Fractionation of Erythropoietin by Selective Membrane Permeability

Hemoglobin C in Newborn Sheep and Goats: A Possible Explanation for its Function and Biosynthesis

“…The method used for determining the ESF activity of serum was a modification of the technique described by PAVLOVIC-KENTERA et al [38]. This modification, which uses a n oxygen-nitrogen mixture with 8 % 0, to produce polycythemia in assay mice, has been described elsewhere [33]. …”

The Selective Inactivation of an ESF-Generating Factor (EGF) in the Presence of Erythropoietin (ESF)

“…The urine was obtained from one patient with paroxysmal nocturnal hemoglobinuria (PNH) and from a preterminal patient with an anemia secondary to multiple myeloma (MM). Fraction I1 + I11 was fractionated further by selective membrane permeability (9)(10)(11)(12)16). The dialysates and retentates were then .dialyzed in 24/32-in.…”

The Selective Membrane Filtration of an ESF-generating Factor (EGF) in the Presence of Erythropoietin (ESF)

“…An ESF was removed from fraction I1 + I11 by selective membrane permeability (9)(10)(11)(12)(13). The retentates, after exhaustive dialysis and lyophilization, were dissolved in 0.02 M phosphate buffer at pH 7.4 and 0.5 M NaCl and fractionated by selective membrane filtration with Amicon XM-50 centriflo membranes supported in 50-ml conical centrifuge tubes.…”

“…The volumes of the solutions were adjusted so as to contain the extract from 0.05 or 0.20 mg of the fractions/ml, respectively, from the urines of the MM and PNH patients. ESF and generated ESF activity were determined on all fractions (9)(10)(11)(12)15). The posthypoxic-polycythemic mouse was used as an assay animal for ESF activity (15).…”

“…The EGF activity was pH dependent, whereas the ESF activity was not. The pH-ESF activity data were obtained on the fractions as reported (10)(11)(12). The EGF was inactivated with 10 llJM of dithiothreitol (DTT), whereas the ESF was not (13).…”