Mastic Reaction

Mastic Reaction belongs to the type of colloidal reactions introduced at various times into the clinic of nervous diseases for the examination of cerebrospinal fluid. The M. r. is based on the principle of the protective action of colloids (albumins) of normal cerebrospinal fluid, which prevents the colloidal solution of mastic from precipitating in a certain electrolyte medium. On the basis of this principle, the reaction should proceed in a solution of electrolyte that precipitates (without the addition of cerebrospinal fluid) mastic. Pathologically altered cerebrospinal fluid loses its protective property in certain concentrations or acquires properties that enhance the precipitation of colloids. The M. r. was proposed in 1915 by Emanuel. According to Emanuel's prescription, the basic solution of mastic is prepared, for which 10.0 of mastic (see) is dissolved in 100 cm³ of absolute alcohol, shaken and filtered (according to Jacobsthal-Kafka, the solution is allowed to stand for 24-48 hours in the cold before filtering). From this basic solution, the colloidal solution of mastic is prepared ex tempore for the reaction: 1 cm³ of the basic solution is drawn into a pipette and 9 cm³ of absolute alcohol, and this mixture is poured drop by drop over a period of one minute into 40 cm³ of Aq. destill. with constant shaking of the latter. A milky-white emulsion is obtained, which is allowed to stand at room temperature for 30-60 minutes (ripening of the solution). Cerebrospinal fluid is used for the reaction in dilutions from 1:2 to 1:7, with the fluid being diluted with a 1.25% solution of NaCl. In Emanuel's prescription, the M. r. did not become widespread and underwent a number of modifications, mainly concerning the electrolyte medium in which the cerebrospinal fluid is diluted and the quantity of dilutions of the cerebrospinal fluid. Of the numerous modifications, the one most widely used is the modification proposed by Jacobsthal and Kafka. The mastic emulsion is also prepared according to Emanuel's prescription. For dilution of the cerebrospinal fluid, a previously titrated solution of NaCl is used. For titration, solutions of NaCl in concentrations of 0.1-0.2-0.3... 1.5% are taken, and to 1 cm³ of each dilution, 1 cm³ of mastic emulsion is added. For the reaction, that dilution of NaCl is used which first gave precipitation of mastic. The reaction is set up in 12 test tubes (the 12th serves as control) according to the scheme shown in Fig. 1. After setting up the experiment, the test tubes are carefully shaken, plugged with cotton, and left at room temperature. The result is noted after 24 hours. In positive cases, the formation of a flaky precipitate and a change in the turbidity of the mastic emulsion are obtained. The degree of precipitate and clarification of the emulsion in different test tubes is represented graphically in the form of curves. The following types of curves have been established: normal curve, curve with syphilitic tooth (Lueszacke), curve of lues cerebri, paralytic and meningitic curves (Figs. 2 and 3). A further modification, also widely distributed, belongs to Kafka. In his modification, the cerebrospinal fluid is examined undiluted and in dilutions of 3:4-1:2-1:4, etc., up to 1:4,000. For dilution of the cerebrospinal fluid, a solution of blood plasma salts (Normosal) is used, if the titer of NaCl for this mastic emulsion ranges from 0.6-0.8%. If, however, the titer of NaCl is higher or lower than these figures, the first concentration of NaCl that caused precipitation of mastic is taken, adding to it a 0.5% solution of Natrii carbonici in the amount of 1 cm³ per 99 cm³ of NaCl solution. This modification is known under the name of normomastic reaction.

For a more precise reading of the reaction results, Kafka proposed staining the mastic emulsion with a saturated alcoholic solution of Sudan III (1 cm³ of the basic solution of mastic and 0.5 cm³ of Sudan III + 8.5 cm³ of absolute alcohol are drawn into a pipette and poured, as indicated above, into 40 cm³ of Aq. destill.). Staining is applicable in both the Jacobsthal-Kafka modification and the normomastic reaction. Of the little-used modifications of the M. r., one can mention the modification of Ketting: stabilization of the electrolyte medium, which, according to the author, is achieved by adding alkali to the NaCl solution (to 100 cm³ of a 0.7% solution of NaCl, 1 cm³ of a 0.5% solution of Natr. carbon. is added); the modification of Goebel: a NaCl solution is used in a constant concentration of 0.8%, and the cerebrospinal fluid is examined in dilutions from 1:2 to 1:64 (6 test tubes); the modification of Emanuel-Rosenfeld, in which a NaCl solution with a constant degree of alkalinity very close to the alkalinity of lumbar fluid (pH=7.4) (Lumbo-test) is used for dilution of the cerebrospinal fluid; for this purpose, a phosphate buffer mixture with a precisely established concentration of hydrogen ions (pH=7.5) is added to a 1.25% solution of NaCl. All the numerous modifications of the M. r. aim to achieve constancy in the behavior of the mastic emulsion with respect to the electrolyte medium in which the reaction proceeds, in order to reveal in a purer form the influence of the cerebrospinal fluid on the colloidal solution of mastic. However, due to the instability of the mastic emulsion, which easily changes its properties from standing, shaking, method of preparation, etc., all attempts in this direction have not yet given satisfactory results. This circumstance to a large extent reduces the practical value of the M. r. Diagnostic significance of the M. r.: a positive M. r. is obtained only with organic lesions of the central nervous system (according to some authors also of the peripheral nervous system). The meningitic curve is more frequently obtained with lesions of the meninges regardless of the etiology of the disease. With regard to the other curves, it can be noted that there is a tendency for them to appear more frequently in those diseases whose names these curves bear. A shift of the curve to the left along the grid is more frequently observed with parenchymal lesions (progressive paralysis, tabes dorsalis, multiple sclerosis, brain tumors, etc.), while a shift of the curve to the right (meningitic curve) is characteristic of inflammatory processes in the meninges. The degree of these lesions of the nervous system is determined by the depth of the curves. For the etiological diagnosis of nervous diseases, the M. r., like colloidal reactions in general, is little suitable, but it acquires important significance in the overall assessment of changes in the cerebrospinal fluid and in known syphilis in patients. In the latter case, it plays a role in the prevention of syphilis of the nervous system, registering the slightest lesions of the nervous system by infection, not yet detectable by other examinations of the cerebrospinal fluid, in the area of prognosis in syphilis of the nervous system (persistence of the reaction is a less favorable prognosis) and as a control of treatment. According to clinical evaluation and ease of performance, the M. r. is somewhat inferior to the Lange reaction with colloidal gold.