1.Reducing Microbial Contamination in Hematopoietic Stem Cell Products and Quality Improvement Strategy: Retrospective Analysis of 1996-2021 Data
You Keun KO ; Jong Kwon LEE ; Hye Kyung PARK ; Ae Kyung HAN ; Sun Kyoung MUN ; Hye Jeong PARK ; Hae Kyoung CHOUNG ; Se Mi KIM ; Kwang Mo CHOI ; Nam Yong LEE ; Duck CHO ; Dae Won KIM ; Eun-Suk KANG
Annals of Laboratory Medicine 2023;43(5):477-484
Background:
Sterility and safety assurance of hematopoietic stem cell (HSC) products is critical in transplantation. Microbial contamination can lead to product disposal and increases the risk of unsuccessful clinical outcomes. Therefore, it is important to implement and maintain good practice guidelines and regulations for the HSC collection and processing unit in each hospital. We aimed to share our experiences and suggest strategies to improve the quality assurance of HSC processing.
Methods:
We retrospectively analyzed microbial culture results of 11,743 HSC products processed over a 25-year period (January 1996 to May 2021). Because of reorganization of the HSC management system in 2008, the 25-year period was divided into periods 1 (January 1996 to December 2007) and 2 (January 2008 to May 2021). We reviewed all culture results of the HSC products and stored aliquot samples and collected culture results for peripheral blood and catheter samples.
Results:
Of the 11,743 products in total, 35 (0.3%) were contaminated by microorganisms, including 19 (0.5%) of 3,861 products during period 1 and 16 (0.2%) of 7,882 products during period 2. Penicillium was the most commonly identified microorganism (15.8%) during period 1 and coagulase-negative Staphylococcus was the most commonly identified (31.3%) during period 2. HSC product contamination occurred most often during HSC collection and processing.
Conclusions
The contamination rate decreased significantly during period 2, when the HSC management system was reorganized. Our results imply that handling HSC products by trained personnel and adopting established protocols, including quality assurance programs, aid in decreasing the contamination risk.
2.Effects of Token Economy Intervention on Hospitalized Patients With Schizophrenia
Sung-Jin KIM ; Young-Soo SEO ; Kyoung-Duck PARK ; Jung-Joon MOON ; Jae-Hoon JEONG ; Do-Un JUNG
Korean Journal of Schizophrenia Research 2023;26(1):18-23
Objectives:
The purpose of this study was to investigate the effect of token economy intervention on the clinical characteristics and global function of patients with schizophrenia.
Methods:
From June 1, 2022 to September 1, 2022, token economy intervention was conducted for hospitalized patients with schizophrenia in a mental hospital. Assessments were conducted before and after the intervention. Clinical Global Impression-Schizophrenia scale (CGI-SCH), Schizophrenia Quality of Life Scale (SQLS), Insight Scale for Psychosis (ISP), and Apathy Evaluation Scale (AES) were used to evaluate clinical characteristics. World Health Organization Disability Assessment Schedule (WHODAS) was used for global functional assessment.
Results:
A total of 51 patients were included in the study. Through token economy intervention, depressive (p=0.001), cognitive symptom domain scores (p<0.001) in CGI-SCH, and SQLS score were significantly decreased (p=0.044). In the WHODAS evaluated by the clinician, the scores of self-care (p=0.012), life activities (p=0.006), and participation in society (p=0.040) decreased significantly.
Conclusion
It was confirmed that token economy intervention had a positive effect on depressive symptoms, cognitive symptoms, quality of life, self-care function, daily living function, and social participation function in hospitalized patients with schizophrenia.
3.A simplified two-marker immunohistochemistry strategy for Lynch syndrome screening in endometrial cancer patients
Ala AIOB ; Yeo Rae KIM ; Kidong KIM ; Hyojin KIM ; Yong Beom KIM ; Duck Woo KIM ; Jae Hong NO ; Soo Hyun SEO ; Dong Hoon SUH ; Kyoung Un PARK
Obstetrics & Gynecology Science 2023;66(6):537-544
Objective:
To examine the efficacy of MSH6 and PMS2 immunohistochemistry (IHC) as a screening method for Lynch syndrome in endometrial cancer patients.
Methods:
Through multidisciplinary discussions, an institutional MSH6 and PMS2 IHC-initiated cascade test (MSH6, PMS2 IHC→microsatellite instability [MSI] assay→germline mismatch repair [MMR] gene sequencing) was developed to screen for Lynch syndrome in endometrial cancer patients. Testing was performed on a consecutive cohort of 218 newly diagnosed endometrial cancer patients who underwent surgery at a tertiary hospital in the Republic of Korea between August 2018 and December 2020. The number of MMR deficiencies (MSH6 or PMS2 loss in IHC) and results of subsequent tests (MSI assay and germline MMR gene sequencing) were examined.
