| Abstract: | For the past few years, we have been engaged
in isolating and separating middle molecules (MMs)
from biologic fluids of healthy persons and uremic
patients. Plasma or serum, ultrafiltrate, and peri-
toneal outflow dialysate from uremic patients, as
well as plasma from healthy subjects, were fractionat-
ed by gel chromatography. Plasma or serum was
pretreated with a 40 x l cm Sephadex G 50 column
or by CXA ultrafilter. Fractionation of MMs was
performed on a 100 x I cm Sephadex G 15 column,
eluted with NH.HCO:} buffer. UV absorbance was
measured at 206 nm, 225 nm, or both.
All samples could be separated into about 10
peaks according to elution volume. Peak 2 and peak
3, corresponding to the elution volumes for vitamin
B12 and oxytocin, were significantly higher in uremic
than healthy sera. These two peaks were regarded
as the main fractions containing uremic MMs.
MMs measurement was used to: a) evaluate the
efficiency of various dialyzers and hemoperfusion,
b) evaluate the efficacy of continuous ambulatory
peritoneal dialysis (CAPD) and hemodialysis (HD)
in the removal of MMs, c) calculate the total quan
tity of MMs removed by CAPD, intermittent peri-
toneal dialysis and ultrafiltration, and d) assess the
efficacy of reused dialyzers.
Subfractionation of MMs by thin layer finger
prints technic was carried out. Identification of the
separated substances is in progress. |
