• Title/Summary/Keyword: Dose response relationship

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Preparation of Polyphosphazene Diagnostic Membranes for Blood Glucose Measurements (혈당측정을 위한 폴리포스파젠 진단막의 제조)

  • Kwon, Suk-Ky
    • Membrane Journal
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    • v.21 no.4
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    • pp.329-335
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    • 2011
  • A new type of diagnostic membranes based on methoxyethoxy and trifluoroethoxy co-substituted polyphosphazene has been prepared to measure blood glucose level of diabetics. Final absorbances at 680 nm through activated polyphosphazene membranes were measured at various concentration of glucose in plasma or blood. The end-point results of varing absorbance values as time (K/S) was found to have a linear relationship toward the blood glucose concentration. The effects of substitution rates with hydrophilic groups and hydrophobic groups on the measurements of glucose concentration were studied. Dose-response slope (DRS) values between glucose concentration and K/S values increased as the hydrophilic substitution rates increased. However, in more than 30% of the substitution rates, it was difficult to measure exact concentration level of glucose because DRS increased rapidly.

Effect of Arsenic on Heat Shock Protein and Vascular Contractility of Rat Aorta (횐쥐 대동맥의 수축반응과 열충격단백질에 대한 비소의 영향)

  • 박태규;권윤정;김중영
    • Journal of Environmental Science International
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    • v.12 no.6
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    • pp.651-657
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    • 2003
  • In order to examine if arsenic, one of environmental stresses, contributes to hypertension as one of cardiovas cular pathological factors, this study was perfarmed in vivo and in vitro, using intacted or pithed rats and aorta ring preparation, respectively. And also the relationship between expression of heat shock protein (HSP) 90 and vasoactives-induced contractile response was elucidated. To measure blood pressure, the carotid arterial pressure was recorded on physiograph(Grass Co. 79E) connected to strain gauge. On the other hand, contractile response of vascular ring preparation isolated from rat was determined in organ bath and was recorded on physiograph connected to isometric transducer. And HSP was detacted by Western blotting whole cell Iysis. Preganglionic nerve stimulation was increased by 26.0% in arterial pressure of rat treated with arsenic. Vascular contractile response was monitored and HSP were measured by Western blotting of whole Iysis prepared from samples exposed with 0, 0.5, 1, 2 and 4 mM of arsenic for 8 hours. The dose-vascular responses of potassium chloride were augmented by increasing dose of arsenic in the strips exposed to arsenic for 8 hours, and were not augmented for 1, 3, 5 hours. And the response of relaxation of rat aorta induced by histamine was not influenced by arsenic stress. The increase of HSP 90 expression in rat aorta was pronounced at 8 hours after 4 mM of arsenic treatment, but HSP 60 expression was not. Arsenic stress not only increased the expression of HSP 90 in the rat aorta, but also augmented contractions to potassium chloride. These results indicated that arsenic stress was sufficient to induce heat shock protein 90, resulting in increased vascular contractility in rat aorta.

Radiation Effect on Airway Obstruction from Lung Cancer (폐암으로 유발된 무기폐에 대한 방사선 치료의 효과)

  • Shin, Sei-One;Kim, Sung-Kyu;Kim, Myung-Se
    • Journal of Yeungnam Medical Science
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    • v.6 no.2
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    • pp.121-125
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    • 1989
  • Total 21 patients with airway obstruction from lung cancer treated with radiotherapy at Department of Therapeuctic Radiology, Yeungnam University College of Medicine, between April 1986 and December 1988 are retrospectively analysed by means of roentgenologic findings. Obtained results are as follows. 1. 15 out of 21 patients(71%) showed complete or partial response. 2. Patients with small cell lung cancer showed 100% response in spite of low dose(30GY/10 fractions). 3. Patients with non-small cell lung cancer treated with 50GY or over showed better response than below 45GY or below. 4. There is no relationship between the response and site of airway obstruction. These data suggested that high dose irradiation is more effective in the management of airway obstruction from lung cancer and meticulous radiotherapy planning with appropriate protection of normal lung and critical organs should be investigated in order to maximize radiation effect and minimize side effect, complication or sequelae.

