• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.5229-5232
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• 2012

The incidence of malignant melanoma increases with age. One significiant effect of aging processes is an accumulation of oxidative damage in the genetical material. In this study, the relationship between malignant melanoma and damage in chromosomes and proliferative effectiveness of human peripheral lymphocytes were investigated by the micronucleus (MN) technique. A total of 15 malignant melanoma patients and appropriately matching 15 healthy controls were involved in the study. MN frequencies and proliferative indexes (PI) after non toxic levels of hydrogen peroxide treatment were also measured to determine damaging effect of oxidative stress in genome in addition to measuring the spontenous levels of micronuclei and PI. The patient group had a significantly higher rate of spontaneous MN than the control group (p<0.01). After treatment with $H_2O_2$, MN frequencies in the patient group was significantly decreased (p<0.01) although there was no difference between the treated and untreated results of control group (p=0.29). There was also difference (p<0.01) between the MN frequencies of the patient and the control group either in the spontaneous levels or in the $H_2O_2$ treated groups. The same significant difference persisted when the PI values were compared between patient and control groups. Increase in the MN frequency in patients could mean the alterations in the chromosomal structure which may lead to the chromosome instability and therefore genetic susceptibility to cancer. This increased number of micronuclei can also be used for cytological marker in identifying high risk cases for malignant melanoma.

• Reproductive and Developmental Biology
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• 제35권4호
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• pp.441-447
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• 2011

The study aim is to investigate the free radicals scavenging and spermatogenic potentials, as well as to analyze any reproductive toxicity of ethanolic extract of Mucuna prureins (M. pruriens) Linn. in spermatozoa, under different dosages in normal male rat. Normal rats were randomly selected and suspension of the extract was administered orally at the dosages of 150, 200 and 250 mg/kg body weight of the different groups of male rats (n=6) once in a day for 60 days and grouped as group II, III and IV respectively. Saline treated rats served as control -group I. On the $60^{th}$ day the animals were sacrificed and the epididymal sperm were subjected to various analyses like level of ROS production, LPO, enzymatic and non enzymatic antioxidant, morphology, morphometry, chromosomal integrity and DNA damage. Results showed significant reduction in ROS production and peroxidation and significant increase in both enzymic and non-enzymic antioxidants in all concentration treated groups when compared with control. Results from all the drug treated groups showed good sperm morphology, increased sperm count and motility. There was no DNA damage and showed normal chromosomal integrity even in 250 mg/kg dose. When compared with control all the three extract treated groups showed increased ROS scavenging activity. However, group II (200 mg/kg) showed significant changes in all the parameters. From the present study it was confirmed that the M. pruriens has potential to improve the sperm qualitatively and quantitatively through scavenging the excess ROS with any adverse side effects. These observations suggest that ethanolic seed extract of M. pruriens may serve as anti-oxidant that can exploit to treat the oxidative stress mediated male factor infertility.

• 환경생물
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• 제29권1호
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• pp.68-73
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• 2011

E. fetida를 방사선과 수은에 각각 노출시킨 후, 체강세포를 추출하고 단세포 겔 전기영동 기법을 이용하여 DNA의 손상정도와 시간의 경과에 따른 수복 양상을 평가해 보았다. 그 결과, 방사선 조사 후의 시간이 경과할수록 대체로 DNA 손상정도가 감소했으며, 12시간 내에 모든 실험군의 DNA가 완전히 수복되었다. 정확한 수복 완료 시간을 알아보기 위해 OTM 값을 대조군과 비교해 보면 2.5와 5Gy는 방사선 조사 후 약 2시간, 10과 20 Gy는 약 3시간, 50 Gy는 약 12시간이 지나자 DNA가 완전히 회복된다고 판단할 수 있었다. 또한 지렁이를 80과 160 mg $kg^{-1}$ 농도의 염화수은(II)에 48시간 동안 노출시킨 후, 수은에 오염되지 않은 깨끗한 배양토에서 72시간을 다시 배양했을 때 손상된 DNA가 완전히 수복되었다. 본 연구 결과는 산화적 스트레스 인자에 대한 생물의 민감도를 측정하는 자료로 제시될 수 있으며, 향후 다양한 생물을 대상으로 실험을 진행한다면 동일한 유전독성 물질에 대한 생물종 간의 감수성을 비교 분석할수 있을 것이다.

