1.Presence and diversity of free-living amoebae and their potential application as water quality indicators
Areum CHOI ; Ji Won SEONG ; Jeong Hyun KIM ; Jun Young LEE ; Hyun Jae CHO ; Shin Ae KANG ; Mi Kyung PARK ; Mi Jin JEONG ; Seo Yeong CHOI ; Yu Jin JEONG ; Hak Sun YU
Parasites, Hosts and Diseases 2024;62(2):180-192
Free-living amoebae (FLA) are found in diverse environments, such as soils, rivers, and seas. Hence, they can be used as bioindicators to assess the water quality based solely on their presence. In this study, we determined the presence of FLA in river water by filtering water samples collected from various sites and culturing the resulting filtrates. FLA were detected in all the water samples with varying quality grades (Grades Ι-V). The significant increase in the size of the amoebae population with the deterioration in the water quality. Monoxenic cultures of the amoebae were performed, and genomic DNAs were isolated, among which 18S rDNAs were sequenced to identify the amoeba species. Of the 12 species identified, 10 belonged to the Acanthamoeba genus; of the remaining 2 species, one was identified as Vannella croatica and the other as a species of Vermamoeba. Acanthamoeba was detected in samples with Grades Ι to VI quality, whereas the Vermamoeba species was present only in Grade Ι water. V. croatica was found exclusively in water with Grade ΙΙ quality. Following morphological observations, genomic DNA was sequenced using 16S rDNA to determine whether the species of Acanthamoeba harbored endosymbionts. Most of the isolated Acanthamoeba contained endosymbionts, among which 4 species of endogenous bacteria were identified and examined using transmission electron microscopy. This study provides evidence that the distribution of amoebae other than Acanthamoeba may be associated with water quality. However, further confirmation will be required based on accurate water quality ratings and assessments using a more diverse range of FLA.
2.Promising Therapeutic Effectsof Embryonic Stem Cells-Origin Mesenchymal Stem Cells in Experimental Pulmonary Fibrosis Models: Immunomodulatory and Anti-Apoptotic Mechanisms
Hanna LEE ; Ok-Yi JEONG ; Hee Jin PARK ; Sung-Lim LEE ; Eun-yeong BOK ; Mingyo KIM ; Young Sun SUH ; Yun-Hong CHEON ; Hyun-Ok KIM ; Suhee KIM ; Sung Hak CHUN ; Jung Min PARK ; Young Jin LEE ; Sang-Il LEE
Immune Network 2023;23(6):e45-
Interstitial lung disease (ILD) involves persistent inflammation and fibrosis, leading to respiratory failure and even death. Adult tissue-derived mesenchymal stem cells (MSCs) show potential in ILD therapeutics but obtaining an adequate quantity of cells for drug application is difficult. Daewoong Pharmaceutical’s MSCs (DW-MSCs) derived from embryonic stem cells sustain a high proliferative capacity following long-term culture and expansion. The aim of this study was to investigate the therapeutic potential of DW-MSCs in experimental mouse models of ILD. DW-MSCs were expanded up to 12 passages for in vivo application in bleomycin-induced pulmonary fibrosis and collagen-induced connective tissue diseaseILD mouse models. We assessed lung inflammation and fibrosis, lung tissue immune cells, fibrosis-related gene/protein expression, apoptosis and mitochondrial function of alveolar epithelial cells, and mitochondrial transfer ability. Intravenous administration of DWMSCs consistently improved lung fibrosis and reduced inflammatory and fibrotic markers expression in both models across various disease stages. The therapeutic effect of DW-MSCs was comparable to that following daily oral administration of nintedanib or pirfenidone.Mechanistically, DW-MSCs exhibited immunomodulatory effects by reducing the number of B cells during the early phase and increasing the ratio of Tregs to Th17 cells during the late phase of bleomycin-induced pulmonary fibrosis. Furthermore, DW-MSCs exhibited antiapoptotic effects, increased cell viability, and improved mitochondrial respiration in alveolar epithelial cells by transferring their mitochondria to alveolar epithelial cells. Our findings indicate the strong potential of DW-MSCs in the treatment of ILD owing to their high efficacy and immunomodulatory and anti-apoptotic effects.
