LIPID STORAGE UNDER ABNORMAL CONDITIONS 701 



Pick 919,929 that the pathogenesis of this disease involves a constant removal 

 of sphingomyelin from the circulating blood by the several tissues in which 

 storage of this phospholipid takes place. On the other hand, Thannhauser 

 and Schmidt 922 suggest that the pathogenesis of Niemann-Pick's disease 

 corresponds to that of essential xanthomatosis of the normocholesteremic 

 type. This increased tissue sphingomyelin is believed to result from a de- 

 creased rate of breakdown, due to a disturbance in the intracellular enzymes 

 responsible for the disintegration of this phospholipid, or to an increased 

 rate of synthesis. 



However, neutral fat is greatly increased in the blood. 930 Pick 919 claims 

 that a hypercholesterolemia, as well as a general hyperlipemia, usually 

 occurs. Other workers have not confirmed the fact that hypercholestero- 

 lemia is present. 917,920 



Niemann-Pick's disease is also familial, and has usually been observed in 

 infants. At the onset of the disease, there is loss of appetite, and a corres- 

 ponding decrease in weight results. Death usually occurs between the first 

 and second year. 



c. Tay-Sachs ' Disease (Amaurotic Idiocy, Juvenile Type). This dis- 

 ease corresponds in many respects to Niemann-Pick's disease, but the 

 chemical changes in the brain lipids differ markedly in the two conditions. 

 Sachs, 941 in 1896, was the first to report a "family form of idiocy, generally 

 fatal, associated with early blindness"; the ophthalmological features of 

 the disease were already known, since they had been described fifteen years 

 earlier by Tay. 942 Although certain changes in the retina appeared to be 

 similar in Niemann-Pick's disease and in Tay-Sachs' disease, 930 Rintelen 943 

 found that they differed histologically. Moreover, Thannhauser 917 ob- 

 served that there was no increase in sphingomyelin in the organs of infants 

 suffering from Tay-Sachs' disease, in contradistinction to the marked rise 

 which is observed in Niemann-Pick's disease. 



On examination of the lipids in the brain of infants succumbing to the 

 Tay-Sachs syndrome, Klenk 936,944 and Klenk and Langerbeins 945 reported 

 the presence of a new group of lipids, which was first called "Substance X." 

 These substances were later named "gangliosides." They were found to 

 contain neuraminic acid. 944 - 945 



Although Klenk and Schumann 946 later demonstrated that the ganglio- 



941 B. Sachs, J. Nervous Mental Disease, 21 [n.s.], 475-479 (1896). 



942 W. Tay, Trans. Ophthalmol. Soc. United Kingdom, 1, 55-57 (1881). 



943 F. Rintelen, Arch. Augenheilk., 109, 332-345 (1935-1936). 



944 E. Klenk, Z. physiol. Chem., 26S, 50-58 (1941). 



945 E. Klenk and H. Langerbeins, Z. physiol. Chem., 270, 185-193 (1941). 



946 E. Klenk and E. Schumann, Z. physiol. Chem., 267, 128-144 (1940). 



