AIMTo determine phenytoin sodium by a highly accurate nephelometric titration.

METHODSThe titration operating conditions were optimized and the solubility product constant of phenytoin silver precipitation was determined.

RESULTSThe result of the titration is comparable to those of control experiments.

CONCLUSIONThe proposed method has been found to be accurate, precise, specific, reproducible, and linear.

Dual-magnetic circuit beads and scattering nephelometry dual channel semiautomatic coagulometers are used for the coagulational evaluation of the 5 blood contact medical devices which consist of metals and polymers. The partial thromboplastin time(PTT) and prothrombin time(PT) tests are made based on the GB/T 16886.4-2003 standard. The results indicate that the coefficient of variation in the two groups is in the identical order of magnitude. In the PTT tests, they give the similar evaluational results. With the smaller numerical values of the PT tests, the different coagulometers give the high consilience results. So, both of dual-magnetic circuit beads and scattering nephelometry coagulometers are acceptable in the medical devices' coagulational evaluations. But the interpretation and analysis of the results of the small numerical value tests, PT tests for example, should be noticed.
Blood Coagulation Tests ; instrumentation ; methods ; Magnetics ; instrumentation ; Nephelometry and Turbidimetry ; instrumentation

PURPOSE: In recent years, cystatin C (CysC) was proposed as a new marker for evaluating the glomerular filtration rate due to a constant serum level. The aim of this study was to measure serum CysC values of healthy young Korean men in assessment of kidney function and compare it with other reports until now in male populations, using nephelometric immunoassay. METHODS: CysC and creatinine levels were measured by particle enhanced nephelometric immunoassay and Jaffe method, respectively, in 145 young Korean men without evidence of kidney disease. Medline was searched for CysC reference values in healthy male populations. RESULTS: CysC values showed a normal distribution (Kolmogorov-Smirnov, K-S, p=0.2). The CysC reference interval for healthy young Korean men (age 19-29) was 0.58 to 0.94 mg/L (0.76+/-0.09 mg/ L, X+/-2SD, range 0.60 to 1.25 mg/L). Reference intervals for creatinine was 0.79 to 1.27 mg/dL (1.03+/-0.12 mg/dL, X+/-2SD, range 0.8 to 1.3 mg/dL) in subjects. Creatinine serum values did not show a normal distribution (K-S, p=0.001). The correlation coefficient for CysC and creatinine was only 0.308. (p=0.0001) Nephelometric CysC reference intervals we determined were consistent among different male populations. CONCLUSION: We determined reference intervals for CysC values in healthy young Korean men, and CysC reference values established by nephelometric immunoassay were consistent among different men population. This information could be useful in assessing renal function in healthy young Korean men.
Creatinine ; Cystatin C ; Glomerular Filtration Rate ; Humans ; Immunoassay ; Kidney ; Kidney Diseases ; Male ; Nephelometry and Turbidimetry ; Reference Values

BACKGROUND: Neutrophil gelatinase-associated lipocalin (NGAL) is known to be one of the ideal biomarkers for acute kidney injury providing early information on damage to the kidney. METHODS: We evaluated the performance for precision and the reportable range of the automated NGAL Test (Bioporto Diagnostics, Denmark) assay and compared the values of these tests with widely used point of care test. The reference interval of NGAL was established in Korean adults. RESULTS: Within run percent coefficient of variation (%CV) and total precision %CV for 2 levels were all within 5%. The reportable range was found to be acceptable for the range of 57.0 - 3182.0 ng/mL (r=0.999). The method comparison was made between Biosite's assay and Bioporto Diagnostics' (Passing and Bablok fit, y=1.94x - 5.29; x, Biosite; y, Bioporto; n=31; y range, 250 to 1,308 ng/mL; r2=0.959). The correlation was linear within the limit of 1,500 ng/mL, but not beyond this limit. The 2.5 and 97.5 percentile of the reference range for the samples were 43.2 ng/mL and 124.8 ng/mL, respectively. CONCLUSIONS: Since NGAL Test can be used in automated chemical analyzer, it can not only reduce the man power and time consumed in but also displayed excellent precision and linearity.
Acute Kidney Injury ; Biomarkers ; Chemistry, Clinical ; Immunoassay ; Lipocalins ; Nephelometry and Turbidimetry ; Neutrophils ; Reference Values