3.Adjuvant Imatinib Treatment for 5 Years versus 3 Years in Patients with Ruptured Localized Gastrointestinal Stromal Tumor: A Retrospective Analysis
Sora KANG ; Min-Hee RYU ; Yeong Hak BANG ; Hyung-Don KIM ; Hyung Eun LEE ; Yoon-Koo KANG
Cancer Research and Treatment 2022;54(4):1167-1174
Purpose:
Three years of adjuvant imatinib is the standard treatment for resected gastrointestinal stromal tumors (GISTs) with rupture, but the recurrence rate is prominently high. We aimed to investigate the efficacy and safety of 5-year adjuvant imatinib compared with 3-year treatment in patients with a ruptured GIST following surgical resection.
Materials and Methods:
A total of 51 patients were included in the analysis. The assessment of GIST rupture was based on Nishida’s classification. Twenty patients who were diagnosed before November 2013 were treated with 5 years of imatinib, and 31 patients who were diagnosed after November 2013 were treated with 3 years of imatinib. We retrospectively compared the clinical outcomes of the two groups.
Results:
Baseline characteristics and the incidence of the adverse events were generally comparable between the two groups. During a median follow-up duration of 43.8 months and 104.2 months in the 3- and 5-year group, 8 and 9 patients had a disease recurrence, respectively. The 5-year group showed better recurrence-free survival (RFS) than the 3-year group. In multivariate analysis, low mitotic index was a significant independent favorable prognostic factor for RFS, while 5-year imatinib treatment was marginally associated with a favorable RFS.
Conclusion
Five years of adjuvant imatinib treatment in patients with ruptured GIST was associated with favorable survival outcomes with manageable toxicity profiles. Our findings warrant validation and confirmation in future studies.
4.Effects of the Combination of Evogliptin and Leucine on Insulin Resistance and Hepatic Steatosis in High-Fat Diet-Fed Mice
Chang Yell SHIN ; Hak Yeong LEE ; Gil Hyung KIM ; Sun Young PARK ; Won Seok CHOI ; Uy Dong SOHN
Biomolecules & Therapeutics 2021;29(4):419-426
In this study, we aimed to investigate the effects of 8 weeks of treatment with a combination of evogliptin and leucine, a branchedchain amino acid, in mice with high-fat diet (HFD)-induced diabetes. Treatment with evogliptin alone or in combination with leucine reduced the body weight of the mice, compared to the case for those from the HFD control group. Long-term treatment with evogliptin alone or in combination with leucine resulted in a significant reduction in glucose intolerance; however, leucine alone did not affect postprandial glucose control, compared to the case for the mice from the HFD control group. Furthermore, the combination of evogliptin and leucine prevented HFD-induced insulin resistance, which was associated with improved homeostasis model assessment for insulin resistance, accompanied by markedly reduced liver fat deposition, hepatic triglyceride content, and plasma alanine aminotransferase levels. The combination of evogliptin and leucine increased the gene expression levels of hepatic peroxisome proliferator-activated receptor alpha, whereas those of the sterol regulatory element-binding protein 1 and stearoyl-CoA desaturase 1 were not altered, compared to the case in the HFD-fed mice (p<0.05). Thus, our results suggest that the combination of evogliptin and leucine may be beneficial for treating patients with type 2 diabetes and hepatic steatosis; however, further studies are needed to delineate the molecular mechanisms underlying the action of this combination.
5.Factors affecting incorrect interpretation of abdominal computed tomography in non-traumatic patients by novice emergency physicians
Seong Geun LEE ; Hanjin CHO ; Joo Yeong KIM ; Juhyun SONG ; Jong-Hak PARK
Clinical and Experimental Emergency Medicine 2021;8(3):207-215
Objective:
Accurate interpretation of computed tomography (CT) scans is critical for patient care in the emergency department. We aimed to identify factors associated with an incorrect interpretation of abdominal CT by novice emergency residents and to analyze the characteristics of incorrectly interpreted scans.
