RADIOIMMUNOASSAY FOR 2-METHOXYOESTRONE IN HUMAN PLASMA

1979 ◽  
Vol 91 (1) ◽  
pp. 158-166 ◽  
Author(s):  
Günter Emons ◽  
Peter Ball ◽  
Gertrud v. Postel ◽  
Rudolf Knuppen
Keyword(s):  
Human Plasma ◽  
Plasma Concentrations ◽  
Cross Reactivity ◽  
Elderly Men ◽  
Specific Antibodies ◽  
Assay Procedure ◽  
Menopausal Women ◽  
Bovine Serum Albumin Conjugate ◽  
Post Menopausal

ABSTRACT A bovine serum albumin conjugate of 2-methoxyoestrone was used for the preparation of highly specific antibodies in rabbits. Cross-reactivity for catecholoestrogens and monophenolic steroids was below 0.3 %. Only 2-methoxyoestradiol cross-reacted with 44 %. An assay procedure for the determination of unconjugated and conjugated 2-methoxyoestrone in human plasma is described. The following mean plasma concentrations (pg/ml) were found (unconjugated/conjugated): children 61/1130, young men 74/1320, elderly men 109/1260, cycling women 131/1040, post-menopausal women 102/1420, and pregnant women 3980/5850.

Human Prothrombin Activation: Determination of Plasma and Serum Levels of Prothrombin Fragment 3 by Radioimmunoassay

1979 ◽  
Author(s):  
Daniel Walz ◽  
Thomas Brown
Keyword(s):  
Blood Clotting ◽  
Factor Xa ◽  
Heart Association ◽  
Serum Levels ◽  
Cross Reactivity ◽  
Assay Procedure ◽  
A Chain ◽  
Prothrombin Activation ◽  
Theoretical Amount

Human prothrombin activation is unique in that, in addition to the release of fragment 1.2 (FI.2) from the NH-terminus of prothrombin by factor Xa during the generation of thrombin, an additional 13 residue polypeptide, fragment 3 (F3), is autocatalytically removed from the amino-terminus of the thrombin A chain. We have developed a rapid radioimmunoassay for human F3 which incorporates short incubation times and the use of a preprecipitated second antibody; the assay can be performed in three hours. Specificity studies in buffer systems show prothrombin and prethrombin 1 cross-reacting at a level of 0.001; purified thrombin does not cross-react. In the presence of 5% BSA, prothrombin displays considerably less cross-reactivity. No immunoreactive material to F3 antibodies could be detected in 400 μL of plasma. Serum, obtained from whole blood clotting, contained measurable quantities of F3 (40-100 ng/mL). This amount in serum represents only 5-10% of the theoretical amount available should all of the fragment be hydrolytically cleaved during the conversion of prothrombin to thrombin. This assay procedure is currently being utilized to monitor the activation of purified human prothrombin in the absence and presence of selected plasma inhibitors. (Supported in part by NIH 05384-17 and the Michigan Heart Association).

Human Prothrombin Activation: Determination of Plasma and Serum Levels of Prothrombin Fragment 3 by Radioimmunoassay

1979 ◽  
Author(s):  
Daniel A. Walz ◽  
Thomas R. Brown
Keyword(s):  
Blood Clotting ◽  
Factor Xa ◽  
Heart Association ◽  
Serum Levels ◽  
Cross Reactivity ◽  
Assay Procedure ◽  
A Chain ◽  
Prothrombin Activation ◽  
Theoretical Amount

Human prothrombin activation is unique in that, in addition to the release of fragment 1-2 (F1·2) from the NH-terminus of prothrombin by factor Xa during the generation of thrombin, an additional 13 residue polypeptide, fragment 3 (F3), is autocatalytically removed”from the amino-terminus of the thrombin A chain. We have developed a rapid radioimmunoassay for human F3 which incorporates short incubation times and the use of a preprecipitated second antibody; the assay can be performed in three hours. Specificity studies in buffer systems show prothrombin and prothrombin 1 cross-reacting at a level of 0.001; purified thrombin does not cross-react. In the presence of 5% BSA, prothrombin displays considerably less cross-reactivity. No immunoreactive material to F3 antibodies could be detected in 400of plasma. Serum, obtained from whole blood clotting, conr tained measurable quantities of F3 (40-100 ng/mL). This amount in serum represents on 5–10% of the theoretical amount available should all of the fragment be hydrolytically cleaved during the conversion of prothrombin to thrombin. This assay procedure Is currently being utilized to monitor the activation of purified human prothrombin in the absence and presence of selected plasma inhibitors. (Supported in part by NIH 05384-17 and the Michigan Heart Association).

