• Radiation Oncology Journal
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• v.19 no.1
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• pp.66-73
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• 2001

Purpose : For the research of Boron Neutron Capture Therapy (BNCT), fast neutrons generated from the MC-50 cyclotron with maximum energy of 34.4 MeV in Korea Cancer Center Hospital were moderated by 70 cm paraffin and then the dose characteristics were investigated. Using these results, we hope to establish the protocol about dose measurement of epi-thermal neutron, to make a basis of dose characteristic of epi-thermal neutron emitted from nuclear reactor, and to find feasibility about accelerator-based BNCT. Method and Materials : For measuring the absorbed dose and dose distribution of fast neutron beams, we used Unidos 10005 (PTW, Germany) electrometer and IC-17 (Far West, USA), IC-18, ElC-1 ion chambers manufactured by A-150 plastic and used IC-l7M ion chamber manufactured by magnesium for gamma dose. There chambers were flushed with tissue equivalent gas and argon gas and then the flow rate was S co per minute. Using Monte Carlo N-Particle (MCNP) code, transport program in mixed field with neutron, photon, electron, two dimensional dose and energy fluence distribution was calculated and there results were compared with measured results. Results : The absorbed dose of fast neutron beams was $6.47\times10^{-3}$ cGy per 1 MU at the 4 cm depth of the water phantom, which is assumed to be effective depth for BNCT. The magnitude of gamma contamination intermingled with fast neutron beams was $65.2{\pm}0.9\%$ at the same depth. In the dose distribution according to the depth of water, the neutron dose decreased linearly and the gamma dose decreased exponentially as the depth was deepened. The factor expressed energy level, $D_{20}/D_{10}$, of the total dose was 0.718. Conclusion : Through the direct measurement using the two ion chambers, which is made different wall materials, and computer calculation of isodose distribution using MCNP simulation method, we have found the dose characteristics of low fluence fast neutron beams. If the power supply and the target material, which generate high voltage and current, will be developed and gamma contamination was reduced by lead or bismuth, we think, it may be possible to accelerator-based BNCT.

• Journal of Food Hygiene and Safety
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• v.35 no.3
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• pp.225-233
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• 2020

By the standards and specifications for hygiene products, three test methods for formaldehyde are specified for each item type of hygiene product. After derivatization using acetylacetone and 2,4-dinitrophenylhydrazine (2,4-DNPH), formaldehyde is analyzed by spectrophotometer and high-performance liquid chromatography (HPLC). Validation of the three test methods was performed on tissue, diaper lining and waterproof layer, and panty liner products. The results of linearity (R²), limit of detection (LOD), limit of quantification (LOQ), recovery rate (%) and reproducibility (%), showed that all three methods are suitable for analyzing formaldehyde in hygiene products. After derivatization with 2,4-DNPH and cetylacetone, formaldehyde was analyzed at 0, 3, 6, 9, 24 and 48 hours by HPLC. Formaldehyde derivatized with 2,4-DNPH showed no statistically significant change in formaldehyde peak area over time (P>0.05). But, acetylacetone-derivatizated formaldehyde showed a negative correlation coefficient (r) over time (P<0.01). We investigated the residual amounts of formaldehyde in 205 hygiene products distributed in Busan. Among 74 disposable diaper products tested, 73 had low concentrations of formaldehyde (0.13-29.87 mg/kg). Moreover, formaldehyde was not detected in any of 78 tissue, 27 disposable paper towel, 12 disposable dishcloth, 7 paper cup, one brand of paper straw and 6 disposable napkin products.

• Geophysics and Geophysical Exploration
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• v.10 no.1
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• pp.98-109
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• 2007

