International reference preparations for standardization of biological medicinal products.

International standards are prepared as materials assigned an arbitrary unitage for a biological activity by the Expert Committee on Biological Standardization of the World Health Organization. Working reference materials are calibrated against international standards giving a common unit of measurement between laboratories. The references are assessed by a collaborative study including all relevant assays rather than by a single reference method as in the SI (Le Système international d'unités) system and the unitage assigned is an arbitrary value derived from a consensus of all valid methods. The process has proved valuable in assaying the activity of therapeutic biological medicines and in standardizing certain types of diagnostics. Issues arise with maintaining the unit when the primary reference must be replaced and to some extent in assessing the commutability of the reference with real life analytes.

A revolution without tooth and claw-redefining the physical base units.

A case study is presented of a recent proposal by the major metrology institutes to redefine four of the physical base units, namely kilogram, ampere, mole, and kelvin. The episode shows a number of features that are unusual for progress in an objective science: for example, the progress is not triggered by experimental discoveries or theoretical innovations; also, the new definitions are eventually implemented by means of a voting process. In the philosophical analysis, I will first argue that the episode provides considerable evidence for confirmation holism, i.e. the claim that central statements in fundamental science cannot be tested in isolation; second, that the episode satisfies many of the criteria which Kuhn requires for scientific revolutions even though one would naturally classify it as normal science. These two observations are interrelated since holism can provide within normal science a possible source of future revolutionary periods.

Mass or molar? Recommendations for reporting concentrations of therapeutic drugs.

A working party (WP) from the Australasian Association of Clinical Biochemists, Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists, Royal College of Pathologists of Australasia and Royal Australasian College of Physicians recommends the following: *mass units should be used for reporting therapeutic drug concentrations in Australia and New Zealand; and the litre (L) should be used as the denominator when expressing concentration. Examples of these units are mg/L and µg/L Exceptions to these principles include: *drugs for which there is current uniformity of reporting and supporting information using molar units, notably lithium (mmol/L) and methotrexate (µmol/L); *drugs that are also present as endogenous substances, where the units used routinely should continue to be used. This applies to many substances, including minerals (eg, iron; µmol/L), vitamins (eg, vitamin D; nmol/L) and hormones (eg, thyroxine; pmol/L). *drugs for which the denominator is not a 198 of fluid and there is international uniformity of reporting (eg, thiopurine metabolites; per 109 red blood cells). These recommendations relate to drugs that are used therapeutically, whether measured for therapeutic drug monitoring purposes or for assessment of overdose. Other substances, such as drugs of misuse, heavy metals or environmental toxins, were not considered by the WP and are thus not covered by this document. These recommendations should also be applied to other supporting documentation such as published guidelines, journal articles and websites. The implementation of these recommendations in New Zealand is subject to local confirmation.

Evaluation of a candidate International Standard for Meningococcal Group C polysaccharide.

Meningococcal group C (MenC) plain polysaccharide (PS) and conjugate vaccines are primarily evaluated by physicochemical methods to ensure that batches are consistently manufactured. As different assays are employed to quantify the MenC PS content of final formulations and bulk intermediaries, there is a need for an International MenC PS Standard to calibrate internal references used in the different laboratories. Twelve laboratories from nine different countries participated in a collaborative study to determine the MenC PS content of a candidate International Standard MenC PS preparation (08/214) and to assess its suitability. On the basis of the results from this study the candidate standard 08/214 was established as an International Standard for the quantification of MenC PS content in vaccines and components. It has a content of 1.192 ± 0.192 mg MenC PS/ampoule (expanded uncertainty with coverage factor of k = 2.365 corresponding to a 95% level of confidence), as determined by the resorcinol assays carried out by eight of the participating laboratories. The standard is available from The National Institute of Biological Standards and Control who act as guardians and distributors of the material under the auspices of WHO.

Estimating alcohol content of traditional brew in Western Kenya using culturally relevant methods: the case for cost over volume.

Traditional homemade brew is believed to represent the highest proportion of alcohol use in sub-Saharan Africa. In Eldoret, Kenya, two types of brew are common: chang'aa, spirits, and busaa, maize beer. Local residents refer to the amount of brew consumed by the amount of money spent, suggesting a culturally relevant estimation method. The purposes of this study were to analyze ethanol content of chang'aa and busaa; and to compare two methods of alcohol estimation: use by cost, and use by volume, the latter the current international standard. Laboratory results showed mean ethanol content was 34% (SD = 14%) for chang'aa and 4% (SD = 1%) for busaa. Standard drink unit equivalents for chang'aa and busaa, respectively, were 2 and 1.3 (US) and 3.5 and 2.3 (Great Britain). Using a computational approach, both methods demonstrated comparable results. We conclude that cost estimation of alcohol content is more culturally relevant and does not differ in accuracy from the international standard.

Development of automatic systems for the ionising radiation metrology at the ENEA-IRP secondary standard laboratory.

