• Korean Journal of Digital Imaging in Medicine
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• v.14 no.2
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• pp.23-31
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• 2012

There are AEC mode and fix mode to exposure when the whole spine antero-posterior radiography is done by using DR equipment. This study compared the utility of fix mode to AEC mode, by evaluating organ dose and effective dose and by examining the quality of radiographic image. GE DEFINIUM 8000 and ART-200X Rando Phantom manufactured by Flukebiometical were used for this study. The Rando phantom was set in front of wall detector of X-rays equipment. AEC mode was set at 80kVp and Fix mode was set at 80kVp, 25mAs, 32mAs, 40mAs, and 50mAs. Whole spine AP image were aquired by combining C, T-L and L-S spine images obtained through 3 exposures. When obtaining C, T-L and L-S spine images, were checked for Air kerma (mGy) value calculated by UNFORS Xi meter attached at the phantom surface of center of radiation field. The effective and organ doses were compared by PCXMC program (PC-Based Monte Carlo Program). The quality of obtained radiographic image was evaluated visually by 3 radiologists using resolution chart. When the effective doses was calculated based on tissue weighting factor of ICRP-103, 1.278mSv was measured by AEC mode, and Fix mode measured 0.405mSv at 25mAs, 0.518mSv at 32mAs, 0.649mSv at 40mAs, and 0.810mSv at 50mAS. In addition, the organ dose measured with esposure at 25mAs by Fix mode was almost equivalent to the organ dose by AEC mode, at the esophagus, thyroid, oral mucosa, salivaly glands located at the cervical spine part, while the organ dose by Fix mode was in general lower than the organ dose by AEC mode at the other organs. When Fix mode at 32mAs, 40mAs, and 50mAs was compared to AEC mode for organ dose in 26 organs, AEC mode had higher measurement in 21 organs but not for than brain, trachea, thyroid, oral mucosa, and salivaly glands which are located at the cervical spine part. The image quality evaluated by resolution test chart was much higher with AEC mode than the quality with Fix mode at all exposure conditions. However, while the image quality of cervical spine exposured at 50mAs by Fix mode was lower than the quality of AEC mode, thoraco-lumbar spine and lumbo-sacral spine were calculated and the quality was similar to AEC mode. Scoliosis occurs mainly at thoraco-lumbar and lumbo-sacral spine, not at cervical spine. Compared to AEC mode, Using the appropriate protocol (80kVp, 50mAs) of fix mode for whole spine AP radiography was thought to be useful because the image quality of the thoraco-lumar and lumbo-sacral spine was similar on AEC mode, Also organ and effective doses can be decreased with Fix mode. Therefore, It is considered that fix mode can be used properly with AEC mode for whole spine AP radiography when considering patient's body posture.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.285-295
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• 2023

With the development of technology, efforts to reduce the exposure dose received by patients in CT scans are continuing with the development of new reconstruction techniques. Recently, deep learning reconstruction techniques have been developed to overcome the limitations of repetitive reconstruction techniques. This study aims to evaluate the usefulness of images according to reconstruction techniques in pediatric chest CT images. Patient study conducted a study on 85 pediatric patients who underwent chest CT scan at P-Hospital in Gyeongsangnam-do from January 1, 2021 to December 31, 2022. The phantom used in the Phantom Study is the Pediatrics Whole Body Phantom PBU-70. After the test, the images were reconstructed with FBP, ASIR-V (50%) and DLIR (TF-Medium, High), and the images were evaluated by obtaining SNR and CNR values by setting ROI of the same size. As a result, TF-H of deep learning reconstruction techniques had the lowest noise value compared to ASIR-V (50%) and TF-M in all experiments, and SNR and CNR had the highest values. In pediatric chest CT scans, TF images with deep learning reconstruction techniques were less noisy than ASiR-V images with adaptive statistical iterative reconstruction techniques, CNR and SNR were higher, and the quality of images was improved compared to conventional reconstruction techniques.

