• Title/Summary/Keyword: Dose-response Function

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Effects of chloramphenicol on chemiluminescence response of leukocytes isolated from olive flounder, Paralichthys olivaceus (양식산 넙치, Paralichthys olivaceus 식세포의 식작용 활성에 미치는 chloramphenicol의 영향)

  • Seo, Jeong-Su;Jeong, So-Jeong;Lee, Sang-Hwan;Kim, Na-Yeong;Eom, Hye-Gyeong;Heo, Min-Do;Jeong, Hyeon-Do;Jeong, Jun-Gi
    • Journal of fish pathology
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    • v.17 no.3
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    • pp.217-222
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    • 2004
  • This study was performed to investigate the immunological side effects of chloramphenicol (CAP) on olive flounder, Paralichthys olivaceus. To investigate immunological effects on olive flounder, we determined the changes of chemiluminescence (CL) response of flounder kidney-derived leucocyte after the treatment of CAP in vivo and in vitro. The CL activity was significantly decreased in a dose-dependent manner during the treatment of CAP in vitro. Similarly, a dose-dependent reduction of CL response, although not significant, were observed during the treatment of CAP in vivo. The results suggest that CAP reduced the function of flounder phagocytosis in vivo and in vitro, indicating the immunosuppressive ability of CAP.

Basic Dose Response of Fluorescent Screen-based Portal Imaging Device (섬광판을 사용하는 조사문영상기구의 기본적인 선량반응성)

  • Yeo, In-Hwan J.;Yohannes, Yonas;Zhu,Yunping
    • Radiation Oncology Journal
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    • v.17 no.3
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    • pp.249-255
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    • 1999
  • Purpose : The purpose of this study is to investigate fundamental aspects of the dose response of fluorescent screen-based electronic portal imaging devices (EPIDS). Materials and Methods : We acquired scanned signal across portal planes as we varied the radiation that entered the EPID by changing the thickness and anatomy of the phantom as well as the air gap between the phantom and the EPID. In addition, we simulated the relative contribution of the scintillation light signal in the EPID system. Results : We have shown that the dose profile across portal planes is a function of the air gap and phantom thickness. We have also found that depending on the density change within the phantom geometry, errors associated with dose response based on the EPID scan can be as high as $7\%$. We also found that scintillation light scattering within the EPID system is an important source of error. Conclusion : This study revealed and demonstrated fundamental characteristics of dose response of EPID, as relative to that of ion chambers. This study showed that EPID based on fluorescent screen cannot be an accurate dosimetry system.

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Radiation Therapy for Bone Metastases from Hepatocellular Carcinoma: Effect of Radiation Dose Escalation (간세포암에 의한 뼈전이의 방사선치료: 고선량 방사선치료의 효과)

  • Kim, Tae-Gyu;Park, Hee-Chul;Lim, Do-Hoon;Kim, Cheol-Jin;Lee, Hye-Bin;Kwak, Keum-Yeon;Choi, Moon-Seok;Lee, Joon-Hyoek;Koh, Kwang-Cheol;Paik, Seung-Woon;Yoo, Byung-Chul
    • Radiation Oncology Journal
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    • v.29 no.2
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    • pp.63-70
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    • 2011
  • Purpose: To evaluate the extent of pain response and objective response to palliative radiotherapy (RT) for bone metastases from hepatocellular carcinoma according to RT dose. Materials and Methods: From January 2007 to June 2010, palliative RT was conducted for 103 patients (223 sites) with bone metastases from hepatocellular carcinoma. Treatment sites were divided into the high RT dose and low RT dose groups by biologically effective dose (BED) of 39 $Gy_{10}$. Pain responses were evaluated using the numeric rating scale. Pain scores before and after RT were compared and categorized into 'Decreased', 'No change' and 'Increased'. Radiological objective responses were categorized into complete response, partial response, stable disease and progression using modified RECIST (Response Evaluation Criteria In Solid Tumors) criteria; the factors predicting patients' survival were analyzed. Results: The median follow-up period was 6 months (range, 0 to 46 months), and the radiologic responses existed in 67 RT sites (66.3%) and 44 sites (89.8%) in the high and low RT dose group, respectively. A dose-response relationship was found in relation to RT dose (p=0.02). Pain responses were 75% and 65% in the high and low RT dose groups, respectively. However, no statistical difference in pain response was found between the two groups (p=0.24). There were no differences in the toxicity profiles between the high and low RT dose groups. Median survival from the time of bone metastases diagnosis was 11 months (range, 0 to 46 months). The Child-Pugh classification at the time of palliative RT was the only significant predictive factor for patient survival after RT. Median survival time was 14 months under Child-Pugh A and 2 months under Child-Pugh B and C. Conclusion: The rate of radiologic objective response was higher in the high RT dose group. Palliative AT with a high dose would provide an improvement in patient quality of life through enhanced tumor response, especially in patients with proper liver function.

