• Journal of Ginseng Research
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• 제17권2호
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• pp.114-122
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• 1993

0.5 mg of natural ginsenoside mixture and 0.8 $\mu$Ci of synthesized 14C-ginsenosides were administered orally to a rat and killed at one hour after the ginsenoside administration and the liver was fractionated into nuclear fraction, mitrochondria microsomes and cytosol fraction. Radioactivity distribu lion in subcellular fractions of the liver showed that 32o1c of total radioactivity absorbed in the liver was in cytosol fraction but a significant portion of the radioactivity was also found in mitochondria (26.6%) and microsomal fraction (18.l%). 5.8% of the total radioactivity was recovered from the nuclear fraction as well. This suggested that ginsenosides might be distributed into all subcellular fractions. Activities of mitochondrial aldehyde dehydrogenase, lactate dehydrogenase and malate dehydrogenase of the liver of rat at two hours after the ginsenoside administraion were found appreciably stimulated, suggesting that the ginsenoside concentration in the liver might be around 10-5%, since optimum concentrations for most enzyme catalyzed reactions in vitro were known to be 10-6% 10-4%. A significant portion of the radioactivity recovered from subcellular fractions of the liver was found in protein fractions, suggesting that proteins might interact with ginsenosides. Examination of protein-ginsenoside interation by gel filtration, equilibrium dialysis and amonium sulfate precipitation technique suggesting that proteins and ginsenosides do not bound covalently but weakl\ulcorner combined. When purified ginsenoside Rbl and Rgl were incubated with rat liver cytosolic enzymes for 20 min, the above ginsenosides were hydrolyzed quickly, suggesting that ginsenosides might be rapidly hydrolyzed and metabolized in the liver. It was also observed in vitro that the ginsenosides such as Rbl and Rgl were easily hydrolyzed by rat liver cytosol preparation suggesting that absorbed ginsenosides might be quickly hydrolyzed and metabolized in the liver.

• Journal of Periodontal and Implant Science
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• 제48권2호
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• pp.70-83
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• 2018

Purpose: The aim of this study was to evaluate the capacity of single and combined applications of the bark of the stems and roots of Magnolia officinalis Rehd. et Wils. (Magnoliae Cortex) and Zea mays L. (maize) to modulate inflammation in RAW 264.7 cells stimulated with Porphyromonas gingivalis. Methods: RAW 264.7 cells were stimulated with P. gingivalis, and Magnoliae Cortex and/or maize was added. Cytotoxicity and the capacity to modulate inflammation were determined with a methylthiazol tetrazolium (MTT) assay, nitrite production, enzyme-linked immunosorbent assay (ELISA), and western blotting. Results: Treatment with Magnoliae Cortex and/or maize inhibited nuclear transcription factor ${\kappa}B$ ($NF-{\kappa}B$) pathway activation and nuclear p44/42 mitogen-activated protein kinase (MAPK) and inducible nitric oxide synthase (iNOS) protein expression in P. gingivalis-stimulated RAW 264.7 cells. Moreover, the treatments suppressed cytokines (prostaglandin $E_2$ [$PGE_2$], interleukin $[IL]-1{\beta}$, and IL-6) and nitrite production. Conclusions: Both Magnoliae Cortex and maize exerted an anti-inflammatory effect on P. gingivalis-stimulated RAW 264.7 cells, and this effect was more pronounced when the extracts were combined. These findings show that these extracts may be beneficial for slowing the progression of periodontal disease.

• Journal of Radiation Protection and Research
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• 제3권1호
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• pp.6-22
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• 1978

High energy electron beams took effect for tumor radio-therapy, however, had a lot of problems in clinical application because of various conversion factors and complication of physical reactions. Therefor, we had experimentally studied the important properties of high energy electron beams from the linear accelerator, LMR-13, installed in Yonsei Cancer Center. The results of experimental studies on the problems in the 8, 10, 12 Mev electron beam therapy were reported as following. 1. On the measurements of the outputs and absorbed doses, the ionization type dosimeters that had calibrated by $^{90}Sr$ standard source were suitable as under 3% errors for high energy electrons to measure, but measuring doses in small field sizes and the regions of rapid fall off dose with ionization chambers were difficult. 2. The electron energy were measured precisely with energy spectrometer consisted of magnet analyzer and tele-control detector and the practical electron energy was calculated under 5% errors by maximum range of high energy electron beam in the water. 3. The correcting factors of perturbated dose distributions owing to radiation field, energy and material of the treatment cone were checked and described systematically and variation of dose distributions due to inhomogeneous tissues and sloping skin surfaces were completely compensated. 4. The electron beams, using the scatterers; ie., gold, tin, copper, lead, aluminium foils, were adequately diffused and minimizing the bremsstrahlung X-ray induced by the electron energy, irradiation field size and material of scatterers, respectively. 5. Inproving of the dose distribution from the methods of pendulum, slit, grid and focusing irradiations, the therapeutic capacity with limited electron energy could be extended.

