BACKGROUND: Red blood cell (RBC) sorbitol has been implicated in the pathogenesis of organic complications of diabetes mellitus. W8 investigated RBC sorbitol level as an indicator of glucose control or diabetic complications, and also evaluated whether RBC sorbitol/plasma glucose ratio is an indicator of diabetic complications. METHODS: RBC sorbitol levels were measured in 43 healthy persons and 133 diabetes mellitus (DM) patients by enzymatic method. We also tested linearity, inter- and intra- assay precisions. Plasma glucose and Hb Alc were measured by hexokinase method and HPLC, respectively. Hospital records were reviewed. RESULTS: The intra- and inter-assay coefficients of variation of RBC sorbitol test are 8.7% and 28.5%, respectively. Linearity is good. The RBC sorbitol level(3.60+/-1.00 ug/mL) and RBC sorbitol/plasma glucose ratio (2.37+/-0.98%) in diabetic patients are significantly higher than those in normal control (1.69+/-0.43 ug/mL, 1.85+/-0.49 per mill), respectively(p<0.0001). We can't observe correlation between RBC sorbitol and Hb Alc in BM patients, but observe that in non-treatment DM patients. We also observed correlation between Hb Alc and glucose and reverse correlation between RBC sorbitol ratio and Hb Alc. We can't find significant relation between diabetic complications and RBC sorbitol or RBC sorbitol/plasma glucose. CONCLUSIONS: We suggest that the reference range of normal RBC sorbitol level and RBC sorbitol/plasma glucose ratio by enzymatic method are 1.69+/-0.86 ug/mL and 1.85+/- 0.98%,. These Ire significantly different from DM patients and may be useful in diagnosis of DM.
Blood Glucose ; Chromatography, High Pressure Liquid ; Diabetes Complications ; Diabetes Mellitus* ; Diagnosis ; Erythrocytes ; Glucose ; Hexokinase ; Hospital Records ; Humans ; Reference Values ; Sorbitol*

BACKGROUND: Red blood cell (RBC) sorbitol has been implicated in the pathogenesis of organic complications of diabetes mellitus. W8 investigated RBC sorbitol level as an indicator of glucose control or diabetic complications, and also evaluated whether RBC sorbitol/plasma glucose ratio is an indicator of diabetic complications. METHODS: RBC sorbitol levels were measured in 43 healthy persons and 133 diabetes mellitus (DM) patients by enzymatic method. We also tested linearity, inter- and intra- assay precisions. Plasma glucose and Hb Alc were measured by hexokinase method and HPLC, respectively. Hospital records were reviewed. RESULTS: The intra- and inter-assay coefficients of variation of RBC sorbitol test are 8.7% and 28.5%, respectively. Linearity is good. The RBC sorbitol level(3.60+/-1.00 ug/mL) and RBC sorbitol/plasma glucose ratio (2.37+/-0.98%) in diabetic patients are significantly higher than those in normal control (1.69+/-0.43 ug/mL, 1.85+/-0.49 per mill), respectively(p<0.0001). We can't observe correlation between RBC sorbitol and Hb Alc in BM patients, but observe that in non-treatment DM patients. We also observed correlation between Hb Alc and glucose and reverse correlation between RBC sorbitol ratio and Hb Alc. We can't find significant relation between diabetic complications and RBC sorbitol or RBC sorbitol/plasma glucose. CONCLUSIONS: We suggest that the reference range of normal RBC sorbitol level and RBC sorbitol/plasma glucose ratio by enzymatic method are 1.69+/-0.86 ug/mL and 1.85+/- 0.98%,. These Ire significantly different from DM patients and may be useful in diagnosis of DM.
Blood Glucose ; Chromatography, High Pressure Liquid ; Diabetes Complications ; Diabetes Mellitus* ; Diagnosis ; Erythrocytes ; Glucose ; Hexokinase ; Hospital Records ; Humans ; Reference Values ; Sorbitol*

The high level of low density lipoprotein (LDL) is a risk factor for cardiovascular disease. Apolipoprotein (apo) B is a major protein component of LDL and plays an important role in the maintenance of cholesterol homeostasis. In this study, six polymorphic sites of the apoB gene were anlaysed in 235 patients with coronary artery disease (CAD) and 216 normal control subjects. There were no significant differences in the allele frequencies of apoB polymorphisms between the control and patient groups. However, haplotype frequencies were significantly different between the CAD patients and control (p<0.05). In addition, the allelic distributions of both EcoRI and MspI polymorphisms in Koreans were similar to those in Chinese but significantly different from those in Caucasians. ApoB polymorphisms showed no association with plasma lipid levels. In conclusion, haplotype analysis of the apoB gene using multiple diallelic markers might be a useful marker for Korean CAD patients.
Adult ; Apolipoproteins B/*genetics ; Coronary Arteriosclerosis/*genetics ; Female ; Gene Frequency ; Genetic Markers ; Haplotypes ; Human ; Korea ; Male ; Middle Age ; Polymorphism (Genetics) ; Variation (Genetics)

