• Journal of the Korean Society of Radiology
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• v.14 no.1
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• pp.15-22
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• 2020

PET(Positron Emission Tomography) devices are used as PET/CT or PET/MRI devices fused with the devices of CT or MRI for obtaining anatomical information. Therefore, the devices are constructed in circular ring-type structure whose length of gantry(the main part of filming) becomes wider and the interior depth becomes longer in comparison to other common medical equipments. scintillator, one of the components in PET devices, is inside the gantry, and as it is consisted of crystal which is sensitive to the change of temperature and humidity, large temperature change can cause the scintillator to be damaged. Though scintillator located inside the gantry maintains temperature and humidity with a thermo-hygrostat, changes in temperature and humidity are expected due to structural reasons. The output value was measured by dividing the inside of the gantry of the PET/CT device into six zones, each of which an Adafruit BME 280 temperature and humidity sensor was placed at. A thermo-hygrostat keeps the temperature and humidity constant in the PET/CT room. As the measured value of temperature and humidity of the sensor was obtained, the measured value of temperature and humidity appeared in the thermohygrostat was taken at the same time. Comparing the average measured values of temperature and humidity measured at each six zones with the average values of the thermo-hygrostat results in a difference of 2.71℃ in temperature and 21.5% in humidity. The measured temperature and humidity of PET Gantry is out of domestic quality control range. According to the results of the study, if there is continuous change in temperature and humidity in the future, the aging of the scintillator mounted in the PET Gantry is expected to be aging, so it is necessary to find a way to properly maintain the temperature and humidity inside the Gantry structure.

• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.467-475
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• 2020

The purpose of this study is to assess doses to ¹⁸F-FDG, a radioactive drug, during PET examinations, to alleviate anxiety about radiation in patients and carers, to minimize the indiscriminate examination progress caused by medical institution personnel and space clearance problems, and health examination. The dose assessment was measured using a thermo-fluorescent dosimeter (TLD) and an electronic personal dosimeter (EPD) at the location of the cervical (hypothyroid), thorax (heart), and lower abdomen (breeding line) which are the three highest tissue areas of the radiation tissue weighting. In addition, spatial dose rates and radioactivity in urine were measured using GM counters and ion boxes. The results are as follows: First, the personal dosimeter TLD was measured 0.0425±0.0277 mSv in the cervical region, 0.0440±0.0386 mSv in the thorax and 0.0485±0.0436 mSv in the lower abdomen, with little difference in the heart dose depending on radiation sensitivity. The EPD was measured at 0.942±0.141 mSv/h immediately after the cervical position, and 0.192±0.031 mSv/h after 120 minutes. Immediately after the thorax position, 0.516±0.085 mSv/h, 120 minutes later 0.128±0.040 mSv/h. Immediately after the lower abdomen position, 0.468±0.091 mSv/h, and after 120 minutes 0.105±0.021 mSv/h were measured. The spatial dose rate at the GM counter was measured immediately at 0.041±0.005 mSv/h, 120 minutes later at 0.014±0.002 mSv/h. The radioactivity in urine using ion chamber was measured at 0.113±0.24 MBq/cc after 60 minutes and 0.063±0.13 MBq/cc after 120 minutes. As a result, ¹⁸F-FDG should be administered, dose re-evaluated two hours after the PET test is completed, and caregivers should be avoided. In addition, it is deemed necessary to provide patients and carers with sufficient explanations and expected values of exposure dose to avoid reckless testing. It is hoped that the data tested in this study will help patients and families relieve anxiety about radiation, and that the radiation workers' exposure management system and institutional improvements will contribute to the development of medical radiation.

