CHOLITRIA.
Definition.—Choluria is a morbid con dition of the urine observed in jaundice and characterized by the presence in it of the constituents of the gall, especially the bile-pigments and the bile-acids.
In urobilinuria the normal constitu ents of the bile are not found in the urine, but a derivative of the bile-pig ments—the urobilin—is found instead.
Symptoms.—Although the bile-acids are ordinarily present in the urine in choluria, they do not occasion character istic symptoms, and can only be revealed by special tests. The presence of the bile is more easily detected.
The urine containing bilirubin exhib its a color varying from a light saffron yellow to one resembling mahogany or porter; even when the color is dark brown. or almost black the urine will show a tinge of olive-green or green brown when it is seen in thin strata. The color of the -urine may resemble that of a very concentrated urine or of urine con taining blood; in the later cases the froth of the urine is white, while the froth of the icteric urine is yellow and tinges white a piece of linen or blotting-paper dipped into it.
On standing, icteric urine ordinarily becomes g,reenish, because the bilirubin, by oxidizing, changes into biliverdin; by further decomposition of the urine the pigments are further changed into bili prasin and bilifuscin.
Although cholesterin is a normal con stituent of the bile, it is not found in the urine in choluria, but in other morbid conditions of the urine: e.g., chyluria.
In some eases of eboluria renal cast observed in the urine without albumi nuria. Nothnag,e1 (Deut. Arehiv f. klin.
Med., xiii, p. 4S7).
Diagnosis. — Different remedies may oive the urine a color resemblinff that observed in choluria. When santonin, thallin, rhubarb, or picric acid have been ingested, the urine and its froth will pre sent a yellow color. In poisoning with the fruit of Cytissus laburnum a dark green color of the urine is observed, whereas it is blue-green after the inges tion of methylene-blue. The presence of the bile-pigments are revealed by differ ent tests.
1. Gmelin's test consists in bringing strong nitric acid containing some ni trous acid in contact with the urine; if bile be present, a play of color is devel oped from green to blue, violet, and finally red. These changes are due to
the gradual oxidation of the bile-pig ments. The green color is the most char acteristic, being dependent on the forma tion of biliverdin. It must be remem bered that in most urines a reddish. tint is brought out by nitric acid, while, if much indican is present, a blue or violet color may be developed.
Gmelin's test is best performed by pouring a few cubic centimetres of nitric acid in a test-tube or a conical glass; the urine is then allowed to flow gently so as to cause it to fall on the surface of the acid. The play of color is then observed at the junction of the liquids. The urine may also be placed in the tube first and the acid poured in gradually so that it sinks down to the bottom. Only the green color is evidence for the presence of bile-pigment, since the other colors may be due to the action of the acid upon the normal urine-pigments. The presence of albumin is of no consequence; the green color is even more visible against the white albuminous deposit. Gmelin's test has been modified in dif ferent ways.
Rosenbach proposes to filter the urine through white blotting-paper and place a drop of nitric acid on the filter 1-vhile still moist; or a drop of the urine and of the acid are placed separately on a white porcelain surface and allowed to come in contact. In both cases the characteristic color-rings will appear.
Gmelin's test is very reliable when the quantity of bile-pigments is not too small; when this is the case, however, it is necessary to isolate the pigment by gently shaking the urine with chloro form; this agent will dissolve the bili rubin and cause a yellow color. When the test-tube is left quiet for some min utes the chloroform solution of bilirubin will sink to the bottom, the urine can be poured out, and the test performed with the chloroform solution. Indican is not dissolved by chloroform.