• Clinical and Experimental Pediatrics
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• v.53 no.4
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• pp.481-487
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• 2010

Purpose: Recently many studies show early exposure during childhood growth to endotoxin (lipopolysaccharides, LPS) and/or early exposure to allergens exhibit important role in development of allergy including bronchial asthma. The aim of this study was to evaluate the role of endotoxin and allergen exposure in early life via the airways in the pathogenesis of allergic airways inflammation and airway hyperresposiveness (AHR) in mouse model of asthma. Methods: Less than one week-old Balb/c mice was used. Groups of mice were received either a single intranasal instillation of sterile physiologic saline, 1% ovalbumin (OVA), LPS or $1.0{\mu}g$ LPS in 1% OVA. On 35th day, these animals were sensitized with 1% OVA for 10 consecutive days via the airways. Animals were challenged with ovalbumin for 3 days on 55th days, and airway inflammation, hyperresponsiveness, and cytokine expression were assessed. Measurements of airway function were obtained in unrestrained animals, using whole-body plethysmography. Airway responsiveness was expressed in terms of % enhanced pause (Penh) increase from baseline to aerosolized methacholine. Lung eosinophilia, serum OVA-IgE and bronchoalveolar lavage (BAL) fluid cytokine levels were also assessed. ANOVA was used to determine the levels of difference between all groups. Comparisons for all pairs were performed by Tukey-Kramer honest significant difference test; $P$ values for significance were set to 0.05. Results: Sensitized and challenged mice with OVA showed significant airway eosinophilia and heightened responsiveness to methacholine. Early life exposure of OVA and/or LPS via the airway prevented both development of AHR as well as bronchoalveolar lavage fluid eosinophilia. Exposure with OVA or LPS also resulted in suppression of interleukin (IL)-4, 5 production in BAL fluid and OVA specific IgE in blood. Conclusion: These results indicate that antigen and/or LPS exposure in the early life results in inhibition of allergic responses to OVA in this mouse model of astham. Our data show that early life exposure with OVA and/or LPS may have a protective role in the development of allergic airway inflammation and development of allergen-induced airway responses in mouse model of asthma.

• Journal of Radiation Protection and Research
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• v.22 no.2
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• pp.103-109
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• 1997

Adult male rats were exposed to a whole body with a single dose of 1.0, 2.0, 3.0, 5.0, and 7.0 Gy. The animals were sacrificed 48, 72, 96 and 216 hours following exposure. A competitive enzyme linked immunosorbent assay(ELISA) with antigen immobilized on the solid phase has been developed to measure ceruloplasmin in rat serum and complete dose response curves. Ceruloplasmin was purified from the plasma of turpentine treated male rats. Coating of ceruloplasmin had more effectiveness in 10 mM Tris-HCI, 150 mM sodium chloride, pH 7.4 than in 50 mM carbonate/bicarbonate buffer, pH 9.6. The coating range for ceruloplasmin was $70{\sim}140ng$/well. Levels of ceruloplasmin increased to maximum on the $72{\sim}96$ hours after irradiation. Slope of between response and dose was greatest value 96 hours following irradiation. Normal ceruloplasmin levels were not recorded 216 hours following exposure. In 0.1 Gy irradiated group, levels of ceruloplasmin also increased to maximum on the $72{\sim}96$ hours following irradiation. The concentration of this protein remained significantly different from control value, 196 hours after exposure. Ceruloplasmin was identified as one of the major acute phase protein following irradiation and further studies about gene expression and regulation would be necessary for radiation protection.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.1
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• pp.21-28
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• 2007

The bioaccumulation of Pb and Cd dissolved in seawater was assessed measuring the concentrations recorded within blue mussel (Mytilus edulis) and oliver flounder (Paralichthys olivaceus) after two weeks exposure period. The Pb and Cd concentration within the whole body of two testing organisms increased according to the exposure concentrations, and the such tendency was clear specially from the mussel. Maximum metal concentration reached $5,260({\pm}70)\;{\mu}g/g$ for Pb reared under 5.0 mg/L Pb, $1,040({\pm}40)\;{\mu}g/g$ for Cd reared under 1.0 mg/L Cd in the mussel, and indicated that the bioaccumulation of Pb and Cd was directly related to the rearing medium concentrations. Bioconcentration factors (BCF) reached very high values for Pb (maximum value: $12,100{\pm}1,400$) in the mussel reared under lowest Pb concentration (0.01 mg/L). The BCF value for Cd in the mussel were also far higher at exposure to low Cd concentration than high Cd concentration. At higher external concentrations, the BCF for Cd and Pb declined. This demonstrated the ability of two testing organisms to rapidly uptake heavy metals particularly when exposed to low external concentration. The mean Pb concentration was slightly higher in the gill of mussel than in the digestive gland, while Cd showed a higher level in the digestive gland than in the gill.

