Disease relevance of Radioligand Assay

• A radioreceptor assay for serum 1,25-dihydroxyvitamin D (calcitriol) was used to screen patients with hypercalcemia of malignancy [1].
• The antibodies were competent for neutralizing the biological activity of HCG in the mouse uterine weight gain assay, the ventral prostate weight gain assay, and the radioligand assay for binding of 125I-labeled HCG to receptors on corpus luteum [2].
• A tumor-associated epidermal growth factor (EGF)-like activity was detected in the urine of breast cancer patients by means of an EGF radioreceptor assay and an anchorage-independent growth assay [3].
• Fine needle aspiration provides a homogeneous suspension (about 90% malignant cells) with a sufficient amount of cellular material (10 to 50 micrograms DNA per sample) for single point radioligand assays of extractable estrogen (ER) and/or progesterone receptor (PR) in about 85% of primary adenocarcinomas at the time of diagnosis [4].
• Plasma GABA-like activity (determined by radioreceptor assay) and plasma GABA and taurine concentrations (determined by high-performance liquid chromatography) were measured in 18 rats with acute or chronic hepatic encephalopathy and 9 control rats [5].

Psychiatry related information on Radioligand Assay

• The authors found higher levels of CSF opioid activity, determined by radioreceptor assay, in patients with anorexia nervosa who were severely underweight than in 1) the same patients after weight restoration and 2) normal controls [6].

High impact information on Radioligand Assay

• We measured the concentration of VEGF in 210 specimens of ocular fluid obtained from 164 patients undergoing intraocular surgery, using both radioimmuno-assays and radioreceptor assays [7].
• To investigate whether somatotroph sensitivity to GRF is modulated at its receptor level, we have developed a radioreceptor assay using an iodinated analogue of hGRF as radioligand [8].
• This cDNA, which was cloned in the Okayama-Berg expression vector, specifies the synthesis of biologically active CSF-1 in COS cells, as determined by a specific radioreceptor assay, macrophage bone marrow colony formation, and antibody neutralization [9].
• A new radioreceptor assay was used to quantify changes in serum concentration of 1alpha,25-dihydroxyvitamin D3 in rats with low calcium or low phosphate diets [10].
• Secreted TGF-beta activity was quantified by use of an 125I-TGF-beta competitive radioreceptor assay [11].

Chemical compound and disease context of Radioligand Assay

• Specific binding of angiotensin II to isolated granuloma macrophages was demonstrated by both fluorescence and radioligand assays [12].
• The relationship between thyroid-stimulating immunoglobulins, measured by both radioreceptor assay and adenylate cyclase stimulation, and the HLA alleles was studied in 41 patients with Hashimoto's thyroiditis [13].
• Using a radioreceptor assay and serum immunoglobulin (Ig) prepared by ammonium sulfate precipitation, significant TSH displacement activity (TDA) was demonstrated in 5 of 15 patients with subacute thyroiditis tested during the acute phase [14].
• The authors studied the pharmacokinetic properties of this drug in normal volunteers and patients with Cushing's syndrome using a rat progesterone radioreceptor assay [15].
• 1. Alterations in the levels of intracellular calcium ([Ca2+]i) and D-myo-inositol-1,4,5-trisphosphate (InsP3) were measured in the murine neuroblastoma cell line clone, N1E-115, by use of the calcium-sensitive dye, fura-2 and a radioreceptor assay, respectively [16].

Biological context of Radioligand Assay

• Using a sensitive radioreceptor assay for anticholinergic drugs, we assayed trihexyphenidyl in human serum and studied its pharmacokinetics following short-term and long-term administration to patients with dystonia [17].
• This material cross-reacted with a monoclonal antibody to hr-bFGF, comigrated with hr-bFGF by Western blot analysis, competed with 125I-hr-bFGF in a radioreceptor assay, and stimulated SNB-19 cell growth [18].
• The analysis of the properties of equine gonadotropins in homologous and heterologous radioreceptor assays suggests that all glycoprotein hormones share a common high affinity binding site and that specificity of binding is due to binding prohibition sites preventing fixation of each hormone to the receptors of the other glycoprotein hormones [19].
• The biological activities of these hGH analogs were tested in vitro by a radioreceptor assay and an assay to test the ability of the molecules to induce tyrosine phosphorylation of a 93-kDa protein in a human lymphocyte line, IM-9 [20].
• In acini prelabeled with [3H]inositol, PI hydrolysis on stimulation with either cholecystokinin or carbachol was inhibited dose-dependently by U73122, with a maximal effect seen at 10 microM; the formation of inositol 1,4,5-trisphosphate, measured using a radioreceptor assay, was also similarly inhibited [21].

