174 PATHOLOGY OF PURIN METABOLISM 



tion remaining: that in some way and from some cause the 

 excretion of uric acid is itself at fault. 



Curve of Uric Acid Excretion in Acute Gouty Exacerba- 

 tions. In review of the literature of gout two groups of phe- 

 nomena (apparently beyond question of doubt) stand out 

 prominently, which may be held to indicate that faults of 

 excretion play an actually important part in the pathology of 

 gout. These are the characteristic curve of urinary excre- 

 tion of uric acid in acute gouty exacerbations and the fact of 

 the delayed transformation of nucleins in the gouty subject. 



Primarily, in reference to the first of these features, 

 Friedrich Umber may be cited as a clinical witness. This 

 authority says in his valuable text-book upon nutrition and 

 the diseases of metabolism: "The curve of uric acid excre- 

 tion in the gouty subject on purin-free diet is so character- 

 istic in the periods of exacerbation as to be of distinctly 

 pathognomonic value. The essential endogenous curve of 

 uric acid sinks, as His has pointed out, immediately before 

 the paroxysm to a still lower level (which I may speak of 

 as an anacritical stage of depression), to quickly increase 

 as soon as the paroxysm has begun (auric acid wave, accord- 

 ing to E. Pfeiffer, who first observed this point), and reaches 

 its acme on the second or third day; after which with the 

 gradual disappearance of the gouty paroxysm it again sinks 

 into a second or postcritical stage of depression succeeding 

 the paroxysm. . . * This course of the endogenous purin 

 curve may, it is true, . . . be modified by frequently 

 recurring gouty exacerbations ; but aside from this it is of 

 decided significance as a feature in differential diagnosis. " 6 



Delayed Nuclein Exchange in the Gouty. Along with 

 this fact of the damming back of the uric acid and its break- 

 ing through the dam in some degree in the acute paroxysms 



F. Umber, Lehrb. d. Ernahrung u. d. Stoffwechselkrankheiten, p. 269, 

 Berlin and Vienna, Urban and Schwarzenberg, 1909. 



