Non-protein Nitrogen of the Blood in Nephritis. 169 



nine. In two similar experiments with creatinine, there was 

 apparently a slight increase in the creatine (total creatinine) con- 

 centration of the muscle, which we are not prepared to discuss at 

 this time. 



The possible influence of autolysis upon the content of muscle 

 creatine and added creatine and creatinine is being investigated. 



106 (802) 



The total non-protein nitrogen of the blood in nephritis and allied 



conditions. 



By Clifford B. Farr, M.D., and J. Harold Austin, M.D. 



[From the John Herr Musser Department of Research Medicine, 

 University of Pennsylvania, Philadelphia.] 



The following summary covers the results of our study of the 

 non-protein nitrogen of the blood by Folin's methods in a series 

 of fifty-nine hospital patients. Our main concern has been with 

 nephritis but we have examined the blood in many other conditions 

 as opportunity offered. 



The patients group themselves into four divisions: 

 I. Those showing no disturbance of renal function (17 cases). 

 II. Those with marked cardio-vascular disease of some type, 

 most of which showed urinary changes the result of renal 

 congestion (11 cases). 



III. Those showing nephritis (23 cases). 



IV. Those in which certain features would lead one to suspect 



nephritis, but in which the existence of nephritis is not 



borne out by other findings (8 cases). 

 Our patients of Group I, suffering from a variety of acute 

 and chronic diseases, but without evidence of disturbance of renal 

 function, showed a total non-protein nitrogen in the blood varying 

 from 16 to 43 milligrams per 100 c.c. From 50 to 60 per cent, of 

 this was in the ammonia-urea fraction. In the patients with 

 cardio-vascular disease with renal congestion, but without evidence 

 of other renal lesion there was no increase of the non-protein 

 nitrogen in the blood, nor alteration of the ammonia-urea per- 

 centage, although albuminuria, casts and some impairment of the 

 phenolsulphonephthalein elimination were usually present. 



