• Title/Summary/Keyword: low dose effect

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Evaluated Absorbed Dose According to Prescribed Dose and Therapeutic Technique in Radiation Therapy (방사선치료 시 처방선량과 치료기법에 따른 흡수선량 평가)

  • Lee, Deuk-hee;Park, Eun-tae;Kim, Jung-hoon;Im, In-chul
    • Journal of the Korean Society of Radiology
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    • v.10 no.6
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    • pp.469-476
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    • 2016
  • In this study, evaluated absorbed dose of moving target using PLD according to prescribed dose and therapeutic technique. First, result of MCNPX when target was deviated from exposure field was reduced dose in proportion to distance. According to prescribed dose, absorbed dose of 3D CRT was better than IMRT in low dose and IMRT was more better in high dose. Absorbed dose of 3D CRT was highest according to therapeutic technique. Therefore, 3D CRT was technique of irradiated highest dose to moving target. But, considered protective effect of normal tissue and patient condition that therapeutic technique was selected to maximized treatment efficiency.

Changes in Expression of Connexin Isoforms in the Caudal Epididymis of Adult Sprague-Dawley Rats exposed to Estradiol Benzoate or Flutamide at the Neonatal Age

  • Lee, Ki-Ho
    • Development and Reproduction
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    • v.20 no.3
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    • pp.237-245
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    • 2016
  • Direct communication between neighboring cells via gap junction in tissue is important for maintenance and regulation of its physiological functions. Each epididymal region has different composition of cell types. It is well recognized that the epididymis is a steroid hormone-responsive tissue. The present study was designed to determine the effect of estradiol benzoate (EB) or flutamide exposured at the early postnatal age on the expression of connexin (Cx) isoforms in the caudal epididymis. The EB or flutamide was subcutaneously administrated to male Spragure Dawley rat at 7 days of age, and expressional changes of Cx isoforms in the adult corpus epididymis were determined by quantitative real-time PCR. The treatment of low-dose EB resulted in decreases of Cx30.3, Cx31.1, Cx37, and Cx45 expression but caused an increase of Cx32 expression. Exposure to high-dose EB led into expressional increases of Cx31, Cx31.1, Cx32, Cx40, and Cx43, even though a decrease of Cx37 expression was found with a high-dose EB treatment. A low-dose flutamide induced increases of Cx31, Cx31.1, Cx32, and Cx43 expression but a decrease of Cx37 expression. Expression of most Cx genes were significantly increased by a high-dose flutamide, while no expressional change of Cx26 and Cx40 was detected by a high-dose flutamide. These results indicate that expression of Cx isoforms in the caudal epididymis is altered by exposure to steroidal compounds at the prepubertal age. It is suggested that a contact with environmental exogenous materials during the early postnatal period would lead to alteration of epididymal functions at the adult.

Increasing injection frequency enhances the survival of injected bone marrow derived mesenchymal stem cells in a critical limb ischemia animal model

  • Kang, Woong Chol;Oh, Pyung Chun;Lee, Kyounghoon;Ahn, Taehoon;Byun, Kyunghee
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.6
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    • pp.657-667
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    • 2016
  • Critical limb ischemia (CLI) is one of the most severe forms of peripheral artery diseases, but current treatment strategies do not guarantee complete recovery of vascular blood flow or reduce the risk of mortality. Recently, human bone marrow derived mesenchymal stem cells (MSCs) have been reported to have a paracrine influence on angiogenesis in several ischemic diseases. However, little evidence is available regarding optimal cell doses and injection frequencies. Thus, the authors undertook this study to investigate the effects of cell dose and injection frequency on cell survival and paracrine effects. MSCs were injected at $10^6$ or $10^5$ per injection (high and low doses) either once (single injection) or once in two consecutive weeks (double injection) into ischemic legs. Mice were sacrificed 4 weeks after first injection. Angiogenic effects were confirmed in vitro and in vivo, and M2 macrophage infiltration into ischemic tissues and rates of limb salvage were documented. MSCs were found to induce angiogenesis through a paracrine effect in vitro, and were found to survive in ischemic muscle for up to 4 weeks dependent on cell dose and injection frequency. In addition, double high dose and low dose of MSC injections increased vessel formation, and decreased fibrosis volumes and apoptotic cell numbers, whereas a single high dose did not. Our results showed MSCs protect against ischemic injury in a paracrine manner, and suggest that increasing injection frequency is more important than MSC dosage for the treatment CLI.

