60 P-AMINOBENZOIC ACID 



PABA was given by intramuscular injection or by direct application to the 

 scalp. In carefully controlled observations, Brandaleone et al}"^-^^ found 

 PABA to be valueless in treatment of gray hair of human beings. These 

 authors pointed out the difficulty of ascertaining darkening of hair when 

 objective methods are not used. At present, the consensus is that vitamin 

 therapy is ineffective in treatment of ordinary gray hair of human beings. 



2. Dermatology 



According to Strauss et al.,^^' ^° PABA in amounts sufficient to nullify 

 the bacteriostatic effects of sulfathiazole had no beneficial action on rash 

 or fever caused by the latter. Rothman et al.^^ observed that PABA in an 

 ointment base protected the skin against sunburn. Irradiated solutions of 

 PABA caused erythema when injected intradermally, whereas non-ir- 

 radiated solutions did not. A 15 % ointment of PABA protected against 

 fifty to one hundred times the usual erythema dose of ultraviolet light. ^- 

 These findings support the concept that ultraviolet erythema is due in 

 part to photochemical reaction of PABA in the skin. Costello^^ reported a 

 case of vitiligo successfully treated with PABA, which agreed with the 

 findings of Sieve. ^^ 



3. Rickettsial Diseases 



Snyder et al.^"^ first noted that PABA in large doses was effective therapy 

 for experimental rickettsial infections. This was confirmed by Greiff et al.^^ 

 Human tests were first made on twenty cases of typhus fever by Yeomans 

 et al.,^^ who found that when PABA was administered in large doses during 

 the first week of the disease the course was much less severe. Subsequently, 

 these findings have been substantiated in experimental rickettsial infections 

 by Murray et al.,^'' Snyder and Zarafonetis,^^ Hamilton,^^ and Hamilton 



" H. Brandaleone, E. Main, and J. M. Steele, Proc. Soc. Exptl. Biol. Med. 53, 47 

 (1943). 



88 H. Brandaleone, E. Main, and J. M. Steele, Am. J. Med. Sci. 208, 315 (1944). 



89 E. Strauss, F. C. Lowell, and M. Finland, J. Clin. Invest. 20, 189 (1941). 

 9» E. Strauss and M. Finland, Am. J. Med. Sci. 201, 730 (1941). 



91 S. Rothman and J. Rubin, J. Invest. Dermatol. 5, 445 (1942). 



92 S. Rothman and A. B. Henningsen, J. Invest. Dermatol. 9, 307 (1947). 



93 M. Costello, Arch. Dermatol, and Syphilol. 47, 274 (1943). 



9'' J. C. Snyder, J. Maier, and C. R. Anderson, Rept. National Research Council 



Div. Med. Sci., (Dec. 26, 1942), quoted in ref. 2. 

 9s D. Greiff, H. Pinkerton, and V. Moragues, J. Exptl. Med. 80, 561 (1944). 

 96 A. Yeomans, J. C. Snyder, E. S. Murray, C. J. D. Zarafonetis, and R. S. Ecke, 



/. Am. Med. Assoc. 126, 349 (1944). 

 9' E. S. Murray, C. J. D. Zarafonetis, and J. C. Snyder, Proc. Soc. Exptl. Biol. Med. 



60, SO (1945). 



98 J. C. Snyder and C. J. D. Zarafonetis, Proc. Soc. Exptl. Biol. Med. 60, 115 (1945). 



99 H. L. Hamilton, Proc. Soc. Exptl. Biol. Med. 59, 220 (1945). 



