• Title/Summary/Keyword: half-dose

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Simplified HPLC Method for the Determination of Mirtazapine in Human Plasma and Its Application to Single-dose Pharmacokinetics

  • Gwak Hye-Sun;Lee Na-Young;Chun In-Koo
    • Biomolecules & Therapeutics
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    • v.14 no.1
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    • pp.40-44
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    • 2006
  • Mirtazapine is an antidepressant agent with dual action on both the noradrenergic and serotonergic neurotransmitter systems. A simple high performance liquid chromatographic method has been developed and validated for the quantitative determination of mirtazapine in human plasma. A reversed-phase Cl8 column was used for the determination of mirtazapine with a mobile phase composed of 0.01M ammonium acetate solution (pH 4.2) and acetonitrile (75:25, v/v%) at a flow rate of 1.2 mL/min. Terazosin hydrochloride was used as an internal standard. The fluorescence detector was set at excitation and emission wavelengths of 290 and 350 nm, respectively. Intra- and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification of 3 ng/mL. Mirtazapine was stable in human plasma under various storage conditions. This method was used successfully for a pharmacokinetic study using plasma samples after oral administration of a single 30 mg dose as mirtazapine base to 8 healthy volunteers. The maximum plasma concentration of mirtazapine was $64.1{\pm}28.0ng/mL$ at 1.8 h, and the area under the curve and elimination half-life were calculated to be $674.1{\pm}218.5ng\;h/mL\;and\;23.4{\pm}3.8h$, respectively.

IMAGING IN RADIATION THERAPY

  • Kim Si-Yong;Suh Tae-Suk
    • Nuclear Engineering and Technology
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    • v.38 no.4
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    • pp.327-342
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    • 2006
  • Radiation therapy is an important part of cancer treatment in which cancer patients are treated using high-energy radiation such as x-rays, gamma rays, electrons, protons, and neutrons. Currently, about half of all cancer patients receive radiation treatment during their whole cancer care process. The goal of radiation therapy is to deliver the necessary radiation dose to cancer cells while minimizing dose to surrounding normal tissues. Success of radiation therapy highly relies on how accurately 1) identifies the target and 2) aim radiation beam to the target. Both tasks are strongly dependent of imaging technology and many imaging modalities have been applied for radiation therapy such as CT (Computed Tomography), MRI (Magnetic Resonant Image), and PET (Positron Emission Tomogaphy). Recently, many researchers have given significant amount of effort to develop and improve imaging techniques for radiation therapy to enhance the overall quality of patient care. For example, advances in medical imaging technology have initiated the development of the state of the art radiation therapy techniques such as intensity modulated radiation therapy (IMRT), gated radiation therapy, tomotherapy, and image guided radiation therapy (IGRT). Capability of determining the local tumor volume and location of the tumor has been significantly improved by applying single or multi-modality imaging fur static or dynamic target. The use of multi-modality imaging provides a more reliable tumor volume, eventually leading to a better definitive local control. Image registration technique is essential to fuse two different image modalities and has been In significant improvement. Imaging equipments and their common applications that are in active use and/or under development in radiation therapy are reviewed.

Chlorella의 생리적, 생화학적 제활성에 미치는${\gamma}$-선의 영향

  • 이영록
    • Journal of Plant Biology
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    • v.7 no.3
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    • pp.9-14
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    • 1964
  • The sensitivities of Chlorella ellipsoidea to ${\gamma}$-ray from Cobalt-60 were determined by measuring the photosynthetic and respiratory activities and the changes in phosphate contents in various fractions of the irradited cells, which were further grown in a standard medium after irradiation, were compared to those of non-irradiated normal cells. The photosynthetic and repiratory activities of the cells were almost inversely proportional to the dose of ${\gamma}$-ray irradiated and the photosynthetic activity was more sensitive than the respiratory activity of the cells. The most sensitive to ${\gamma}$-ray was growth activity, followed by photosynthesis, exogenous and endogenous respirations of the cells in decreasing order. Chlorella cells were so resistant to ${\gamma}$-ray comapred with other organisms that about 280,000 r dose of ${\gamma}$-ray irradiaton was necessary to reduce as much as half the subsequent photosynthetic activity. When the irradiated algae were further cultured in a standard medium, the phosphate contents in the fraction of DNA, RNA and phosphoprotein decreased considerably compared with those of non-irradiated normal cells, while the phosphate contents in the fraction of polyphosphates increased than those of control. Therefore, it was deduced that ${\gamma}$-ray inhibited the synthesis of DNA from polyphosphates, that the growth of Chlorella cells were consequently retarded.

