Clinical Enzymology Research Articles

12th international congress for clinical enzymology (ISCE): September 8–10, 1993 Location: Maastricht, Netherlands. Contact: Dr. Robert Rej, ISCE, Wadsworth Laboratories, New York State Department of Health, Albany, NY 12201-0509, USA, Tel. 9518) 473-7130.

12th international congress for clinical enzymology (ISCE): September 8–10, 1993 Location: Maastricht, Netherlands. Contact: Dr. Robert Rej, ISCE, Wadsworth Laboratories, New York State Department of Health, Albany, NY 12201-0509, USA, Tel. 9518) 473-7130.

12th International congress for clinical enzymology (ISCE): November, 1993 Location: Sydney, New South Wales, Australia. Contact: Dr. Robert Rej, ISCE, Wadsworth Laboratories, New York State Department of Health, Albany, NY 12201-0509, USA, Tel. (518) 474-1166, Fax (518) 473-7130.

12th International congress for clinical enzymology (ISCE): November, 1993 Location: Sydney, New South Wales, Australia. Contact: Dr. Robert Rej, ISCE, Wadsworth Laboratories, New York State Department of Health, Albany, NY 12201-0509, USA, Tel. (518) 474-1166, Fax (518) 473-7130.

Veterinary Laboratory Medicine: Interpretation and Diagnosis

Part I: General Discussions. Laboratory Medicine Testing: Specimen Interferences and Clinical Enzymology. Hematopoiesis and Evaluation of the Bone Marrow. Evaluation of Erythrocytic Disorders. Evaluation of Leukocytic Disorders. Evaluation of Hemostasis: Coagulation and Platelet Disorders. Evaluation of Immune-Mediated Disease and Hyperglobulinemia. Evaluation of the Hepatobiliary System and Skeletal Muscle and Lipid Disorders. Evaluation of Exocrine Pancreatic, Intestinal Tract, And Glucose Disorders. Evaluation of Endocrine Function. Assessment of Renal Function, Urinalysis, And Water Balance. Electrolyte and Acid-Base Homeostasis and Disorders. Examination of Cerebrospinal Fluid. Evaluation of Effusions. Examination of Synovial Fluid. The Microscopic Examination of Tissue Specimens Obtained By Fine-Needle Aspiration Biopsy. Part II: Case Histories. Part III: Algorithms. Part IV: Appendix: Normal Values and Conversion Tables. Index.

Elevated extracellular Ca 2+ levels induce type X collagen synthesis in chondrocyte cultures

In 1930 the determination of serum alkaline phosphatase in patients with bone or liver disease ushered in the era of clinical enzymology. The association of elevated (bone) alkaline phosphatase in serum of patients with osteogenic sarcoma was the first evidence that tumor cells themselves produced the enzyme. It became clear, however, in the 1960s that the serum alkaline phosphatase was not a single enzyme but consisted of a family of isozymes originating from liver, bone, intestine, and placenta. This was a consequence of the introduction of a combination of electrophoretic separations, heat inactivation, and organ-specific amino acid inhibitors. This combination of measurements made possible the demonstration of a serum alkaline phosphatase of lung cancer origin, as confirmed by the histochemical visualization in lung cancer of the Regan Isozyme (placental alkaline phosphatase-PLAP). At present, the measurement of PLAP has its greatest utility as a tumor marker in seminoma and ovarian cancer. A PLAP-like isozyme in normal testis and ovary is expressed in these and other neoplasias and appears to be related to rare alleles of placental alkaline phosphatase. Current studies have utilized a panel of monoclonal antibodies to detect useful epitopes that suggest that PLAP and PLAP-like isozymes are coded by different genes. The PLAP gene has now been cloned and sequenced by Millan and others. This fundamental new information is providing a base line that will make it possible to explain the overlapping specificities of intestinal and placental isozymes, the degree of uniqueness of the PLAP-like isozyme, the precise mechanism of uncompetitive inhibition by L-phenylalanine and the evolutionary history of the alkaline phosphatases. Tumor PLAP is an example of oncotrophoblast gene expression.

Reso8th International Congress of Clinical Enzymology

reso8th International Congress of Clinical Enzymology

On the importance of being (stereo) specific

The current era of exciting advances in the molecular and cell biology of the alkaline phosphatase isozymes represents to me ‘the promised land’ towards which I and others have been struggling to reach over forty years. The papers including in the Symposium have given us a picture which can be the platform of knowledge upon which to build future progress. My purpose is to illuminate a key signpost which has guided me along the route of my scientific travels in clinical enzymology. It is both the stereo specificity and organ specificity of amino acid inhibitors of enzymes.

Serum enzymes in the diagnosis of disease in man and animals

The clinical pathologist is concerned with aiding the diagnosis of disease by investigating the disease process in the patient. These investigations seek to identify the pathogen (e.g., toxin, virus, bacterium or parasite) or to detect diagnostic pathological changes by haematology, cytology and biochemistry. Clinical enzymology is a branch of clinical biochemistry which has grown rapidly in the last 50 years. This rapid growth has been associated with the development of methods of enzyme assay. The molecular concentrations of enzymes in serum are very much lower than those of most other metabolites of clinical importance. Only special radioimmunoassay techniques are sufficiently sensitive for the direct determination of serum enzyme protein concentration. Fortunately, enzymes can be determined indirectly by measuring their activity, i.e. their ability to accelerate the particular chemical reactions which they catalyse. Thus the activity of an enzyme may be determined by incubation with its substrate and measurement of loss of substrate, formation of product or change in a coenzyme. Activity varies with temperature, pH, substrate concentrations and the presence of activators or inhibitors, so that enzyme assay conditions must be carefully controlled. It is desirable to saturate the enzyme with substrate to ensure zero-order kinetics during the assay. There is considerable variation in the stability and assay requirements of different enzymes. Enzymes which are very unstable or difficult to assay are of limited value in diagnostic investigations. Practical instructions for many enzyme assays are provided by Bergmeyer ( 1983). Early investigators used a variety of units of enzyme activity. In 1961 the Commission on Enzymes of the International Union of Biochemistry (IUB) recommended a standard international unit (IU) as that amount of enzyme which will catalyse the transformation of 1 micromole of substrate per minute under standard conditions. It is convenient to perform serum enzyme assays at 30°C and to express the results in IU per litre. The newer SI System recommends the “katal” (kat) as the unit of enzyme activity. This is the amount of activity which transforms 1 mole of substrate per second. Thus 1 p kat is equivalent to 60 IU. The enzyme names and numbers recommended