Methods:
This retrospective analysis of a prospective observational cohort was conducted at three urban emergency departments. Discrepancies between the interpretations by postgraduate year-1 (PGY-1) emergency residents and the final radiologists’ reports were assessed by independent adjudicators. Potential factors associated with incorrect interpretation included patient age, sex, time of interpretation, and organ category. Adjusted odds ratios (aORs) for incorrect interpretation were calculated using multivariable logistic regression analysis.
Results:
Among 1,628 eligible cases, 270 (16.6%) were incorrect. The urinary system was the most correctly interpreted organ system (95.8%, 365/381), while the biliary tract was the most incorrectly interpreted (28.4%, 48/169). Normal CT images showed high false-positive rates of incorrect interpretation (28.2%, 96/340). Organ category was found to be a major determinant of incorrect interpretation. Using the urinary system as a reference, the aOR for incorrect interpretation of biliary tract disease was 9.20 (95% confidence interval, 5.0–16.90) and the aOR for incorrectly interpreting normal CT images was 8.47 (95% confidence interval, 4.85–14.78).
Conclusion
Biliary tract disease is a major factor associated with incorrect preliminary interpretations of abdominal CT scans by PGY-1 emergency residents. PGY-1 residents also showed high false-positive interpretation rates for normal CT images. Emergency residents’ training should focus on these two areas to improve abdominal CT interpretation accuracy.
6.Effects of the Combination of Evogliptin and Leucine on Insulin Resistance and Hepatic Steatosis in High-Fat Diet-Fed Mice
Chang Yell SHIN ; Hak Yeong LEE ; Gil Hyung KIM ; Sun Young PARK ; Won Seok CHOI ; Uy Dong SOHN
Biomolecules & Therapeutics 2021;29(4):419-426
In this study, we aimed to investigate the effects of 8 weeks of treatment with a combination of evogliptin and leucine, a branchedchain amino acid, in mice with high-fat diet (HFD)-induced diabetes. Treatment with evogliptin alone or in combination with leucine reduced the body weight of the mice, compared to the case for those from the HFD control group. Long-term treatment with evogliptin alone or in combination with leucine resulted in a significant reduction in glucose intolerance; however, leucine alone did not affect postprandial glucose control, compared to the case for the mice from the HFD control group. Furthermore, the combination of evogliptin and leucine prevented HFD-induced insulin resistance, which was associated with improved homeostasis model assessment for insulin resistance, accompanied by markedly reduced liver fat deposition, hepatic triglyceride content, and plasma alanine aminotransferase levels. The combination of evogliptin and leucine increased the gene expression levels of hepatic peroxisome proliferator-activated receptor alpha, whereas those of the sterol regulatory element-binding protein 1 and stearoyl-CoA desaturase 1 were not altered, compared to the case in the HFD-fed mice (p<0.05). Thus, our results suggest that the combination of evogliptin and leucine may be beneficial for treating patients with type 2 diabetes and hepatic steatosis; however, further studies are needed to delineate the molecular mechanisms underlying the action of this combination.
7.Factors affecting incorrect interpretation of abdominal computed tomography in non-traumatic patients by novice emergency physicians
Seong Geun LEE ; Hanjin CHO ; Joo Yeong KIM ; Juhyun SONG ; Jong-Hak PARK
Clinical and Experimental Emergency Medicine 2021;8(3):207-215
Objective:
Accurate interpretation of computed tomography (CT) scans is critical for patient care in the emergency department. We aimed to identify factors associated with an incorrect interpretation of abdominal CT by novice emergency residents and to analyze the characteristics of incorrectly interpreted scans.
