Current Status of Erythrocyte Sedimentation Rate Test and Results According to Methods in Korea

Kibum Jeon,Young Min Kim,Young Kyung Lee 대한임상검사정도관리협회 2022 Journal of Laboratory Medicine And Quality Assuran Vol.44 No.3

Background: The erythrocyte sedimentation rate (ESR) test is one of the most frequently performed in clinical laboratories. In addition to traditional ESR methods such as the Westergren and Wintrobe methods, these methods have been diversified in recent years. We investigated the current status of ESR methods in Korea and the distribution of ESR results according to the methods based on the external quality assessment (EQA) data of the Korean Association of External Quality Assessment Service. Methods: Data from the ESR EQA, conducted twice a year from 2018 to 2021, were collected. We investigated the ESR methods, equipment usage status, and ESR results according to the methods. We also analyzed trends in proficiency test results by year. Results: The alternate method was the most frequently used ESR method in Korea (56.0%). The distribution of interlaboratory coefficients of variation (CVs) was 21.4%±14.3% (mean±standard deviation) for the Wintrobe method, 33.4%±12.8% for the Westergren method, and 22.8%±19.7% for the modified Westergren method, with no statistically significant difference between the three methods. The interlaboratory CVs of the alternate method were significantly lower than those of all other methods (6.2%±2.2%, P <0.001). The interlaboratory CVs showed a tendency to gradually decrease by year for all methods. Conclusions: Automated ESR methods are used in most laboratories in Korea. The interlaboratory CVs were lowest for the alternate method and tended to decrease as EQA was implemented. The ESR EQA is expected to improve the quality of the ESR.

Annual Report of the Korean Association of External Quality Assessment Service on Routine Hematology (2020)

Kibum Jeon,Young Min Kim,이영경,Routine Hematology Program of Korean Association of External Quality Assessment Service 대한임상검사정도관리협회 2021 Journal of Laboratory Medicine And Quality Assuran Vol.43 No.1

Two trials were conducted with proficiency tests for complete blood count (CBC) and blood cell morphology as part of the 2020 Routine Hematology Program of the Korean Association of External Quality Assessment Service (KAEQAS). Three different control samples were sent for CBC testing, and two blood cell morphology images were posted on the KAEQAS website during each trial. The mean response rates of the 1,790 participating laboratories were 98.8% and 34.7% for CBC testing and blood cell morphology, respectively. The distribution of equipment for CBC testing was comparable to that of the previous year. The coefficient of variation (CV) ranges were determined as 2.9%–3.5%, 1.8%–2.8%, 1.4%–2.8%, 4.6%–5.5%, and 5.2%–7.9% for white blood cell counts, red blood cell counts, hemoglobin, hematocrit, and platelet counts, respectively. The concordance rate of blood cell morphology tests ranged from 58.8% to 99.2%. In 2020, the number of participating laboratories was higher than that in 2019. The CVs of CBC results in 2020 were similar to those of 2019.

Quantification of Cell-Free DNA: A Comparative Study of Three Different Methods

Kibum Jeon,Jiwon Lee,이지수,Miyoung Kim,Han-Sung Kim,강희정,Young Kyung Lee 대한임상검사정도관리협회 2019 Journal of Laboratory Medicine And Quality Assuran Vol.41 No.4

Background: Cell-free DNA (cfDNA) provides unique potential as a biomarker for cancer patients or in the field of prenatal care. Following extraction from plasma, cfDNA should be quantified before downstream analysis. The standardization of the quantification methods is essential for application of these techniques to laboratory practice. We aimed to compare three different quantification methods (spectrophotometry, fluorometry, and the electrophoresis-based method) and to determine the contributor(s) to the differences, if any. Methods: A total of 135 plasma samples obtained from cancer patients (n=71) and normal individuals (n=15) and cfDNA were extracted from the samples. The extracted cfDNA was quantified using three different methods: NanoDrop spectrophotometry, Quantus fluorometry, and the electrophoresis-based 4200 TapeStation method. Results: NanoDrop exhibited the highest estimates (median, 12.3 ng/uL). The estimates of Quantus (median, 0.33 ng/uL) were higher than those of 4200 TapeStation (median, 0.22 ng/ uL). Quantus and TapeStation were significantly correlated (r =0.802, P<0.001). The Bland- Altman plot showed a positive bias of 0.24 ng/uL for Quantus compared with TapeStation. The difference between Quantus and TapeStation values demonstrated a significantly moderate correlation with the amount of high molecular weight DNA (r =0.357, P<0.001). Conclusions: Nanodrop is considered as a non-specific method of cfDNA quantification. Quantus depicted more specific quantification compared to Nanodrop; however, TapeStation may be used in parallel or as a complementary method as it enables to determine the size distribution of DNA fragments.

