• Title/Summary/Keyword: Biological effectiveness

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Basics of particle therapy II: relative biological effectiveness

  • Choi, Jin-Hyun;Kang, Jin-Oh
    • Radiation Oncology Journal
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    • v.30 no.1
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    • pp.1-13
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    • 2012
  • In the previous review, the physical aspect of heavy particles, with a focus on the carbon beam was introduced. Particle beam therapy has many potential advantages for cancer treatment without increasing severe side effects in normal tissue, these kinds of radiation have different biologic characteristics and have advantages over using conventional photon beam radiation during treatment. The relative biological effectiveness (RBE) is used for many biological, clinical endpoints among different radiation types and is the only convenient way to transfer the clinical experience in radiotherapy with photons to another type of radiation therapy. However, the RBE varies dependent on the energy of the beam, the fractionation, cell types, oxygenation status, and the biological endpoint studied. Thus this review describes the concerns about RBE related to particle beam to increase interests of the Korean radiation oncologists' society.

Estimation of the Biological Effectiveness of Auger Electron-Emitting Radiopharmaceuticals for Targeted Radiotherapy

  • Teresa W. Na;Jung-Young Kim;Kwang Il Kim;Ilsung Cho
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.10 no.1
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    • pp.97-103
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    • 2024
  • Relative biological effectiveness (RBE) plays an important role in relating physical dose to cell-killing biological dose. The calculation of the RBE is an important basic task in realization of radionuclide therapy using 64Cu. In this study, the method of calculating the RBE of emitted particles from 64Cu is presented using Monte Carlo simulation. U-87 MG cell model is designed to perform Monte Carlo simulation. The Geant4 simulation tool kit was used to simulate the secondary particles for transport into media. The specific energy in the cell nucleus and the domain was estimated. The Microdosimetric Kinetic model (MK model) is used to estimate RBE. The method presented in this study may be helpful to estimate biological dose in treatment with 64Cu.

Estimation of Relative Biological Effectiveness for Carbon Beam

  • Onizuka, Y.;Endo, S.;Takada, M.;Ishikawa, M.;Hoshi, M.;Uehara, S.;Hayabuchi, N.;Maeda, N.;Shizuma, K.
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.219-221
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    • 2002
  • In this work, single event spectra were measured in order to gain the microdosimetric parameters of some heavy ion radiotherapy fields at HIMAC. Microdosimetry is now a well-established technique for the investigation of complex mixed radiation field. Changes in frequency mean lineal energy y$\_$F/ as a function of thickness of A150 phantom were obtained. The absorbed dose was obtained by using y$\_$F/. A direct relation between this single event probability distribution and relative biological effectiveness (RBE) was assumed in order to estimate RBE using the response function.

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Review of the Existing Relative Biological Effectiveness Models for Carbon Ion Beam Therapy

  • Kim, Yejin;Kim, Jinsung;Cho, Seungryong
    • Progress in Medical Physics
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    • v.31 no.1
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    • pp.1-7
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    • 2020
  • Hadron therapy, such as carbon and helium ions, is increasingly coming to the fore for the treatment of cancers. Such hadron therapy has several advantages over conventional radiotherapy using photons and electrons physically and clinically. These advantages are due to the different physical and biological characteristics of heavy ions including high linear energy transfer and Bragg peak, which lead to the reduced exit dose, lower normal tissue complication probability and the increased relative biological effectiveness (RBE). Despite the promising prospects on the carbon ion radiation therapy, it is in dispute with which bio-mathematical models to calculate the carbon ion RBE. The two most widely used models are local effect model and microdosimetric kinetic model, which are actively utilized in Europe and Japan respectively. Such selection on the RBE model is a crucial issue in that the dose prescription for planning differs according to the models. In this study, we aim to (i) introduce the concept of RBE, (ii) clarify the determinants of RBE, and (iii) compare the existing RBE models for carbon ion therapy.

Radiation Biology in Space; DNA Damage and Biological Effects of Space Radiation

  • Ohnishi, Takeo;Takahashi, Akihisa;Ohnishi, Ken
    • Journal of Photoscience
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    • v.9 no.3
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    • pp.37-40
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    • 2002
  • Astronauts are constantly exposed to space radiation at a low-dose rate during long-tenn stays in space. Therefore, it is important to determine correctly the biological effects of space radiation on human health. Space radiations contain various kinds of different energy particles, especially high linear energy transfer (LET) particles. Therefore, we have to study the relative biological effectiveness (RBE) of space radiation under microgravity environment which may change RBE from a stress for cells. Furthermore, the research about space radiation might give us useful information about birth and evolution of life on the earth. We also can realize the importance of preventing the ozone layer from depletion by use of exposure equipment to sunlight at International Space Station (ISS).