Methods:
This retrospective analysis of a prospective observational cohort was conducted at three urban emergency departments. Discrepancies between the interpretations by postgraduate year-1 (PGY-1) emergency residents and the final radiologists’ reports were assessed by independent adjudicators. Potential factors associated with incorrect interpretation included patient age, sex, time of interpretation, and organ category. Adjusted odds ratios (aORs) for incorrect interpretation were calculated using multivariable logistic regression analysis.
Results:
Among 1,628 eligible cases, 270 (16.6%) were incorrect. The urinary system was the most correctly interpreted organ system (95.8%, 365/381), while the biliary tract was the most incorrectly interpreted (28.4%, 48/169). Normal CT images showed high false-positive rates of incorrect interpretation (28.2%, 96/340). Organ category was found to be a major determinant of incorrect interpretation. Using the urinary system as a reference, the aOR for incorrect interpretation of biliary tract disease was 9.20 (95% confidence interval, 5.0–16.90) and the aOR for incorrectly interpreting normal CT images was 8.47 (95% confidence interval, 4.85–14.78).
Conclusion
Biliary tract disease is a major factor associated with incorrect preliminary interpretations of abdominal CT scans by PGY-1 emergency residents. PGY-1 residents also showed high false-positive interpretation rates for normal CT images. Emergency residents’ training should focus on these two areas to improve abdominal CT interpretation accuracy.
8.The hepato-protective effect of eupatilin on an alcoholic liver disease model of rats
Hak Yeong LEE ; Yoonjin NAM ; Won Seok CHOI ; Tae Wook KIM ; Jaehwi LEE ; Uy Dong SOHN
The Korean Journal of Physiology and Pharmacology 2020;24(5):385-394
Eupatilin is known to possess anti-apoptotic, anti-oxidative, and antiinflammatoryproperties. We report here that eupatilin has a protective effect onthe ethanol-induced injury in rats. Sprague–Dawley rats were divided into 6 groups:control, vehicle, silymarin, eupatilin 10 mg/kg, eupatilin 30 mg/kg, and eupatilin 100mg/kg. Plasma levels of aspartate aminotransferase (AST) and alanine aminotransferase(ALT) were analyzed to determine the extent of liver damage. Total cholesterol(TC) and triglycerides (TG) were analyzed to determine the level of liver steatosis.Malondialdehyde level, superoxide dismutase (SOD) activity, and glutathione (GSH)level were analyzed to determine the extent of oxidative stress. Tumor necrosis factor(TNF)- and interleukin (IL)-1 were quantified to verify the degree of inflammation.Based on our findings, chronic alcohol treatment significantly changed the serumindexes and liver indicators of the model rats, which were significantly improved byeupatilin treatment. Rats in the eupatilin-treatment group showed reduced levelsof AST, ALT, TG, TC, TNF-, and IL-1, increased SOD activity and GSH levels, and improvedoverall physiology compared to the alcoholic liver disease model rats. H&Estaining also verified the eupatilin-mediated improvement in liver injury. In conclusion,eupatilin inhibits alcohol-induced liver injury via its antioxidant and anti-inflammatoryeffects.
9.A survey on the perception of emergency medical services (EMS) providers and medical directors toward EMS provider’s field skill proficiency
Daesung LIM ; Seong Chun KIM ; Song Yi PARK ; Ji Ho RHU ; Byung Kwan BAE ; Sun Hyu KIM ; Byung Ho CHOI ; Tae Won YANG ; Jeong Eun KIM ; Ji Hoon KANG ; Min Hui KIM ; I Min KIM ; Yeong Hak JO ; Bong Kyu JEONG ; Jae Ki PARK ; Jun Jae CHA
Journal of the Korean Society of Emergency Medicine 2020;31(4):401-419
Objective:
This study aimed to investigate the perception of emergency medical service (EMS) providers and medical directors toward the field skill proficiency of EMS providers. We further examined differences in perception according to the certification and hospital career of individuals.
