• Title/Summary/Keyword: repeated dose

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Prediction of Entrance Surface Dose in Chest Digital Radiography (흉부 디지털촬영에서 입사표면선량 예측)

  • Lee, Won-Jeong;Jeong, Sun-Cheol
    • Journal of the Korean Society of Radiology
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    • v.13 no.4
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    • pp.573-579
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    • 2019
  • The purpose of this study is predicted easily the entrance surface dose (ESD) in chest digital radiography. We used two detector type such as flat-panel detector (FP) and IP (Imaging plate detector). ESD was measured at each exposure condition combined tube voltage with tube current using dosimeter, after attaching on human phantom, it was repeated 3 times. Phantom images were evaluated independently by three chest radiologists after blinding image. Dose-area product (DAP) or exposure index (EI) was checked by Digital Imaging and Communications in Medicine (DICOM) header on phantom images. Statistical analysis was performed by the linear regression using SPSS ver. 19.0. ESD was significant difference between FP and IP($85.7{\mu}Gy$ vs. $124.6{\mu}Gy$, p=0.017). ESD was positively correlated with image quality in FP as well as IP. In FP, adjusted R square was 0.978 (97.8%) and linear regression model was $ESD=0.407+68.810{\times}DAP$. DAP was 4.781 by calculating the $DAP=0.021+0.014{\times}340{\mu}Gy$. In IP, adjusted R square was 0.645 (64.5%) and linear regression model was $ESD=-63.339+0.188{\times}EI$. EI was 1748.97 by calculating the $EI=565.431+3.481{\times}340{\mu}Gy$. In chest digital radiography, the ESD can be easily predicted by the DICOM header information.

Effects of Natrually Occurring Furanocoumarins on Lipid Peroxidation and Carbon Tetrachloride Induced Hapatotoxicity in Mice

  • Shin, Kuk-Hyun;Woo, Won-Sick;Moon, Ki-Ho;Yoo, Seung-Jo
    • Archives of Pharmacal Research
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    • v.16 no.1
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    • pp.13-17
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    • 1993
  • Several naturally occurring furanocoumarins significantly inhibited microsomal lipid peroxidation not only mediated by endogeneous iron and NADPH but also initiated by $CCL_4$ metabolites, phellopterin, a potent inhibibitor of cytochrome p-450, exhibited an almost complete inhibition of $CCL_4$-induced hepatotoxicity as measured by sGPT activity 24 hr after $CCL_4$ intoxication, whereas other furanocoumarins such as imperation, byakangelicin and oxypeucedanin methanolate exerted no protective effect. When compared with other cytochrome P-450 inhibitors(SKF-52A, AIA) and silymarin given at the same dose level $(ED_{50})$, phellopterin still showed a significant inhibition of hepatotoxicity which was even stronger than that of AIA, known as a typical suicide inhibitor. Phellopterin was partially effective when given 30 min after $CCL_4$ treatment. Repeated administrations of phellopterin, however, resulted in a complete loss of the protection against $CCL_4$-induced hepatotoxicity.

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Four-week Repeated Dose Toxicity Test for Myelophil in SD Rats

  • Jung, Jong-Mi;Shin, Jang-Woo;Son, Jin-Young;Seong, Nak-Won;Seo, Dong-Seok;Cho, Jung-Hyo;Cho, Chong-Kwan;Son, Chang-Gue
    • The Journal of Korean Medicine
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    • v.30 no.3
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    • pp.79-85
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    • 2009
  • Aim : To evaluate the pharmaceutical safety of the herbal formula Myelophil, composed of Astragali Radix and Salviae Radix, via systemic subacute toxicological study using SD rats. Methods : Forty male and 40 female SD rats were fed with Myelophil (5000, 2500 or 1250 mg/10 mL/kg) or distilled water for four weeks. Adverse effects were examined intensively by comparing the differences between normal and drug-administered groups using clinical signs, necropsies, histopathologic findings, hematology, urinalysis, and blood biochemical analysis. Results : No altered clinical symptoms including body weight, diarrhea, anorexia, death, and abnormal necropsy of major organs were observed in male or female rats. No drug-induced abnormalities in histopathological finding, hematological values, urinalysis, and blood biochemical values were found at any doses of Myelophil. Conclusion : Myelophil should be very safe when used in a clinical application with a wide therapeutic index.

