• Polymer(Korea)
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• v.27 no.3
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• pp.255-264
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• 2003

Various chain sizes 3-arm star polystyrenes (PS, $M_{w}$=2.80$\times$10$^{5}$ , 2.49$\times$10$^{6}$ g/mol) in t-decalin solution were measured at the temperature range of 20~7$0^{\circ}C$ by means of viscometry and laser light scattering. In order to show universality in the expansion factor of 3-arm star polymer, it was expected that (N/ $R_{G,Br,o}$$^{2}$)$^{3}$2/$\tau$/$\tau$$_{C}$ would be used as an universal parameter, where $R_{G,Br,o}$ was the unperturbed radius of gyration of star PS. However, much better universality had been observed when (N/ $R_{G,Br,o}$$^{2}$)$^{3}$2/$\tau$/$\tau$$_{C}$ parameter of the linear PS was used even for the 3-arm star PS. It could be explained if branching effect had been already taken into account in the part of $\tau$/$\tau$$_{C}$(=[(Τ-Θ$_{Tc}$ )/Θ$_{Tc}$ ]/[(Θ$_{Tc}$ -Τ$_{c}$)/ $T_{c}$]). Here N and Θ$_{Tc}$ stand for the number of monomer unit in a single polymer chain and a kind of theta temperature as the critical solution temperature $T_{c}$ of the infinite molecular weight, respectively.ely.y.ely.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.98-104
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• 1995

Recently murine monoclonal antibodies have been studied actively for radioimmuno-scintigraphy and radioimmunotherapy, especially on patients with leukemia and lymphoma. In this research, we studied radiolabeling and immunologic characteristics of two in-house anti-leukemic monoclonal antibodies(anti-CALLA & anti-JL-1 antibodies) to make the basis for their clinical application. Each antibody was radiolabeled successfully with $^{99m}Tc$ by pretargeting transchelation method and with $^{125}I$ by lodogen method. We also studied cell binding assay, Scatchard analysis and modulation phenomenon. $^{125}I$ showed 90% labeling efficiency for each anti-body which was satisfactory, but $^{99m}Tc$ showed labeling efficiency below 70%, for which we need better labeling method. In cell binding assay, the immunoreactivity(IR) was low for $^{99m}Tc$-labeled antibodies. Scatchard analysis showed satisfactory data for both binding affinity. The affinity constant and antibody binding sites per cell are around $10^9M^{-1}$ and $10^4$, respectively. There was no modulation phenomenon in cases of $^{125}I$ or $^{99m}Tc$ labeled antibodies. We expect that two anti-leukemic monoclonal antibodies may be useful in diagnosis and therapy for leukemia and lymphoma patients.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.1006-1015
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• 2005

We investigated the effect of hydroxyl radicals on the photolysis of triclosan (TCS), which is a potent broad-spectrum antimicrobial agent. TCS degradation during the initial reaction time of 5 min followed a pseudo-first order kinetic model ai all light intensities at a wavelength of 365 nm and at the low light intensities at a wavelength of 254 nm. The photodegradation rate significantly increased with decreasing wavelength and increasing the UV intensities. The activity of hydroxyl radicals was suppressed when methanol was used as the solvent instead of water. An increase in the photon effect was observed when the UV intensity was higher than $5.77{\times}10^{-5}$ einstein $L^{-1}min^{-1}$ at 254 nm, and lower than $1.56{\times}10^{-4}$ einstein $L^{-1}min^{-1}$ at 365 nm. The quantum yield efficiency for the photolysis of TCS was higher at 365 nm than at 254 nm among the above mentioned UV intensities. Dibenzodichloro-p-dioxin (DCDD) and dibenzo-p-dioxin were detected as intermediates at both UV intensities of $1.37{\times}10^{-4}$ and $1.56{\times}10^{-4}$ einstein $L^{-1}min^{-1}$ at 365 nm. Dichlorophenol and phenol were also detected in all cases. Based on our findings, we presented a possible mechanism of TCS photolysis.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.943-948
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• 2021

