of cytogenetic abnormalities by karyotype were reviewed. We hope that our study could be used as a basic information on the diagnosis, treatment and genetic counseling for chromosome abnormalities in Korea.

• Journal of Genetic Medicine
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• v.5 no.2
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• pp.125-130
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• 2008

Propose: To analyze the indications and cytogenetic results of midtrimester amniocentesis. Material and Methods: This study reviewed 2,523 cases of midtrimester prenatal genetic amniocentesis performed at MizMedi Hospital between January 2000 and December 2007. Results: The most frequent indication for midtrimester amniocentesis was advanced maternal age (45.9%), followed by positive serum markers (29.9%). Chromosomal aberrations were diagnosed in 110 cases (4.4%), for which numerical aberration accounted for 38 cases (34.5%), structural aberration accounted for 65 cases (59.1%), and mosaicism accounted for 7 cases (6.4%). Among the autosomal aberrations, there were 20 cases of trisomy 21 and 8 cases of trisomy 18. With respect to structural aberrations, there were 14 cases of reciprocal translocation and 8 cases of robertsonian translocation. The frequencies of chromosomal aberrations according to the indication were highest in individuals with a family history of chromosome abnormality 14.0% (8/57) followed by previous congenital anomaly 5.9% (2/34). Conclusion: Midtrimester amniocentesis is an effective tool for prenatal diagnosis. Indications such as advanced maternal age, maternal serum markers, and ultrasound are important for predicting abnormal fetal karyotypes.

• 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.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7129-7138
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• 2015

Background: The polycystic ovary syndrome (PCOS), characterized by hyperandrogenism and chronic anovulation, is a common endocrine disorder in women. PCOS, which is associated with polycystic ovaries, hirsutism, obesity and insulin resistance, is a leading cause of female infertility. In this condition there is an imbalance in female sex hormones. All the sequelae symptoms of PCOS gradually lead to cancer in the course of time. It is heterogeneous disorder of unknown etiology so it is essential to find the exact cause. Materials and Methods: In this study both invasive and non-invasive techniques were employed to establish the etiology. Diagnosis was based on Rotterdam criteria (hyperandrogenism, ovulatory dysfunction, PCOM) and multiparameters using buccal samples and dermatoglypic analysis and cytogenetic study for 10 cases and four age and sex matched controls. Results: In clinical analysis we have observed the mean value of total testosterone level was 23.6nmol/L, total hirsutism score was from 12-24, facial acne was found in in 70% patients with 7-12 subcapsular follicular cysts, each measuring 2-8 mm in diameter. In dermatoglypic analysis we observed increases in mean value ($45.9^{\circ}$) of ATD angle when compared with control group and also found increased frequency (38%) of Ulnar loops on both fingers (UU), (18%) whorls on the right finger and Ulnar loop on left finger (WU) and (16%) arches on right and left fingers (AA) were observed in PCOS patients when compared with control subjects. Features which could be applied as markers for PCOS patients are the presence of Ulnar loops in middle and little fingers of right and left hand. The buccal micronucleus cytome assay in exfoliated buccal cells, we found decrease in frequency of micronuclei and significant increases in frequency of karyolysed nuclei in polycystic ovarian syndrome patients. Chromosome aberration analysis revealed a significant increase in frequency of chromosome aberrations (CAs) in PCOS patients when compared with controls. Conclusions: From this present work it can be concluded that non-invasive technique like dermatoglypics analysis and buccal micronucleus cytome assays with exfoliated buccal cell can also be effective biomarkers for PCOS, along with increased CAs in lymphocytes as a sign of genetic instability. There is a hypothesis that micronuclei and chromosomal aberrations could have a predictive value for cancer. From this present work it can be concluded to some extent that non-invasive technique like dermatoglypics and buccal cell analysis can also be effective for diagnosis.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.259-264
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• 2002

Induction of embryogenic callus from Allium wakegi Araki explants was promoted on medium containing 2,4-D, and production of abnormal embryos from the embryogenic callus increased as 2,4-D concentration was raised. Shoot tip was found to be the best explant source for embryogenic callus formation followed in the order by bulb scale and leaf section. Medium containing 0.09 M sucrose was effective for embryogenic callus production. The regenerants from embryogenic callus on medium containing 2,4-D and BA at different concentrations was consisted of diploids, tetraploids and a few mixaploids of 2n＋4n, and their chromosomal aberration rate ranged from 8.0 to 33.3%. Frequency of chromosomal aberrants was the highest (18.7%) in the regenerants obtained from bulb scale-derived embryogenic callus among others. Plant regeneration rate was high (33.5%) from the shoot tip-derived embryogenic callus and the frequency of chromosomal aberrants was very low (7.0%). The plantlets regenerated on medium containing 0.26 M sucrose resulted in high chromosomal aberrants. The regenerants on medium containing sucrose at 0.09∼0.20 M produced chromosomal aberrants at around 15.2∼16.6%.

• Toxicological Research
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• v.34 no.4
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• pp.281-290
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• 2018

Exposure to chemical agents is an inevitable consequence of modern society; some of these agents are hazardous to human health. The effects of chemical carcinogens are of great concern in many countries, and international organizations, such as the World Health Organization, have established guidelines for the regulation of these chemicals. Carcinogens are currently categorized into two classes, genotoxic and non-genotoxic carcinogens, which are subject to different regulatory policies. Genotoxic carcinogens are chemicals that exert carcinogenicity via the induction of mutations. Owing to their DNA interaction properties, there is thought to be no safe exposure threshold or dose. Genotoxic carcinogens are regulated under the assumption that they pose a cancer risk for humans, even at very low doses. In contrast, non-genotoxic carcinogens, which induce cancer through mechanisms other than mutations, such as hormonal effects, cytotoxicity, cell proliferation, or epigenetic changes, are thought to have a safe exposure threshold or dose; thus, their use in society is permitted unless the exposure or intake level would exceed the threshold. Genotoxicity assays are an important method to distinguish the two classes of carcinogens. However, some carcinogens have negative results in in vitro bacterial mutation assays, but yield positive results in the in vivo transgenic rodent gene mutation assay. Non-DNA damage, such as spindle poison or topoisomerase inhibition, often leads to positive results in cytogenetic genotoxicity assays such as the chromosome aberration assay or the micronucleus assay. Therefore, mechanistic considerations of tumor induction, based on the results of the genotoxicity assays, are necessary to distinguish genotoxic and non-genotoxic carcinogens. In this review, the concept of threshold of toxicological concern is introduced and the potential risk from multiple exposures to low doses of genotoxic carcinogens is also discussed.