No abstract

Elevated levels of a group of substances with digoxin-like immunoreactivity (DLIS) are present in biological fluids of newborns. These endogenous substances could also have the biological properties of cardiac glycosides, such as natriuretic and vasoconstrictor activity. Therefore, DLIS could be involved in electrolyte and volume regulation in infants. We measured DLIS, electrolyte (Na⁺, K⁺, Cl^––) and creatinine concentrations in 157 urine samples collected from full-term and preterm infants, with the aim to establish if a correlation exists between the urinary DLIS levels and the respective values of these electrolytes. Significant and positive correlations were found between the urinary concentrations of DLIS and electrolytes. In addition, electrolyte values correlated significantly between themselves. DLIS, K⁺ and Cl^–– values correlated positively with urinary creatinine concentrations (n = 142). A significant multiple correlation was found among DLIS concentrations and creatinine and Cl^–– values. We also studied the DLIS concentrations in serum samples collected at birth in peripheral blood of the mothers and in umbilical cord and gastric aspirate of 5 full-term infants. We observed that DLIS values in newborns are significantly higher than the respective values of the mothers. In conclusion, our data do not demonstrate a clear relationship between DLIS and electrolyte concentrations in urine samples of newborns. Further investigations are necessary to elucidate the biochemical and physiological properties of DLIS.

A method for the determination of progesterone in human plasma by competitive protein-binding is described. This method consists of extraction with petroleum ether, HTLC to purify the extracts and CBG-assay. The reliability criteria of the complete procedure are presented. The method is suitable for application to peripheral blood levels at all stages of the menstrual cycle and in men. The plasma values of progesterone in men and during the follicular and luteal phases of the menstrual cycle were 0.026 ± 0.014, 0.12 ± 0.02 and 0.83 ± 0.58 (S.D.) µg/100 ml, respectively.

Summary The authors describe a radioimmunological method for the determination of testosterone in the peripheral blood of calves, using a group of 7 calves about 4 months old and a second group of 7 between the ages of 12 and 24 months. After the examination in detail of the various phases of the method, the validity criteria are enunciated and the results are reported. The values for prepuberal subjects of 4 months old vary between 57.8 and 71.2 ng./100 ml. of plasma, and for puberal subjects from 250.6 to 750.3 ng./100 ml. of plasma. Finally, the significant features of the method are summarized and the validity of the plasma values obtained is discussed in comparison with the results of other authors. Zusammenfassung Die radioimmunologische Bestimmung von Testosteron im Plasma von Kälbern Die Autoren beschreiben eine radioimmunologische Methode zur Bestimmung von Testosteron im peripheren Blut von Kälbern. 1. Die Untersuchungen wurden an zwei Gruppen von je 7 Tieren ausgeführt (Alter der 1. Gruppe: 4 Monate, Alter der 2. Gruppe: 12–24 Monate). Ergebnisse: 1. Gruppe 57,8–71,2 ng/100 ml; 2. Gruppe 250,6–750,3 ng/100 ml. Résumé Determination radioimmunologique de la testostérone dans le plasma des veaux Les auteurs décrivent une méthode radioimmunologique, pour déterminer la testostérone dans le sang périphérique des veaux. Les examens sont pratiqués sur deux groupes de 7 animaux (âge dans le premier groupe: 4 mois; âge dans le deuxième groupe: 12–24 mois). Résultats: groupe 1 57,8–71,2 ng/100 ml; groupe 2 250,6–750,3 ng/100 ml. Resumen La valoración radioinmunológica de testosterona en el plasma sanguíneo de terneros Los autores describen una técnica radioinmunológica para valorar testosterona en la sangre periférica de terneros. Los estudios se llevaron a cabo en dos grupos de 7 animales cada vez (edad del grupo 1°:4 meses, edad del grupo 2°: 12–24 meses). Resultados: grupo 1° 57,8–71,2 ng/100 ml; grupo 2° 250,6–750,3 ng/100 ml de plasma.