Methods:
This survey was conducted enrolling all active EMS providers in Busan, Ulsan, and Gyeongnam, as well as emergency physicians who participated in direct medical direction. Pre-developed questionnaires were sent as text messages to individual EMS providers and emergency physicians using an internet-based survey tool (Google Forms).Questionnaires were composed of 25 items in 7 categories: “airway management”, “ventilatory support”, “circulatory support”, “field assessment and management of trauma patients”, “field assessment and management of patients with chest pain”, “field assessment and management of patients with neurologic symptoms”, and “other items”. The response was based on a five-point Likert scale, where 0 score indicated no experience at all.
Results:
The questionnaire was distributed to 1,781 EMS providers and 52 medical directors; of these, 1,314 (73.7%) EMS providers and 34 (65.3%) medical directors completed the survey. EMS providers rated themselves as above average (3 points) for most of the questions. However, the majority responded that they had no experience or low proficiency in endotracheal intubation and prehospital delivery (median 2; interquartile range [IQR], 0-3). Conversely, medical directors assessed the EMS provider’s proficiency as above average in use of I-gel, recognition of hypoglycemia, field management of trauma patients, use of oropharyngeal and nasopharyngeal airway, use of laryngeal mask airway, and optimal oxygen supply (median, 4; IQR, 3-4), but responded with low scores for most other questions. Based on the EMS provider certification, nurses scored themselves more proficient than level-1 emergency medical technicians (EMTs) for intravenous access (P<0.001), whereas level-1 EMTs recognized themselves more proficient than nurses for endotracheal intubation (P<0.001), use of Magill forceps (P=0.004), and pediatric cardiopulmonary resuscitation (P<0.001).
Conclusion
This study recognized the discrepancies in the perception of EMS provider’s field skill proficiency, as perceived by EMS providers and medical directors, and between level-1 EMTs and nurses. We propose that regional EMS authorities need to make persistent efforts to narrow these perception gaps through effective educational programs for EMS providers and medical directors.
10.2019 Tabletop Exercise for Laboratory Diagnosis and Analyses of Unknown Disease Outbreaks by the Korea Centers for Disease Control and Prevention
Il-Hwan KIM ; Jun Hyeong JANG ; Su-Kyoung JO ; Jin Sun NO ; Seung-Hee SEO ; Jun-Young KIM ; Sang-Oun JUNG ; Jeong-Min KIM ; Sang-Eun LEE ; Hye-Kyung PARK ; Eun-Jin KIM ; Jun Ho JEON ; Myung-Min CHOI ; Bo yeong RYU ; Yoon Suk JANG ; Hwa mi KIM ; Jin LEE ; Seung-Hwan SHIN ; Hee Kyoung KIM ; Eun-Kyoung KIM ; Ye Eun PARK ; Cheon-Kwon YOO ; Sang-Won LEE ; Myung-Guk HAN ; Gi-Eun RHIE ; Byung Hak KANG
Osong Public Health and Research Perspectives 2020;11(5):280-285
Objectives:
The Korea Centers for Disease Control and Prevention has published “A Guideline for Unknown Disease Outbreaks (UDO).” The aim of this report was to introduce tabletop exercises (TTX) to prepare for UDO in the future.
Methods:
The UDO Laboratory Analyses Task Force in Korea Centers for Disease Control and Prevention in April 2018, assigned unknown diseases into 5 syndromes, designed an algorithm for diagnosis, and made a panel list for diagnosis by exclusion. Using the guidelines and laboratory analyses for UDO, TTX were introduced.
Results:
Since September 9th , 2018, the UDO Laboratory Analyses Task Force has been preparing TTX based on a scenario of an outbreak caused by a novel coronavirus. In December 2019, through TTX, individual missions, epidemiological investigations, sample treatments, diagnosis by exclusions, and next generation sequencing analysis were discussed, and a novel coronavirus was identified as the causal pathogen.
Conclusion
Guideline and laboratory analyses for UDO successfully applied in TTX. Conclusions drawn from TTX could be applied effectively in the analyses for the initial response to COVID-19, an ongoing epidemic of 2019 - 2020. Therefore, TTX should continuously be conducted for the response and preparation against UDO.

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