Effect of dietary protein level on bone metabolism of young and aged rats (식이 단백질 수준이 어린쥐와 나이든 쥐의 골격의 대사에 미치는 영향)

  • 조미숙
    • Journal of Nutrition and Health
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    • v.22 no.6
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    • pp.497-506
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    • 1989
  • To investigate the effect of levels of dietary protein and age on bone metabolism 40% and 5% casein were fed to the rats of 2 & 13 months of age for 12 weeks. High protein groups showed higher bone weight and Ca content than low protein groups and urinary Ca loss was increased in high protein groups but the difference disappeared gradually. A significant increase in urinary hydroxyproline excretion was noted in high protein groups of both age. Another short term study was undertaken to study if the above effect was related with renal function or PTH. Extremely high and low protein diets(60%, 6%) were fed to the rats of different ages(6wks, 6mos.) for 2 weeks, Urinary Ca excretion was significantly increased in high protein groups of young and aged rats and GFR was increased as well. There was no difference in serum iPTH levels between low and high protein groups, but it was elevated in aged rats. Alkaline phosphatase activity was higher in young rats, reflecting faster bone formation. The observed hypercalciuria in high protein groups, especially in aged rats, seems to be related to higher GFR, and PTH dose not appear to be a major mediator.

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Effects of low dose gamma irradiation on the germination and physiological activity of old red pepper ( Capsicum annuum L.) seed (묵은 고추종자의 발아와 생리활성에 미치는 저선량 방사선조사 효과)

  • Kim, Jae-Sung;Back, Myung-Hwa;Lee, Hae-Youn;Lee, Young-Keun
    • Journal of Radiation Protection and Research
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    • v.26 no.4
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    • pp.409-415
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    • 2001
  • To observe the stimulating effects of low dose gamma radiation on the germination and physiological activity of germinating seeds of old red pepper (Capsicum annuum L. cv Jokwang and cv. Hongkwang), seeds were irradiated at the dose of $2{\sim}50 Gy$. The germination rate of irradiation group was higher than that of the control. Especially it was highest at the early stage of induction. The germination rate at 7 days after sowing in Jokwang and Hongkwang cultivar was high as 74% and 11% at 4 Gy and 8 Gy irradiation group, respectively. The seedling height of Jokwang cultivar was noticeably high at 4 Gy irradiation group and that of Hongkwang cultivar at 8 Gy irradiation group. The protein contents of seedlings from seeds irradiated with low dose gamma radiation of Jokwang cultivar increased at the late stage of induction and that of Hongkwang cultivar at the early stage of induction. Catalase and peroxidase activities of seedlings from seeds irradiated with low dose gamma radiation of Jokwang cultivar increased at 4 Gy irradiation group and that of Hongkwang cultivar at 8 Gy irradiation group.

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Effect of Korean Red Ginseng Extract on Blood Circulation in Healthy Volunteers: A Randomized, Double-Blind, Placebo-Controlled Trial (건강한 지원자에서 홍삼농축액의 혈행 개선 효과: 무작위, 이중맹검, 위약-대조 시험)