• Pediatric Infection and Vaccine
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• v.5 no.1
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• pp.121-127
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• 1998

Purposes : This study was performed to evaluate the seropositivities and levels of term pregnant women and their neonates, and the transplacental transfer rate of maternal Epstein-Barr Virus-specific IgG(VCA IgG and EBNA IgG) from term pregnant women to their neonates. Subjects and Methods : During Jan. 1, 1997 to Mar. 31. 1997, we collected the 42 pairs of sera from pregnant women and umbilical cord of their neonates in Korea University Ansan Hospital. The serum levels of VCA IgG and EBNA IgG were measured by the ELISA method. Results : 1) The seropositivities of VCA IgG were 100% in mothers and neonates. There was no statistical difference of mean VCA IgG levels between mothers and neonates. There was significant correlation of VCA IgG levels between maternal sera and neonatal umbilical cord sera(correlation coefficient r=0.5214, P<0.001). 2) The seropositivities of EBNA IgG were 100% in mothers and neonates. There was no significant difference of the mean EBNA IgG levels between mothers and neonates. There was significant correlation of EBNA IgG levels between maternal sera and neonatal umbilical cord sera (correlation coefficient r=0.7244, P<0.001). 3) There was no correlation between VCA IgG and EBNA IgG levels of maternal sera. Conclusion : Seropositivities of EBV CA IgG and EBNA IgG of term-pregnant women and their neonates were 100% and no significant differences of antibody levels were found in two groups. It seems that EBV Antibody levels in Korean mothers and neonates were high enough to protect primary EBV infection during early infancy.

• Journal of Preventive Medicine and Public Health
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• v.42 no.2
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• pp.89-95
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• 2009

Objectives : To assess the protective effects of wearing protective devices among the residents and volunteers who participated in the cleanup of the Hebei Spirit oil spill. Methods : A total of 288 residents and 724 volunteers were surveyed about symptoms, whether they were wearing protective devices and potential confounding variables. The questionnaires were administered from the second to the sixth week following the accident. Spot urine samples were collected and analyzed for metabolites of 4 volatile organic compounds(VOCs), 2 polycyclic aromatic hydrocarbons(PAHs), and 6 heavy metals. The association between the wearing of protective devices and various symptoms was assessed using a multiple logistic regression adjusted for confounding variables. A multiple generalized linear regression model adjusted for the covariates was used to test for a difference in least-square mean concentration of urinary biomarkers between residents who wore protective devices and those who did not. Results : Thirty nine to 98% of the residents and 62-98% of volunteers wore protective devices. Levels of fatigue and fever were higher among residents not wearing masks than among those who did wear masks(odds ratio 4.5; 95% confidence interval 1.23-19.86). Urinary mercury levels were found to be significantly higher among residents not wearing work clothes or boots(p<0.05). Conclusions : Because the survey was not performed during the initial high-exposure period, no significant difference was found in metabolite levels between people who wore protective devices and those who did not, except for mercury, whose biological half-life is more than 6 weeks.

• Journal of radiological science and technology
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• v.35 no.4
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• pp.335-343
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• 2012

Intensity-modulated radiotherapy(IMRT) have the ability to provide better dose conformity and sparing of critical normal tissues than three-dimensional radiotherapy(3DCRT). Especially, with the benefit of health insurance in 2011, its use now increasingly in many modern radiotherapy departments. Also the use of linear accelerator with high-energy photon beams over 10 MV is increasing. As is well known, these linacs have the capacity to produce photonueutrons due to photonuclear reactions in materials with a large atomic number such as the target, flattening filters, collimators, and multi-leaf collimators(MLC). MLC-based IMRT treatments increase the monitor units and the probability of production of photoneutrons from photon-induced nuclear reactions. The purpose of this study is to quantitatively evaluate the dose of photoneutrons produced from 3DCRT and IMRT technique for Rando phantom in cervical cancer. We performed the treatment plans with 3DCRT and IMRT technique using Rando phantom for treatment of cervical cancer. An Rando phantom placed on the couch in the supine position was irradiated using 15 MV photon beams. Optically stimulated luminescence dosimeters(OSLD) were attached to 4 different locations (abdomen, chest, head and neck, eyes) and from center of field size and measured 5 times each of locations. Measured neutron dose from IMRT technique increased by 9.0, 8.6, 8.8, and 14 times than 3DCRT technique for abdomen, chest, head and neck, and eyes, respectively. When using IMRT with 15 MV photonbeams, the photoneutrons contributed a significant portion on out-of-field. It is difficult to prevent high energy photon beams to produce the phtoneutrons due to physical properties, if necessary, It is difficult to prevent high energy photon beams to produce the phtoneutrons due to physical properties, if necessary, it is need to provide the additional safe shielding on a linear accelerator and should therefore reduce the out-of-field dose.

