Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0338671 (Steroids)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A sensitive and simple enzyme immunoassay for direct quantitation of serum dexamethasone was established. An antiserum with high specificity was produced by the immunization of rabbits with a newly synthesized 4-(carboxymethylthio)dexamethasone-bovine serum albumin conjugate. Alkaline phosphatase was used as a labeling enzyme. The minimum amount of dexamethasone detected was 2 pg per tube on the basis of B/Bo 100 - 2 SD (%) of standard curve. However, taking into account the cross-reaction with steroids such as cortisol in dexamethasone-free serum, the measurable range was from approximately 0.13 to 10 micrograms/dl. Intra- and interassay coefficients of variation were 1.5 - 5.4% and 0.6 - 6.5%, respectively. Serum levels of dexamethasone and cortisol in four normal subjects after an oral administration of 1 mg of dexamethasone are also reported.
Steroids 1992 Apr
PMID:Enzyme immunoassay for serum dexamethasone using 4-(carboxymethylthio)dexamethasone as a new hapten. 151 61

A rapid, convenient, and specific radioimmunoassay for 5 beta-cholestane-3 alpha,7 alpha,12 alpha,25-tetrol has been developed. Specific antiserum was obtained from rabbits immunized by the bile alcohol-bovine serum albumin conjugate, which was coupled by an (O-carboxymethyl)oxime bridge at the C-3 position. The assay produces values for serum concentrations of bile alcohol glucuronides in patients with cerebrotendinous xanthomatosis.
Steroids 1992 Jan
PMID:Radioimmunoassay of 5 beta-cholestane-3 alpha,7 alpha,12 alpha,25-tetrol 3-glucuronide in serum of patients with cerebrotendinous xanthomatosis. 158 91

Three antisera raised against bovine serum albumin (BSA) conjugates of testosterone-3-(O-carboxy-methyl)-oxime (T-3-CMO), 11 beta-hydroxytestosterone-11-carboxymethyl ether (T-11 beta-O-CME) and 19-hydroxytestosterone-19-carboxymethyl-ether (T-19-O-CME) were evaluated in enzyme immunoassays (EIAs) in combinations with penicillinase-labeled T-3-CMO, T-11 beta-O-CME, T-19-O-CME, and testosterone-17 beta-hemisuccinate (T-17 beta-HS) for their influence on the sensitivity and specificity of EIAs. Of the various combinations, anti-T-3-CMO antiserum along with T-11 beta-O-CME-penicillinase showed no cross-reaction with any of the closely related steroids, although the same antibody had 21.6% binding to 5 alpha-dihydrotestosterone (5 alpha-DHT) in radioimmunoassay. All the homologous combinations appeared to be less sensitive due to their low affinity for testosterone. It was also apparent that of all the heterologous systems tested, only two combinations, (a) anti-T-19-O-CME antiserum and T-3-CMO-penicillinase and (b) anti-T-3-CMO antiserum and T-11 beta-O-CME-penicillinase, were found to be more sensitive. The former was less specific; it showed 70% cross-reaction with 5 alpha-DHT. The ability of testosterone to displace the hapten-enzyme conjugate and the specificity of the assay appear to depend on the position of the enzyme label on the steroid molecule as well as on the availability of antigenic sites in particular combinations of antibody and hapten-enzyme conjugates.
Steroids 1992 Mar
PMID:Influence of different combinations of antibodies and penicillinase-labeled testosterone derivatives on sensitivity and specificity of immunoassays. 162 Dec 65

A radioimmunoassay for measuring 3 alpha-hydroxy-5 alpha-pregnan-20-one in plasma has been developed. Polyclonal antibodies were raised in rabbits against 3 alpha-hydroxy-20-oxo-5 alpha-pregnan-11 alpha-yl carboxymethyl ether coupled to bovine serum albumin. 3 alpha-Hydroxy-5 alpha-pregnan-20-one was purified from either extracts of plasma by high-performance liquid chromatography. These antibodies were then used for the radioimmunoassay of this centrally active progesterone metabolite in rat and human plasma. 3 alpha-Hydroxy-5 alpha-pregnan-20-one was detected in plasma from female rats on the day of estrus (2.0 to 9.3 ng/ml) and in the plasma of women during the luteal phase of the menstrual cycle at levels ranging from 0.25 to 2.5 ng/ml. The latter was highly correlated with plasma progesterone levels.
Steroids 1990 Jul
PMID:Radioimmunoassay of 3 alpha-hydroxy-5 alpha-pregnan-20-one in rat and human plasma. 212 Aug 1

To determine the effects of serum proteins on the biologic activity of estrogens, we perfused isolated livers from ovariectomized female rats with oxygenated Krebs-Henseleit-bicarbonate buffer (KHBB), with and without 4% human serum albumin (4% HSA), with and without added estrogens, or with charcoal-stripped human serum (CSHS) with and without added estradiol. At the end of the perfusions, the cytosolic and nuclear estrogen receptors were measured by an exchange assay. When added to KHBB, estradiol 10(-9) or 10(-8) M or estrone 10(-8) M did not cause any significant increase in the percent of receptors measured in the nucleus. When the livers were perfused with KHBB containing 4% HSA and estradiol 10(-9) to 10(-7) M or estrone 10(-8) M, there was an increase in nuclear receptors. Perfusion with estradiol 10(-8) M in CSHS resulted in significantly less receptor in the nucleus than after estradiol in KHBB plus 4% HSA. We conclude that the presence of 4% HSA in the perfusion medium increases the biologic activity of estradiol and estrone on the isolated rat liver, and this increase is inhibited in the presence of sex hormone-binding globulin. The exact mechanism by which HSA increases the biologic activity is uncertain, but may be due in part to better diffusion of estrogen through the liver.
Steroids 1990 Jan
PMID:Effects of serum proteins on estrogen action in the perfused rat liver. 230 57