  • Shin, Kyeong-Seob;Lee, Jung-Jin;Kim, Yeong-Il;Yu, Ji-Yeon;Park, Eun-Seok;Im, Ji-Hyun;You, Soon-Hyang;Oh, Ki-Wan;Lee, Myung-Koo;Wee, Jae-Joon;Kim, Young-Sook;Yun, Yeo-Pyo
    • Journal of Ginseng Research
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    • v.31 no.2
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    • pp.109-116
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    • 2007
  • Korean red ginseng has broad efficacious effects against hypertension, diabetes, nociception, and cancer, and it counteracts weakness. It has been reported that Korean red ginseng is able to normalize blood pressure, improve cholesterol and lower blood glucose levels. We have recently reported that Korean red ginseng extract (KRGE) significantly prevented rat carotid arterial thrombosis in vivo, and inhibited platelet aggregation ex vivo and in vitro in a dose-dependent manner. The purpose of this study was to examine the effects of KRGE on blood circulation in human by measuring ex vivo platelet aggregation, plasma coagulation and serum lipid profiles in healthy volunteers. Subjects were randomly divided into three groups (placebo-group, KRGE-low dose group, KRGE-high dose group). Administration of KRGE to subjects significantly inhibited ADP-induced platelet aggregations both in KRGE-low dose group from $72.79{\pm}20.53$ to $62.00{\pm}23.06%$ (p=0.0009), and in KRGE-high dose group from $75.14{\pm}21.86$ to $64.52{\pm}24.72%$ (p=0.0039), respectively. Administration of KRGE to subjects also significantly inhibited collagen-induced platelet aggregations both in KRGE-low dose group from $85.52{\pm}12.57$ to $79.62{\pm}20.47%$ (p=0.0916), and in KRGE-high dose group from $80.24{\pm}18.11$ to $70.31{\pm}25.93%$ (p=0.0565), respectively. Whereas, KRGE has no significant effects on coagulation system, such as prothrombin time (PT) and activated partial thromboplastin time (APTT), and serum lipid profiles, such as total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol and triglyceride. KRGE also has no significant effects on hematological and serum biochemical profiles. These results suggest that KRGE has a potential to improve blood circulation through antiplatelet activity in human, and KRGE intake may be beneficial for the individuals with high risks of thrombotic and cardiovascular diseases.

A Study on the Comparative Analysis of Images and Doses According to Tube Orientation During Anterior-Posterior Axial Projection Examination of the Skull (머리뼈 전-후 축 방향검사 시 Tube 방향설정에 따른 표면선량과 영상분석에 관한 연구)

  • Jeong, Sung-Hun;Yoo, Je-hyeon;Lim, Cheong-Hwan
    • Journal of radiological science and technology
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    • v.44 no.4
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    • pp.301-306
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    • 2021
  • The skull has peripheral organs such as the crystalline lens and thyroid gland, which are highly radiosensitive, but the examination is performed without considering the uneven dose distribution due to the heel effect at the time of the current Skull Town's examination. However, no studies have been conducted on the exposure dose of surrounding organ tissues due to the difference in image density due to the heel effect and the non-uniformity of the dose. Using the cathode (-) and anode (+) set on the Tube to measure the scattered radiation along the Tube direction as a guide, change 30° and 37° in the cathode direction and 30° and 37° in the anode direction. It was given and investigated 5 times to obtain scattered radiation. image measurements were SNR, PSNR, RMSE, and MAE. Measurement results Measurement results of surrounding organ doses when the Tube direction was 30° and 37° The dose was low when the direction was cathodic in all organs (p<0.000). Both cathodes were higher in the image measurements(p<0.04). Continuous research may be needed for diagnostically valuable imaging and minimization of patient exposure dose.

Effect of high-dose ginsenoside complex (UG0712) supplementation on physical performance of healthy adults during a 12-week supervised exercise program: A randomized placebo-controlled clinical trial

  • Lee, Eon Sook;Yang, Yun Jun;Lee, Jun Hyung;Yoon, Yeong Sook
    • Journal of Ginseng Research
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    • v.42 no.2
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    • pp.192-198
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    • 2018
  • Background: Ginseng has been used as an ergogenic agent, although evidence for its effectiveness is weak. A randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate the effect of a ginsenoside complex (UG0712) on changes in exercise performance. Methods: Sedentary individuals (n = 117) were randomly assigned into one of three groups: low-dose ginsenoside supplementation (100 mg/d, n = 39), high-dose ginsenoside supplementation (500 mg/d, n = 39), or a placebo group (500 mg/d, n = 39). All participants underwent a supervised 12-wk aerobic and resistance exercise training course. To assess the effects of supplementation on physical performance, maximal oxygen consumption ($VO_2max$), anaerobic threshold (AT), lactic acid, and muscle strength of the dominant knee were measured at baseline, every visit, and after the training program. Results: Both ginsenoside groups showed significant increases in $VO_2max$ and muscular strength during exercise training. There were no definite changes in AT and lactic acid levels over time. After exercise training, there were definite differences in the $VO_2max$ (28.64.9 to $33.7{\pm}4.9ml/kg/min$ in high-dose group vs. $30.4{\pm}6.7$ to $32.8{\pm}6.6ml/kg/min$ in placebo, p = 0.029) and AT ($19.3{\pm}4.2$ to $20.9{\pm}3.5ml/kg/min$ in high-dose group vs. $20.0{\pm}5.1$ to $20.0{\pm}4.9ml/kg/min$ in placebo, p = 0.038) between the high-dose ginsenoside and placebo groups. However, there was no difference in $VO_2max$ between the low-dose ginsenoside and placebo groups (p = 0.254). There were no differences in muscular strength during exercise training among the three groups. Conclusion: High-dose ginsenoside supplementation (UG0712) augmented the improvement of aerobic capacity by exercise training.

