• Title, Summary, Keyword: 생물학적 선량측정

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Cytokinesis-blocked micronuclei in the human peripheral lymphocytes following low dose γ-rays irradiation (저선량의 감마선 피폭된 사람 말초 임파구의 미소핵을 이용한 방사선 생물학적 피폭선량 측정법 연구)

  • Kim, Tae-hwan
    • Korean Journal of Veterinary Research
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    • v.41 no.1
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    • pp.99-104
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    • 2001
  • To determine if micronucleus (MN) assay could be used to predict the absorbed dose of victims after accidental radiation exposure, we carried out to assess the absorbed dose depending on the numerical changes of MN in human peripheral blood lymphocytes after $^{60}Co\;{\gamma}-rays$ exposure in the range of 0.25 to 1 Gy, respectively. The MNs were observed at very low doses, and the numerical changes according to doses. Satisfactory dose-effect calibration curve is observed after low dose irradiation of human lymphocytes in vitro. When plotting on a linear scale against radiation dose, the line of best fit was $Y=(0.02{\pm}0.0009)+(0.033{\pm}0.010)D+(0.012{\pm}0.012)D^2$. The dose-response curve for MN induction immediately after irradiation was linear-quadratic and has a significant relationship between the frequencies of MN and dose. These data show a trend towards increase of the numbers of MN with increasing dose. The number of MN in lymphocytes that were observed in the control group is $0.1610{\pm}0.0093/cell$. Accordingly, MN assay in human peripheral lymphocytes could be a useful in viva model for studying radio-protective drug sensitivity or screening test, microdosimertic indicator and radiation-induced target organ injury. Since MN assay is simple, rapid and reproducible, it will also be a biodosimetric indicator for individual dose assessment after accidental exposure.

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The cytokinesis-block micronucleus assay as a biological dosimeter in irradiated lymphocyte : Comparison of the response of mouse and human (임파구의 미세핵 분석법을 이용한 생물학적 방사선 피폭선량 측정 : 마우스와 인체에서의 반응비교)

  • Kim, Sung-ho;Cho, Chul-koo;Kim, Tae-hwan;Yoo, Seong-yul;Koh, Kyoung-hwan;Yun, Hyong-geun;Koh, Joo-hwan;Choi, Soo-yong
    • Korean Journal of Veterinary Research
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    • v.33 no.3
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    • pp.487-492
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    • 1993
  • 정상인 말초혈액임파구 및 C57BL/6마우스 비장임파구에 $^{60}Co{\gamma}-rays$를 in vitro상태에서 조사한 후 500개 또는 1000개의 cytokinesis-blocked(CB) lymphocytes의 미세핵(micronuclei)의 발생빈도를 측정하였다. 방사선조사량에 따라 미세핵의 발생빈도는 증가하였으며 linear-quadratic model로 측정한 결과 선량반응곡선의 식은 인체의 경우 $Y=(0.31{\pm}0.049)D+(0.0022{\pm}0.0002)D^2+13.19$($r^2=1.000$)이었으며, 마우스의 경우 $Y=(1.31{\pm}0.264)D+(0.0015{\pm}0.0006)+8.7$($r^2=0.988$)이었다(Y는 1000개의 CB cell 당 미세핵발생빈도, D는 cGy로 표시되는 조사선량). 인체 말초혈액임파구에 대한 마우스 비장임파구의 상대적 생물학적 효과(relative biological effectiveness)는 미세핵의 발생율이 세포당 0.05~0.8의 범위에서 $1.84{\pm}0.48$이었다. 미세핵분석법은 인체 및 동물의 방사선 피폭시 간편하고 빠른 생물학적 선량측정법으로 사용될 수 있을 것이다.

