SEPARATION OF ANTIBODY-BOUND AND FREE HUMAN FOLLICLE-STIMULATING AND LUTEINIZING HORMONES BY ETHANOL-AMMONIUM ACETATE

1973 ◽  
Vol 72 (4) ◽  
pp. 643-653 ◽  
Author(s):  
A. Römmler ◽  
B. B. Saxena
Keyword(s):  
Ammonium Acetate ◽  
Acetate Solution ◽  
Plasma Samples ◽  
Human Pituitary ◽  
Luteinizing Hormones ◽  
Low Protein ◽  
The Mean ◽  
Post Menopausal ◽  
Normal Men

ABSTRACT The use of 66% ethanol containing 6.6% ammonium acetate provided a simple and economical method for the separation of antibody-bound and free 131I-labelled hormones in incubation mixtures of low protein concentrations used in the radioimmunoassay of human pituitary FSH and LH. The accuracy of the procedure was confirmed by similar results obtained in the evaluation of radiation damage to the tracer, binding of the tracer to the antibody and the separation of the antibody-bound and free 131I-labelled hormones by the use of ethanol-ammonium acetate solution and chromato-electrophoresis. The sensitivity of the measurement of the hormones was 10 pg with a precision of ± 5%; thus allowing the determination of hormone concentrations in as little as 20 to 50 μl of the plasma samples. There was a 98.5 to 102% recovery of the hormones added to the plasma samples of pre-determined hormone concentrations. The use of highly purified antigens for radioisotopic labelling and standard as well as purified antisera provided specific measurements of FSH and LH in the plasma. Various dilutions of a post-menopausal plasma sample yielded responses parallel to those obtained for the doseresponse curves of the FSH and LH standards by logit-log plots, thus confirming the validity of the assay. The mean plasma FSH and LH levels in normal men, children and in women during the luteal phase were 2.7 and 2.6, 1.1 and 1.2, and 1.8 and 2 ng/ml, respectively, whereas the plasma of hypophysectomized subjects showed trace to detectable levels of FSH and LH.

LC–MS/MS Determination of Apigenin in Rat Plasma and Application to Pharmacokinetic Study

2020 ◽  
Vol 21 ◽  
Author(s):  
Shixing Zhu ◽  
Jiayuan Zhang ◽  
Zhihua Lv ◽  
Mingming Yu
Keyword(s):  
Formic Acid ◽  
Pharmacokinetic Study ◽  
Ammonium Acetate ◽  
Rat Plasma ◽  
Biological Properties ◽  
Plasma Samples ◽  
Supply Rate ◽  
Natural Plant ◽  
Ammonium Acetate Buffer

Background: Apigenin, a natural plant flavone, has been shown to possess a variety of biological properties. Objective: In this report, a highly selective and sensitive LC-MS/MS method was developed and validated for the determination of apigenin in rat plasma. Methods: Analysts were separated on the HSS T3 column (1.8 μm 2.1×100 mm) using acetonitrile and 0.1% formic acid in 2 mM ammonium acetate buffer at a supply rate of 0.200 mL/min as eluent in gradient model. Results: Plasma samples were treated by protein precipitation using acetonitrile for the recovery ranging from 86.5% to 90.1% for apigenin. The calibration curves followed linearity in the concentration range of 0.50-500 ng/mL. The inter-day and intra-day precisions at different QC levels within 13.1% and the accuracies ranged from -10.6% to 8.6%. Conclusion: The assay has been successfully applied to the pharmacokinetic study of apigenin in rats.

ENZYMATISCH-FLUOROMETRISCHE BESTIMMUNG DER CORTISOLBINDUNGSKAPAZITÄT DES PLASMA

1967 ◽  
Vol 56 (1) ◽  
pp. 99-106 ◽  
Author(s):  
K. Leybold ◽  
J. Rieper ◽  
L. Weissbecker
Keyword(s):  
Binding Capacity ◽  
Liver Microsomes ◽  
Mean Value ◽  
Female Rats ◽  
Plasma Samples ◽  
Simple Method ◽  
Adult Men ◽  
The Mean ◽  
Precision And Accuracy

ABSTRACT A simple method for the determination of cortisol-binding capacity is described. For saturation of the cortisol-binding proteins, plasma samples are incubated with an excess of cortisol. In the next step NADPH and liver microsomes of female rats are added. The microsomal Δ4-3-ketosteroid hydrogenase only reduces non protein-bound cortisol to tetrahydrocortisol-5α. Then the steroids are extracted by dichloromethane, and after some purification steps analyzed by fluorometry. Tetrahydrocortisol gives practically no fluorescence. The cortisol determined by this method corresponds to protein-bound cortisol and indicates the extent of cortisolbinding capacity. Precision and accuracy of the method were found to be good. The values of cortisol-binding capacity obtained by our method are compared with the results of other authors. The mean value of adult men was 25.5 ± 3.4 μg/100 ml, that of pregnant women, mens IX-X, 42.3 ± 4.2 μg/100 ml.

