Measurement by radioimmunoassays

Human intestinal mucosa as weU as livei can peifomi this conversion (344,345). Desogestiel and 3-ketodesogestiel can be measured by radioimmunoassay or hplc (339,345). 

Mifepristone. After oral adininistration, peak plasma levels of mifepristone (84) (RU 486) are reached in 1 h and over 95% was bound to plasma proteins (351,352). The plasma half-life of RU 486 is approximately 24 h (352,353). In humans, monodemethylated (98), didemethylated (99) and alcohoHc nondemethylated (100) metaboHtes of RU 486 have been identified (351). These metaboHtes show some progestin-binding affinity, approximately five to ten times lower than that of RU 486 itself. RU 486 and its metaboHtes can be measured by radioimmunoassay and hplc (353,354). 

Human erythropoietin is a glycoprotein of 166 amino acids (molecular mass about 34 kDa). Its amount in plasma can be measured by radioimmunoassay. It is the major regulator of human erythropoiesis. Erythropoietin is synthesized mainly by the kidney and is released in response to hypoxia into the bloodstream, in which it travels to the bone marrow. There it interacts with progenitors of red blood cells via a specific receptor. The receptor is a transmembrane protein consisting of two different subunits and a number of domains. It is not a tyrosine kinase, but it stimulates the activities of specific... 

Table 9 lists various congenital disorders and the immunoassay methods recommended for their mass screening. Most of the substances listed in Table 9 have been measured by radioimmunoassay, but a nonisotopic immunoassay such as enzyme immunoassay is now recommended. Sections 7.1 and 7.2 describe examples of mass screening by enzyme immunoassay. 

LCAT in the rat appears to be produced by the liver (B48, Nil, Oil). Although there seems to be no direct evidence of production by the liver in man, the hepatic origin of LCAT is suggested by the marked reduction in LCAT activity associated with liver diseases (C23, S51) including viral hepatitis (B37, Til) and cirrhosis (B37, S2, S36). LCAT activity is also said to be reduced in uremia (Sll) and pancreatic carcinoma (S36). The concentration of LCAT in normal human plasma (measured by radioimmunoassay) is about 6 mg/liter (A8). 

Schwinn G, von zur Muhlen A, Warnecke U (1976) Effects of dexamethasone on thyrotrophin and prolactin plasma levels in rats. Acta Endocrinol (Copenh) 82(3) 486-91 Simpkins JW, Bruni JF, Mioduszewski RJ, Meites J (1976) Serum and pituitary TSH and response to TRH in developing male and female rats. Endocrinology 98(6) 1365-9 Utsumi M, TateiwaM, MakimuraH, Yamada A, Mori H, Kusaka T, Sakoda M,Baba S (1975) Diurnal variation of the human urinary TRH excretion measured by radioimmunoassay. Endocrinol Jpn 22(6) 509-16... 

P10. Price, P. A., Parthemore, J. G., and Deftos, L. J., New biochemical marker for bone formation Measurement by radioimmunoassay for GLA protein in the plasma of normal subjects and patients with bone disease. J. Clin. Invest. 66, 878-883 (1980). 

After isolation of the oocytes, the follicular fluid from each patient was pooled, and after isolating the contaminating cells from the follicular fluid, the fluid was stored at -70°C until IGF-I determination. IGF-I was measured by radioimmunoassay (Nichols Institute Diagnostics, San Juan Capistrano, CA, USA). 

Measured by radioimmunoassay and corticosteroid release from a suspension of isolated cells. Lower recoveries observed for small sample loading (1-5 /ttg). 

TSH levels in the patient s blood were also measured by radioimmunoassay. If pituitary function is normal, the patient s TSH levels will most likely be... 

TATI in either serum or urine is routinely measured by radioimmunoassay. However, other detection methods have... 

Insuhn is a protein hormone produced by the (5-ceUs of the islets of Langerhans in the pancreas. Insulin was the first protein hormone to be sequenced, the first substance to be measured by radioimmunoassay (RIA), and the first compound produced by recombinant DNA technology for practical use. It is an anaboUc hormone that stimulates the uptake of glucose into fat and muscle, promotes the conversion of glucose to glycogen or fat for storage, inhibits glucose production by the liver, stimulates protein synthesis, and inhibits protein brealcdown. 

The low concentrations of bile acids in urine have also been measured by radioimmunoassay. In one study, total cholic and chenodeoxycholic acid conjugates were measured after extraction and solvolysis to remove sulfate groups, giving a mean urinary excretion of 0.6 p.mol/24 hours for cholic acid and 1.2 p.mol/24 hours for chenodeoxycholic acid in normal subjects (S7). These estimates can be compared with values of 2.1 xmol/24 hours for conjugated cholic acid and 8.4 xmol/24 hours for sulfoglycolithocholic acid obtained for the urinary excretion of bile acids using commercially available radioimmunoassays (WIO). 

