426 RETROGRESSIVE CHANGES 



Strada^^ with the nucleoprotein of pus, the so-called pyin, or with 

 chrondroitin-sulphuric acid, did not develop amyloidosis. Oestreich^* 

 injected cancer patients with chondroitin-sulphuric acid for thera- 

 peutic purposes, but no amyloidosis resulted. As it is possible to 

 cause amyloidosis experimentally in animals, especially chickens and 

 rabbits, by causing protracted suppuration or chronic intoxication 

 with bacterial filtrates, these negative results speak strongly against 

 the idea of a transportation of chondroitin-sulphuric acid, but do not 

 determine it finally. They may also, with propriety, be used in sup- 

 port of the statement of Hanssen that amyloid does not contain chon- 

 droitin-sulphuric acid. Leupold"*^ advances the following hypothesis: 

 In chronic suppuration a soluble protein circulates in the blood which 

 stimulates the formation of "defensive ferments." This protein 

 substance, under certain conditions, is deposited in organs where 

 large amounts of sulphuric acid occur. For the development of 

 amyloid there are necessary three factors: A preformed protein, an 

 increased amount of conjugated sulphuric acid, and an inefficiency of 

 the amyloid-filled organ to eliminate the increased amount of conju- 

 gated sulphuric acid. 



There is usually much difficulty in producing amyloid experiment- 

 ally, for in only a certain proportion of cases are the experiments posi- 

 tive (in but about one-third of Davidsohn's'*'* 100 trials, and many 

 other experimenters have been much less successful). ^° Davidsohn, 

 faihng always to get amyloid experimentally after the spleen had been 

 removed, suggests that this organ (in which amyloid is usually earliest 

 and most abundantly observed) produces an enzyme, which causes a 

 precipitation of amyloid in the tissues from a soluble precursor brought 

 in the blood from the site of cell destruction. Schmidt^^ considers it 

 probable that some enzymatic action causes a precipitation or coagula- 

 tion of the substance in the tissue-spaces or lymph-vessels. Amyloid 

 is never deposited in the cells themselves, ^^ and it seems to be now 

 generally considered that the amyloid material is infiltrated in the 

 form of a soluble modification or precursor and that it is not manu- 

 factured in the organ where it is found. It is an interesting fact that 

 a practically identical substance is formed in all tissues and in al 

 species of animals, even when the cause is quite difi"erent. Whether 

 the precursors are brought to the organ in solution, or in leucocytes, is 

 unknown — probably the former. Pollitzer^^ states that in various 

 infections, especially coccus infections, chondroitinsulphuric acid is 

 excreted in the urine; if this is correct it has an undoubted bearing on 



*' Hiochein. Zeit., 1909 (16j, 195. 

 "Zeit. Krebsforsch., 1911 (11), 44. 

 " Verb. Dent. Path. Gesell., 1904 (7), 39. 



»" See Tarclietti, Deut. Arch. klin. Mod., 1903 (75), 526. Hirosc, Bull. Johns 

 Hop. Hosp., 1918 (29), 40. 



*' Verh. Deut. Path. Gesoll., 1904 (7), 2. 



" See Kbert, Virchow's Arch., 1914 (210), 77. 



" Deut. mod. Woeh., 1912 (3S), 1538. 



