1.Existing test data for the Act on Registration & Evaluation, etc. of Chemical Substances.
Bong In CHOI ; Byung Taek RYU ; Suk Hyun NA ; Seon Yong CHUNG
Environmental Health and Toxicology 2015;30(1):e2015017-
OBJECTIVES: In this study, the possibility of using existing test data provided in Korea and elsewhere for the registration of chemical substances was examined. Data on 510 chemical substances that are among the first subject to registration under the “Act on the Registration and Evaluation, etc. of Chemical Substances (K-REACH)” were analyzed. METHODS: The possibility of using existing data from 16 reference databases was examined for 510 chemical substances notified in July 2015 as being subject to registration. RESULTS: Test data with the reliability required for the registration of chemical substances under the K-REACH constituted 48.4% of the required physicochemical characteristics, 6.5% of the required health hazards, and 9.4% of the required environmental hazards. CONCLUSIONS: Some existing test data were not within the scope of this research, including data used for registration in the European Union (EU). Thus, considering that 350 of these 510 species are registered in EU Registration, Evaluation, Authorisation & Restriction of Chemicals, more test data may exist that can be utilized in addition to the data identified in this study. Furthermore, the K-REACH states that non-testing data (test results predicted through Read Across, Quantitative Structure- Activity Relationships) and the weight of evidence (test results predicted based on test data with low reliability) can also be utilized for registration data. Therefore, if methods for using such data were actively reviewed, it would be possible to reduce the cost of securing test data required for the registration of chemical substances.
European Union
;
Korea
2.Existing test data for the Act on Registration & Evaluation, etc. of Chemical Substances.
Bong In CHOI ; Byung Taek RYU ; Suk Hyun NA ; Seon Yong CHUNG
Environmental Health and Toxicology 2015;30(1):e2015017-
OBJECTIVES: In this study, the possibility of using existing test data provided in Korea and elsewhere for the registration of chemical substances was examined. Data on 510 chemical substances that are among the first subject to registration under the “Act on the Registration and Evaluation, etc. of Chemical Substances (K-REACH)” were analyzed. METHODS: The possibility of using existing data from 16 reference databases was examined for 510 chemical substances notified in July 2015 as being subject to registration. RESULTS: Test data with the reliability required for the registration of chemical substances under the K-REACH constituted 48.4% of the required physicochemical characteristics, 6.5% of the required health hazards, and 9.4% of the required environmental hazards. CONCLUSIONS: Some existing test data were not within the scope of this research, including data used for registration in the European Union (EU). Thus, considering that 350 of these 510 species are registered in EU Registration, Evaluation, Authorisation & Restriction of Chemicals, more test data may exist that can be utilized in addition to the data identified in this study. Furthermore, the K-REACH states that non-testing data (test results predicted through Read Across, Quantitative Structure- Activity Relationships) and the weight of evidence (test results predicted based on test data with low reliability) can also be utilized for registration data. Therefore, if methods for using such data were actively reviewed, it would be possible to reduce the cost of securing test data required for the registration of chemical substances.
European Union
;
Korea
3.Pneumothorax after Interventional Muscle and Soft Tissue Stimulation Therapy : A case report.
Young Taek KIM ; Byung Soon PARK ; Ji Keun RYU ; Byung Jun LEE
Anesthesia and Pain Medicine 2007;2(3):117-121
Pneumothorax is the presence of gas in the pleural space. Traumatic pneumothorax results from penetrating or nonpenetrating chest injuries and iatrogenic pneumothorax occurs as a consequence of a diagnostic or therapeutic maneuver. When interventional muscle and soft tissue stimulation (IMNS) therapy is performed, iatrogenic pneumothorax is not common, but once it has occurred, it gives suffering and pain to both the patient and physician. We experienced three cases of iatrogenic pneumothorax after IMNS therapy. Commonly, the patients with peumothorax are treated with a tube thoracostomy on admission, but these patients can be simply treated with simple observation, oxygen inhalation and simple aspiration without admission and the results are satisfactory. Although iatogenic pneumothorax after IMNS therapy appears to be an rare, IMNS procedure still must be done with care.
Humans
;
Inhalation
;
Oxygen
;
Pneumothorax*
;
Thoracic Injuries
;
Thoracostomy
4.Effect of the K+ Channel Modulations on Glutamate and K+ Concentrations in Rabbit Hippocampus during Transient Global Ischemia.