Results:
MMR deficiency was detected in 52 of the 218 patients (24.0%). Among these 52 patients, 34 (65.0%) underwent MSI testing, of which 31 (91.0%) exhibited high MSI. Of the 31 patients with MSI-high status, 15 (48.0%) underwent germline MMR gene sequencing. Subsequently, Lynch syndrome was diagnosed in five patients (33.0%).
Conclusion
Lynch syndrome screening using MSH6 and PMS2 IHC-initiated cascade testing is a viable strategy in the management of endometrial cancer. A simplified strategy (MSH6 and PMS2 IHC→germline MMR gene sequencing) was proposed because most women with MMR deficiencies exhibited high MSI.
4.Plasma Circulating Tumor DNA in Patients with Primary Central Nervous System Lymphoma
Sang Eun YOON ; Yeon Jeong KIM ; Joon Ho SHIM ; Donghyun PARK ; Junhun CHO ; Young Hyeh KO ; Woong-Yang PARK ; Yeung-Chul MUN ; Kyoung Eun LEE ; Duck CHO ; Won Seog KIM ; Seok Jin KIM
Cancer Research and Treatment 2022;54(2):597-612
Purpose:
Analysis of circulating tumor DNA (ctDNA) in blood could allow noninvasive genetic analysis of primary tumors. Although there have been unmet needs for noninvasive methods in patients with primary central nervous system lymphoma (PCNSL), it is still not determined whether plasma ctDNA analysis could be useful for patients with PCNSL.
Materials and Methods:
Targeted deep sequencing of 54 genes was performed in cell-free DNA isolated from plasma samples collected pretreatment, during treatment, and at the end of treatment in 42 consecutively diagnosed PCNSL patients between January 2017 and December 2018.
Results:
Targeted sequencing of plasma cell-free DNA detected somatic mutations representing ctDNA in 11 cases (11/41, 27%). The detection of ctDNA was not related to the concentration of cell-free DNA or tumor volume. The mutation profiles of these 11 cases varied between patients. The most frequently mutated gene was PIM1 (4/11, 36.4%), whereas KMT2D, PIK3CA, and MYD88 were each observed in three patients (3/11, 27%). The mutations of 13 genes were concordantly found in primary tumor tissue and plasma ctDNA, giving a detection sensitivity of 45%. During the serial tracking of seven patients with complete response, the disappearance of ctDNA mutations was found in four patients, whereas three patients had detected ctDNA mutation at the end of treatment.
Conclusion
The plasma ctDNA mutation analysis still has limited value for surveillance and predicting treatment outcomes of PCNSL because the detection efficiency was lower than other systemic lymphomas. Thus, analytical platforms should be improved to overcome anatomical hurdles associated with PCNSL.
5.Comparison of oncologic outcomes between patients with Lynch syndrome and sporadic microsatellite instability-high colorectal cancer
Il Tae SON ; Duck-Woo KIM ; Min Hyun KIM ; Young-Kyoung SHIN ; Ja-Lok KU ; Heung-Kwon OH ; Sung-Bum KANG ; Seung-Yong J JEONG ; Kyu Joo PARK
Annals of Surgical Treatment and Research 2021;101(1):13-19
Purpose:
Long-term oncologic differences in outcome between groups of patients with Lynch syndrome (LS) colorectal cancer (CRC) and sporadic CRC with microsatellite instability-high (MSI-H) are the focus of investigation in the current study.
Methods:
Patients registered in the Korean Hereditary Tumor Registry and 2 tertiary referral hospitals treated for stage I– III CRC between 2005 and 2015 were retrospectively analyzed. Detection for both groups was performed using pedigree, microsatellite instability, and mismatch repair (MMR) gene testing. Multivariate analyses for overall survival (OS) and disease-free survival (DFS) were conducted.
Results:
Cases of LS (n = 77) and sporadic CRC with MSI-H (n = 96) were identified. LS CRC patients were younger in age and displayed tumor sidedness, typically involving left-sided colon and rectum, compared to patients with sporadic CRC with MSI-H. OS and DFS were lower for LS CRC relative to CRC with MSI-H (OS, 72.7% vs. 93.8%, P = 0.001; DFS, 71.4% vs. 88.5%, P = 0.001). In multivariate analyses, tumor sidedness, stage, and chemotherapy were independent factors for OS and DFS. LS CRC was a prognostic factor for poorer OS (hazard ratio, 2.740; 95% confidence interval, 1.003–7.487; P = 0.049), but not DFS.
Conclusion
Our findings indicate that LS CRC is associated with poorer outcomes compared to sporadic CRC with MSI-H, presenting distinct clinical features. In view of the current lack of knowledge on genetic and molecular mechanisms, appropriate management taking into consideration the difficulty of identification of CRC with hypermutable tumors harboring heterogeneity is essential.
