• Title/Summary/Keyword: Dose Rate

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A Research on Superparamagnetic Iron Oxide Nanoparticles' Toxicity to U373MG Cell and its Effect on the Radiation Survival Curve (산화철 나노입자의 U373MG 세포 독성평가 및 방사선 세포생존 곡선에 미치는 영향에 대한 연구)

  • Kang, Seonghee;Kim, Jeonghwan;Kim, Dokyung;Kang, Bosun
    • Journal of the Korean Society of Radiology
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    • v.6 no.6
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    • pp.507-513
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    • 2012
  • This research was performed to evaluate the superparamagnetic iron oxide nanoparticles'(SPIONs) cell toxicity and to measure the radiation cell survival curve changes of SPIONs-uptake glioblastoma multiforme cells. The results could be practically used as the fundamental data to ameliorate proton beam cancer therapy, for example, providing necessary GBM treatment dose in the proton beam therapy when the therapy takes advantage of SPIONs. The assessment of the toxicological evaluation of synthesized SPIONs was accomplished by MTT assay as an in vitro experiment. The results showed no meaningful differences in the cell survival rate at the $1-100{\mu}g/ml$ SPIONs concentrations, but the cell toxicity was shown as the cell survival rate decreased up to 74.2% at the $200{\mu}g/ml$ SPIONs concentration. Then, we measured each radiation cell survival curve for U373MG cells and SPIONs-uptake U373MG cells with 0~5 Gy of proton beam irradiations. It is learned from the analysis of the experimental results that the SPION-uptake cells' radiation survival rate was more rapidly decreased as the irradiation dose increased. In conclusion we confirmed that SPIONs-uptake in U373MG cells induces cell death at the much less dose than the lethal dose of SPION-non-uptake cell. This research shows that the therapeutic efficacy of glioblastoma multiforme treatment in proton beam therapy can be improved by SPIONs targeting to the GBM cells.

Fine Structural Modification of Mouse Ovarian Tissue by Irradiation of 6 MeV LINAC Radiation (6 MeV LINAC 방사선 조사에 의한 생쥐 난소조직의 미세구조 변화)

  • Yoon, Chul-Ho;Moon, Myung-Jin
    • Applied Microscopy
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    • v.33 no.2
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    • pp.117-130
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    • 2003
  • This research investigates the fine structural as well as the morphological changes of the mouse ovarian tissue after irradiation of various dose rates of 6 MeV LINAC radiation. The normal structure of the ovarian tissue is consisted of various stages of follicles including primordial and growing follicles, and ovarian stromal connectives. When we observed the ovarian tissues irradiated with a dose rate of 200 cGy/min using light and electron microscopes, granular cells in growing follicles are in irregular shape unlike normal follicles. Small segments of cells scattered in follicular antrum among granular cells. We could observe neutrophils and macrophages around the segments, which means the cells already got in the process of decease owing to the effects radiation. With coincident to the increase of the dose rate of x-ray irradiation as 400 or 600 cGy/min, the mature follicles appeared as an irregular form and the granular cells surrounding oocyte also deformed comparing to their normal counterparts. The granulosa cells within mature follicle are already occurred necrotic change and apoptosis. The nuclei in some cells got so fragmented that the segments formed the shape of a horseshoe or scattered in small and condensed pieces. All the cells at a granular layer irradiated with a dose rate of 600 cGy/min show typical characteristics of apoptosis. The neutrophils involved in inflammatory reaction appear evidently in follicular antrum of growing follicles, and macrophage scattered with residual and apoptotic bodies.

Efficacy of Isoproterenol as a Marker of Epidural Test Dose in Patients Anesthetized with Enflurane (Enflurane 전신마취중 경막외 시험용량의 표식자로서 Isoproterenol의 효율성)