• Journal of radiological science and technology
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• v.37 no.2
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• pp.125-134
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• 2014

This study is to provide basic information regarding photoneutron doses in terms of radiation treatment techniques and the number of portals in intensity-modulated radiation therapy (IMRT) by measuring the photoneutron doses. Subjects of experiment were 10 patients who were diagnosed with prostate cancer and have received radiation treatment for 5 months from September 2013 to January 2014 in the department of radiation oncology in S hospital located in Seoul. Thus, radiation treatment plans were created for 3-Dimensional Conformal Radiotherapy (3D-CRT), Volumetric-Modulated Arc Radiotherapy (VMAT), IMRT 5, 7, and 9 portals. The average difference of photoneutron dose was compared through descriptive statistics and variance analysis, and analyzed influence factors through correlation analysis and regression analysis. In summarized results, 3D-CRT showed the lowest average photoneutron dose, while IMRT caused the highest dose with statistically significance (p <.01). The photoneutron dose by number of portals of IMRT was $4.37{\pm}1.08mSv$ in average and statistically showed very significant difference among the number of portals (p <.01). Number of portals and photoneutron dose are shown that the correlation coefficient is 0.570, highly statistically significant positive correlation (p <.01). As a result of the linear regression analysis of number of portals and photoneutron dose, it showed that photoneutron dose significantly increased by 0.373 times in average as the number of portals increased by 1 stage. In conclusion, this study can be expected to be used as a quantitative basic data to select an appropriate IMRT plans regarding photoneutron dose in radiation treatment for prostate cancer.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.253-260
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• 2005

Mitotic centromere-associated kinesin (MCAK), which is a member of the Kin I (internal motor domain) subfamily of kinesin-related proteins, is known to play a role in mitotic segregation of chromosome during M phase of the cell cycle. In the present study, we have produced a rat polyclonal antibody using human MCAK (HsMCAK) expressed in E. coli as the antigen. The antibody specifically recognized the HsMCAK protein (81 kDa), and could detect its nuclear localization in human Jurkat T cells and 293T cells by Western blot analysis. The specific stage of the cell cycle was obtained through blocking by either hydroxyl urea or nocodazole and subsequent releasing from each blocking for 2, 4, and 7 h. While the protein level of HsMCAK reached a maximum level in the S phase with slight decline in the $G_{2}-M$ phase, the electrophoretic mobility shift from $p81^{MCAK}\;to\;p84^{MCAK}$ began to be induced in the late S phase and reached a maximum level in the $G_{2}/M $ phase, and then it disappeared as the cells enter into the $G_{1}$ phase. Immunocytochemical analysis revealed that HsMCAK protein localized to centrosome and nucleus at the interphase, whereas it appeared to localize to the spindle pole, centromere of the condensed mitotic DNA, spindle fiber, or midbody, depending on the specific stage of the M phase. These results demonstrate that a rat polyclonal antibody raised against recombinant HsMCAK expressed in E. coli specifically detects human MCAK, and indicate that the electrophoretic mobility shift from $p81^{MCAK}\;to\;p84^{MCAK}$, which may be associated with its differential intracellular localization during the cell cycle, fluctuates with a maximum level of the shift at the $G_{2}-M$ phase.

• Journal of Life Science
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• v.26 no.12
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• pp.1431-1437
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• 2016

Sorghum bicolor L. is one of the important minor cereals in Asia, Africa, and the central United States, and it is considered a rich source of polyphenols, flavonoids, and dietary fiber. However, there is a lack of data on the anti-cancer activity of Sorghum in prostate cancer cells and immune activity in macrophages. This study aims to investigate the potential effects of an ethanol extract of S. bicolor L. (SE) on inducing apoptosis in RC-58T/h/SA#4 cells and immunomodulatory activity in RAW 264.7 cells. SE significantly inhibited the viability of RC-58T/h/SA#4 primary prostate cancer cells in a dose-dependent manner. The morphology of RC-58T/h/SA#4 cells treated with SE was shrunken and involved the formation of an apoptotic body and nuclear condensation. In addition, SE markedly activated caspase-8, -9, and -3; increased the protein levels of Bax, p53, cleaved PARP, and cytosolic cytochrome c; and decreased Bcl-2 protein expression. Furthermore, the inhibition of caspases in RC-58T/h/SA#4 cells with z-VAD-fmk attenuated SE-induced cell growth inhibition. The production of nitric oxide (NO) was also elevated by SE treatment, as revealed by immune response parameters. These results suggest that SE inhibits growth and induces apoptosis in primary human prostate cancer cells in a caspase-dependent manner, and it modulates the immune functions in macrophages. Therefore, Sorghum bicolor L. may be used as a functional food to prevent prostate cancer and enhance immune activity.

