• Title/Summary/Keyword: aberrations

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Diabetes - Increased Risk for Cancers through Chromosomal Aberrations?

  • Anand, Sudhaa;Nath, Badari;Saraswathy, Radha
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4571-4573
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    • 2014
  • Diabetes, a comprehensive genetic disease, is principally due to the deregulation of glucose levels in the blood. In addition to contemporary epidemiological studies, systematic substantiation suggests that long-term diabetes leads to cancers due to a variety of reasons. In this study, blood samples were collected with informed consent from confirmed type I diabetic (T1DM, n=25) and type II Diabetic patients (T2DM, n=25) with equal numbers of controls. Further depending on the lifestyle habits they were subdivided into smokers/non-smokers and alcoholics/non-alcoholics. Chromosomal assays were performed for these cases and it was found that there was a significant increase in chromosomal aberration frequency in diabetic patient groups who are exposed to smoking and alcohol than that of normal diabetic groups (T1DM and T2DM). On the other hand, patient groups who were non-smoking and non-alcoholics also showed higher chromosomal aberrations when compared to that of controls. While the mechanisms for these increased chromosomal aberrations in diabetic groups are not clear, they may be due to increased oxidative stress leading to oxidative damage and resulting in genomic instability, which in turn may contribute to an increased risk for cancer.

The Effects of Inhibitors of DNA Polymerases and Topoisomerase on Chromosome Aberrations Induced by Mutagens in Synchronized Mammalian Cells (동시화된 포유동물 세포에서 돌연변이원에 의해 유발된 염색체 이상에 미치는 DNA중합효소와 DNA위상이성질화효소의 저해제의 효과)

  • 엄경일;신은주;권영순
    • Environmental Mutagens and Carcinogens
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    • v.10 no.2
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    • pp.85-92
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    • 1990
  • The effects of aphidicolin (APC), 2`,3`-dideoxythymidine 5`-triphosphate (ddTTP), and novobiocin (NOV) on the frequencies of chromosome aberrations induced by ethyl methanesulfonate (EMS) or bleomycin (BLM) were examined in synchronized Chinese hamster ovary (CHO)-K$_1$ cells. The cells were synchronized by the thymidine double block method. APC, ddTTP and NOV alone did not affect the frequencies of chromosome aberrations. The cells in late G$_1$ and early S phases were sensitive to the induction of chromosome aberrations by EMS, wherase cells in G$_2$ phase were most sensitive to chromosme aberration by BLM.

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Simulation Research on the Thermal Effects in Dipolar Illuminated Lithography

  • Yao, Changcheng;Gong, Yan
    • Journal of the Optical Society of Korea
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    • v.20 no.2
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    • pp.251-256
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    • 2016
  • The prediction of thermal effects in lithography projection objective plays a significant role in the real-time dynamic compensation of thermal aberrations. For the illuminated lithography projection objective, this paper applies finite element analysis to get the temperature distribution, surface deformation and stress data. To improve the efficiency, a temperature distribution function model is proposed to use for the simulation of thermal aberrations with the help of optical analysis software CODE V. SigFit is approved integrated optomechanical analysis software with the feature of calculating OPD effects due to temperature change, and it is utilized to prove the validation of the temperature distribution function. Results show that the impact of surface deformation and stress is negligible compared with the refractive index change; astigmatisms and 4-foil aberrations dominate in the thermal aberration, about 1.7 λ and 0.45 λ. The system takes about one hour to reach thermal equilibrium and the contrast of the imaging of dense lines get worse as time goes on.

Chromosome Aberrations of Styrene Exposed Workers (스티렌 취급근로자의 염색체이상연구)

  • Maeng, Seung Hee;Kang, Sung Kyu;Yang, Jung Sun;Lee, Jong Sung;Yu, Il Je
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.5 no.1
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    • pp.40-47
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    • 1995
  • We analyzed sytrene concentrations in air and in blood, mandelic acid in urine, and chromosome aberrations in peripheral lymphocytes of twenty one styrene-exposed workers in two reinforced plastic factories. In addition, in vitro testing for chromosome aberration was carried out. The dose-dependent clastogenicity of styrene was confirmed in the cultured Chinese hamster lung cell(CHL) with metabolic activation. The environmental styrene concentrations and urinary mandelic acid levels of analyzed subjects were different in two plants examined, but the exposure levels in most workers examined were lower than the permissible exposure levels. Chromosome aberrations of the styrene exposed workers showed no increase in the percentage of aberrant cells as compared with the control group. No correlation was found between the exposure levels and the frequencies of chromosome aberrations in workers.

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Determination of Corneal Aberrations Using Corneal Shape of Topographer (각막지형검사기의 각막형상을 이용한 각막수차 구현)

  • Park, Seong-Jong;Kim, Sun-Young;Han, Kyung-Soo;Joo, Seok-Hee;Chun, Young-Yun
    • Journal of Korean Ophthalmic Optics Society
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    • v.14 no.2
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    • pp.35-39
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    • 2009
  • Purpose: In this study a program was developed to determine corneal aberrations using corneal shape of topographer and represented a wavefront and corneal aberrations using zernike polynomial. Methods: When the pupil size was 6 mm, we calculated new corneal shape data with zernike polynomials using corneal shape data of ORBSCAN topographer. We programmed the wavefront construction using ray tracing for corneal shape, then represented corneal aberrations having zernike polynomial with 6th order and 28 terms. Conclusions: We developed programs to determine a wavefront and corneal aberrations using corneal shape of ORBSCAN topographer. Theses results will be applied to a development of new topographer and prescription of contact lens and OK lens.