Over the last twenty years, farmers in Western Australia have begun to change land management practices to minimise the effects of salinity to agricultural land. A farm plan is often used as a guide to implement changes. Most plans are based on minimal data and an understanding of only surface water flow. Thus farm plans do not effectively address the processes that lead to land salinisation. A project at Broomehill in the south-west of Western Australia applied an approach using a large suite of geospatial data that measured surface and subsurface characteristics of the regolith. In addition, other data were acquired, such as information about the climate and the agricultural history. Fundamental to the approach was the collection of airborne geophysical data over the study area. This included radiometric data reflecting soils, magnetic data reflecting bedrock geology, and SALTMAP electromagnetic data reflecting regolith thickness and conductivity. When interpreted, these datasets added paddock-scale information of geology and hydrogeology to the other datasets, in order to make on-farm and in-paddock decisions relating directly to the mechanisms driving the salinising process. The location and design of surface-water management structures such as grade banks and seepage interceptor banks was significantly influenced by the information derived from the airborne geophysical data. To evaluate the effectiveness ofthis planning., one whole-farm plan has been monitored by the Department of Agriculture and the farmer since 1996. The implemented plan shows a positive cost-benefit ratio, and the farm is now in the top 5% of farms in its regional productivity benchmarking group. The main influence of the airborne geophysical data on the farm plan was on the location of earthworks and revegetation proposals. There had to be a hydrological or hydrogeological justification, based on the site-specific data, for any infrastructure proposal. This approach reduced the spatial density of proposed works compared to other farm plans not guided by site-specific hydrogeological information.

• Tuberculosis and Respiratory Diseases
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• v.48 no.2
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• pp.246-259
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• 2000

Background: As one of the etiologies of acute respiratory distress syndrome(ARDS), sepsis is one of the morbid causes of this cryptogenic malady. Even though many documents on the role of endotoxin(ETX) in the pathogenesis of ARDS have been issued, still the underlying mechanism associated with oxidative stress and activation of $PLA_2$ has been controversial. In the present study, the role of phospholipase $A_2(PLA_2)$ in the neutrophilic respiratory burst, which is presumed to cause acute lung injury during sepsis, was probed. Method: In glutathione-depleted Sprague-Dawley rats, lung leak, infiltration of neutrophils, $PLA_2$ activity and lipid peroxidation in the lung were measured after intratracheal instillation of endotoxin(delete). In addition, gamma glutamyl transferase(GGT) activity and the amount of pulmonary surfactant were measured. Morphologically, the changes in ultrastructure and cytochemical demonstration of oxidants were presented to confirm the neutrophilic oxidative stress and to elucidate the effects of $PLA_2$ activation on(delete) oxidative stress. Results: Instillation of ETX to glutathione-depleted rats intensified lung leak and lipid peroxidation when compared with non-glutathione depleted rats treated with the endotoxin. Moreover, oxidative stress was confirmed by the assay of GGT and malondialdehyde. Functionally, the depletion of glutathione altered the secretion of pulmonary surfactant from alveolar type II cells. Ultrastructurally and cytochemicaliy, oxidative stress was also confirmed after treatment of with ETX and diethylmaleate(DEM). Conclusion: The endotoxin-induced acute lung injury was mediated by oxidative stress, which in turn was provoked by the neutrophilic respiratory burst. The activation of $PLA_2$ in the lung seems to playa pivotal role in the oxidative stress of the lung.

• Clinical and Experimental Pediatrics
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• v.49 no.6
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• pp.617-622
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• 2006

Purpose : High-Sensitivity C-reactive protein(hs-CRP) has been recognized as a very useful and sensitive predictor of the future risk of myocardial infarction. But the clinical significance of hs-CRP in children remains uncertain. To confirm the existence of obesity-induced vascular inflammation and the association between metabolic syndromes and elevation of CRP in children, we investigated the relationship among CRP, obesity, blood pressure(BP), and serum lipids in schoolboys. Methods : Twenty-eight obese(BMI $29.61{\pm}3.29kg/m^2$) and 93 non-obese(BMI $18.99{\pm}2.21kg/m^2$) boys aged 14 years were examined. Serum CRP levels was measured by the high sensitive latex turbidimetric immunoassay and subjects with CRP levels below 0.3 mg/dL were adopted to avoid the influence of acute infection. Results : Obese children had significantly higher hs-CRP levels than their non-obese group($0.104{\pm}0.075$ vs. $0.054{\pm}0.005mg/dL$). In the obese group, BMI, systolic blood pressure, diastolic blood pressure, apolipoprotein B, atherogenic index, and triglyceride were significantly higher than in nonobese. The BMI, diastolic blood pressure, apolipoprotein E, atherognic index, and triglyceride showed positive correlation with log CRP by simple regression. Multiple regression analysis indicated that BMI and apolipoprotein E were strongly related to CRP. Conclusion : This study revealed that obese children tended to have higher levels of serum hsCRP, BP elevation and dyslipidemia than the control group and that BMI and apolipoprotein E were strongly related to CRP. These results indicate that obesity related metabolic syndrome can be developed in children.

