| Popis: |
T HE use of skin re’actions as an aid in clinical diagnosis of many conditions has long been recognized as a valuable proceldure. The Van Pirquet, Schick, Dick reactions and the use of various proteins intradermally for the purpose of detecting allergic sensitivity have all proved their clinical usefulness, There are so many biologic differences between pregnant and nonpregnant individuals that the possibility of being able to differentiate between these groups by means of a skin reaction to some antigen seemed not too remote. Falls and Bartlett,l in 1914, attempted to extract a protein from the placenta which might be used for this purpose. The results were unsatisfactory, due to the fact that the methods employed were not sufficiently refined to yield a pure protein as was hoped, but a mixture of proteins was obtained which led to nonspecific reactions. By using better methods of extraction and preparation of the placental proteins, Cohen and Freda attempted to produce precipitin reactions and specific skin reactions that might be useful diagnostically. When the precipitin reaction was tried, serum of known pregnant women reacted positively in about 7.5 per cent of the cases. The serum of males a,ud normal females did not react. Certain nonpregnant women with gynecologic pathology gave a rather high percentage of false positive reactions which nullified the usefulness of this method for practical diagnostic purposes. The use of placental tissue extracts in producing skin reactions was to some extent successful, since about 75 per cent of the patients tested by intradermal injections gave positive reactions if pregnancy existed and negative if no pregnancy were present. This result was in accord with the results reported by Esch,” Englehorn and Wintz,4 Gruskin5 and Schwartz6 who made similar tests have reported a higher percentage of correct diagnosis. The high percentage of false reactions (25 per cent) rendered the use of these procedures for diagnostic purposes useless, and so it was decided to try to find an antigen that would give more specific reactions. The possibility of using proteins extracted from breast tissue was suggested, since it was thought that during pregnancy the cells of the breast might secrete a protein of somewhat different compositiou than other body proteins. On further consideration this idea was rejected in favor of using colostrum which must contain the proteins produced by the breast in early pregnancy. By using this material the contamination of |
