Estimating the Biases of the Korean National Cholesterol Proficiency Test

It is recommended that clinical laboratories keep the bias of serum total cholesterol analysis at <= 3.0% compared to a reference method. In Korea, national cholesterol proficiency testing has long been available, but there has been little information about the magnitude of analytical bias. The authors calculated the bias of the peer group mean for Korea`s national cholesterol proficiency test through an indirect approach that overcomes the potential matrix effect of proficiency test materials. One laboratory was selected among the proficiency test participants to represent Korean laboratories. Total cholesterol levels of six fresh serums spanning a wide range of concentrations were measured by the representative laboratory and three reference laboratories. The relationship between the proficiency test mean and the reference method mean was established by linear regression analysis. The peer group mean of the proficiency test was calculated to have a bias of +2.4 to +2.5% at the medical decision levels. When grouped by instrument and reagent, 29 to 66% of the laboratories showed biases < 3.0%. Thus it was determined that the peer group mean of the Korean cholesterol proficiency test has an acceptable level of positive bias. The indirect approach used in this study provides a practical model for estimating cholesterol analytical bias for proficiency testing.Ross JW, 1998, ARCH PATHOL LAB MED, V122, P587MYERS GL, 2000, CLIN CHEM, V46, P762Cleeman JI, 2001, JAMA-J AM MED ASSOC, V285, P2486, DOI 10.1001/jama.285.19.2486BROTONS C, 2003, EUR J GEN PRACT, V9, P124SHIN HH, 2003, KOR J LIPIDOL, V12, P226MIN WK, 2006, J LAB MED QUAL ASSUR, V28, P1MIN WK, 2007, J LAB MED QUAL ASSUR, V29, P1Teramoto T, 2007, J ATHEROSCLER THROMB, V14, P45MIN WK, 2008, J LAB MED QUAL ASSUR, V30, P1Stockl D, 1996, CLIN CHEM, V42, P469ROSS JW, 1993, ARCH PATHOL LAB MED, V117, P393*NIH, 1993, NIH PUBL*BUR INT POIDS MES, 2009, DAT HIGH ORD REF MAT*CDCP DIV LAB SCI, 2009, CHOL REF METH LAB NEELLERBE P, 1990, CLIN CHEM, V36, P370

Performance Evaluation of the GlucoDr Plus Glucometer

Background: Because strict glucose control is important for reducing the complications of diabetes, the self-monitoring of blood glucose is one of the fundamental treatment modalities. Many glucometers have been developed. In the present study, we evaluated a new glucometer: GlucoDr (TM) Plus (Allmedicus, Anyang, Gyeonggi-do, Republic of Korea). Methods: The evaluation was performed based on Clinical and Laboratory Standards Institute guidelines. Interferences by ascorbic acid, uric acid, maltose, and acetaminophen were examined, and the performance of the unit was compared to those of six other glucometers. The effects of hematocrit, of oxygen partial pressure (PaO(2)), and of multiple users were also evaluated. Results: Within-run, between-run, between- day, and total imprecision (coefficients of variation) were 0.99-4.98%. Satisfactory linearity was found for glucose concentrations of 32.5-786.5 mg/dL (R(2) = 0.9985). A comparison with the reference laboratory method showed close concordance over the entire range of concentrations evaluated (R(2) = 0.9869). No significant effects were noted due to added interferents, hematocrit, and PaO(2). Conclusions: The GlucoDr Plus showed acceptable performance in terms of precision and linearity. It was minimally affected by various interferents. GlucoDr Plus is suitable for the self-monitoring of blood glucose by patients with diabetes.Schleis TG, 2007, PHARMACOTHERAPY, V27, P1313Tsujimura S, 2006, BIOSCI BIOTECH BIOCH, V70, P654D`Orazio P, 2006, CLIN CHEM LAB MED, V44, P1486, DOI 10.1515/CCLM.2006.275Nathan DM, 2005, NEW ENGL J MED, V353, P2643Wild S, 2004, DIABETES CARE, V27, P1047*CLIN LAB STAND I, 2004, EP5A2 CLSI*CLIN LAB STAND I, 2003, EP6A CLSI*INT ORG STAND, 2003, 151972003E ISO*CLIN LAB STAND I, 2002, EP7A CLISTang ZP, 2001, CRIT CARE MED, V29, P1062Tang ZP, 2000, AM J CLIN PATHOL, V113, P75Turner RC, 1998, LANCET, V352, P837*CLIN LAB STAND I, 1995, EP9A CLSI1994, DIABETES CARE, V17, P81MERENSTEIN GB, 1993, PEDIATRICS, V92, P4741993, N ENGL J MED, V329, P977BARRETT AE, 1979, J CLIN PATHOL, V32, P893

