Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We measured parathyrin (parathyroid hormone)-related peptide (PTHRP) in plasma by three region-specific RIAs and compared them with an established two-site immunoradiometric assay (IRMA) of PTHRP1-86 in samples from control subjects and from patients with primary hyperparathyroidism (PH) and humoral hypercalcemia of malignancy (HHM). The two direct RIAs of PTHRP1-34 and PTHRP37-67 were specific for regions 9-18 and 52-61, respectively. In the extraction RIA of PTHRP1-34 we used an affinity gel containing a monoclonal antibody specific for the 17-27 sequence; cross-reacting PTHRP species eluted from the gel were assayed by the RIA of PTHRP1-34. PTHRP1-86 plasma concentrations by IRMA were less than 0.23 pmol/L in control subjects and patients with PH, and were significantly increased in patients with HHM (mean 6.1 pmol/L, P less than 0.001). In contrast, plasma PTHRP1-34 concentrations were not significantly different in the three groups; in HHM patients, the mean was 190 pmol/L. Plasma PTHRP37-67 concentrations were similar in control and PH groups and, although significantly increased in HHM patients (mean 440 pmol/L, P less than 0.002), showed poor diagnostic discrimination. PTHRP1-34 concentrations after affinity extraction of plasma were also significantly higher in HHM patients (mean 10.7 pmol/L, P less than 0.001), but showed incomplete diagnostic discrimination. We conclude that the diagnostic utility of the direct RIAs for quantifying PTHRP is markedly inferior to the IRMA of PTHRP1-86.
 ...
PMID:Immunoreactivity of plasma parathyrin-related peptide: three region-specific radioimmunoassays and a two-site immunoradiometric assay compared. 184 54

This two-site immunoradiometric assay for human parathyrin-related protein 1-86 (PTHRP1-86) in plasma uses a mouse monoclonal antibody to PTHRP1-34 coupled to cellulose particles for immunoextraction of N-terminal immunoreactivity, and a rabbit antiserum to PTHRP37-67 that is indirectly labeled with 125I-labeled PTHRP37-67 for quantifying the bound analyte. The detection limit of the assay is 0.23 pmol/L, corresponding to 0.4 pg (0.04 fmol) per tube, for a sample volume of 200 microL. Recovery of PTHRP1-86 added to serum is essentially quantitative, and within- and between-batch precision is 4.4% and 11.1%, respectively. PTH1-84, PTHRP18-34, PTHRP9-34, PTHRP1-34, and PTHRP37-67 do not cross-react in the assay at concentrations up to 2 nmol/L. Plasma concentrations of PTHRP1-86 were below or close to the detection limit of the assay in normal subjects and in patients with primary hyperparathyroidism, hypoparathyroidism, chronic renal failure, and normocalcemic malignancy. In 37 hypercalcemic patients with various malignancies, we found detectable PTHRP1-86 concentrations in 35 (95%, mean 7.4 pmol/L, range 0.46-24.7). The data support the proposed humoral role of PTHRP in cancer-associated hypercalcemia and suggest that the assay has clinical utility in the differential diagnosis of hypercalcemia.
 ...
PMID:Development and validation of an immunoradiometric assay of parathyrin-related protein in unextracted plasma. 203 20