XI. PATHOLOGY 501 



blood of pernicious anemia patients under treatment with B12, purified 

 liver extracts, or PGA. The change in the physical properties of the cells 

 was attributed to the presence of an abnormal form of hemoglobin. 

 Owren^^'*^ supports Larsen's hypothesis concerning such abnormal hemo- 

 globin and believes that the defect lies in the protein rather than the heme 

 portion of the molecule. The metabolic dysfunction, which may be cor- 

 rected by crude liver extracts but not, according to Owren, by purified 

 liver extracts, B12, or PGA, involves protein synthesis within the liver and 

 results not only in the production of an abnormal hemoglobin but also in 

 a decreased formation of prothrombin as measured bj^ Owren's technique. 



Whether or not the claims of Larsen and Owren with respect to the superi- 

 ority of crude liver extracts over purified extracts and B12 ultimately re- 

 ceive support from other investigators, the fact remains that purified liver 

 extracts have been used extensively in the treatment of pernicious anemia 

 ever since their introduction in the mid-nineteen thirties, and the con- 

 census of almost all clinicians is that such preparations provide complete 

 remission as evidenced by relief of clinical manifestations and restoration 

 to normal of all of the usually determined hematologic values. In the words 

 of Wm. P. Murphy, "There is much evidence available to confirm the 

 beneficial effect of the concentrated extracts on all of the disturbances 

 characteristic of pernicious anemia including those due to neural damage. 

 No evidence has been presented to show that 'crude' extracts are more 

 beneficial in anj^ respect."" 



Of the several analogs of vitamin Bio which have been isolated and made 

 available for clinical trial, none has been shown to differ in therapeutic 

 properties or degree of effectiveness from B12 itself (cyanocobalamin).^-- *^'^^ 

 However, it seems likely that quantitative differences in potency among 

 the cobalamin analogs will be detected as their use continues. 



4. Fish Tapeworm Infestation 



Megaloblastic anemia associated with fish tapeworm (Diphijlloboihrium 

 latum) infestation has been shown to be a true Bi2 deficiency state. Earlier, 



" P. A. Owren, Scand. J. Clin. Lab. Invest. 2, 241 (1950). 



"* P. A. Owren, Proc. Srd Intern. Congr. Haematol. Cambridge, England, 1950, Grune 



& Stratton, New York, p. 22, 1951. 

 ** P. A. Owren, Proc. Srd Intern. Congr. Haematol. Cambridge, England, 1950, Grune 



& Stratton, Xew York, p. 34, 1951. 

 " W. P. Murphy, Blood 3, 32 (1948). 

 " H. Lichtman, J. Watson, V. Ginsberg, J. V. Pierce, E. L. R. Stokstad, and T. H. 



Jukes, Proc. Soc. Expll. Biol. Med. 72, 643 (1949). 

 " R. F. Schilling, J. W. Harris, and W. B. Castle, Blood 6, 228 (1951). 

 60 C. C. Ungley and H. Campbell, Brit. Med. J. I, 152 (1951). 

 6' J. X. M. Chalmers, Brit. Med .J. I, 161 (1951). 

 6== G. C. K. Reid, Brit. Med. J. I, 164 (1951). 

 «' G. W. James, III, and L. D. Abbott, Jr., Proc. Soc. Expll. Biol. Med. 77, 416 (1951). 



