394 NELSON W. JANNEY 



in proportion to the degenerative changes found in the thyroid. The ac- 

 companying illustration (Fig. 1, A, B and C) shows an unusual case of 

 the writer's, acromegaly combined with cretinism. 



The thymus has likewise been reported as hypertrophied in hypothy- 

 roidism by some authors, by others (Pineles and B. Kasser) sclerotic with 

 absence of lymphocytes and HassaH's corpuscles. 



Metabolism 



The Gaseous Metabolism in Cretinism and 'Myocedema was first in- 

 vestigated by A. Magnus-Levy (a) in 1895. He discovered the character- 

 istic reduction in the metabolic rate and noted that the gaseous exchange 

 rose again to normal on suitable therapy. For a. long period clinical appli- 

 cations of this important observation failed to be made until the repent 

 respiratory studies of the Americans, E. du Bois, H. Plummer, J. C. 

 Means and J. H. Aub, which have led to the general application of this 

 method. The basal metabolic rate in cretinism and myxedema varies with 

 the severity of the cases and is depressed to as low a level as 40 per cent 

 to 50 per cent in the severest instances. The reduction of the rate is a very 

 constant phenomenon in untreated cases. 



Accompanying the general retardation of chemical changes in the 

 organism, urine is usually excreted in less amount and the total solids are 

 reduced. The total nitrogen output of the urine on a mixed diet is usually 

 lowered as the hypothyroid individual usually fails to ingest as much food 

 as normally. Recent studies by the writer and co-workers have, however, 

 shown that the cretin is unable to retain as large amounts of nitrogen as 

 sound individuals under like conditions. 



With regard to the metabolic derivatives of protein, contradictory state- 

 ments are the rule in the older literature, ''"^These are due in large degree 

 to faulty analytical technique and to the fact that thyroidectomy affects 

 the mature organism less than it does that of the young. According to 

 Pari and the writer's experiments (c), protein destruction takes place 

 at the normal rate in spite of Magnus-Levy's statements to the contrary. 

 Urea and ammonia are excreted in normal proportion to the total nitro- 

 gen and the uric acid is decreased (Jarmey & Isaacson). The metabolism 

 of calcium is much decreased (Hougardy and Langstein). 



Oroatiiiin excretion may be slightly decreased or unchanged. The ab- 

 normal presence of creatin has been reported by McCrudclen, Greenwald 

 and ourselves. These metabolic findings are in general accord with those 

 of other endocrinopathies of a deficiency type so far as investigated. For 

 the effect of thyroid therapy on metabolism, see section Treatment. 



Carbohydrate Metabolism is influenced normally to a considerable ex- 

 tent by the thyroid. Failure of normal thyroid function has been found 