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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Risk Assessment for Toluene Diisocyanate and Respiratory Disease Human Studies

  • PARK, Robert M.
    • Safety and Health at Work
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    • v.12 no.2
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    • pp.174-183
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    • 2021
  • Background: Toluene diisocyanate (TDI) is a highly reactive chemical that causes sensitization and has also been associated with increased lung cancer. A risk assessment was conducted based on occupational epidemiologic estimates for several health outcomes. Methods: Exposure and outcome details were extracted from published studies and a NIOSH Health Hazard Evaluation for new onset asthma, pulmonary function measurements, symptom prevalence, and mortality from lung cancer and respiratory disease. Summary exposure-response estimates were calculated taking into account relative precision and possible survivor selection effects. Attributable incidence of sensitization was estimated as were annual proportional losses of pulmonary function. Excess lifetime risks and benchmark doses were calculated. Results: Respiratory outcomes exhibited strong survivor bias. Asthma/sensitization exposure response decreased with increasing facility-average TDI air concentration as did TDI-associated pulmonary impairment. In a mortality cohort where mean employment duration was less than 1 year, survivor bias pre-empted estimation of lung cancer and respiratory disease exposure response. Conclusion: Controlling for survivor bias and assuming a linear dose-response with facility-average TDI concentrations, excess lifetime risks exceeding one per thousand occurred at about 2 ppt TDI for sensitization and respiratory impairment. Under alternate assumptions regarding stationary and cumulative effects, one per thousand excess risks were estimated at TDI concentrations of 10 - 30 ppt. The unexplained reported excess mortality from lung cancer and other lung diseases, if attributable to TDI or associated emissions, could represent a lifetime risk comparable to that of sensitization.

Immunotoxicity of Organophosphorous Pesticides, Pirimiphos-methyl and Methidathion in Balb/c Mice (Balb/c 마우스에서 유기인계 농약인 Pirimiphos-methyl 및 Methidathion의 면역독성)

  • Eam Juno H.;Chung Seung-Tae;Park Jae Hyun;Kil Jung Hyun;Lee Jong Kwon;Oh Hye Young;Kim Hyung Soo
    • Toxicological Research
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    • v.20 no.4
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    • pp.329-337
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    • 2004
  • Primiphos-methyl and methidathion as organophosphorus (OP) pesticides were tested for their immunotoxic effects on Balb/c mice. Three dose levels of primiphos-methyl (10, 60, or 120 mg/kg/day) and methidathion (0.5, 2.5 or 5.0 mg/kg/day) were administered orally in the mice for 4 weeks. After, changes in body weight gain, relative weight of spleen and thymus, viable splenic cell numbers, surface marker on immune cell, and proliferation activity were investigated. Results showed that neither Pirimiphos-methyl nor methidathion dosages changed significantly body weight, relative thymus and spleen weight, and thymus and spleen cellularities of the mice, but high dose treatment (120 mg/kg) of pirimiphos-methyl significantly decreased relative spleen weight and spleen cellularity of the mice. No alterations were observed in changes of LPS-proliferation response of splenocytes by exposure to any dose of pirimiphos-methyl and methidathion. However, pirimiphos-methyl dosages reduced ConA-proliferation response of splenocytes and both methidathion and pirimiphos-methyl decreased the ability of antibody production to SRBC. The results indicate that 28 days exposure to the high dose of pirimiphos-methyl suppress the function of splenic T and B cell function, and methidathion reduce the immune responsibility of B cell in mice without the changes in lymphoid organ weight or viability of splenocytes. Pirimiphos-methyl is more immunotoxic than methidathion although this has higher general toxicity than that.

The Effects of High-dose Vitamin C Administration on the Cell-mediated Immune Response in Mice (다용량 비타민 C 투여가 생쥐 세포매개면역반응에 미치는 영향)

  • Noh, Kahwa;Kim, Heun-gon;Shin, Young-ah;Lim, Hyunja;Mun, Sung-kyu;Lee, Yongtaek;Lee, Wang Jae;Lee, Dongsup;Hwang, Young-il
    • IMMUNE NETWORK
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    • v.3 no.3
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    • pp.211-218
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    • 2003
  • Background: Vitamin C is an essential nutrient, taken as a daily supplement by many people. Recently, high-dose vitamin C is considered as a therapeutic regimen in some clinical situations. Until now, few studies have been done with the effects of high-dose vitamin C on the immune response. Methods: In this experiment, the effects of high-dose vitamin C on cell-mediated immune response in immunologically competent mice were evaluated. After intraperitoneal injection of 2.5, 5, or 10 mg/day of vitamin C for 10 days, delayed type hypersensitivity (DTH) was provoked against DNFB in the pinnae as a model for cell-mediated immune response. Severity of DTH reaction was evaluated as the thickness of pinnae, and the vitamin C levels were measured in the serum, liver, kidney, lung, pinnae, and splenocytes. Results: After challenge, the thickness increased at its peak on the $2^{nd}$ day in all groups. On the first day, the pinnae were thicker in the injected groups than in the control. On the contrary, the increment of the pinnae thickness was attenuated and the number of cells infiltrated in the site of DTH decreased proportionately to the amount of vitamin C administered from the second day on. With vitamin C exogenously given, the serum level peaked at 30 min after injection, and returned abruptly to its basal level without accumulation. However, it accumulated in the liver, kidney, and especially in the pinnae inflamed and splenopcytes, proportionately to the amount administered. Conclusion: Based on these results, it is suggested that, in one hand, exogenously administered high-dose vitamin C accumulated in the splenocytes and presumably changed the function of them resulting in the augmented cell-mediated immune response, as was revealed in the first day of DTH reaction. On the other hand, it seems likely that the vitamin C also showed anti-inflammatory effects.

