SeongJae Jang - Academia.edu (original) (raw)
Papers by SeongJae Jang
Radiation and Environmental Biophysics
Radiation dose estimations performed by automated counting of micronuclei (MN) have been studied ... more Radiation dose estimations performed by automated counting of micronuclei (MN) have been studied for their utility for triage following large-scale radiological incidents; although speed is essential, it also is essential to estimate radiation doses as accurately as possible for long-term epidemiological follow-up. Our goal in this study was to evaluate and improve the performance of automated MN counting for biodosimetry using the cytokinesis-block micronucleus (CBMN) assay. We measured false detection rates and used them to improve the accuracy of dosimetry. The average false-positive rate for binucleated cells was 1.14%; average false-positive and -negative MN rates were 1.03% and 3.50%, respectively. Detection errors seemed to be correlated with radiation dose. Correction of errors by visual inspection of images used for automated counting, called the semi-automated and manual scoring method, increased accuracy of dose estimation. Our findings suggest that dose assessment of the...
Nuclear Engineering and Technology
Journal of Radiation Research, 2019
The dicentric chromosome assay (DCA) is a well-established biodosimetry test to estimate exposure... more The dicentric chromosome assay (DCA) is a well-established biodosimetry test to estimate exposure to ionizing radiation. The Korea Institute of Radiological and Medical Sciences (KIRAMS) established a DCA protocol as a medical response to radiation emergencies in South Korea. To maintain its accuracy and performance, intercomparison exercises with Health Canada (HC) have been conducted; herein, we aimed to validate our capacity of DCA analysis based on those results. Blood samples irradiated at HC were shipped to KIRAMS to assess the irradiation dose to blinded samples using conventional DCA full scoring and triage-based techniques (conventional DCA scoring in triage mode and DCA QuickScan method). Actual doses fell within the 95% confidence intervals of dose estimates for 70–100% of the blinded samples in 2015–2018. All methods discriminated binary dose categories, reflecting clinical significance. This DCA can be used as a reliable radiation biodosimetry tool in preparation for ra...
Journal of radiation research, Jan 28, 2015
Two cases of hematological malignancies were reported in an industrial radiography company over a... more Two cases of hematological malignancies were reported in an industrial radiography company over a year, which were reasonably suspected of being consequences of prolonged exposure to ionizing radiation because of the higher incidence than expected in the general population. We analyzed chromosomal aberrations in the peripheral blood lymphocytes from the other workers who had been working under similar circumstances as the patients in the company. Among the subjects tested, 10 workers who belonged to the highest band were followed up periodically for 1.5 years since the first analysis. The aim of this study was to clarify pertinence of translocation analysis to an industrial set-up where chronic exposure was commonly expected. To be a useful tool for a retrospective biodosimetry, the aberrations need to be persistent for a decade or longer. Therefore we calculated the decline rates and half-lives of frequency for both a reciprocal translocation and a dicentric chromosome and compared...
... controls is that the operating point is oscillating around the MPP, even during sunny day whe... more ... controls is that the operating point is oscillating around the MPP, even during sunny day when irradiance and temperature are slowly varying ... Sang-Yong Kim, Sangsoo Park, Seong-Jae Jang, Gyeong-Hun Kim, Hyo-Ryong Seo, Minwon Park, Member, IEEE and In-Keun Yu ...
Journal of Biological Chemistry, 2008
Nuclear Engineering and Technology
Mutation research, 2021
Most blood components for transfusions are irradiated ex vivo to prevent transfusion-associated g... more Most blood components for transfusions are irradiated ex vivo to prevent transfusion-associated graft-versus-host disease (TA-GvHD); this irradiation can potentially affect the cytogenetic dose assessment of patients showing acute radiation syndrome (ARS) with bone marrow suppression or acute anaemia. Whole blood samples from five donors were irradiated with 0, 10 or 25 Gy γ-rays. The mitotic activity of each cultured blood sample was measured by calculating the mitotic index. A dicentric chromosome assay was used to evaluate the chromosomal aberrations and absorbed dose of blood lymphocytes. Mitogenic activity and scorable metaphase spreads were significantly decreased in the blood samples irradiated with 10 and 25 Gy (p < 0.001). Moreover, a significant increase in the mean scores of all types of chromosomal aberrations in the 10 Gy γ-irradiated samples was observed, with the estimated dose being 11.3 Gy (95% CI: 10.67-11.95 Gy); however, we were unable to estimate the exposure...
