• 제목/요약/키워드: low doses

검색결과 744건 처리시간 0.031초

Effect of Platycodon Grandiflorum Aqueous Extract on Lipid Levels in Rats

  • Kim Jeong-Seon
    • Nutritional Sciences
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    • 제9권3호
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    • pp.167-172
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    • 2006
  • This study investigated the effects of Platycodon grandiflorum aqueous extract on lipid concentration of serum and liver in rats fed high cholesterol diet Male Sprague-Dawley rats were assigned to three groups (control, low dose of extract, high dose of extract) for four weeks. The serum total cholesterol concentration was significantly lower in the low and high doses of extract groups than in the control group. There was a significant decrease in the free cholesterol, cholesterol ester, LDL-cholesterol, and triglycerides concentrations in serum, and the total cholesterol and the triglycerides contentin liver in the low and high doses of extract groups compared to the control group. When the serum phospholipid concentration was compared among the groups, it was significantly lower in high dose of extract group than in control and low dose of extract group. It can be postulated that Platycodon grandiflorum aqueous extract may possess substantial hypolipidemic properties in rats.

악관절 단층촬영시의 두경부 주요 기관의 흡수선량 (Absorbed Doses in Organs of the Head and Neck from Conventional Temporomandibular Joint Tomography)

  • 조봉혜
    • 치과방사선
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    • 제29권2호
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    • pp.411-416
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    • 1999
  • Purpose : This study was done to evaluate the absorbed doses in organs of the head and neck for the conventional temporomandibular joint tomography. Materials and Methods : Dosimetry was performed with 32 LiF thermoluminescent dosimeters, which were placed in a tissue-equivalent phantom when the temporomandibular joint was examined by both lateral and frontal temporomandibular joint tomography. Results : For lateral tomography, parotid gland and preauricular area towards tube showed relatively high absorbed dose of 1056.9 μGy and 519.9 μGy respectively. For frontal tomography, the two largest absorbed doses were 259.2 μGy in orbit towards tube and 212.0 μGy in lens towards tube. Conclusion : Conventional temporomandibular joint tomography showed relatively low absorbed doses on critical organs. Thus, responsible use of it may not be limited.

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Methotrexate의 임상약동력학적 고찰 (Review on the Clinical Pharmacokinetics of Methotrexate)

  • 최경업
    • 한국임상약학회지
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    • 제1권1호
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    • pp.1-7
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    • 1991
  • Folates are involved in a variety of important biosynthesis by way of donating one carbon unit. Since folate metabolism was well understood a number of antifol have been developed. Among these antifols, aminopterin was first used in the treatment of childhood leukemia. However due to its toxicity and purity problems. it was immediately replaced by another antifols. methotrexate (MTX). MTX is shown to be active against various malignancies including leukemia breast cancer, osteogenic sarcoma, and head and neck cancer. Clinically, MTX therapy is divided into 3 categories. depeding on the dose administered; low-dose is defined as doses < $80\;mg/m^2$ intermediate-dose as doses $\geqq\;80\;mg/m^2$ and < $1000\;mg/m^2$ and high-dose as doses $\geqq\;1000\;mg/m^2$. Leucovorin should be administered to minimize MTX toxicities when MTX doses are greater than $80-100\;mg/m^2$. The clinical pharmacokinetics (ADME) of MTX is discussed in this text.

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자궁경부암 강내 방사선 조사장치에 의한 직장 및 방광의 피폭선량 평가 (Dose Distribution of Rectum and Bladder in Intracavitary Irradiation)

  • 추성실;오원용;서창옥;김귀언
    • Radiation Oncology Journal
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    • 제2권2호
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    • pp.261-270
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    • 1984
  • The intrauterine irradiation is essential to achieve adequate tumor dose to central tumor mass of uterine malignancy in radiotherapy. The complications of pelvic organ are known to be directly related to radiation dose and physical parameters. The simulation radiation and medical records of 203 patients who were treated with intrauterine irradiation from Feb. 1983 to Oct. 1983, were critically analized. The physical parameters to include distances between lateral walls of vaginal fornices, longitudinal and lateral angles of tandem applicator to the body axis, the distance from the external os of uterine cervix to the central axis of ovoids were measured for low dose rate irradiation system and high dose rate remote control afterloading system. The radiation doses and dose distributions within cervical area including interesting points and bladder, rectum, according to sources arrangement and location of applicator, were estimated with personal computer. Followings were summary of study results ; 1. In distances between lateral walls of vaginal fornices, the low dose rate system showed as $4\~7cm$ width and high dose rate system showed as $5\~6cm$. 2. In horizontal angulation of tandem to body axis, the low dose rate system revealed mid position$64.6\%$, left deviation $19.2\%$and right deviation $16.2\%$. 3. In longitudinal angulation of tandem to body axis, the mid position was $11.8\%$ and anterior angulation $88.2\%$ in low dose rate system but in high dose rate system, anterior angulation was $98.5\%$. 4. Down ward displacement of ovoids below external os was only $3\%$ in low dose rate system and $66.7\%$ in high dose rate system. 5. In radiation source arrangement, the most activities of tandem and ovoid were 35 by 30 in low dose rate system but 50 by 40 in high dose rate system. 6. In low and high dose rate system, the total doses an4 TDF were 50, 70 Gy and 141, 123, including 40 Gy external irradiation. 7. The doses and TDF in interesting points Co, B, were 93, 47 Gy and 230, 73 in high dose rate system but in low doss rate system, 123, 52 Gy and 262, 75 respectively. 8. Doses and TDF in bladder and rectum were 70, 68 Gy and 124, 120 in low dose rate system, but in high dose rate system, 58, 64 Gy 98, 110 respectively, and then grades of injuries in bladder and rectum were 25, $30\%$ and 18, $23\%$ respectively.

