[Comparative experiments on erythropoietin concentrations in ultrafiltered urine (Diaflo-process) and urine dialysis with higher osmolar substances (Carbowax( (author's transl)].

The Diaflo-ultrafiltration process with polyion membranes, UM 10, PM 10, and PM 30 for the determination of erythropoietin concentration in urine is compared with the method of urine dialysis in Visking tubes against Carbowax. The aberage regain of animal erythropoietin in human urine by ultrafiltration with the UM 10-membrane is 84%, with the PM 10-membrane 62%,with the PM 30-membrane 17% and with urine dialysis 71%. Mice show a lower toleration for the UM 10 concentrates than for the concentrates prepared by urine dialysis. The concentrates of kidney patients also cause a higher mortality in the animals. The concentrates are tolerated when equal amounts of urine components are incorporated in a three times larger volume and this is divided into three separate injections. Mice with polyglobulia tolerate urine concentrates when not more than 6% of a whole contrate of a 24-hours-urine per mouse is injected in the peritoneum. There is a low iron incorporation rate in the mice that show a strongly toxic reaction.