  • Kim, Keon-Sik;Kang, Wha-Ja;Lee, Doo-Ik
    • The Korean Journal of Pain
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    • v.14 no.2
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    • pp.186-192
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    • 2001
  • Background: Epidural test doses containing epinephrine are an incomplete marker for the detection of inadvertent intravascular injection. Therefore, many investigators have attempted to find a more reliable marker as an alternative to epinephrine in adult patients anesthetized with enflurane. The present study was designed to test whether two different simulated intravenous test doses of isoproterenol could be used as a reliable marker for the detection of inadvertent intravascular injection in adult patients anesthetized with $O_2-N_2O$-enflurane. Methods: Forty healthy adult patients were anesthetized with 1% end-tidal enflurane and nitrous oxide after endotracheal intubation and were randomized to one of two groups according to the dose of isoproterenol. Group 1 and 2 (n = 20 each) received 3 ml of 1.5% lidocaine with 3 and 5 g isoproterenol intravenously, respectively, to simulate an intravascularly administered test dose. Heart rate (HR) and systolic blood pressure (SBP) were measured at 20-second intervals for 4 min after injection. Results: Mean maximal HR increases were $24{\pm}17$, $35{\pm}11$ bpm (P < 0.05), mean maximal SBP increases were $14{\pm}8$, $13{\pm}9$ mmHg and mean maximal SBP decreases $20{\pm}11$, $22{\pm}9$ mmHg following the IV injection of 3, $5{\mu}g$ isoproterenol, respectively. The incidence of hypotension was similar in both groups. Isoproterenol 3 and $5{\mu}g$ produced 75%, 100% sensitivity in the HR criteria ($\geq$ 20 bpm increase) and 60%, 70% sensitivity in the SBP criteria ($\geq$ 15 mmHg), respectively. Conclusions: These results indicate that based on the HR response, the epidural test dose containing $5{\mu}g$ isoproterenol to simulate an intravascular administration is a more reliable marker than $3{\mu}g$ isoproterenol in adult healthy patients during enflurane anesthesia.

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Preliminary Results on Food Consumpt ion Rates for Off-site Dose Calculation of Nuclear Power Plants (원전 주변 주민의 방사선량 평가를 위한 음식물 섭취량 조사 예비결과)

  • Lee Gab-Bock;Chung Yang-Geun;Bang Sun-Young;Kang Duk-Won
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2005.11a
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    • pp.307-316
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    • 2005
  • The Internal dose by food consumption mostly account for radiological dose of public around nuclear poller plants(NPP). But, food consumption rate applied to off-site dose calculation in Korea which is the result of field investigation around Kori NPP by the KAERI in 1988, is not reflected of the latest dietary characteristics. The Ministry of Health and Welfare Affairs has investigated the food and nutrition of nations every 3 years based on the Law of National Health Improvement. To update the food consumption rates of the maximum individual the analysis of the national food investigation results and field surveys around nuclear power plant sites have been carried out.

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Effects of Guanabenz on Renal Function in Dog (개의 신장기능에 미치는 Guanabenz의 영향)

  • Lee, Sang-Hyun;Ko, Suk-Tai
    • YAKHAK HOEJI
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    • v.32 no.4
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    • pp.258-273
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    • 1988
  • In this study attempts were made to observe the effects of guanabenz on renal function in dog, which manifests the antihypertensive action by inhibition of sympathetic tone through stimulating the presynaptic adrenoceptor (${\alpha}_2-adrenoceptor$). Guanabenz, when injected at a dose of $30.0{\mu}g/kg$, or infused at a dose of $3.0{\mu}g/kg/min$ intravenously, produced diuretic action with increased amounts of $Na^+\;and\;K^+$ in urine, and with decreased reabsorption rates of $Na^+\;and\;K^+$ in renal tubules. It was also observed that the rates of osmolar and free water clearances were increased, but the glomerular filtration rate and renal plasma flow were not changed. Guanabenz injected at a dose of $3.0{\mu}g/kg$ into a carotid artery or infused intravenously at a dose of $3.0{\mu}g/kg/min$ in a state of water diuresis elicited the diuretic action of the similar aspect as a case of guanabenz given intravenously. The diuretic action produced by guanabenz was completly blocked by pretreatment of i.v. prazosin, ${\alpha}_1-adrenoblocking$ agent, or of i.v. yohimbine, ${\alpha}_2-adrenergic$ blocking agent. Prazosin, when given into a renal artery, inhibited the diuretic action by i.v. guanabenz in only injected kidney, whereas in case of yohimbine the action was inhibited in both kidney. Guanabenz infused at a dose of $1.0{\mu}g/kg/min$ into a renal artery exhibited no significant changes of renal function in both kidney. In denervation experiments, guanabenz given intravenously produced typical diuretic action in innervated kidney, whereas in denervated kidney, it did not affect the action at initial period but exhibited the action with increase of only free water clearance at later period. These results suggest that guanabenz produced diuretic action in dog by inhibition of electrolyte reabsorption rates in renal tabules, mainly proximal tubule and of ADH release, which is mediated by stimulating of central sympathetic ${\alpha}_2-receptor$.