Mutation Research/Genetic Toxicology and Environmental Mutagenesis
International Journal of Radiation Biology
Purpose: In case of a mass-casualty radiological event, there would be a need for networking to o... more Purpose: In case of a mass-casualty radiological event, there would be a need for networking to overcome surge limitations and to quickly obtain homogeneous results (reported aberration frequencies or estimated doses) among biodosimetry laboratories. These results must be consistent within such network. Inter-laboratory comparisons (ILCs) are widely accepted to achieve this homogeneity. At the European level, a great effort has been made to harmonize biological dosimetry laboratories, notably during the MULTIBIODOSE and RENEB projects. In order to continue the harmonization efforts, the RENEB consortium launched this intercomparison which is larger than the RENEB network, as it involves 38 laboratories from 21 countries. In this ILC all steps of the process were monitored, from blood shipment to dose estimation. This exercise also aimed to evaluate the statistical tools used to compare laboratory performance. Materials and methods: Blood samples were irradiated at three different doses, 1.8, 0.4 and 0 Gy (samples A, C and B) with 4-MV X-rays at 0.5 Gy min À1 , and sent to the participant laboratories. Each laboratory was requested to blindly analyze 500 cells per sample and to report the observed frequency of dicentric chromosomes per metaphase and the corresponding estimated dose. Results: This ILC demonstrates that blood samples can be successfully distributed among laboratories worldwide to perform biological dosimetry in case of a mass casualty event. Having achieved a substantial harmonization in multiple areas among the RENEB laboratories issues were identified with the available statistical tools, which are not capable to advantageously exploit the richness of results of a large ILCs. Even though Zand U-tests are accepted methods for biodosimetry ILCs, setting the number of analyzed metaphases to 500 and establishing a tests' common threshold for all studied doses is inappropriate for evaluating laboratory performance. Another problem highlighted by this ILC is the issue of the dose-effect curve diversity. It clearly appears that, despite the initial advantage of including the scoring specificities of each laboratory, the lack of defined criteria for assessing the robustness of each laboratory's curve is a disadvantage for the 'one curve per laboratory' model.
Mutation Research/Genetic Toxicology and Environmental Mutagenesis
Nuclear Engineering and Technology
Disaster Medicine and Public Health Preparedness
This training session is organized by the Korea Institute of Radiological and Medical Sciences (K... more This training session is organized by the Korea Institute of Radiological and Medical Sciences (KIRAMS), which conducts practical training in medical treatments during nuclear disasters based on the international standards for radiation protection. The practical training began with the assumption that a large-scale earthquake had caused an on-site emergency at the Kori Nuclear Power Plant (NPP); the aim of this training was to enhance control of the command system, information sharing, confirmation of triage, and patient distribution during an emergency situation. In this training, our group (the Japanese team) participated in REM as a radiation emergency medical assistance team including doctors, nurses, radiologic technologists, and logistics personnel, and cooperated with Korea's radiation emergency medical assistance team. In this study, we briefly introduce the contents of REM 2017 and discuss how we can make use of it in future education on nuclear disaster response.
Journal of Radiological Protection
Industrial radiographers are exposed to relatively higher doses of radiation than other radiation... more Industrial radiographers are exposed to relatively higher doses of radiation than other radiation-exposed workers in South Korea. The objective of our study was to investigate the impact of specific occupational conditions on chromosome aberration frequency and evaluate dosimeter-wearing compliance of industrial radiographers in Korea. We studied individual and occupational characteristics of 120 industrial radiographers working in South Korea and evaluated the frequency of dicentrics and translocations in chromosomes to estimate radiation exposure. The association between working conditions and chromosome aberration frequencies was assessed by Poisson regression analysis after adjusting for confounding factors. Legal personal dosimeter-wearing compliance among workers was investigated by correlation analysis between recorded dose and chromosome aberration frequency. Daily average number of radiographic films used in the last 6 months was associated with dicentrics frequency. Workers performing site radiography showed significantly higher translocation frequency than those working predominantly in shielded enclosures. Correlation between chromosome aberration frequency and recorded dose was higher in workers in radiography occupation since 2012 (new workers) than other veteran workers. Our study found that site radiography could affect actual radiation exposure to workers. Controlling these working conditions and making an effort to improve personal dosimeterwearing compliance for veteran workers as well as new workers may be necessary to reduce radiation exposure as much as possible in their workplace.