The place of reference materials in clinical enzymology

Standardization embraces two concepts: achievement of a uniform standard of practice, or comparison with a standard of known or defined properties. In clinical enzymology the former concept can be equated with the adoption of recommended standardized methodology, which has had noteworthy successes in improving compgrability of results. The use of enzyme standards or calibrators has received relatively little attention so far, but is increasingly important with the introduction of analysers which cannot readily utilize recommended methods. The main factor in the use of calibrators is that of commutability of calibrators and patients' samples between methods, which must be the subject of thorough experimental tests.

7th International Congress on Clinical Enzymology

7th International Congress on Clinical Enzymology

Clinical Enzymology. A Case-Oriented Approach

Clinical Enzymology. A Case-Oriented Approach

Clinical and biological significance of an isozyme tumor marker—PLAP

In 1930 the determination of serum alkaline phosphatase in patients with bone or liver disease ushered in the era of clinical enzymology. The association of elevated (bone) alkaline phosphatase in serum of patients with osteogenic sarcoma was the first evidence that tumor cells themselves produced the enzyme. It became clear, however, in the 1960s that the serum alkaline phosphatase was not a single enzyme but consisted of a family of isozymes originating from liver, bone, intestine, and placenta. This was a consequence of the introduction of a combination of electrophoretic separations, heat inactivation, and organ-specific amino acid inhibitors. This combination of measurements made possible the demonstration of a serum alkaline phosphatase of lung cancer origin, as confirmed by the histochemical visualization in lung cancer of the Regan Isozyme (placental alkaline phosphatase-PLAP). At present, the measurement of PLAP has its greatest utility as a tumor marker in seminoma and ovarian cancer. A PLAP-like isozyme in normal testis and ovary is expressed in these and other neoplasias and appears to be related to rare alleles of placental alkaline phosphatase. Current studies have utilized a panel of monoclonal antibodies to detect useful epitopes that suggest that PLAP and PLAP-like isozymes are coded by different genes. The PLAP gene has now been cloned and sequenced by Millan and others. This fundamental new information is providing a base line that will make it possible to explain the overlapping specificities of intestinal and placental isozymes, the degree of uniqueness of the PLAP-like isozyme, the precise mechanism of uncompetitive inhibition by L-phenylalanine and the evolutionary history of the alkaline phosphatases. Tumor PLAP is an example of oncotrophoblast gene expression.

Fetal intestinal alkaline phosphatase in serum and amniotic fluid

G iovanni Battista Morgagni (1682-1771) lived in an age in which a description of the signs and symptoms of disease was the main objective of medicine. His insistence on attempting to correlate symptoms observed during life with pathological changes demonstrated after death justly earned him the title of “the father of pathology,” and established this principle as the basis of modern clinical science. Today, molecular changes have been added to morphological changes as the targets of modern attempts to understand disease. Since life consists of a pattern of integrated chemical reactions catalyzed by specific enzymes, clinical enzymology occupies a central place in modern medicine. The human alkaline phosphatases have been exploited for diagnostic purposes for more than 60 years. During that time, an enormous body of observations has accumulated. Often, observation has outrun explanation; however, during the past 25 years in particular, several interpretations have become firmly established and provide a sound foundation for the edifice of clinical use of alkaline phosphatase measurements.

Sixth international congress on clinical enzymology

Sixth international congress on clinical enzymology

Genetic and Molecular Biological Aspects of Clinical Enzymology

Genetic and Molecular Biological Aspects of Clinical Enzymology

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

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.

Reference materials for clinical enzymology: the work of the Community Bureau of Reference of the European Community.

Reference materials for clinical enzymology: the work of the Community Bureau of Reference of the European Community.

Reference materials for clinical enzymology: the work of the Community Bureau of Reference of the European Community.

Journal Article Reference materials for clinical enzymology: the work of the Community Bureau of Reference of the European Community. Get access D W Moss, D W Moss Search for other works by this author on: Oxford Academic Google Scholar F Schiele, F Schiele Search for other works by this author on: Oxford Academic Google Scholar G Siest, G Siest Search for other works by this author on: Oxford Academic Google Scholar E Colinet E Colinet Search for other works by this author on: Oxford Academic Google Scholar Clinical Chemistry, Volume 32, Issue 3, 1 March 1986, Pages 556–558, https://doi.org/10.1093/clinchem/32.3.556 Published: 01 March 1986

Will implementation of ICES delay method standardization in clinical enzymology? Scandinavian Committee on Enzymes.

Will implementation of ICES delay method standardization in clinical enzymology? Scandinavian Committee on Enzymes.

Diagnostic potential of serum and urine glycosidases in acquired diseases

Abstract

Clinical chemistry and enzymology meetings — Israel 1985

Clinical chemistry and enzymology meetings — Israel 1985