quent works, Palladin made a detailed study of age-associated changes in a 

 number of biochemical indices in mammalian tissues and at the same time con- 

 ducted his investigations on a broad plane of comparative biochemistry. 



Specifically, Palladin developed the biochemistry of the age-associated 

 development of organisms and also concerned himself with the problems of the 

 general theory of aging (1923). 



Palladin has been studying very diligently the age-associated changes in the 

 enzymatic properties of tissues and organs and the small details of the inter- 

 mediate metabolism of proteins and carbohydrates. In recent years, the central 

 orientation of Palladin's research has been the comparative biochemical study 

 of the protein and nucleotide metabolism of the central nervous system. Par- 

 ticular attention has been paid to the age-linked biochemistry of the brain (and 

 especially its embryochemistry). In Palladin's school of functional biochemistry 

 of the brain, ontobiochemical investigations occupy an important place. 



Among A. V. Palladin's pupils, who have done a great deal for the develop- 

 ment of age-associated biochemistry, we must mention D. L. Ferdman, A. M. 

 Utevskiy, L. I. Palladina, Ye. S. Savron', L. Ye. Rozenfeld', and many others. 



The biochemistry and metabolic characteristics of childhood have been 

 studied and are still being studied by O. P. Molchanova (1935-1948) and N. P. 

 Tolkachevskaya (1939-1954). The latter, together with her co-workers, has 

 made a particularly detailed investigation of gas exchange and protein and 

 carbohydrate metabolism in young children. 



Extensive investigations in the area of pediatrics, and particularly in the 

 physiology of childhood, have been conducted in the laboratories of G. N. 

 Speranskiy (1914-1945) and A. F. Tur (1927-1947). The work of V. G. 

 Shtefko and his pupils (1924-1946) was devoted to the morphophysiology of 

 early ontogenesis. 



A great deal of work was done in the field of biochemistry of phylogenesis 

 and ontogenesis of plants by A. B. Blagoveshchenskiy (1935). He believed that 

 a tendency to cyclization, i.e., replacement of organic compounds with an 

 open carbohydrate [tr. : sic] ring by compounds with a closed ring, is one of the 

 basic mechanisms of both the phylogenesis and ontogenesis of plants. In this 

 way, he formulated in a changed form the view of A. Pictet that in ontogenesis 

 there is a gradual replacement of the more reactive and higher energy aliphatic 

 compounds by less reactive and lower energy cyclic compounds. The age- 

 associated cyclization of substances is one of the manifestations of an increase 

 in entropic processes during the period of old age. 



It must be noted that the theory of cyclization (as it was developed by A. 

 Pictet) cannot be regarded as acceptable. A strong criticism of this theory 

 was advanced by A. V. Nagorniy (1940): "Inasmuch as cyclic compounds con- 

 tain less free energy than acyclic ones, the transformation of the latter into the 

 former in closed systems is a natural spontaneous process. Since the living 

 organism is an open system, subject to the unceasing processes of matter and 

 energy metabolism, it is entirely clear that the processes of cyclization cannot 

 be primary but are only a reflection of certain characteristics of the metabolism 

 and subordinate to them. 



29 



