The Biology of Senescence 



(1668-1 738), who 'recommended an old Burgomaster of Amster- 

 dam to lie between two young girls, assuring him that he would 

 thus recover strength and spirits', Hufeland (1798) remarks 'We 

 cannot refuse our approval to the method.' It would seem by 

 tradition to be applicable only to the male. 



44 Progeria 



Although the rate of senile deterioration varies between indi- 

 viduals, the specific age of genetically homogeneous animal 

 lines is very stable; even in human populations the range of 

 apparent variation is not very great, and the few descriptions 

 of racially-distributed 'premature senility', as in Eskimos 

 (Brown, Sinclair, Cronk and Clark, 1948) are not actuarially 

 supported, though such variation, genetic or environmental, 

 may occur. 



Sporadic cases of syndromes having some of the general char- 

 acters of premature old age occasionally occur in man. It is not 

 clear how far any of these syndromes can be regarded as 

 genuine accelerations of the timing mechanisms which deter- 

 mines senescence. They are apparently pleiotropic genetic de- 

 fects, occurring commonly in sibs, and are most conveniently 

 mentioned here. They have been regarded as pluriglandular 

 endocrine disturbances, but they affect many ectodermal struc- 

 tures and have the rather generalized character more typical of 

 an inborn error of metabolism — possibly the deficiency of an 

 enzyme system. 



Infantile progeria (Hutchinson- Gilford syndrome) (Thomson 

 and Forfar, 1950; Manschot, 1940, 1950) occurs in childhood. 

 After an apparently normal infancy, the child begins to show 

 retarded growth, with dwarfism and progressively increasing 

 physical abnormality. The appearance becomes senile, the skin 

 atrophic, and there is hypertension with extensive atheroma 

 and calcification. Death usually occurs from coronary disease 

 before the thirtieth year. The mental development of these 

 children may be retarded, but is more typically precocious. 

 Cataract may occur. The endocrine appearances at necropsy 

 are inconstant, but pituitary eosinophiles are reported to be 

 reduced (Manschot, 1940). 



134 



