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

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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.

Puntualizaciones acerca de las unidades de toxina botulínica tipo A / Some clarifications regarding botulinum toxin type A units

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Algorithms for international atomic time.

This article reviews the creation and technical evolution of atomic time scales. In particular, we focus our attention on the method of calculation and the characteristics of International Atomic Time (TAI), and show how it is disseminated at the ultimate level of precision.

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.

The 2007 International Vocabulary of Metrology (VIM), JCGM 200:2008 [ISO/IEC Guide 99]: Meeting the need for intercontinentally understood concepts and their associated intercontinentally agreed terms.

Unambiguous and consistent concepts and terms such as measurand, metrological traceability, measurement uncertainty, comparability of measurement results, target measurement uncertainty, etc., must govern the description of measurements in order to enable a valid comparison of measurement results. That is not yet the case as numerous workshops over the last decade have shown worldwide and as chemical literature continuously displays. For international trade in food and feed to be fair, for border-crossing implementation of environmental regulations to be the same for all parties concerned, for interchangeability of results of clinical measurements to become a reality, for any border-crossing interpretation of measurement results in chemistry to become possible, well understood and mutually accepted, common and well defined concepts and terms are essential. Similarly, their translations from one language--English--to 30-40 other languages, must be realized and fixed unequivocally. Countries using English as common language have not yet fully realized that they are at a considerable advantage over countries where such translated terms describing concepts may not yet be available, let alone understood and accepted. A number of ambiguities in the definitions and terms are described which illustrate the importance of the revision (1997-2007) of the International Vocabulary of Metrology (VIM), henceforth conveniently called "VIM3", especially since chemical measurement is covered in this VIM for the first time in history: 'measurand' 'metrological comparability of measurement results' 'metrology' 'metrological compatibility of measurement results' 'measurement result' 'metrological traceability' (incl 'to the SI') 'measurement uncertainty' 'target measurement uncertainty' 'calibration hierarchy' 'quantity' and many others. It is concluded that the revised VIM is of primordial importance for good understanding within and between the measurement communities worldwide.

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.

Introduction: the fundamental constants of physics, precision measurements and the base units of the SI.

This is a short introductory note to the texts of lectures presented at a Royal Society Discussion meeting held on 14-15 February 2005 and now published in this issue of Philosophical Transactions A. It contains a brief resumé of the papers in the order they were presented at the meeting. This issue contains the texts of all of the presentations except those of Christophe Salomon, on cold atom clocks and tests of fundamental theory, and Francis Everitt, on Gravity Probe B, which were, unfortunately, not available.

The determination of best values of the fundamental physical constants.

The purpose of this paper is to provide an overview of how a self-consistent set of 'best values' of the fundamental physical constants for use worldwide by all of science and technology is obtained from all of the relevant data available at a given point in time. The basis of the discussion is the 2002 Committee on Data for Science and Technology (CODATA) least-squares adjustment of the values of the constants, the most recent such study available, which was carried out under the auspices of the CODATA Task group on fundamental constants. A detailed description of the 2002 CODATA adjustment, which took into account all relevant data available by 31 December 2002, plus selected data that became available by Fall of 2003, may be found in the January 2005 issue of the Reviews of Modern Physics. Although the latter publication includes the full set of CODATA recommended values of the fundamental constants resulting from the 2002 adjustment, the set is also available electronically at http://physics.nist.gov/constants.