Understanding the 'Silver Book' - An important reference for standardised nomenclature in clinical laboratory sciences.

Clinical laboratories perform a wide menu of testing (examinations). Successful requesting, examination, and ordering in this environment requires clear standardised nomenclature. The Silver Book (SB) is an IUPAC (International Union of Pure and Applied Chemistry) publication, produced with the support of both IUPAC and the IFCC (International Federation of Clinical Chemistry and Laboratory Medicine), that makes recommendations on logical standardised nomenclature, symbols, properties, and units in many disciplines of the clinical laboratory sciences.

Recommendations for clinical laboratory science reports regarding properties, units, and symbols: the NPU format.

The document describes the Nomenclature for Properties and Units (NPU) format developed by the joint committee on Nomenclature for Properties and Units of the IFCC and IUPAC. Basic concepts, in particular system, component, kind-of-property, and unit are defined. Generalities concerning quantities and units, and terminological rules are recalled.

[The virtual slide: a new tool for the External Quality Control for the spermatozoid assessment morphology].

As part of the accreditation procedures, External Quality Control (EQC) must be performed for all biological determinations. In the exploration of male infertility, the spermocytogram is very important because it is often used as first line and an error of interpretation may have dramatic consequences. Alongside the EQC which usely consists of carrying out preparation slides (stained or not), we tested the use of a slide scanned from a stained specimen ("virtual slide").

Traceability of values for catalytic activity concentration of enzymes: a Certified Reference Material for aspartate transaminase.

Background: A new reference material for the liver enzyme aspartate transaminase (AST) (L-aspartate: 2-oxoglutarate-aminotransferase, EC 2.6.1.

[Introducing the new international vocabulary of metrology].

The 3rd edition of the "International vocabulary of metrology - Basic and general concepts and associated terms (VIM)" is a fundamental document for the people who are concerned by metrology. This international standard is bilingual (french/english). The VIM contains definitions of metrological concepts, their hierarchy, numerous explicative notes and examples.

Clinical laboratory sciences data transmission: the NPU coding system.

In health care services, technology requires that correct information be duly available to professionals, citizens and authorities, worldwide. Thus, clinical laboratory sciences require standardized electronic exchanges for results of laboratory examinations. The NPU (Nomenclature, Properties and Units) coding system provides a terminology for identification of result values (property values).

[Recommendations for metrological control of measuring equipments in the clinical laboratories].

The control of the measuring equipment (balances, mass standards, micropipettes, dilutors, volumetric glassware, thermometers...

[Glossary of the acronyms for the institutions concerned by metrology].

Metrology and one of its contributions, metrological traceability represent two fundamental developments for the clinical laboratories. Several international and national institutions take part in these developments. They elaborate recommendations going from concepts to implementation in the clinical laboratories.

Standardization of gamma-glutamyltransferase assays by intermethod calibration. Effect on determining common reference limits.

Background: The improvement of the consistency of gamma-glutamyltransferase (GGT) activity results among different assays after calibration with a common material was estimated. We evaluated if this harmonization could lead to reference limits common to different routine methods.

Methods: Seven laboratories measured GGT activity using their own routine analytical system both according to the manufacturer's recommendation and after calibration with a multi-enzyme calibrator [value assigned by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference procedure].

[Recommendations for expressing uncertainty of measurement of quantitative results in laboratory medicine].

In laboratory medicine, the quantitative results of examinations are interpreted with regard to reference intervals, clinical decision limits or previous results of a patient, from which it is necessary to inform the clinician about the uncertainty of measurement linked to the value of the result. This document explains the problematic of the expression of the uncertainty of measurement. It proposes recommendations concerning a simple way to evaluate uncertainty of measurement using long term internal quality control data and the value of the uncertainty linked to the method calibration.

IFCC primary reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 degrees C.

This paper is the eighth in a series dealing with reference procedures for the measurement of catalytic activity concentrations of enzymes at 37 degrees C and the certification of reference preparations. Other parts deal with: Part 1. The concept of reference procedures for the measurement of catalytic activity concentrations of enzymes; Part 2.

Influence of human haptoglobin polymorphism on oxidative stress induced by free hemoglobin on red blood cells.

Background: An in vitro study was conducted to determine whether haptoglobin phenotypes differed in their protective effect against oxidative stress induced by extracellular hemoglobin on red blood cells.

Methods: Conjugated dienes and thiobarbituric acid-reactive substances (TBARS) were determined in human red blood cell membranes in the presence of hemoglobin and various concentrations of each type of purified haptoglobin. In addition, the release of K+ and lactate dehydrogenase from red blood cells was measured.

Intermethod calibration of alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) results: application to Fibrotest and Actitest scores.

Two multi-component scores (Fibrotest and Actitest) have been proposed to evaluate liver fibrosis or necro-inflammatory lesions as an alternative to liver biopsy. This approach requires standardization of alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) determinations. For this purpose, ALT and GGT values were assigned to a multi-enzyme material using the appropriate primary reference procedure.

A reference material for traceability of aspartate aminotransferase (AST) results.

Standardization of aspartate aminotransferase (AST) determination is highly desirable for inter-laboratory comparison. Serum AST mean values for 20 patients suffering from viral hepatitis showed an inter-laboratory (n = 13) variation of 9.4%.

[Influence of pyridoxal phosphate in measuring aminotransferases activities in patients with viral hepatitis].

Effect of a pyridoxal phosphate (PP) supplementation of reagents used for ALT and AST measurement was studied in serum of 20 patients suffering from viral hepatitis. Measurements of enzyme activities were carried out at 37 degrees C, using an automate (AU 600, Olympus). Significant differences (p < 0.

[Interference of hemolysis on haptoglobin determined by kinetic immunonephelometry and comparison between phenotypes].

The aim of the study was to check if a slight and non visible hemolysis to naked eye such as that induced by blood coagulation could interfere in the immunonephelometric measurement of haptoglobin, and if this interference was dependent on the protein phenotype. Results confirmed that blood coagulation induced a non visible hemolysis whose intensity markedly varied from one specimen to another. Under our conditions (kinetic measurement with a Beckman Coulter immunonephelometer), we observed with the sera a negative interference linked to the hemolysis induced by blood coagulation when compared to corresponding plasmas obtained with lithium heparinate (p < 0,005).

A new continuous automated assay for the determination of intestinal lactase.

Background: A reliable, sensitive and practicable method for the measurement of intestinal lactase activity is needed.

Method: The assay is based on the continuous measurement of released glucose by a coupled hexokinase/glucose-6-phosphate dehydrogenase (HK/G6PDH) reagent.

Results: The procedure was first optimized for lactase from rat intestinal mucosa.

Preparation and characterization of reference materials for human pancreatic lipase: BCR 693 (from human pancreatic juice) and BCR 694 (recombinant).

There is a lack of certified reference material (CRM) for lipase catalytic activity. Consequently between-method comparability is very poor. The aim of this study was to produce two lipase CRMs, one from human pancreatic juice (BCR 693), and another using recombinant technologies (BCR 694).