• Clinical and Experimental Pediatrics
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• 제56권12호
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• pp.540-544
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• 2013

Down syndrome, the most common chromosomal abnormality, may be associated with various neurologic complications such as moyamoya syndrome, cervical spinal cord compression due to atlantoaxial subluxation, and basal ganglia damage, as well as epileptic seizures and stroke. Many cases of Down syndrome accompanied by isolated neurologic manifestations have been reported in children; however, Down syndrome with multiple neurologic conditions is rare. Here, we have reported a case of Down syndrome in a 10-year-old girl who presented with asymptomatic moyamoya syndrome, atlantoaxial subluxation with spinal cord compression, and basal ganglia calcification. To the best of our knowledge, this is the first report of Down syndrome, in a child, which was accompanied by these 3 neurologic complications simultaneously. As seen in this case, patients with Down syndrome may have neurologic conditions without any obvious neurologic symptoms; hence, patients with Down syndrome should be carefully examined for the presence of neurologic conditions.

• Journal of Nutrition and Health
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• 제10권2호
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• pp.5-11
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• 1977

The mature human braun contains over 10 billion nerve cells (neurons), whose functions are directly related to the acquisition, transfer, processing, analysis, and utilization of all the information. There are also billions of glial cells, which serve primarily to support and to maintain the integrity of the neuron network and to synthesize an essential fatty strucfure, myelin. In the human brain DNA content therefore cell number rises rapidly until birth and then more slowly until $5{\sim}6$ months of age, when it reaches a maximum. While glial cells may be replaced, the more important nerve cell neurons can never be replaced once they are formed. Humans are born with their full complement of neurons and every neuron is as old as each individual. Thus prenatal malnutrition can seriously affect a person's entire life by severely inhibiting the production of neurons before birth.It has been demonstrated that in humans severe malnutrition during the fetal period and in infancy is associated with intellectual impairment. Severely malnourished children have brains smaller than average size and have been found to have $15{\sim}20%$ fewer brain cells than wellnourished childen. There is growing body of literature pointing to malnutrition as a cause of abnormal behavior as evidence that suggests these abnormalities may produce chromosomal damage that may persist forever. Although cognitive development in children is affected by multiple environmental factors, nutrition certainly deaerves more attention than it has received.

• 한국환경성돌연변이발암원학회지
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• 제22권2호
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• pp.90-96
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• 2002

Benzene is a widespread human carcinogen, inducing leukemia and hematotoxicity. Exposure to benzene metabolites has been shown to cause genetic damage, including aneusomy and chromosome aberrations. Fluorescence in situ hybridization(FISH) procedure was used to determine if the benzene metabolite, 1, 2, 4-benzenetriol(BT), hydroquinone(HQ) and trans, trans-muconic acid(t,t-MA) induced specific chromosomal change in HL-60 cells. Treatment with BT, HQ and t,t-MA resulted in the induction of monosomy 8 and 21 in HL-60 cells in a dose-dependent manner. All of these metabolites also induced trisomy 8 and 21, but no correlation between frequencies of trisomy and concentration was found. Translocations between chromosome 8 and another unidentified chromosome ［t(8:\ulcorner)］, and between chromosome 21 and another unidentified chromosome ［t(8:21)］ were found. However, translocation between chromosome 8 and 21 ［t(8:21)］ was not found. Results indicate that the benzene metabolites, BT, HQ and t,t-MA, induce chromosome specific numerical and structural aberrations, and the fluorescence in situ hybridization (FISH) approach may be a useful and powerful technique for detection of aneuploidy.