No abstract available.
Internet ; *Publishing ; Search Engine

Among ~20 RBC enzyme deficiencies causing hereditary hemolytic anemia (HRA), deficiencies involving three RBC enzymes such as glucose-6-phosphatase, pyruvate kinase and pyrimidine 5'-nucleodiase were known to be relatively common. The methods that have been used for RBC enzyme analysis are based on the kinetic spectrophotometry. This method, however, usually requires multiple step reactions and manual manipulations which are labor-intensive and time-consuming, and carry a greater risk of error due to their complexity. To solve this problem, we had successfully developed the multiplex enzyme analysis for galactose using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). We are now trying to adopt this method to other RBC enzymes associated with HRA. The devised method will allow simple, rapid, sensitive and reproducible quantification of RBC enzymes and should be helpful for the confirmatory diagnosis of HRA caused by RBC enzyme deficiencies.
Anemia, Hemolytic, Congenital ; Galactose ; Glucose-6-Phosphatase ; Mass Spectrometry ; Pyrimidines ; Pyruvate Kinase ; Spectrophotometry

BACKGROUND: The amino-terminal pro-brain natriuretic peptide (NT-proBNP) is a useful biomarker for the diagnosis of acute congestive heart failure. A point-of-care test (POCT) could rapidly detect the presence of NT-proBNP during emergencies. We evaluated the analytical performance of the new Samsung LABGEO PA CHF Test (Samsung Electronics, Korea). METHODS: Based on the guidelines of the Clinical and Laboratory Standards Institute (CLSI), we compared the precision, linearity, and method with those of the E170 (Roche Diagnostics, Switzerland). Matrix comparison between the NT-proBNP values in whole blood and plasma was also performed, and the reference interval was determined using residual samples from healthy adults selected based on the evaluation criteria. RESULTS: The Samsung LABGEO PA CHF Test provided results in approximately 18 min. The coefficient of variation (CV) of within-laboratory precision was below 6.8%. A desirable linearity was observed in the range of 0–10,000 pg/mL, with R²=0.99. The correlation with E170 was also excellent (N=108, r=0.96). NT-proBNP values in the whole blood were correlated with those in the plasma (N=36, r=0.99). The reference interval for the circulating NT-proBNP concentration was determined in 118 plasma samples from healthy subjects (26-75 yr of age). The 97.5th percentile was found to be 58.3 pg/mL. CONCLUSIONS: The Samsung LABGEO PA CHF Test demonstrated a good analytical performance. It could be a powerful tool as a POCT for clinical practice, particularly during emergencies.
Adult ; Diagnosis ; Emergencies ; Healthy Volunteers ; Heart Failure ; Humans ; Methods ; Plasma ; Point-of-Care Systems* ; Point-of-Care Testing

BACKGROUND: Vitamin D has been recently shown to play important roles in the functioning of various systems. Most of the current analytical methods for measuring vitamin D levels are based on immunoassays. We simultaneously measured the levels of 25-hydroxyvitamin D3 [ 25(OH)D3 ] and 25-hydroxyvitamin D2 [ 25(OH)D2 ] in human serum by performing ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) after Diels-Alder derivatization with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) and evaluated the performance of our method. METHODS: After liquid-liquid extraction, samples were dried under N2 at 50degrees C for 1 hr followed by Diels-Alder derivatization with ethyl acetate containing 0.1 mg/mL PTAD. The samples were resuspended in 60 microL of methanol:10 mM ammonium formate solution (1:1, V/V). C18 UPLC column and positive ion multiple reaction monitoring transitions such as m/z 558.35-->298.1, 25(OH)D3; m/z 570.35-->298.1, 25(OH)D2; and m/z 564.35-->298.1, hexadeuterated-25(OH)D3 were used for UPLC-MS/MS. RESULTS: The within-run imprecision (CVs) for 25(OH)D3 and 25(OH)D2 were 3.5-4.0% and 3.8-4.2%, respectively, and the corresponding between-run CVs were 3.3-5.5% and 4.7-5.8%. The lower limit of quantification for 25(OH)D3 and 25(OH)D2 were 0.5 and 1.0 ng/mL, respectively. The curve for interassay calibration variability data obtained over concentrations of 0-120 ng/mL for 25(OH)D3 and 0-90 ng/mL for 25(OH)D2 was linear and reproducible [ 25(OH)D3, R2=0.993; 25(OH)D2, R2=0.998]. The total 25(OH)D levels in Koreans (average, 18.7 ng/mL) were lower than those in American Caucasians, and the percentage of people with total 25(OH)D levels under 10 ng/mL was 8.1%. CONCLUSIONS: Our method to measure 25(OH)D3 and 25(OH)D2 levels by performing UPLC-MS/MS after PTAD derivatization showed good performance as a sensitive and reproducible method for routine analysis of vitamin D status.
25-Hydroxyvitamin D 2 ; Acetates ; Calcifediol ; Calibration ; Formates ; Humans ; Immunoassay ; Liquid-Liquid Extraction ; Mass Spectrometry ; Quaternary Ammonium Compounds ; Tandem Mass Spectrometry ; Triazoles ; Vitamin D

