Production and certification of secondary enzyme reference materials (ERMs). Part 1: Preparation of the sera and some of their properties.

1986 ◽  
Vol 32 (10) ◽  
pp. 1901-1905 ◽  
Author(s):  
J C Koedam ◽  
G M Steentjes ◽  
S Buitenhuis ◽  
E Schmidt ◽  
R Klauke

Abstract We produced three batches of a human-serum-based enzyme reference material (ERM) enriched with human aspartate aminotransferase (EC 2.6.1.1), alanine aminotransferase (EC 2.6.1.2), creatine kinase (EC 2.7.3.2), and lactate dehydrogenase (EC 1.1.1.27). The added enzymes were not exhaustively purified; thus the final ERMs contained some enzymes as contaminants, of which only glutamate dehydrogenase activity might interfere. The stability during storage and after reconstitution was good. The commutability of the four enzymes in the three ERM batches was also good, except when German or Scandinavian methods for aminotransferases were involved. The temperature-conversion factors for the ERMs were equivalent to those for patients' sera. Reactivation after reconstitution was complete within 5 min and was independent of the temperature of the reconstitution fluid. We believe that these secondary ERMs will aid in the transfer of accuracy between well-defined reference methods and daily working methods so that clinical enzymology results will become more comparable from laboratory to laboratory.

2014 ◽  
Vol 9 (1) ◽  
pp. 86-91 ◽  
Author(s):  
Qichen Jiang ◽  
Adila Dilixiati ◽  
Wenyi Zhang ◽  
Wen Li ◽  
Qing Wang ◽  
...  

AbstractThe metabolic response of the freshwater prawn, Macrobrachium nipponense to nitrite toxicity was evaluated. The prawns were exposed to 0, 1, 2, 3 and 4 mg L−1 NO2-N concentrations for 48 h. The metabolic parameters in muscle were measured after 12, 24 and 48 h. Glucose level significantly increased after 24 h. Exposure to lower nitrite concentrations (1 and 2 mg L−1) resulted in significant increases in alanine aminotransferase (ALT) activities after 24 and 48 h. Aspartate aminotransferase (AST) activities treated with 2 and 3 mg L−1 nitrite-N at 48 h were significantly higher than those at 12 and 24 h. Intermediate sublethal nitrite concentrations produced significant elevations in lactate dehydrogenase (LDH) activities from 12 h up to 48 h. No significant changes were detected in any of the groups for triglycerides and creatine kinase (CK). To satisfy the increased energy demands caused by acute nitrite exposure, mobilization of lipids is not the main reason while utilization of amino acids seems to play a more important role. The results would be helpful for aquaculture farmers to prevent a potential depression of productivity caused by elevated nitrite levels.


1987 ◽  
Vol 21 (1) ◽  
pp. 60-67 ◽  
Author(s):  
C. W. Davy ◽  
P. N. Trennery ◽  
J. G. Edmunds ◽  
J. F. B. Altman ◽  
D. A. Eichler

An investigation of raised plasma aspartate aminotransferase (AST) in marmosets after intramuscular ketamine injection suggested a local myotoxicity. This was confirmed by a range of histopathological findings from myofibrillar striation loss to necrosis. In addition to the elevations in AST levels, creatine kinase and the lactate dehydrogenase-5 isoenzyme levels were elevated. It was further demonstrated that, although the physical properties of the injectable solution (pH, osmolality) and to a lesser extent the injection procedure itself caused slight changes in plasma enzyme levels, the ketamine was predominantly responsible for the lesion. No hepatic interactions were seen. This effect should be taken into consideration when this anaesthetic is used in the marmoset if the primary objectives of the experiment entail routine blood analyses.


2009 ◽  
Vol 66 (11) ◽  
pp. 892-896
Author(s):  
Olivera Trickovic-Janjic ◽  
Tatjana Cvetkovic ◽  
Mirjana Apostolovic ◽  
Draginja Kojovic ◽  
Ljiljana Kostadinovic ◽  
...  

Introduction/Aim. By analyzing activity of some of the enzymes normally present in the saliva and the level of malondialdehyde in gingivitis, it is possible to estimate the functional condition of parodontium, and the examined parameters can be considered as biochemical markers of its functional condition. The aim of this paper was to examine activity of alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase, lactate dehydrogenase and the level of malondialdehyde in the saliva of children affected with gingivitis, as well as the values of the mentioned parameters in relation to the level of the inflammation of gingiva. Methods. The research included 120 children at the age of 12.2 with permanent dentition. L?e and Silness gingival index was used to estimate the condition of gingiva, based on which the children were classified into four groups: the children with healthy gingiva (the control groups), the children with mild, moderate and severe inflammation of gingiva (the study group). Enzymes of the saliva were determined by the use of original tests and measured by the autoanalyser (Bio Systems A25, Spain). A modified method with tiobarbituric acid was used to determine malondialdehyde in nonstimulated mixed saliva. Results. The results of the examined enzyme activity and the level of malondialdehyde in the saliva of the study groups showed statistically considerably higher values for the level of malondialdehyde (p < 0.001), for the activity of aspartate aminotransferase and gamma glutamyl transferase (p < 0.01), as well as for alanine aminotransferase (p < 0.05) in comparison with the control group, whereas the activity of lactate dehydrogenase did not show a statistically significant increase. In relation to the level of the inflammation of gingiva, the results of the examination of the enzyme activity in the study groups showed statistically significantly higher values in the group with severe inflammation in comparison with those with mild, as well as the moderate inflammatory, except for the gamma glutamyl transferase, and in the group with moderate inflammation compared to that with the mild one, except for alanine aminotransferase. The results of the examination of the level of malondialdehyde in the saliva of the study groups did not show a statistically significantly increase in relation to the level of the inflammation of gingiva. Conclusion. There is a higher level of alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase and lactate dehydrogenase enzyme activity together with the higher level of malondialdehyde in the saliva of children with gingivitis in comparison with the activity of the same enzymes and the level of malondialdehyde in the saliva of children without gingivitis. The activity of the examined enzymes in the saliva of children with gingivitis increases in relation to the intensity of the pathological process, whereas the level of malondialdehyde shows no significant difference in relation to the level of the inflammation of gingiva.


