INTERNATIONAL COLLABORATIVE STUDY OF N.I.B.S.C. RESEARCH STANDARD FOR HUMAN PARATHYROID HORMONE FOR IMMUNOASSAY

1980 ◽  
Vol 86 (2) ◽  
pp. 291-304 ◽  
Author(s):  
JOAN M. ZANELLI ◽  
ROSE E. GAINES DAS

The use of a Research Standard for human parathyroid hormone (PTH) in a collaborative study by 17 laboratories in ten countries is described. Results of this study showed that the Research Standard was not distinguishable by immunoreactive criteria from the other preparations and laboratory working standards of human PTH included in the study. It was, however, shown to be distinguishable from the International Reference Preparation for Parathyroid Hormone, Bovine, for Immunoassay by immunoreactive criteria and by heterogeneity of estimates in terms of bovine PTH. The Research Standard had appropriate biological activities in three different in-vitro bioassay systems and appeared to be stable under conditions of accelerated degradation. This material in ampoules coded 75/549 is now available internationally as N.I.B.S.C. Research Standard for human PTH for immunoassay.

1976 ◽  
Vol 83 (4) ◽  
pp. 700-710 ◽  
Author(s):  
P. L. Storring ◽  
H. Dixon ◽  
D. R. Bangham

ABSTRACT This paper describes the preparation and nature of the First International Standard for Human Urinary Follicle Stimulating Hormone and for Human Urinary Luteinizing Hormone, for Bioassay, and of two batches of working standard which were prepared from the same material. A collaborative study of these materials was carried out by six laboratories in six different countries. The FSH and LH activities of the Standard were assayed in terms of those of the Second International Reference Preparation of Human Menopausal Gonadotrophins, Urinary, for Bioassay, which it replaces. The results from 20 valid FSH assays and 30 valid LH assays (using four different methods) obtained in this way gave a weighted combined potency estimate for FSH of 53.7 IU, with 95 fiducial limits of 47.2–61.1 IU, and for LH of 46.2 IU, with 95% fiducial limits of 43.3–49.3 IU. Accelerated degradation studies of the Standard stored at elevated temperatures suggested that the stability of both FSH and LH activities under normal storage conditions would be satisfactory. The FSH and LH activities of the two batches of working standard (WS-A and WS-B) were compared with those of the Standard and were not found to differ significantly, except for the LH activity of WS-B which appeared to be slightly higher than that of the Standard. Accelerated degradation studies did not show any significant differences in stability between the Standard and batches of working standards. On the basis of these results the Standard has been established by WHO and allocated a potency for FSH of 54 IU per ampoule and for LH 46 IU per ampoule. The International Units for FSH, Human Urinary, for Bioassay and for LH (ICSH), Human Urinary, for Bioassay are thus defined as the activities contained in 0.11388 mg and 0.13369 mg of the International Standard, respectively.


1984 ◽  
Vol 107 (1) ◽  
pp. 60-69 ◽  
Author(s):  
T. Schettler ◽  
B. Aufm' Kolk ◽  
M.J. Atkinson ◽  
H. Radeke ◽  
C. Enters ◽  
...  

Abstract. A combination of high-performance-liquidchromatography (HPLC), sensitive radioimmunoassays and a homologous in vitro bioassay was used to characterise human parathyroid hormone (hPTH)-peptides in human parathyroid adenoma and plasma. Chromatography of several synthetic hPTH-peptides allows the calibration of the HPLC column. On the basis of sequence hydrophobicity the elution position of peptides can be predicted. A model for the determination of the minimal peptide sequence of each peptide has been developed which based on immunological and physicochemical properties allows the characterisation of unknown hPTH-peptides. Using this technique the heterogeneity of circulating hPTH-peptides in human plasma has been examined. Plasma extracts from healthy individuals, osteoporotic, hyperparathyroid and pseudohyperparathyroid patients were investigated. A uniform pattern in the heterogeneity of hPTH-peptides was detected. Using parathyroid adenoma as reference disease specific changes were characterised.


1995 ◽  
Vol 73 (01) ◽  
pp. 073-081 ◽  
Author(s):  
L Poller ◽  
E A Van der Velde

SummaryIn an international collaborative study three candidate reference and the local APTT reagent have been tested with lyophilized plasmas containing heparin added in vitro and fresh plasmas from heparinized patients to determine whether it was possible to standardize APTT heparin monitoring.The APTT responses of patients with thrombosis were much less to the same concentrations of heparin so only these plasmas were used to calibrate the reagents.A calibration constant (b) was determined for each local APTT system from the orthogonal regression slope of the patients’ and normals’ plasmas. Although the calibration was based on relatively limited numbers of patients’ plasmas the results gave no consistent indication that this method of analysis with the reference preparations was incorrect. Two of the three candidate reference reagents performed almost equally well and one of these reagents is recommended as the APTT reference preparation. Use of a single b value for a brand of reagent for all laboratories is not advised. Each laboratory must perform its own local calibration. The adoption of a reference APTT reagent together with the use of orthogonal regression analysis would be a useful step to initiate APTT heparin monitoring standardization and to develop safe and effective local therapeutic ranges.


Talanta ◽  
2017 ◽  
Vol 162 ◽  
pp. 567-573 ◽  
Author(s):  
Fernanda Pavani Stamm Maldaner ◽  
Rafaela Ferreira Perobelli ◽  
Bruna Xavier ◽  
Gabriel Lunardi Remuzzi ◽  
Maurício Elesbão Walter ◽  
...  

1990 ◽  
Vol 64 (02) ◽  
pp. 267-269 ◽  
Author(s):  
A B Heath ◽  
P J Gaffney

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.


1998 ◽  
Vol 79 (02) ◽  
pp. 439-443 ◽  
Author(s):  
Veena Chantarangkul ◽  
Barbara Negri ◽  
Marigrazia Clerici ◽  
Pier Mannuccio Mannucci ◽  
Armando Tripodi

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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