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Studies on the Chemical Nutagen-induced DNA Repair Synthesis in Relation to Chromosome Exchanges (突然變異誘發原에 의한 DNA回復合成과 染色體交換과의 聯關性에 관한 硏究)

  • Park, Sang-Dai;Um, Kyung-Il;Park, Kyung-Hee
    • The Korean Journal of Zoology
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    • v.19 no.4
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    • pp.179-186
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    • 1976
  • DNA repari synthesis and chromosome aberrations induced by various concentrations of alkylating agents (MMS, MNNG, MMC) in cultured human lymphocytes and HeLa $S_3$ cells were studied to determine the possibility of correlation between these two types of biological phenomena, and the results obtained were as follows: DNA repair synthesis was detected in MMC, MNNG and MMS treated HeLa $S_3$ cells at the concentrations of $3 \\times 10^{-7}M, 1 \\times 10^{-6}M, 5 \\times 10^{-4}M$, respectively. These results indicate that MMC is the most potent mutagen followed by MNNG, and MMS is the least potent among these three types of alkylating agents. MMC and MNNG did not show any significant increases of DNA repair synthesis as dose increased, while MMS did. Chromosome aberrations induced by MMC in human lymphocytes was increased as dose increased, but not chromosome exchanges. MNNG did not induce any significant amount of chromosome aberrations with doses, and exchanges were not observed in MNNG treated cells. MMS, however, induced both chromosome aberrations and exchanges, and their rates were increased as dose increased. These results suggest that DNA repair synthesis induced by these alklating agents may not be directly related to the production of chromosome aberrations and exchanges.

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Corneal Asphericity and Optical Performance after Myopic Laser Refractive Surgery (굴절교정수술을 받은 근시안의 각막 비구면도와 광학적 특성 평가)

  • Kim, Jeong-Mee;Lee, A-Young;Lee, Koon-Ja
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.2
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    • pp.179-186
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    • 2013
  • Purpose: To compare corneal asphericity, visual acuity (VA), and ocular and corneal higher-order aberrations (HOAs) between myopic refractive surgery and emmetropia groups. Methods: Twenty three subjects ($23.0{\pm}2.5$ years) who underwent myopic refractive surgery and twenty emmetropia ($21.0{\pm}206$ years) were enrolled. The subjects'criteria were best unaided monocular VA of 20/20 or better in both two groups. High and low contrast log MAR visual acuities were measured under photopic and mesopic conditions. Corneal and ocular HOAs were measured using Wavefront Analyzer (KR-1W, Topcon) for 4 mm and 6 mm pupils. Corneal asphericity was taken by topography in KR-1W. Results: There was no significant difference in VA between two groups under either photopic or mesopic conditions. In ocular aberrations, there were significant differences in total HOAs, fourthorder and spherical aberration (SA) for a 6 mm between two groups (p=0.045, p<0.001, and p<0.001, respectively). In corneal aberrations, there was a significant difference in SA for 4 mm (p=0.001) and 6 mm (p<0.001) pupils between two groups and there were statistically significant differences in total HOAs (p<0.001) and fourth-order aberrations (p<0.001) between two groups for a 6 mm pupil. There was a significant correlation in emmetropia between Q-value and SA in ocular aberrations for 4 mm and 6 mm pupils (r=0.442, p=0.004, and r=0.519, p<0.001) and in corneal aberrations for 4 mm and 6 mm pupils (r=0.358, p=0.023, and r=0.646, p<0.001). No significant correlations were found between Q-value and SA in refractive surgery group. Conclusions: VA in myopic refractive surgery is better than or similar to emmetropia. Nevertheless, the more increasing pupil size is, the more increasing aberrations are. Thus, it could have an influence on the quality of vision at night.

Chromosome Aberrations and Sister Chromatid Exchanges in Peripheral Lymphocyte of Nurses Handling Anticancer Drugs (항암제 취급 간호사의 염색분이상 및 자매염색분교환빈도)

  • 김소정;이성은;정해원
    • 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.

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Mechanism of Arsenic-Induced Cytotoxiciht in CHO Cells (CHO 세포에서 비소의 세포독성기전)

  • 정해원;기혜성;박영철;한정호;유일재
    • Environmental Mutagens and Carcinogens
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    • v.16 no.2
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    • pp.117-123
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    • 1996
  • This study was carried out to examine the mechanism of Arsenic cytotoxicity through several in vitro test systems. Dose-dependent decrease of cell survival by Arsenic was observed by colony forming assay. Arsenic was weak mutagenic in inducing HGPRT point mutation in CHO cells. The frequency of chromosomal aberrations increased in a dose-dependent manner and the most frequent type of chromosomal aberrations induced by Arsenic were chromatid type deletions. U!trafiltrates of culture media from CHO cells treated with Arsenic induced sister chromatid exchanges(SCE) in CHO cells and Arsenic was able to induce lipid peroxidation in CHO cells. The results suggested that the ultrafiltrates of media from CHO cells treated with Arsenic contain clastogenic factor(CF) and Iipid peroxidation might be involved in the formation of CF.

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BENZENE INDUCED CHROMOSOME ABERRATIONS AND THE ASSOCIATION WITH GENETIC POLYMORPHISM

  • Kim, Su-Young;Cho, Yoon-Hee;Jung, Eun-Jung;Park, Jung keun;Paek, Do-Myung;Chung, Hai-Won
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2002.05a
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    • pp.66-66
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    • 2002
  • This study was done to examine the benzene induced chromosomal aberrations and also the influence of genetic polymorphism(GSTM1, GSTT1, GSTP1, NAT2, NQO1, CYP2E1 and CYP1A1) on the chromosomal aberrations. In total, 82 benezene exposed workers and 76 matched controls were examined.(omitted)

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