• Clinical and Experimental Pediatrics
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• v.45 no.3
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• pp.302-310
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• 2002

Purpose : X-linked agammaglobulinemia(XLA) is an immunodeficiency caused by abnormalities in Bruton's tyrosine kinase(Btk), and is characterized by a deficiency of peripheral blood B cells. We studied cytoplasmic expression of Btk protein and analyzed the Btk gene in peripheral blood mononuclear cells(PBMC) from three XLA families in Korea. Methods : Heparinized venous blood samples were collected from four XLA patients and additional family members in three unrelated XLA families. Mononuclear cells were separated from their blood and the intracellular Btk protein was characterized by a flow cytometry. The mutation analysis was performed using direct sequencing. Results : Cytoplasmic expression of Btk protein in monocytes was not detected in the patients with XLA. We observed a novel deletion and two point mutations within introns(intron 1 and intron 18) resulting in alternative splicings. In XLA family 2, a 980 bp deletion(from intron 9+191 T to intron 10-215 C) including exon 10 was found in patient P2. He was the only sporadic case in this study, because his mother and brother showed a normal Btk expression by flow cytometry. Conclusion : These identified genetic alterations support the molecular heterogeneity of Btk gene in XLA disease. Additionally, by means of flow cytometric analysis, we diagnosed three hypogammaglobulinemia patients as XLA. Advancements in diagnostic methods has facilitated a prompt and definite diagnosis of this disease.

• Neonatal Medicine
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• v.16 no.2
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• pp.197-204
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• 2009

Purpose: The objective of this study was to describe the frequency of hepatobiliary dysfunction (HD) at our hospital and determine the possible risk factors and complications associated with the development of HD in very low birth weight infants (VLBWI) treated with parenteral nutrition (PN). Methods: A retrospective study of VLBWI (n=92) that required PN between 2004 and 2008 in the NICU at the Bucheon St. Marys Hospital of Catholic University was performed. HD was defined by a direct bilirubin (DB) >2 mg and a transaminase of 60 IU/L defined cholestasis and liver injury. Groups I, II, and III were limited to cases of cholestasis, liver injury without cholestasis, and no abnormalities, respectively. The VLBWI were compared to each other. Results: Thirty-six subjects (39.1%) had cholestasis and 51 (55.4%) had liver injury. In addition, 36 (39.1%), 19 (20.7%), and 37 (40.2%) subjects were classified as groups I, II, and III, respectively. The three groups showed significant differences in gestational age, 1- and 5-minute Apgar scores, use of surfactant, duration of parenteral nutrition, frequency of RBC transfusions, bronchopulmonary dysplasia (BPD), and patent ductus arteriosus (PDA) (P<0.05). The multiple regression analysis with cholestasis as the dependent variable, showed a significant correlation with gestational age, use of surfactant, frequency of RBC transfusions, and PDA. Conclusion: Various factors, such as birth weight, gestational age, 1- and 5-minute Apgar scores, use of surfactant for respiratory distress syndrome (RDS), frequency of RBC transfusions, BPD, and PDA may be related to hepatobiliary dysfunction in VLBWI treated with PN.

• Tuberculosis and Respiratory Diseases
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• v.40 no.4
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• pp.378-383
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• 1993

