• 제목/요약/키워드: Dose-response

검색결과 2,332건 처리시간 0.027초

X-band EPR dosimetry using minimum mass of tooth enamel for use in radiological accidents

  • Jae Seok Kim;Byeong Ryong Park;Han Sung Kim;In Mo Eo;Jaeryong Yoo;Won Il Jang;Minsu Cho;HyoJin Kim;Yong Kyun Kim
    • Nuclear Engineering and Technology
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    • 제56권1호
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    • pp.123-131
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    • 2024
  • Electron paramagnetic resonance (EPR) dosimetry for a tooth from an individual exposed is well known as retrospective dosimetry in radiological accidents. A major constraint of the conventional X-band tooth-EPR dosimetry is the necessity to extract the tooth of the exposed patient for dose assessment. In this study, to conduct the dose assessments of exposed patients through part-extraction of tooth enamel, the minimum detectable dose (MDD) of the tooth enamel was evaluated based on the amount of mass. Further, a field test was conducted via intercomparison using various dose assessment methods to verify the feasibility of X-band tooth-EPR dosimetry using the minimum mass of tooth enamel. The intercomparison results demonstrated that effective dose determination via X-band tooth-EPR dosimetry is reliable. Consequently, it was determined that the minimum mass of tooth enamel required to evaluate an absorbed dose above 0.5 Gy is 15 mg. Thus, EPR dosimetry using 15 mg of tooth enamel can be applied in the triage and initial medical response stages for patients exposed during radiological accidents. This approach represents an advancement in managing radiological accidents by offering a more efficient and less invasive method of dose assessment.

카드뮴투여가 Balb/c 마우스의 면역반응에 미치는 영향 (Effect of Cadmium Chloride on the Immune Responses in Balb/c Mouse)

  • 염정호;강현철;고대하
    • 한국환경보건학회지
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    • 제21권3호
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    • pp.16-22
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    • 1995
  • This study was designed to investigate the antibody production to sheep red blood cells(SRBC) and proliferation of mitogen-stimulated spleen cells in Balb/c mice which received cadmium chloride. The mice were divided into three independent groups which were one control and two experimental groups by the cadmium treatment or not. No specific treatment was done for the control group. One of two experimental groups, which is called 'pre-treatment group' in this paper, was subcutaneously injected with low dose of cadmium chloride(0.5 mg/kg/day) for 5 consecutive days before the primary SRBC immunization. The other called 'non-pretreatment group' was only pretreated with normal saline. Both experimental groups were intraperitoneally injected with high dose of cadmium chloride(5 mg/kg) 8 hours before the primary immunization. Mice were intraperitoneally immunized twice with 2% SRBC suspension containing $10^8$ cells. The results obtained were as follows, 1. The PFG responses to SRBC were significantly increased in two experimental groups, cadmium pretreatment and non-pretreatment compared with that of control group(p<0.05). 2. The total antibody titers to SRBC in cadmium treated groups were similar to that of control group, but titers of IgG antibody were significantly elevated(p<0.01). 3. The proliferation response of spleen lymphocytes to various mitogens was suppressed in proportion to the concentration of cadmium and the degree of cadmium accumulation in liver was increased in the cadmium treated groups. These results suggest that cadmium chloride could affect on mouse immune response, especially its cell mediated immune response could be decreased while its humoral immune response could be increased, which may not be influenced by the administration methods or pretreatment of cadmium to mouse.

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Effect of zinc on the immune response and production performance of broilers: a meta-analysis

  • Hidayat, Cecep;Sumiati, Sumiati;Jayanegara, Anuraga;Wina, Elizabeth
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권3호
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    • pp.465-479
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    • 2020
  • Objective: This study performed a meta-analysis of published trials to determine the effects of zinc on the immune response and production performance of broilers. Methods: A database was built from published literature regarding the addition of zinc forms or doses and their relation to the immune response and production performance of broilers. Different doses or forms of zinc were identified in the database. The recorded parameters were related to the immune response and production performance. The database contained a total of 323 data points from 41 studies that met the criteria. Then, the data were processed for a meta-analysis using a mixed model methodology. The doses or different forms of zinc were considered fixed effects, different studies were treated as random effects, and p-values were used as the model statistics. Results: An increase in zinc dose increased (p<0.05) pancreas metallothionein (MT) and zinc concentrations in the plasma, tibia and meat, all in quadratic patterns, but linearly decreased (p<0.05) the heterophil/lymphocyte (H/L) ratio. Regarding the different zinc forms, both inorganic and organic zinc increased (p<0.05) the zinc concentrations in the plasma and tibia, the calcium and phosphorus contents in the tibia, and the antioxidant activity of superoxide dismutase in meat as compared to control. An increase in zinc dose increased average daily gain (ADG) and decreased feed conversion ratio (FCR) following a quadratic pattern (p<0.05). Inorganic and organic zinc decreased (p<0.05) FCR and H/L ratio than that of control, but these two forms were similar for these parameters. Conclusion: Zinc addition has a positive impact on immunity and broiler production. Zinc can suppress stress and inhibit the occurrence of lipid peroxidation in broilers, and it can also improve ADG, FCR, and the quality of broiler carcasses.

