576 SAMUEL H. HURWITZ 



effect of hemorrhage on protein metabolism in the secondary anemias in 

 man. These discordant results may be due, in part at least, to the differ- 

 ence in the effects produced by external and by internal hemorrhage upon 

 nitrogen excretion. 



Ascoli and Draghi, in a study of five patients following the removal 

 of from 200 to 500 c.c. of blood, found evidences of increased rather than 

 decreased protein catabolism in three of the five patients. Their results 

 have been criticized, however, because of the abnormality of the subjects, 

 the inadequate control of the food intake, and the shortness of the periods 

 of observation. Strauss (e), on the other hand, studied the effects of blood- 

 letting (150 to 200 c.c.) upon the metabolism of individuals in nitrogen 

 equilibrium. None of the four patients observed by him showed any 

 increase in nitrogen output as a consequence of the withdrawal of blood. 

 However, in four out of seven patients with gastric hemorrhage he found 

 high values for nitrogen in the urine. This finding is opposed to the 

 view of von Xoorden, who failed to find a greater excretion of nitrogen, 

 either on the day of the hemorrhage, or on the days immediately suc- 

 ceeding it. That certain internal hemorrhages may at times be associated 

 with an increase in the elimination of nitrogen appears probable from the 

 work of some investigators, who attribute the high numerical values for 

 nitrogen in the urine of patients with gastric hemorrhage, to the absorption 

 and decomposition of large quantities of blood in the intestine (Strauss). 



The results of studies on the nitrogen metabolism of patients with 

 chlorosis are less conflicting. The view held by von Noorden that 

 protein metabolism is practically normal in ordinary cases of chlorosis has 

 received support from the experimental work of the majority of in- 

 vestigators, more particularly of Vamiini, who found only a slight 

 retention of nitrogen in three instances, approximate nitrogenous equi- 

 librium in one instance, and a slight nitrogen loss in another instance. 

 These metabolic studies on chlorotic patients do not support the view 

 that chlorosis is due to the action of some toxic factor, inasmuch as the 

 effect of such an agent usually is to destroy tissue protein, which would 

 be indicated by a nitrogen loss. 



In the anemia of Banti's disease Umber (&) demonstrated a patho- 

 logical decomposition of protein, which, because of its disappearance 

 following splenectomy, he attributed to a toxic agent produced in the 

 diseased spleen. According to this worker, the same toxic factor produced 

 both the anemia and the metabolic changes observed. Other investigators 

 (Miiller(a.), Luce, Lommel(c), Grosser), however, have failed to confirm 

 this observation. , 



A number of studies have been made on the protein metabolism in the 

 hemolytic anemias of known and unknown etiology. Von Noorden(a) 

 (6)(rf) was the first to carry out accurate observations on the protein 

 decomposition in pernicious anemia. His experiments, in which the 