The Relationship between Lewis/Secretor Genotypes and Serum Carbohydrate Antigen 19-9 Levels in a Korean Population

Background : The Lewis histo-blood group system consists of 2 major antigens-Le(a) and Le(b)-and a sialyl Lewis antigen-carbohyd rate antigen (CA) 19-9. We investigated the distribution of Lewis genotypes and evaluated the relationship between the Lewis/Secretor genotypes and the serum level of CA 19-9 in a Korean population to identify whether the serum CA 19-9 levels are influenced by the Lewis/Secretor genotypes. Methods : The study included 242 individuals who had no malignancies. Lewis genotyping was performed for the 59T>G, 508G>A and 1067T>A polymorphic sites. The Secretor genotype was determined through analysis of the 357C>T and 385A>T polymorphic sites and the fusion gene. Serum CA 19-9 level was analyzed using an electrochemiluminescence immunoassay. Results : Individuals carrying the 3 common genotypes-Le/Le, Le/le(59,508), and Le/le(59,1067)-accounted for 95% of the study population. In the Korean population, the allelic frequencies of Le, Le(59)le(59,508) and le(59,1067) were 0.731, 0.010, 0.223, and 0.035, respectiveiy. We found a significant difference in serum CA 19-9 concentrations among the 9 LewislSecretor genotype groups (P<0.001). The serum CA 19-9 levels in subjects with genotype groups 1 and 2 (Le/- and se/se) were higher than those with genotype groups 3-6 (Le/- and Se/-; 15.63 vs 6.64 kU/L, P<0.001). Conclusions : Le/Le(59,508), and Le/le(59,1067) are frequent Lewis genotypes in Koreans. Because serum CA 19-9 levels are significantly influenced by the LewislSecretor genotypes, caution is suggested when interpreting the serum CA 19-9 levels. (Korean J Lab Med 2010;30:51-7)SONG SY, 2008, KOREAN J HEMATOL, V43, P34Park KU, 2005, ANN HEMATOL, V84, P656, DOI 10.1007/s00277-005-1041-5Hayashi N, 2004, PATHOBIOLOGY, V71, P26, DOI 10.1159/000072959Hamajima N, 2002, J MOL DIAGN, V4, P103HAMAJIMA N, 2002, GASTRIC CANCER, V5, P194Liu TC, 2000, ANN HEMATOL, V79, P599Lamerz R, 1999, ANN ONCOL, V10, P145Vestergaard EM, 1999, CLIN CHEM, V45, P54Liu YH, 1999, J HUM GENET, V44, P181Kim MJ, 2002, YONSEI MED J, V43, P427SHIBATA A, 2003, GASTRIC CANCER, V6, P8Liu YH, 1999, J FORENSIC SCI, V44, P82Liu YH, 1998, HUM GENET, V103, P204Pang H, 1998, HUM GENET, V102, P675Narimatsu H, 1998, CANCER RES, V58, P512Liu YH, 1996, J FORENSIC SCI, V41, P1018Koda Y, 1996, AM J HUM GENET, V59, P343Kudo T, 1996, J BIOL CHEM, V271, P9830ROUQUIER S, 1995, J BIOL CHEM, V270, P4632KELLY RJ, 1995, J BIOL CHEM, V270, P4640NISHIHARA S, 1994, J BIOL CHEM, V269, P29271MOLLICONE R, 1994, J BIOL CHEM, V269, P20987

Association of maternal mental health and drinking/smoking with adolescents’ mental health based on the Korea National Health and Nutrition Examination Survey