• Journal of Radiation Protection and Research
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• 제25권4호
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• pp.223-232
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• 2000

단세포전기영동법은 저선량 방사선에 의한 DNA손상을 민감하게 측정할 수 있는 방법으로 그 활용성이 증대되고 있다. 또한 각 염색체에 특이한 DNA probe를 이용하는 FISH기법은 염색체의 구조적 변화를 측정하는 매우 효과적인 방법으로서 그 유용성이 증대되고 있는 추세이다. 본 연구에서는 저선량 방사선의 측정을 위한 생물학적 선량계로서 FISH 기법과 단세포전기영동법의 활용가능성을 조사하고자 하였다. 5, 10, 30, 및 50 cGy의 저선량 방사선 조사에 의한 염색체이상빈도는 상호전좌의 경우 1, 2, 4번 염색체가 전체 genome상에서 차지하는 비율을 감안하여, 전체 세포수로 환산했을 때 cell equivalent당 0.0375, 0.0407, 0.0727 및 0.0814로 나타났으며, 이동원염색체의 경우 0.0125, 0.0174, 0.02291, 및 0.0407로 나타나 선량 증가에 따라 증가하는 것을 알 수 있었다. 또한 $5{\sim}50cGy$의 저선량 방사선 조사 후 단세포전기영동법을 통해 DNA 상해정도를 살펴본 결과 선량이 증가할수록 DNA 상해가 증가하는 결과를 얻었다. 따라서 FISH 기법은 저선량 방사선 피폭시 염색체이상을 보다 정확하고 쉽게 관찰할 수 있으며, 단세포전기영동법은 DNA 손상을 민감하게 감지할 수 있어 저선략 방사선 피폭 시 유용한 생물학적 선량계로서 활용될 수 있을 것으로 기대된다.

• 대한핵의학회지
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• 제33권1호
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• pp.94-99
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• 1999

목적: 조사선량별로 인체 말초혈액 림프구에서 염색체 손상은 중기염색체 분석법으로, 그리고 세포고사는 annexin V를 이용한 유세포계측법으로 정량화하여 서로 비교해 봄으로써, 인체 말초혈액 림프구가 조사선량에 따라 세포사망에 이르는 과정을 밝혀보고자 하였다. 대상 및 방법: 염색체 이상을 동반하는 질환이 없는 건강한 자원자 10명(남자 6명, 여자 4명, 연령범위 $23{\sim}41세$)을 대상으로 하였으며, 이들로부터 혈액을 채혈하여 실험에 이용하였다. 채혈한 혈액으로부터 림프구를 분리하여 0.18, 2, 5, 10, 20. 25 Gy를 조사하였으며, 방사선을 조사하지 않은 림프구를 대조군으로 하였다. 방사선에 조사된 실험군과 대조군을 각각 중기염색체 분석법과 유세포계측법으로 검사하였으며, 중기염색체 분석법에서는 600개의 림프구로부터 불안정 염색체인 2중심염색체와 반지모양 염색체의 수를 계수하였고, 유세포 계측법에서는 세포막의 변화는 annexin V에 결합된 FITC의 섭취로, 그리고 세포핵의 변화는 PI의 섭취로 보았다. 실험군 간의 차이는 ANOVA 검사로, 그리고 두 검사법간의 상관관계는 Pearson의 상관검사로 알아보았다. 결과: 방사선을 조사하지 않은 세포군에서도 불안정 염색체가 $0.5{\pm}0.53$개 관찰되었으며, 실험군에서는 조사선량의 증가에 따라 불안정 염색체의 숫자가 유의하게 증가되었다(p<0.001). 조사선량의 증가에 따라 초기 세포고사는 증가하다가 다시 감소하는 양상을 보이나, 후기 세포고사는 조사선량에 따라 증가하는 양상을 보였다. 중기염색체 분석에서 보이는 불안정 염색체의 수와 Ydr, Qdr 값은 초기 세포고사와는 유의한 상관관계를 보이지 않고, 후기 세포고사와는 매우 유의한 상관관계를 보이고 있었다(p<0.01). 결론: 조사선량에 따른 불안정 염색체의 증가는 유세포계측법으로 검사한 세포핵의 변화와 밀접한 상관관계를 가지고 있었다. 반면 세포막의 변화는 염색체 손상과 관계가 없었으며, 조사선량의 증가에 비례하여 증가하지도 않았다.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1994년도 교수 연수회(환경)
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• pp.681-691
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• 1994