Feasibility of normal tissue dose reduction in radiotherapy using low strength magnetic field

  • Jung, Nuri Hyun;Shin, Youngseob;Jung, In-Hye;Kwak, Jungwon
    • Radiation Oncology Journal
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    • v.33 no.3
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    • pp.226-232
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    • 2015
  • Purpose: Toxicity of mucosa is one of the major concerns of radiotherapy (RT), when a target tumor is located near a mucosal lined organ. Energy of photon RT is transferred primarily by secondary electrons. If these secondary electrons could be removed in an internal cavity of mucosal lined organ, the mucosa will be spared without compromising the target tumor dose. The purpose of this study was to present a RT dose reduction in near target inner-surface (NTIS) of internal cavity, using Lorentz force of magnetic field. Materials and Methods: Tissue equivalent phantoms, composed with a cylinder shaped internal cavity, and adjacent a target tumor part, were developed. The phantoms were irradiated using 6 MV photon beam, with or without 0.3 T of perpendicular magnetic field. Two experimental models were developed: single beam model (SBM) to analyze central axis dose distributions and multiple beam model (MBM) to simulate a clinical case of prostate cancer with rectum. RT dose of NTIS of internal cavity and target tumor area (TTA) were measured. Results: With magnetic field applied, bending effect of dose distribution was visualized. The depth dose distribution of SBM showed 28.1% dose reduction of NTIS and little difference in dose of TTA with magnetic field. In MBM, cross-sectional dose of NTIS was reduced by 33.1% with magnetic field, while TTA dose were the same, irrespective of magnetic field. Conclusion: RT dose of mucosal lined organ, located near treatment target, could be modulated by perpendicular magnetic field.

Protective Effect of Combinational Antidotes Composed of Physostigmine and Procyclidine Against Nerve-agent Poisoning

  • Kim, Yun-Bae;Cheon, Ki-Cheol;Hur, Gyeung-Haeng;Phi, Taek-San;Kim, Jee-Cheon;Deasik Hang
    • Toxicological Research
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    • v.16 no.3
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    • pp.195-200
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    • 2000
  • Antidotal efficacy of physostigmine plus procyclidine, the combinational prophylactics for organophosphate poisoning, was evaluated in rats and guinea pigs. To assess the dose-response relation-ship in rats, various doses (0.3-6.0mg/kg) of procyclidine in combination with a fixed dose (0.1mg/kg) of physostigmine were pretreated subcutaneously 30 min prior to subcutaneous exposure to nerve-agents. Physostigmine alone exerted protection ratios of 2.44, 1.20, 1.50, 1.50 and 2.20 folds for tabun, sarin, soman, cyclosarin and V-agent, respectively. Interestingly, coadmnistration of procyclidine with physostigmine exhibited remarkable synergistic effects in a dose-dependent manner, leading to 4.00~8.00 folds for tabun, 2.15-8.50 folds for sarin, 1.92~507 folds for so man, 2.15~2.90 folds for cyclosarin, and 2.71~10.50 folds for V-agent. On the contrary, a low effect (l.65 fold) was achieved with the traditional antidotes atropine (17.4 mg/kg) plus 2-pralidoxime (30 mg/kg) treated immediately after soman poisoning. Noteworthy, the combinational prophylactics markedly potentiated the effect of atropine plus 2-pralidoxime to 6.13 and 12.27 folds with 1.0 and 3.0 mg/kg of procyclidine, respectively, against soman poisoning. In guinea pigs, the physostigmine plus procyclidine prophylactics exerted protective effects of 3.00~4.70 folds against soman intoxcation, which were much higher at low doses (0.3~1.0 mg/kg) of procyclidine than those in rats. Taken together, it is proposed that the combinational prophylactics composed oj physostigmine and procyclidine could be a promising antidote regimen for the poisoning with organophosphates possessing diverse properties.

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