Serum Immunoglobulin (Ig)A, IgG, IgM, levels were measured in 99 coal workers' pneumoconiosis (CWP) patients and 12 healthy coal workers and 9 non-miners to compare with each group by the radiological categories, its complications and working period in coal mine. Serum were measured by nephelometry. The findings were as follows: 1) Serum IgA levels were significantly different between three groups of CWP patient, healthy coal worker and non-miner (mean+/-standard deviation: 226.4+/-87.7, 221.3+/-45.1, 170.1+/-65.7 respectively). 2) There were no significant differences of Ig levels among radiological categories of CWP. 3) There were no significant differences of Ig levels among simple pneumoconiosis and its complicated disorders. 4) The three Ig levels were slightly increased in the group of mining years less than 20 years (IgA: r=0.1869, p<0.10 IgG: r=0.2902, p<0.05 IgM: r=0.2889, p<0.05).
Coal* ; Humans ; Immunoglobulin A ; Immunoglobulin G ; Immunoglobulin M ; Immunoglobulins* ; Mining ; Nephelometry and Turbidimetry ; Pneumoconiosis*

BACKGROUND AND OBJECTIVES: Immunoglobulin G (IgG) subclass deficiency has been reported in patients with bronchial asthma and is associated with recurrent respiratory tract infections. Aspirin-sensitive asthma (ASA) which affects 10% of adult asthmatics, asthma runs a chronic course with frequent asthma exacerbations, often related to respiratory infections. We performed this study to identify the prevalence of IgG subclass deficiency and evaluate the association between recurrent asthma exacerbations and IgG subclass deficiency in ASA. SUBJECTS AND METHODS: We measured serum levels of IgG and IgG subclass in 26 aspirin- sensitive asthmatic patients (15 steroid used and 11 steroid not used) and 55 healthy controls using nephelometry. Reference values of each IgG subclass was defined as cumulative percentile between 2.5% to 97.5% of controls. RESULTS: Total IgG, IgG1, IgG2 and IgG3 of aspirin-sensitvie asthmatics, were significantly lower than for those of controls (p<0.05, respectively). However, there were no significant differences in total IgG and IgG subclass concentrations, between steroid-not-used asthma group and controls (p>0.05, respectively). CONCLUSION: Lowered levels of IgG, IgG1, IgG2 and IgG3 were noted in ASA sensitive asthma patients, which might be associated with use of steroid. Further studies will be needed to evaluate their clinical significance.
Adult ; Asthma* ; Humans ; Immunoglobulin G* ; Nephelometry and Turbidimetry ; Prevalence ; Reference Values ; Respiratory Tract Infections

PURPOSE: Measurement of antistreptolysin O (ASO) is often necessary to confirm a clinical diagnosis of recent streptococcal infection, especially in patients suspected of rheumatic fever and acute glomerulonephritis. Standard normal ranges for ASO should be established locally for each age group. We analyzed ASO to determine the upper limit of normal (ULN) ASO in children in the Gyeonggi-Incheon area. METHODS: ASO in normal individual concentrations were measured quantitatively by nephelometry on sera from 753 children (Male:381, Female:372). ULN were determined by separating the upper 20% from the lower 80% of the group (80 percentile). RESULTS: The mean ASO concentration calculated in a total cases was 149.9+/-7.2 IU/mL. The ASO concentration in neonates was 83.4+/-10.7 IU/mL, and lowest in the 1 year of age group, 26.7+/-6.6 IU/ mL, and increased to 318.0+/-33.2 IU/mL gradually in the 9 years of age group. Thereafter, ASO concentration decreased. The ULN for neonates was 122 IU/mL, for 0-3 years, 40 IU/mL; for 4-6 years, 113 IU/ mL; for 7-9 years, 489 IU/mL; for 10-19 years, 433 IU/mL; for 20-29 years, 122 IU/mL. CONCLUSION: The age-specific ULN for children in the Gyeonggi-Incheon area were determined. The distribution of ASO concentration according to age groups was different from previous reports. These results should be of clinical value to physicians to interprete the ASO results of their patients.
Antistreptolysin* ; Child* ; Diagnosis ; Glomerulonephritis ; Humans ; Infant, Newborn ; Nephelometry and Turbidimetry ; Pediatrics ; Reference Values ; Rheumatic Fever ; Streptococcal Infections