The American Conference of Governmental Industrial Hygienists (ACGIH) has proposed a threshold limit value (TLV) for benzene of 0.1 ppm. Individuals representing the American Petroleum Institute (API)and the Chemical Manufacturers Association (CMA) have argued that 1) the risk assessment by Rinsky .et al. which ACGIH partially relied upon for its proposed TLV overestimates the risk; however, at the exposures levels of interest - (e.g., 0.1 to 1.0 ppm) for establishing a benzene TLV, the Rinsky et al. assessment provides lower estimates of leukemia risk than most others; 2) ACGIH should not use the Dow study for direct observational evidence of leukemia risk associated with low-level benzene exposure because of confounding exposure; however, it is unlikely that confounding exposures played a role in the excess of leukemia demonstrated in the study, and the Dow cohort was exposed to an average benzene concentration of about 5.5 ppm benzene for 7.11 years (31:1.5 ppm-years), while some of the individuals in the study who died from leukemia were exposed to an average of only 1.0 ppm without the opportunity for highpeak exposures; 3) the Occupational Safety and Health Administration (OSHA) established an 8-hour time-weighted average (TWA) of 1.0 ppm in 1987, and there is no new evidence that would justify reducing the TWA below that level; however, the OSHA TWA of 1.0 ppm was based on economic feasibility and the level of excess risk remaining at 1.0 ppm, i.e., 10 excess leukemia deaths per 1000 workers over an occupational lifetime (45 years) according to OSHA's preferred estimate leaves behind I risk considered significant by OSHA. In addition, chromosomal studies among workers and in animals exposed to benzene indicate that low-level exposure, i.e., 1.0 ppm, is associated with elevated Cytogenetic damage. On the basis of adverse health effects data alone, in this author's opinion, it would be poor science and poor public health policy to establish a benzene TLV greater than 0.1 ppm.

• 환경생물
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• 제22권4호
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• pp.507-512
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• 2004

This study was focused on the risk assessment of whether radiofrequency electromagnetic fields generated by mobile phone is cytogenetically toxic or not. We conducted the effects of 835-MHz electromagnetic field (EMF) on DNA strand breaks in mouse thymic lymphoma L5178Y $Tk^{+/1-}$ cells using alkaline comet assay. EMF frequency 835-MHz we chosen is one of the most popular communication frequency bands in Korean code-division multiple-access (CDMA) mobile phone system. The cells were exposed to 835-MHz EMF alone or 835-MHz EMF combined with cyclophosamide(CPA) or 4-nitroquinoline-1-oxide (4NQO) at specific absorption rate (SAR) of 4.0 W $kg^{-l}$ for 24 and 48hrs. DNA damage expressed as tail moment was increased more than two-fold after exposure to 835-MHz EMF for 24 and 48hr. In particular, CPA for 48hr and 4NQO for 24 hr enhanced notably the tail moment to 9-fold and 16-fold in the presence of 835-MHz EMF, respectively, compared to each single treatment. From these results, it appears that exposure to CDMA-mobile phone radiation at 835-MHz frequency may potentiate DNA strand breaks of mouse thymic lymphoma L5178Y $Tk^{+/1-}$;cells under the defined conditions of this study.