• 제목/요약/키워드: Multiple-dose

검색결과 487건 처리시간 0.024초

정상 및 손상된 흰쥐 피부에 국소 적용된 $^{125}I-rhEGF$의 체내 이행 (Body Distribution of $^{125}I-rhEGF$ Across Normal and Damaged Rat Skins)

  • 이정욱;정석재;이민화;심창구
    • 약학회지
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    • 제41권6호
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    • pp.730-736
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    • 1997
  • Distribution of radioactivity in the skin tissues, subcutaneous tissues, blood and body organs was examined following topical application of $^{125}I-rhEGF$(0.4 ${\mu}Ci$), in the form of a Pluronic F-127 gel, on the normal and damaged (burned and stripped) skins of SD male rats. The radioactivity in the skin tissues and subcutaneous tissues was 3-5 times higher for the damaged skins than for the normal skin. But pretreatment of the skin with rhEGF (1${\mu}g$)) twice at 24 hr dose intervals affected the distribution of the radioactivity yielding the order of burned skin> stripped skin=normal skin. The decrease for the stripped skin by the pretreatment might be related either to the pathophysiological change of the skin or to the down regulation of the EGF receptor. Liver showed the highest radioactivity in amount following single and multiple administration of the drug to the normal and damaged skins. But,in concentration, the kidney and stomach showed higher value than the liver which is consistent with that kidney is a major eliminating organ of EGF and that EGF exerts its pharmacological effect specifically for the stomach.

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Successful engraftment after infusion of multiple low doses of CD34+ cells from a poorly matched sibling donor in a patient with severe aplastic anemia

  • Kum, Chang Dae;Lee, Mi Jin;Park, Jun Eun
    • Journal of Yeungnam Medical Science
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    • 제36권2호
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    • pp.148-151
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    • 2019
  • The dose of CD34+ cells is known to influence the outcome of allogeneic peripheral blood stem cell (PBSC) and/or T-cell-depleted transplantation. A previous study proposed that $2{\times}10^6\;CD34+\;cells/kg$ is the ideal minimum dose for allogeneic transplantation, although lower doses did not preclude successful therapy. In the case we present here, CD34+ cells were collected from a matched sibling donor on the day of allogeneic hematopoietic stem cell transplantation; however, the number of cells was not sufficient for transplantation. Consequently, PBSCs were collected three additional times and were infused along with cord blood cells from the donor that were cryopreserved at birth. The cumulative dose of total nuclear cells and CD34+ cells was $15.9{\times}10^8\;cells/kg$ and $0.95{\times}10^6\;cells/kg$, respectively. White blood cells from this patient were engrafted on day 12. In summary, we report successful engraftment after infusion of multiple low doses of CD34+ cells in a patient with severe aplastic anemia.

몬테카를로 코드를 이용한 고에너지 전자가속기의 중성자 skyshine 평가방법 개발 (Development of Neutron Skyshine Evaluation Method for High Energy Electron Accelerator Using Monte Carlo Code)