Radiation and Environmental Biophysics
Radiation dose estimations performed by automated counting of micronuclei (MN) have been studied ... more Radiation dose estimations performed by automated counting of micronuclei (MN) have been studied for their utility for triage following large-scale radiological incidents; although speed is essential, it also is essential to estimate radiation doses as accurately as possible for long-term epidemiological follow-up. Our goal in this study was to evaluate and improve the performance of automated MN counting for biodosimetry using the cytokinesis-block micronucleus (CBMN) assay. We measured false detection rates and used them to improve the accuracy of dosimetry. The average false-positive rate for binucleated cells was 1.14%; average false-positive and -negative MN rates were 1.03% and 3.50%, respectively. Detection errors seemed to be correlated with radiation dose. Correction of errors by visual inspection of images used for automated counting, called the semi-automated and manual scoring method, increased accuracy of dose estimation. Our findings suggest that dose assessment of the...
Nuclear Engineering and Technology
Journal of Radiation Research, 2019
The dicentric chromosome assay (DCA) is a well-established biodosimetry test to estimate exposure... more The dicentric chromosome assay (DCA) is a well-established biodosimetry test to estimate exposure to ionizing radiation. The Korea Institute of Radiological and Medical Sciences (KIRAMS) established a DCA protocol as a medical response to radiation emergencies in South Korea. To maintain its accuracy and performance, intercomparison exercises with Health Canada (HC) have been conducted; herein, we aimed to validate our capacity of DCA analysis based on those results. Blood samples irradiated at HC were shipped to KIRAMS to assess the irradiation dose to blinded samples using conventional DCA full scoring and triage-based techniques (conventional DCA scoring in triage mode and DCA QuickScan method). Actual doses fell within the 95% confidence intervals of dose estimates for 70–100% of the blinded samples in 2015–2018. All methods discriminated binary dose categories, reflecting clinical significance. This DCA can be used as a reliable radiation biodosimetry tool in preparation for ra...
Journal of radiation research, Jan 28, 2015
Two cases of hematological malignancies were reported in an industrial radiography company over a... more Two cases of hematological malignancies were reported in an industrial radiography company over a year, which were reasonably suspected of being consequences of prolonged exposure to ionizing radiation because of the higher incidence than expected in the general population. We analyzed chromosomal aberrations in the peripheral blood lymphocytes from the other workers who had been working under similar circumstances as the patients in the company. Among the subjects tested, 10 workers who belonged to the highest band were followed up periodically for 1.5 years since the first analysis. The aim of this study was to clarify pertinence of translocation analysis to an industrial set-up where chronic exposure was commonly expected. To be a useful tool for a retrospective biodosimetry, the aberrations need to be persistent for a decade or longer. Therefore we calculated the decline rates and half-lives of frequency for both a reciprocal translocation and a dicentric chromosome and compared...
... controls is that the operating point is oscillating around the MPP, even during sunny day whe... more ... controls is that the operating point is oscillating around the MPP, even during sunny day when irradiance and temperature are slowly varying ... Sang-Yong Kim, Sangsoo Park, Seong-Jae Jang, Gyeong-Hun Kim, Hyo-Ryong Seo, Minwon Park, Member, IEEE and In-Keun Yu ...
Journal of Biological Chemistry, 2008
Nuclear Engineering and Technology
Mutation research, 2021
Most blood components for transfusions are irradiated ex vivo to prevent transfusion-associated g... more Most blood components for transfusions are irradiated ex vivo to prevent transfusion-associated graft-versus-host disease (TA-GvHD); this irradiation can potentially affect the cytogenetic dose assessment of patients showing acute radiation syndrome (ARS) with bone marrow suppression or acute anaemia. Whole blood samples from five donors were irradiated with 0, 10 or 25 Gy γ-rays. The mitotic activity of each cultured blood sample was measured by calculating the mitotic index. A dicentric chromosome assay was used to evaluate the chromosomal aberrations and absorbed dose of blood lymphocytes. Mitogenic activity and scorable metaphase spreads were significantly decreased in the blood samples irradiated with 10 and 25 Gy (p < 0.001). Moreover, a significant increase in the mean scores of all types of chromosomal aberrations in the 10 Gy γ-irradiated samples was observed, with the estimated dose being 11.3 Gy (95% CI: 10.67-11.95 Gy); however, we were unable to estimate the exposure...