• Journal of the Korean Institute of Gas
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• v.17 no.4
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• pp.18-25
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• 2013

It may occur health hazards or death by suffocation or acute poisoning in case of oxygen deficiency in ambient or exposure to harmful gas. As a part of accident prevention, we studied the change of activity and lethal dose by changing the concentration of several hazardous gas with inhalation exposure chamber and laboratory animals. We investigated the lethality and motility change during either the 4 hrs whole body exposure to oxygen, nitrogen, toluene, $H_2S$, CO and 48 recovery. As results, it is estimated that 5% oxygen concentration as lethal concentration and 5.5% as $LC_{50}$ (rat, 4 hrs) with statistics for dose-response. The results of lethality in oxygen deficient condition (approximately 6%), the lethalities were 40%, 20% with 20 ppm $H_2S$, 600 ppm CO respectively, and was not increased the lethality with 8% CO. Thus, it was confirmed that the $H_2S$, CO had influence to lethal dose, while toluene had low fluence.

• Progress in Medical Physics
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• v.2 no.2
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• pp.109-120
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• 1991

Total body irradiation is operated to irradicate malignant cells of bone marrow of patients to be treated with bone marrow transplantation. Field size of a linear accelerator or cobalt teletherapy unit with normal geometry for routine technique is too small to cover whole body of a patient. So, any special method to cover patient whole body must be developed. Because such environments as room conditions and machine design are not universal, some characteristic method of TBI for each hospital could be developed. At Seoul National University Hospital, at present, only a cobalt unit is available for TBI because source head of the unit could be tilted. When the head is tilted outward by 90$^{\circ}$, beam direction is horizontal and perpendicular to opposite wall. Then, the distance from cobalt source to the wall was 319 cm. Provided that the distance from the wall to midsagittal plane of a patient is 40cm, nominal field size at the plane(SCD 279cm) is 122cm$\times$122cm but field size by measurement of exposure profile was 130cm$\times$129cm and vertical profile was not symmetric. That field size is large enough to cover total body of a patient when he rests on a couch in a squatting posture. Assuming that average lateral width of patients is 30cm, percent depth dose for SSD 264cm and nominal field size 115.5cm$\times$115.5cm was measured with a plane-parallel chamber in a polystyrene phantom and was linear over depth range 10～20cm. An anthropomorphic phantom of size 25cm wide and 30cm deep. Depth of dose maximum, surface dose and depth of 50% dose were 0.3cm, 82% and 16.9cm, respectively. A dose profile on beam axis for two opposing beams was uniform within 10% for mid-depth dose. Tissue phantom ratio with reference depth 15cm for maximum field size at SCD 279cm was measured in a small polystyrene phantom and was linear over depth range 10～20cm. An anthropomorphic phantom with TLD chips inserted in holes on the largest coronal plane was bilaterally irradiated by 15 minute in each direction by cobalt beam aixs in line with the cross line of the coronal plane and contact surface of sections No. 27 and 28. When doses were normalized with dose at mid-depth on beam axis, doses in head/neck, abdomen and lower lung region were close to reference dose within $\pm$ 10% but doses in upper lung, shoulder and pelvis region were lower than 10% from reference dose. Particulaly, doses in shoulder region were lower than 30%. On this result, the conclusion such that under a geometric condition for TBI with cobalt beam as SNUH radiotherapy departement, compensators for head/neck and lung shielding are not required but boost irradiation to shoulder is required could be induced.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.569-588
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• 2013