  • 오주희;정남석;이희석;고승국
    • Journal of Radiation Protection and Research
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    • 제38권1호
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    • pp.22-28
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    • 2013
  • Skyshine은 고에너지 가속기의 차폐 설계 시 반드시 고려되는 중요한 현상이다. 본 연구에서는 고에너지 전자 가속기에 대한 중성자 skyshine 평가 방법을 새롭게 제시하였으며 기존의 방법들과 비교하여 타당성을 검증하였다. 고에너지 전자가속기로부터 원거리 지역의 방사선량을 계산하기 위해 몬테카를로 코드, FLUKA와 PHITS를 이용하였다. 가속기 건물로부터 원거리 지역까지 도달하는 방사선장의 경로를 skyshine, direct, groundshine, multiple-shine으로 분류하였다. 분류된 각각의 성분이 총 유효선량에 기여하는 정도를 평가하였다. 방사선원 계산에는 10 GeV 전자가 두꺼운 표적에 입사하여 생성되는 중성자를 고려하였다. Groundshine 효과를 평가하기위해 PAL-XFEL의 건설부지토양에 대한 성분을 고려하였다. 가속기 건물로부터 비교적 가까운 50 m 미만에서는 direct와 groundshine 성분들이 총 유효선량에 대부분 기여하였다. 가속기 터널로부터 거리가 멀어질수록 skyshine 성분의 기여도가 증가하였다. 평가된 skyshine 성분에 대한 유효선량은 기존에 skyshine 선량을 계산할 때 사용되었던 반실험식 중 전자가속기를 이용한 실험결과에 기반한 Rindi의 식과 가장 잘 일치하였다. 간이계산코드 SHINE3의 결과와 20% 이내로 일치하였다. 모든 성분이 포함된 총 유효선량은 기존의 평가방식에 비해 10배 정도 크게 평가되었다. 가속기 터널로부터 원거리 지역에 대한 선량평가계산에서 mutiple-shine 성분의 영향은 skyshine 성분보다 더 크다는 것을 확인하였다.

두경부(Head & Neck) CT 검사 시 장기의 유효선량 측정 (Effective Dose Determination From CT Head & Neck Region)

  • 윤재혁;이광원;조영기;최지원;이준일
    • 대한방사선기술학회지:방사선기술과학
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    • 제34권2호
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    • pp.105-116
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    • 2011
  • 두경부(Head & Neck) CT(Computed Tomography)검사에서 환자가 받는 피폭선량 측정을 위하여 인체등가물질로 만든 Rando phantom과 유리선량계를 이용하여 두경부 검사에 따른 환자의 흡수선량의 변화를 실험을 통하여 연구하였다. 인체두부모형을 안와신경(optic nerve), 교뇌(pons), 소뇌(cerebellum), 갑상선(thyroid)으로 나누어, 두경부(Head & Neck) 부위의 검사를 단독검사(Brain, 3D Facial, Temporal, Brain Angiography, 3D Cervical Spine)와 복합검사(Brain+Brain Angiography, Brain+3D Facial, Brain+Temporal, Brain+3D Cervical spine, Brain+3D Facial+Temporal, Brain+3D Cervical Spin+Angiography)로 구분하여 유효선량의 변화를 실험한 후 결과를 측정하였다. 단순 Brain검사와 Brain Angio검사에는 optic nerve에 유효 선량이 높게 분석되었으며, 또한 Temporal검사에는 Pons에, 3D facial 검사와 3D Cervical Spin검사에는 thyroid의 유효선량 값이 높게 나타났다. 복합적으로 이루어는 검사 중 두경부의 Brain+Brain Angio의 검사는 cerebellum의 부위, Brain+3D facial 검사와 Brain+3D Cervical Spin의 복합검사는 thyroid의 부위, Brain+Temporal의 검사에는 pon's 부위 유효 선량 값이 높게 나타났다. Brain +3D facial +Temporal의 복합검사와 Brain+3D Cervical Spin+Angio의 복합검사는 thyroid의 부위에 유효 선량 값이 높게 분석 되었다. 본 연구 결과 Brain+3D Cervical Spin+Brain Angio 복합검사인 경우의 유효 선량은 2.51858 mSv로 일반인의 연간 유효선량한도 1 mSv의 피폭을 초과하는 결과가 나왔다. 또한, Brain 단순 검사 시 optic nerve는 0.31312 mSv의 유효선량으로 향후 방사선학 검사가 이루어질 경우, 두경부의 일반인의 연간 유효선량을 훨씬 초과할 것이라 사료된다. 따라서 진료의 필요성에 의해서 시행되는 CT검사일지라도 질환 병변의 특성에 맞게 CT촬영조건 변화를 주면서 환자의 피폭선량을 최소한으로 할 수 있는 다양한 검사방법의 연구가 필요하다고 사료된다.

