scholarly journals Standards versus Standardised Methods in Enzyme Assay

1983 ◽  
Vol 20 (1) ◽  
pp. 52-59 ◽  
Author(s):  
R T P Jansen ◽  
A P Jansen
Keyword(s):  
Quality Control ◽  
Alkaline Phosphatase ◽  
Creatine Kinase ◽  
Lactate Dehydrogenase ◽  
Alanine Aminotransferase ◽  
Enzyme Assay ◽  
Control Program ◽  
Internal Quality ◽  
Quality Control Program ◽  
Control Serum

In a trial of the Netherlands coupled external/internal quality control program a control serum and an enzyme standard were analysed over a period of eight weeks, five times each week. Five enzymes were determined: alkaline phosphatase, creatine kinase, lactate dehydrogenase, alanine aminotransferase, and γ-glutamyltransferase. The measured values in the serum were converted to the standards. Those laboratories using the recommended methods also submitted their non-transformed serum values. The following standardisation techniques have been compared: ( a) no standardisation of methodology but use of enzyme standards; ( b) standardisation of methodology; ( c) standardisation of methodology combined with use of an enzyme standard. Results were submitted to analysis of variance. Standardisation of methodology did not yield smaller interlaboratory variation than the standardisation with enzyme standards. In this trial a combination of both standardisation techniques yielded generally better results. Results for γ-glutamyltransferase indicate that standardisation of substrate may be necessary apart from the use of an enzyme standard. The preparation of stable enzyme standards is stressed.

scholarly journals Blood Biomarkers of Recovery Efficiency in Soccer Players

2019 ◽  
Vol 16 (18) ◽  
pp. 3279 ◽  
Author(s):  
Anna Nowakowska ◽  
Dorota Kostrzewa-Nowak ◽  
Rafał Buryta ◽  
Robert Nowak
Keyword(s):  
Alkaline Phosphatase ◽  
Creatine Kinase ◽  
Lactate Dehydrogenase ◽  
Alanine Aminotransferase ◽  
Soccer Players ◽  
Control Group ◽  
Iron Level ◽  
Recovery Efficiency ◽  
Lactate Dehydrogenase Activity ◽  
Over Time

Physical exercise strongly affects human metabolism and causes biochemical changes. This study aimed to investigate the relationship between routine plasma biomarker levels and recovery efficiency in soccer players during an entire competitive match season. The players participating in the study were divided into a midfielder/defender group (seven midfielders and seven defenders) and a goalie/substitute group (six persons—goalkeepers and players with a short cumulative match-time). The fasting capillary blood samples were taken 17–24 h after each competitive match. The blood plasma was used to determine the creatinine, urea, alkaline phosphatase, creatine kinase, lactate dehydrogenase, aspartate and alanine aminotransferase, iron and magnesium levels of the athletes. The levels of (AST) (aspartate aminotransferase), (ALT) (alanine aminotransferase) and (Cr) creatinine were higher in the midfielder/defender group than in the control group, but only AST and Cr significantly varied over time (AST decreased, and Cr increased with time). The (LDH) (lactate dehydrogenase) activity and urea level were significantly lower in the midfielder/defender group than in the goalie/substitute group, and it significantly varied over time (LDH decreased, and urea increased with time). No differences in the (CK) creatine kinase and (ALP) alkaline phosphatase activities between the groups was found, although CK increased significantly with time in the midfielder/defender group (particularly midfielders in the spring round). In midfielders, the AST activity and the iron level were significantly lower in the spring than in the autumn round. On the contrary, ALT, CK, urea and magnesium levels were significantly higher in the spring than in autumn round. A long-term measurement of biochemical parameters in elite soccer players indicated that AST, CK, LDH and creatinine levels, when analyzed together, could constitute a useful set of markers for monitoring recovery periods.

scholarly journals Variation in 1(3S) and 2(2S) rejections incidence in internal quality control program on using 20 reading mean and SD of different periods

2016 ◽  
Vol 7 (2) ◽  
pp. 48
Author(s):  
Khushbu Suryaprakash Soni ◽  
Riddhiben Rajendrakumar Patel ◽  
Shailesh Manubhai Patel ◽  
Sarita Jagadishbhai Mangukia
Keyword(s):  
Quality Control ◽  
Control Program ◽  
Internal Quality Control ◽  
Internal Quality ◽  
Quality Control Program

