A Sensitive Radioimmunoassay of Parathyroid Hormone in Human Serum Using a Specific Extraction Procedure

1976 ◽  
Vol 36 (4) ◽  
pp. 313-322 ◽  
Author(s):  
Merete Sanvig Christensen
1975 ◽  
Vol 80 (1_Suppla) ◽  
pp. S130 ◽  
Author(s):  
H. Wagner ◽  
V. Maier ◽  
H.-J. Herrmann ◽  
H. E. Franz

1981 ◽  
Vol 96 (2) ◽  
pp. 215-221 ◽  
Author(s):  
L. E. Mallette

Abstract. An antiserum (NG-1) against bovine PTH (bPTH) generated in the domestic goat was characterized for use in the radioimmunoassay of PTH in human serum. When a carboxyterminal fragment of bPTH is used as radioligand, this antiserum detects only an antigenic site in the central region of the hPTH molecule. The synthetic hormone fragment, hPTH-(44-68), will displace 93% of the tracer, after which the addition of intact hPTH causes no further displacement. The assay does not detect the synthetic aminoterminal 1-34 fragment of the bovine or human hormones, nor the carboxyterminal fragment of the human hormone, hPTh-(53-84). Standard curves with bPTH-(1-84) and partially purified hPTH are not parallel, so that hPTH is used as standard. Serum from subjects with uraemia or primary hyperparathyroidism gives dilution curves parallel to that with the hPTH standard. The assay with NG-1 has been applied to the diagnosis of primary and secondary hyperparathyroidism, used to monitor the disappearance of PTH after parathyroidectomy, and for measurement of PTH in selective venous samples.


1975 ◽  
Vol 80 (1) ◽  
pp. 58-69 ◽  
Author(s):  
A. Burger ◽  
C. Sakoloff ◽  
V. Staeheli ◽  
M. B. Vallotton ◽  
S. H. Ingbar

ABSTRACT Two radioimmunoassays for triiodothyronine (T3) are described, one of which includes an extraction step, while the other does not. To raise antibodies, two carrier proteins and different coupling agents were used, namely haemocyanin and diazotized benzidine or human serum albumin and carbodiimide. In the case of T3 coupled to haemocyanin by diazotized benzidine, evidence of covalent binding of the hapten to the protein was obtained. In the case of T3 coupled to human serum albumin, little evidence of covalent linkage was available. Nevertheless immunization was successful in both cases. The radioimmunoassay in unextracted serum was highly reproducible and precise (intra-assay variability 5.2% inter-assay variability 8.1%). Normal values were determined which clearly indicate a fall in the serum T3 concentration with increasing age. In men the fall occurs in the fifth decade. In women the T3 starts to fall only after 70 years of age. In 31 cases of hyperthyroidism the serum T3 concentration ranged from 2.26 to 10.4 ng T3/ml. In 10 cases of hypothyroidism the values ranged from 0 to 0.8 ng T3/ml. The radioimmunoassay using an extraction procedure was less extensively used since it was found to be less reproducible (intra-assay variability 7.5%, inter-assay 12.25%). The normal values were determined with a mixed population aged 20–50. The mean ± 2 sd was 0.9 ± 0.36 ng T3/ml (n=52). In 17 cases of hypothyroidism the values ranged from 0 to 0.6 ng T3/ml and in 22 cases of hyperthyroidism from 2 to 14.4 ng T3/ml.


2021 ◽  
Vol 18 (4) ◽  
pp. 79-86
Author(s):  
Divya Kottadiyil ◽  
Shital Deore ◽  
P. Sivaperumal

In recent years, exposure to pesticides has gained widespread attention due to their adverse health effects. Long-term exposure to pesticides has shown hazardous effects on vital functions of the human nervous and reproductive systems. Therefore, it is crucial to determine the extent of pesticide exposure in humans. Primarily, it is quite challenging to determine trace levels of pesticide residues in biological matrices. Hence, a quick, multi-residue extraction procedure was experimented for pesticide residue analysis in human serum. Herein, the original QuEChERS extraction method was modified for achieving the best possible recoveries. A total of 15 representative pesticides from each class were selected and fortified into the human serum samples. The extraction was performed by employing acidified solution containing acetonitrile and ethyl acetate followed by vortex and centrifugation. The obtained aqueous layer was collected and vapourised to dryness and d-SPE clean-up was conducted utilising PSA. The extracted sample was injected into the GC-MS/MS system under MRM mode. The method development parameters such as linearity, % RSD, accuracy, LOD, LOQ and % ME were assessed. The results obtained for the serum matrix were found to be within the criteria mentioned in European Union SANTE/12682/2019 guidelines for method validation. The developed solitary method is quick, simple and highly efficient for routine pesticide residue analysis. Hence, a wide spectrum of pesticides can be analysed utilising the proposed method for human serum.


2019 ◽  
Vol 128 ◽  
pp. 165-174 ◽  
Author(s):  
Ajay Kumar Yagati ◽  
Anna Go ◽  
Sachin Ganpat Chavan ◽  
Changyoon Baek ◽  
Min-Ho Lee ◽  
...  

1977 ◽  
Vol 23 (5) ◽  
pp. 806-810 ◽  
Author(s):  
R S Mason ◽  
S Posen

Abstract Methods available for the assay of 25-hydroxycalciferol in human serum are evaluated and compared to one another. Ethanol was chosen for use in the initial extraction procedure and rat-kidney cytosol as the binding protein, although good alternative methods are also available. We used silicic acid for chromatography and found this an essential step. Reproducibility was increased when, after "bound" and "free" material were separated, an aliquot of the supernate was pipetted into the counting vial instead of the entire supernatant fluid being decanted. Beta-lipo-protein added to the assay system was of no advantage; added bovine serum albumin interfered with the assay by giving rise to high blank values. With ethanol extraction, silicic acid chromatography, rat kidney cytosol and separation on dextran-coated charcoal, sera from normal subjects showed a mean 25-hydroxycalciferol concentration of 28.5 microng/liter (range, 13.1 to 43.9) during the fall season. Coefficients of variation for a control serum were 4.9% (intra-assay) and 10.9% (interassay).


Author(s):  
J. S. Woodhead ◽  
D. A. Walker

The assay of parathyroid hormone has contributed greatly to our understanding of calcium metabolism in health and disease. The most important clinical application of the assay is in the differential diagnosis of hypercalcaemia, which is an increasing clinical problem. PTH assays are of little or no value in the absence of other biochemical data, especially accurate determinations of plasma calcium and phosphate.


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