BIOLOGY IN HUMAN AFFAIRS 



In the condition known as pernicious anemia there is a 

 deficiency in the number and a change in the character of 

 red blood cells. A lessened number of cells may be due to 

 the fact that they are being destroyed too rapidly or to the 

 fact that they are not being created sufficiently rapidly 

 and in sufficient quantities. In pernicious anemia, their 

 number decreases so rapidly and stays so low that it threat- 

 ens life itself. The number of red blood cells may fall to 

 1,000,000 or 1,200,000, instead of the 4,000,000 to 5,000,000 

 that represent the normal condition. 



One of the greatest finds of recent times was the dis- 

 covery that the liver contains a substance which has the 

 specific power of raising the number of red blood cells, 

 apparently by stimulating the production of red cells in 

 the places in the body where they are produced, notably 

 in the bone marrow. Concentrated extracts have been 

 developed which cause rapid formation of the cells; and a 

 fatal termination to pernicious anemia, which was form- 

 erly inevitable, is no longer feared. Moreover, continued 

 investigation now shows that there are substances also 

 in the wall of the stomach and in the muscles which have 

 this specific power. 



Obviously, only the frontier of this unknown land has 

 been invaded. Much more needs to be known as to the 

 nature of the red blood cell, its method of formation, 

 the materials from which it is formed, and the factors 

 governing its formation, growth, and destruction. It 

 probably has something to do with the ability of the body 

 to resist the invasion of foreign substances. At all events, 

 the red blood cells can be sensitized in such a way that 

 they will clump together or will dissolve when certain sub- 

 stances of bacterial or other foreign origin are injected into 

 the body; and obviously, if such reactions occur, the result 

 to the patient's health and life is serious. The materials 

 used in the treatment of pernicious anemia must also be 



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