• Title/Summary/Keyword: organ distribution

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Pharmacokinetic Study on DWC-751, a New Cephalosporin, in Rats and Mice (신규 세파로스포린계 항생물질 DWC-751의 흰쥐 및 생쥐 체내동태)

  • 심창구;최은진;이성원;박남준;강영숙;유영효
    • Biomolecules & Therapeutics
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    • v.1 no.2
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    • pp.204-210
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    • 1993
  • The distribution and excretion of DWC-751, a new cephalosporin, were examined in rats and mice following a single intravenous administration. DWC-751 in plasma and urine was determined by both HPLC and microbiological assay. The plasma concentration of the drug declined biexponentially. The initial and terminal half lives of the drug were 3.0 and 28.3 min, respectively. Binding of the drug to plasma proteins was 42.3%. The distribution volume at steacly-state ($Vd_{ss}$) was only 0.341 ι/kg, which is well correlated with the low n-octanol/water partition coefficient of the drug ($K_{o/w{\cong}0$) Actually, the drug was distributed to liver, kidney and lung with very low organ/plasma concentration ratio. The drug, was excreted mainly via renal excretion, i.e., the total($CL_T$) and apparent renal($CL_{R}$) clearances of the drug were 10.8 and 7.5 ml/min/kg, respectively.

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Iris Pattern Positioning with Preserved Edge Detector and Overlay Matching

  • Ryu, Kwang-Ryol
    • Journal of information and communication convergence engineering
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    • v.8 no.3
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    • pp.339-342
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    • 2010
  • An iris image pattern positioning with preserved edge detector, ring zone and clock zone, frequency distribution and overlay matching is presented in this paper. Edge detector is required to be powerful and detail. That is proposed by overlaying Canny with LOG (CLOG). The two reference patterns are made from allocating each gray level on the clock zone and ring zone respectively. The normalized target image is overlaid with the clock zone reference pattern and the ring zone pattern to extract overlapped number, and make a matched frequency distribution to look through a symptom and position of human organ and tissue. The iterating experiments result in the ring and clock zone positioning evaluation.

Development of Specific organ targeting drug delivery system II : Physico-pharaceutical study on the crose-linked albumin microspheres containing cytarabine

  • Kim, Chong-Kook;Lee, Jin-Kyu;Lah, Woon-Lyong
    • Archives of Pharmacal Research
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    • v.9 no.1
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    • pp.39-43
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    • 1986
  • Bovine serum albumin microspheres containing cytarabine were prepared using cross-linking agent, formaldehyde. The shape and the size distribution of them were observed. The shape of them was spherical and the susrface was compact and smooth. The size distribution of them was affected by dispersion forces during emulsfication. The release of cytarabine from albumin microspheres was dependent upon cross-linking time, amount of cross-linking agent and drug/albumin ratio. However, the difference of drug release by the dispersion forces was not great. After release test, the shape of albumin microspheres was nonspherical and the albumin matrix seemed to be a little relaxed. The degradation tests of albumin microspheres by the proteolytic enzyme showed that albumin microspheres were progressively digested according to the cross-linking degree.

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Pharmacokinetics and Tissue Distribution of UTI in the Rat (랫드에서의 UTI의 약물동태학 및 조직 분포)

  • 정요찬;윤효인;조명행;박병권;발일현;김복환;송동호
    • Biomolecules & Therapeutics
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    • v.4 no.3
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    • pp.265-270
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    • 1996
  • The purpose of this study was to determine pharmacokinetic parameters and tissue distribution patters of urinary trypsin inhibitor(UTI) in Sprague-Dawley rats. $Na^{125}$I was conjugated to UTI to make $^{125}I-UTI$ and the concentrations were determined by $\gamma$-counter. With the aid of nonlinear least-square regression analysis for i.v bolus injection of 1,000 unit UTI including $^{125}I-UTI$, the temporal concentration curves were best fitted by 2-compartment open model. The distribution phase half-life was 0.39$\pm$0.02 hours whereas the elimination half-life was 12.99$\pm$1.05 hours in male rats. The volume of distribution and total body clearance in male rats were 0.28$\pm$0.01 1/kg and 83.16$\pm$1.15 ml/kg/h, respectively. We could not find any difference of pharmacokinetic parameters of UTI between male and female rats. UTI were distributed widely in rat organs. In both male and female rats, the kidney was the highest distributed organ. Amount of UTI in 24 hour cumulative urine in male rats was 36.22$\pm$8.74% and that in 48 hours was 43.32$\pm$10.55%. Excretion via feces was very scanty, with the 24 hours cumulative amount being only 2.76$\pm$0.97%. This data suggest the main excretion route of UTI is urine.

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Analysis on Induced Current Density inside Human Body by 60 Hz ELF Magnetic Fields (60Hz ELF자계에 의한 인체내부 유도 전류밀도 해석)

  • Min Suk Won;Song Ki Hyun
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.581-583
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    • 2004
  • This paper analysed the induced current density characteristics inside human body by extremely low frequency magnetic fields according to varying conductivities of human model. Human model was composed of several organs and other parts of 곳 human body, whose shapes were spheroids or cylinders. Organs taken into account were the brain, heart, lungs, liver and intestines. Applying the boundary element method to the human model, effects of the organ conductivity difference to the induced current distribution were estimated.