The purpose of this study was to investigate changes in surface dose due to increased scattering of gamma rays from patients injected with ^99mTc and ¹⁸F, which are radioactive isotopes, in close contact with materials with high atomic number such as the walls of the stable room. Prepare ^99mTc and ¹⁸F by injecting 20 and 10 mCi respectively into the NEMA phantom, and then measuring the surface dose for 60 minutes by positioning the phantom at a height of 1 m above the surface, at a distance of 0, 5 and 10 cm from the wall, and at the same location as the phantom facing the wall. Each experiment was repeated five times for reproducibility of the experiment and one way analysis of variability (ANOVA) was performed for significance testing and Tukey was used as a post-test. The study found that surface doses of 220.268, 287.121, 243.957, and 226.272 mGy were measured at ^99mTc, respectively, in the case of empty space and in the case of 0, 5 and 10 cm, while those of ¹⁸F were measured at 637.111, 724.469, 657.107, and 640.365 mGy, respectively. In order to reduce changes in surface dose depending on the patient's location while waiting, it is necessary to keep the distance from the ground or the wall where the patient is closely adhered to, or install an air mattress, etc., to prevent the scattered lines as much as possible, considering the scattered lines due to the wall etc. in future setup of the patient waiting room and safety room, and in addition to the examination, the external skin width may be reduced.

• Journal of Life Science
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• v.16 no.6
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• pp.1060-1065
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• 2006

Non-invasive evaluation of liver function in animal models remains a challenge. Hepatoscintigraphy provides information about changes in liver size and shape, and enables to understand general liver function. Futhermore it is readily used to diagnosis complications of liver transplantation like hepatitis, rejections and biliary complications. In this study, we investigated the usefulness of evaluating the liver function in miniature pigs with $^{99m}Tc-Tin$ colloid and $^{99m}Tc-DISIDA$ which are the most commonly used radiopharmaceuticals in human medicine. In result, $^{99m}Tc-Tin$ colloid was uptaked in lung, liver, gastric wall and kidney in miniature pigs. And $^{99m}Tc-DISIDA$ showed continuous uptake images of heart, lung, liver, gallbladder and duodenum, and it was similar to human's. Therefore we could conclude $^{99m}Tc-Tin$ colloid would not be suitable for evaluating hepatic function because of it's nonspecific affinity, however $^{99m}Tc-DISIDA$ scintigraphy would be an effective method for detecting hepatobiliary function in miniature pigs.

• Childhood Kidney Diseases
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• v.17 no.2
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• pp.57-64
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• 2013

Purpose: In children, 24-hour urine collections are unreliable for evaluating glomerular filtration rate (GFR) because of the difficulty of regulating voiding and the daily variation of urinary creatinine up to 25%. Additionally, creatinine clearance (Ccr) based on urinary creatinine is considered inaccurate. The purpose of this study was to compare estimated GFR determined using Ccr, formulas with serum cystatin C and creatinine, and $^{99m}Tc$-mercaptoacetyltriglycine (MAG3) dynamic renal scintigraphy. Methods: This retrospective study included 101 patients (age, <18 years) who visited Chung-Ang University Hospital between July 2011 and August 2012. GFR was estimated using 24-hour urinary creatinine, five formulas with serum creatinine and cystatin C, and $^{99m}Tc$-MAG3 renal scan. Results: Of the 101 patients, glomerular renal diseases were present in 60 patients (59.4%) and non-glomerular diseases were present in 41 patients (40.6%). There was a significant correlation between estimated GFR determined using $^{99m}Tc$-MAG3 renal scan and Ccr (r=0.389, P <0.001). The correlation values between estimated GFR determined using $^{99m}Tc$-MAG3 renal scan and each formula of Schwartz, Counahan-Barratt, Cockcroft-Gault, Filler and Lepage, and Bokencamp were 0.265 (P=0.007), 0.128 (P=0.044), 0.230 (P=0.021), 0.356 (P<0.001), and 0.355 (P <0.001), respectively. $^{99m}Tc$-MAG3 renal scan was correlated with estimated-GFR by all formulas in decreased renal function. Conclusion: Estimated GFRs determined using serum creatinine and cystatin C, and $^{99m}Tc$-MAG3 renal scan correlated well with estimated GFR determined using Ccr. $^{99m}Tc$-MAG3 renal scan may be replaced for evaluation of renal function with convenience in patients with renal disease and decreased renal function in childhood.

