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.

Nephelometry and Turbidimetry ; methods ; Phenytoin ; analysis ; Reproducibility of Results ; Solutions ; Titrimetry ; methods

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

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

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

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

BACKGROUND AND OBJECTIVE: IgG subclass deficiency has been reported in patients with bronchial asthma and is associated with recurrent respiratory tract infections. This study was done to identify prevalence of IgG subclass deficiency and to evaluate the possible difference between atopic and non-atopic asthmatics. Subjects and METHODS: We measured serum levels of IgG and IgG subclass in 35 asthmatic patients and 50 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 and IgG2 of asthmatics were significantly lower than for those of controls(p<0.05, respectively). In atopic asthmatics, compared with non-atopic asthmatics, IgG4 level was significantly higher (p<0.05). The frequency of IgG subclass levels below the reference value was eight (22.9%) of 35 asthmatics. CONCLUSION: IgG, IgG1 and IgG2 were significantly lower in asthmatic patients. Some patients had IgG subclass levels below reference value. Further studies will be needed to evaluate their clinical significance.
Asthma* ; Humans ; Immunoglobulin G* ; Nephelometry and Turbidimetry ; Prevalence ; Reference Values ; Respiratory Tract Infections

BACKGROUND: The serologic tests for syphilis infection have been performed manually, but the procedures are time-consuming and interpretations may be subjective. Recently, automated assays were developed for rapid and efficient testing for syphilis infection. In this study, we evaluated the performances of IMMUNOTICLES Auto3 RPR and Auto3TP (A&T Corporation, Japan) using latex agglutination turbidimetry method. METHODS: Using 236 serum samples referred for syphilis at Ewha Womans University, Mokdong Hospital, between March 2004 and April 2007, we evaluated precision, linearity, detection limit and compared with the results of manual serologic tests, RPR (RPR card test, ASAN Pharmaceutical, Korea) and TPHA (ASAN-TPHA, ASAN Pharmaceutical). RESULTS: The within-run and between day precisions of Auto3RPR and Auto3TP were from 2.1% to 4.8%. The linearity was good up to 5.0 RU for Auto3RPR and to 250 TU for Auto3TP. Agreement of Auto3RPR with RPR was 65.7% (155/236) and 32.6% of patients (77/236) were RPR positive and Auto3RPR negative. RPR titers were less than 1:8 in 99% of these discrepant samples (76/77) and 65% (50/77) were latent infection and the others were false positive (32%, 27/77). Agreement of Auto3TP with TPHA was 97.1%. CONCLUSIONS: IMMUNOTICLES Auto3RPR and Auto3TP may be useful for rapid and efficient testing for syphilis. However, discrepant results were present in patients with low titer RPR positivity and method of reporting shoud be considered in individual clinical situation. In addition, linear range was not wide and further study is needed for reporting of quantitative results.
Agglutination ; Automation ; Chungcheongnam-do ; Female ; Humans ; Latex ; Limit of Detection ; Nephelometry and Turbidimetry ; Serologic Tests ; Syphilis*

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

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

OBJECTIVETo determine bacterial endotoxin in the replacement solution of on-line hemodiafiltration (on-line HDF) using kinetic turbidimetric limulus test.

METHODS AND RESULTSValidation test was performed with the replacement solution of on-line HDF in which quantified standard endotoxin was added. The recovery rates of endotoxin from the replacement solution and its dilutions at 1/5, 1/10, and 1/20 were 58.17%, 106.7%, 99.00% and 98.79%, respectively, suggesting that the optimal dilution was at 1/10. Standard endotoxin was added into the replacement solution of on-line HDF of 3 batches (040408, 040511,040527), and the recovery rates in their dilution at 1/10 were 76.32%, 99.00% and 96.24%, respectively. The standard endotoxin in the working curve was 1.00, 0.125, and 0.0156 Eu/ml (endotoxin unit/ml), and the dilution at 1/10 of the replacement solution is effective to eliminate the interference in limulus test.

CONCLUSIONKinetic turbidimetric limulus test provide a means to detect endotoxin in the replacement solution of on-line HDF.

Endotoxins ; analysis ; Hemodiafiltration ; methods ; Hemodialysis Solutions ; analysis ; Humans ; Kinetics ; Limulus Test ; Nephelometry and Turbidimetry ; methods