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The BIDAS Program : Bioassay Data Analysis Software for Evaluating Radionuclide Intake and Dose (BIDAS프로그램 : 방사성 핵종의 섭취량과 선량 평가용 생물학적분석 자료 해석 소프트웨어 프로그램)

  • Tae-Yong Lee;Jong-Kyung Kim;Jong-Il Lee;Si-Young Chang
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.2
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    • pp.113-124
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    • 2004
  • A computer software program, called BIDAS (BIoassay Data Analysis Software) is developed to interpret the bioassay measurement data in terms of intakes and the committed effective dose using the human respiratory tract model (HRTM), gastrointestinal tract (GI-tract) model and biokinetic models currently recommended by the International Commission on Radiological Protection (ICRP) to describe the behavior of the radioactive materials within the body. The program consists of three modules; first, a database module to manage the bioassay data, second, another databasee module to store the predicted bioassay quantities of each radionuclide and finally, a computational module to estimate the intake and committed effective dose calculated with the bioassay quantity measurement values from either an acute or chronic exposure of the radionuclies within the body. This paper describes the features of the program as well as the quality assurance check results of the BIDAS software program.

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Mouse model system based on apoptosis induction to crypt cells after exposure to ionizing radiation (방사선에 전신 조사된 마우스 음와 세포의 아포토시스 유도를 이용한 생물학적 선량 측정 모델 개발 연구)

  • Kim, Tae-Hwan
    • Korean Journal of Veterinary Research
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    • v.41 no.4
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    • pp.571-578
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    • 2001
  • To evaluate if the apoptotic fragment assay could be used to estimate the dose prediction after radiation exposure, we examined apoptotic mouse crypt cells per 1,000 cells after whole body $^{60}Co$ $\gamma$-rays and 50MeV ($p{\rightarrow}Be^+$) cyclotron fast neutron irradiation in the range of 0.25 to 1 Gy, respectively. The incidence of apoptotic cell death rose steeply at very low doses up to 1 Gy, and radiation at all doses tigger rapid changes in crypt cells in stem cell region. These data suggest that apoptosis may play an important role in homeostasis of damaged radiosensitive target organ by removing damaged cells. The curve of dose-effect relationship for the data of apoptotic fragments was obtained by the linear-quadratic model $y=0.18+(9.728{\pm}0.887)D+(-4.727{\pm}1.033)D^2$ ($r^2=0.984$) after $\gamma$-rays irradiation, while $y=0.18+(5.125{\pm}0.601)D+(-2.652{\pm}0.7000)D^2$ ($r^2=0.970$) after neutrons in mice. The dose-response curves were linear-quadratic, and a significant dose-response relationship was found between the frequency of apoptotic cell and dose. These data show a trend towards increase of the numbers of apoptotic crypt cells with increasing dose. Both the time course and the radiation dose-response curve for high and low linear energy transfer (LET) radiation modalities were similar. The relative biological effectiveness (RBE) value for crypt cells was 2.072. In addition, there were significant peaks on apoptosis induction at 4 and 6h after irradiation, and the morpholoigcal findings of the irradiated groups were typical apoptotic fragments in crypt cells that were hardly observed in the control group. Thus, apoptosis in crypt cells could be a useful in vivo model for studying radio-protective drug sensitivity or screening test, microdosimetric indicator and radiation-induced target organ injury. Since the apoptotic fragment assay is simple, rapid and reproducible in the range of 0.25 to 1 Gy, it will also be a good tool for evaluating the dose response of radiation-induced organ damage in vivo and provide a potentially valuable biodosimetry for the early dose prediction after accidental exposure.

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Assessment of DNA damage and Chromosome aberration in human lymphocyte exposed to low dose radiation detected by FISH(fluorescence in situ hybridization) and SCGE(single cell gel electrophoresis) (FISH기법 및 단세포전기영동기법을 이용한 저선량 방사선에 의한 DNA 상해 및 염색체이상 평가)

