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Biomedical subjects

D W Moss

Publications and source records attributed to D W Moss.

At least 109 records · Page 6Linked to original sources
PubMed1978

Further observations on the differential precipitation of alkaline phosphatase isoenzymes by ethanol.

The proportions of the total activities of different isoenzymes of human alkaline phosphatase precipitated from serum by ethanol (20% v/v) were: liver phosphatase, 37%; placental phosphatase, 23%; bone phosphatase, 8.0%, and small-intestinal phosphatase, 3.7%. Treatment of the isoenzymes with neuraminidase reduced the percentages of non-intestinal phosphatases precipitated by ethanol to below 10%. Precipitation of intestinal alkaline phosphatase was unaffected by this treatment. The degree of solubility in ethanol therefore appears to be largely determined by the content of terminal sialic acid residues in the alkaline phosphatase molecules. In contrast the stabilities of the isoenzymes to heating at 56 degrees C were not significantly altered by neuraminidase digestion.

Alkaline Phosphatase↗
PubMed1978

Analytical subcellular fractionation studies on different cell types isolated from normal rat liver.

1. Parenchymal, Kupffer and biliary tract cells were isolated from normal rat liver by perfusion with collagenase solution. 2. The specific activities (munits of enzyme activity/mg of protein) of marker enzymes for the principal subcellular organelles were determined in the isolated cell homogenates and compared with whole liver homogenates. 3. The cells were disrupted and the extracts subjected to analytical subcellular fractionation by sucrose-density-gradient centrifugation. Lysosomal integrity was determined by assaying latent beta-N-acetylglucosaminidase in the extracts. 4. Similar subcellular distributions were found for lysosomal, endoplasmic reticulum and plasma membrane marker enzymes in the whole liver and in parenchymal and biliary tract cells. In Kupffer cells, the proportion of these enzymes in the cytosol was significantly increased compared with the other fractions. In addition the equilibrium densities of the various organelles in these cells were lower than those from parenchymal cells.

Animals↗
PubMed1977

Activities of bone and liver alkaline phosphatases in serum in health and disease.

A heat-inactivation method for determining absolute activities of liver and bone alkaline phosphatases in serum has been applied extensively in routine diagnosis. Values for each isoenzyme in healthy individuals of different ages are reported together with results obtained in various diseases. Data from normal subjects show that bone alkaline phosphatase contributes about half the total alkaline phosphatase activity in adults. Liver phosphatase shows a slight increase with age. The method is also able to detect reliably the presence of carcinoplacental isoenzymes.

Adolescent↗
PubMed1977

An automated continuous-monitoring procedure for the determination of acid phosphatase activity in serum.

The method of Hillmann, in which hydrolysis of alpha-naphthyl phosphate by acid phosphatase is coupled to the formation of an alpha-naphthol-Fast Red TR azo-compound, has been adapted for use with the LKB Produkter AB 8600 reaction rate analyzer. Factors which affect the reproducibility of the method are described and its performance is shown to be superior to that of a manual phenyl-phosphate procedure.

Acid Phosphatase↗
PubMed1977

Apoenzyme of aspartate aminotransferase in serum in health and disease.

Aspartate aminotransferase activity has been measured in the sera of normal subjects and in patients with various diseases both with and without addition of pyridoxal phosphate to the assay medium. Considerable quantities of apoaminotransferase were present in almost all samples. In normal subjects this potentially-active enzyme corresponds on average to about half the holoenzyme present before reactivation with pyridoxal phosphate. However, considerable variations between individuals were found in the amounts of apoaminotransferase present in serum, and also between groups of patients with various diseases.

Apoenzymes↗
PubMed1977

The scientific foundations of clinical enzymology.

Clinical enzymology is the study of the activity and properties of enzymes in specimens (usually of blood) taken from patients, as an aid to the diagnosis and understanding of disease. Research in many areas of enzymology is undertaken to strengthen the foundations on which the clinical interpretation of such enzyme measurements rests. Some aspects of this research are briefly described.

Alkaline Phosphatase↗
PubMed1976

Titration of human placental alkaline phosphatase with radioactive orthophosphate.

Human placental alkaline phosphatase incorporates radioactive phosphate specifically and covalently at acid pH. By titration of solutions of the purified enzyme with radioactive orthophosphate, the enzyme was shown to incorporate up to 2 phosphate groups per molecule. No evidence was found to suggest that the two sites had different affinities for phosphate. Similar titrations can be used to determine the molarity of solutions of non-placental alkaline phosphatases of unknown purity, if these also are assumed to possess 2 binding sites per molecule.

Alkaline Phosphatase↗
PubMed1976

An active site peptide from human placental alkaline phosphatase.

A preparation of human placental alkaline phosphatase was labelled covalently at the active site with [32P]orthophosphate. Treatment with trypsin gave essentially one radioactive peptide, the active site peptide, of approximately 2300 molecular weight. Dansylation of the peptide showed that the amino-terminal residue was glycine. After acid hydrolysis the only radioactively-labelled amino acid present was serine phosphate. The amino acid composition was similar to those compositions reported for active site peptides from other alkaline phosphatases.

Alkaline Phosphatase↗