The equilibrium exchange of [14C]urea and ethylene glycol was measured using a new type of fast flow system. Approximately equal volumes of saline and air were mixed to form a segmented fluid stream into which 14C-loaded red cells are injected. The stream flows through three filter chambers which allow sampling of the 14C in the extracellular fluid at three time points. The chambers are designe...

Treatment of 1-(5-bromo-2-chloro-6-methylpyrimidin-4-yl)-1-methylhydrazine with dimethylthiocarbamoylchloride gave 7-chloro-N,N,1,5-tetramethyl-1H-pyrimido[4,5-e][1,3,4]thiadiazin-3-amine in basic acetonitrile. The latter compounds were reacted with secondary amines in boiling ethanol to afford the related 7-amino derivatives.

investigate its toxicity to the rat. They noted that animals dying after sulphaguanidine showed goitres which on microscopical section were found to be due to hyperplasia and were practically free from colloid. The same effect was produced more or less by other sulpha drugs such as sulphadiazine and sulphapyridine, and Richter and Clisby (1942) showed that other sulphur compounds, notably thiou...

The recent discovery of the rodenticidal properties of a-naphthylthiourea (ANTU) by Richter (1) has aroused interest in the mechanism by which this compound produces its acute toxic effects in animals. Factors associated with the toxicity of ANTU such as (a) the high toxicity to Norway rats, (b) the lower toxicity to most other species, (c) the development of tolerance after administration of s...