IntroductionDepression is one of the major concerns in adolescence, with a global prevalence of approximately 5%. Diverse environmental factors can affect the development of depression depending on the individual developmental stage.MethodsUsing data from the Korea National Health and Nutrition Examination Survey (KNHANES), we aimed to investigate the association between socioeconomic factors and mental health in a population of non-clinically ill adolescents in Korea totaling 6,261 adolescents aged 12–18 years.ResultsDrinking, smoking, stress, depressed mood, suicidal ideation in adolescents, and stress, depressed mood, and suicidal ideation in mothers were identified as factors associated with adolescent depression. In addition to depressed mood and suicidal ideation, the higher perception of stress in mothers was related to higher stress perception, depressed mood, and suicidal ideation in adolescents. The association of adolescents’ mental health with fathers’ mental health was weaker than that with mothers’ mental health. Additionally, increased smoking and drinking were commonly reported in adolescents with higher stress perception, depressed mood, and suicidal ideation.DiscussionWe conclude that close monitoring of mental health is required for adolescents with drinking and smoking habits and mothers with mental health problems

Real-Time PCR Method for HPV DNA Detection

Human papillomavirus (HPV) infection is an important etiologic factor in cervical carcinogenesis. Various HPV DNA detection methods have been evaluated for clinicopathological level. For the specimens with normal cytological finding, discrepancies among the detection methods were frequently found and adequate interpretation can be difficult. 6,322 clinical specimens were submitted and evaluated for real-time PCR and Hybrid Capture 2 (HC2). 573 positive or &quot;Not Detected but Amplified&quot; (NDBA) specimens by real-time PCR were additionally tested using genetic analyzer. For the reliability of real-time PCR, 325 retests were performed. Optimal cut-off cycle threshold ( ) value was evaluated also. 78.7% of submitted specimens showed normal or nonspecific cytological finding. The distributions of HPV types by real-time PCR were not different between positive and NDBA cases. For positive cases by fragment analysis, concordance rates with real-time PCR and HC2 were 94.2% and 84.2%. In NDBA cases, fragment analysis and real-time PCR showed identical results in 77.0% and HC2 revealed 27.6% of concordance with fragment analysis. Optimal cut-off value was different for HPV types. NDBA results in real-time PCR should be regarded as equivocal, not negative. The adjustment of cut-off value for HPV types will be helpful for the appropriate result interpretation

Standardization of Terminology in Laboratory Medicine II

Standardization of medical terminology is essential in data transmission between health care institutes and in maximizing the benefits of information technology. The purpose of this study was to standardize medical terms for laboratory observations. During the second year of the study, a standard database of concept names for laboratory terms that covered those used in tertiary health care institutes and reference laboratories was developed. The laboratory terms in the Logical Observation Identifier Names and Codes (LOINC) database were adopted and matched with the electronic data interchange (EDI) codes in Korea. A public hearing and a workshop for clinical pathologists were held to collect the opinions of experts. The Korean standard laboratory terminology database containing six axial concept names, components, property, time aspect, system (specimen), scale type, and method type, was established for 29,340 test observations. Short names and mapping tables for EDI codes and UMLS were added. Synonym tables were prepared to help match concept names to common terms used in the fields. We herein described the Korean standard laboratory terminology database for test names, result description terms, and result units encompassing most of the laboratory tests in Korea

Usefulness of Multiplex Real-Time PCR for Simultaneous Pathogen Detection and Resistance Profiling of Staphylococcal Bacteremia

Staphylococci are the leading cause of nosocomial blood stream infections. Fast and accurate identification of staphylococci and confirmation of their methicillin resistance are crucial for immediate treatment with effective antibiotics. A multiplex real-time PCR assay that targets mecA, femA specific for S. aureus, femA specific for S. epidermidis, 16S rRNA for universal bacteria, and 16S rRNA specific for staphylococci was developed and evaluated with 290 clinical blood culture samples containing Grampositive cocci in clusters (GPCC). For the 262 blood cultures identified to the species level with the MicroScan WalkAway system (Siemens Healthcare Diagnostics, USA), the direct real-time PCR assay of positive blood cultures showed very good agreement for the categorization of staphylococci into methicillin-resistant S. aureus (MRSA), methicillin-susceptible S. aureus (MSSA), methicillin-resistant S. epidermidis (MRSE), methicillin-susceptible S. epidermidis (MSSE), methicillin-resistant non-S. epidermidis CoNS (MRCoNS), and methicillin-susceptible non-S. epidermidis CoNS (MSCoNS) ( = 0.9313). The direct multiplex real-time PCR assay of positive blood cultures containing GPCC can provide essential information at the critical point of infection with a turnaround time of no more than 4 h. Further studies should evaluate the clinical outcome of using this rapid real-time PCR assay in glycopeptide antibiotic therapy in clinical settings