IMMUNOLOGICAL DETERMINATION OF PITUITARY LUTEINIZING HORMONE IN THE URINE OF FERTILE AND POST-MENOPAUSAL WOMEN AND ADULT MEN

1962 ◽  
Vol 39 (4) ◽  
pp. 539-546 ◽  
Author(s):  
Leif Wide ◽  
Carl Gemzell
Keyword(s):  
Luteinizing Hormone ◽  
Haemagglutination Inhibition ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Human Pituitary ◽  
Adult Men ◽  
Menopausal Women ◽  
Post Menopausal ◽  
Inhibition Reaction

ABSTRACT An immunological method to assay human pituitary luteinizing hormone (HPLH) in urine is described. It is based on the fact that HPLH crossreacts with human chorionic gonadotrophin (HCG) in an haemagglutination inhibition reaction between HCG-coated blood cells and rabbit HCG-antisera. During the menstrual cycle the excretion of HPLH reached a peak of 200–400 U per liter at the time of ovulation. In the urine of post-menopausal women the concentration of HPLH was between 100 and 400 U per liter. In the urine of adult men the concentration of HPLH was between 50 and 160 U per liter.

Is incomplete estradiol suppression during aromatase inhibitor treatment in post-menopausal patients with breast cancer due to insufficient systemic drug concentrations?

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 1063-1063
Author(s):  
Daniel Louis Hertz ◽  
Kelley M. Kidwell ◽  
Kelly A Speth ◽  
Christina L Gersch ◽  
Zeruesenay Desta ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Logistic Regression ◽  
Plasma Concentrations ◽  
High Plasma ◽  
Limit Of Quantification ◽  
Drug Concentrations ◽  
Menopausal Women ◽  
Er Positive ◽  
Post Menopausal ◽  
Positive Breast Cancer

1063 Background: Aromatase inhibitors (AI) suppress estrogen biosynthesis and are effective treatments for estrogen receptor (ER)-positive breast cancer. In a prospectively enrolled cohort we observed a subset of post-menopausal women who exhibit high plasma estradiol (E2) concentrations during AI treatment, which could potentially contribute to treatment failure. We tested the hypothesis that incomplete E2 suppression is due to insufficient systemic AI concentrations. Methods: Five hundred post-menopausal women with ER-positive breast cancer were randomized to daily exemestane (Exe) 25 mg or letrozole (Let) 2.5 mg. Plasma E2 was measured using GC/MS/MS (lower limit of quantification (LLOQ) = 1.25 pg/mL) at baseline and after 3 months. Let and Exe plasma concentrations measured after 1 or 3 months were compared with the magnitude of E2 depletion using four complementary statistical procedures to assess associations of drug concentrations with: 1) a binary outcome of E2 suppression below LLOQ (logistic regression), 2) 3-month E2 concentrations (linear regression), 3) absolute change from baseline in E2 concentrations (Spearman correlation), and 4) an ordinal outcome defined by E2: decreased to below LLOQ, decreased but not to LLOQ, stayed the same, or increased from baseline (cumulative logistic regression). Results: 397 patients with E2 and AI concentration measurements were evaluable (Exe n = 199, Let n = 198). Thirty (7.6%) patients (Exe n = 13, Let n = 17) had E2 concentrations above the LLOQ at 3 months (range: 1.42-63.8 pg/mL). Exe and Let concentrations were not associated with achievement of unmeasurable E2 concentrations, on-treatment E2 concentrations, E2 change from baseline, or ordinal groupings of E2 change (all p > 0.05). In a parallel analysis there was no association of estrone-sulfate and drug concentrations (data not shown). Conclusions: Our results suggest that circulating drug concentrations do not explain incomplete E2 suppression in women receiving AI therapy. Additional studies are underway to determine whether age, body mass and genetic variation in the aromatase enzyme influence AI treatment response.

