• The Korean Journal of Nuclear Medicine
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• v.14 no.2
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• pp.1-9
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• 1980

혈액질환(血液疾患), 특히 용혈성빈혈(溶血性貧血)을 수반(隨伴)한 경우(境遇)에 적혈구(赤血球)의 생성(生成), 파괴과정(破壞過程)을 정확히 파악하는 것은 빈혈(貧血)의 발생기전(發生機轉) 및 병인(病因), 치료(治療), 예후(豫後) 결정(決定)에 매우 중요(重要)하다. 적혈수명측정법(赤血壽命測定法)은 최근(最近) 방사성(放射性)동위원소(同位元素)를 이용(利用)한 방법(方法)이 소개된 이래 널리 시행(施行)되어 왔다. 그러나 그 방법(方法) 및 결과(結果) 해석(解釋)에 표준화(標準化)가 되어 있지 않았던 중 1971년 ICSH (International Committee for Standardization in Hematology)에서 expert panel을 갖고 ICSH 추천 방법(方法)을 발표(發表)하였고, 본지(本誌)에서도 그 내용(內容)을 게재(揭載)한 바 있다. 1980년 ICSH는 전문기관 및 전문가의 협조(協調)를 얻어 다시 expert panal을 갖은 후 1971년에 추진한 적혈구수명측정법(赤血球壽命測定法)의 일부(一部)를 수정(修正)하여 ICSH의 표준방법(標準方法)으로 발표(發表)하였다. 개정(改正)된 표준방법(標準方法)과 1971년 ICSH추친 방법(方法)과의 차이(差異)는 다음과 같다. $^{51}Cr$표지방법중(標識方法中) 참고방법(參考方法)(Reference method)인 ACD법(法)에 수정(修正)을 가하여, ACD solution 구성성분(構成成分)이 차이(差異)가 있으며, 표지(標識)$^{51}Cr$의 양(量)을 체중당(體重當) $1.5{\mu}Ci$에서 $0.5{\mu}Ci$로 제한(制限)시켰다. 투여방법(投與方法)에 대한 언급 특히 투여하는 표지적혈구(標識赤血球)의 용적을 정확하게 측정 하기 위한 방법 4가지를 추가하였고, 검체준비(檢體準備) 과정중(過程中)의 pipet error를 방지(防止)하기위해 일정(一定)한 형태의 pipet을 사용(使用)하며, 1ml의 tuterculin syringe는 사용(使用)하지 않기로 하였다. 또한 결과분석시(結果分析時) 혈구용적(血球容積)의 항정성(恒定性)을 위해 Sodium pertectnetate($^{99m}Tc$)를 이용(利用)해 혈구용적(血球容積)을 반복(反復)해 측정(測定)하도록 하였으며 이때 사용(使用)하는 방사성동위원소(放射性同位元素)는 $^{32}P$ 대신 $^{99m}Tc$로 하였다. 결과해석시(結果解釋時) IgG 항체(抗體) 또는 IgM 항체(抗體)에 따른 차이점(差異點)에 대한 고려가 추가(追加)되었다. ICSH와 국제혈액학회(國際血液學會)에서 수정(修正)된 ICSH 표준방법(標準方法)에 의한 적혈수명측정법(赤血壽命測定法)을 널리 소개(紹介)하여 결과(結果)의 표준화(標準化)를 기하고자 연관잡지(聯관(關)雜誌)에 게재(揭載)할 것을 요청(要請)하였기에 전문(全文)을 본지(本誌)에 소개(紹介)하고자 한다.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.3
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• pp.132-142
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• 2023

Human leukocyte antigen (HLA) typing was performed in the diagnostic immunology laboratory of the Seoul National University Hospital. Among 611 HLA-DR tests, specific bead reactions suspected of being false positive and false negative in Lot 20 reagents were found. Therefore, we aimed to identify the factors causing cut-off corrections by examining cases where cut-off corrections were not made for 533 test results and cases where cut-off corrections were made for 78 cases after the cut-off corrections of specific beads. Frequency analysis was conducted to verify the demographic characteristics, and descriptive statistics were used to assess the humidity in the laboratory as a variable. Cross-tabulation was done to examine the association between cut-off corrections and demographic characteristics. Independent samples t-tests were conducted to verify the difference in humidity based on cut-off corrections. Finally, logistic regression analysis was conducted to examine the relationship between humidity levels and the rate of cut-off corrections, and results showed as the humidity level in the laboratory highs, the number of cut-off corrections decreased by a factor of 0.986. This suggests cut-off corrections rate increases when the humidity lowers. Therefore, it indicates that humidity in the laboratory is also a factor that affects HLA typing results.

