106 JOHN T. HALSEY 



implantation experiments have shown that successful grafting almost 

 invariably prevents the development of tetany (or at least lessens its 

 severity in cases where it occurs in spite of the grafting) or, in cases when 

 tetany has already developed, relieves the symptoms or ameliorates their 

 severity. Both in the laboratory and the clinic the effect of administration 

 of preparations of the gland has been exceedingly variable*, but it would 

 appear that at times at least effects are obtained qualitatively similar to 

 those obtained by implantation (vide infra), although quantitatively much 

 less pronounced. The results of post-mortem examination have been rela- 

 tively meager and have contributed to our knowledge in only a moderate 

 degree, but, as far as they go, they are confirmatory of the conclusions 

 reached by other methods. 



Parathyroid therapy has been employed in a. number of conditions 

 and diseases with more or less reported benefit, but here, as elsewhere in 

 the domain of organotherapy, much uncertainty still prevails as to its 

 real value and the correct indications for its application. From various 

 sources there are reports of its more or less successful use in tetany (post- 

 operative and idiopathic), paralysis agitans, eclampsia, epilepsy, and 

 chorea, but it is only in the treatment of tetany that parathyroid therapy 

 rests on a firm and rational basis. 



Tetany. The relationship of parathyroid insufficiency and -tetany 

 having been demonstrated both by the extirpation experiments of various 

 investigators and by clinical observations, the next logical step was the 

 investigation of the effects of the administration of preparations of this 

 gland to parathyroidectomized animals both before and after tetany had 

 resulted. 21 The results obtained by various observers were for the most 

 part disappointing and varied decidedly. In cats, in which tetany had 

 resulted from complete or partial parathyroidectomy, Biedl (quoted by 

 Pineles (b)) could observe no favorable effects from the administration of 

 preparations of this gland, and Pineles, whc administered such prepara- 

 tions, orally, subcutaneously and intraperitoneally had a similar experi- 

 ence, finding that such therapy exerted no favorable influence whatever 

 in the tetany following removal of the parathyroids, MacCallum and 

 Voegtlin (b) and Marine (who gave to their dogs as much as 100 fresh 

 glands per diem) reached the conclusion that the oral administration of 

 parathyroid was useless. On the other hand, a number of other observers 

 have reported that the tetany could be checked by feeding parathyroid or 

 by injection of its extracts (Carlson (#,)). From these experimental 

 studies the conclusion may be drawn that, after complete removal of all 

 parathyroid tissue, the administration (by any route) of parathyroid prep- 



21 In the earlier stages of the study of experimentally induced tetany, at a time 



was believed thai tetany was the result of removal of the thyroids, it was the 



is of the thyroid which were thus administered. Curiously enough certain 



ohst ' CIil1 effects therefrom but the majority obtained only negative 