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Nutritional strategy of early amino acid administration in very low birth weight infants

  • Lee, Byong Sop
    • Clinical and Experimental Pediatrics
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    • 제58권3호
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    • pp.77-83
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    • 2015
  • Relative to a fetus of the same gestational age, very low birth weight (VLBW) infants are more likely to be underfed and to undergo growth restriction during their early hospital stay. The current trend towards "early and aggressive" nutritional strategies in VLBW infants aims to overcome the early nutritional deficiency and thereby boost postnatal catch-up growth, simultaneously improving long-term neurodevelopmental outcomes. Although the minimum starting amino acid (AA) dose to prevent negative nitrogen balance is well established, the upper limit and the rate of increase of early AA doses are controversial. Most randomized controlled trials show that early and high-dose (target, 3.5 to 4.9 g/kg/day) AA regimens, with or without high nonprotein calories, do not improve long-term growth and neurodevelopment. High-dose AA supplementation may lead to early metabolic disturbances and excessive or disproportionate plasma AA levels, particularly in infants of very low gestational age. Further large studies are needed to clarify the optimal strategy for early administration of parenteral AA doses in VLBW infants.

방사선(放射線) 조사(照射)에 의(依)한 맥아역가증대(麥芽力價增大)에 관(關)한 연구(硏究) (Effects of Gamma-irradiation on Enzyme Activities of Green Malt)

  • 김병묵;김형수
    • Applied Biological Chemistry
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    • 제11권
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    • pp.131-136
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    • 1969
  • 저선량(低線量) 방사선(放射線)의 생물학적(生物學的) 촉진효과(促進效果) (possitive effect)는 이미 주지(周知)된 사실(事實)인 바 맥아(麥芽)의 역가증대(力價增大)에 대(對)한 그 응용성(應用性) 여하(如何)를 검토(檢討)하기 위(爲)하여 대맥종자(大麥種子)에 10, 100, 1000, 10000 rads의 ${\gamma}$선(線)을 조사(照射)하고 맥아(麥芽)를 만들어 기중(其中)의 몇몇 효소(酵素)의 활성(活性)을 측정(測定)한 결과(結果) 다음과 같은 성적(成績)을 얻었다. 1. 표준구(標準區)에 비(比)해 조사구(照射區)의 생체중(生體重)은 1,000rads 이하의 저선량구(低線量區)에서는 증가(增加)되었으나 10,000rads의 고선량구(高線量區)에서는 감소(減少)되었다. 2. ${\alpha}$-amylase activity 및 당화력(糖化力)은 전조사구(全照射區)에서 증대(增大)되었으며 특(特)히 100rads 구(區)에서 최대치(最大値)를 나타내었다. 증대효과(增大效果)는 ${\alpha}$-amylase activity의 경우 $26{\sim}69%$ 당화력(糖化力)의 경우 $87{\sim}178%$이었다. 3. pretense activity는 1,000rads이하의 저선량구(低線量區)에서는 거의 변화(變化)가 없고 10,000rads의 고선량구(高線量區)에서는 현저히 감소(減少)되었다. 4. 생맥아중(生麥芽中)의 환원당(還元糖) 함량(含量)은 전조사구(全照射區)에서 감소(減少) 되었으며 특(特)히 100, 1,000 rads 구(區)에서 더욱 감소(減少)되었다. 5. 생맥아중(生麥芽中)의 soluble protein 함량(含量)은 전조사구(全照射區)에서 증가(增加)되었으며 특(待)히 100rads 구(區)에서 가장 증가(增加)되었다.