국내 도로 전자파 환경에 관한 연구

전인학(Inhak Jeon),노형길(Hyunggil Noh),권석태(Suktai Kwun),정기범(Kibum Jung) 한국통신학회 2016 한국통신학회 학술대회논문집 Vol.2016 No.11

Comparison of Body Fluid Diferential Counts Using a Manual Counting Method or an Automated Hematology Analyzer

Jiwon Lee,Kibum Jeon,Jisoo Lee,Miyoung Kim,Han-Sung Kim,Hee Jung Kang,Young Kyung Lee 대한임상검사정도관리협회 2020 Journal of Laboratory Medicine And Quality Assuran Vol.42 No.1

Background: Two methods of counting cells in body fluids were compared; manual counting using a Neubauer chamber, and automated cell counting using an XN-350 hematology analyzer.Methods: Cells from 32 body fluid samples were counted by manual examination and by an automated analyzer. Total cells (TC), white blood cells (WBC), red blood cells (RBC), polymorphonuclear leukocytes (PMN), mononuclear leukocytes (MN), neutrophils, lymphocytes, monocytes, and eosinophils were each counted by both methods. The results were compared using the Pearson correlation test, Bland-Altman regression analysis, and Passing-Bablok regression analysis.Results: The two methods showed very strong correlation in TC, WBC, RBC, PMN, and MN counts, strong correlation in % neutrophils, and % lymphocytes, and weak correlation in % monocytes and % eosinophils. Using Bland-Altman regression analysis, the mean biases for TC, WBC, and RBC were -270, -257.4, and -1,256.09, respectively, and 0.15 for PMN and MN. Research parameters were compared as well: mean biases were -1.31, -2.46, -5.16, and -3.58 for % neutrophils, % monocytes, % lymphocytes, and % eosinophils, respectively. Passing-Bablok regression equations were y=1.039x+20, y=1.037x+19, y=1.259x+0.0, y=0.983x+1.541, and y=0.983x+0.125 for TC, WBC, RBC, PMN, and MN, respectively. The equations were y=0.955x+2.194 for % neutrophils, y=0.965x+1.184 for % monocytes, y=1.003x+0.161 for % lymphocytes, and y=x+0.75 for % eosinophils.Conclusions: WBC differential count results performed by an automated hematology analyzer generally show good correlation with our reference method, Neubauer chamber counting.

Changing Genotypic Distribution, Antimicrobial Susceptibilities, and Risk Factors of Urinary Tract Infection Caused by Carbapenemase-Producing Pseudomonas aeruginosa

Jeong Seri,Jeon Kibum,Lee Nuri,Park Min-Jeong,Song Wonkeun 대한진단검사의학회 2024 Annals of Laboratory Medicine Vol.44 No.1

Background: Carbapenem-resistant Pseudomonas aeruginosa (CrPA) is a leading cause of healthcare-associated urinary tract infections (UTIs). Carbapenemase production is an important mechanism that significantly alters the efficacy of frequently used anti-pseudomonal agents. Reporting the current genotypic distribution of carbapenemase-producing P. aeruginosa (CPPA) isolates in relation to antimicrobial susceptibility, UTI risk factors, and mortality is necessary to increase the awareness and control of these strains. Methods: In total, 1,652 non-duplicated P. aeruginosa strains were isolated from hospitalized patients between 2015 and 2020. Antimicrobial susceptibility, carbapenemase genotypes, risk factors for UTI, and associated mortality were analyzed. Results: The prevalence of carbapenem-non-susceptible P. aeruginosa isolates showed a decreasing trend from 2015 to 2018 and then increased in the background of the emergence of New Delhi metallo-β-lactamase (NDM)-type isolates since 2019. The CPPA strains showed 100.0% non-susceptibility to all tested antibiotics, except aztreonam (94.5%) and colistin (5.9%). Carbapenems were identified as a risk and common predisposing factor for UTI (odds ratio [OR]=1.943) and mortality (OR=2.766). Intensive care unit (ICU) stay (OR=2.677) and white blood cell (WBC) count (OR=1.070) were independently associated with mortality. Conclusions: The changing trend and genetic distribution of CPPA isolates emphasize the need for relentless monitoring to control further dissemination. The use of carbapenems, ICU stay, and WBC count should be considered risk factors, and aggressive antibiotic stewardship programs and monitoring may serve to prevent worse outcomes.

