The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform

Rose Kit A - One of the best experts on this subject based on the ideXlab platform.

  • Determination of Neutral Urinary 17-Oxosteroids with Hydroxide of Hyamine 1O-X in the Zimmermann
    2015
    Co-Authors: Solveig Bjerre, Rose Kit A
    Abstract:

    A modified method for 17-oxosteroid determination is described. The organic base, hydroxide of Hyamine lO-X,#{176}which is stable in methanol, has replaced the unstable ethanolic potassium hydroxide solution in the Zimmermann Reaction. Maximal color development was studied by varying incubation temperature, time, m-dinitrobenzene, and concentration of hydroxide of Hyamine 10-X. An incubation temperature of 370 for 30 mm., with 1 % m-dinitrobenzene in 1 M Hyamine 10-X hydroxide solution, gave close to maximal color. The major urinary 17-oxosteroids, dehydroepiandrosterone, androsterone, and etiocholanolone, gave similar chromogenic values. However, C3 and C20 oxosteroids produced some color in the Zimmermann Reaction, and thus if present in large amounts, interfere. The interference in vitro of 35 drugs was tested, and several drugs were found to interfere. An essentially pigment-free urinary extract was obtained during the washing step, by addition of water to the ethylene dichloride extract containing sodium hydroxide pellets. Comparative 17-oxosteroid studies of urine specimens from laboratory personnel and from patients were performed, based on absorbance at a single wavelength (520 m) and at three wavelengths (Allen correction). Correlation coefficients for the laboratory personnel were.983 for females and.996 for males; for the patients,.974 and.975, respectively. 1THE COLORIMEThIC METHODS most widely used in estimation of urinary 17-oxosteroids are based on the Zimmermann Reaction (20). They de-pend on the color developed when ketones containing a CH2CO grou

Έ. Poteczin - One of the best experts on this subject based on the ideXlab platform.

  • Pehit and Poteczin: Excretion of Individual Unconjugated 17-Oxosteroids 169 Excretion of Individual Unconjugated 17-Oxosteroids by Normal Female Subjects
    2015
    Co-Authors: T. Feher, Έ. Poteczin
    Abstract:

    A method has been described for the determination of individual Unconjugated 17-oxosteroids in human urine. The procedure involves the immediate extraction of the sample, purification steps and a paper Chromatographie separation of steroids. The 17-oxosteroids were evaluated by a Zimmermann-Reaction in situ on the paper, elution of chromogens and spectrophotometry. Values for the excretion of Unconjugated metabolites by healthy female subjects under basal conditions, following corticotrophin and metopirone stimulation, and after administration of testosterone-propionate were also presented. Only very low levels and a preponderance of the 5/?-reduced meta-bolites were observed in the urines studied. Es wird eine Methode f r die Bestimmung der einzelnen unkonjugierten 17-Oxosteroide in Menschenharn beschrieben. Das Verfahren besteht in der direkten Extraktion der Probe, Reinigungsschritten und einer papierchromatographischen Trennung der Steroide. Die 17-Oxosteroide werden bestimmt durch eine Zimmermann-Reaktion in situ auf dem Papier, Elution der Farbstoffe und Spektrophoto

Solveig Bjerre - One of the best experts on this subject based on the ideXlab platform.

  • Determination of Neutral Urinary 17-Oxosteroids with Hydroxide of Hyamine 1O-X in the Zimmermann
    2015
    Co-Authors: Solveig Bjerre, Rose Kit A
    Abstract:

