July 30, 1915] 



SCIENCE 



143 



proteid nitrogen of the plasma shows a 

 slight rise on the first day in every case 

 studied, and a tendency to rise, with some 

 fluctuations, as the process is continued. 

 This increase, which is chiefly due to urea, 

 may be due either to an increase in nitro- 



Flasmapheresis on Three Dogs for Several Days. 



Nos. S and 11 Three Days Each, No. 10 



Two Days 



genous katabolism or to a diminution of 

 nitrogen excretion. 



Studies have also been made of blood 

 pressure and blood counts. Plasmapheresis, 

 like hemorrhage, causes a seemingly para- 

 doxical increase in the number of red cells 

 per unit volume of blood. This, which ap- 

 pears to be a general phenomenon accom- 

 panying temporary asphyxia, is being in- 

 vestigated in all its bearings by Dr. 

 Lamson.i* The blood pressure, which falls 

 on bleeding, is restored to a satisfactory 

 value on returning the corpuscles and, for a 

 long period the two changes may nearly 

 compensate each other. A slight downward 

 tendency is noticed, however, as plasma- 

 pheresis is continued, and in the end a 

 dangerously low point (about 50 mm.) will 

 be reached on withdrawing amounts of 

 blood considerably smaller than those taken 

 at the start. The previous bleeding usually 

 shows a fall to a point (from 60 to 80 mm.) 

 which should be regarded as a warning, 

 even though 100 mm. or more may be 

 reached on reinjection. 



The following tables give in condensed 

 form some of the data to which reference 

 has been made in the foregoing pages. 



TABLE II 



Chemical Analyses. Plasmapheresis for one day, on three dogs 



Weight of dog 



Blood volume estimated at 7.5^ 



Total volume bled and % of total blood 



Number of bleedings 



Eesults of analyses, percentages 



Total protein of blood . 



Protein of plasma 



Difference of above" 



Blood counts, millions . 

 Total non-proteid N .... 



Urea nitrogen 



Non-urea nitrogen 



Aminonitrogen 



Dee. 21 



15.1kg. 



1,132 c.c. 



1,185 cc. =105% 



3 

 Before After 

 plasmapheresis 

 22.27 25.23 



6.62 

 15.65 

 9.0 

 0.037 

 0.016 

 0.021 

 0.0041 



3.63 

 21.60 

 11.7 

 0.039 

 0.019 

 0.020 



.11 



11.9 kg. 



892 c.c. 



1,150 cc =129% 



3 

 Before After 

 'esis 

 25.32 

 3.17 

 22.15 

 12.9 

 0.036 

 0.017 

 0.021 



25.15 

 6.59 



18.56 



11.8 

 0.029 

 0.011 

 0.018 



Jan. 18 



7.1 kg. 



532 cc 



410 c.c. =77% 



5 

 Before After 

 plasmapheresis 

 17.34 17.19 

 6.28 3.68 



11.06 13.51 



6.6 



0.045 



0.016 



0.029 



0.0048 



7.5 



0.055 



0.023 



0.032 



0.0048 



14 " Polycythemia, " P. D. Lamson, Jour. Pharm. and Expt. Ther., VIL, No. 1, July, 1915. 



15 Blood taken for analysis not included unless made up by equal amount of washed corpuscles 

 from other dogs. 