Application of Response Surface Method as an Experimental Design to Optimize Coagulation Tests

  • Trinh, Thuy Khanh;Kang, Lim-Seok
    • Environmental Engineering Research
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    • 제15권2호
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    • pp.63-70
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    • 2010
  • In this study, the response surface method and experimental design were applied as an alternative to conventional methods for the optimization of coagulation tests. A central composite design, with 4 axial points, 4 factorial points and 5 replicates at the center point were used to build a model for predicting and optimizing the coagulation process. Mathematical model equations were derived by computer simulation programming with a least squares method using the Minitab 15 software. In these equations, the removal efficiencies of turbidity and total organic carbon (TOC) were expressed as second-order functions of two factors, such as alum dose and coagulation pH. Statistical checks (ANOVA table, $R^2$ and $R^2_{adj}$ value, model lack of fit test, and p value) indicated that the model was adequate for representing the experimental data. The p values showed that the quadratic effects of alum dose and coagulation pH were highly significant. In other words, these two factors had an important impact on the turbidity and TOC of treated water. To gain a better understanding of the two variables for optimal coagulation performance, the model was presented as both 3-D response surface and 2-D contour graphs. As a compromise for the simultaneously removal of maximum amounts of 92.5% turbidity and 39.5% TOC, the optimum conditions were found with 44 mg/L alum at pH 7.6. The predicted response from the model showed close agreement with the experimental data ($R^2$ values of 90.63% and 91.43% for turbidity removal and TOC removal, respectively), which demonstrates the effectiveness of this approach in achieving good predictions, while minimizing the number of experiments required.

신생아에서의 부신기능 평가와 질환 (Evaluation of function and disorders of the adrenal gland in neonates)

  • 황일태
    • Clinical and Experimental Pediatrics
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    • 제50권3호
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    • pp.236-240
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    • 2007
  • Majority of sick full term newborns have adequate adrenal cortical function in response to stress. Acutely ill neonates with a basal cortisol level less than $15{\mu}g/dL$ (414 nmol/L) suggest adrenal insufficiency and require function testing of adrenal function. In premature infant, immaturity of hypothalamic-pituitary adrenal axis (HPA axis), may limit the ability to increase cortisol production in response to stress. The response to low dose ACTH and CRH appears to be useful as an additional test of adrenal function. CRH stimulation has been used increasingly in neonates. The ACTH and CRH stimulated cortisol response of more than $17{\mu}g/dL$ (469 nmol/L) indicates a normal response.

Debrisoquine이 노르에피네프린 및 티라민의 승압효과에 미치는 영향 (Influence of Debrisoquine Pressor Actions of Norepinephrine and Tyramine in Rabbits)

  • 고석태;김해석;이상현
    • 약학회지
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    • 제30권3호
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    • pp.111-120
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    • 1986
  • The influence of debrisoquine on pressor actions of norepinephrine (NE) and tyramine (TR) was investigated in rabbits. Debrisquine(D), in the doses of 1.0, 3.0 and 6.0.mu.g/kg, i.v. potentiated significantly the pressor actions of NE and TR, except the action of TR in the dose of 1.0mg/kg of debrisoquine. NE response potentiated by debrisoquine was not affected by tranylcypromine, a MAO inhabiter, or desipramine, a NE uptake blocking agent, but augmented by reserpine, a NE depleting agent, or bethanidine, a sympathetic neuronal blocking agent. NE response potentiated by tranylcypromine or desipramine was augmented by debrisoquine, while NE response potentiated by reserine or bethanidine was not affected by debrisoquine. TR response potentiated by debrisoquine was weakened by tranylcypromine, desipramine or reserpine, and not affected by bethanidine. TR response in rabbit pretreated with tranylcypromine, desipramine or reserpine was augmented by debrisoquine, but in rabbit pretreated with bethanidine was not affected by debrisoquine.