Kyu Taek CHOI ; Myung Won CHO ; Byung Te SUH ; Jeong Rak LEE ; Hyung Seop PARK ; Pan Dong RYU
Korean Journal of Anesthesiology 1999;36(3):510-517
BACKGROUND: Cerebral ischemia causes an increase in extracellular potassium ([K+]e) through activation of the KATP channel. This increase in [K+]e could result in neuronal depolarization and a reversal of the glutamate uptake system in glia. This may further contribute to the excessive concentrations of glutamate and asparate in the extracellular space during ischemia. If the early rise in [K+]e during ischemia could be attenuated, less excitotoxic neuronal damage may be the result. However, activation of KATP channels has been shown to attenuate the anoxia induced depolarization in the hippocampus and may reduce the release of excitatory neurotransmitters during cerebral ischemia. In this study, we address the question of whether KATP channel modulation affects [K+]e and whether it is related with extracellular glutamate concentrations. METHODS: After approval by the Animal Care and Use Committee, 18 New Zealand white rabbits were anesthetized with halothane and mechanically ventilated to maintain normocarbia. Microdialysis catheters were inserted into the left dorsal hippocampus and perfused with artificial cerebrospinal fluid at 2 ml/min. K+ sensitive microelectrodes were inserted into the contralateral hippocampus. A pneumatic tourniquet was placed loosely around the neck. Animals were randomized to receive glibenclamide (n=5, KATP blocker, 3.7 mg/kg) or cromakalim (n=5, KATP opener, 0.5 mg/kg). The control group (n=6) had neither drug. Ten-minute period of global cerebral ischemia was produced by inflation of the tourniquet combined with induced hypotension. Hippocampal [K+]e was measured throughout the periischemic period and glutamate concentrations in dialysate were determined by high-performance liquid chromatography. Peak levels were compared by ANOVA. RESULTS: Glutamate concentration significantly increased during ischemia period for all groups (p<0.05). In glibenclamide treated animals, brain glutamate concentration increased markedly during early reperfusion (t=I+15) compared to other groups (p<0.05). There were no statistical differences on ischemia-induced increases in [K+]e among the three groups. CONCLUSIONS: Although it was not possible to demonstrate an effect of modulators of the ATP sensitive K+ channel on [K+]e, glibenclamide increased glutamate during reperfusion. This paradoxical increase in glutamate after administration of a K+ channel blocker suggests that the mechanism of glutamate release is not related to [K+]e change.
Adenosine Triphosphate
;
Animals
;
Anoxia
;
Brain
;
Brain Ischemia
;
Catheters
;
Cerebrospinal Fluid
;
Chromatography, Liquid
;
Cromakalim
;
Extracellular Space
;
Glutamic Acid*
;
Glyburide
;
Halothane
;
Hippocampus*
;
Hypotension
;
Inflation, Economic
;
Ischemia*
;
KATP Channels
;
Microdialysis
;
Microelectrodes
;
Neck
;
Neuroglia
;
Neurons
;
Neurotransmitter Agents
;
Potassium
;
Rabbits
;
Reperfusion
;
Tourniquets
5.Study on the biodegradation of alternatives (four species including C8H8F9KO3S) for perfluorooctane sulfonate.
Bong In CHOI ; Suk Hyun NA ; Yeong Don KWAK ; Byung Taek RYU ; Seon Yong CHUNG
Environmental Health and Toxicology 2015;30(Suppl):s2015008-
OBJECTIVES: The objective of this study was to evaluate the biodegradation potential of four perfluorooctane sulfonic acid (PFOS) alternatives that were developed at Changwon National University. While PFOS has been used widely in industrial and consumer products, it is known to be a persistent organic pollutant. Therefore, greener alternatives are highly desirable. METHODS: Biodegradation tests were run for 28 days using standard test protocols. The biochemical oxygen demand was measured daily throughout the experimental period, and the data were used to calculate the biodegradation rates. Microorganisms were isolated from the some of the tests that showed evidence of biodegradation. RESULTS: C8H8F9KO3S, which has the same number of carbons as the parent compound PFOS but a reduced number of fluorines, showed the highest biodegradation rate followed by C10H8F13KO3S. Chemical alternatives with lower number of carbons did not biodegrade readily in the experiments. CONCLUSIONS: Together, these results suggest that it may be advantageous to develop PFOS alternatives with 8 carbons, the same as PFOS, but a reduced number of fluorines; as such, chemicals are more susceptible to biodegradation than the parent compound.
Carbon
;
Green Chemistry Technology
;
Gyeongsangnam-do
;
Humans
;
Oxygen
;
Parents
6.Analysis of the utilization of existing test data for phase-in substance registration under the Act on the Registration and Evaluation, etc. of Chemical Substances.