Colorimetric Method for Rapid Determination of Serum Arginase

1967 ◽  
Vol 13 (10) ◽  
pp. 900-908 ◽  
Author(s):  
Brigitta Mellerup
Keyword(s):  
Rapid Determination ◽  
Colorimetric Method ◽  
Normal Range ◽  
Clinical Routine ◽  
Mean Values ◽  
Enzymatic Formation ◽  
Significant Difference ◽  
The Mean ◽  
Normal Men

Abstract A method for the determination of serum arginase is given which combines the enzymatic formation of urea with the sensitive method of Coulombe (1) for measuring this substance. This procedure allows more accurate determinations in the normal range than do previous methods described and is convenient for clinical routine. Significant difference is found between the mean values of normal men and women, 3.9 units/L. for the former and 2.9 units/L. for the latter.

scholarly journals HPLC Analysis of Stemokerrine and Oxystemokerrine in the Thai Medicinal Plant Stemona kerrii

2012 ◽  
Vol 7 (10) ◽  
pp. 1934578X1200701
Author(s):  
Sumet Kongkiatpaiboon ◽  
Vichien Keeratinijakal ◽  
Wandee Gritsanapan
Keyword(s):  
Hplc Analysis ◽  
Ammonium Acetate ◽  
Raw Materials ◽  
Gradient System ◽  
Acetate Solution ◽  
Standardization Method ◽  
Pharmaceutical Development ◽  
Percent Recovery ◽  
Two Samples

A HPLC-UV method was developed and validated for determination of stemokerrine and oxystemokerrine in Stemona kerrii roots. The chromatographic separation was performed on a Hypersil BDS C18-column eluted with methanol: 50 mM ammonium acetate solution using a gradient system with a flow rate of 1 mL/min and detection at 300 nm. Stemokerrine and oxystemokerrine showed a linear relationship within the range of 0.5-100 μg/mL. The method was shown to be precise with a RSD <2%. The average percent recovery of stemokerrine was 101.6% and for oxystemokerrine 99.5%. Two samples of S. kerrii were analyzed and the average contents of stemokerrine and oxystemokerrine were 0.2 and 0.05%, w/w, respectively. The present work will provide a useful standardization method for S. kerrii raw materials for further pharmaceutical development.

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.

scholarly journals Accuracy of determination of the glomerular filtration marker iohexol by European laboratories as monitored by external quality assessment

2019 ◽  
Vol 57 (7) ◽  
pp. 1006-1011 ◽  
Author(s):  
Gunnar Nordin ◽  
Sara Ekvall ◽  
Carolina Kristoffersson ◽  
Ann-Sofie Jonsson ◽  
Sten-Erik Bäck ◽  
...  
Keyword(s):  
Glomerular Filtration Rate ◽  
Quality Assessment ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
External Quality Assessment ◽  
Plasma Samples ◽  
High Quality ◽  
External Quality ◽  
The Mean

Abstract Background Glomerular filtration is the most important kidney function. The most accurate glomerular filtration rate (GFR) estimates are based on the clearance of exogenous filtration markers. Of these, iohexol is the only exogenous marker that is included in an external quality assessment (EQA) scheme. The aim of the present study was to evaluate the performance of the European laboratories participating in Equalis’ EQA scheme for iohexol. Methods Weighed amounts of iohexol (Omnipaque) were added to plasma samples and distributed to laboratories participating in the EQA scheme for iohexol. All laboratories performed the assays in a blinded fashion. Results The number of participating laboratories varied between 27 and 34 during the study period. Iohexol was determined by HPLC in 77% of the laboratories and by UPLC/MS/MS methods in 15% of the laboratories. The mean interlaboratory coefficient of variation was 4.7% for the HPLC methods and 6.4% for the UPLC/MS/MS methods. The mean bias between calculated and measured iohexol values was –1.3 mg/L (95% confidence interval ±0.3) during the first part of the study period and 0.1 mg/L (±0.3) during the later part. Conclusions The low interlaboratory variation demonstrates that iohexol can be measured reliably by many laboratories and supports the use of iohexol as a GFR marker when there is a need for high quality GFR measurements.

Malondialdehyde Kit Evaluated for Determining Plasma and Lipoprotein Fractions that React with Thiobarbituric Acid

1992 ◽  
Vol 38 (5) ◽  
pp. 704-709 ◽  
Author(s):  
M J Richard ◽  
B Portal ◽  
J Meo ◽  
C Coudray ◽  
A Hadjian ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Thiobarbituric Acid ◽  
Low Density Lipoproteins ◽  
Low Density ◽  
Plasma Samples ◽  
Very Low Density Lipoproteins ◽  
Lipid Fractions ◽  
Analytical Recovery ◽  
The Mean