• Journal of Life Science
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• v.30 no.2
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• pp.211-220
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• 2020

The activity of CAR can be regulated not only by ligand binding but also by phosphorylation of regulatory factors involved in extracellular signaling pathways, cross-talk interactions with transcription factors, and the recruitment, degradation, and expression of coactivators and corepressors. This regulation of CAR activity can in turn have effects on the control of diverse physiological homeostasis, including xenobiotic and energy metabolism, cellular proliferation, and apoptosis. CAR is phosphorylated by the ERK1/2 signaling pathway, which causes formation of a complex with Hsp-90 and CCRP, leading to its cytoplasmic retention, whereas phenobarbital inhibits ERK1/2, which causes dephosphorylation of the downstream signaling molecules, leading to the recruitment to CAR of the activated RACK-1/PP2A components for the dephosphorylation, nuclear translocation, and the transcriptional activation of CAR. Activated CAR cross-talks with FoxO1 to induce inhibition of its transcriptional activity and with PGC-1α to induce protein degradation by ubiquitination, resulting in the transcriptional suppression of PEPCK and G6Pase involved in gluconeogenesis. Regulation by CAR of lipid synthesis and oxidation is achieved by its functional cross-talks, respectively, with PPARγ through the degradation of PGC-1α to inhibit expression of the lipogenic genes and with PPARα through either the suppression of CPT-1 expression or the interaction with PGC-1α each to induce tissue-specific inhibition or stimulation of β-oxidation. Whereas CAR stimulates cellular proliferation by suppressing p21 expression through the inhibition of FoxO1 transcriptional activity and inducing cyclin D1 expression, it suppresses apoptosis by inhibiting the activities of MKK7 and JNK-1 through the expression of GADD45B. In conclusion, CAR is involved in the maintenance of homeostasis by regulating not only xenobiotic metabolism but also energy metabolism, cellular proliferation, and apoptosis through diverse cross-talk interactions with extracellular signaling pathways and intracellular regulatory factors.

• Journal of Life Science
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• v.30 no.4
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• pp.343-351
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• 2020

Sorbus commixta Hedl. has traditionally been used as a remedy for cough, asthma, and other bronchial disorders. In this study, three major triterpenoids-lupeol, β-sitosterol, and ursolic acid and a coumarin, scopoletin, were isolated from a CHCl₃-soluble fragment of the bark of S. commixta. Their structures were identified by spectroscopic analyses, including mass spectrometry (MS), 1D-, and 2D- nuclear magnetic resonance spectroscopy (NMR), as well as by comparing the data with data reported in the literature. Scopoletin was isolated from this plant for the first time. It is a nutraceutical compound contained in many plants that has been reported to exert diverse biological activities, including anti-inflammatory effects. This study examined the inhibitory effect of scopoletin on TNF-α-induced vascular endothelial inflammation. Unlike the marginal impact of other compounds against low-density lipoprotein (LDL) oxidation and vascular endothelial inflammation, scopoletin showed remarkable activity on LDL oxidation (IC₅₀ = 10.2 μM) and exerted vascular anti-inflammatory effects in EA.hy926 human endothelial cells activated by TNF-α. It suppressed the expression of adhesion molecules, such as ICAM-1, VCAM-1, and E-selectin, and blocked the adhesion between THP-1 monocytes and EA. hy926 endothelial cells. It also inhibited TNF-α-induced NF-κB translocation from the cytosol to the nucleus. Moreover, IκBα phosphorylation, which was increased by TNF-α treatment, was reduced after treatment with scopoletin. Thus, scopoletin inhibited TNF-α-induced vascular inflammation in endothelial cells by suppressing the NF-κB signaling pathway. These results demonstrate that owing to its anti-inflammatory activity in the vascular endothelium, scopoletin has the potential to inhibit atherosclerosis development.