530 ABNORMALITIES IN METABOLISM 



(1) Occasionally quite typical attacks of uremia are observed with- 

 out high nonprotein nitrogen figures for the blood, even as low as 28 

 mg. having been recorded in a fatal case.^^ 



(2) Extremely high nonprotein nitrogen content may be observed 

 without uremia. Thus Tileston and Comfort found 169 and 150 mg. 

 in two cases of acute intestinal obstruction without uremic symptoms, 

 and similar results have been obtained in bicliloride of mercury pois- 

 oning,^* and mechanical anuria. The occurrence of albuminuric re- 

 tinitis also seems to bear no relation to the nitrogen retention 

 (Woods). 



(3) None of the known nitrogenous constituents of the urine can 

 be held responsible for all the manifestations of typical uremia pois- 

 oning. The highest purine, uric acid and creatinine concentration in 

 a given case may occur entirely independent of uremic couditions,^'^ 

 the amino-nitrogen is not increased in uremia and urea is not sup- 

 posed to be toxic in this degree. To be sure, an unknown toxic sub- 

 stance may be responsible, but in some cases of uremia the total non- 

 protein nitrogen can be accounted for by the known nitrogenous com- 

 ponents found in the blood (Foster). 



We therefore are driven to one of the following alternatives : 



(1) The nerve cells may be made hypersensitive to some one of the 

 known constituents by the excessive amounts of the other metabolites. 

 This is a purely speculative hypothesis, without any actual evidence 

 in its support. 



(2) The portion of unidentified nitrogen usually present in the 

 blood may contain a specific, highly efficient poison. 



In support of this hypothesis is the finding in a series of cases that the pro- 

 portion of noncoaguhible blood nitrogen that couhl not be accounted for by tlie 

 known nitrogenous metabolites seemed to vary directly with the severity of the 

 symptoms (Woods). 35a 



' Ilartnian 3ob has suggested that the substance which causes the characteristic 

 odor of the lu-ine may be responsible for at least some of the intoxication of 

 uremia. This substance, which he has isolated and described under the name 

 "urinod," he believes to be a cyclic ketone with the empirical formula CgHsO; 

 it is highly toxic, and causes mental symptoms. This important observation 

 awaits confirmation. 



Foster s^r has described the finding of a toxic base in the Ijlood of uremics, 

 absent from the blood in other conditions, whicli causes death of guinea pigs with 

 symptoms suggestive of tlie eclamptic type of uremia. Further development of 

 this work is also awaited. 



33 There arc few who would go to tlie extreme of Strauss ( IJerl. kliii. Woch., 

 1915 (.52), .S08) and limit tlie term lu-emia to cases showing a liigli non -protein 

 nitrogen in the blood, no matter wliat the symptomatology and patliology may 

 be. A totally difi"erent view])()int is expressed liy iJeiss, Zeit. klin. Med., 1014 

 (80), 97, 424, 4.')2. 



34 See Foster, Arch. Int. IVfed., l!)ir) (],')), 754. 

 35Mvers and Fine, .Tour. IJiol. Cliein., 1915 (20), :V.n. 

 35a Arch. Int. Med., V.U', (Hi), .-)77, 



sab Ibid., 1915 (Ifi), 9H. 



30c Trans. Assoc. Anier. i'livs., 1!)15 (.'JO), 305. 