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Cost Effectiveness of Clozapine and Risperidone in "Revolving Door" Schizophrenia (재발과 입원을 반복하는 만성 정신분열병 환자에서 비전형적 항정신병약물의 비용-효과)

  • Nam, Jong-Won;Lee, Min-Soo;Jeong, In-Kwa;Kwak, Dong-Il
    • Korean Journal of Biological Psychiatry
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    • v.7 no.2
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    • pp.198-205
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    • 2000
  • Objectives : Risperidone and clozapine belong to a new generation of antipsychotics that are reportedly more effective and better tolerated than conventional neuroleptics. However, each of these agents costs far more per unit than conventional neuroleptics. The purpose of our retrospective study was to ascertain the total cost and effectiveness of treatment before and after administration of risperidone and clozapine in "revolving door" schizophrenia patients. Method : Data collected on revolving door schizophrenics for 2 years before clozapine and risperidone treatment and for at least 2 years after clozapine and risperidone treatment. Direct cost of inpatient and outpatient treatment was measured. Effectiveness was scaled as "years of mild disability gained". Result : Both risperidone and cloazpine result in higher costs and additional benefits to patients, for example, increased mild disability, reduced number of relapse, and reduced hospital length-of-stay. An ICER of risperidone was less than Rc and ICER of clozapine was greater than Rc. According to decision-analytic this model, risperidone had favorable cost-effectiveness ratios relative to clozapine. Conclusion : We have assumed that risperidone is more cost-effective than clozapine.

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Service life of concrete culverts repaired with biological sulfate-resisting mortars

  • Hyun-Sub, Yoon;Keun-Hyeok, Yang;Nguyen, Van Tuan;Seung-Jun, Kwon
    • Computers and Concrete
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    • v.30 no.6
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    • pp.409-419
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    • 2022
  • The purpose of this study is to examine the effectiveness of biological repairing mortars on restoring the structural performance of a sewage culvert deteriorated by sulfate attack. The biological mortars were developed for protecting concrete structures exposed to sulfate attack based on the block membrane action of the bacterial glycocalyx. The diffusion coefficient of sulfate ions in the biological mortars was determined from the natural diffusion cell tests. The effect of sulfate-attack-induced concrete deterioration on the structural performance of culverts was examined by using the moment-curvature relationship predicted based on the nonlinear section lamina approach considering the sulfuric-acid-induced degradation of the structure. Typical analytical assessments showed that biological mortars were quite effective in increasing the sulfate-resistant service life of sewage culverts.

Prevention of Murine Acquired Immunodeficiency Syndrome (MAIDS) Development by Oriental Herb Extracts

  • Yang, Yun-Hee;Yang, Joo-Sung
    • Journal of Applied Biological Chemistry
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    • v.48 no.4
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    • pp.170-177
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    • 2005
  • Oriental medicinal herb extracts (OHE) showing anticancer activities were investigated for effectiveness as antiviral drugs. Infection of MuLV to cell line resulted in formation of giant syncytia. Number of giant syncytia in culture treated with OHE decreased by 40% compared to that of non-OHE-treated cell culture. To determine OHE effects on progeny release, RT-PCR was performed. In vivo animal studies demonstrated effectiveness of OHE as antiviral drug when administered orally. After OHE administration, viral cytopathic effects decreased. Infected mice showed splenomegaly and over-proliferation of lymphocytes with decreased CD4+ cell counts. These symptoms decreased in OHE-treated mice, indicating OHE maybe useful therapeutics against MuLV/MAIDS as Human Immunodeficiency Virus (HIV)/AIDS animal model. Results show XC plaque assay and in vivo MAIDS model using MuLV are suitable tools for screening anti-retroviral drug candidates.

Current Pharmacogenetics in Psychiatry (정신의학에서의 약물유전학 현황)

  • Kim, Il Bin;Lee, Yu Sang
    • Korean Journal of Biological Psychiatry
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    • v.28 no.1
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    • pp.1-6
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    • 2021
  • Pharmacogenetics is opening a new era of precision medicine in psychiatry. Drug-metabolizing enzymes are characterized by genetic polymorphisms, which render a large portion of variability in individual drug metabolism. Dose adjustment based on pharmacogenetics knowledge is a first step to translate pharmacogenetics into clinical practice. However, diverse factors including cost-effectiveness should be addressed to provide clinical recommendation. To address current challenges in pharmacogenetics testing in psychiatry, this review provides an update regarding genotyping (SNP analysis, array, and next-generation sequencing), genotype-phenotype correlations, and cost-effectiveness. The current updates on pharmacogenetics in psychiatry will provide guidance for both clinician and researchers to have a consensus in harmonizing efforts to advance the pharmacogenetics field in a part of precision medicine in psychiatry.

The Relative Biological Effectiveness of KCCH-Cyclotron neutron (원자력병원(原子力病院) 싸이클로트론 속중성자선(速中性子線)의 방사선생물학적효과비(RBE)에 관(關)한 연구(硏究))

  • Yoo, Seong-Yul;Koh, Kyoung-Hwan;Cho, Chul-Koo;Kim, Sung-Ho
    • Journal of Radiation Protection and Research
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    • v.12 no.2
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    • pp.1-8
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    • 1987
  • The relative biological effectiveness has been measured for the biological characterization of $p^+(50.5\;MeV)$ Be neutron of KCCH-Cyclotron prior to clinical application. Measured RBE of mouse jejunal crypt cell in single whole body irradiation was 2.8. This RBE value is changed differently in different biologic systems such as mouse jejunal crypt cells, intestine and bone marrow in different irradiation method, so that in fractionated irradiation RBE is variable to the different fraction size and total dose, and also variable to the number of fractions.

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