Radioimmunoassay for 4-hydroxyoestrone in human urine

1981 ◽  
Vol 97 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Günter Emons ◽  
Claudia Mente ◽  
Rudolf Knuppen ◽  
Peter Ball
Keyword(s):  
Human Urine ◽  
Gas Chromatography Mass Spectrometry ◽  
Clear Cut ◽  
High Affinity ◽  
Assay Procedure ◽  
Female Children ◽  
Bovine Serum Albumin Conjugate ◽  
Order Of Magnitude ◽  
Excretion Rates

Abstract. Under the protection of ascorbic acid a 4-hydroxyoestrone-bovine serum albumin conjugate was prepared containing intact 4-hydroxyoestrone as determined by gas chromatography-mass spectrometry. Using this antigen, antibodies with high affinity and specificity for 4-hydroxyoestrone were raised in rabbits. An assay procedure for the determination of 4-hydroxyoestrone in human urine and the assessment of its reliability are described. The following urinary excretion rates were found: male children 0.29 μg/24 h, female children 0.35 μg/24 h, men (20–40 years) 1.6 μg/24 h, men (>50 years) 1.8 μg/24 h, women, follic. 2.0 μg/24 h, pre-ov. 5.3 μg/24 h, luteal 2.4 μg/24 h, women, pregnant, first trim. 30.0 μg/24 h, second trim. 64.0 μg/24 h, third trim. 48.0 μg/24 h, women, post-men. 1.5 μg/24 h. Thus the amounts of 4-hydroxyoestrone excreted in human urine are about 1/3 to 1/10 of those of 2-hydroxyoestrone. During the menstrual cycle the excretion rates of 4-hydroxyoestrone are in the same order of magnitude as those of oestradiol and show a clear-cut pre-ovulatory peak.

Early effects of ethinyloestradiol and norethisterone treatment in post-menopausal women on bone resorption and calcium regulating hormones

1985 ◽  
Vol 69 (3) ◽  
pp. 265-271 ◽  
Author(s):  
Peter L. Selby ◽  
Munro Peacock ◽  
Stuart A. Barkworth ◽  
Wendy B. Brown ◽  
Geoffrey A. Taylor
Keyword(s):  
Bone Resorption ◽  
Plasma Levels ◽  
Plasma Concentrations ◽  
Vitamin D Binding Protein ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Menopausal Women ◽  
Early Effects ◽  
Post Menopausal ◽  
Free Plasma

1. The early effects of sex steroid therapy were assessed in 28 normal post-menopausal women, 18 treated with ethinyloestradiol and 10 with norethisterone. 2. There was a reduction in the fasting urinary excretion of both calcium and hydroxyproline with both treatments, indicating reduced bone resorption. This was apparent after 1 week of therapy but became more marked after 3 weeks. 3. These changes were not accompanied by any changes in plasma levels of calcitonin or parathyroid hormone. 4. Patients receiving ethinyloestradiol showed a marked increase in plasma 1,25-dihydroxyvitamin D (1,25-(OH)2D) concentration but this was explicable entirely in terms of increased plasma levels of vitamin D binding protein. There was no change in the free plasma level of 1,25(OH)2D. Patients treated with norethisterone showed no increase in plasma concentrations of 1,25(OH)2D. 5. We conclude that both ethinyloestradiol and norethisterone have a rapid and similar effect in reducing bone resorption. This is not mediated via the plasma levels of the calcium regulating hormones.

Determination of clovoxamine concentration in human plasma by electron capture gas chromatography.

1981 ◽  
Vol 27 (7) ◽  
pp. 1210-1212 ◽  
Author(s):  
H E Hurst ◽  
D R Jones ◽  
C H Jarboe ◽  
H deBree
Keyword(s):  
Clinical Trial ◽  
Gas Chromatography ◽  
Human Plasma ◽  
Electron Capture ◽  
Plasma Concentrations ◽  
Antidepressant Drug ◽  
Internal Standard ◽  
Early Clinical Trial ◽  
Coefficients Of Variation

Abstract The antidepressant drug clovoxamine can be specifically and sensitively quantitated in human plasma by electron capture gas chromatography. Clovoxamine and the internal standard fluvoxamine are extracted into ethyl acetate from plasma at pH 12, back-extracted into phosphoric acid, and hydrolyzed at 90 degrees C to form ketone derivatives, which are then re-extracted into hexane for injection into the chromatograph. As little as 1 microgram of clovoxamine per liter of plasma can be measured. The coefficients of variation (CV) for th analysis at concentrations of 10 and 100 micrograms/L are respectively: within-run, 5.4% and 2.7%; between-run, 17.5% and 7.0%. When this assay was applied to plasma from individuals involved in an early clinical trial of clovoxamine, steady-state plasma concentrations ranged from 50 to 77 micrograms/L 3 h after a 50-mg oral dose of clovoxamine fumarate.

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