Feasibility of normal tissue dose reduction in radiotherapy using low strength magnetic field

  • Jung, Nuri Hyun;Shin, Youngseob;Jung, In-Hye;Kwak, Jungwon
    • Radiation Oncology Journal
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    • 제33권3호
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    • pp.226-232
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    • 2015
  • Purpose: Toxicity of mucosa is one of the major concerns of radiotherapy (RT), when a target tumor is located near a mucosal lined organ. Energy of photon RT is transferred primarily by secondary electrons. If these secondary electrons could be removed in an internal cavity of mucosal lined organ, the mucosa will be spared without compromising the target tumor dose. The purpose of this study was to present a RT dose reduction in near target inner-surface (NTIS) of internal cavity, using Lorentz force of magnetic field. Materials and Methods: Tissue equivalent phantoms, composed with a cylinder shaped internal cavity, and adjacent a target tumor part, were developed. The phantoms were irradiated using 6 MV photon beam, with or without 0.3 T of perpendicular magnetic field. Two experimental models were developed: single beam model (SBM) to analyze central axis dose distributions and multiple beam model (MBM) to simulate a clinical case of prostate cancer with rectum. RT dose of NTIS of internal cavity and target tumor area (TTA) were measured. Results: With magnetic field applied, bending effect of dose distribution was visualized. The depth dose distribution of SBM showed 28.1% dose reduction of NTIS and little difference in dose of TTA with magnetic field. In MBM, cross-sectional dose of NTIS was reduced by 33.1% with magnetic field, while TTA dose were the same, irrespective of magnetic field. Conclusion: RT dose of mucosal lined organ, located near treatment target, could be modulated by perpendicular magnetic field.

Clinical management of suspected intracranial meningioma in three dogs with pulsed high-dose hydroxyurea

  • Cho, Jae-Geum;Song, Kun-Ho;Seo, Kyoung-Won
    • 대한수의학회지
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    • 제58권2호
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    • pp.103-106
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    • 2018
  • Three aged dogs, all over 15 years old, with multiple seizure events and various neurologic signs such as head turn and ataxia were brought to the referring hospital. Two cases were tentatively diagnosed with intracranial meningioma based on magnetic resonance imaging, and one case was histopathologically confirmed as meningioma at necropsy. All dogs improved after initiation of pulsed high-dose hydroxyurea (HU) treatment. Clinical sign relapses were managed by repeating high-dose HU without obvious side effects. Pulsed high-dose HU can be applied when clinical signs are refractory to the traditionally recommended dosage for intracranial meningioma in dogs.

Brazilin Augments Cellular Immunity in Multiple Low Dose Streptozotocin (MLD-STZ) Induced Type I Diabetic Mice

  • Yang, Kyoung-Mee;Jeon, Sun-Duck;So, Dhong-Soo;Moon, Chang-Kiu
    • Archives of Pharmacal Research
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    • 제23권6호
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    • pp.626-632
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    • 2000
  • Brazilin, an active principle of Caesalprenia sappan, was examined for its immunopotentiating effects in multiple low dose streptozotocin (MLD-STZ) induced type diabetic mice. Brazilin was intraperitoneally administered for 5 consecutive days to MLD-STZ induced type 1 diabetic mice. Delayed type hypersensitivity, Con A-induced proliferation of splenocytes and mixed lymphocyte reaction, which had been decreased in diabetic mice, were significantly recovered by the administration of brazilin. Brazilin increased IL-2 production without affecting suppressor cell activity. Con A-induced and IL-2-induced expression of high affinity IL-2 receptors were also enhanced by brazilin. These results indicate that brazilin augments cellular immune responses, which are suppressed in the MLD-STZ induced type I diabetic mice, by increasing IL-2 production and responsiveness of immune cells to IL-2.