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Comparison of Three Dimensional Conformal Radiation Therapy, Intensity Modulated Radiation Therapy and Volumetric Modulated Arc Therapy for Low Radiation Exposure of Normal Tissue in Patients with Prostate Cancer

  • Cakir, Aydin;Akgun, Zuleyha;Fayda, Merdan;Agaoglu, Fulya
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권8호
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    • pp.3365-3370
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    • 2015
  • Radiotherapy has an important role in the treatment of prostate cancer. Three-dimensional conformal radiation therapy (3D-CRT), intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) techniques are all applied for this purpose. However, the risk of secondary radiation-induced bladder cancer is significantly elevated in irradiated patients compared surgery-only or watchful waiting groups. There are also reports of risk of secondary cancer with low doses to normal tissues. This study was designed to compare received volumes of low doses among 3D-CRT, IMRT and VMAT techniques for prostate patients. Ten prostate cancer patients were selected retrospectively for this planning study. Treatment plans were generated using 3D-CRT, IMRT and VMAT techniques. Conformity index (CI), homogenity index (HI), receiving 5 Gy of the volume (V5%), receiving 2 Gy of the volume (V2%), receiving 1 Gy of the volume (V1%) and monitor units (MUs) were compared. This study confirms that VMAT has slightly better CI while thev olume of low doses was higher. VMAT had lower MUs than IMRT. 3D-CRT had the lowest MU, CI and HI. If target coverage and normal tissue sparing are comparable between different treatment techniques, the risk of second malignancy should be a important factor in the selection of treatment.

Dose-dependent UV Stabilization of p53 in Cultured Human Cells Undergoing Apoptosis Is Mediated by Poly(ADP-ribosyl)ation

  • Won, Jungyeon;Chung, So Young;Kim, Seung Beom;Byun, Boo Hyeong;Yoon, Yoo Sik;Joe, Cheol O.
    • Molecules and Cells
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    • 제21권2호
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    • pp.218-223
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    • 2006
  • The effect of poly(ADP-ribosyl)ation on the stability of p53 in SK-HEP1 cells treated with UV light was examined. Intracellular levels of p53 increased in cells treated with a low dose of UV light ($20J/m^2$), whereas they increased but then declined after a higher dose of UV ($100J/m^2$). Intracellular levels of p53 in the UV treated SK-HEP1 cells were dependent on the UV dose. Use of proteasome inhibitors revealed that p53 is degraded by proteasomal proteolysis after high doses of UV light. We present evidence that, at low doses, poly(ADP-ribose)polymerase (PARP) poly(ADP-ribosyl) ates p53 and protects it from proteasomal degradation before caspase-3 is activated, whereas at high doses the cells undergo UV induced apoptosis and PARP is cleaved by caspase-3 before it can protect p53 from degradation. Destabilization of p53 by cleavage of PARP may be important in cell fate decision favoring apoptosis.

방사선(放射線)을 이용(利用)한 양파저장(貯藏)에 관(關)한 연구(硏究) (1) (Sudies on the Storage of Onions by Radiation (1))

  • 박노풍;최언호;변광의
    • 한국식품과학회지
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    • 제4권2호
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    • pp.84-89
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    • 1972
  • An experiment was carried out to investigate the optimum doses of gamma-irradiation for sprouting inhibition of onion bulbs with irradiation time and storage conditions. The results. obtained are as follows: 1) The irradiation doses of 5, 7 and 10 krad, respectively, at 11, 32 and 66 days after harvest were sufficient to inhibit subsequent sprout of onion bulbs obtained from Nampyeong district. When they were irradiated at 96 day after harvest, however, there was little sprout-inhibition by 15 krad. In case of onion bulbs obtained from Changnyeong district, sprout was inhibited by doses of 8 and 12 krad respectively, at 51 and 89 days after harvest. 2) Low-temperature storage after irradiation was not effective in sprout-inhibition of onion bulbs. Onion bulbs stored at low temperature of $5^{\circ}C$ rather showed higher sprouting rate as compared with that of room temperature. 3) Rot increased in irradiated lot and at room temperature, and spores of Aspergillus sp. were little germinated at a level of 100 krad. 4) The respiratory rate of irradiated onion bulbs was higher immediately after irradiation but lower one week after irradiation than control. Respiratory quotient of tissues seems to be little affected by gamma-irradiation.

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Successful engraftment after infusion of multiple low doses of CD34+ cells from a poorly matched sibling donor in a patient with severe aplastic anemia

  • Kum, Chang Dae;Lee, Mi Jin;Park, Jun Eun
    • Journal of Yeungnam Medical Science
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    • 제36권2호
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    • pp.148-151
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    • 2019
  • The dose of CD34+ cells is known to influence the outcome of allogeneic peripheral blood stem cell (PBSC) and/or T-cell-depleted transplantation. A previous study proposed that $2{\times}10^6\;CD34+\;cells/kg$ is the ideal minimum dose for allogeneic transplantation, although lower doses did not preclude successful therapy. In the case we present here, CD34+ cells were collected from a matched sibling donor on the day of allogeneic hematopoietic stem cell transplantation; however, the number of cells was not sufficient for transplantation. Consequently, PBSCs were collected three additional times and were infused along with cord blood cells from the donor that were cryopreserved at birth. The cumulative dose of total nuclear cells and CD34+ cells was $15.9{\times}10^8\;cells/kg$ and $0.95{\times}10^6\;cells/kg$, respectively. White blood cells from this patient were engrafted on day 12. In summary, we report successful engraftment after infusion of multiple low doses of CD34+ cells in a patient with severe aplastic anemia.