• The Korea Journal of Herbology
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• v.29 no.6
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• pp.21-26
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• 2014

Objectives : Taraxacum coreanum (TC) have been used as a traditional medicine to treat inflammatory diseases and anti-oxidant effect in Korea. However, the anti-inflammatory effect of TC water extract on lipopolysaccharide (LPS)-induced inflammation is not well-known. Therefore, this study was performed to identify the anti-inflammatory effect of TC on LPS induced inflammatory. Methods : RAW 264.7 cells were treated with 500 ng/mL of LPS. Water extracts of TC (0.1, 0.25, 0.5 mg/ml) was treated 1 h prior to LPS. Cell viability was measured by MTT assay. Levels of nitric oxide (NO) were measured with Griess reagent and pro-inflammatory cytokines were measured by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (real-time PCR). We also examined molecular mechanisms such as mitogen-activated protein kinases (MAPKs) and nuclear factor-B ($NF-{\kappa}B$) activation by western blot. Results : Water Extract from TC itself did not have any cytotoxic effect in RAW 264.7 cells. TC treatment inhibited the production of NO production, and pro-inflamamtory cytokines such as interleukin (IL)-6 and $IL-1{\beta}$ on protein and mRNA levels. In addition, TC treatment inhibited the LPS-induced activation of MAPKs such as extracellular signal-regulated kinase1/2 (ERK1/2), p38 kinases (p38), c-Jun $NH_2$-terminal kinase (JNK) and $NF-{\kappa}B$. Conclusions : In summary, our result suggest that treatment of TC could reduce the LPS-induced inflammation. Thereby, TC could be used as a protective agent against inflammation. Also, this study could give a clinical basis that TC could be a drug or agent to prevent inflammation.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.1
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• pp.25-29
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• 2009

Purpose: Several radioactive agents were used for lymphoscintigraphy in breast cancer. But recently, due to the change of local radiopharmaceutical licensing policy and discontinuation of supplies from manufacturer, we could not use many radiocolloids such as $^{99m}Tc$-Antimony Trisulfide Colloid, $^{99m}Tc$-Tin Colloid, $^{99m}Tc$-Human Serum Albumin. So it is necessary to use the substitution radiopharmaceutical. Therefore, this study aims to evaluate the performance of substitution radiopharmaceutical ($^{99m}Tc$-Phytate) including the existing radiocolloids and to set up of the appropriate protocol in lymphoscintigraphy. Materials and Methods: For each radiocolloids ($^{99m}Tc$-Antimony Trisulfide Colloid (ASC), $^{99m}Tc$-Tin Colloid (TC), $^{99m}Tc$-Human Serum Albumin (HSA), $^{99m}Tc$-Phytate) were performed the particle size by Zeta Sizer (Nano-ZS) and we compared the radiolabeling time, procedure and acquisition time for each of the radiocolloids (total 200 patients). For the last time, we made an analysis of image for each of the radiocolloids with our previous report (SJ Jang et al, Korean Nucl Med Mol imaging Vol.41, No.6, Dec 2007). Results: The particle size of each radiocolloids showed A.S.C (50 nm), T.C (310 nm), H.S.A (10.8 nm), $^{99m}Tc$-Phytate (499 nm). The labeling and acquisition time for each of the radiocolloids showed no substantial difference. But there is difference of the labeling time for the A.S.C. because the ASC procedure need to boiling process. There were no significant differences among those radiocolloids (p>0.005) in the identification rate (IR), false negative rate (FNR), and negative predictive value (NPV). Conclusions: $^{99m}Tc$-labeled radiocolloids showed equivalent results in lymphoscintigraphy. Therefore, in this exam of each radiocolloids could be applied appropriate protocol in lymphoscintigraphy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.285-292
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• 2017