For radioimmunoassay of the catechol estrogens, four hapten-bovine serum albumin (BSA) conjugates were prepared from 6-oxo-2-hydroxyestradiol 6-(O-carboxymethyl)oxime, 2-hydroxyestradiol 17-hemisuccinate, 6-oxo-4-hydroxyestradiol 6-(O-carboxymethyl)oxime and 4-hydroxyestradiol 17-hemisuccinate by coupling with BSA, employing the mixed anhydride method. The antisera elicited in rabbits by immunization with these antigens showed high affinity and specificity for 2-hydroxyestradiol or 4-hydroxyestradiol with cross-reactivities to a few structurally related estrogens. The specificity of antisera obtained is discussed in relation to the site of attachment of the hapten to BSA.
Steroids
PMID:Characterization of antisera to 2-hydroxyestradiol and 4-hydroxyestradiol using 6-(O-carboxymethyl)oxime- and 17-hemisuccinate-bovine serum albumin conjugates and radioimmunoassay. 242 37

Production of monoclonal antibodies (MABs) to a 17 alpha-ethynyl-1,3,5 (10)-estratriene-3,17 beta-diol (ethynylestradiol, EE2) hapten is described. Culture antibodies generated by hybridized cells tested in enzyme-linked immunosorbent assay (ELISA) bound the 6-oxoethynyl-estradiol-6-(0-carboxymethyl) oxime-bovine serum albumin conjugate (EE2-6-0 CMO-BSA) but not BSA. On radioimmunoassay (RIA) with tritiated ethynylestradiol (3H-EE2), some of the antibodies demonstrated high binding affinity (Ka = 2.8 X 10(10) M-1) to EE2. Estradiol-17 beta, estrone and estriol did not show any displacement of 3H-EE2 from the MABs even at high concentration (1 X 10(4) ng/mL). Among the widely used progestins, norethynodrel and norethisterone exhibited considerable cross-reactivity (25.7-100% and 0.3-54.1%, respectively) but not levonor-gestrel with the MABs. The high affinity demonstrated by the MABs to EE2 3-sulfate but not to EE2 17-sulfate and EE2 3,17-disulfate suggests the dominant role of the 17 beta-hydroxyl group in immunogenicity.
Steroids
PMID:Development of a monoclonal antibody for use in radioimmunoassay of ethynylestradiol. 243 22

The effect of inhibition of estrogen synthesis on ovulation in rat ovaries perfused in vitro with medium without phenol red was examined. The addition of luteinizing hormone (LH, 0.1 microgram/mL) plus 3-isobutyl-1-methylxanthine (IBMX, 0.2 mM) to phenol red-free perfusion medium (M199 + 4% bovine serum albumin) induced ovulation. The number of ovulations was similar to that found in medium containing phenol red. There was a similar increase in estradiol (1, 3, 5 (10)-estratriene-3, 17 beta-diol) levels in the medium in both groups. The addition of 4-hydroxy-4-androstene-3, 17-dione (4-OH-A, 5 microM) to phenol red-free medium blocked the increase in estradiol levels induced by LH + IBMX, but did not prevent ovulation. There was no significant difference in the number of ovulations in the three groups. In conclusion, phenol red in the perfusion medium does not influence ovulation induced by LH + IBMX. Furthermore, an increase in estrogen is not required during the immediate preovulatory period for ovulation to occur.
Steroids
PMID:Ovulation in the perfused ovary in vitro: further evidence that estrogen is not required. 246 93

A radioimmunoassay for 3 beta-hydroxy-5-cholenoyl glycine in human urine has been developed. The antiserum was elicited with the antigen in which the steroid hapten is linked to a bovine serum albumin through the C-19 position. The [125I]-tyrosine derivative of the hapten was used as radioligand. The standard curves were linear ranging from 10 to 320 ng/mL. The cross-reactivities with other bile acids were not detectable and below 0.3% with cholesterol. Sample preparation includes extraction of 3 beta-hydroxy-5-cholenoyl glycine from urine and solvolysis of the sulfates--main form present in urine. Urinary excretion of 3 beta-hydroxy-5-cholenoyl glycine was 0.373 +/- 0.133 mumol/day in healthy adults. Urinary excretion of 3 beta-hydroxy-5-cholenoyl glycine increased in chronic liver dysfunction, hepatoma and obstructive jaundice in this order.
Steroids
PMID:Radioimmunoassay of urinary 3 beta-hydroxy-5-cholenoyl glycine in hepatobiliary disease. 303 57

The development of highly specific monoclonal antibodies to estriol and a nonisotopic immunoassay (EIA) for unconjugated estriol based on the use of these monoclonal antibodies have been described. The monoclonal antibodies show little cross reactivity with other steroids and steroid conjugates and can be used directly in immunoassays without any purification. The EIA described here can be performed in 96-well microtiter plates or polystyrene tubes that have been coated with estriol-bovine serum albumin conjugate. In this assay, estriol in the standard or clinical samples (serum or saliva) competes with the immobilized steroid on the plate or the tube for binding with the antibody. The assay shows good agreement with radioimmunoassay (RIA) and is highly sensitive and reliable. Since no prior processing or extraction of the clinical samples is necessary, the method is potentially applicable for routine use in fetal monitoring as well as in a steroid laboratory.
Steroids
PMID:Production of monoclonal antibodies to estriol and their application in the development of a sensitive nonisotopic immunoassay. 307 43


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