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A Study on Cardiotoxicity of DA-125, a New Anticancer Antibiotic (새로운 항암성 항생물질 DA-125의 심장독성에 대한 평가)

  • ;;;;;Toshihiko Watanabe
    • Biomolecules & Therapeutics
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    • v.1 no.1
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    • pp.9-19
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    • 1993
  • DA-125, a new anthracycline antibiotic, showed antitumor activity against animal tumors and human tumors. Therefore we studied the cardiotoxic potential of DA-125 in hamsters and rats as a part of safety research, and compared it with that of doxorubicin(DXR). In acute cardiotoxicity test model used hamsters DA-125 was administered intravenously at a dose of 6, 9, 12 mg/kg, and DXR at 3 mg/kg was given. The electrocardiogram(ECG) of hamsters was recorded for 30 minutes after administration. The DA-125 caused slight ECG alterations at a dose of 6 mg/kg. At a dose of 12 mg/kg DA-125 induced moderate to remarkable changes in ECG like decrease of heart rate, widening of PR interval and 07 interval, and A-V block in 3 out of 5 animals. The severity of ECG alteration at 12 mg/kg of DA-125 was similar to that at 3mg/kg of DXR and these changes caused by DA-125 and DXR recovered within 10 minutes after injection. In chronic cardiotoxicity test model used rats, DA-125 was administered intravenously once a week for three weeks at a dose of 6, 9mg/kg and DXR was given at a dose of 6mg/kg. Electrocardiogram was recorded every week from the start of administration to 2 weeks after the last administration and the animals were sacrificed for histological heart examination at 1 week or 2 weeks after the last administration. DA-125 did not cause any abnormal changes in ECG and in histological heart examination due to administration, but DXR caused widening of ST segment, QRS complex, and QT interval from 1 week after administration and these changes were continued to necropsy. These alterations in ECG were accompanied by cardiac histological lesions such as vacuolation in myocardiac cells, interstitial edema and necrosis of myocytes. These results suggest that DA-125 is less cardiotoxic than DXR.

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Biological activities and single oral dose toxicity in rat of fermented Rhus verniciflua extract (발효 옻 추출물의 생리활성 및 단회 경구 투여 독성시험)

  • Choi, Myung-Jin;Lee, Seung-Jin;Jang, Seung-Hee;Reza, Md. Ahsanur;Hong, Joo-Heon;Jung, Hee-Kyoun;Park, Seung-Chun
    • Korean Journal of Veterinary Research
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    • v.50 no.3
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    • pp.187-195
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    • 2010
  • In this study, we investigated the biological activities such as anti-tumor, anti-oxidant and antiinflammatory activities as well as single oral dose toxicity of fermented Rhus verniciflua extract (FRVE). In order to examine anti-tumor activity of FRVE, the sarcoma 180 cells were treated with FRVE at various concentrations (0.03, 0.3, 3 and 30 mg/mL) in microtetrazolium (MTT) assay. In MTT assay, all the cells treated with FRVE at various concentrations have shown a significant difference compared with control (p < 0.05). In xanthine oxidase inhibition assay to examine the antioxidant activity, the xanthine oxidase inhibition rate of FRVE at 1.5 mg/mL and 15 mg/mL was $85{\pm}15.01%$ and $99{\pm}16.02%$, respectively. Nitric oxide production in RAW 264.7 cells showed that FRVE showed a significant anti-inflammation effect at 3 mg/mL (p < 0.05). In single oral dose toxicity study, no differences were observed between control and treated groups in clinical signs, body weight gains, feed and water consumptions. The results indicated that lethal dose 50 ($LD_{50}$) of FRVE was found to be higher than 5,000 mg/kg in this experiment. From the above results, we may suggest that FRVE might have useful as a material for functional food and/or animal pharmaceutics.

The Effect of Low Dose Bupivacaine on Epidural Morphine Analgesia for Postoperative Pian (경막외 몰핀 단독 투여와 국소마취제 혼주가 술후 진통 효과에 미치는 영향)