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Organ Dose Conversion Coefficients Calculated for Korean Pediatric and Adult Voxel Phantoms Exposed to External Photon Fields

  • Lee, Choonsik;Yeom, Yeon Soo;Griffin, Keith;Lee, Choonik;Lee, Ae-Kyoung;Choi, Hyung-do
    • Journal of Radiation Protection and Research
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    • v.45 no.2
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    • pp.69-75
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    • 2020
  • Background: Dose conversion coefficients (DCCs) have been commonly used to estimate radiation-dose absorption by human organs based on physical measurements of fluence or kerma. The International Commission on Radiological Protection (ICRP) has reported a library of DCCs, but few studies have been conducted on their applicability to non-Caucasian populations. In the present study, we collected a total of 8 Korean pediatric and adult voxel phantoms to calculate the organ DCCs for idealized external photon-irradiation geometries. Materials and Methods: We adopted one pediatric female phantom (ETRI Child), two adult female phantoms (KORWOMAN and HDRK Female), and five adult male phantoms (KORMAN, ETRI Man, KTMAN1, KTMAN2, and HDRK Man). A general-purpose Monte Carlo radiation transport code, MCNPX2.7 (Monte Carlo N-Particle Transport extended version 2.7), was employed to calculate the DCCs for 13 major radiosensitive organs in six irradiation geometries (anteroposterior, posteroanterior, right lateral, left lateral, rotational, and isotropic) and 33 photon energy bins (0.01-20 MeV). Results and Discussion: The DCCs for major radiosensitive organs (e.g., lungs and colon) in anteroposterior geometry agreed reasonably well across the 8 Korean phantoms, whereas those for deep-seated organs (e.g., gonads) varied significantly. The DCCs of the child phantom were greater than those of the adult phantoms. A comparison with the ICRP Publication 116 data showed reasonable agreements with the Korean phantom-based data. The variations in organ DCCs were well explained using the distribution of organ depths from the phantom surface. Conclusion: A library of dose conversion coefficients for major radiosensitive organs in a series of pediatric and adult Korean voxel phantoms was established and compared with the reference data from the ICRP. This comparison showed that our Korean phantom-based data agrees reasonably with the ICRP reference data.

An Effect of Time Gating Threshold (TGT) on the Delivered Dose at Internal Organ with Movement due to Respiration (호흡에 의해 내부 움직임을 갖는 장기에 전달되는 선량에서 Time Gating Threshold (TGT)의 효과)

  • Kim Yon Lae;Chung Jin Bum;Chung Won Kyun;Hong Semie;Suh Tae Suk
    • Progress in Medical Physics
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    • v.16 no.2
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    • pp.89-96
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    • 2005
  • In this study, we investigated the effect of time gating threshold on the delivered dose at a organ with internal motion by respiration. Generally, the internal organs have minimum motion at exhalation during normal breathing. Therefore to compare the dose distribution time gating threshold, in this paper, was determined as the moving region of target during 1 sec at the initial position of exhalation. The irradiated fields were then delivered under three conditions; 1) non-moving target 2) existence of the moving target in the region of threshold (1sec), 3) existence of the moving target region out of threshold (1.4 sec, 2 sec). And each of conditions was described by the moving phantom system. It was compared with the dose distributions of three conditions using film dosimetry. Although the treatment time increased when the dose distributions was obtained by the internal motion to consider the TGT, it could be obtained more exact dose distribution than in the treatment field that didn't consider the internal motion. And it could be reduced the unnecessary dose at the penumbra region. When we set up 1.4 sec of threshold, to reduce the treatment time, it could not be obtained less effective dose distribution than 1 sec of threshold. Namely, although the treatment time reduce, the much dose was distributed out of the treatment region. Actually when it is treated the moving organ, it would rather measure internal motion and external motion of the moving organ than mathematical method. If it could be analyzed the correlation of the internal and external motion, the treatment scores would be improved.

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Toxicity of Natural Uranium in Rats (천연우라늄의 독성에 관한 실험 연구)

  • Ryu, Yong-Wun;Lee, Jhin-Oh;Yun, Taik-Koo
    • Journal of Radiation Protection and Research
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    • v.11 no.1
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    • pp.44-50
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    • 1986
  • Tissue distribution and blood chemistry of uranium in serum levels of BUN, Creatinine, SGPT and SGOT were determined in rats after the administration of uranylnitrate. Determination of uranium in organ was done by radio activation analysis. Radioactivity of $^{239}Np$ in lung was higher than in other tissues (e.g. liver, kidneys, spleen, tibia, testes, stomach and brain). Correlations between BUN and Creatinine were positively increased after the administration of 25 mg/kg uranylnitrate. The SGPT and SGOT activities showed weak correlation with the control group. However, activities of SGPT and SGOT after the administration of lmg/kg uranylnitrate showed high peak at 90 min interval. Uranium uptake by liver and kidneys increased at early period and decreased immediately to the control level. Lung who confirmed to be the critical organ on toxic effect by uranylnitrate.

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