Author(s):  
Anna Nowakowska ◽  
Dorota Kostrzewa-Nowak ◽  
Rafał Buryta ◽  
Robert Nowak

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.


1973 ◽  
Vol 19 (9) ◽  
pp. 1079-1080
Author(s):  
Ted W Fendley ◽  
Jane M Hochholzer ◽  
Christopher S Frings

Abstract We have evaluated the effect of diluting serum with water or NaCl solution (8.5 or 9.0 g/liter) before assaying by a manual method for creatine kinase (EC 2.7.3.2), alkaline phosphatase (EC 3.1.3.1), lactate dehydrogenase (EC 1.1.1.27), and aspartate aminotransferase (EC 2.6.1.1) activity. The t test and the F test show no significant difference in the accuracy and precision of the assays at the 95% confidence level when 100 different samples were compared for each enzyme activity after use of the three diluents.


1992 ◽  
Vol 38 (12) ◽  
pp. 2365-2371 ◽  
Author(s):  
F Schiele ◽  
J Muller ◽  
E Colinet ◽  
G Siest ◽  
P Arzoglou ◽  
...  

Abstract We present the results of a study on performance of a reference material for alanine aminotransferase (ALT, EC 2.6.1.2) and the corresponding IFCC-approved method in an interlaboratory trial involving 13 laboratories. The ALT material was partly purified from pig heart (specific activity, 150 kU/g) and was essentially free of six potentially contaminating enzyme activities, including aspartate aminotransferase (EC 2.6.1.1). The partly purified ALT was lyophilized in a triethanolamine-buffered matrix, pH 6.4, containing bovine serum albumin and saccharose. Under these conditions, the predicted yearly loss of activity was 0.02% at 4 degrees C and &lt; 0.01% at -20 degrees C. The final blank-corrected results of the accepted set of data gave a mean (SD) of 128.5 (5.1) U/L. The among-laboratory SD was 4.6 U/L and the within-laboratory SD was 2.0 U/L. The certified ALT catalytic concentration in the reconstituted material was 129 U/L with a 0.95 confidence interval of +/- 4 U/L.


1975 ◽  
Vol 21 (3) ◽  
pp. 330-333 ◽  
Author(s):  
Michael M Chang ◽  
Tai Wha Chung

Abstract We show an example of the importance of specifying the form of isoenzyme and source of indicator enzymes to be used in coupled enzymatic assays. When we compared H4 (pig heart) and M4 (rabbit muscle) isoenzymes of lactate dehydrogenase for their suitability as indicator enzymes in the assay for alanine aminotransferase activity, we found that about fourfold as much M4 as H4 was required in terms of lactate dehydrogenase activity to reflect accurately equivalent amounts of alanine aminotransferase activity. Moreover, the substrate specificities of the two isoenzymes differed quantitatively.


Author(s):  
Rose E Gaines Das ◽  
D H Calam ◽  
F L Mitchell ◽  
F P Woodford ◽  
Marion Cawood ◽  
...  

The stability of a preparation of lyophilised serum and its suitability for use as a reference material for routine assays of Cortisol, oestradiol, and progesterone have been studied in four laboratories with a variety of assay systems. Cortisol and oestradiol were also measured by gas chromatography-mass spectrometry. The lyophilised serum was suitable for use in all routine and reference assay methods examined, with between-method variability no greater than that for frozen serum pools. The concentrations of Cortisol, oestradiol, and progesterone were predicted by accelerated degradation studies to decline by 0·01% per annum if the preparations were to be stored at —20°C. The testosterone content of the preparation, determined in one laboratory, provided no evidence for degradation. The preparation can be shipped for use at ambient temperature without deleterious effect.


Our Nature ◽  
1970 ◽  
Vol 3 (1) ◽  
pp. 20-25 ◽  
Author(s):  
H. Bhattacharya ◽  
L. Lun ◽  
G.D. Gomez R.

Biochemical changes in the liver, kidneys and gills of rosy barbs due to toxicity of CCl4 were measured after 96 hour exposure. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), blood urea nitrogen (BUN) and creatinin (CRN), levels were measured. Significant increase in ALP, ALT, LDH and BUN activities were observed in the liver in the treated groups compared to controls (P < 0.05). AST level was significantly higher in the kidneys. This study indicates that the enzymatic activity was comparatively higher in the liver than kidneys or gills, suggesting that the liver is the target organ of CCL4 toxicity to rosy barbs.Keywords: Toxicity, Rosy Barb, CCl4doi:10.3126/on.v3i1.330Our Nature (2005)5:20-25


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