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Bioavailability and Comparative Pharmacokinetics of Two Enrofloxacin Formulations in Broiler Chickens (육계에서 경구투여시 enrofloxacin 제제에 따른 생체이용율 및 약물동태)

  • 윤효인;박승춘
    • Journal of Veterinary Clinics
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    • v.14 no.2
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    • pp.195-200
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    • 1997
  • In order to compare the pharmacokinetic profiles of enrofloxacin-HCL)ENFLX-HCL) and enrofloxacin-KOH (ENFLX-KOH) after oral administration in broiler chickens, the study was performed. The chickens used in this study weighed $1.82 {\pm}0.2 kg$ and clinically healthy. The dose of intravenous and lral administration was 5 mg per kg of body weight as enrofloxacin. After intravenous injection of enrofloxacin, it showed two-compartment model with the rapid distribution phase and the slow elimination phase. The mean apparent volume of distribution (Vd) was 2.70 l/kg. The mean half-life of elimination and distribution showed 8.26 h and 0.44 h, respectively. The mean area under curve (AUC) was calculated as $19.7 {\mu} g{\cdot} h/ml$. After oral administration of ENFLX-HCL and ENFLX-KOH with a rate of dose 5 mg of enrofloxacin/kg of body weight, Both of the products were showed one-compartment model unlike that of i.v. enrofloxacin standard solution showed the mean bioavailability of 79.64% for the ENFLX-KOG and 86.24% for the ENFLX-HCL. The mean total body clearance of the former was 0.24 l/kg/h and the latter 0.42 l/kg/h. Both enorfloxacin formulations seemed to have good tissue distribution and penetration as indicated by large volume of distribution : 2.72 l/kg for the -KOH and 4.44 l/kg for the -HCL. With the results obtained in this study, ENFLX-HCL could be used in place of its salt form in chickens.

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Women's Calcium Intake during Late Pregnancy and Breastfeeding (일 지역 여성의 임신기와 수유기 칼슘섭취 양상)

  • Ahn, Suk-Hee;Kim, Jin-Hee
    • Journal of muscle and joint health
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    • v.18 no.1
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    • pp.63-72
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    • 2011
  • Purpose: The purpose of the study was to identify the amount of calcium intake during late pregnancy and breastfeeding and compare the differences in the amount of calcium by subjects' characteristics. Methods: With a descriptive survey design, 121 Korean breastfeeding women were recruited in a community setting. The list of foods and drinks with calcium extracted from the study of Song and So (2007) was used to measure the amount of calcium intake during pregnancy and lactation. The subjects' characteristics were collected to identify differences in the amount of calcium intake. Results: Mean age of the women was 31 years old. Amount of calcium intake was 568mg per day during late pregnancy and 431mg per day during breastfeeding. These amounts were quite lower than a recommended dose that adult women should consume a daily minimum of 1,000mg of calcium. Women who had higher household income and attending experience for nutritional education took more calcium during breastfeeding and late pregnancy, respectively. Conclusion: More than a half of the breast-feeding women do not consume the recommended dose of calcium. Education for proper calcium consumption during pregnancy and lactation should be an additional subject in the prenatal and breastfeeding education program for women's bone health.

Development of Frequency Weighting Shape for Evaluation of Discomfort due to Vertical Whole-body Shock Vibration (수직방향 전신 충격진동의 불편함 평가를 위한 주파수가중곡선 개발)

  • Ahn, Se-Jin;Jeong, Weui-Bong
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.6 s.111
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    • pp.658-664
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    • 2006
  • Shock vibrations are usually experienced in vehicles excited by impulsive input, such as bumps. The frequency weighting functions of the current standards in ISO 2631 and BS 6841 are to help objectively predict the amount of discomfort of stationary vibration. This experimental study was designed to develop frequency weighting shape for shock vibration having various fundamental frequencies from 0.5 to 16Hz. The specks were produced from the response of single. degree-of-freedom model to a half-sine force input. Fifteen subjects used the magnitude estimation method to judge the discomfort of vertical shock vibration generated on the rigid seat mounted on the simulator. The magnitudes of the shocks, expressed in terms of both peak-to-peak value and un-weighted vibration dose values (VDVs) , were correlated with magnitude estimates of the discomfort. The frequency weighting shapes from the correlation were developed and investigated having nonlinearity due to the magnitude of the shock.

Anti-inflammatory, Anti-glycation, Anti-tyrosinase and CDK4 Inhibitory Activities of Alaternin (=7-Hydroxyemodin)

  • Bhatarrai, Grishma;Choi, Jeong-Wook;Seong, Su Hui;Nam, Taek-Jeong;Jung, Hyun Ah;Choi, Jae Sue
    • Natural Product Sciences
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    • v.27 no.1
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    • pp.28-35
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    • 2021
  • The aim of this study was to anatomize the therapeutic potential of alaternin (=7-hydroxyemodin) against inflammation, advanced glycation end products (AGEs) formation, tyrosinase, and two cyclin-dependent kinases (CDKs), CDK2 and CDK4, and compare its potency with emodin. Alaternin showed lower cytotoxicity and higher dose-dependent inhibition against lipopolysaccharide (LPS) induced nitric oxide (NO) production with half maximal inhibitory concentration (IC50) of 18.68 µM. Similarly, alaternin efficaciously inhibited biotransformation of fluorescent AGEs and amyloid cross-β structure on the bovine serum albumin (BSA)-glucose-fructose system, five times more than emodin. Interestingly, alaternin also showed selective activity against CDK4 at 170 µM, whereas emodin inhibited both CDK2 and CDK4 at a concentration of 17 and 380 µM respectively. In addition, alaternin showed dose-dependent inhibitory activity against mushroom tyrosinase with inhibition percentage of 35.84 % at 400 µM. Altogether, alaternin with pronounced inhibition against inflammatory mediator (NO), glycated products formation, and targeted inhibition towards CDK4 receptor can be taken as an important candidate to target multiple diseases.

