An International Collaborative Study of Renin Assay: Establishment of the International Reference Preparation of Human Renin

1974 ◽  
Vol 48 (s2) ◽  
pp. 135s-159s ◽  
Author(s):  
D. R. Bangham ◽  
Iris Robertson ◽  
J. I. S. Robertson ◽  
C. J. Robinson ◽  
M. Tree
Keyword(s):  
Collaborative Study ◽  
International Reference ◽  
Human Renin ◽  
Reference Preparation ◽  
International Collaborative ◽  
International Collaborative Study

The Second International Reference Preparation of Thyroid-Stimulating Hormone, Human, for Immunoassay: calibration by bioassay and immunoassay in an international collaborative study

1985 ◽  
Vol 104 (3) ◽  
pp. 367-379 ◽  
Author(s):  
R. E. Gaines Das ◽  
A. F. Bristow
Keyword(s):  
Collaborative Study ◽  
Thyroid Stimulating Hormone ◽  
World Health ◽  
Expert Committee ◽  
International Reference ◽  
Reference Preparation ◽  
International Collaborative ◽  
Health Organization ◽  
International Collaborative Study ◽  
Second International

ABSTRACT Four batches of ampouled materials in ampoules coded 80/558, 81/502, 81/565 and 81/615 were evaluated by 22 laboratories in nine countries in an international collaborative study for their suitability to serve as a replacement for the First International Reference Preparation (IRP) of TSH, Human, for Immunoassay. The ampouled preparations were calibrated by immunoassay and bioassay. The preparation coded 80/558 had satisfactory stability and contained acceptably low levels of contamination with FSH and LH. Estimates of the immunoreactive TSH content of a set of specimens of serum in terms of 80/558 showed agreement in ranking order and no increase in variability compared with estimates made by assay against the First IRP. On the basis of these results, with the agreement of the participants in the study, and with the authorization of the Expert Committee on Biological Standardization of the World Health Organization, the preparation coded 80/558 was established in 1983 as the Second International Reference Preparation of TSH, Human, for Immunoassay, with a defined potency of 37 mi.u./ampoule. Preparations coded 81/502, 81/565 and 81/615 were found suitable to serve as working standards. J. Endocr. (1985) 104, 367–379

International Collaborative Study for the Establishment of the Second International Reference Preparation of Plasmin

1983 ◽  
Vol 50 (03) ◽  
pp. 645-649 ◽  
Author(s):  
P J Gaffney ◽  
M V Mussett
Keyword(s):  
Collaborative Study ◽  
World Health ◽  
Expert Committee ◽  
Glycerol Solution ◽  
International Reference ◽  
Freeze Dried ◽  
Reference Preparation ◽  
International Collaborative ◽  
International Collaborative Study ◽  
Second International

SummaryAn international collaborative study involving seven laboratories was undertaken to assess the suitability of a freeze- dried preparation of human plasmin to replace the current International Reference Preparation (IRP) for plasmin. Chromogenic and fibrinolytic assays were used by all participating laboratories to assess the potencies of the Proposed International Reference Preparation (PIRP) and two other freeze-dried plasmins, one of human and one of porcine originThe data suggest that the PIRP is a more suitable standard for plasmin than the IRP in that the former binds to fibrin whereas only 50% of the latter binds. The PIRP compared well to other plasmin preparations and the potency assays were independent of the assay procedure and substrate used. Degradation studies indicated that the PIRP was far more stable than the glycerol solution of the IRP, surviving for 12 months at 37° C with no significant loss in either amidolytic or fibrinolytic activity. The International Committee for Thrombosis and Haemostasis (Bergamo, 1982) has recommended the use of this material as a standard and it has been established by the Expert Committee on Biological Standardization of the World Health Organization as the second International Reference Preparation for Plasmin with a defined potency of 10 International Units of Plasmin per ampoule.