• Laboratory Medicine Online
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• v.1 no.2
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• pp.110-114
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• 2011

There have been a few reports of hemophagocytic lymphohistiocytosis (HLH) with chromosomal abnormalities. Clonal chromosomal abnormalities in HLH patients are usually found in association with hematologic malignancies and rarely with epstein-barr virus (EBV) infection. Here, we report a fatal case of HLH with clonal karyotype abnormalities. A 75-yr-old man was admitted with persistent anorexia and high fever. Laboratory data revealed pancytopenia, hypofibrinogenemia, hyperferritinemia, prolonged prothrombin time and activated partial thromboplastin time, and marked elevated level of serum transaminases. In real time-PCR using whole blood, EBV DNA was not detected but cytomegalovirus (CMV) DNA was detected. The bone marrow aspiration smear showed hyperplasia of mature histiocytes with prominent hemophagocytosis. In chromosomal analysis of bone marrow aspirates, complex chromosomal abnormalities were found. In spite of steroid pulse therapy and antibiotic treatment, he died of disseminated intravascular coagulopathy.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.23 no.1
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• pp.17-24
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• 2023

Purpose: In the past, detection of metabolic abnormalities in plasma amino acid (PAA) and urine organic acid (UOA) has been widely used to diagnose clinical mitochondrial diseases, such as mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS). In this study, the diagnostic values of PAA and UOA were reviewed, and their effectiveness in the diagnosis of MELAS was examined retrospectively. Methods: Blood and urine samples at the time of diagnosis were collected from all clinically diagnosed MELAS patients (n=31), and PAA and UOA tests were performed. All samples were collected in a fasting state to minimize artifacts in the results. The difference in the ratio of abnormal metabolites of PAA and UOA at initial diagnosis was statistically compared between the MELAS with genetic confirmation (n=19, m.3243A>G mutation) and MELAS without genetic confirmation (n=12) groups. The MELAS without genetic confirmation group was used as control. Results: Comparison of PAA and UOA between the two groups revealed that no abnormal metabolites showed characteristic differences between gene-confirmed MELAS patients with and those without genetic confirmation. Conclusions: Abnormal values of metabolites in PAA or UOA might be useful as a screening test but are not sufficient to diagnose MELAS patients.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.2
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• pp.82-92
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• 2023

Urine sediments are performed by a microscopic examination of centrifuged urine by medical technologists. This study examined different urine sediment preparation procedures. The 107 fresh urine specimens that tested positive from white blood cells (WBCs) and red blood cells (RBCs) in the urine dipstick test and the cobas u 701 analyzer, respectively, were selected for manual microscopy. This study evaluated an automated urine sediment analyzer and three manual microscopy methods for WBCs and RBCs. The methods were performed according to the test guidelines. The coefficients of determination between the cobas u 701 analyzer and the Korean Association of Quality Assurance for Clinical Laboratory (KAQACL) for WBCs and RBCs were r2=0.977 and r2=0.970, respectively. The concordance rates between the cobas u 701 analyzer and KAQACL for WBCs and RBCs were 74.8% and 77.6%, respectively. A good correlation and concordance with the automatic analyzer were shown when the specimens were prepared and examined using the KAQACL method. Consequently, the differences in the urine sediment preparation procedures affected the sediment concentrations, influencing the cell number per high power field (HPF).

• Analytical Science and Technology
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• v.19 no.1
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• pp.107-114
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• 2006

Early diagnosis and medical intervention are critical for the treatment of patients with metabolic disorders. A rapid analytical method was developed for simultaneous quantification of organic acids and amino acids in urine without labor-intensive pre-extraction procedure showing high sensitivity and specificity. A new method consisted of simple two-step trimethylsilyl (TMS)-trifluoroacetyl (TFA) derivatization using GC/MS-selective ion monitoring (SIM). Filter paper urine specimens were dried under nitrogen after being fortified with internal standard (tropate) in a mixture of distilled water and methanol. Methyl orange was added to the residue as indicator reagent. Silyl derivative of carboxylic functional group was followed by trifluoroacetyl derivative for amino functional group. N-methyl-N-(trimethylsilyl-trifluoroacetamide) and N-methyl-bistrifluoroacetamide were consecutively added and heated for 15-20 min at $65^{\circ}C-70^{\circ}C$, for TMS-TFA derivative, respectively. This reactant was analyzed by GC/MS-SIM. Linear dynamic range showed 0.001-50 mg with the detection limit of (S/N=3) 10-200 ng, and the quantification limit of 80-900 ng in urine. Correlation coefficient of regression line was 0.994-0.998. When the method was applied to the patients 'urine, it clearly differentiated the normal from the patient with metabolic disorder. The study showed that the developed method could be the method of choices in rapid and sensitive screening for organic aciduria and amino acidopathy.