The organic foods is the terminology calling the organic products, the organic livestock and the organic processing food. The value of organic food may be evaluated as the index of the nutrient content, the safety and the health promotion. The reason why consumers prefer the organic food in the market is because the value of health promotion to be obtained through its consumption is expected to be bigger than the expense according to the purchase of organic food. This study has the significance in developing the direct evaluation model like the human biomonitoring method. The hypothesis for this study is summarized, "If the metabolome of metabolic syndrome of decreases, the exposure of substance of health harm decreases, the number of hospital care decreases and the quality of life shall be improved if the organic food is incepted in the long term and the health care is managed well". The consumer's cooperative and the health consumer's cooperative select the experimental group of 100 persons and the comparative group of 100 persons in 5 areas in the whole country at the same time to verify this hypothesis. Its rate of change is compared and analyzed by measuring the blood and urine of each biomarkers such as the exposed agriculture pesticides, the nitrate in the body at intervals of 2 months for 1 year. Also, by letting participants in the experiment record the major activity such as the dietary intake and the exercise, etc., in the questionnaire and the performance evaluation form, the statistical analysis for the correlation of this with the metabolome, etc., is conducted. The time that is called minimum 1 year and a lot of expense are required to implement this model. Accordingly, the cooperative study by composing the consortium of the interdisciplinary and the interagency is desirable.

• Journal of Environmental Health Sciences
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• v.31 no.3
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• pp.227-233
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• 2005

This study was conducted to determine the endorcrine disruption effects of the several major pharmaceutical residues in water using adult Japanese medaka (Oryzias latipes). Four frequently used pharmaceuticals including caffeine, ketoconazole, acetaminophen, and diltiazem were investigated for the vitellogenin(Vtg) induction in the medaka using Western blotting and ELISA. $17\beta$,-estradiol was used as a positive control. Vtg was qualified and quantified through Western blot and ELISA. Following SDS gel electrophoresis, the dominant protein band was identified to molecular weight approximately 205 kDa in whole body samples of vitellogenic female. With female medaka exposed to $17\beta,-estradiol$, no significant difference in total protein induction was noted. In contrast, three to five day exposure of male fish to $17\beta,-estradiol$ resulted in $63.07\%o$, increase of total protein comparing to that of control males (p<0.01). Vtg induction in male fish was observed with all the test pharmaceuticals: At concentrations greater than 1ppm of diltiazem, 2 ppm of caffeine, 4 ppm of acetaminophen, and 10 ppm of ketoconazole, Vtg induction was monotonously increased in a dose dependent manner. This study is one of the first reports suggesting potential endocrine disruption mechanism of common human pharmaceutical products in aquatic ecosystem. Although the effect concentrations obtained from this investigation are environmentally unrealistically high, endocrine disruption should be considered as one of the important consequences of pharmaceutical pollution in aquatic environment, and warrants due attention in future researches.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.97-97
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• 2003

Embryonic stem (ES) cells, derived from preimplantation embryos, are able to differentiate into various types of cells consisting the whole body, or pluripotency. In addition to the plasticity, ES cells are expected to be different from terminally differentiated cells in very many ways, such as patterns of gene expressions, ability and response of the cells in confronting environmental stimulations, metabolism, and growth rate. As a model system to differentiate these two types of cells, human ES (hES, MB03) cells and terminally differentiated cells (HeLa), we examined the ability of these two types of cells in confronting a severe oxidative insult, that is $H_2 O_2$. Ratio of dying cells as determined by the relative amount of dye neutral red entrapped within the cells after the exposures. Cell death rates were not significantly different when either MB03 or HeLa were exposed up to 0.4 mM $H_2 O_2$. However, relative amount of dye entrapped within the cells sharply decreased down to 0.12% in HeLa cells when the cells were exposed to 0.8 mM $H_2 O_2$, while it was approximately 54% in MB03. Pretreatment of cells with BSO (GSH chelator) and measurement of GSH content results suggest that cellular GSH is the major defensive mechanism of hES cells. Induction of apoptosis in hES cell was confirmed by DNA laddering, induction of Bax, and chromatin condensation. In summary, hES cells 1) are extremely resistant to oxidative stress, 2) utilize GSH as a major defensive mechanism. and 3) experience apoptosis upon exposure to oxidative stress.