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Query: UMLS:C0338671 (Steroids)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dehydroepiandrosterone, testosterone and progesterone 7-carboxymethyl derivatives were prepared: 7 alpha and 7 beta epimers were separated and coupled to bovine serum albumin. Preliminary studies of the antisera induced by these antigens showed that they have high affinity and good specificity.
Steroids 1980 Mar
PMID:Preparation of dehydroepiandrosterone, testosterone and progesterone antigens through 7-carboxymethyl derivatives: characteristics of the antisera to testosterone and progesterone. 644 11

Antisera were raised in male guinea pigs against 6-oxoestriol 3-sulfate O-carboxymethyloxime-bovine serum albumin (BSA) conjugate. The antisera to this antigen exhibited high affinity (Ka=4.7 X 10(9)M-1) and excellent specificity for estriol 3-sulfate, showing slight cross-reactions (less than 0.43%) with other estrogen sulfates, and no cross-reactivities with free estrogens and other steroids (less than 0.01%) except cholesterol sulfate (0.22%). A standard curve using [6, 7-3H]-estriol 3-sulfate as the radioactive ligand showed high sensitivity in the range of 10-1000 pg estriol 3-sulfate.
Steroids 1984 Mar
PMID:Specific antisera for the radioimmunoassay of estriol 3-sulfate. 652 41

Both the validity and practicability of a direct progesterone radioimmunoassay based on radioiodinated progesterone tracers were studied. The results obtained show the reliability of the assay; when compared with assays based on 3H-progesterone tracers there are fewer steps for assay execution, saving time and reducing the number of reagents used. Various commercially available 125I-progesterone tracers were assayed, and only those with an 11 alpha-hemisuccinate bridge were suitably bound by antisera raised against progesterone-bovine serum albumin conjugates having identical bridge structure. The bridge effect caused no observable alteration in validity parameters. Finally, our results support the utility of this assay as a practical method of early diagnosis of pregnancy and as a reliable experimental technique to monitor cow ovarian function.
Steroids 1984 Sep
PMID:Milk progesterone radioimmunoassay using radioiodinated tracers: a rapid and reliable assay system. 653 52

In order to characterize from a kinetic viewpoint the antibody population mainly involved in the binding of testosterone by its homologous antiserum, the kinetics of the association reaction between [1,2,6,7-3H]-testosterone and rabbit antiserum anti-testosterone-3-(O-carboxymethyl)oxime-bovine serum albumin (Ab R2603-1) was followed at pH 7.4 and at constant ionic strength, at temperatures ranging from 2 degrees C to 37 degrees C and at concentration near to work conditions for testosterone radioimmunoassay; dextran coated charcoal suspension was used for the bound/free separation. In the examined concentration range, the observed kinetics trends can be explained by assuming the existence of two classes of antibody binding sites, Ab1 and Ab2. The kinetics of the dissociation reaction of the testosterone-antibody complex was also followed after the addition of a large excess of unlabeled testosterone. At 22.0 degrees C, association and dissociation rate constants are 2.1.10(7) s-1M-1 and 3.7.10(-3) s-1, respectively, for the Ab1 class of antibody binding sites, and 3.6.10(6) s-1M-1 and 7.0.10(-4) s-1 for the Ab2 class. Equilibrium constants obtained from kinetic data were very similar for both classes of antibody binding sites and in good agreement with the equilibrium values obtained from linear Scatchard plot. The order of magnitude of the second order rate constants and the high activation enthalpy for the forward and reverse reaction suggest a mechanism more complex than a simple second order.
Steroids 1983 Nov
PMID:Kinetics of the reaction between testosterone and antitestosterone antiserum. 668 Sep 25

Rat skeletal muscle cytosol proteins bound 3H-diethylstilbestrol (3H-DES). More than 90% of this binding was high capacity and low affinity. Serum albumin accounted for roughly 50-60% of the binding, as evidenced by its precipitation with anti-rat albumin IgG. About half of the binding was distinguishable from albumin and other serum proteins by its precipitation in 40% saturated ammonium sulfate. This material sedimented at 4-5S in high-salt sucrose gradients, and resolved into two components (8S and 4-5S) in low-salt. Following incubation at 23-27 degree C for one hour, 2% of the bound 3H-DES in whole cytosol (approximately 2 fmole/Mg cytosol protein) was retained by DNA cellulose, and was eluted with 0.6 M KCl. This small fraction of the total binding was inhibited by estrogens and DES analogues: estradiol-17 beta, DES, dienestrol, and hexestrol were strong inhibitors; isodienestrol, dimethylstilbestrol, estradiol-17 alpha, estrone, tamoxifen, MER-25, CI-628, and nafoxidine were weak inhibitors; dihydrotestosterone, testosterone, and prednisone did not compete. These observations indicate that specific estrogen-binding sites exist in rat skeletal muscle.
Steroids 1982 May
PMID:Specific cytosol binding of diethylstilbestrol in rat skeletal muscle. 675 12

Exposure of guinea pig liver microsomes to phospholipase A2 resulted in the nearly complete loss of 17 beta-hydroxysteroid oxidoreductase (17 beta-HSD) activity, the time course of which correlated with phospholipid hydrolysis and lysolecithin formation. Lysolecithin and unsaturated fatty acids added to microsomes also inactivated 17 beta-HSD indicating that they may contribute to the inactivation by phospholipase A2. If exposure to lysolecithin and fatty acids was minimized by including serum albumin in the reaction mixture, phospholipids were rapidly hydrolyzed; but in this case the extent of 17 beta-HSD inactivation was less and the rate of loss was significantly slower. The data suggest that phospholipid hydrolysis per se results in a destabilization of 17 beta-HSD resulting in the subsequent activity loss. The inactivation of 17 beta-HSD by lysolecithin and fatty acids has not been reported previously and is suggestive of a possible control mechanism in vivo.
Steroids 1980 Jul
PMID:Phospholipase A2 inactivation of microsomal 17 beta-hydroxysteroid oxidoreductase: rates of phospholipid hydrolysis and enzyme inactivation, effects of hydrolysis products and properties of the phospholipase A2-treated enzyme. 693 6

