• 제목/요약/키워드: repeated dose

검색결과 495건 처리시간 0.02초

Ginkgo Biloba Extract가 C3H 마우스 섬유육종의 저산소세포 분획에 미치는 영향 (The Effect of Ginkgo Biloba Extract on Hypoxic Fraction of C3H Mouse Fibrosarcoma)

  • 조철구;이춘자;하성환;박찬일
    • Radiation Oncology Journal
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    • 제13권3호
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    • pp.205-214
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    • 1995
  • 목적 : C3H 마우스의 섬유육종에 있어서 저산소 분획 및 대사상태에 미치는 Ginkgo biloba extract (GBE)의 영향을 알아보기 위해 본 실험을 시행하였다. 방법 : C3H 마우스의 우측 대퇴부에 이식한 섬유육종이 6mm가 되었을 때 $TCD_50$를 이용하여 저산소 세포 분획을 계산하였다. 방사선은 GBE (100mg/kg) 1회 투여시는 1시간 후에, 2회 투여시는 24시간 간격으로 2회 투여후 1시간 경과후 방사선을 조사하였으며, 산소공급이 충분한 상태와 결찰에 의한 저산소 상태에서 각각 조사하였다. 종양의 대사 상태 변화를 알아보기 위해 GBE 투여 전과 투여 후 1시간에 각각 ^{31}P$ 핵자기 공명 분광분석법을 시행하였다. 결과 : 종양 치료방사선량은 결찰에 의한 저산소 상태시 81.7 (77.7 - 86.0) Gy, 정상 혈류상태시는 69.6 (66.8 - 72.5) Gy 였으며, GBE 1회 투여한 경우에는 67.5 (64.1 - 71.1) Gy, GBE 2회 투여시는 62.2 (59.1 - 65.5) Gy 로서, 2회 투여시 현저히 감소하였다. 이로부터 계산한 저산소 세포 분획은 정상 혈류 상태에서는 $10.6{\%}$, GBE 1회 투여시는 $7.2{\%}$로 다소 감소하였고, GBE 2회 투여시는 $2.7{\%}$로 현저히 감소하였다. ^{31}P$ 핵자기공명분광분석결과 PCr/Pi 비는 대조군 $0.27{\pm}0.04$, GBE 1회 투여시는 $0.40{\pm}0.04$, 2회 투여시는 $0.71{\pm}0.04$로 GBE 2회 투여시 종양의 대사상태가 현저히 호전되었다. 결론 : 이상의 결과를 종합해 볼 때, GBE 의 투여에 의해 혈류량과 산소 및 영양분의 공급이 증가함에 따라, 저산소세포분획이 감소하였고, 종양의 대사 상태가 호전되어, 종양의 방사선에 대한 감수성이 높아졌다고 판단되었다.

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

  • 이원정;정순철
    • 한국방사선학회논문지
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    • 제13권4호
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    • pp.573-579
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    • 2019
  • 환자 피폭선량 관리에 입사표면선량(ESD, entrance surface dose)이 국내외적으로 진단참고준위(국내 흉부촬영 $340{\mu}Gy$)로 사용되고 있지만, ESD측정을 위해서는 선량계가 필요하다. 하지만 대부분 병의원에서는 선량계가 구비되어 있지 않고 정기검사 시 전문 업체 측정에 의해 확인할 수 있다. 따라서 본 연구에서는 흉부 디지털촬영에서 사용자가 쉽게 ESD를 예측할 수 있는 방법에 대해 알아보았다. 흉부 디지털촬영에서 평판형 디텍터(FP, Flat-panel detector)와 IP (Imaging plate detector)를 대상으로 하였고, ESD는 선량계(XI-Platinum, Unfors, Sweden)를 흉부 팬텀(07-646 Duke QC chest phantom, Supertech, Elkhart, USA)의 중앙 표면에 부착시킨 후, 튜브와 디텍터를 180cm 거리를 유지시켜 각 노출조건 조합(관전압과 노출선량)에서 3회 반복측정한 후 평균값을 얻었다. 흉부 팬텀 영상의 다이콤 헤더 정보에서 FP영상은 선량면적곱(DAP, dose-area product)을 확인하였고, IP영상에서는 노출 지수(EI, exposure index)를 확인하였다. 단순선형회귀분석을 통해 FP촬영에서 DAP로부터, IP촬영에서 EI로부터 ESD를 예측할 수 있는 회귀방정식($y={\alpha}+{\beta}X$, ${\alpha}$=직선의 절편, ${\beta}$=직선의 기울기)을 구하였다. FP가 IP 보다 유의하게 낮은 선량을 보였고($85.7{\mu}Gy$ vs. $124.6{\mu}Gy$, p=0.017), 두 디텍터 모두 ESD와 화질 간에 높은 양의 상관성을 보였다. FP에서 수정된 R 제곱(adjusted R2)은 0.978로 ESD의 변동은 DAP 변동에 의해 97.8%의 높은 설명력을 보였다. 단순 회귀식은 $ESD=0.407+68.810{\times}DAP$ 이었다. 위의 회귀식을 이용하여 국내 권고선량($340{\mu}Gy$)과 같은 DAP를 추정한 결과($DAP=0.021+0.014{\times}340{\mu}Gy$), DAP는 4.781 이었다. IP에서 수정된 R 제곱(adjusted R2)은 0.645로 ESD의 변동은 EI 변동에 의해 64.5%의 설명력을 보였다. 단순 회귀식은 $ESD=-63.339+0.188{\times}EI$ 이었다. 위의 회귀식을 이용하여 국내 권고선량($340{\mu}Gy$)과 같은 EI를 추정한 결과($EI=565.431+3.481{\times}340{\mu}Gy$), EI는 1748.97 이었다. 흉부 디지털 촬영에서는 팍스 워크스테이션 영상의 다이콤 헤더 정보에서 ESD를 사용자가 쉽게 예측할 수 있다.

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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    • 제16권1호
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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
    • 대한한의학회지
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    • 제30권3호
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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
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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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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    • 제15권2호
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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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    • 제28권4호
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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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    • 제28권6호
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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.

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

  • 차봉석;박정균;박종구;장세진
    • Journal of Preventive Medicine and Public Health
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    • 제25권2호
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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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간섭전류자극이 말초 혈류속도에 미치는 영향 (Effects of Interferential Current Stimulation on the Peripheral Blood Velocity in Healthy Subjects)

  • 박장성;이재형
    • The Journal of Korean Physical Therapy
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    • 제11권2호
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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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