MYC quantitation in cell-free plasma DNA by real-time PCR for gastric cancer diagnosis

Background: Detection of tumor-associated genetic alterations in plasma of cancer patients has recently been suggested to be an accurate method for detecting early or recurrent cancer. Methods: We performed quantitative real-time PCR for MYC and GAPDH in tissue and plasma samples of 57 patients with gastric cancer and in plasma of 79 cancer-free individuals. We also performed two-color MYC fluorescence in situ hybridization (FISH) in tissue from the 57 patients with gastric cancer. Results: The tissue MYC/GAPDH ratio by real-time PCR was significantly correlated with MYC status by FISH (p<0.001). The mean ratio of plasma MYC/GAPDH was 5.226+/-3.578 (range: 1.25-18.35) in gastric cancer patients, and 2.436+/-0.881 (range: 1.00-5.00) in the healthy volunteers (p<0.001). We used receiver-operating characteristics (ROC) curve analysis to select two optimal plasma MYC/GAPDH cut-offs of 2.725 and 5.225. The sensitivity and specificity were 75.4% and 76.9% at 2.725, 38.6% and 100% at 5.225, respectively. The plasma MYC/GAPDH ratio from cancer patients was significantly correlated with the tissue MYC/GAPDH ratio (p=0.009), and tissue MYC status by FISH (p=0.024). Conclusions: These findings suggest that the plasma MYC/GAPDH ratio, as determined by real-time PCR, may be an alternative non-invasive approach for detecting gastric cancer. Clin Chem Lab Med 2009; 47:530-6.Kim MA, 2007, HUM PATHOL, V38, P1386, DOI 10.1016/j.humpath.2007.02.005Sai S, 2007, ANTICANCER RES, V27, P2747Mitsui F, 2007, MODERN PATHOL, V20, P622, DOI 10.1038/modpathol.3800777Vita M, 2006, SEMIN CANCER BIOL, V16, P318, DOI 10.1016/j.semcancer.2006.07.015Corzo C, 2006, CANCER GENET CYTOGEN, V165, P151, DOI 10.1016/j.cancergencyto.2005.08.013Crew KD, 2006, WORLD J GASTROENTERO, V12, P354Calcagno DQ, 2005, ANTICANCER RES, V25, P4069Gotoh T, 2005, J CLIN ONCOL, V23, P5205, DOI 10.1200/JCO.2005.02.014Tse C, 2005, CLIN CHEM, V51, P1093, DOI 10.1373/clinchem.2004.044305Kindich R, 2005, CLIN CHEM, V51, P649, DOI 10.1373/clinchem.2004.045013Lee TL, 2002, CLIN CANCER RES, V8, P1761Usadel H, 2002, CANCER RES, V62, P371*AM JOINT COMM CAN, 2002, AJCC CANC STAG MAN, P99Livak KJ, 2001, METHODS, V25, P402, DOI 10.1006/meth.2001.1262Lee HS, 2001, CANCER, V92, P1427Lo YMD, 2001, CLIN CANCER RES, V7, P1856Koo SH, 2000, CANCER GENET CYTOGEN, V117, P97AALTONEN LA, 2000, INT AGENCY RES CANC, P37Castells A, 1999, J CLIN ONCOL, V17, P578Hara T, 1998, LAB INVEST, V78, P1143Landis SH, 1998, CA-CANCER J CLIN, V48, P6Suzuki S, 1997, J SURG ONCOL, V66, P173Nawroz H, 1996, NAT MED, V2, P1035Henriksson M, 1996, ADV CANCER RES, V68, P109PARK JG, 1990, CANCER RES, V50, P2773STROUN M, 1989, ONCOLOGY, V46, P318LAUREN P, 1965, ACTA PATHOL MIC SC, V64, P31