Bong In CHOI ; Yeong Don KWAK ; Yu Mi JUNG ; Byung Taek RYU ; Chang Gyun KIM
Environmental Health and Toxicology 2015;30(Suppl):s2015004-
OBJECTIVES: Approximately 2000 phase-in substances are subject to registration according to the Act on the Registration and Evaluation, etc. of Chemical Substances (KREACH), and the expected testing cost is 2.06 trillion Korean won assuming all the test data required for registration are acquired. The extent to which these enormous test costs can be reduced depends on the availability of existing data that can be used to meet the requirements of the K-REACH we examined the current availability of test data that can be used for chemical substance registration. METHODS: We analyzed the possibility of utilizing the existing test data obtained from 16 reference databases for 369 of 518 kinds of phase-in substances subject to registration that were reported in last October 2014. RESULTS: The physical and chemical properties were available for 57.1% of substances, whereas data regarding human hazards and environmental hazards were available at considerably lower rates, 8.5% and 11.8%, respectively. CONCLUSIONS: Physical and chemical properties were available for a fairly high proportion, whereas human hazards and environmental hazards were reported for considerably fewer substances.
Chemical Safety
;
Hazardous Substances
;
Humans
;
Safety Management
7.Neural Substrates of Posttraumatic Stress Disorder: Functional Magnetic Resonance Imaging Study Using Negative Priming Task.
Byeong Taek LEE ; Jeong RYU ; Dong Hoon LEE ; Myeong Ho SOHN ; Nae Hee KANG ; Byung Joo HAM ; Nam Hee CHOI
Journal of the Korean Society of Biological Psychiatry 2008;15(2):110-117
OBJECTIVES: Posttraumatic stress disorder(PTSD) has been primarily associated with emotional problems. Recently, however, the impact of PTSD on cognitive processes has interested a growing number of researchers. The current study is aimed at investigating the cognitive aspects of PTSD at both behavioral and neurological levels. METHODS: We recruited individuals with PTSD who survived the Daegu subway explosion in 2003 as well as non-PTSD individuals as a control group. To evaluate the inhibitory processes and the neural mechanisms, we had these individuals perform the negative priming task simultaneously with functional MRI scanning. RESULTS: Behaviorally, the negative priming effect was intact in the control group but was not evident in the PTSD group. In the imaging results, only the PTSD group showed the negative priming effect (i.e., increased activation of the negative priming condition as opposed to the neutral condition) in the dorsolateral prefrontal cortex, anterior cingulate cortex, and inferior temporal gyrus. The PTSD group also showed increased activity for the positive priming condition as opposed to the neutral condition in the claustrum. These results confirm and extend the previous findings that the integrity of the ACC is compromised in the trauma survivors due to disrupted white matter tract. CONCLUSIONS: The current results suggest that deteriorated performance of the PTSD group may be due to the functional problem as well as the structural abnormalities.
Basal Ganglia
;
European Continental Ancestry Group
;
Explosions
;
Gyrus Cinguli
;
Humans
;
Magnetic Resonance Imaging
;
Magnetic Resonance Spectroscopy
;
Magnetics
;
Magnets
;
Prefrontal Cortex
;
Railroads
;
Stress Disorders, Post-Traumatic
;
Survivors
8.Comparative analysis on the effectiveness of transvaginal radiofrequency myolysis for conservative management of leiomyoma and adenomyosis.