ARIC Hemostasis Study - III. Ouality Control

1993 ◽  
Vol 70 (04) ◽  
pp. 588-594 ◽  
Author(s):  
Lloyd E Chambless ◽  
Robert McMahon ◽  
Andrea Finch ◽  
Paul Sorlie ◽  
Gerardo Heiss ◽  
...  
Keyword(s):  
Quality Control ◽  
Control Program ◽  
Internal Quality Control ◽  
Factor Vii ◽  
Quality Assurance Program ◽  
Internal Quality ◽  
Blood Collection ◽  
Quality Control Program ◽  
Atherosclerosis Risk In Communities ◽  
Field Center

SummaryMethods and results from the quality assurance program of the Atherosclerosis Risk in Communities (ARIC) Study regarding hemostasis variables are presented, following up previous reports in this journal on standardized procedures for blood collection and processing (7) and an organized plan for the performance of those procedures (8). Efforts were made to control for and assess all sources of variability, from venipuncture to laboratory analysis, including also local field center processing and sample shipping. The quality control program included (a) a standardized protocol for blood collection and processing; (b) training, certification, and annual recertification of field center personnel for blood collection and processing; (c) monitoring of fasting times, phlebotomy times, processing times, and shipping problems; (d) hemostatic laboratory internal quality control; (e) a replicate blood sample program; (f) an intraindividual variability study; and (g) continual monitoring of quality control and study participants’ data. This paper focused on items (c), (d), and (e). Measures of Variation, generally Standard deviations and coefficients of Variation, are estimated for replicate blood sampling and internal quality control data, for activated partial thromboplastin time, fibrinogen, factor VII and VIII activity, von Willebrand factor, antithrombin-III, and protein C. The results demonstrate that it is possible to reliably measure these hemostatic variables in a large multicenter study.

scholarly journals Interlaboratory Oral Anticoagulant Quality Assessment by the Netherlands Federation of Thrombosis Services

1977 ◽  
Author(s):  
C.A. van Dijk-Wierda ◽  
J. Hermans ◽  
E.A. Loeliger ◽  
J. Roos
Keyword(s):  
Quality Control ◽  
The Netherlands ◽  
Random Error ◽  
Control Program ◽  
Great Majority ◽  
Internal Quality ◽  
Quality Control Program ◽  
Blood Samples ◽  
Monthly Distribution ◽  
External Program

The 50 laboratories of the Netherlands Federation of Thrombosis Services have participated since 1974 in a voluntary external and internal quality control program. The external program comprises a monthly distribution to the member laboratories of a series of artificially prepared control blood samples, two of which are identical. The overall variation of the coagulation times found were 10% (CV) in 1974 and 8% (CV) in 1975 and 1976. Performance improved rather abruptly at the beginning of 1975, after the application of a tight methodological standardization and improvement by the manufacturer of the thromboplastin preparation (Thrombotest) used by the great majority of the laboratories involved. The main source of variation wasfound to be random error in the Thrombotest determination, approximating 6%. interbatch variation of Thrombotest and inter-aliquot variation of control blood samples both do amount to approximately 3%.

Evaluation of a Gilford "Automatic Enzyme Analyzer" Modified to Assay 60 Samples per Hour

1974 ◽  
Vol 20 (10) ◽  
pp. 1295-1304 ◽  
Author(s):  
Samuel A Morell ◽  
Daniel A Bach ◽  
Valborg E Ayers
Keyword(s):  
Alkaline Phosphatase ◽  
Creatine Kinase ◽  
Lactate Dehydrogenase ◽  
Aspartate Aminotransferase ◽  
Enzyme Assay ◽  
Linear Range ◽  
End Point ◽  
Precision And Accuracy ◽  
Mode 3

Abstract A Gilford 3400 Automatic Enzyme Analyzer has been modified to assay 60 samples per hour in modes 1 and 2 (28 and 61 seconds of incubation) or 30 samples per hour in mode 3 (187 seconds of incubation). The calculation cycle was reduced threefold to print activity based on ΔA/20 s, rather than ΔA/60 s. Linear ranges at 30 and 37 °C for lactate dehydrogenase, aspartate aminotransferase, and alkaline phosphatase were determined with control sera at rates of 60 samples per hour and for creatine kinase activated by dithiothreitol at 30 samples per hour. AutoAnalyzer end-point assays of patients' sera were correlated with the Gilford U/liter values. Application of the Micromedic pipette to the Gilford AEA system provided a convenient mean to study the linear range, precision, and accuracy of an enzyme assay.

