This study develops a simple and low-cost 3D paper-based analytical device (3D PAD) for the detection of available phosphate in soil. Epoxy resin is presented as a new hydrophobic material for low-cost mass production of PADs using the screen-printing method. An optimized concentration of epoxy resin solution is screen printed onto Whatman filter paper no. 1 in an easy one-step process to create hydrophobic patterns on PADs. The epoxy resin is air dried at room temperature, without heating or UV curing. This method delivers high reproducibility, resolution, and stability, and the epoxy resin barrier is compatible with both organic solvents and aqueous solutions. The molybdenum blue method is used in this PAD to measure phosphate in a colorimetric assay. The developed 3D PAD attains a linear range of 0.5-40 mg L-1, with a limit of detection (LOD) of 0.25 mg L-1, and a limit of quantitation (LOQ) of 0.83 mg L-1. The relative standard deviation of intra-day measurements is 1.52-2.46%, and the inter-day standard deviation is 1.89-2.74%, indicating satisfactory reproducibility. This 3D PAD was tested for its ability to detect phosphate in a variety of actual soil samples and the results were validated against spectrophotometric analysis using a paired t-test, which showed high accuracy. In short, the new analytical device described in this study is simple, fast, and inexpensive to make and use, providing a versatile phosphate detection tool for many soil types, even in situations when resources are limited.

Pregnenolone was transformed to 21-hydroxypregnenolone by rat adrenal microsomal preparations and to 17α,21-dihydroxypregnenolone by human adrenal microsomal preparations. These data suggest the involvement of alternative pathways via 17α,21-dihydroxypregnenolone in human and via 21-hydroxypregnenolone in rat adrenal corticosteroid biosynthesis.

Slices of adrenal tissue obtained from patients with hypernephroid kidney carcinomas were incubated with [ 3 H]-acetate in the presence or absence of ACTH and/or Triparanol and corticosteroids analyzed. Specific radioactivities of desmosterol, 21-hydroxypregnenolone, deoxycorticosterone, corticosterone, deoxycortisol and cortisol were markedly higher than those of free and esterified cholesterol, pregnenolone, progesterone, and 17-hydroxyprogesterone. Addition of the 24,25-ene-reductase-inhibitor Triparanol, although leading to a marked decrease of specific radioactivities of cholesterol, had only a slight influence on those of deoxycorticosterone, corticosterone, deoxycortisol. The data are taken as evidence for the involvement of alternative pathways in human adrenal steroidogenesis under in vitro conditions, which by-pass cholesterol, pregnenolone, progesterone, 17-hydroxypregnenolone, and 17-hydroxyprogesterone, and proceed through 17,21-dihydroxypregnenolone and/or 21-hydroxypregnenolone.

The biosynthesis of [3H]-20α, 21 dihydroxycholestderol from [3H]-20α-hydroxycholesterol and its transformation to [3H]-21-hydroxypregnenolone by rat adrenal preparations has been demonstrated. 20α-Hydroxycholesterol was transformed to 20α, 21-dihydroxycholesterol by microsomal preparations in the presence of NADPH and 20α-21-dihydroxycholesterol was metabolized to 21-hydroxypregnenolone by mitochondrial preparations in the presence of a NADPH-generating-system. Comparison of the Michaelis-Menten-Kinetics of the steps “20α, 21-dihydroxycholesterol → 21-hydroxycholesterol” and “20α-hydroxycholesterol → pregnenolone” revealed that both compounds behaved as analogue substrates of the desmolase complex. The data are taken as further evidence for the participation of an alternative pathway via the sequence “21-hydroxysterol → 21-hydroxypregnenolone → deoxycorticosterone” in rat adrenal corticosteroid biosynthesis.

Plasma cortisol was determined by a radioimmuno assay during labour, at and after delivery in 16 primigravidas und epidural anaesthesia and was compared with 13 primigravidas, who delivered under pentazocine or pethidine and pudendal block. Cortisol levels decreased after effective epidural anaesthesia during the first stage of labor and for delivery. They increased in the control patients for delivery and was significantly higher than in the patients under epidural anaesthesia. Two and 20 hours post partum cortisol concentrations decreased in both groups. Cortisol levels in the fetuses and newborns was markedly lower than those of mothers. At delivery, the cortisol concentration of the newborns of both groups was the same. The changes of cortisol concentrations in this study support the conclusion that epidural anaesthesia during labor and delivery reduces stress for the mother, but not for the fetus.