6.Comparison of oncologic outcomes between patients with Lynch syndrome and sporadic microsatellite instability-high colorectal cancer
Il Tae SON ; Duck-Woo KIM ; Min Hyun KIM ; Young-Kyoung SHIN ; Ja-Lok KU ; Heung-Kwon OH ; Sung-Bum KANG ; Seung-Yong J JEONG ; Kyu Joo PARK
Annals of Surgical Treatment and Research 2021;101(1):13-19
Purpose:
Long-term oncologic differences in outcome between groups of patients with Lynch syndrome (LS) colorectal cancer (CRC) and sporadic CRC with microsatellite instability-high (MSI-H) are the focus of investigation in the current study.
Methods:
Patients registered in the Korean Hereditary Tumor Registry and 2 tertiary referral hospitals treated for stage I– III CRC between 2005 and 2015 were retrospectively analyzed. Detection for both groups was performed using pedigree, microsatellite instability, and mismatch repair (MMR) gene testing. Multivariate analyses for overall survival (OS) and disease-free survival (DFS) were conducted.
Results:
Cases of LS (n = 77) and sporadic CRC with MSI-H (n = 96) were identified. LS CRC patients were younger in age and displayed tumor sidedness, typically involving left-sided colon and rectum, compared to patients with sporadic CRC with MSI-H. OS and DFS were lower for LS CRC relative to CRC with MSI-H (OS, 72.7% vs. 93.8%, P = 0.001; DFS, 71.4% vs. 88.5%, P = 0.001). In multivariate analyses, tumor sidedness, stage, and chemotherapy were independent factors for OS and DFS. LS CRC was a prognostic factor for poorer OS (hazard ratio, 2.740; 95% confidence interval, 1.003–7.487; P = 0.049), but not DFS.
Conclusion
Our findings indicate that LS CRC is associated with poorer outcomes compared to sporadic CRC with MSI-H, presenting distinct clinical features. In view of the current lack of knowledge on genetic and molecular mechanisms, appropriate management taking into consideration the difficulty of identification of CRC with hypermutable tumors harboring heterogeneity is essential.
7.Similarity of the cut score in test sets with different item amounts using the modified Angoff, modified Ebel, and Hofstee standard-setting methods for the Korean Medical Licensing Examination
Janghee PARK ; Mi Kyoung YIM ; Na Jin KIM ; Duck Sun AHN ; Young-Min KIM
Journal of Educational Evaluation for Health Professions 2020;17(1):28-
Purpose:
The Korea Medical Licensing Exam (KMLE) typically contains a large number of items. The purpose of this study was to investigate whether there is a difference in the cut score between evaluating all items of the exam and evaluating only some items when conducting standard-setting.
Methods:
We divided the item sets that appeared on 3 recent KMLEs for the past 3 years into 4 subsets of each year of 25% each based on their item content categories, discrimination index, and difficulty index. The entire panel of 15 members assessed all the items (360 items, 100%) of the year 2017. In split-half set 1, each item set contained 184 (51%) items of year 2018 and each set from split-half set 2 contained 182 (51%) items of the year 2019 using the same method. We used the modified Angoff, modified Ebel, and Hofstee methods in the standard-setting process.
Results:
Less than a 1% cut score difference was observed when the same method was used to stratify item subsets containing 25%, 51%, or 100% of the entire set. When rating fewer items, higher rater reliability was observed.
Conclusion
When the entire item set was divided into equivalent subsets, assessing the exam using a portion of the item set (90 out of 360 items) yielded similar cut scores to those derived using the entire item set. There was a higher correlation between panelists’ individual assessments and the overall assessments.
8.Antibacterial effect of lidocaine in various clinical conditions
Hyeon Tae KIM ; Seung Woon LIM ; Kyoung Hoon YIM ; Sang Hi PARK ; Jung Hee CHOI ; Yoo Mee BAE ; Il Dong SHIN ; Young Duck SHIN
Anesthesia and Pain Medicine 2019;14(2):165-171
BACKGROUND: Infection, one of the complications associated with procedures, can cause fatal outcomes for patients. Although the local anesthetic agent we use is less susceptible to infection due to its antibacterial action, we performed this study to check the change in the antibacterial effect of lidocaine in various clinical conditions. METHODS: After exposing lidocaine to five contaminated environments, we checked on whether the bacteria could be cultured in blood agar plate (BAP) media. In each contaminated environment, lidocaine was exposed for 4 h (n = 9) and 8 h (n = 9), and the results were compared. Lidocaine was swabbed with chlorhexidine (group A), brought into contact with saliva (group B), skin (group C), an operating room floor and an outpatient room floor (group D), operating room air for 24 h (group A-a), and outpatient room air for 24 h (group A-b). After exposure, the culture was initiated. RESULTS: In 2 of 9 BAP media where lidocaine was exposed to saliva (group B) for 8 h, growth of a colony was observed. In gram staining, it was found to be Streptococcus viridans. No bacteria were found in any other groups. CONCLUSIONS: Though lidocaine has strong antibacterial activity, it has been found that long-term exposure to a contaminated environment reduces its antibacterial activity and that drug contamination can be heavily affected not only by environmental but also human effects. Therefore, the use of aseptic drugs is necessary, and stopping the reuse of the drug is a way to prevent complications, including infection.
