• 제목/요약/키워드: Radiological Effects

검색결과 588건 처리시간 0.035초

Korean Red Ginseng saponin fraction modulates radiation effects on lipopolysaccharide-stimulated nitric oxide production in RAW264.7 macrophage cells

  • Lee, Young Ji;Han, Jeong Yoon;Lee, Chang Geun;Heo, Kyu;Park, Se Il;Park, Yoo Soo;Kim, Joong Sun;Yang, Kwang Mo;Lee, Ki-Ja;Kim, Tae-Hwan;Rhee, Man Hee;Kim, Sung Dae
    • Journal of Ginseng Research
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    • 제38권3호
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    • pp.208-214
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    • 2014
  • Background: In previous work, we reported that Korean Red Ginseng saponin fraction (RGSF) showed anti-inflammatory activities in vitro and in vivo. Methods: The present study investigated the radioprotective properties of RGSF by examining its effects on ionizing radiation (IR)-enhanced and lipopolysaccharide (LPS)-mediated inflammatory responses in murine macrophage cells. Results: RGSF induced strong downregulation of IR-enhanced and LPS-induced proinflammatory responses such as nitric oxide (NO) production (Inhibitory Concentration $50(IC_{50})=5.1{\pm}0.8{\mu}M$) and interleukin-$1{\beta}$ levels. RGSF was found to exert its radioprotective effects by inhibition of a signaling cascade that activated checkpoint kinase 2enuclear factor-${\kappa}B$. In addition, RGSF strongly inhibited IR-enhanced LPS-induced expression of hemoxyganase-1, implying that the latter may be a potential target of RGSF. Conclusion: Taken together, our data suggest that RGSF can be considered and developed for use as an effective radioprotective agent with minimal adverse effects.

Time-Dependent Effects of Prognostic Factors in Advanced Gastric Cancer Patients

  • Kwon, Jin-Ok;Jin, Sung-Ho;Min, Jae-Seok;Kim, Min-Suk;Lee, Hae-Won;Park, Sunhoo;Yu, Hang-Jong;Bang, Ho-Yoon;Lee, Jong-Inn
    • Journal of Gastric Cancer
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    • 제15권4호
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    • pp.238-245
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    • 2015
  • Purpose: This study aimed to identify time-dependent prognostic factors and demonstrate the time-dependent effects of important prognostic factors in patients with advanced gastric cancer (AGC). Materials and Methods: We retrospectively evaluated 3,653 patients with AGC who underwent curative standard gastrectomy between 1991 and 2005 at the Korea Cancer Center Hospital. Multivariate survival analysis with Cox proportional hazards regression was used in the analysis. A non-proportionality test based on the Schoenfeld residuals (also known as partial residuals) was performed, and scaled Schoenfeld residuals were plotted over time for each covariate. Results: The multivariate analysis revealed that sex, depth of invasion, metastatic lymph node (LN) ratio, tumor size, and chemotherapy were time-dependent covariates violating the proportional hazards assumption. The prognostic effects (i.e., log of hazard ratio [LHR]) of the time-dependent covariates changed over time during follow-up, and the effects generally diminished with low slope (e.g., depth of invasion and tumor size), with gentle slope (e.g., metastatic LN ratio), or with steep slope (e.g., chemotherapy). Meanwhile, the LHR functions of some covariates (e.g., sex) crossed the zero reference line from positive (i.e., bad prognosis) to negative (i.e., good prognosis). Conclusions: The time-dependent effects of the prognostic factors of AGC are clearly demonstrated in this study. We can suggest that time-dependent effects are not an uncommon phenomenon among prognostic factors of AGC.

국제방사선방호위원회와 방사선방호체계 (The ICRP and Its System of Radiological Protection)

  • 조건우
    • 한국환경보건학회지
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    • 제50권1호
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    • pp.1-5
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    • 2024
  • International Commission on Radiological Protection (ICRP) is an independent international organization that advances the science of radiological protection for the public benefit, particularly by providing recommendations and guidance on all aspects of protection against ionizing radiation. The ICRP is a community of more than 380 globally-recognized experts in radiological protection science, policy, and practice from more than 50 countries. As of January 2024, the ICRP is comprised of a Main Commission, the Scientific Secretariat, four Standing Committees, and 30 Task Groups under the four committees. The ICRP has released well over one hundred publications on all aspects of radiological protection. Most address a particular area within radiological protection, but a handful of the publications, the so-called fundamental recommendations, describe the overall system of radiological protection. The system for radiological protection is based on the current understanding of the science of radiation exposure and its effects along with value judgements. The ICRP offers recommendations to regulatory and advisory agencies and provides advice to management and professional staff with responsibilities for radiological protection. Legislation in most countries adheres closely to ICRP recommendations. The International Atomic Energy Agency's (IAEA) International Basic Safety Standards are based heavily on ICRP recommendations. ICRP recommendations form the core of radiological protection standards, legislation, programs, and practice worldwide.

DOSE AND DOSE RATE EFFECTS OF IRRADIATION ON BLOOD COUNT AND CYTOKINE LEVEL IN BALB/c MICE

  • Son, Yeonghoon;Jung, Dong Hyuk;Kim, Sung Dae;Lee, Chang Geun;Yang, Kwangmo;Kim, Joong Sun
    • Journal of Radiation Protection and Research
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    • 제38권4호
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    • pp.179-184
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    • 2013
  • The biological effects of radiation are dependent on the dose rate and dose of radiation. In this study, effects of dose and dose rate using whole body radiation on plasma cytokines and blood count from male BALB/c mice were evaluated. We examined the blood and cytokine changes in mice exposed to a low (3.49m Gy $h^{-1}$) and high (2.6 Gy $min^{-1}$) dose rate of radiation at a total dose of 0.5 and 2 Gy, respectively. Blood from mice exposed to radiation were evaluated using cytokine assays and complete blood count. Peripheral lymphocytes and neutrophils decreased in a dose dependent manner following high dose rate radiation. The peripheral lymphocytes population remained unchanged following low dose rate radiation; however, the neutrophils population increased after radiation. The sera from these mice exhibited elevated levels of flt3 ligand and granulocyte-colony-stimulating factor (G-CSF), after high/low dose rate radiation. These results suggest that low-dose-rate radiation does not induce blood damage, which was unlike high-dose-rate radiation treatment; low-dose-rate radiation exposure activated the hematopoiesis through the increase of flt3 ligand and G-CSF.

Protective effects of Ginsan against Cyclophosphamide-induced immunosuppression in mice

  • Shim, Ji-Young;Ahn, Ji-Yeon;Han, Young-Soo;Jung, In-Sung;Yun, Yeon-Sook;Song, Jie-Young
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.206.1-206.1
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    • 2003
  • The immunomodulator Ginsan has been found previously by us to stimulate the secretion of high levels of IL -1. IL -6 and TNF-alpha in irradiated mice. These cytokines are known to induce proliferation and differentiation of hematopoietic progenitor cells from the spleen and bone marrow and to protect mice from DNA-damaging agents. The present studies were evaluated as a cytoprotective agent against toxicity of the alkylating drugs. (omitted)

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