Melatonin antagonizes colchicine-induced mitotic arrest

Summary Melatonin, in concentrations up to 10^–3 M, showed no effect on mitosis in cultures of HeLa or KB cells. However, when melatonin at 10^–4 M was preincubated with HeLa cells prior to addition of 10^–7 M colchicine, a reduction in the mitotic index, in comparison to colchicine alone, was observed.This work was supported by PHS Grant No. CA 16425.     

Radiation-released histamine in the rhesus monkey as modified by mast-cell depletion and antihistamine

Summary 4000 rads of mixed gamma neutron radiation administered to rhesus monkeys released a significant amount of histamine into their circulation. When the monkeys were treated with a mast-cell histamine depleter (compound 48/80) for 4 days and then irradiated, no increase in circulating histamine was seen. When 48/80 was given 20 min after irradiation, only a slight increase in histamine was seen, indicating that 4000 rads had released most of the mast-cell histamine.     

Shwartzman phenomenon without endotoxin preparation

Zusammenfassung Kasein, Pepton bzw. Baktokasiton wurde als präparierende Erstinjektion für lokalisiertes Shwartzman-Phänomen an Kaninchen verwendet. Nach provozierender i.v. Endotoxininjektion kommt es zum typischen Shwartzman-Phänomen. Da die verwendeten Substanzen Chemotaxis von Leukozyten verursachen, ist anzunehmen, dass die an Stelle der präparierenden Injektion angesammelten Leukozyten in der Ausbildung des Shwartzman-Phänomens eine vorwiegende Rolle spielen.