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바닥분수에서 물놀이를 하는 아동들의 Legionella균 감염 위해도 분석 (Quantitative Microbial Risk Assessment on Legionella Infection in Children Playing in Interactive Fountains)

  • 이인섭;조영근
    • 미생물학회지
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    • 제49권4호
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    • pp.360-368
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    • 2013
  • 최근 국내의 각종 시설들에서 경관과 여름철 물놀이를 위한 바닥분수 설치가 선호되어, 그 수가 연간 50% 이상 급증하고 있다. 본 연구는, 정량적 미생물학적 위해성 평가 방법으로, 아동이 바닥분수에서 물놀이를 하는 동안 Legionella spp.에 의한 감염 위해도가 어느 정도인지 정량 하였다. 용수 중 Legionella균의 농도를 $10^{-1}-10^6$ CFU/L로 상정하고, 공기 중으로 에어로졸과 함께 비산하게 되는 Legionella균의 농도와 노출시간, 호흡률의 분포, 폐까지 도달하는 에어로졸의 비율을 곱하여 아동들의 노출량을 산정하고, Legionella pneumophila의 위해도를 도출하는 것으로 알려진 지수함수 모델에 따라, 감염 위해도로 변환하였다. 최고 위험군은 뛰어다니면서 물놀이를 하는 신체가 큰, 혹은 연령이 높은 아동이었으며, 이들이 $10^4$ CFU/L 이상의 Legionella균이 존재하는 분수 용수를 1회 이상 이용 시 0.05 이상의 위해도가 발생하였다. 이 결과에 따르면, $10^3$ CFU/L 미만의 Legionella균 농도를 공중이용시설의 모든 배관용수에 대하여 허용하는 현행 질병관리본부의 레지오넬라증 관리지침은 타당한 것으로 판정된다. 그러나, 이 기준은 건강한 성인 대상으로는 적합하나 아동의 면역력이 낮은 점을 감안하지 않았으므로, 아동에게 적합한 감염위해도 모델을 연구하여, 보다 철저한 관리 기준을 적용할 필요성이 있다.

심방세동 환자에서 Warfarin 반응성에 이뇨제가 미치는 영향 (Effects of Diuretics on Warfarin Responses in Patients with Atrial Fibrillation)

  • 박희주;나현오;곽혜선
    • 한국임상약학회지
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    • 제23권2호
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    • pp.151-157
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    • 2013
  • Purpose: Warfarin is the most widely used anticoagulant drug for preventing cardiovascular diseases after ischemic stroke and thromboembolism related to atrial fibrillation, artificial heart valves, deep vein thrombosis, and pulmonary embolism. Warfarin is commonly used in combination with other drugs such as diuretics in order to treat the comorbidity. Although several warfarin-diuretics interactions have been reported, the results are conflicting. Therefore, the initial aim of this study was to identify the effects of diuretics on the warfarin response in patients with atrial fibrillation. Methods: One hundred forty six patients with atrial fibrillation who were on anticoagulation therapy with warfarin and maintained INR levels of 2-3 for three consecutive times were followed up, retrospectively. Stable warfarin doses and INR per stable warfarin dose were compared according to age, gender, comorbidity, and concurrent medication. The stable warfarin dose was defined as the maintenance dose of warfarin of the measured patient whose INR was within the target INR range more than 3 times consecutively. Results: The differences of stable warfarin doses in patients with ($3.22{\pm}1.21$ mg/day) and without ($3.58{\pm}1.14$ mg/day) diuretics were marginally significant (P=0.069). On the other hand, stable warfarin doses were $2.97{\pm}1.10$ mg/day in patients with thiazide (n=36) and $3.58{\pm}1.14$ mg/day in patients without diuretics (n=82), which was statistically significant (p=0.009). INR values per stable warfarin dose in patients with diuretics and thiazide were $0.84{\pm}0.31$ and $0.90{\pm}0.34$, respectively, which were statistically different from those without diuretics ($0.72{\pm}0.21$, P=0.010 and P=0.006, respectively). Age, gender, and concurrent use of thiazide diuretics were found to have significant influence on the warfarin response from multivariate analysis. Conclusion: Our study showed that the concurrent use of thiazide diuretics could increase the response of warfarin in patient with atrial fibrillation. Therefore, clinicians should be aware that warfarin dose needs to be adjusted when it is used with thiazide diuretics concomitantly.