• 동의생리병리학회지
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• 제25권3호
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• pp.459-465
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• 2011

The nuclear factor of activated T cells (NFAT) protein induces transcriptions of cytokine genes including IL-2 for T-cell activation. Normally activation of NFAT is important to induce immune responses but excessive NFAT activation provokes immunopathological reactions such as autoimmunity, transplant rejection, and inflammation. Thus, for the treatment of autoimmune diseases drugs repressing the activation of NFAT have been searched. In this study, immnunosuppressive effects of Rosa chinensis Jacq. extracts identified as a potent NFAT inhibitor from a natural product library were examined. NFAT reporter assay, MTS assay, real time PCR, IL-2 ELISA, MLR, and FACS (Fluorescent Activated Cell Sorting) were used to measure inhibitory immunocyte activities of Rosa chinensis Jacq. The variety of natural products have been screened and some were found to show inhibitory activities against the NFAT transcription factor. Among them, extract of Rosa chinensis Jacq. showed an strong inhibitory effect on the activation of NFAT without affecting cell viability. Levels of IL-2 transcripts as well as IL-2 protein were decreased with treatment of Rosa chinensis Jacq. extract. In addition, immunosuppressive activity of Rosa chinensis Jacq. extract was exhibited in the mixed leukocytes reaction. The increasement of CD4+CD25+ (Treg) immunocyte was also detected in the analysis using FACS after applying Rosa chinensis Jacq. extract. Immunosuppressive effects of the Rosa chinensis Jacq. extracts were clearly demonstrated in the present study. In addition, Rosa chinensis Jacq. extract also positively affected regulatory T cell induction. Further investigations in particular on purification of single substance responsible for the immunosuppressive effects from the extract and analysis on possible actions of the extract in interfering cell signaling and cytokine production will be needed.

• Nuclear Engineering and Technology
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• 제2권2호
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• pp.67-72
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• 1970

250kw로 운전중에 있는 TRIGA MARK-II의 중심공에서 threshold deector를 사용하여 고속중성자속과 스펙토륨을 측정하였다. 이 측정에는 다음과 같은 반응을 이용하였다. 즉 Ni$^{58}$ (n,p) Co$^{58}$ ； $Mg^{24}$ (n,p) $Na^{24}$ ； $Al^{27}$ (n, $\alpha$) $Na^{24}$ . 반응에서 측정된 실험결과로부터 반실험적인 방법에 의하여 CDC-3600계산기를 이용하여 고속중성자의 스펙토륨과 중성자속을 계산하였다. 중심공에서는 분열 스펙토륨의 가정이 1 내지 2Mev 이상에서만 타당하다는 것이 밟혀졌다. 이 스펙토륨을 이용하여 2.6Mev 이상의 고속중심자속은 1$\times$$10^{12}$ n/$\textrm{cm}^2$-sec 정도가 됨을 관측하였다.

• Nuclear Engineering and Technology
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• 제20권2호
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• pp.120-131
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• 1988

지중매몰된 방사성핵종들이 지하수계를 통해 이동을 하는 Source를 수학적으로 표시하는 Source Term 모형이 필요하다. 물질전달식 또는 측정식에 근거한 여러 Source Term 모형을 비교 분석하였다. 일반적으로 용출 또는 용해에는 (1) 화학반응, (2) 확산 등에 의한 물질이동의 두 가지 작용이 관여한다. 화학반응은 고화체가 지하수에 노출된 후 초기의 짧은 기간 동안에만 용해율을 조절한다. 외부로의 물질전달율이 지하 처분장에서 방사성폐기물 고화체로부터의 장기간에 걸친 핵종유출율을 조절하는 역할을 한다. 물질전단 이론을 적용 할 때는, 필요로 하는 물질이동 현상을 기술할 수 있는 식을 선택해야 한다. 적절히 사용했을 경우, 물질전달 이론에 입각한 Source Term 모형은 핵종유출율의 신뢰할 만한 예측을 위한 귀중한 도구이다.

• Nuclear Engineering and Technology
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• 제5권3호
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• pp.202-213
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• 1973

본 연구의 제1보에 뒤이어서 방향족 염소유도체외 Szilard Chalmer 반응으로 얻어진 유기충치 성분을 분리하여서 표지 조건을 검토하였다. 여러가지 성분을 모두 분리할 수는 없었으나 주성분을 증류법 및 박층 Chromatography등으로 분리하였으며 그 화학구조가 원시료의 표지물임을 확인하였다. 고체시료의 경우에는 주성분이 유기표지물의 80-60%이였고 액체시료에 있어서는 70% 이하였다. 장시간 조사하면 주성분 수율이 증가되었으나 방사선에 불안정한 화합물의 경우에는 도리어 감소하였다. Chromatography로 분리되는 부생성물들의 수율은 액체시료의 경우 많았으나 고체의 경우는 이 보다 적었고 따라서 주생성물의 분리가 용이하였다. 각 화합물의 표지수율을 표시하고 Chromatography에 의한 분리조건을 논의하였으며 이 표지 방식의 실용성을 화학구조와 관련시켜 고찰하였다.