Calculation of X-ray spectra characteristics and kerma to personal dose equivalent Hp(10) conversion coefficients: Experimental approach and Monte Carlo modeling

  • Arectout, A.;Zidouh, I.;Sadeq, Y.;Azougagh, M.;Maroufi, B.;Chakir, E.;Boukhal, H.
    • Nuclear Engineering and Technology
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    • v.54 no.1
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    • pp.301-309
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    • 2022
  • This work aims to establish some X-ray qualities recommended by the International Standard Organization (ISO) using the half-value layer (HVL) and Hp(10) dosimetry approaches. The HVL values of the following qualities N-60, N-80, N-100, N-150 and N-250 were determined using various attenuation layers. The obtained results were compared to those of reference X-ray beam qualities and a good agreement was found (difference less than 5% for all qualities). The GAMOS (Geant4-based Architecture for Medicine-Oriented Simulations) radiation transport Monte Carlo toolkit was employed to simulate the production of X-ray spectra. The characteristics HVLs, mean energy and the spectral resolution of simulated spectra have been calculated and turned out to be conform to the ISO reference ones (difference less than the limit allowed by ISO). Furthermore, the conversion coefficients from air kerma to personal dose equivalent for simulated and measured spectra were fairly similar (the maximum difference less than 4.2%).

The characteristics on dose distribution of a large field (넓은 광자선 조사면($40{\times}40cm^2$ 이상)의 선량분포 특성)

  • Lee Sang Rok;Jeong Deok Yang;Lee Byoung Koo;Kwon Young Ho
    • The Journal of Korean Society for Radiation Therapy
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    • v.15 no.1
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    • pp.19-27
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    • 2003
  • I. Purpose In special cases of Total Body Irradiation(TBI), Half Body Irradiation(HBI), Non-Hodgkin's lymphoma, E-Wing's sarcoma, lymphosarcoma and neuroblastoma a large field can be used clinically. The dose distribution of a large field can use the measurement result which gets from dose distribution of a small field (standard SSD 100cm, size of field under $40{\times}40cm2$) in the substitution which always measures in practice and it will be able to calibrate. With only the method of simple calculation, it is difficult to know the dose and its uniformity of actual body region by various factor of scatter radiation. II. Method & Materials In this study, using Multidata Water Phantom from standard SSD 100cm according to the size change of field, it measures the basic parameter (PDD,TMR,Output,Sc,Sp) From SSD 180cm (phantom is to the bottom vertically) according to increasing of a field, it measures a basic parameter. From SSD 350cm (phantom is to the surface of a wall, using small water phantom. which includes mylar capable of horizontal beam's measurement) it measured with the same method and compared with each other. III. Results & Conclusion In comparison with the standard dose data, parameter which measures between SSD 180cm and 350cm, it turned out there was little difference. The error range is not up to extent of the experimental error. In order to get the accurate data, it dose measures from anthropomorphous phantom or for this objective the dose measurement which is the possibility of getting the absolute value which uses the unlimited phantom that is devised especially is demanded. Additionally, it needs to consider ionization chamber use of small volume and stem effect of cable by a large field.

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Tumor Necrosis Factor Receptor (TNFR)-associated factor 2 (TRAF2) is not Involved in GM-CSF mRNA Induction and TNF-Mediated Cytotoxicity

  • Kim, Jung-Hyun;Cha, Myung-Hoon;Lee, Tae-Kon;Seung, Hyo-Jun;Park, Choon-Sik;Chung, Il-Yup
    • Journal of Microbiology
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    • v.37 no.2
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    • pp.111-116
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    • 1999
  • Tumor necrosis factor receptor (TNFR)-associated factor 2 (TRAF2) is known to act as a signal transducer that connects TNFR2 to its downstream effector functions such as proliferation of thymocytes, regulation of gene expression, and cell death. TRAF2 consists of largely two domains, the N-terminal half that contains a signal-emanating region and the C-terminal half that is responsible for binding to the intracellular region of TNFR2. In this study, we examined the possible roles of TRAF2 in granulocyte-macrophage colony-stimulating factor (GM-CSF) gene expression and cell death. A truncated mutant of TRAF2 ( 2-263) that contains only a C-terminal half was generated, and transiently transfected to the A549 cell, a human lung cancer cell line, and L929 cell, a murine TNF-sensitive cell line. GM-CSF mRNA was induced in untransfected A540 cells both in dose- and time-dependent manner upon the exposure of TNF. However, neither the full length TRAF2 nor the mutant altered GM-CSF mRNA production regardless of the presence or absence of TNF. Furthermore, neither TRAF2 versions significantly changed the cytotoxic effect of TNF on L929 cells. These data suggest that TRAF2 may not be involved in the signal transduction pathway for GM-CSF gene induction and cell death mediated by TNF.

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