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A study on renal function indices in lead exposed male workers (연폭로 남자 근로자들의 신기능 지표에 관한 연구)

  • Lee, Sung-Soo;HwangBo, Young;Ahn, Kyu-Dong;Lee, Byung-Kook;Kim, Joung-Soon
    • Journal of Preventive Medicine and Public Health
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    • v.28 no.2 s.50
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    • pp.421-432
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    • 1995
  • The influence of lead exposure on renal function was studied. Eighty nine lead exposed workers who worked in 2 storage battery factories, and seventy one control workers were chosen for this study. Blood lead(PbB) and zinc protoporphyrin in whole blood(ZPP) were selected as indicators of lead exposure. As indicators of renal function, urinary N-acetyl-$\beta$-D-glucosaminidase(NAG), blood urea nitrogen(BUN), serum creatinine(S-Cr), total protein in urine(U-TP),and serum uric acid(S-Ua) were selected. The results obtained were as follows: 1. While the mean values of lead exposure indicators of lead workers were significantly different from non-exposed ones, the mean values of NAG, U-TP, BUN and S-Cr of renal function indicators of exposed were also significantly different from non-exposed but their mean values were all within normal limits. 2. BUN, logarithmic U-TP, logarithmic NAG and S-Cr showed statistically significant correlation with PbB. 3. The proportion of workers whose values of renal function indicators were over the normal limits(NAG7.5 U/g Cr ; U-TP10.9 mg/dl ; BUN20 mg/dl ; S-Crl.2 mg/dl ; S-Ua7.0 mg/dl) by the level of lead absorption in terms of PbB and ZPP were calculated. The proportion of workers with over the normal limits of U-TP among total workers showed the dose-response relationship. When age is adjusted, U-TP showed significantly strong dose-response relationship with the level of PbB and ZPP.

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

  • Lee, In-Sup;Zo, Young-Gun
    • Korean Journal of Microbiology
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    • v.49 no.4
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    • pp.360-368
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    • 2013
  • Recently interactive water fountains are gaining popularity in making public facilities in South Korea. The total number of interactive fountains is rapidly growing at the rate of >50% annually. In this study, we performed quantitative microbial risk assessment to estimate infection risks in children by Legionella spp. while playing in interactive fountains. The exposure dose for a given concentration of Legionella in water was calculated using water-aerosol partition rate of Legionella, exposure duration, inhalation rate, and deposit rate of aerosols in the lungs following inhalation. The dose was converted to infection risk by using the dose-response function developed for L. pneumophila. High weight and/or old children, i.e., 12-year children, running around in fountains were the highest risk group by showing >0.05 infection probability for fountain waters containing ${\geq}10^4$ CFU/L Legionella. The result supported the current guideline by Korea Centers for Disease Control and Prevention, which permits use of water with < $10^3$ CFU/L Legionella cells for all purposes. However, the results still warrant further evaluation of the guideline to accommodate risks for children because the dose-response relationship in the model was developed for healthy adults. Further risk assessment studies need to be conducted by employing dose-response model for children who generally carries weaker immune system than adults.

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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    • v.34 no.2
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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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Four-week Oral Toxicity Study of DA-9601, an Antiulcer Agent of Artemisia spp. Extract, in Rats (애엽추출물 항궤양제 DA-9601의 랫드에 대한 4주 경구 반복투여 독성연구)