International Collaborative Study on the Assay of Commercially Available High and Low Molecular Weight Urokinases

1981 ◽  
Vol 45 (01) ◽  
pp. 034-037 ◽  
Author(s):  
P J Gaffney ◽  
S M Tydeman ◽  
T B L Kirkwood ◽  
D Aronson ◽  
G Murano
Keyword(s):  
Molecular Weight ◽  
Collaborative Study ◽  
Relative Potency ◽  
Low Molecular Weight ◽  
International Reference ◽  
Molecular Weights ◽  
Reference Preparation ◽  
International Collaborative ◽  
International Collaborative Study

SummaryUrokinases of different molecular weights are now commercially available. An international collaborative study (eight laboratories) has been conducted to investigate the effect of type and concentration of plasminogen on the assay of two different urokinase preparations against the International Reference Preparation (IRP). Considerable inter-laboratory variation in relative potency estimation was found, and a small effect of plasminogen concentration, independent of type, was apparent.

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

1998 ◽  
Vol 79 (02) ◽  
pp. 439-443 ◽  
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%.

The Establishment of a Standard for Plasminogen (Glu-Type)

1984 ◽  
Vol 51 (03) ◽  
pp. 376-378 ◽  
Author(s):  
P J Gaffney ◽  
A D Curtis
Keyword(s):  
Glutamic Acid ◽  
Collaborative Study ◽  
British Standard ◽  
International Reference ◽  
Reference Preparation ◽  
Human Plasminogen ◽  
Assay Methods ◽  
Full Activation ◽  
Good Agreement ◽  
International Collaborative Study

SummaryFollowing an international collaborative study, a preparation of glutamic acid-(glu-)human plasminogen was established as a British Standard. This study compared the activity of the proposed standard following full activation to plasmin with the 2nd International Reference Preparation (IRP) for plasmin using both fibrinolytic and chromogenic assays. There was good agreement between the results of the two assay methods. The activity of the standard was 10 units per ampoule, these units being equivalent to those defined by the 2nd IRP for plasmin.

scholarly journals A WHO Reference Reagent for lupus (anti-dsDNA) antibodies: international collaborative study to evaluate a candidate preparation

2019 ◽  
Vol 78 (12) ◽  
pp. 1677-1680 ◽  
Author(s):  
Bernard J Fox ◽  
Jason Hockley ◽  
Peter Rigsby ◽  
Carl Dolman ◽  
Pier Luigi Meroni ◽  
...  
Keyword(s):  
Lupus Erythematosus ◽  
Collaborative Study ◽  
Test Methods ◽  
Common Reference ◽  
Double Stranded Dna ◽  
Reference Preparation ◽  
International Collaborative ◽  
And Control ◽  
Dsdna Antibodies ◽  
International Collaborative Study

IntroductionAntibodies against double-stranded DNA (anti-dsDNA) are a specific biomarker for systemic lupus erythematosus (SLE). The first WHO International Standard (IS) for anti-dsDNA (established in 1985), which was used to assign units to diagnostic tests, was exhausted over a decade ago.MethodsPlasma from a patient with SLE was first evaluated in 42 European laboratories. The plasma was thereafter used by the National Institute for Biological Standards and Control to prepare a candidate WHO reference preparation for lupus (anti-dsDNA) antibodies. That preparation, coded 15/174, was subjected to an international collaborative study, including 36 laboratories from 17 countries.ResultsThe plasma mainly contained anti-dsDNA, other anti-chromatin antibodies and anti-Ku. The international collaborative study showed that the field would benefit from 15/174 as a common reference reagent improving differences in performance between different assays. However, no statistically meaningful overall potency or assay parallelism and commutability could be shown.Conclusion15/174 cannot be considered equivalent to the first IS for anti-dsDNA (Wo/80) and was established as a WHO Reference Reagent for lupus (oligo-specific) anti-dsDNA antibodies with a nominal value of 100 units/ampoule. This preparation is intended to be used to align test methods quantifying levels of anti-dsDNA antibodies.

Establishment of the second international standards for porcine and human calcitonins: report of the international collaborative study

1993 ◽  
Vol 128 (5) ◽  
pp. 443-450 ◽  
Author(s):  
Joan M Zanelli ◽  
Rose E Gaines-Das ◽  
P Corran
Keyword(s):  
World Health Organization ◽  
Collaborative Study ◽  
International Standards ◽  
World Health ◽  
International Reference ◽  
International Standard ◽  
Reference Preparation ◽  
Health Organization ◽  
International Collaborative Study

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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