Genotypic Distribution and Antimicrobial Susceptibilities of Carbapenemase-Producing Enterobacteriaceae Isolated From Rectal and Clinical Samples in Korean University Hospitals Between 2016 and 2019

Jeong Seri,이누리,Park Min-Jeong,Jeon Kibum,Kim Han-Sung,Kim Hyun Soo,Kim Jae-Seok,송원근 대한진단검사의학회 2022 Annals of Laboratory Medicine Vol.42 No.1

Background: The emergence of carbapenemase-producing Enterobacteriaceae (CPE) represents a major clinical problem. Recently, the occurrence of CPE has increased globally, but epidemiological patterns vary across region. We report the trends in the genotypic distribution and antimicrobial susceptibility of CPE isolated from rectal and clinical samples during a four-year period. Methods: Between January 2016 and December 2019, 1,254 nonduplicated CPE isolates were obtained from four university hospitals in Korea. Carbapenemase genotypes were determined by multiplex real-time PCR. Antimicrobial susceptibility was profiled using the Vitek 2 system (bioMérieux, Hazelwood, MO, USA) or MicroScan Walkaway-96 system (Siemens West Sacramento, CA, USA). The proportions of carbapenemase genotypes and nonsusceptibility were analyzed using Pearson’s chi-square test. Results: Among the 1,254 CPE isolates, 486 (38.8%), 371 (29.6%), 357 (28.5%), 8 (0.6%), 8 (0.6%), and 24 (1.9%) were Klebsiella pneumoniae carbapenemase (KPC), oxacillinase (OXA)-48-like, New Delhi metallo-β-lactamase (NDM), imipenemase (IMP), Verona integron-encoded metallo-β-lactamase (VIM), and multiple producers, respectively. The predominant species was K. pneumoniae (72.6%), followed by Escherichia coli (6.5%). More than 90% of the isolates harboring KPC, NDM, and OXA-48-like were nonsusceptible to cephalosporins, aztreonam, and carbapenems. Conclusions: The impact of CPE is primarily due to KPC-, NDM-, and OXA-48-like-producing K. pneumoniae isolates. Isolates carrying these carbapenemase are mostly multidrug-resistant. Control strategies based on these genotypic distributions and antimicrobial susceptibilities of CPE isolates are required.

육군 장교가 인식하는 재능(talent)평가지표에 대한 요구분석

현영섭 ( Hyun Youngsup ),권기범 ( Kwon Kibum ),최유연 ( Choi Yuyeon ),전형구 ( Jeon Hyongku ),조대연 ( Cho Daeyeon ) 한국인력개발학회 2021 HRD연구 Vol.23 No.2

본 연구의 목적은 미래 육군의 재능 기반 인재육성 및 관리 환경을 조성하기 위해 육군 장교의 능력과 자질을 식별할 수 있는 재능평가지표에 대한 요구를 실증적으로 분석하는 것이다. 연구목적을 달성하기 위해 재능관련 선행연구 검토, 전문가 의견 수렴, 육군간부 설문조사의 절차를 적용하였다. 선행연구 검토와 전문가 의견 수렴을 통해 육군 간부 재능지표를 도출하였다. 도출된 재능지표를 활용하여 요구분석 설문지를 구성하였다. 요구분석을 위해 육군 간부 521명으로부터 설문조사 데이터를 수집하였다. 요구분석은 t검증, Borich의 요구도 분석, LFF 모델을 활용하여 실시되었다. 분석결과는 다음과 같다. 첫째, 육군 간부 전체에게 요구수준이 높은 재능평가지표는 42개 중 14개였다. 둘째. 육군간부의 계급에 따라 요구되는 재능평가지표 중 7개 지표는 모든 계급에서 요구수준이 높았다. 셋째, 육군 간부의 요구되는 재능평가지표 중 일부는 계급에 따라 차이가 있었다. 이상의 분석결과를 토대로 논의와 시사점을 제시하였다. The purpose of this study is to empirically analyze the needs of talent evaluation indicators to identify the capabilities and qualities of Army officers in order to create a future talent-based development and management environment for the Army. In order to achieve the purpose of the study, through the review of prior research and gathering expert opinions, the talent index for Army officials was derived. Based on the index, the questionnaire was constructed for need analysis of talent indicators. Survey data were collected from 521 Army officers. Need analysis was conducted by t-test, Borich's fomular, and LFF model. The findings are as follows. First, there were 14 out of 42 talent evaluation indicators with high priorities. Second, seven talent evaluation indicators are required across all classes. Third, some of the talent evaluation indicators are differed by the class. Based on these findings, some discussions and implications were presented.

AMR방식 SAS와 Optical방식 SAS의 Hysteresis 특성 비교에 관한 연구

남철(Chul Nam),전민석(Minseok Jeon),표재우(Jaewoo Pyo),박기범(Kibum Park),이석우(Seagwoo Lee),이대성(Daesung Lee) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

In this paper, we confirmed Hysteresis characteristic in absolute angle detect SAS(Steering Angle Sensor) with AMR (Anisotropic Magneto Resistance) type sensor and implemented back-lashless Optical Type SAS with symmetrical PWM code to improve Hysteresis. We expected good result at Hysteresis characteristic but faced problems such as roter’s gap with the steering shaft and delay time caused by angle calculation algorithm. If we solve these problems Optical type SAS will become a better Steering Angle Sensor.