  • 김옥진;강경구;김동환;백남기;안병옥;김원배;양중익
    • Biomolecules & Therapeutics
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    • v.4 no.4
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    • pp.354-363
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    • 1996
  • This study was conducted to investigate the repeated dose toxicity of DA-9601, an antiulcer agent of Artemisia app. extract, in rats. DA-9601 was administered orally once a day for 4 weeks to 10 males and 10 females per group at doses of 0(vehicle control), 125, 500 or 2000 mg/kg/day. Throughout the study, no treatment-related deaths and clinical signs were observed. In female rats receiving 125 mg/kg of DA-9601, water consumption increased slightly on day 4, 11 and 25. Hematological examination showed a decrease of MCV and an increase of PLT in male rats at the doses of 500 and 2000 mg/kg groups. Blood biochemistry revealed slight decreases of cholesterol, BUN and Na in male rats and decreases of total bilirubin and creatinine and slight increases of globulin and Cl in female rats. The organ weights at the end of 4 weeks showed slight changes in some organs of treated groups. But, all these changes were not considered to be of toxicological importance, because they did not show dose-response relationship and relevance to gross and microscopic findings. Histopathologically, abnormal treatment-related changes were not observed in any organ and target organs were not detected. On the basis of these results, the NOAEL(no-observed-adverse-effect level) of DA-9601 was estimated to be more than 2000 mg/kg/day under the conditions tested.

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CELL-MEDIATED IMMUNE PROCESSES AND CONTROL OF CANCER

  • Lee, Kwon-Soon;Chung, Hyeng-Hwan
    • Proceedings of the KOSOMBE Conference
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    • v.1991 no.05
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    • pp.82-85
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    • 1991
  • Cell kinetics and the chemical mass action principle formulate the basis of immune system dynamics which may be synthesized mathematically as cascades of bilinear systems which are connected by nonlinear nondynamical terms. In this manner, a model for cell-mediated immune response (CMI) to tumor antigens and debris is developed. We also consider parametric control variables relevant to the latest experimental data, i.e., sigmoidal dose-response relationship and Michaelis-Menten dynamics. The preliminary results show that the parametric control variable is important in the destruction of tumors. As well as that, the exacerbation theory is a good method for tumor treatment. Finally, tumor control as an application of immunotherapy is analyzed from the basis established above.

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Serum IgE Immune Response on the Exposure of Korean Ginseng

  • 이종화;박경미;박화진
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.315-315
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    • 1994
  • Recently, it was reported that Pfaffia paniculata, known as Brazil ginseng, caused occupational asthma. To assess a potential relationship between Korean ginseng and allergic reactions, total IgE in serum, allergologic parameter, was investigated. Serum total IgE were measured in 8 takers of ginseng for more than 5 yr, 4 subjects of weak constitution, 10 workers participated in the washing of fresh ginseng in factory and 7 control subjects, Blood samples were taken before and after the scheduled exposure to Korean ginseng, sera were kept frozen until assay. Total IgE levels after the scheduled exposure to Korean ginseng were not significantly different in each group and total IgE levels were not significantly different in the control subjects compared with those of other groups at the start of experiment and at the end of experiment. These results suggest that the exposure to Korean ginseng dose not affect significantly the IgE immune response in volunteers. No changes of levels of IgE on the exposure of Korean ginseng may represent additional evidence of the lack of antigenic potential of Korean ginseng.

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Serum IgE Immune Response After the Exposure to Korean Ginseng (고려인삼이 혈청 면역글로부린 E 면역반응에 미치는 영향)

  • Lee, Jong-Wha;Park, Kyeong-Mee;Park, Ki-Hyun
    • Journal of Ginseng Research
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    • v.18 no.2
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    • pp.113-117
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    • 1994
  • To assess a polential relationship of Korean ginseng to allergic reactions, the effect of Korean ginseng on the total IgE in serum as an allergologic parameter was investigated in humans. Serum total IgE levels were measured in 8 subjects who have been taking ginseng for more than 5 years, 4 subjects of weak constitution, 10 newly hired workers in the ginseng processing industry and 7 normal subjects unexposed to Korean ginseng as control group. Blood samples were taken before and after the exposure to Korean ginseng. Total IgE levels after the exposure to Korean ginseng were not significantly different from those before the exposure within each group. And also, the IgE levels of control subjects were not significantly different compared with those of other groups. These results suggest that the exposure to Korean ginseng dose not affect significantly the IgE immune response of the subjects.

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