Mutation Research/Genetic Toxicology and Environmental Mutagenesis
International Journal of Radiation Biology
Purpose: In case of a mass-casualty radiological event, there would be a need for networking to o... more Purpose: In case of a mass-casualty radiological event, there would be a need for networking to overcome surge limitations and to quickly obtain homogeneous results (reported aberration frequencies or estimated doses) among biodosimetry laboratories. These results must be consistent within such network. Inter-laboratory comparisons (ILCs) are widely accepted to achieve this homogeneity. At the European level, a great effort has been made to harmonize biological dosimetry laboratories, notably during the MULTIBIODOSE and RENEB projects. In order to continue the harmonization efforts, the RENEB consortium launched this intercomparison which is larger than the RENEB network, as it involves 38 laboratories from 21 countries. In this ILC all steps of the process were monitored, from blood shipment to dose estimation. This exercise also aimed to evaluate the statistical tools used to compare laboratory performance. Materials and methods: Blood samples were irradiated at three different doses, 1.8, 0.4 and 0 Gy (samples A, C and B) with 4-MV X-rays at 0.5 Gy min À1 , and sent to the participant laboratories. Each laboratory was requested to blindly analyze 500 cells per sample and to report the observed frequency of dicentric chromosomes per metaphase and the corresponding estimated dose. Results: This ILC demonstrates that blood samples can be successfully distributed among laboratories worldwide to perform biological dosimetry in case of a mass casualty event. Having achieved a substantial harmonization in multiple areas among the RENEB laboratories issues were identified with the available statistical tools, which are not capable to advantageously exploit the richness of results of a large ILCs. Even though Zand U-tests are accepted methods for biodosimetry ILCs, setting the number of analyzed metaphases to 500 and establishing a tests' common threshold for all studied doses is inappropriate for evaluating laboratory performance. Another problem highlighted by this ILC is the issue of the dose-effect curve diversity. It clearly appears that, despite the initial advantage of including the scoring specificities of each laboratory, the lack of defined criteria for assessing the robustness of each laboratory's curve is a disadvantage for the 'one curve per laboratory' model.
Mutation Research/Genetic Toxicology and Environmental Mutagenesis
Nuclear Engineering and Technology
Disaster Medicine and Public Health Preparedness
This training session is organized by the Korea Institute of Radiological and Medical Sciences (K... more This training session is organized by the Korea Institute of Radiological and Medical Sciences (KIRAMS), which conducts practical training in medical treatments during nuclear disasters based on the international standards for radiation protection. The practical training began with the assumption that a large-scale earthquake had caused an on-site emergency at the Kori Nuclear Power Plant (NPP); the aim of this training was to enhance control of the command system, information sharing, confirmation of triage, and patient distribution during an emergency situation. In this training, our group (the Japanese team) participated in REM as a radiation emergency medical assistance team including doctors, nurses, radiologic technologists, and logistics personnel, and cooperated with Korea's radiation emergency medical assistance team. In this study, we briefly introduce the contents of REM 2017 and discuss how we can make use of it in future education on nuclear disaster response.
Journal of Radiological Protection
Industrial radiographers are exposed to relatively higher doses of radiation than other radiation... more Industrial radiographers are exposed to relatively higher doses of radiation than other radiation-exposed workers in South Korea. The objective of our study was to investigate the impact of specific occupational conditions on chromosome aberration frequency and evaluate dosimeter-wearing compliance of industrial radiographers in Korea. We studied individual and occupational characteristics of 120 industrial radiographers working in South Korea and evaluated the frequency of dicentrics and translocations in chromosomes to estimate radiation exposure. The association between working conditions and chromosome aberration frequencies was assessed by Poisson regression analysis after adjusting for confounding factors. Legal personal dosimeter-wearing compliance among workers was investigated by correlation analysis between recorded dose and chromosome aberration frequency. Daily average number of radiographic films used in the last 6 months was associated with dicentrics frequency. Workers performing site radiography showed significantly higher translocation frequency than those working predominantly in shielded enclosures. Correlation between chromosome aberration frequency and recorded dose was higher in workers in radiography occupation since 2012 (new workers) than other veteran workers. Our study found that site radiography could affect actual radiation exposure to workers. Controlling these working conditions and making an effort to improve personal dosimeterwearing compliance for veteran workers as well as new workers may be necessary to reduce radiation exposure as much as possible in their workplace.