Background: In recent reports, it has been reported that increased coagulation and decreased fibrinolytic activity has been responsible for abnormal fibrin turnover in exudative pleural effusion. In the cases of empyema, the fibrinopurulent stage is characterized by the fibrin deposition resulting in formation of limiting membranes in the visceral and parietal pleura. Recently attention has been focused on intrapleural fibrinolytic therapy capable of removing intrapleural fibrin deposits by urokinase (UK) in the treatment of empyema. However, these clinical trials have provided the clinical evidences for resolution of pleural loculation after intrapleural urokinase injection (UK-injection), the profiles of fibrinolytic activity following the treatment were still not investigated. Therefore in order to demonstrate the fibrinolytic evidences behind the clinical efficacy of intracavitary UK-injection, we examined intrapleural plasminogen activator activity (PA-activity) and D-dimer (D-Di) concentrations before and after each repeated UK-injection into the pleura in subjects with loculated empyema cavity. Methods: In a group of 14 patients with multiple loculated empyema cavity, PA-activity and D-Di concentrations were measured before and after repeated UK-injection. One hundred thousand IU of UK was injected at each time and all sujects had at least two times of UK injection accoring to clinical decisions. Nine out of 14 sujects had three times of UK-injection. Results: The mean (${\pm}SE$) PA-activity prior to treatemnt was $10.5{\pm}7.0$ and it was increased to $91.9{\pm}27.0,\;432.3{\pm}177.1,\;170.0{\pm}85.3$ IU tPA/ml after first, second and third time of UK-injection respectively (p<0.01). D-Di concentrations were also increased from $4.16{\pm}1.06{\times}10^5$ to $9.62{\pm}1.54{\times}10^5,\;12.31{\pm}1.89{\times}10^5,\;8.54{\pm}1.56{\times}10^5$ ng/ml in the same order as above (p<0.05). Conclusion: The suppressed fibrinolytic activity in the empyema cavity get removed sinificantly after inrracavitary injection of urokinase by generation of additional intrapleural plasmin.

• Tuberculosis and Respiratory Diseases
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• v.45 no.5
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• pp.942-952
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• 1998

The aim of this study was to evaluate spontaneous and LPS stimulated proinflammatory cytokines and chemokine release of alveolar macrophages in the patients with pulmonary tuberculosis and healthy individuals, as a control. Alveolar macrophages recovered from bronchoalveolar lavage fluids were cultured with or without LPS 0.1, 1, or 10 ${\mu}g/ml$ for 24 and 48 hours in 37C, 5% CO2. TNF-$\alpha$, IL-1$\beta$, IL-6 and IL-8 amount were evaluated using ELISA kit from the supernatants. There were a significant increase in the spontaneous 24 hours release of TNF-$\alpha$ and IL-6 from the involved segments of tuberculosis patients compared with uninvolved segments and normal control There were also increasing trends of release of them after LPS stimulation in involved segments, but not significant. IL-1$\beta$ and IL-8 were not evaluated from the involved segments of tubeculosis and there were not significant differences of them between uninvolved segments of tuberculosis and normal control. It is concluded that cytokine release of alveolar macrophages in the pulmonary tuberculosis was markedly increased, and it was localized to the alveolar macrophages from the involved segments.

• Tuberculosis and Respiratory Diseases
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• v.60 no.6
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• pp.625-630
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• 2006

Background: Pulmonary hypertension in COPD patients is the result of a direct effect of tobacco smoke on the intrapulmonary vessels with the abnormal production of the mediators that control vasoconstriction, vasodilatation, and vascular cell proliferation, which ultimately lead to aberrant vascular remodeling and physiology. COPD patients are prone to the developmint of an acute and chronic thromboembolism with an elevation of the plasma procoagulant and fibrinolytic markers However, the roles of the coagulation and fibrinolysis system on the right ventricular dysfunction in COPD patients are not well defined. We examined the alteration of the coagulation and fibrinolysis system in COPD patients according to the right ventricular function measured using cardiac multidetector computed tomography (MDCT). Methods: The right ventricular ejection fraction (RVEF) was measured using cardiac MDCT in 26 patients who were diagnosed with COPD according to the definition of the GOLD guideline. The plasma level of thrombin antithrombin (TAT) and plasminogen activator inhibitor (PAI)-1 were measured using an enzyme linked immunoassay. Results: The plasma TAT was markedly elevated in COPD patients ($10.5{\pm}19.8{\mu}g/L$) compared with those of the control ($3.4{\pm}2.5{\mu}g/L$) (p<0.01). However, the plasma PAI-1 in COPD patients ($29.6{\pm}20.7ng/mL$) was similar to that in the controls. The plasma TAT showed a significant inverse relationship with the RVEF measured by the cardiac MDCT in COPD patients (r=-0.645, p<0.01). However, the plasma PAI-1 did not show a relationship with the RVEF (r=0.022, p=0.92). Conclusion: These results suggest that the coagulation system in COPD patients is markedly activated, and that the plasma level of TAT might be a marker of a right ventricular dysfunction in COPD patients.