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Inhalation Toxicity of 1-Bromoprpane (1-BP)

  • Kim, Hyeon-Yeong;Lee, Jun-Yeon;Lim, Cheol-Hong;Chung, Yong-Hyun;Han, Jung-Hee;Jeong, Jae-Hwang;Lee, Sung-Bae;Jhoon, Yoon-Sook;Lee, Yong-Muk
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.05a
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    • pp.126-126
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    • 2001
  • The purpose of this study was to investigate the acute(4 hrs) and repeated-dose(6 hrs a day, 5 days a week, 8 weeks) toxic effects of 1-bromopropane(1-BP) on Sprague-Dawley (SD) rats which were treated by inhalation. The results were as follows ;(omitted)

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Selection of a L-Lysine-Overproducing Strain of the Red Seaweed Porphyra suborbiculata (Rhodophyta) through Mutation and Analog Enrichment

  • Luyen, Quoc-Hai;Chowdhury, Muhammad Tanvir Hossain;Choi, Jae-Suk;Kang, Ji-Young;Park, Nam-Gyu;Hong, Yong-Ki
    • Fisheries and Aquatic Sciences
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    • v.15 no.2
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    • pp.145-150
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    • 2012
  • An improved strain of the red seaweed Porphyra suborbiculata containing an increased amount of the essential amino acid L-lysine was obtained through mutation and analog enrichment. Mutagenesis using a 10% lethal dose of ultraviolet irradiation and an enrichment culture with the L-lysine analog aminoethyl-L-cysteine (AEC) was repeated to select the most productive strain using monospores of P. suborbiculata. The concentrations of AEC required to produce 50 and 100% inhibition of survival were 60 and 115 mM in the parent strain, and 72 and 135 mM in the selected AEC-resistant strain, respectively. The AEC-resistant strain, L130, produced 1.74-fold more lysine compared to its parent strain. Thus, mutagenesis with analog enrichment shows promise for selecting seaweed strains that can overproduce this essential amino acid.

A New Rat Model of Cisplatin-induced Neuropathic Pain

  • Lin, Hai;Heo, Bong Ha;Yoon, Myung Ha
    • The Korean Journal of Pain
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    • v.28 no.4
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    • pp.236-243
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    • 2015
  • Background: Chemotherapy-induced peripheral neuropathy is a major side effect of anti-cancer drugs, and our knowledge of its mechanisms is lacking. Several models for chemotherapy-induced neuropathy have been introduced. However, the outcomes of these models differ significantly among laboratories. Our object was to create a model of chemotherapy-induced neuropathy in rats with cancer. Methods: Female Sprague-Dawley rats were used. Mammary rat metastasis tumor (MRMT-1) cells were implanted subcutaneously in rats. Chemotherapy-induced peripheral neuropathy was induced by injection of cisplatin once a day for four days. The responses to mechanical and thermal stimuli were examined using von Frey filaments, acetone, and radiant heat. Results: Cisplatin (2 mg/kg/day) produced mechanical allodynia, while it did not induce cold allodynia or thermal hyperalgesia. This dose of cisplatin could work successfully against cancer. Body weight loss was not observed in cisplatin-treated rats, nor were other abnormal behaviors noted in the same rats. Conclusions: Repeated injection of intraperitoneal cisplatin induced peripheral neuropathic pain in rats. Thus, this type of rat model has broad applicability in studies related to searching for the mechanism of cisplatin-induced mechanical allodynia and agents for the treatment of neuropathic pain.

Improvement of Memory by Dieckol and Phlorofucofuroeckol in Ethanol-Treated Mice: Possible Involvement of the Inhibition of Acetylcholinesterase

  • Myung Chang-Seon;Shin Hyeon-Cheol;Bao Hai Ying;Yeo Soo Jeong;Lee Bong Ho;Kang Jong Seong
    • Archives of Pharmacal Research
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    • v.28 no.6
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    • pp.691-698
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    • 2005
  • Phlorotannins, the polyphonic compounds found in brown Eisenia and Ecklonia algae, have several pharmacologically beneficial effects such as anti-inflammation. In addition, our recent data show that these compounds may improve the cognitive functions of aged humans suggesting the potential ability to enhance memory in several neurodegenerative disorders. To examine the experimental hypothesis that two effective components of Ecklonia cava, dieckol and phlorofucofuroeckol (PFF), have memory-enhancing abilities, both were administered orally to mice before a passive avoidance test. The repeated administration of either dieckol or PFF dose-dependently reduced the inhibition of latency by the administration of ethanol. To investigate the mode of memory-enhancing actions, the levels of major central neurotransmitters in three different regions (striatum, hippocampus, and frontal cortex) of the mouse brain were measured. The levels of some of the neurotransmitters were significantly changed by ethanol. Both dieckol and PFF altered the levels of some neurotransmitters modified by the ethanol treatment. It is noteworthy that both dieckol and PFF increased the level of acetylcho-line, and they exerted anticholinesterase activities. Overall, the memory-enhancing abilities of dieckol and PFF may result from, at least in part, the increment of the brain level of acetylcho-line by inhibiting acetylcholinesterase.

