Activity Of Bovine Serum Research Articles

Detecting endotoxin activity in bovine serum using an automated testing system.

The aim of the present study was to compare the ability of the commercially available portable test system (PTSTM) to detect endotoxin activity in bovine serum, with that of the traditional LAL-kinetic turbidimetric (KT) and chromogenic (KC) assays. Prior to testing, serum samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTSTM was not significantly different from that of the traditional LAL-based assays. The results using PTSTM correlated with those using KT (r2=0.963, P<0.001) or KC assays (r2=0.982, P<0.001). Based on these findings, the PTSTM could be applied as a simplified system to assess endotoxin activity in bovine serum.

Solvent and thermal stability, and pH kinetics, of proline-specific dipeptidyl peptidase IV-like enzyme from bovine serum

Proline-specific dipeptidyl peptidase-like (DPP IV; EC 3.4.14.5) activity in bovine serum has attracted little attention despite its ready availability and the paucity of useful proline-cleaving enzymes. Bovine serum DPP IV-like peptidase is very tolerant of organic solvents, particularly acetonitrile: upon incubation for 1 h at room temperature in 70% acetonitrile, 47% dimethylformamide, 54% DMSO and 33% tetrahydrofuran (v/v concentrations) followed by dilution into the standard assay mixture, the enzyme retained half of its aqueous activity. As for thermal performance in aqueous buffer, its relative activity increased up to 50 °C. Upon thermoinactivation at 71 °C, pH 8.0 (samples removed periodically, cooled on ice, then assayed under optimal conditions), residual activities over short times fit a first-order decay with a k-value of 0.071 ± 0.0034 min −1. Over longer times, residual activities fit to a double exponential decay with k 1 and k 2 values of 0.218 ± 0.025 min −1 (46 ± 4% of overall decay) and 0.040 ± 0.002 min −1 (54 ± 4% of overall decay), respectively. The enzyme's solvent and thermal tolerances suggest that it may have potential for use as a biocatalyst in industry. Kinetic analysis with the fluorogenic substrate Gly-Pro-7-aminomethylcoumarin over a range of pH values indicated two p K values at 6.18 ± 0.07 and at 9.70 ± 0.50. We ascribe the lower value to the active site histidine; the higher may be due to the active site serine or to a free amino group in the substrate.

Identification of lipopolysaccharide binding protein-like activity in bovine serum.

Identification of lipopolysaccharide binding protein-like activity in bovine serum.

Glutathione peroxidase activity in bovine serum and erythrocytes in relation to selenium concentrations of blood, serum and liver

The concentration of selenium (Se) in liver, serum and whole blood, and the activity of glutathione peroxidase (GSH-px) in serum and erythrocytes were monitored for seven months after the administration of Se to Se-deficient calves. There was a rapid increase in Se concentration in liver and serum, followed by an exponential decline with half-lives of 22.1 +/- 0.2 days and 28.3 +/- 2.0 days respectively. Whole blood Se concentration also increased rapidly but declined more slowly than liver or serum Se concentraations. The rise in Se concentration and GSH-px activity in erythrocytes was delayed and both levels remained elevated several months after liver and serum Se concentrations had become marginal or deficient. GSH-px activity in serum increased more rapidly after dosing and declined more rapidly than GSH-px activity in erythrocytes. The results suggest that liver and serum Se concentration and serum GSH-px activity respond to changes in dietary Se intake more rapidly than either whole blood Se or erythrocyte GSH-px activity. Two-monthly administrations of Se, at the current recommended therapeutic dose (0.1 mg Se/kg as sodium selenate) appears to be necessary to maintain adequate Se levels in calves on Se-deficient pasture.

Bovine Reaginic Antibody

A method of utilizing morphological changes in rat mast cells to determine reaginic antibody activity in bovine serum is described. This technique, which has been shown to be useful for the diagnosis of allergies in man, relies on the ability of antigen to degranulate mast cells sensitized with allergic serum. Experiments with radioactively-labelled allergic bovine globulin indicated the specificity of the binding of such proteins to rat mast cells. Cross-reaction between reaginic bovine antibody and human IgE was shown by a binding assay involving the uptake of &lt;sup&gt;125&lt;/sup&gt;I-labelled anti-human IgE globulin by mast cells incubated with bovine passive cutaneous anaphylaxis positive globulin.

Determination of amylase activity in bovine serum and its association with the Ami and Amll loci

SummaryAmylase activity has been estimated in the sera of 213 cattle by an amyloclastic method with potato amylose as the substrate with the addition of CaCl2. The method has been developed from that of Street and Close to overcome the problems of the high colour of bovine serum which would otherwise interfere with the assay. A relationship has been found between the serum amylase genotype detected on starch‐gel and the total enzyme activity. The enzymes AmI‐B and AmII‐B in homozygous combinations have been found to have the highest activities. Age of animal has no significant effect on the total enzyme activity. Activity has been investigated in sera from three separate cattle populations and it has been found to be a highly heritable character. Heritability estimates of 49 % and 39 % by sib analysis and 75 % by the twin method have been obtained.

Immunoconglutinin and total conglutinating activity in bovine serum.

Immunoconglutinin and total conglutinating activity in bovine serum.

Serum alkaline phosphatase activity in cattle

Some biochemical properties of isoenzymes of alkaline phosphatase were examined in extracts of bovine tissues. The value of isoenzyme analysis of alkaline phosphatase activity in bovine serum as a diagnostic aid was studied. Three techniques were compared for routine determination of alkaline phosphatase activity in bovine serum.