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Biomedical subjects

K Jung

Publications and source records attributed to K Jung.

At least 397 records · Page 22Linked to original sources

Suitability of commercial control sera for the quality control of activity determination of alkaline phosphatase.

The suitability of thirteen commercially available control sera for measuring alkaline phosphatase (EC 3.1.3.1; orthophosphoric acid monoester phosphohydrolase, ALP) activity in human serum was tested. Apart from differences in ALP activity observed in some reconstituted commercial sera, the behaviour of control materials towards experimental variables such as the nature and concentration of the substrate, pH and type of buffer (or PO4-acceptor) together with the composition of the isoenzymes present in human serum highlights the problems and difficulties if commercial materials are to be used as control sera. The half-saturation constants in control sera were in all cases smaller than those of ALP isoenzymes from bone and liver. The shape of substrate activity curves and the pH optimum in most of control sera differed from that of human serum. The discrepant kinetic data of control materials and human serum may mask or suggest changes relevant to commercial quality control serum but not to samples of human serum.

Alkaline Phosphatase↗

Creatine kinase isoenzyme BB in serum of healthy adults and children.

The activity of the creatine kinase isoenzyme BB was determined in the serum of 26 healthy adults and 31 children. The isoenzyme BB could be proved as a normal component in the human serum. In the adults examined, an activity of 0.56 +/- 0.16 I.U./l (x +/- S.D.) was determined. The activity of creatine kinase isoenzyme BB in the serum does not depend on sex but is subject, however, to a strong age dependence. Only at an age of more than 18 years, isoenzyme BB activities adjust to those of adults.

Adult↗

Stability of isoenzymes of alkaline phosphatase in various buffer systems.

The stability of isoenzymes of alkaline phosphatase from liver, bones and small intestine was compared after addition to inactivated serum in the buffer systems: glycine, 2-amino-2-methyl-1-propanol, diethanolamine and 2-amino-2-methyl-1,3-propandiol at 37 degrees C. The mentioned isoenzymes were inactivated to different extents in glycine and 2-amino-2-methyl-1-propanol buffers. In diethanolamine and 2-amino-2-methyl-1,3-propandiol buffers sufficient stability of isoenzymes is obtained so that only these buffers are suitable for activity determinations of alkaline phosphatase at 37 degrees C.

Alkaline Phosphatase↗

Creatine kinase isoenzyme BB in serum of patients undergoing chronic hemodialysis and with kidney transplant.

The activity of creatine kinase isoenzyme BB (CK-BB) was determined in serum of healthy adults and in patients undergoing maintenance hemodialysis and with kidney transplant. In the healthy adults examined, an activity of 0.56 +/- 0.16 U/l (mean +/- SD) was found. The arithmetic mean of CK-BB activity in patients with renal insufficiency under hemodialysis was 1.42 +/- 0.87 U/l and differed from that of the healthy group. The CK-BB activity in patients with kidney transplant was not different from that of the control group. The occurrence of CK-BB in serum is discussed from diagnostic and methodological point of view.

Adult↗

Influence of Mg2+ ions on the activity measurement of isoenzymes of alkaline phosphatase.

The activity of alkaline phosphatase isoenzymes from liver, bone and small intestine is differently influenced by Mg2+. The stimulation of isoenzymes from liver and bone is higher by Mg2+ ions than in the case of isoenzymes from small intestine. An obligatory preincubation of the serum sample in a buffer-Mg2+ mixture is necessary to avoid difficulties which may arise in the kinetic determination of alkaline phosphatase activity under extreme conditions, i.e. low Mg2+ concentration in serum, the necessity of dilution of the sample or the high isoenzyme content from liver or bone in the serum.

Alkaline Phosphatase↗

The apoenzyme of aspartate aminotransferase and alanine aminotransferase in the serum of healthy persons and patients suffering from liver diseases.

In activity determination with addition of pyridoxal 5'-phosphate (P-5-P), aspartate aminotransferase (AST) activity increases by 6.5 U/l and that of alanine aminotransferase (ALT) by 2.5 U/l in the serum of healthy persons. This corresponds to a relative stimulation of initial activity by 37% and 15.2%, respectively. ApoAST activity in patients with chronic liver diseases is not changed as compared with that of healthy persons, the relative stimulation rate, however, is significantly smaller. ApoALT activity and corresponding relative stimulation is significantly greater as compared with healthy persons. In the case of acute viral hepatitis, a decrease of AST and ALT activity is followed by a decrease of apoenzyme activity in the course of disease. Diagnostic evidence of determinations of aminotransferase activities could not be improved by addition of P-5-P.

Alanine Transaminase↗

Lecithin: cholesterol acyltransferase activity in patients with chronic liver diseases and positive LP-X tests.

Lecithin: cholesterol acyltransferase activity has been measured in serum from patients with various liver disorders and positive LP-X tests and from healthy subjects. Statistical analysis indicated that lecithin: cholesterol acyltransferase activity provided no help in the discrimination between the persons of both groups although the mean activities differed significantly.

Chronic Disease↗

Comparative determinations of aminotransferase activities in serum with so-called "optimised" methods.

Comparative determinations of aspartate aminotransferase and alanine aminotransferase activities were made with so-called "optimised" methods introduced in the G.D.R., G.F.R. and Scandinavia. By means of the paired t-test significant differences could be established. These differences are partly due to different reaction conditions. For practical clinical aspects these differences should be of little relevance. In comparison with above-mentioned activites determined at 37 degrees C, aspartate aminotransferase activities measured with the IFCC reference method are lower by about 30 percent.

Alanine Transaminase↗