• Nuclear Engineering and Technology
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• 제39권3호
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• pp.193-206
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• 2007

The Korea Atomic Energy Research Institute has developed an advanced fast reactor concept, KALIMER-600, which satisfies the Generation IV reactor design goals of sustainability, economics, safety, and proliferation resistance. The concept enables an efficient utilization of uranium resources and a reduction of the radioactive waste. The core design has been developed with a strong emphasis on proliferation resistance by adopting a single enrichment fuel without blanket assemblies. In addition, a passive residual heat removal system, shortened intermediate heat-transport system piping and seismic isolation have been realized in the reactor system design as enhancements to its safety and economics. The inherent safety characteristics of the KALIMER-600 design have been confirmed by a safety analysis of its bounding events. Research on important thermal-hydraulic phenomena and sensing technologies were performed to support the design study. The integrity of the reactor head against creep fatigue was confirmed using a CFD method, and a model for density-wave instability in a helical-coiled steam generator was developed. Gas entrainment on an agitating pool surface was investigated and an experimental correlation on a critical entrainment condition was obtained. An experimental study on sodium-water reactions was also performed to validate the developed SELPSTA code, which predicts the data accurately. An acoustic leak detection method utilizing a neural network and signal processing units were developed and applied successfully for the detection of a signal up to a noise level of -20 dB. Waveguide sensor visualization technology is being developed to inspect the reactor internals and fuel subassemblies. These research and developmental efforts contribute significantly to enhance the safety, economics, and efficiency of the KALIMER-600 design concept.

• 대한핵의학회지
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• 제24권1호
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• pp.101-107
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• 1990

To develop $^{131}I-labelled$ m-iodobeneylguanidine $(^{131}I-MIBG)$, various experiments such as synthesis of MIBG, establishment of labelling conditions, determination of radiochemical purity, and examination of stability were carried out. 1) m-Iodobenzylguanidine (MIBG) sulfate was synthesized with a total yield of 62.4% by the condensation of m-iodobenzylamine hydrochloride with cyanamide via MIBG bicarbonate. Its physical properties, IR, $^1H-NMR$, and elemental analysis data were nearly identical to those of literature. 2) Freeze-dried or vacuum-dried kit vials were prepared from the mixture so as to contain MIBG (2 mg), ascorbic acid (10 mg), copper (II) sulfate (0.14 mg), and tin (II) sulfate (0.5 mg) per vial. Copper ( I ) catalyzed radioiodination of MIBG was carried out using kit vials and 0.01 M $H_2SO_4$ as solvent at $100^{\circ}C$ for 30 min under nitrogen atmosphere (optimal conditions). Labelling yield was 98% and radiochemical purity was 99.5%, respectively. 3) Solid-phase radioiodination of MIBG was carried out at $155^{\circ}C$ for 30 min using the prepared vials to contain MIBG (2 mg) and ammonium sulfate (10 mg). Duplicate reactions under the same conditions showed labelling yield of 95% and radiochemical purity of 99.5%. 4) $^{131}I-MIBG$ prepared either by catalytic or by solid-phase exchange method showed radio-chemical purity of 99% even after 3 days storing at room temperature.

• Biomolecules & Therapeutics
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• 제29권1호
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• pp.90-97
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• 2021

Ultraviolet B (UVB) radiation causes DNA base modifications. One of these changes leads to the generation of 8-oxoguanine (8-oxoG) due to oxidative stress. In human skin, this modification may induce sunburn, inflammation, and aging and may ultimately result in cancer. We investigated whether phloroglucinol (1,3,5-trihydroxybenzene), by enhancing the expression and activity of 8-oxoG DNA glycosylase 1 (Ogg1), had an effect on the capacity of UVB-exposed human HaCaT keratinocytes to repair oxidative DNA damage. Here, the effects of phloroglucinol were investigated using a luciferase activity assay, reverse transcription-polymerase chain reactions, western blot analysis, and a chromatin immunoprecipitation assay. Phloroglucinol restored Ogg1 activity and decreased the formation of 8-oxoG in UVB-exposed cells. Moreover, phloroglucinol increased Ogg1 transcription and protein expression, counteracting the UVB-induced reduction in Ogg1 levels. Phloroglucinol also enhanced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) as well as Nrf2 binding to an antioxidant response element located in the Ogg1 gene promoter. UVB exposure inhibited the phosphorylation of protein kinase B (PKB or Akt) and extracellular signal-regulated kinase (Erk), two major enzymes involved in cell protection against oxidative stress, regulating the activity of Nrf2. Akt and Erk phosphorylation was restored by phloroglucinol in the UVB-exposed keratinocytes. These results indicated that phloroglucinol attenuated UVB-induced 8-oxoG formation in keratinocytes via an Akt/Erk-dependent, Nrf2/Ogg1-mediated signaling pathway.