    A modified method for 17-oxosteroid determination is described. The organic base, hydroxide of Hyamine lO-X,#{176}which is stable in methanol, has replaced the unstable ethanolic potassium hydroxide solution in the Zimmermann Reaction. Maximal color development was studied by varying incubation temperature, time, m-dinitrobenzene, and concentration of hydroxide of Hyamine 10-X. An incubation temperature of 370 for 30 mm., with 1 % m-dinitrobenzene in 1 M Hyamine 10-X hydroxide solution, gave close to maximal color. The major urinary 17-oxosteroids, dehydroepiandrosterone, androsterone, and etiocholanolone, gave similar chromogenic values. However, C3 and C20 oxosteroids produced some color in the Zimmermann Reaction, and thus if present in large amounts, interfere. The interference in vitro of 35 drugs was tested, and several drugs were found to interfere. An essentially pigment-free urinary extract was obtained during the washing step, by addition of water to the ethylene dichloride extract containing sodium hydroxide pellets. Comparative 17-oxosteroid studies of urine specimens from laboratory personnel and from patients were performed, based on absorbance at a single wavelength (520 m) and at three wavelengths (Allen correction). Correlation coefficients for the laboratory personnel were.983 for females and.996 for males; for the patients,.974 and.975, respectively. 1THE COLORIMEThIC METHODS most widely used in estimation of urinary 17-oxosteroids are based on the Zimmermann Reaction (20). They de-pend on the color developed when ketones containing a CH2CO grou

N. A. D’amato - One of the best experts on this subject based on the ideXlab platform.

  • Method for Screening Urinary Steroids by Gas Chromatography
    2015
    Co-Authors: Paul Trocha, N. A. D’amato
    Abstract:

    Numerous methods are available for measuring urinary steroids in evaluating endocrine dysfunctions. Measure-ments of these particular steroids, or groups of them, usually involve tedious isolation methods, corrections for interferences and losses of the steroid, and (or) expensive reagents. We show how gas-liquid chromatography pro-vides a rapid, sensitive, and direct method for several steroid metabolites in urine. Androstanol, androsterone, etiocholanolone, dehydroisoandrosterone, pregnanediol, pregnanetriol, 11-keto- 1 -ketosteroids, and the 11/3-hydroxy- 17-ketosteroids can be identified and quanti-fied. AddItIonal Keyphrases: diagnostic aids ‘ 1 7-ketosteroids- sex steroids. Zimmermann Reaction compound en-docrine disorders. normal values effects of pregnancy, menstrual cycle. relative retention time data Analysis for steroidal compounds in urine has pro-duced significant progress in diagnosing various meta-bolic disorders. Colorimetric methods such as the Zimmermann (1) and Porter-Silber Reaction (2) are still the most popular techniques for determining the con-centration of several similar steroidal compounds, whereas immunoassays are useful, but expensive, for quantitating specific steroids. Unlike the colorimetric and immunoassays, gas-liquid chromatography can be used to determine both the identities and concentra-tions of individual as well as classes of steroids in one run, but much time and effort is usually expended in setting up and operating the instrument. A method was therefore sought for rapid screening for endocrine dis-orders. Gas-liquid chromatography was chosen as the tech-nique for studying urinary steroids because it is sensitiv

T. Feher - One of the best experts on this subject based on the ideXlab platform.

  • Pehit and Poteczin: Excretion of Individual Unconjugated 17-Oxosteroids 169 Excretion of Individual Unconjugated 17-Oxosteroids by Normal Female Subjects
    2015
    Co-Authors: T. Feher, Έ. Poteczin
    Abstract:

    A method has been described for the determination of individual Unconjugated 17-oxosteroids in human urine. The procedure involves the immediate extraction of the sample, purification steps and a paper Chromatographie separation of steroids. The 17-oxosteroids were evaluated by a Zimmermann-Reaction in situ on the paper, elution of chromogens and spectrophotometry. Values for the excretion of Unconjugated metabolites by healthy female subjects under basal conditions, following corticotrophin and metopirone stimulation, and after administration of testosterone-propionate were also presented. Only very low levels and a preponderance of the 5/?-reduced meta-bolites were observed in the urines studied. Es wird eine Methode f r die Bestimmung der einzelnen unkonjugierten 17-Oxosteroide in Menschenharn beschrieben. Das Verfahren besteht in der direkten Extraktion der Probe, Reinigungsschritten und einer papierchromatographischen Trennung der Steroide. Die 17-Oxosteroide werden bestimmt durch eine Zimmermann-Reaktion in situ auf dem Papier, Elution der Farbstoffe und Spektrophoto