The electron microscopy of fluorescent dextrans (FITC-dextrans) in thin sections of tissue

Summary Fluorescein-coupled dextrans (FITC-Ds) were detected in sections in the electron microscope using 4 different contrasting methods when tissue was postfixed in osmium tetroxide. Endogeneous glycogen was also stained by the methods used, but FITC-D particles appeared smaller and more irregular, and in other locations. In dextranase treated specimens glycogen was still visible, while FITC-D was not.Acknowledgments. The author is grateful to Susan Max-Jacobsen, Kjeld Stub and Sonja Fich for excellent technical assistance. The author was supported by a research fellowship from the Danish Medical Research Council (12–1688).     

Stimulation of human chorionic gonadotropin and progesterone secretion by tumor promoters,phorbol ester and teleocidin B,in cultured choriocarcinoma cells

Summary Both 12-O-tetradecanoyl-phorbol-1-acetate and teleocidin B stimulated the secretion of human chorionic gonadotropin by cultured choriocarcinoma cells. These tumor promoters also stimulated production of progesterone in the cells. However, the 2 tumor promoters did not exert a marked effect on the cellular binding of epidermal growth factor that also had a stimulatory effect on production of these hormones.     

Comparative evaluation of 7 helminth antigens in the enzyme-linked immunosorbent assay (E.L.I.S.A.).

112 sera from Europeans with parasitologically proven helminthiasis were tested in the enzyme-linked immunosorbent assay (E.L.I.S.A.) against 6 crude extracts of various helminths (2 of adult worms: Dipetalonema viteae, Fasciola hepatica; 3 of eggs: Ascaris suum, Toxocara canis, Schistosoma mansoni; and of Echinococcus granulosus scolices) and against bovine hydatid fluid. Each serum was tested simultaneously at a fixed dilution of 1:160 against all antigens. Extensive cross-reactions were observed, leading to the conclusion that non-purified helminth antigens, even in combination, are of limited value for reliable serodiagnosis in E.L.I.S.A.     

Carnosine-like immunoreactivity in the primary olfactory neuron of the rat

Summary Using the peroxidase-antiperoxidase immunohistochemical technique, carnosine-like immunoreactivity was demonstrated to localize specifically within the primary olfactory neuron.This study was supported by grants from the Ministry of Education, Science and Culture, Japan (No. 61218016). Reprint requests to I. N., Department of Anatomy, School of Medicine, Fujita-Gakuen Health University, Toyoake, Aichi 470-11, Japan.     

Red cell metabolism in red and grey kangaroos

Glucose utilization, lactate production and glutathione regeneration were measured in the red blood cells of 2 species of Australian Marsupials, Eastern grey Kangaroo (Macropus gigantus) and red kangaroo (Macropus rufus), and were found to be significantly lower in the red blood cells from grey than that of red kangaroos.