• Journal of Food Hygiene and Safety
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• v.38 no.5
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• pp.297-304
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• 2023

Domoic acid (DA), a neurotoxin produced naturally by diatoms, is responsible for incidents of amnesic shellfish poisoning. In this study, a modified analytical method was established to determine domoic acid in seafood using solid phase extraction cleanup and optimizing the amount of sample and extraction solvent to reduce interference effects. The modified method using high-performance liquid chromatography with ultraviolet detection was validated using three seafood matrices (mussel, red snow crab, and anchovy) at three concentrations (1, 2, and 4 mg/kg) and compared to the Food Code method. Compared to the Food Code method, the modified method showed better performance in terms of linearity (R²>0.999), detection limit (0.02-0.03 mg/kg), quantification limit (0.05-0.09 mg/kg), intra-/inter-day accuracy (86.2-100.4%), and intra-/inter-day precision (0.2-4.0%). Furthermore, the method was successfully applied for the analysis of 87 seafood samples marketed in Korea, and DA was detected at a low concentration of 140 ㎍/kg in one anchovy sample. These results suggest that the modified method can be used for routine determination of DA in seafood.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.2
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• pp.115-124
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• 2024

The emergence and spread of Staphylococcus aureus, which is resistant to quinolone antibacterial agents, has made it difficult to treat infectious diseases. Accordingly, this study examined the molecular epidemiological characteristics of quinolone-resistant S. aureus (QRSA) to obtain helpful data for treatment. Mutations in mecA and SCCmec typing, gyrA, and gyrB genes were investigated for QRSA strains isolated from the blood culture specimens at a general hospital in Daejeon Metropolitan City. The ciprofloxacin-resistant strains in SCCmec typing were II (44 strains, 73%), IVa (five strains, 8%), III, and V (one strain, 2%); the non-typeable strains (11 strains, 18%), and levofloxacin (LVX) and moxifloxacin (MXF) strains were II (44 strains, 73%), IVa (five strains, 8%), III, and V (one strain, 2%); the non-typeable strains were 10 (17%). In both gyrA and gyrB regions, there were 58 mutations, or 96.7%. In LVX, there were 56 mutations or 93.3%, and in MXF, there were 57 mutations or 95%. Twelve mutations, six mutations each in gyrA and gyrB, were identified for the QRSA strain. The resistance rate for the quinolone antibiotics of QRSA studied was approximately 98%, and 12 mutations, six each in gyrA and gyrB, were identified in the QRSA strain. Therefore, the rational use of antibiotics needs to be improved.

• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.610-619
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• 2020

Purpose The study aimed to investigate the role of Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) in predicting incidental prostate cancer (PCa) or urothelial carcinoma (UCa) extension in urinary bladder (UB) cancer patients. Materials and Methods A total of 72 UB cancer patients who underwent radical cystoprostatectomy and 3 Tesla multiparametric MRI before surgery were enrolled. PI-RADS v2 ratings were assigned by two independent radiologists. All prostate specimens were examined by a single pathologist. We compared the multiparametric MRI findings rated using PI-RADS v2 with the pathologic data. Results Of the 72 UB cancer patients, 29 had incidental PCa (40.3%) and 20 showed UCa extension (27.8%), with an overlap for 3 patients. With a score of 4 as the cut-off value for predicting incidental PCa, the diagnostic accuracy was 65.3%, specificity was 90.7%, and positive predictive value (PPV) was 66.7%. The diagnostic accuracy for incidental UCa extension was 47.2%, specificity was 92.3%, and PPV was 83.3%. Conclusion Despite the low diagnostic accuracy, the PPV and specificity were relatively high. Therefore, PI-RADS v2 scores of 1, 2, or 3 may help exclude the probability of incidental PCa or UCa extension.

• Pediatric Infection and Vaccine
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• v.30 no.3
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• pp.152-158
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• 2023

Staphylococcus aureus (SA) is a common cause of skin and soft tissue infections. Panton-Valentine leukocidin (PVL) toxin-producing strain of SA has been discovered worldwide and is known to cause serious infections. However, reports of neonatal infections caused by PVL-positive SA are rare. Here, we report a case of severe skin and soft tissue infection caused by PVL-positive SA in a 7-day-old neonate. The patient was admitted to the emergency room with a history of fever for one day, tenderness, and sensation of buttocks heating. The infant presented with fever, tachycardia, poor general health, progressive tenderness, and edema of the buttocks on the day of admission. Ultrasonography and magnetic resonance imaging revealed necrotizing fasciitis involving the skin, soft tissue, and muscles. Specimens drained from the buttock lesions confirmed the presence of PVL-positive methicillin-resistant SA (MRSA), and there was no bacteremia. She recovered after one month of intravenous antibiotics and surgical drainages. One month after discharge, she was rehospitalized for otitis externa and was infected with MRSA again. Considering the PVL-positive strain, the patient was treated with intravenous linezolid and dressing. The patient underwent decolonization therapy in a 0.5% chlorhexidine bath and recovered completely without sequelae. This case suggests that aggressive drainage and antibiotic treatment are essential for PVL-producing MRSA infections, and additional decolonization is needed to prevent recurrence and community spread.