BACKGROUND: The hemoglobin A1c (HbA1c) level is widely used to diagnose and monitor glycaemic control in people with diabetes mellitus, and various methods are used for its determination. The D-100 hemoglobin testing system (Bio-Rad Laboratories, USA) is a fully automated, high-throughput glycohaemoglobin analyzer based on an ion-exchange high-performance liquid chromatographic method. Here, we evaluated the analytical performance of a newly developed HbA1c analyzer. METHODS: Precision, linearity, and comparison to the Variant II Turbo analyzer (Bio-Rad Laboratories, USA) were evaluated according to the Clinical Laboratory Standards Institute guidelines. Carryover, bias from the value assigned by the HbA1c Network Laboratory of Korea Centers for Disease Control and Prevention, and the vulnerability to interference by hemoglobin variants frequently found in Korea were also assessed. Statistical analyses were performed using Excel 2010 (Microsoft Co., USA) and MedCalc ver. 14.12.0 (MedCalc Software bvba, Belgium). RESULTS: The coefficients of variation for repeatability and within-device precision were less than 1.08% in National Glycohaemoglobin Standardization Program (NGSP) unit and less than 1.68% in international system of unit at all three levels. The calibration curve was linear, with R²=0.996 in the range of 4.6% to 15.4% in NGSP unit. The results highly correlated with those produced by Variant II Turbo (r=0.998). The 95% confidence interval for differences from the assigned values was -3.3% to 2.9%. No significant interferences of haemoglobin variants were observed except for Hemoglobin Yamagata. CONCLUSIONS: The D-100 hemoglobin testing system showed excellent precision, linearity, and good correlation with the Variant II Turbo analyzer and agreement with the assigned values. Therefore, its analytical performance is satisfactory for diabetes diagnosis and treatment monitoring.
Bias (Epidemiology) ; Calibration ; Centers for Disease Control and Prevention (U.S.) ; Diabetes Mellitus ; Diagnosis ; Hemoglobin A, Glycosylated ; Korea ; Methods

BACKGROUND: We evaluated the performance of multiplex tandem mass spectrometry (MS/MS) in newborn screening for detection of 6 lysosomal storage disorders (LSDs), namely, Niemann-Pick A/B, Krabbe, Gaucher, Fabry, and Pompe diseases and Hurler syndrome. METHODS: We revised the conditions and procedures of multiplex enzyme assay for the MS/MS analysis and determined the precision of our enzyme assay and the effects of sample amounts and incubation time on the results. We also measured the degree of correlation between the enzyme activities in the dried blood spots (DBSs) and those in the leukocytes. DBSs of 211 normal newborns and 13 newborns with various LSDs were analyzed using our revised methods. RESULTS: The intra- and inter-assay precisions were 2.9-18.7% and 8.1-18.1%, respectively. The amount of product obtained was proportional to the DBS eluate volume, but a slight flattening was observed in the product vs. sample volume curve at higher sample volumes. For each enzyme assay, the amount of product obtained increased linearly with the incubation period (range, 0-24 hr). Passing and Bablok regression analysis revealed that the enzyme activities in the DBSs and those in the leukocytes were favorably correlated. The enzyme activities measured in the DBSs were consistently lower in patients with LSDs than in normal newborns. CONCLUSIONS: The performance of our revised techniques for MS/MS detection and enzyme assays was of the generally acceptable standard. To our knowledge, this is the first report on the use of MS/MS for newborn screening of LSDs in an Asian population.
Dried Blood Spot Testing ; Enzyme Assays ; Enzymes/blood ; Humans ; Infant, Newborn ; Leukocytes/enzymology ; Lysosomal Storage Diseases/*diagnosis ; Republic of Korea ; Tandem Mass Spectrometry/*methods ; Time Factors