PATHOLOGICAL METABOLISM OF THE BLOOD 577 



essential requirements for careful metabolic work were fulfilled, do not 

 support the findings of some of the earlier investigators, who report a 

 pathological destruction of protein in this disease. Von Noorden found, 

 on the contrary, that some of the patients may show a tendency to retain 

 nitrogen. H(is conclusions have, in the main, received support from the 

 subsequent contributions of von Stejskal and Erbn(6), Strauss, Halpern, 

 and Bloch. In an experiment extending over six days, Bloch found in one 

 patient with pernicious anemia a retention of nitrogen amounting to 3.08 

 grams per day on an intake of 17.8 grams, and in another instance, a 

 retention of 1.08 grams on an intake of 17.23 grams of nitrogen. Positive 

 nitrogen balances of this grade may be attributed either to previous under- 

 nutrition (Bernert and von Steyskal), or what is more likely in these 

 particular instances, to forced protein feeding, which as Mosenthal(^) 

 has pointed out, may lead to the increased assimilation of nitrogen in 

 patients with pernicio.us anemia. 



Minot(a), on the other hand, in a study of the nitrogen metabolism in 

 pernicious anemia before and after splenectomy, reports an average daily 

 nitrogen loss of 0.78 gram before and a slightly positive balance of 0.6 

 gram after operation. This conversion of a negative into a positive nitro- 

 gen balance in pernicious anemia has not been confirmed by Pepper and 

 Austin (c). These workers found the nitrogen balance slightly positive 

 both before and after splenectomy. 



Rosenqvist, who carried out extensive studies on the protein metab- 

 olism in pernicious and dibothriocephalus anemia obtained results which 

 are to some extent opposed to those of other investigators. He found 

 considerable fluctuation in the nitrogen balance in pernicious anemia, 

 periods of increased nitrogen loss alternating with periods of nitrogen 

 retention. Interesting in this connection is the observation of Rosenqvist 

 that some of the eighteen patients with bothriocephalus anemia studied 

 showed a well-marked loss of nitrogen only during the presence of the 

 tapeworm in the body, whereas after its extrusion, a retention of nitrogen 

 was usually demonstrable. 



Strauss and Umber have suggested that the fluctuations in the nitrogen 

 balance noted by Rosenqvist might have been due to the employment of 

 faulty methods, as well as to functional disturbances .of a temporary 

 nature in the alimentary tract and in the kidneys. It is not unlikely 

 that a severe anemia might lead to variations in the amount of material 

 absorbed per day, and in certain instances, more or less protracted dis- 

 turbances of renal function may result from the anemia, which would 

 give rise to irregularities in the excretion of nitrogen such as are some- 

 times found in patients suffering from renal disease (Christian). 



The nitrogen metabolism in congenital hemolytic icterus has been 

 studied by McKelvy and Rosenbloom, and by Goldschmidt, Pepper and 

 Pearce. During a period of five days the former workers found a loss of 