The ENEA IRP Secondary Standard Dosimetry Laboratory of Bologna (Italy) has been operated for more than 30 y as a secondary standard laboratory for X rays, gamma, beta and neutron radiation metrology. For photon radiation, the instruments for radiation protection and clinical dosimetry are calibrated in agreement with the ISO standards, using remotely controlled irradiation units: two 60Co, one 137Cs and three X-ray units (160, 320 and 420 kV, respectively). The calibration procedures, approved by the National Primary Laboratory, have been recently implemented in a software package, which controls the irradiation units and acquires the reference measurements. The system, developed at the laboratory under the LabVIEW programming language, guarantees a constant surveillance of all devices and operations, avoids procedural mistakes and automates the record-keeping and reporting activities. This results in an increase in the reliability of the calibration service.

Immunity status against poliomyelitis in Germany: determination of cut-off values in International Units.

BACKGROUND: To prevent importations of wild polioviruses into a polio free region a high level of population immunity must be kept. Standard methodology for determination of polio antibodies is a feature aimed at obtaining consistent results. An International Standard Serum for polio antibodies exists, but no protective level in International Units is defined. METHODS: A representative study was carried out in order to determine the serological status against poliomyelitis in Germany (n = 2564, age 18-79 years). Furthermore, sera from persons aged less than 18 years were included (n = 881). Microneutralization test has been used for determination of antibody levels. Results have been expressed in International Units. RESULTS: The results of this study indicate that the cut-off level for polio antibodies is 0.075 IU/ml for Polio 1, 0.180 IU/ml for Polio 2 and 0.080 IU/ml for Polio 3. Neutralizing antibodies against poliovirus type 1, 2 and 3 were detected in 96.2%, 96.8% and 89.6% of samples, respectively. CONCLUSIONS: Overall, this seroprevalence indicates a very high level of immunity of the general population. It must be kept after the switch of immunization strategy from attenuated to inactivated vaccine in Germany.

SI units: how systematic and how international are they?

Despite the fact that the use of SI units should standardize the reporting of results in chemical pathology, there is still considerable confusion in some areas about the accepted conventions. This confusion is particularly rife in reporting results of thyroxine, and, to a lesser extent, of lipid assays.

Units for reporting the results of toxicological measurements.

A survey of hospital laboratories and current literature revealed that there is a considerable diversity of units employed for reporting the results of toxicological assays. Consideration is given to some of the problems and difficulties that arise from the use of SI units for reporting drug analyses, resulting from a lack of uniformity.

Control of oral anticoagulant therapy.

In an effort better to standardize the control of oral anticoagulant therapy, it has recently been recommended that the prothrombin time be reported in the form of an International Normalized Ratio (INR) based upon calibration of the locally employed thromboplastin with an International Reference Preparation. It has been demonstrated in our laboratory that the INR does minimize the differences in results which ensue from variations in the source of thromboplastin and instrumentation and should hopefully allow for better interlaboratory comparisons in the future. Recent studies have also suggested that many American patients tend to be over anticoagulated and at greater risk for hemorrhage. Based upon those findings, over 40 percent of our specimens were above the currently recommended levels.

Scientific medicine and Système International units.

The Système International, a modern version of the metric system, is being introduced into American medicine. The most compelling reason for this is that a worldwide standardization of weights and measures is taking place, and American medicine should take part in this process. A subsidiary advantage is that units of measurement used in clinical laboratories throughout the United States will be standardized as well. It is possible that expressing concentrations in moles per liter rather than as weight per volume will reveal clinically useful chemical relationships, but this remains unproved. Transition to Système International units will require use of different reference ranges, and there will be a potential for serious misinterpretation of laboratory data unless well-planned educational programs are instituted before the change.

[Significance and development of the application of the International System of Units )SI-WHO 1977) in health care]. / Bedeutung und Entwicklung der Anwendung des Internationalen Einheitensystems (SI-WHO 1977) im Gesundheitswesen.

Normal and pathological metabolic processes in the organism are determined by the amount-of-substance concentration of the metabolites involved. The analytical detection of these amount-of-substance concentrations for diagnostic purposes requires a measuring system that takes these molecular processes into consideration. Moreover, a uniform measuring system is required in order to ensure comparability of the numerical results of laboratory diagnostic investigations. Based on proposals put forward by international scientific medical societies, the WHO therefore decided in 1977 on the common use of a special form of the International System of Units (SI).

[Determining the biological activity of levorin by the international standard of candicidin]. / Opredelenie biologicheskoi aktivnosti levorina po mezhdunarod- nomu standartu kanditsidina.

Levorin and candicidin represent close mixtures of heptaenic components. Their physicochemical and biological properties were also close. The antibiotics showed similar diffusive properties in their assay by the agar diffusion method. This made it possible to determine activity of the Soviet levorin standard by the International candicidin standard. For defining the levorin unit in the international units of candicidin, a scaling ratio of 9 was proposed.

[The system of designation of surgical suture materials]. / Sistema oboznacheniia khirurgicheskikh shovnykh materialov.

The authors suggest a unified system of designation of type--sizes of surgical suture materials of various nature and structure, which removes the existing discrepancy between the numbering of foreign and Soviet threads as well as of Soviet threads produced by different enterprises of the country. Introduction of the new system of metric sizes of the suture threads will allow surgeons to be properly orientated in the choice of the necessary suture material and make easier the work of services engaged in the development and realization of surgical suture materials.

Nomenclatura y unidades de las propiedades biológicas. Recomendación (2016) / Nomenclature and units of biological properties. Recommendation (2016)

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