Measurement of six enzymes with the Kodak DTSC Module, a physician's office analyzer.

1987 ◽  
Vol 33 (10) ◽  
pp. 1911-1913 ◽  
Author(s):  
R H Ng ◽  
M Altaffer ◽  
M O'Neill ◽  
H Mukadam ◽  
B E Statland
Keyword(s):  
Quality Control ◽  
Alkaline Phosphatase ◽  
Creatine Kinase ◽  
Lactate Dehydrogenase ◽  
Multilayer Film ◽  
Clinical Use ◽  
Gamma Glutamyltransferase ◽  
Quality Control Materials ◽  
Interference Studies

Abstract We evaluated the performance of the Kodak DTSC Module for determination of alanine aminotransferase (ALT; EC 2.6.1.2), aspartate aminotransferase (2.5.1.2), alkaline phosphatase (3.1.3.1), creatine kinase (2.7.3.2), gamma-glutamyltransferase (2.3.2.2), and lactate dehydrogenase (1.1.1.27). The DTSC is a "special chemistry" accessory for the DT60 analyzer; the same multilayer film technology as that of the Ektachem 700 is used. The overall precision, assessed over a three-month period with two serum-based quality control materials, ranged from 2.2 to 8.0%. DTSC results for patients' specimens correlated well with those by the Technicon RA-1000 analyzer. The performance of the analyzer in linearity and interference studies was satisfactory for clinical use. The DTSC is simple to operate and has no technique-dependent step; it should be useful for the physician's office laboratory.

Quality Control of an Automated Differential Isoenzyme Assay of Alkaline Phosphatase, with Use of L-Phenylalanine Inhibition

1972 ◽  
Vol 18 (4) ◽  
pp. 391-392 ◽  
Author(s):  
Fred Cantor ◽  
Sidney Green ◽  
Leo L Stolbach ◽  
William H Fishman
Keyword(s):  
Quality Control ◽  
Alkaline Phosphatase ◽  
Control Program ◽  
Total Alkaline Phosphatase ◽  
Quality Control Program ◽  
Total Alkaline Phosphatase Activity ◽  
Standard Curve ◽  
Heat Stable ◽  
One Year ◽  
Total Alkaline

Abstract A quality-control program, in which a heat-stable human alkaline phosphatase preparation is used to monitor the performance of an automated alkaline phosphatase method, was observed for a year. In the method phenyl phosphate is used as substrate, L-phenylalanine as an intestinal isoenzyme inhibitor, and a phenol standard curve to monitor chromogen formation. Mean total alkaline phosphatase activity was 14.0 ± 0.9 King-Armstrong units (CV, 6.4%), and mean inhibition by L-phenylalanine was 78.2 ± 1.1% (CV, 1.4%). These data compared closely with the data obtained in a collaborating laboratory during the same one-year period.

A Quality-Control Program Based on the Use of Desk-Top Digital Computer

1970 ◽  
Vol 16 (4) ◽  
pp. 305-311 ◽  
Author(s):  
Eugene L Cohen ◽  
George Hermann ◽  
Henry T Sugiura
Keyword(s):  
Quality Control ◽  
Standard Deviation ◽  
Continuous Flow ◽  
Control Program ◽  
Chemical Concentration ◽  
Quality Control Program ◽  
Control Value ◽  
Dual Channel ◽  
Control Serum ◽  
Absorbance Curve

Abstract Programs written for a relatively inexpensive desk-top computer are used to calculate the chemical concentration of any batch of unknowns from a flattened absorbance curve with up to five points produced by single- or dual-channel continuous-flow analyzers and other instrumentation. Any value beyond the limits of the curve is rejected. The programs are then used to evaluate a pooled control serum from previously programmed standard deviation data. The sequence of calculation is such that computation of patient samples stops if the control value lies outside these programmed limits. The system ensures that no patient sample is reported, or even calculated, unless its accompanying control was within acceptable statistical limits. Acceptance of the system by technologists has been outstanding.

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