OBJECTIVE: Rheumatoid factor (RF) is used as one of the criteria for the diagnosis of rheumatoid arthritis (RA). Nephelometers are widely used in laboratories to quantitatively measure RF. In nephelometric ways of measurement, there are endpoint nephelometry and rate nephelometry. BN II System (BN II) (Dade Behring Marburg GmbH, USA) is a well known endpoint nephelometer while IMMAGE System (IMMAGE) (Beckman Coulter, USA) is a well known rate nephelometer. We compared these two automatic nephelometric analyzers to evaluate which method shows the best results. METHODS: We measured RF (n=195) using the two machines. We evaluated the correlation between BN II and IMMAGE. We compared the results of BN II with those of IMMAGE in terms of interference and clinical usefulness. RESULTS: The correlation coefficient (r) of RF was 0.9310 (p<0.0001). We could not find any significant interference for BN II with high concentration of triglyceride or bilirubin, but IMMAGE showed significant interferences with high concentrations of triglyceride and bilirubin. The sensitivity and specificity of BN II for the diagnosis of RA were 90.3% and 82.4%. Those of IMMAGE were 86.1% and 74.5%. CONCLUSION: BN II was enough to satisfy the analytical features and it showed better results than IMMAGE. We expect BN II, the endpoint nephelometer, to be the best equipment in measuring RF for diagnosis of RA.
Arthritis, Rheumatoid ; Bilirubin ; Diagnosis ; Nephelometry and Turbidimetry ; Rheumatoid Factor* ; Sensitivity and Specificity ; Triglycerides

Although throat culture is a gold standard to diagnose group A streptococcal (GAS) pharyngitis or its sequelae, antistreptolysin O (ASO) is useful to confirm the diagnosis. In case there is no elevation of ASO, it is necessary to add one or more serologic tests, such as antideoxyribonuclease (ADNase) B test. ADNase B levels were analyzed in the carriers of beta-hemolytic streptococci (BHS) in this study. ADNase B concentrations were determined quantitatively by nephelometry (Behring Nephelometer 100 Analyzer, Germany) on 157 sera of healthy elementary school children in Chungnam who were positive of BHS in the throat culture. ASO levels were measured previously by autoanalyzer (Hitachi 747, Japan). Mean ADNase B and ASO levels were compared according to serological group of BHS and number of colonies. The carriers of GAS had significantly higher ADNase B levels (mean 453 IU/ml) than those of non-A beta-hemolytic streptococci (NGAS, 278 IU/ml), while the difference of ASO levels between GAS (482 IU/ml) and NGAS (350 IU/ml) carriers was not so high. The carriers who had more than 10 CFU of BHS had significantly higher ADNase B or ASO levels than those who had less than 10 CFU. The correlation between ADNase B (Y) and ASO (X) was Y=0.4X+229 (r2=0.13). ADNase B test could discriminate GAS from NGAS more effectively than ASO test. The carriers who have more than 10 CFU might undergo asymptomatic infection, as their ADNase B or ASO levels were significantly high. Because distribution of ADNase B showed little correlation to that of ASO, ADNase B test could be used as a supplementary test to diagnose GAS infection.
Antistreptolysin ; Asymptomatic Infections ; Child ; Chungcheongnam-do ; Diagnosis ; Humans ; Nephelometry and Turbidimetry ; Pharyngitis ; Pharynx ; Serologic Tests

The followings are the results for external quality assessment (EQA) in immunoserology for 2004: 1. Evaluation of EQA was done in 2 trials in May and November, about 99% of laboratories participating average 8.4 items. EQA for anti-HBc test was newly started in 2004. 2. Commercial control, MASR Immunology Control from Medical Analysis Systems (Camarillo, CA, USA) was used to assure the quality of quantitative results of C-reactive protein (CRP), rheumatoid factor (RF) and anti-streptolysin O (ASO) tests in 2004. All the specimens for Immunoserology in EQA were delivered refrigerated for the first time, being received within 48 hours after sending. 3. EQA for detection of HBsAg mutants was tried for the first time, using the recombinant HBsAg mutant (Gly/Arg 145) kindly provided by Abbott Laboratories, USA. 4. The laboratories using immunochromatography assay (ICA) were increased, however, many laboratories using ICA reported falsely negative for the positive specimens. The sensitivity of ICA test kits as well as various factors influencing the ICA results should be evaluated. 5. Standardization of methods including calibrators for quantitative results should be required for the harmonization of results.
Allergy and Immunology ; C-Reactive Protein ; Hepatitis B Surface Antigens ; Immunochromatography ; Korea* ; Nephelometry and Turbidimetry ; Rheumatoid Factor