Effects of Multiple Exposures to Pesticides on Plasma Cholinesterase Activity and p-nitrophenol Excretion in Rats (농약의 복합투여가 백서의 혈장 콜린에스테라제 활성도 및 요중 파라-니트로페놀 배설에 미치는 영향)

  • Cha, Bong-Suk;Park, Jung-Gyun;Park, Jong-Ku;Chang, Sei-Jin
    • Journal of Preventive Medicine and Public Health
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    • v.25 no.2 s.38
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    • pp.180-188
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    • 1992
  • The effects of multiple exposures to pesticides on plasma cholinesterase(ChE) activities and urinary p-nitrophenol excretion were evaluated in rats. Rats were received single dose i.p. with $LD_{50}/100(mg/kg)$ of organophosphorous(OP), organophosphorous-organochroline(OP-OC), organophosphorous-carbamate(OP-CAB), organophosphorous-organoarsenate(OP-OA) pesticides for 4 consecutive days. In repeated administration of pesticides, plasma ChE activities were decreased, but urinary p-nitrophenol were increased after the first injection and then decreased gradually The recovery rates of ChE activities and p-nitrophenol excretion at 48 hours after the fourth Injection were delayed in comparision with the baseline value of 24 hours before the first injection. Statistical significances were found between OP and other groups except OP-OA group after the second injection in plasma ChE activities, but in urinary p-nitrophenol excretion there was statistical significance only between OP and OP-CAB.

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Effects of Interferential Current Stimulation on the Peripheral Blood Velocity in Healthy Subjects (간섭전류자극이 말초 혈류속도에 미치는 영향)

  • Park Jang-Sung;Lee Jae-Hyoung
    • The Journal of Korean Physical Therapy
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    • v.11 no.2
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    • pp.37-42
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    • 1999
  • The purpose of this study was to determine whether percutaneous interferential current stimulation on thoracic sympathetic ganglia with amplitude modulated frequency (AMF) $90\~100$ bps and subthreshold of muscle contraction for 10 minutes on peripheral blood flow velocity in healthy subjects. Thirty-seven healthy volunteers were assigned randomly into an experimental group (n=25) and a control group (n=12). the experimental group received interferential current stimulation with subthreshold of the muscle contraction of current at AMF $90\~100$ bps on $1st\~5th$ thoracic sympathetic ganglial region for 10 minutes. The control group received same handling and electode placement, but no current was applied. Using a Doppler blood flow meter, the radial arterial blood flow velocities and the pulse raters were determined for two-way analysis of variance for repeated measures on time and group. There were no significant difference between the two groups with respect to the changes in arterial blood flow velocity and pulse rate over the four measurement times. Interferential current stimulation did not change in mean blood flow velocity and pulse rate. We conclude that interferential current stimulation on the thoracic sympathetic ganglia, as used in this study, did not dilate peripheral artery. This results suggests that interferential current stimulation dose not alter the activtiy of sympathetic nerve.

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Antioxidant Activity and Changes in Major Functional Components of Fermented Gastrodia elata Blume (발효 천마의 기능성 물질 함량 변화 및 항산화 활성)

  • Kim, Mi Hyun;Kim, Jong Gyu;Choi, Jae Hong
    • The Korean Journal of Food And Nutrition
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    • v.27 no.4
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    • pp.684-691
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    • 2014
  • This study was carried out to investigate the antioxidant activity and changes in major functional components of fermented Gastrodia elata Blume. Fermented G. elata Blume powder by Phellinus linteus repeated thrice ($3^{rd}$ FGP) showed more DPPH radical scavenging activity than a non-fermented G. elata Blume powder (NFGP), and once fermented G. elata Blume powder ($1^{st}$ FGP) at a concentration of 500 and 1,000 ppm. Free radical scavenging activity of $3^{rd}$ FGP was similar to that of BHA at a dose of 1,000 ppm. Moreover, the ABTS radical scavenging activity of the $3^{rd}$ FGP increased compared to NFGP and $1^{st}$ FGP at a concentration of 31.25 ppm. Total polyphenols and flavonoid contents were increased as fermentation progressed. Ergothioneine content was increased more than 8 times in the $1^{st}$ FGP, 3 times in the $3^{rd}$ FGP, respectively than NFGP. In conclusion, this study indicated that the antioxidant activity and functional component contents of G. elata Blume were increased depending on the fermentation number.