582 GASTRO-INTESTIKAL 'AUTOIXTOXICATIOX" 



to SO4. If enough H2S should enter the blood so that it was not 

 completely destroyed, it might well cause harm, for it is decidedly 

 toxic, particularly att'ecting the nervous system; but we have no evi- 

 dence that this often happens. Van der Bergh ^- has observed cases 

 of intestinal obstruction in which the presence of sulphemoglo'bin in 

 the patient's blood was demonstrated. 



Methyl mercaptan, CII3SII, has also been found in the feces, al- 

 though it seems not to be abundantly or constantly present, according 

 to Herter,^^ who found also that mixed bacteria from normal feces 

 rarely produce mercaptan in cultures. However, bacteria from the 

 feces of persons suffering with various diseases often produce mercap- 

 tan. Ethyl mercaptan, CoH-SH, and ethyl sulphide, CoHj-S-CjHj, 

 have also been described as fecal constituents. It is not known that 

 the mercaptans are a cause of intoxication. 



CYSTINE AND CYSTINURIA '■* 



The presence of cystine in the urine has been observed in a num- 

 ber of cases, and when present at all it is usually present in consider- 

 able quantities. Because of its slight solubility it appears as a de- 

 posit of hexagonal crj'stals, and frequently forms cystine concretions 

 (q. V.) in the urinary bladder."'^ According to Garrod it is more 

 common than alkaptonuria, and, like the rest of the "Inborn Errors 

 of Metabolism," occurs much more often in males than in females. 

 Hofmann ^^ was able to collect from the literature to 1907 a total of 

 175 cases, of which 85 were males and 45 females. Baumann and 

 others observed that in cystinuria the urine often contains, besides 

 the cystine, the diamines cadaverine and putrescine, which are formed 

 from lysine and ornithine respectively in the intestines througli putre- 

 faction, and they naturally suspected that cystine arose in the same 

 way. Another view was that the diamines interfered with the oxida- 

 tion of sulphur in the body, so that it was eliminated in the unoxidized 

 form of cystine. But it has been demonstrated that neither of these 

 hypotheses is correct, for (1) cystine could not be found in the feces; 

 (2) if given by mouth, it is completely oxidized, and causes only the 

 appearance of excessive amounts of sulphates in the urine; (3) cys- 

 tinuria has been observed to occur independent of the presence of 

 the diamines, and not to be modified or caused by their administration 

 or pathological formation. The view now prevalent is that the cystine 

 that escapes in the urine in c^-stinuria is not derived from intestinal 



52Deut. Arch. klin. Med., 1905 (S3), SG. 



53 .Tour. Biol. Cliem., 1906 (1), 421. 



54 Literature coneerninfj cystine {,'ivoii l)y Fricdmanii, Kifiohiiissc der Physiol., 

 1902 (I. Aht. 1). If); and l)y Maiui. "Chemistry of the Proteins." jjp. r)()-(i4. Cys- 

 tinuria reviewed l)y I5(')dtker. Zeit. ])hysiol. Chom., 1905 (45), 393; C.arrod, "Inborn 

 Errors of Metaholism," and Lancet, duly, P.tOS. 



5-'> Ahderhaldcn (Zeit. physiol. Chem., 1003 I3S). f).!?) has described a ease in 

 a child in which tlie or^ians were inliJtrated witii masses of tlie cystine crystals. 

 ooCent. Grenz. Med. u. Chir., 1907 (KD. 721. 