  • Ha, Han-Soo;Park, Yeong-Cheol;Kim, Hae-Kyoo;Baik, Seong-Wan;Chung, Kyoo-Sub
    • The Korean Journal of Pain
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    • v.7 no.2
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    • pp.188-192
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    • 1994
  • Recently, epidural morphine has been administrated to decrease patients' systemic stress responses such as: suffers, endocrine responses and impairment of pulmonary function, etc. Epidural morphine provided excellent analgesic effect, but incomplete sensory blockade as compared to epidural local anesthetics, which has sympathetic blockade effect and tachyphylaxis. Therefore, the authors surmised that low dose bupivacaine on low dose epidural morphine improved postoperative pain with greater sensory analgesia than epidural morphine alone. The effect of low dose bupivacaine on epidural morphine analgesia for postoperative pain was evaluated in seventy patients. They were physical status I-III by ASA classification. Patients were randomly divided into 2 groups and they were administrated morphine 2.5 mg only (group I), morphine 2.5 mg plus 0.125% bupivacaine (group II) through epidural catheter 1 hour before the end of the operation. During postoperative second days, their analgesic effects were evaluated by visual analogue scale (0-10). Side effects were also evaluated. The results were as follows, 1) On the day of the operation, VAS score showed significant differences between two groups (morphine group $3.20{\pm}0.16$, morphine plus bupivacaine group $2.77{\pm}0.08$; p < 0.05). 2) On the postoperative and second day, there were no statistical differences between the groups according to VAS score. 3) The incidence of pruritus, nausea, and vomiting were no differences in both groups. 4) None of the patients showed objective sedation or a low respiratory rate (< 10 bpm). We concluded that epidural administration of low dose bupivacaine on the epidural morphine analgesia was an effective method to decrease postoperative pain with little change in frequencies of side effects compared to epidural morphine alone.

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The Usefulness of Bolus of Radiation Therapy in Patients with Whole Breast Cancer

  • Min, Jung-Whan;Son, Jin-Hyun;Park, Hoon-Hee;Dong, Kyung-Rae
    • Korean Journal of Digital Imaging in Medicine
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    • v.13 no.3
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    • pp.99-103
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    • 2011
  • Radiation Therapy has been used in the treatment of breast cancer for over 80 years. Technically, it should include a part or all of such areas as chest wall or breast, axilla, internam mammary nodes and supraclavicular nodes. The purpose of this study is treated breast cancer patient to use 6 MV, 10 MV with bolus so that we observe changing of skin dose and evaluate those usefulness. Using woman's phantom, after CT simulate scanning, Through RTP system to make treatment plan, select three any place. And then, we measure that dose rate. After moving the phantom to linac, we put for TLD to three point same as RTP system which we put on the phantom. We exposed 6 MV, 10 MV with bolus and without so that it is measured dose by TLD device(4000 Harshaw). As a reult expose 6 MV,10 MV, it differences 10%, 15% according to bolus and withoout bolus where lateral point from RAO, LPO beam, other one is 20% where the furthest from both beams. To use bolus in the hospital is material to include closely part at skin among tissue of breast cancer. Acquired skin dose from RTP system is uncertainity. So it has to test another system likely TLD or other dosimetry system. Also exposed field of breast cancer is included inhomogeneity such as lung, bone and so on. Therefore it has to be accomplished a dose calculating of inhomogeneity part from treatment plan.

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Safety Pharmacology of CJ-11555 (CJ-11555의 안전성 약리실험)

  • 최재묵;이성학;김일환;박지은;김덕열;노현정;김택로;최광도;김영훈
    • Toxicological Research
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    • v.20 no.2
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    • pp.159-166
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    • 2004
  • Safety pharmacological properties of CJ-11555, an anti-cirrhotic agent, were investigated in experimental animals and in vitro test system. CJ-11555 had no effects on normal body temperature in rats, motor coordination, chemoshock induced by pentetrazol, electric shock induced by electric shocker and writhing syndromes in mice at dose levels of 100, 300 and 1,000 mg/kg. CJ-11555 inhibited intestinal activity and prolonged hexobarbital-induced sleeping time in mice at the dose level of 1,000 mg/kg. CJ-11555 affected on general activity and behaviour tests in SD rats, such as lacrimation, ptosis, piloerection, decreased body tone, abnormal dispersion within the cage, diarrhoea, red colored faeces, slight hypothermia and decreased grooming, at the dose level of 1,000 mg/kg in rats. CJ-11555 was effected on cardiovascular and respiratory system in anesthetized beagle dogs, such as tachycardia, increase of mean blood pressure and decrease of PR interval, decrease of respiratory rate and minute volume, at dose levels of 10 and 30 mg/kg. However, these effects were also observed in vehicle treated anesthetized beagle dogs. In in vitro experiments, CJ-11555 inhibited agonists (histamine, acetyl-choline or $BaCl_2$) induced contraction of isolated guinea-pig at the concentration of 30$\times$$10^6$ M. CJ-11555 was weekly inhibited hERG channel current at concentrations of 10 and 30$\times$$10^6$ M, and $IC_{50}$ was estimated to be higher than 30${\times}$$10^6$M. Based on these results, it was concluded that CJ-11555 affected on cardiovascular and respiratory system, general activity and behaviour and hexobarbital-induced sleeping time at the dose level of 1,000 mg/kg and contraction of the smooth muscle and hERG channel current at the concentration of 30$\times$$10^6$ M.