Ji Hoon RYU ; Ki Hwan KIM ; Jun Suk PARK ; Yoon Seok YANG ; Kwan Young OH ; Jeong Hoon RHO ; Byung Kwan LEE ; Young Rae SONG ; In Taek HWANG
Korean Journal of Obstetrics and Gynecology 2008;51(1):48-59
OBJECTIVE: To compare the clinical effectiveness of transvaginal radiofrequency myolysis of the patients with leiomyomas and the patients with adenomyosis which have similar clinical symptoms. METHODS: From May 2005 to May 2006 at Eulji university hospital, 108 women who were diagnosed of leiomyoma and adenomyosis had undergone transvaginal radiofrequency myolysis. Before and after the procedure size, number of uterine myomas, location and the volume of the leiomyomas and adenomyosis were measured by ultrasound. And on every visit after the procedure improvement of the symptom was checked by questionnaire of the symptom and life quality. Using Wilcoxon signed ranked test, the statistical significance was proved and the P value lower than 0.05 was judged to be significant. RESULTS: 76 women with leiomyoma who had undergone transvaginal radiofrequency myolysis, were followed up 1 month, 3 months, 6 months and 9 months after the procedure. The average maximal diameter of the myoma was decreased by 14.6%, 23.3%, 30.6%, 33.6% respectively, and the average volume was decreased by 35.7%, 53.3%, 67.3%, 72.2% respectively. 32 women with adenomyosis who had undergone transvaginal radiofrequency myolysis were followed up, at the same period after the procedure. The average maximal diameter of the adenomyosis was decreased by 8.9%, 13.6%, 14.6%, 11.9% respectively, and the average volume was decreased by 22.6%, 30.0%, 32.3%, 28.4% respectively. Before and after the procedure the symptom score was 62.3, 52.2, 40.6, 32.6, 28.6 respectively, and the quality of life score was 68.9, 78.1, 82.9, 85.7, 87.3 respectively in the leiomyoma group. In the adenomyosis group, before and after the procedure the symptom score was 77.7, 37.6, 30.6, 54.4, 67.5 respectively, and the quality of life score was 48.1, 76.5, 85.5, 66.5, 55.1 respectively. CONCLUSION: Transvaginal radiofrequent myolysis had benefits in conserving the uterus, and was less invasive, and had great effect on the reducing the size of the leiomyoma and improving the symptoms, and also returning to normal life pattern was earlier. But in women with adenomyosis the symptoms were worsened after approximately 6 to 9 months after the procedure. Therefore additional research and follow-up is required and a strict criterion is needed.
Adenomyosis
;
Female
;
Follow-Up Studies
;
Humans
;
Leiomyoma
;
Myoma
;
Quality of Life
;
Surveys and Questionnaire
;
Uterus
9.Study on the biodegradation of perfluorooctanesulfonate (PFOS) and PFOS alternatives.
Bongin CHOI ; Suk Hyun NA ; Jun Hyo SON ; Dong Soo SHIN ; Byung Taek RYU ; Kyun Suk BYEON ; Seon yong CHUNG
Environmental Health and Toxicology 2016;31(1):e2016002-
OBJECTIVES: In this study, we investigated the biodegradation features of 4 perfluorooctanesulfonate (PFOS) alternatives developed at Changwon National University compared to those of PFOS. METHODS: Biodegradation testing was performed with microorganisms cultured in the good laboratory practice laboratory of the Korea Environment Corporation for 28 days following the Organization for Economic Cooperation and Development guidelines for the testing of chemicals (Test No. 301 C). RESULTS: While C₈F₁₇SO₃Na, PFOS sodium salt was not degraded after 28 days, the 4 alternatives were biodegraded at the rates of 20.9% for C₁₅F₉H₂₁S₂O₈Na₂, 8.4% for C₁₇F₉H ₂₅S₂O₈Na₂, 22.6% for C₂₃F₁₈H₂₈S₂O₈Na₂, and 23.6% for C₂₅F₁₇H₃₂O₁₃S₃Na₃. CONCLUSIONS: C₂₅F₁₇H₃₂S₃O₁₃Na₃, C₂₃F₁₈H₂₈S₂O₈Na₂, and C₁₅F₉H₂₁S₂O₈Na₂ were superior to PFOS in terms of biodegradation rates and surface tension, and thus they were considered highly applicable as PFOS alternatives. Environmental toxicity, human toxicity, and economic feasibility of these compounds should be investigated prior to their commercialization.
Gyeongsangnam-do
;
Humans
;
Korea
;
Organisation for Economic Co-Operation and Development
;
Sodium
;
Surface Tension
10.A Case of Pediatric Nephrolithiasis Associated with Topiramate Treatment.
Kyung Taek HONG ; Hye Won RYU ; Kihyun DOO ; Jae So CHO ; Anna CHO ; Byung Chan LIM ; Jong Hee CHAE ; Ki Joong KIM ; Yong Seung HWANG ; Hee HWANG
Journal of the Korean Child Neurology Society 2010;18(1):112-116
Topiramate is an antiepileptic drug widely used to treat various seizures, mood disorders and migraine based on its various pharmacological mechanisms. Even though nephrolithiasis is listed as one of its side effects, there have been no cases reporting nephrolithiasis caused by use of topiramate on Korean pediatric patients. Since the use of topiramate is increasing in many patients, the possibility of nephrolithiasis after the treatment needs to be considered. Here, we report our experience in correcting neprholithiasis by simply discontinuing topiramate without administering any additional treatments.
Anticonvulsants
;
Fructose
;
Humans
;
Migraine Disorders
;
Mood Disorders
;
Nephrolithiasis
;
Seizures