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다중 센서들을 이용한 다양한 화재 상황의 위험도 추정 시스템 개발 (Implementation of Fire Risk Estimation System for various Fire Situations using Multiple Sensors)

  • 이광재;이연성
    • 센서학회지
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    • 제25권6호
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    • pp.394-398
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    • 2016
  • In this paper, a fire detection system based on quantitative risk estimation is presented. Multiple sensors are used to build a comprehensive indicator that represents the risk of fire quantitatively. The proposed fire risk estimation method consists of two stages which determines the occurrence of fire and estimates the toxicity of the surveillance area. In the first stage, fire is reliably detected under diverse fire scenarios. The risk of fire is estimated in the second stage. Applying Purser's Fractional Effective Dose (FED) model which quantitates harmfulness of toxic gases, the risk of the surveillance area and evacuation time are calculated. A fire experiment conducted using four different types of combustion materials for the verification of the system resulted in a maximum error rate of 12.5%. By using FED calculation and risk estimation methods, the proposed system can detect various signs of fire faster than conventional systems.

Antidiabetic Effect of Ginseng Radix Alba(GRA) and Mori Folium(MF) on Multiple Low Dose Streptozotocin-induced Diabetic Rats

  • Kim, So-Young;Yoon, Seo-Hyun;Chung, Sung-Hyun
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.264.1-264.1
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    • 2002
  • We studied to compare hypoglycemic effect of GRA and MF in multiple low dose streptozotocin(STZ)-induced diabetic rats. 25 mg/kg of STZ in 100 mM citrate buffer(pH 4.5) was injected intraperitoneally for 5 consecutive days. SD rats were randomly divided into diabetic control and treatment groups. Treatment groups were administered with either 500mg/kg of GRA. 500mg/kg of MF. 250mg/kg of GRA+250mg/kg of MF(GM 250)or 500mg/kg of GRA+500mg/kg of MF(GM 500) for 3 weeks. (omitted)

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코발트-60 선원 대체용 고선량률 Ir-192 선원의 조직선량특성 (Characteristics of Tissue Dose of High Dose Rate Ir-192 Source Substitution for Co-60 Brachytherapy Source)

  • 최태진;이호준;김옥배
    • 한국의학물리학회지:의학물리
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    • 제9권4호
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    • pp.259-266
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    • 1998
  • 코발트-60 근접조사선원을 대체할 Ir-l92 선원주변의 2차원적 선량분포를 얻기 위하여, 조사선량률과, 조직감쇠계수를 구하였다. 조직감쇠계수는 선원에서 20 cm 지점까지 실험식을 구하였다. ?보기 방사능은 조사선량상수를 사용하여 결정하였으며, 2.5mm 직경에 두께 2.5 mm 의 선원은 조직선량을 정하기 위해 선원을 4401 개로 분할하여 선원 자체의 흡수효과와 ?슐벽의 차폐 효과와 조직감쇠계수를 적용하였다. 조직감쇠계수는 4차식을 사용하여 1% 오차범위내에서 실험값을 얻을 수 있었으며, Meisberger 상수는 선원에서 많이 떨어질수록 오차가 커서, 10 cm 위치서 7%, 20 cm 에서 33%의 오차를 발견할 수 있었으나, 겉보기방사능과 선원모양 및 크기가 달라 다른 결과를 가져올 수 있다고 본다. 발표된 Ir-192 선원의 에너지스펙트럼을 이용한 선량률상수는 절삭에너지 10 keV인 경우 4.69 R$cm^2$/mCi-hr을 얻었으며 Air Kerma는 0.973 을 구하였다. 이 실험에서 고안 선원의 분할선원에 의한 선원자체흡수와 ?슐벽에 의한 감쇠는 실선원의 54.6%가 겉보기방사능으로 나타남을 알 수 있었으며, 선량계획에 이용하기 위해 단위 ?보기 방사능에 대한 2차원적 선량표를 준비함으로써 기하학적선량과 선량 비등방성을 쉽게 이용할 수 있도록 하였다.

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