A fluorimetric enzymeimmunoassay has been developed having the sensitivity (500 fg/assay tube) required for determining testosterone concentrations in female plasma and saliva samples. The assay featured a solid-phase antiserum raised against an 11 alpha-hydroxytestosterone-11-hemisuccinate bovine serum albumin conjugate, an 11 alpha-hydroxytestosterone-11-hemisuccinate horseradish peroxidase conjugate as the "enzyme label", and p-hydroxyphenylacetic acid as the substrate for the development of fluorescence. Specificity was ensured by "extracting" testosterone from samples with a solid-phase anti testosterone-3-/0-carboxymethyl/-oxime serum. The assay was shown to satisfy accepted validation criteria providing results in good agreement with routine radioimmunoassay procedures in both plasma (r greater than 0.98, n=28) and saliva (r greater than 0.99, n=28). In saliva samples collected at 2 hourly intervals by normal healthy women (n=5) testosterone concentrations showed a well defined circadian rhythm: the mean testosterone concentration in early morning samples (174 pmol/litre) fell by 83% in late evening collections. In healthy female volunteers (n=7), mean daily throughout one complete cycle ranged from 50 to 218 pmol/litre. Following dexamethasone administration testosterone concentrations in plasma fell by approximately 50%, and salivary concentrations were undetectable after one hour. This enzymeimmunoassay may be useful in studies of female infertility.
Steroids 1980 Jan
PMID:A sensitive enzymeimmunoassay with a fluorimetric end-point for the determination of testosterone in female plasma and saliva. 699 May 57

This paper reports the development of a solid-phase enzymeimmunoassay for quantitating levels of norethisterone (norethindrone) in small portions of plasma (10 mcliters) and saliva (100 mcliters). The assay system uses an antiserum against norethisterone-11 alpha-hemisuccinyl/bovine serum albumin conjugate, prepared by coupling to cyanogen bromide-activated cellulose. Enzyme label was norethisterone/horseradish peroxidase conjugate. The assay's sensitivity at its lower limit was 3 pg/tube. When these enzyme immunoassay results were compared with a standard radioimmunoassay, good agreement for both plasma (r=.99) and saliva (r=.98) was found. Healthy volunteers were then given a norethisterone-containing contraceptive orally, and their plasma and saliva levels of the agent were measured. The plasma and salivary values both peaked at 1 hour postadministration. Maximum salivary levels were but 3% of plasma levels; however, since they reflected, in ratio, concentrations in plasma, salivary measurements may prove useful in fertility control programs and pharamacokinetic studies.
Steroids 1980 Apr
PMID:A sensitive solid phase enzymeimmunoassay for norethisterone (norethindrone) in saliva and plasma. 699 May 58

A rapid, sensitive and highly specific radioimmunoassay (RIA) for 11-deoxycortisol has been developed and used for the measurement of serum concentrations. Antisera were raised using 11-deoxycortisol -3-carboxymethyloxime-bovine serum albumin as immunogen and showed minimal cross reaction with related steroids. 11-Deoxycortisol-3-carboxymethyloxime was coupled to 125 I-iodohistamine to produce a labelled antigen of high specific activity (s.a. 680 Ci/mmol). The assay was performed for 1h at room temperature and pH 4. Results were correlated with those after extraction, high pressure liquid chromatography and RIA of serum samples (y= 0.78x + 36.9; r = 0.97, p less than 0.001). The accuracy of the method was satisfactory (y = 1.00x - 0.61; r= 0.95; p less than 0.001). Assay sensitivity was 0.3 nmol/l. 11-Deoxycortisol concentrations in normal subjects at 09.OOh were 26-46 nmol/l (37.2 +/- 5.7; x- +/- 1 S.D.). The assay should facilitate the investigation of patients with possible abnormalities of adrenocortical function.
Steroids 1982 Feb
PMID:A direct radioimmunoassay for 11-deoxycortisol. 707 84

The treatment of pulmonary aspiration of gastric contents remains largely empirical. The purpose of the present study was to evaluate the effect of methylprednisolone administration (30 mg/kg) on alveolar-capillary membrane permeability after pulmonary acid aspiration in dogs. Alveolar-capillary membrane permeability was assessed by several methods. Extravascular lung water volume (EVLW), extravasation of 125I-serum albumin (RISA) into lung parenchyma, and albumin leak into the alveolar spaces were measured. EVLW increased progressively from 5.5 +/- 0.6 to 20.0 +/- 2.3 ml/kg in Group I (Acid) and from 5.4 +/- 1.2 to 22.1 +/- 3.1 ml/kg in Group II (Acid + Steroids) over the 5 hours after acid injury. The ratio of Lung Extravascular RISA to Plasma RISA was 0.56 +/- 0.14 and 0.58 +/- 0.14 in Group I and Group II, respectively (normal = 0.19 +/- 0.06). The tracheal albumin to plasma albumin ratio remained near 1.0 from 2 hours to 5 hours post-aspiration in both groups. This study demonstrated that pulmonary acid injury resulted in a marked increase in alveolar-capillary permeability to albumin, smaller solutes, and water which was not ameliorated by the administration of methylprednisolone.
 ...
PMID:The effect of intravenous steroids on alveolar-capillary membrane permeability in pulmonary acid injury. 707 96


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