Agar
;
Bacteria
;
Chlorhexidine
;
Drug Contamination
;
Fatal Outcome
;
Humans
;
Lidocaine
;
Operating Rooms
;
Outpatients
;
Saliva
;
Skin
;
Viridans Streptococci
9.Validation Study of an Operational Tolerance Signature in Korean Kidney Transplant Recipients.
Yu Ho LEE ; Jung Woo SEO ; Yang Gyun KIM ; Ju Young MOON ; Jin Sug KIM ; Kyung Hwan JEONG ; Bo mi KIM ; Kyoung Woon KIM ; Chul Woo YANG ; Chan Duck KIM ; Jae Berm PARK ; Yeong Hoon KIM ; Byung Ha CHUNG ; Sang Ho LEE
Immune Network 2018;18(5):e36-
Operational tolerance (OT), defined as maintaining stable graft function without immunosuppression after transplant surgery, is an ideal goal for kidney transplant recipients (KTRs). Recent investigations have demonstrated the distinctive features of B cells, T cells, and dendritic cell-related gene signatures and the distributions of circulating lymphocytes in these patients; nonetheless, substantial heterogeneities exist across studies. This study was conducted to determine whether previously reported candidate gene biomarkers and the profiles of lymphocyte subsets of OT could be applied in Korean KTRs. Peripheral blood samples were collected from 153 patients, including 7 operationally tolerant patients. Quantitative real-time PCR and flow cytometry were performed to evaluate gene expression and lymphocyte subsets, respectively. Patients with OT showed significantly higher levels of B cell-related gene signatures (IGKV1D-13 and IGKV4-1), while T cell-related genes (TOAG-1) and dendritic cell-related genes (BNC2, KLF6, and CYP1B1) were not differentially expressed across groups. Lymphocyte subset analyses also revealed a higher proportion of immature B cells in this group. In contrast, the distributions of CD4⁺ T cells, CD8⁺ T cells, mature B cells, and memory B cells showed no differences across diagnostic groups. An OT signature, generated by the integration of IGKV1D-13, IGKV4-1, and immature B cells, effectively discriminated patients with OT from those in other diagnostic groups. Finally, the OT signature was observed among 5.6% of patients who had stable graft function for more than 10 years while on immunosuppression. In conclusion, we validated an association of B cells and their related signature with OT in Korean KTRs.
B-Lymphocytes
;
Biomarkers
;
Flow Cytometry
;
Gene Expression
;
Humans
;
Immunosuppression
;
Kidney Transplantation
;
Kidney*
;
Lymphocyte Subsets
;
Lymphocytes
;
Memory
;
Precursor Cells, B-Lymphoid
;
Real-Time Polymerase Chain Reaction
;
RNA, Messenger
;
T-Lymphocytes
;
Transplant Recipients*
;
Transplants
10.Comparison of standard-setting methods for the Korean Radiological Technologist Licensing Examination: Angoff, Ebel, bookmark, and Hofstee
Janghee PARK ; Duck Sun AHN ; Mi Kyoung YIM ; Jaehyoung LEE
Journal of Educational Evaluation for Health Professions 2018;15(1):32-
PURPOSE: This study aimed to compare the possible standard-setting methods for the Korean Radiological Technologist Licensing Examination, which has a fixed cut score, and to suggest the most appropriate method. METHODS: Six radiological technology professors set standards for 250 items on the Korean Radiological Technologist Licensing Examination administered in December 2016 using the Angoff, Ebel, bookmark, and Hofstee methods. RESULTS: With a maximum percentile score of 100, the cut score for the examination was 71.27 using the Angoff method, 62.2 using the Ebel method, 64.49 using the bookmark method, and 62 using the Hofstee method. Based on the Hofstee method, an acceptable cut score for the examination would be between 52.83 and 70, but the cut score was 71.27 using the Angoff method. CONCLUSION: The above results suggest that the best standard-setting method to determine the cut score would be a panel discussion with the modified Angoff or Ebel method, with verification of the rated results by the Hofstee method. Since no standard-setting method has yet been adopted for the Korean Radiological Technologist Licensing Examination, this study will be able to provide practical guidance for introducing a standard-setting process.
Education
;
Licensure
;
Methods
;
Technology, Radiologic

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