Receptor Specificity of Adenosine Analogs in Terms of Renal Function and Renin Release (Adenosine 유사체의 신장효과에 미치는 Adenosine 차단제의 영향)

  • Yun, Young-Yi;Koh, Gou-Young;Kim, Suhn-Hee;Cho, Kyung-Woo
    • The Korean Journal of Physiology
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    • v.24 no.2
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    • pp.269-280
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    • 1990
  • The purpose of the present experiment was to determine the functional subclassification of renal adenosine receptor fer the hemdynamic, excretory and secretory functions in unanesthetized rabbits. Adenosine antagonist, 8-phenyltheophylline (8-PT) or theophylline, was infused into the left renal artery followed by an infusion of adenosine agonist, cyclohexyladenosine (CHA) or 5'-N-ethylcarboxamidoadenosine (NECA). Intrarenal arterial infusion of CHA or NECA caused decreases in urine volume, glomerular filtration rate, renal plasma flow and excreted amount of electrolytes and renin release in a dose-dependent manner. Dose-response curves in renal function by CHA or NECA was similar and shifted to the right with pretreatment of 8-PT or theophylline. No significant differences in renal response to CHA and NECA in antagonist-treated rabbits were observed. However, the decrease in renin secretion rate was not affected by the adminstration of adenosine antagonists. These results suggest that the renal effect of adenosine receptor agonists appears by way of specific adenosine receptor, but which is not functionally subclassified in the rabbit.

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Influence of Juncus decipiens $N_{AKAI}$ on the Renal Function of Dogs (등심초(燈心草)의 개 신장(腎臟) 기능(機能)에 미치는 영향(影響))

  • Moon, Yung-Hee
    • Korean Journal of Pharmacognosy
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    • v.6 no.2
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    • pp.101-110
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    • 1975
  • In this study attempts were made to explore effects of the water and alcohol extracts of Junci Herba on the renal function of dogs. The water extract (in a dose 15 mg/kg, i.v.) and alcohol extract (in a dose 1.5 mg/kg, i.v.) elicited a diuretic response and produced a marked diuresis during bicarbonate infusion whereas no diuresis ensues during infusion of hydrochloric acid. The ratios of potassium and sodium excreted in urine $(K^+/Na^+)$, pH of urine, Cosm (osmolar clearance) and $C_{H_2O}$ (free water clearance) increased but hemodynamic states changed little with both extracts. All the observed facts can be best explained on the assumption that Junci Herba inhibits the carbonic anhydrase in the tubule. Thus it produces the effect by increasing urinary potassium and sodium.

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Influence of Intraventricular Ouabain on the Renal Function of the Rabbit (가토(家兎) 신장기능(腎臟機能)에 미치는 측뇌실내(側腦室內) Ouabain의 영향(影響))

  • Lee, Shin-Woong
    • The Korean Journal of Pharmacology
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    • v.12 no.1
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    • pp.31-44
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    • 1976
  • It has been reported that many of the effects of digitalis glycosides could be mediated partly through the central nervous system. In this study the effects of ouabain given directly into the lateral ventricle of the brain on the renal function of the rabbit were investigated. Intraventricular ouabain elicited antidiuresis in doses ranging from 0.1 to $3\;{\mu}g$, exhibiting a rough dose-response relationship, and decreased the renal plasma flow, glomerular filtration rate and urinary excretion of sodium and potassium, concomitant with the decrease of urine flow. These decreases in urine flow, excretory rate of electrolytes significantly correlated with the decrease in renal plasma flow or glomerular filtration rate, suggesting that the antidiuresis might have been induced by the hemodynamic changes. Intravenous ouabain in a dose of $1\;{\mu}g$ did not affect the renal function. Systemic blood pressure as well as cardiac activity was not affected by the intraventricular ouabain. Effects of the intraventricular ouabain on renal function were abolished by the intravenous phentolamine-pretreatment but not affected by intraventricular phentolamine-pretreatment. Neither vasopressin infusion nor hydration did affect the renal effects of intraventricular ouabain. From these observations, it is suggested that the antidiuresis of intraventricular ouabain is induced by the increased sympathetic influence to the kidney.

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