An international collaborative study to establish the World Health Organization 2nd International Standard for Factor VII Concentrate: communication from the SSC of the ISTH

The biological potency of calcitonins in clinical use in long-term treatment of Paget's disease of bone and, increasingly, in osteoporosis is usually expressed in international units defined by the relevant World Health Organization international reference preparation. The international reference preparations for porcine and human calcitonins were ampouled in 1970 and stocks are now exhausted. Replacement standards were ampouled in 1989 and have been evaluated and calibrated by an international collaborative study comprising 16 laboratories in 12 countries. Evaluations included high-performance liquid chromatography and in vitro bioassay; calibration of each new ampouled preparation in terms of its international reference preparation was by in vivo rat hypocalcaemia bioassay. On the basis of the results of the study and with the agreement of the participants, replacement standards were established by the Expert Committee on Biological Standardization of the World Health Organization in 1991: the international standard for porcine calcitonin (ampoule code 89/540), with an assigned potency of 0.8 international units per ampoule, and the international standard for human calcitonin, with an assigned potency of 17.5 international units per ampoule. Both international standards appeared to be sufficiently stable to serve as the international standards for in vivo biological assays. Comparison of the two species of calcitonin in the same hypocalcaemia assay showed that they were approximately equipotent when the doses were given intravenously but that the human peptide was four- to sixfold more potent than porcine calcitonin when doses were given subcutaneously, emphasizing the need to compare "like with like".

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Results of the First World Health Organization International Collaborative Study of Detection of Human Papillomavirus DNA

Journal of Clinical Microbiology ◽

10.1128/jcm.44.2.571-579.2006 ◽

2006 ◽

Vol 44 (2) ◽

pp. 571-579 ◽

Cited By ~ 42

Author(s):

W. G. V. Quint ◽

S. R. Pagliusi ◽

N. Lelie ◽

E.-M. de Villiers ◽

C. M. Wheeler ◽

...

Keyword(s):

Human Papillomavirus ◽

World Health Organization ◽

Collaborative Study ◽

World Health ◽

International Collaborative ◽

Health Organization ◽

First World ◽

Papillomavirus Dna ◽

International Collaborative Study

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An International Standard for whole blood folate: evaluation of a lyophilised haemolysate in an international collaborative study

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm.2004.090 ◽

2004 ◽

Vol 42 (5) ◽

Cited By ~ 17

Author(s):

Susan J. Thorpe ◽

Dawn Sands ◽

Alan B. Heath ◽

Malcolm S. Hamilton ◽

Sheena Blackmore ◽

...

Keyword(s):

Whole Blood ◽

Collaborative Study ◽

World Health ◽

Expert Committee ◽

International Standard ◽

Accelerated Degradation ◽

Biological Standardization ◽

The World ◽

Health Organization ◽

International Collaborative Study

AbstractFolate measurements, particularly for whole blood, show wide inter-laboratory and inter-methodology variability. This variability appears to be due in part to the lack of internationally accepted reference materials. A whole blood haemolysate, lyophilised in ampoules and designated 95/528, was therefore evaluated by 15 laboratories in five countries for its suitability as an International Standard (IS) for whole blood folate. The preparation was assayed using a variety of microbiological and protein-binding methodologies against local standards and calibrators. A consensus folate content was assigned to 95/528. The inclusion of three whole blood samples in the study with widely differing folate levels demonstrated a considerable reduction in inter-laboratory variability when the folate content of the samples was determined relative to the proposed IS 95/528 rather than to laboratories' local standards and calibrators. Accelerated degradation studies indicated that the folate content of 95/528 is stable when stored at −20°C. On the basis of the results presented here, the World Health Organization Expert Committee on Biological Standardization established 95/528 as an IS for whole blood folate.

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The World Health Organization international collaborative study of medical care utilization: A summary of methodological studies and preliminary findings

Social Science & Medicine (1967) ◽

10.1016/0037-7856(74)90094-8 ◽

1974 ◽

Vol 8 (5) ◽

pp. 255-262 ◽

Cited By ~ 2

Author(s):

David L. Rabin ◽

Esko Kalimo ◽

John H. Mabry

Keyword(s):

Medical Care ◽

World Health Organization ◽

Collaborative Study ◽

World Health ◽

Care Utilization ◽

Medical Care Utilization ◽

The World ◽

Health Organization ◽

Methodological Studies ◽

International Collaborative Study

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A Collaborative Study to Establish the Second International Standard for Streptokinase

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647298 ◽

1990 ◽

Vol 64 (02) ◽

pp. 267-269 ◽

Cited By ~ 7

Author(s):

A B Heath ◽

P J Gaffney

Keyword(s):

High Purity ◽

Collaborative Study ◽

World Health Organisation ◽

World Health ◽

Clot Lysis ◽

Current Standard ◽

International Standard ◽

Accelerated Degradation ◽

The World ◽

International Collaborative Study

SummaryAn International Standard for Streptokinase - Streptodomase (62/7) has been used to calibrate high purity clinical batches of SK since 1965. An international collaborative study, involving six laboratories, was undertaken to replace this standard with a high purity standard for SK. Two candidate preparations (88/826 and 88/824) were compared by a clot lysis assay with the current standard (62/7). Potencies of 671 i.u. and 461 i.u. were established for preparations A (88/826) and B (88/824), respectively.Either preparation appeared suitable to serve as a standard for SK. However, each ampoule of preparation A (88/826) contains a more appropriate amount of SK activity for potency testing, and is therefore preferred. Accelerated degradation tests indicate that preparation A (88/826) is very stable.The high purity streptokinase preparation, coded 88/826, has been established by the World Health Organisation as the 2nd International Standard for Streptokinase, with an assigned potency of 700 i.u. per ampoule.

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International Collaborative Study for the Calibration of a Proposed Reference Preparation for Thromboplastin, Human Recombinant, Plain

Thrombosis and Haemostasis ◽

10.1055/s-0037-1615004 ◽

1998 ◽

Vol 79 (02) ◽

pp. 439-443 ◽

Cited By ~ 32

Author(s):

Veena Chantarangkul ◽

Barbara Negri ◽

Marigrazia Clerici ◽

Pier Mannuccio Mannucci ◽

Armando Tripodi

Keyword(s):

Collaborative Study ◽

Mean Value ◽

World Health ◽

Practical Reasons ◽

Calibration Model ◽

Average Value ◽

Reference Preparation ◽

International Collaborative ◽

Health Organization ◽

International Collaborative Study

SummaryStocks of the International Reference Preparation (IRP) for thromboplastin, human, plain, coded BCT/253 and held by the World Health Organization (WHO) are nearly exhausted and must be replaced. For practical reasons the choice of the replacement candidate was restricted to two available human recombinant preparations which were coded as X/95 and Y/95 and calibrated in an international collaborative study involving 19 laboratories from Europe, Australia, Canada and Argentina. To minimize the differences between routes of calibration, the two candidates were calibrated against the existing WHO-IRP from human, rabbit and bovine origin and the final ISI was the resultant average value. On the basis of predefined criteria (i.e., within- and between-laboratory precision of the calibration and the conformity to the calibration model), X/95 was the preferred candidate. The assigned ISI (SE of the mean) value is 0.940 (0.0060) and the interlaboratory coefficient of variation 4.7%.

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