Abstract The determination of thiobarbituric acid reactants (TBARs) is a widely used method for investigating overall lipid peroxidation. An assay kit that could be used with plasma and lipid fractions would facilitate standardization of the method. The results reported here indicate that the malondialdehyde (MDA) kit manufactured by Sobioda (Grenoble, France) complies with criteria of good analytical practices. The detection limit was 0.11 mumol of MDA per liter of plasma. The within-run (CV = 1.8-3.3%) and between-run (CV = 3.3-4.4%) precisions were acceptable. The analytical recovery of MDA after supplementing human plasma samples with tetraethoxypropane standards varied from 88% to 100%. The mean (SD) lipoperoxide concentration determined in 32 healthy adults, ages 20-40 years, was 2.51 (0.25) mumol/L. No significant sex-related difference was noted: 2.57 (0.28) in men vs 2.44 (0.20) mumol/L in women. Applying the method to lipid fractions showed that lipoprotein fractions contain relatively little MDA: 0.07 (0.03) mumol/L of plasma for very-low-density lipoproteins and 0.19 (0.10) mumol/L for low-density lipoproteins.

STUDIES ON PITUITARY GONADOTROPHINS IN HUMAN PLASMA

1966 ◽  
Vol 52 (3) ◽  
pp. 341-347 ◽  
Author(s):  
Paul J. Keller
Keyword(s):  
Ammonium Acetate ◽  
Plasma Samples ◽  
Men And Women ◽  
Male And Female ◽  
Mean Values ◽  
Significant Difference ◽  
Human Menopausal Gonadotrophin ◽  
Group A ◽  
Reference Preparation ◽  
The Mean

ABSTRACT Gonadotrophic activity was estimated in individual plasma samples of 46 male and female subjects of all ages. The plasma was extracted by means of an ammonium acetate-ethanol procedure and tested biologically by the mouse uterine weight assay. The values in postmenopausal plasma ranged from 10 to 46 milligram-equivalents of the 2nd International Reference Preparation for Human Menopausal Gonadotrophin per litre. Plasma of men and women in the reproductive years contained 0.6–3.0 and 0.5–2.4 milligram-equivalents of the 2nd IRP per litre. The results in female plasma were assembled according to the day of the menstrual cycle. Though there was no significant difference in the mean values between group A (days 1–9), B (days 10–19) and C (days 20–30), the highest value was observed on the 13th day of the cycle of a 37 years old woman.

Aluminium, extractable from soil samples by the acid ammonium acetate soil-testing method

1968 ◽  
Vol 40 (2) ◽  
pp. 54-59
Author(s):  
Osmo Mäkitie
Keyword(s):  
Acetic Acid ◽  
Ammonium Acetate ◽  
Acid Soils ◽  
Soil Samples ◽  
Ammonium Acetate Solution ◽  
Soil Testing ◽  
Acetate Solution ◽  
Mean Values ◽  
Testing Method ◽  
The Mean

The extractant, 0.5 M acetic acid –0.5 M ammonium acetate at pH 4.65, which is used in soil-testing, extracts relatively high amounts of aluminium from acid soils. The mean values of acetate-extractable aluminium at pH 4.65, 1.75 meq Al/100 g of soil, and of exchangeable aluminium (M KCI extraction), 0.41 meq Al were obtained from a material of 30 samples of acid soils (Table 2). Several other acetic acid ammonium acetate extractants, from M acetic acid to M ammonium acetate solution were also used for studying the extractability of soil aluminium. The soil-testing extractant can be used for the estimation of the soluble amounts of aluminium in acid soils, however, further studies are needed for a better interpretation of the ammonium acetate extractable (at pH 4.65) aluminium in our soils.

Simple extraction method and radioimmunoassay for somatostatin in human plasma.

1981 ◽  
Vol 27 (6) ◽  
pp. 888-891 ◽  
Author(s):  
T L Peeters ◽  
Y Depraetere ◽  
G R Vantrappen
Keyword(s):  
Human Plasma ◽  
Plasma Proteins ◽  
Extraction Method ◽  
Plasma Samples ◽  
Analytical Recovery ◽  
Simple Extraction ◽  
The Mean ◽  
Radioimmunological Determination ◽  
Dilution Curves

Abstract Interference by human plasma proteins in the radioimmunological determination of somatostatin was eliminated by subjecting plasma samples to acid--ethanol precipitation. The assay was performed on the lyophilized supernate from 300 microliters of human plasma, with reagents that are commercially available. Sensitivity was 2.6 pg, corresponding to 8.7 ng/L of plasma. The intra-assay CV was 8%; the inter-assay CV was 12% for a low (30 ng/L) and 15% for a high (100 ng/L) standard. The mean analytical recovery of exogenous somatostatin from plasma was 95%, and the standard synthetic cyclic somatostatin showed parallel dilution curves with extracted plasma samples. Neither gastrin HG-17 and HG-34, pentagastrin, secretin, glucagon, vasoactive intestinal polypeptide, substance P, nor pancreatic polypeptide interfered in the assay system. Mean immunoreactive somatostatin in 20 normal fasting subjects was 31.5 (SD 15.6) ng/L and ranged from 14 to 67 ng/L.

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