Serum Hepatitis Presenting as Sudden Loss of Consciousness

Abstract

Erythropoietin in Urine-Finne MEDICAL JOURNAL 699 will give a better idea of the degree of humoral stimulation of erythropoiesis than measuring the plasma erythropoietin level.When we want to compare from one laboratory to another the amount of erythropoietin found in the urine in different diseases, the method of concentration must be taken into consideration. The simple way of concentration by freezedrying after dialysis must be regarded as less destructive than precipitation or boiling. With these last methods a loss of erythropoietin may be suspected during the different procedures, although the end-product may be a more concentrated and pure one. However, so long as the only means of assaying the erythropoietin is by its biological activity and not by chemical quantitation, the easy way of concentration by dialysis and freeze-drying is most suitable for the purpose of quantitating urinary erythropoietin excretion.As the amount of erythropoietin excreted under physiological conditions is as high as is shown in Table II, the discrimination between persons with different levels of erythropoietin excretion would be easier if the concentrates were divided in smaller doses than used in the present study-that is, injected into a greater number of mice-because the maximum response to erythropoietin is obtained with about 6-8 units per mouse (DeGowin et al., 1962). The contrary would be the case in persons with lowered erythropoietin excretion.When measuring the amount of erythropoietin excreted in the urine the sensitivity of the assay method should be shown by a calibration curve using "standard erythropoietin." In this way the 24-hour erythropoietin excretion could be given in "standard units."The demonstration of erythropoietin in normal amniotic fluid must be taken to be in favour of the hypothesis that erythropoiesis is regulated through erythropoietin antenatally as well. It is also likely that erythropoietin in the amniotic fluid is derived from the urine, since previous investigations have shown that in anaemic foetuses erythropoietin may be excreted in the urine (Finne, 1964