Granulocytic Sarcoma : 방사선 치료 성적 (Granulocytic Sarcoma: Results of Radiotherapy)

  • 송미희;정은지;성진실;서창옥
    • Radiation Oncology Journal
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    • 제10권2호
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    • pp.261-266
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    • 1992
  • 1987년 3월부터 1992년 3월까지 연세의료원 암쎈터 치료방사선과에서 방사선치료를 받은 Granulocytic sarcoma 환자를 대상으로 이들의 치료성적과 방사선 선량반응 관계를 알아보기 위해 후향성 분석을 하였다. 14예의 Granulocytic sarcoma 병변이 9예의 환자에서 발생하였고 급성, 만성 골수구성 백혈병 또는 무백헐병 상태 등과 같은 다양한 임상적 시기에 발생하였다. 병소부위는 내림 순으로 골, 임파절, 연부 조직과 피부이었다. 모든 14예의 병변은 외부 방사선(Co-60 또는 전자선)으로 치료 받았고 대다수의 병변이 2000 cGy 이상의 전 방사선 선량으로 국소 방사선 치료를 받았다. 연령 분포와 발생한 임상시기는 치료에 대한 반응과 관련이 없는 것으로 나타났다. 골에서 발생한 임상시기는 치료에 대한 반응과 관련이 없는 것으로 나타났다. 골에서 발생한 병변은 다른 부위에서 발생한 병변에 비해 치료에 대한 반응이 더 좋은 것 같았다. 2000 cGy이상의 방사선 선량을 받은 병변은 $100\%$ (l1/11)의 월등한 국소 제어율을 보였지만 2000 cGy이하의 방사선 선량을 받은 병변은 $33\%$ (1/3)의 감소된 국소 제어율을 보였다. 결론적으로 국소 방사선 치료는 Granulocytic sarcoma의 완화 또는 완치 목적의 치료에 있어 효과적이면 이때 2000 cGy이상의 방사선 선량이 필요한 것으로 생각된다.

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p53 Nuclear Accumulation as a Possible Biomarker for Biological Radio-dosimetry in Oral Mucosal Epithelial Cells

  • Kim, Youn-Young;Kim, Jong-il;Kim, Jin;Yook, Jong-In;Kim, The-Hwan;Son, Young-Sook
    • BMB Reports
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    • 제34권2호
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    • pp.123-129
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    • 2001
  • Cellular response to ionizing radiation is affected by cell types, radiation doses, and post-irradiation time. Based on the trypan blue dye exclusion assay in normal oral mucosal cells (OM cells), a 48 h post-irradiation was sufffcient and an adequate time point for the evaluation of radiation sensitivity Its $LD_{50}$ was approximately 1.83 Gy To investigate possible biomarkers useful for the biological radiodosimetry of normal epithelial cells (p53, c-fos, cyclin D1, cdc-2, pRb) EGF receptor phosphorylation and Erk activation were evaluated at different radiation doses and different post-irradiation times. From 0.5 Gy, p53 was accumulated in the nucleus of basal cells of the OM raft culture at 4 h post-irradiation and sustained up to 24 h post-irradiation, which suggests that radiation-induced apoptosis or damage repair was not yet completed. The number of p53 positive cells and biosynthesis of p53 were correlated with radiation doses. Both cyclin D1 and c-fos were only transiently induced within 1 h post-irradiation. Cyclin D1 was induced at all radiation doses. However, cfos induction was highest at 0.1 Gy, approximately 7.3 fold more induction than the control, whose induction was reduced in a reverse correlation with radiation dose. The phosphorylation pattern of cdc-2 and pRb were unaffected by radiation. In contrast to A431 tails overexpressing the EGF receptor approximately 8.5 fold higher than normal epithelial, the OM cells reduced the basal level of the EGF receptor phosphorylation in a radiation dose dependent fashion. In conclusion, among radiation-induced biomolecules, the p53 nuclear accumulation may be considered for the future development of a useful marker far biological radiodosimetry in normal epithelial tissue since it was sustained for a longer period and showed a dose response relationship. Specific c-fos induction at a low dose may also be an important finding in this study It needs to be studied further for the elucidation of its possible connection with the low dose radio-adaptive response.

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