The purpose of this study was to investigate the relationship between the fasting blood sugar and serum lipid levels (TC, TG, HDL-C, LDL-C) and obesity indices (BMI, body fat rates, waist circumference, waist to hip ratio). The study sample consists of 1,473 manufacturing workers aged from 30 to 59 years, who underwent a health check-up at a university hospital during the period from Jan. to Dec. 2015. A data analysis was conducted to classify the subjects into the normal and abnormal groups according to their fasting blood sugar levels depending on the average values of the serum lipids and obesity indices. Multiple regression analyzes adjusted for sex and age were conducted for the factors affecting the fasting blood sugar level. As a result, the Serum TC, TG, LDL-C, BMI and waist circumference were found to be significantly higher in the abnormal fasting blood sugar level group than in the normal one, but the HDL-C was significantly lower in the abnormal group than in the normal one The fasting blood sugar level had a significant positive correlation with the TC, TG, LDL-C, BMI and waist circumference. The TC, TG, BMI and body fat were the significant factors affecting the fasting blood sugar. The above results suggest that the fasting blood sugar and serum lipid levels (TC, TG, HDL-C, LDL-C), obesity indices (BMI, body fat rates, waist circumference, waist to hip ratio) of manufacturing workers are significantly associated with each other.

• The Korean Journal of Nuclear Medicine
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• v.16 no.2
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• pp.71-80
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• 1982

In the present communication, the results will be reported on a clinical study of how well scintigraphic visualization of the hepatobiliary elements and several commonly used clinical liver function tests correlate each other in various diseases oft hepatobiliary system. The demonstrability of the biliary tract, gallbladder (GB) and duodenum was rather closely paralleled to serum bilirubin level and less closely to alkaline phosphatase and rather poorly to SGOT and SGPT. The biliary tree could not be visualized scintigraphically when bilirubin exceeded 10.5mg/dl. The usefulness of Tc-99m EHIDA [N-(2,6-diethylacetanilido) iminodiacetic acid, made by Amersham, England] hepatobiliary scintigraphy (Tc EHIDA HBS) in settling diagnostic controversy and ambiguity raised by oral cholecystography, intravenous cholangiography and ultrasonography in many hepatobiliary diseases is well known. The purpose of this investigation was to semiquantitatively evaluate the scintigraphic demonstrability of the hepatobiliary tract, GB and duodenum following intravenous injection of Tc-99m EHIDA in normal subjects and in patients with a disturbed liver function from various hepatobiliary diseases. The hepatobiliary scintigraphy was performed in 10 normal subjects and 39 patients with various hepatobiliary diseases (Table 1) at the Dept. of Radiology, St. Mary's Hospital Catholic Medical College, Seoul, Korea during 2 years period from September 1979. Scintigraphic examination was started at end of 3 minutes after intravenous injection of Tc-99m EHIDA in the amount of $50{\mu}Ci/kg$ and was continued until after 30 minutes at 5 minutes interval. The imaging was usually terminated when the tracer could be seen in the duodenum. Late scintigrams were obatained at 1 1/2, 3, 4 and 6 hours when reeded. Scintigrams were analyzed in terms of promptness and clarity of visualization of the biliary tree, GB and duodenum and demonstrability of these anatomical landmarks was correlated with the values of liver function tests. The demonstrability of the common hepatic duct, common bile duct, GB and duodenum was closely paralleled to the level of serum bilirubin when it is less than 10.5 mg/dl as shown in figure 1. However when the bilirubin exceeded 10.5 mg/dl the time of visualization between protracted reaching a flat curve or plateau around 10.5 mg/dl. The biliary tract could not be visualized when the bilirubin was higher than 10.5 mg/dl. The correlability between scintigraphic demonstration and serum alkaline phosphatase was less strong and between scintigraphic demonstration and SGOT and SGPT was rather poor. The present clinical study confirmed the usefulness and limitation of Tc-99m EHIDA hepatobiliary scintigraphy in visulizing and diagnosing the biliary system and duodenum when radiogrpahy and ultrasonography failed to provide useful informations. Scintigraphy was very helpful in the diagnosis of neonatal hepatitis, biliary atresia, cholecystitis and extrahepatic biliary obstruction. The hepatobiliary system and duodenum were visualized when serum bilirubin level was less than 10.5 mg/dl, SGOT 135 units, SGPT 114 units and alkaline phosphatase 52.2 KAU.