Penetration of melanocytes from embryonic Japanese quail peritoneum into associated embryonic avian gonads,grown on chicken chorioallantoic membrane

Summary After association on chorioallantoic membrane (CAM) of an embryonic bird testis with pigmented peritoneum from a Japanese quail embryo, numerous melanocytes penetrate in its interstitial tissue. If, instead of a testis, an ovary is transplanted under similar conditions, then the melanocytes may be found in the medulla or between the secondary sex cords at the rim of the ovary.The author is very grateful to Prof.L. Vakaet, R. U. C. A. Antwerp, for his valuable suggestions, and to MissC. Vaniioecke for her technical assistance.     

An improved bioassay method for kinins

Zusammenfassung Unter Ausnützung der besonderen Empfindlichkeit der Femoralarterie des Kaninchens für Kinin wurde die autoperfusionierte Hinterextremität beobachtet. Intraarterielle Injektion von 0,5 ng synthetisiertem Bradykinin ergab eine messbare, dosisabhängige Vasodilatation in fast allen Versuchstieren. Dieses Kreislaufpräparat erweist sich zur Kinin-Bestimmung als besonders geeignet.     

Method for long term delivery of soluble agents to the chick chorioallantoic membrane

Summary Osmotic minipumps were used to administer thyroxine to the chick embryo. This technique proved to be a convenient and efficacious method for the delivery of soluble agents to the chorioallantoic membrane. The thyroxine induced the precocious appearance of extensive cell sloughing by the corneal epithelium.     

An improved electrophoretic method for a screening program for haemoglobinopathies

Summary A method for a screening program for haemoglobinopathies in a starch agar gel mixed with saponin is presented. Normal and abnormal blood containing haemoglobins S, C, I, M Boston, D Punjab, beta thalassaemia major and beta thalassaemia minor, were applied, in a tray with the capacity for 100 samples. The electrophoresis was performed in 45 min using 300 V. This method offers special advantages for the examination of a large number of samples, using a small amount of whole blood and without the previous preparation of haemoglobin solution.Acknowledgments. We would like to express our gratitude to Dr C. Daghlian and Dr Lewis J. Greene for their valuable suggestions. We also thank the Conselho Nacional do Desenvolvimento Científico e Tecnológico, CNPq, for financial support.     

An unusual basement membrane underlying intestinal epithelium of the platypus (Ornithorhynchus anatinus)

Zusammenfassung Es werden die besonderen strukturellen Eigenschaften der Basalmembran beschrieben, die unter dem Mucosaepithel aller Darmregionen (Magen bis Rectum) des Schnabeltiers (Ornithorhynchus anatinus) liegt.     

An improved method for flow dialysis studies with highly increased diffusion rates

Summary An improved flow dialysis procedure with highly increased diffusion rates has been developed allowing the study of small changes in the rate of diffusion. The application of the method described with only a few individual experiments, and with the use of small amounts of biological material, gives much information about binding systems.This work was supported by the Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung (grant No. 3.1650.73).     

An improved method for estimating the activity of a mouse with the photoswitch

A new method for estimating the activity of a mouse by means of the photoswitch is contrived. This device can follow the activity with high fidelity and notable sensitivity, as compared with the conventional method.     

An improved method for the study of reagin-mediated mast cell degranulation in rats

Zusammenfassung Eine Methode zum Studium der reaginvermittelten Mastzelldegranulation im Mesenterium der Ratte, bei der der Grad der unspezifischen Degranulation sehr niedrig ist, wird beschrieben. Die spezifische (reaginvermittelte) Reaktion ist hemmbar durch die drei Pharmaka Fenoterol, Salbutamol und Natrium-cromoglycat, deren antiasthmatische Wirkung bekannt ist.

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The technical assistance of MissPetra Festersen is gratefully acknowledged.     

An improved method for estimating the activity of a mouse with the photoswitch

Summary A new method for estimating the activity of a mouse by means of the photoswitch is contrived. This device can follow the activity with high fidelity and notable sensitivity, as compared with the conventional method.     

An improved method for the isolation of eosinophilic leukocytes from normal human blood

Summary A relatively short and simple method for the isolation of the eosinophils from normal human blood is reported. With a recovery of about 45–55%, cell preparations, showing a degree of purity of 90–98%, are obtained. The isolated cells are morphologically intact and viable, as assessed by the trypan blue exclusion test and by active phagocytosis.The authors are indebted to the Schweizerischer National-fonds zur Förderung der wissenschaftlichen Forschung for financial support.     

An improved method for the collection of large numbers of inseminated eggs ofDrosophila melanogaster

Zusammenfassung Es wird eine verbesserte Methode beschrieben, mit der innerhalb einer Sammelperiode von 3 min etwa 50-100 frisch besamte Eier vonDrosophila melanogaster gewonnen werden können. Verglichen mit den bisher üblichen Sammelperioden von 10, 30 oder mehr min erhält man wesentlich stadienhomogenere Gelege. Eine weitere Verkürzung der Sammelperiode unter 3 min ist wegen der stark abnehmenden Anzahl Eier je Gelege nicht möglich. Vorausgesetzt, dass alle Störungen der Fliegen durch Erschütterungen, Licht, Temperaturschwankungen usw ausgeschaltet werden, können z.B. für strahlenbiologische Experimente zahlreiche 3-min-Gelege im Laufe von 6 oder mehr Stunden gewonnen werden.

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Work supported by Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung and Jubiläumsfond 1930 der ETH.