Low renin hypertension probably does not represent a clinical entity. In many patients with low renin hypertension blood pressure is normalized by treatment with diuretics only; in these patients a (genetic?) sensitivity to salt might play a predominant role in the pathogenesis of hypertension and renin suppression. In another group of patients renin suppression appears to be secondary to the hypertensive process. This is indicated by the observation that prevalence of low renin hypertension increases with age and that it is more frequent in advanced stages of hypertension. Also a diminished sympathetic tone might play a part in the renin unresponsiveness. Finally, although no positive evidence was found, the possibility cannot be excluded that, at least in some cases, a mineralocorticoid other than aldosterone is involved. Neither in normotensive subjects nor in hypertensive patients, both with normal and with low plasma renin was a correlation between plasma renin concentration and plasma aldosterone concentration following stimulation by upright posture found. More detailed studies will be necessary to clarify the relationship between the renin-angiotensin system and aldosterone secretion during upright posture, in particular in patients with low renin hypertension.

An 6 normalen männlichen Freiwilligen im Alter von 20–26 Jahren wurden Plasmacortisol und -renin stündlich, Plasmaaldosteron, -angiotensinogen und -angiotensinasen alle 3 Std über jeweils 24 Std unter Kontrollbedingungen und anschließend unter Suppression der ACTH-Freisetzung durch Dexamethason gemessen.

In a group of 15 cases the cortisol concentrations were determined in fetal and maternal plasma during labour and after delivery. In maternal plasma the levels were about twice as high as in fetal plasma and rose up to more than 1000 mug/l during labour (x = 639 +/- 222). After delivery the concentrations decreased. In fetal plasma, cortisol increased during labour from x = 173 +/- to x = 276 +/- 75 at the time of delivery and decreased to x = 106 +/- 36 within the first 23 hours. In a second group of 20 cases maternal and umbilical cord blood and blood of the newborn during the first 28 hours after delivery were analyzed. The values were in the same ranges as in the first group. Extremely high maternal levels were not correlated to higher fetal values. The cortisol levels of postmature children did not significantly differ from those of normal babies.

Carbenoxolon-Natrium1 ist ein halbsynthetisches Derivat der aus dem Succus liquiritiae gewonnenen Glycyrrhetinsäure. Glycyrrhetinsäure ist nach Literatur angaben im Süßholzextrakt bis zu 16% enthalten [7, 14]. Im verbleibenden Rest der Droge, dem deglycyrrhizinierten Succus liquiritiae2, konnten mindestens 14 weitere Triterpenderivate, ca. 30 flavonoide Verbindungen wie das spasmolytisch wirkende Liquiritigenin [15], Zucker, Stärke und andere Substanzen in geringer Menge nachgewiesen werden [14].

Journal Article Comparison of Mathematical Transformations and Approximations of Radioassay Dose-Response Curves Get access K Sinterhauf, K Sinterhauf I. Medizinische Klinik und Poliklinik der Universität Mainz Search for other works by this author on: Oxford Academic Google Scholar T Müller, T Müller I. Medizinische Klinik und Poliklinik der Universität Mainz Search for other works by this author on: Oxford Academic Google Scholar H J Spira, H J Spira I. Medizinische Klinik und Poliklinik der Universität Mainz Search for other works by this author on: Oxford Academic Google Scholar D Müller, D Müller I. Medizinische Klinik und Poliklinik der Universität Mainz Search for other works by this author on: Oxford Academic Google Scholar D Lommer D Lommer I. Medizinische Klinik und Poliklinik der Universität Mainz Search for other works by this author on: Oxford Academic Google Scholar Acta Endocrinologica (Norway), Volume 80, Issue 1_Supplement_a, Dec 1975, Page S115, https://doi.org/10.1530/acta.0.080S115 Published: 01 December 1975

Die Funktionsdiagnostik des Hypophysenvorderlappens ist mit Hilfe der synthetischen Releasing-Hormone wesentlich erweitert und verfeinert worden [1]. Erstmals ist es möglich geworden, Störungen im hypothalamo-hypophysären Bereich näher zu lokalisieren. Darüber hinaus besteht heute die Möglichkeit, alle Partialfunktionen des Hypophysenvorderlappens mit geeigneten Stimulationstest zu erfassen und an Hand der Ansprechbarkeit differenziertere Aussagen über eine Schädigung des Hypothalamus und der Hypophyse zu machen. Von besonderem Wert ist die hierdurch gegebene Möglichkeit, zu erkennen, ob das Bemühen um eine selektive Adenomextirpation mit Hilfe moderner neurochirurgischer Techniken [2–4] den gewünschten Erfolg hatte. Auch dürften Verlaufskontrollen mit Stimulationstests es wesentlich erleichtern, Rezidive von endo-krinologischer Seite zu erfassen. Schließlich müßte auch die Substitutionsbedürftigkeit und das Ausmaß der notwendigen Substitution besser erwogen werden können [5].