COMPARATIVE STUDIES ON THE METACHROMATIC REACTION OF URINE BY VARIOUS BASIC PIGMENTS

Abstract

In 1953 Nagata and Yamamoto developed the urine metachromatic reaction test (MR), which has since been used mainly for the diagnosis and prognosis of tuberculous disease. According to these investigators, use is made, under their original MR test, of Ziehl's carbol fuchsin solution and 10% formalin solution or 20% sulfosalicylic acid as reagents. On the basis of many studies on the MR, the mechanism underlying the color change of urine is regarded as the metachromagia of basic pigments. A choice was made of 10 basic pigments, including fuchsin. The MR test was done on 159 subjects consisting of 134 patients with urosis and 25 healthy persons and the results were compared with those of the original MR test. The present paper deals with the results thus obtained. Experimental method and material
A) Preliminary experiment
1) Pigments: All the pigments used here was basic pigments. Fuchsin, victoriablue, methyl-violet, cresylblue, anilineblue and brilliantgreen belonged to the triphenylmethan system; toluidine blue and thionine to the thiazine system; red to the azine system; and nileblue to the oxazine system. These ten pigments were specially made by Merk Co., Ltd.
2) Examination of pigments and solvents: Alcohol and water were employed as solvents in an attempt to examine the solubility and chromatic capacity of each pigment.
3) preparation of reagents: On the basis of the original MR test developed by Nagata and Yamamoto, seven saturated solutions of each pigment in 5% carbol at different rates were prepared and used as reagents.
4) Interpretation of MR test results: Using the reagents mentioned under paragraph 3, the MR test was performed on urine specimens of two cases which had positive, doubtful positive and negative results respectively from the original MR test developed by Nagata and Yamamoto. Thus attempts were undertaken to study the macroscopically optimal ratio between each pigment solution and 5% carbol solution.
5) Establishment of criteria for macroscopic interpretation of the results of the MR test in which each pigment solution in 5% carbol was used: According to the method of Nagata and Yamamoto, determination was made of color changes by each pigment solution in urine specimens which were positive, doubtful positive and negative reactions to the MR test.
B) Experiment
The MR test by the use of each pigment solution in 5% carbol: Urine was collected from 134 patients with urosis and 25 healthy persons. The MR test was run on the urine specimens by the use of each pigment solution that was prepared in the preliminary experiment under paragraph 4. The results were interpreted according to macroscopic criteria.
2) Colorimetric determination: Immediately after the MR test was done, colorimetric determination was made of three of the urine specimens, mentioned under paragraph 1, which showed positive, doubtful positive and negative results respectively to the MR test. These were observed by the use of the CIE chromaticity diagram.
Examination of significant differences: Each of the results under paragraph 1 was examine to determine whether there was 8 significant difference. Experimental results
1) The ratio between each pigment solution and 5% carbol was 10:100; that is, the standard ratio used in the original MR test developed by Nagata and Yamamoto was interpreted as optimal.
2) None of the 25 healthy persons showed positive reactions to the MR test in which 10 pigment solutions were used.
3) Of the 134 patients with urosis, 27.6% had positive MR test results in the case of fuchsin solution; 25.4% in the case of nileblue and brilliantgreen; 23.9% in the case of toluidineblue; 23.1% in the case of victoriablue, neutralred and cresylblue; and 22.4% in the case of methylviolet, thionine and anilineblue.
4) Patients with urosis were classified into tuberculous and non-tuberculous, and comparison of the MR test results was made between both groups. In the case of any one of t