  • Chung, Hai-Won;Kim, Su-Young;Kim, Byung-Mo;Kim, Sun-Jin;Kim, Tae-Hwan;Cho, Chul-Koo;Ha, Sung-Whan
    • Journal of Radiation Protection and Research
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    • v.25 no.4
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    • pp.223-232
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    • 2000
  • Comparative study was performed for the assessment of DNA damage and Chromosomal aberration in human lymphocyte exposed to low dose radiation using fluorescence in situ hybridization(FISH) and single cell gel electrophoresis(SCGE). Chromosomal aberrations in human lymphocytes exposed to radiation at doses of 5, 10, 30 and 50cGy were analysed with whole chromosome-specific probes by human chromosome 1, 2 and 4 according to PAINT system. FISH with chromosome-specific probe has been used to be a valid and rapid method fer detection of chromosome rearrangements induced by low dose radiation. The frequencies of stable translocation per cell equivalents were 0.0116, 0.0375, 0.040f, 0.0727 and 0.0814 for 0, 5, 10, 30 and 50cGy, respectively, and those of dicentric were 0.00, 0.0125, 0.174, 0.0291 and 0.0407 respectively. Radiation induced DNA damage in human lymphocyte in a dose-dependent manner at low doses from 5cGy to 50cGy, which were analysed by single tell gel electrophoresis(SCGE). From above results, FISH seemed to be useful for radiation biodosimetry by which the frequencies of stable aberrations in human lymphocyte can be observed more easily than by conventional method and SCGE also seemed to be sensitive method f9r detecting DNA damage by low dose radiation exposure, so that those methods will improve our technique to perform meaningful biodosimetry for radiation at low doses.

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Frequency of Micronuclei in Lymphocytes Following Gamma and Fast-neutron Irradiations (방사선 조사량에 따른 인체 정상 림파구의 미세핵 발생빈도)

  • Kim Sung-Ho;Cho Chul-Koo;Kim Tae-Hwan;Chung In-Yong;Yoo Seong-Yul;Koh Kyoung-Hwan;Yun Hyong-Geun
    • Radiation Oncology Journal
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    • v.11 no.1
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    • pp.35-42
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    • 1993
  • The dose response of the number of micronuclei in cytokinesis-blocked (CB) lymphocytes after in vitro irradiation with $\gamma$-rays and neutrons in the 5 dose ranges was studied for a heterogeneous population of 4 donors. One thousand binucleated cells were systematically scored for micronuclei. Measurements performed after irradiation showed a dose-dependent increase in micronuclei (MN) frequency in each of the donors studied. The dose-response curves were analyzed by a linear-quadratic model, frequencies per 1000 CB cells were ($0.31{\pm}0.049$)D+($0.0022{\pm}0.0002)D^2+(13.19{\pm}1.854) (r^2=1.000,\;X^2=0.7074,\;p=0.95$) following $\gamma$ irradiation, and ($0.99{\pm}0.528$)\;D+(0.0093{\pm}0.0047)\;D^2+(13.31{\pm}7.309)\;(r^2=0.996,\;X^2=7.6834,\;p=0.11) following neutrons irradiation (D is irradiation dose in cGy). The relative biological effectiveness (RBE) of neutrons compared with $\gamma$-rays was estimated by best fitting linear-quadratic model. In the micronuclei frequency between 0.05 and 0.8 per cell, the RBE of neutrons was $2.37{\pm}0.17$. Since the MN assay is simple and rapid, it may be a good tool for evaluating the $\gamma$-ray and neutron response.

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Comparison the reference ion chamber in using the radioactive check source and field ion chamber for output dose for Co-60 source of remote afterloading system (시험선원을 이용한 기준 전리함의 감도변화와 임상필드전리함의 성능 안정성 비교)

  • 최태진
    • Progress in Medical Physics
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    • v.12 no.2
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    • pp.141-146
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    • 2001
  • It is well known that assurance of the radiation therapy needs for an accuracy of $\pm$ 5 % in the delivery of an absorbed dose to target volume. Therefore, the dose evaluation of brachytherapy source and/or linear accelerate beam must be a stability with accuracy. In an advanced country, they recommended to use the radioactive check source for reference air ionization chamber for a stable response of radiation field chamber. In this experiments, the radioactive source Sr-90 and PR-05 air ionization chamber were used for standard source and reference ion chamber. The response of reference ion chamber showed as an 1.000$\pm$ 0.010 uncertainty for 10 years long and the evaliuation f dose discrepancy of clinical field ion chamber showed as 0.997 $\pm$0.011 in a $^{60}$ Co brachytherapy soruce. In our experiments, we can assuarance the long halflife standard source is reliable to preserve the calibration factor of reference chamber in stability.

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