JD Robinson, BA Morris, GW Aheme, V Marks. Pharmacokinetics of a single dose of phenytoin in man measured by radioimmunoassay. Br J Clin Pharmacol 2 345, 1975. 

CE Cook, E Amerson, WK Poole, P Lesser, L O Tuama. Phenytoin and phenobarbital concentration in saliva and plasma measured by radioimmunoassay. Clin Pharmacol Ther 18 742, 1975. 

JW Paxton, B Whiting, KW Stephen. Phenytoin concentrations in mixed, parotid and submandibular saliva and serum measured by radioimmunoassay. Br J Chn Pharmacol 4 185, 1977. 

The possible presence of transfer protein inhibitors in cytosol may require the quantitation of transfer proteins by techniques that do not rely on traditional transfer assays. Teerlink et al. (1981) used a doubleantibody radioimmunoassay specific for the phosphatidylcholine transfer protein in rat liver. The assay was effective over a range of 4 to 50 ng of transfer protein. The levels of phosphatidylcholine transfer protein in three lines of Morris hepatomas was found to be in agreement when quantitated by radioimmunoassay (Teerlink et al., 1981) or immunoti-tration (Poorthuis et al., 1980). In normal liver cells, the amount of phosphatidylcholine transfer protein measured with a transfer activity assay was only about one-third of the same protein measured by radioimmunoassay. Apparently not all of the transfer protein with immuno-reactivity possesses transfer activity. Possibly, modulators of transfer activity are present in normal rat liver. 

Beckett, G. J., Dyson, E. H., Chapman, B. J., Templeton, A. J., and Hayes, J. D., Plasma glutathione S-transferase measurements by radioimmunoassay A sensitive index of hepatocellular damage in man. Clin. Chim. Acta 146, 11-19 (1985). 

This enzyme has been measured in a number of toxicology studies with hepatotoxins (Di Simplicio 1982 Beckett, Hunter, and Hayes 1986 Clarke et al. 1997 Kilty et al. 1998 van der Aar et al. 1998 Eaton and Bammier 1999 Coluccio et al. 2000 Giffen et al. 2002 Strelic et al. 2003 Awasthi 2006). However, it has yet to establish a place among the common enzyme measurements, possibly because of the short half-life (<90 minutes). Currently, alpha-GST may be measured by radioimmunoassay or enzyme immunoassays given the complexity of the GST enzyme family, it may be more successful if new assays can be developed (see Chapter 2). 

Tani, S., A. Ishikawa, H. Yamazaki, and Y. Kudo. 1987. Serum pepsinogen levels in normal and experimental peptic ulcer rats measured by radioimmunoassay. Chemical and Pharmaceutical Bulletin (Tokyo) 35 1515-1522. 

Johnston, S. D., and E. C. Mather. 1978. Canine plasma cortisol (hydroxycortisone) measured by radioimmunoassay clinical absence of diurnal variation and results of ACTH stimulation and dexamethasone suppression tests. American Journal of Veterinary Research 39 1766-1770. 

Cooper DS, Saxe VC, Meskell M, et al. Acute effects of propylthiouracil (PTU) on thyroidal iodide organification and peripheral iodothyronine deiodination correlation with serum PTU levels measured by radioimmunoassay. J Clin Endocrinol Metab 1982 54 101-107. 

Rio, P. Bazgar, S. Leng, M. Detection of N-hydroxy-2-acetylamino fluorene DNA adducts in rat liver measured by radioimmunoassay. Carcinogenesis (Lond), 3 225-8. 1982. 

Serum total triiodothyronine (TT ) was measured by radioimmunoassay with a normal range during pregnancy of 850-1750 pg/ml. 

Results are similar when one aggregates washed platelet suspensions with PGH2. Exogenous addition of the immediate substrate for the thromboxane synthetase bypasses the cyclooxygenase enzyme, but TxB2, measured by radioimmunoassay accumulates, and aggregation accompanies the accumulation [Figure 2]. 

Figures. Bovine somatotropin (BST) plasma levels, measured by radioimmunoassay in nanograms per milliliter, in dairy cattle injected with a control gel formula or the same gel formula containing a zinc salt of BST (ZnMBS). (Data from Mitchell, 1991.)...

Plasma Level of Norethisterone Measured by Radioimmunoassay and Gas Chromatography-Mass Fragmentography J. Steroid Biochem. 10(1) 121-122... 

Example Charters AC, Odel UD, Davidson WD, et al. Gastrin Immunochemical properties and measurement by radioimmunoassay. Surgery 66 0A- 10, 1969. 

PGFaot was measured by radioimmunoassay (Lindgren et al., 1974). Proteins were measured following the method of Lowry et al. (1951). 

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