Anatomical context of Radioligand Assay

• Results from a radioreceptor assay indicate that the quantity of EGF in the serum of fetuses removed from control rats on day 21 is twofold greater than the quantity in serum of fetuses from diabetic rats [22].
• Thyroid-stimulating immunoglobulins (TSIs) were measured by radioreceptor assay in serum from 51 patients with a multinodular goitre, divided into four groups according to thyroid function, and in 30 normal people [23].
• Extracts from an acetone powder preparation of a culture of a microorganism tentatively named Progenitor cryptocides contain choriogonadotropin (CG)-like factor as determined by radioimmunoassay with antiserum to human (h)CG beta subunit COOH-terminal peptide and radioreceptor assay with bovine corpus luteum membranes [24].
• A radioreceptor assay utilizing human fetal brain plasma membrane as matrix and somatomedin A as ligand (fetal brain RRA-SMA) was developed [25].
• Levels of PDGF competitor in conditioned medium at the end of a 48-hr collection were as high as 2 ng/ml--high enough to be measured by radioreceptor assay diluted 1:30 and to maximally stimulate [3H]thymidine incorporation by human fibroblasts [26].

Associations of Radioligand Assay with chemical compounds

• The number of sodium channels was assessed with a radioligand assay using the sodium channel-specific toxin [3H]batrachotoxinin benzoate ([3H]BTXB) [27].
• All three cell types expressed alpha 3 beta 1 but this integrin did not bind to collagen--Sepharose or to immobilized collagen type I in a radioreceptor assay [28].
• A rapid and sensitive radioreceptor assay for benzodiazepine in plasma [29].
• High correlations (r = 0.98; P less than .001) were obtained between the "diazepam equivalents" measured in plasma with the radioreceptor assay and the levels of diazepam and nordiazepam obtained by gas-liquid chromatography [29].
• MEASUREMENTS: Serum total 25-hydroxyvitamin D (25-OHD) and 1,25-(OH)2D levels were measured by radioreceptor assays [30].

Gene context of Radioligand Assay

• Using radioreceptor assays, we could demonstrate significant concentrations of insulinlike growth factor (IGF)-1 (300 ng/10(6) cells x 48 hours) and quite lower concentrations of bFGF and TGF-alpha in the hepatocyte-conditioned media (PCcM), whereas IGF-2 was not detectable [31].
• Medium conditioned by BON cells had detectable TGF beta activity, although most of the activity was latent as determined by radioreceptor assay with and without prior acid treatment [32].
• Western blots and radioreceptor assay of Con8-secreted proteins revealed that glucocorticoids inhibited the production of a M(r) 5500 immunoreactive TGF-alpha protein by 10-fold [33].
• In addition, using a radioreceptor assay, we have shown that phosphorothioate homopolymers of cytidine and thymidine blocked binding of not only 125I-bFGF, but also of 125I-PDGF to NIH 3T3 cells, whereas phosphodiester oligodeoxynucleotides were ineffective [34].
• Expression of CGRP receptors (CGRPRs) and VIP receptors (VIPRs) on RA synovial cells was assessed by RT-PCR and radioreceptor assays [35].

Analytical, diagnostic and therapeutic context of Radioligand Assay

• It appeared to be identical to the high-molecular weight hEGF/UG previously reported in human urine, except for its apparently equal activities in radioimmunoassay and radioreceptor assay [36].
• Plasma GABA-like activity (determined by radioreceptor assay) and true plasma GABA concentrations (determined by high-performance liquid chromatography) were found to be significantly increased in both portal vein-ligated and portal vein and bile duct-ligated rats, compared with controls [37].
• Northern blotting showed the expression of EGF receptor mRNA in all 10 cell lines that were found to be EGF receptor-positive and in one cell line that was found to be EGF receptor-negative in the radioreceptor assay and affinity labeling [38].
• Although measurement of IL-1 activity by bioassay suggested that dBcAMP and PGE2 could suppress LPS-induced IL-1 expression, levels of IL-1 protein, determined by radioreceptor assay, were markedly elevated. cAMP did not appreciably alter the stability of either IL-1 alpha or IL-1 beta mRNA [39].
• An immunoprecipitation radioligand assay was used to detect anti-GAD65 autoantibodies with in vitro transcribed and translated human islet GAD65 as antigen [40].

References