The production of EAE in the fully susceptible BSVS mouse genotype has been found to be dependent on the ratio of proteolipid antigen and adjuvant mycobacterial concentration as used in the emulsion, of the Freund type. Disturbance of this ratio, by manipulation of either component, by diminution or increase, results in a decrease in the frequency by which EAE is produced. Simultaneous reduction of antigen and mycobacteria, so that the ratio remains unchanged, retains the full EAE-producing power of the emulsion. The limit of this has not been ascertained. Emulsifying agents have been found to restrict further the permissible limits of the antigen-mycobacterial ratio for full EAE production. Such effects of the emulsifier have been found to vary with the qualitative nature of the emulsifier. Aquaphor has been found to be less restrictive than falba. These phenomena, systematically analyzed here for the mouse, may have an application for other antigen-adjuvant systems and for other hosts.

MURINE ACUTE DISSEMINATED ENCEPHALOMYELITIS 263 0.26. Metachromasia was tested with toluidine blue. None of the supernatant fluids from synovial tissue cultures and control developed metachromasia. Heparin (as little as 5 pg per ml) and other sulfonated mucopolysaccharides showed strong metachromasia with toluidine blue.Electrophoretic Studies. To further establish the nature of the mucopolysaccharides found in the supernatants, electrophoretic patterns were obtained with a Perkin-Elmer Tiselius apparatus.Supernates with negative acetic acid precipitation tests gave protein patterns with peaks characteristic of the globulins and albumin. The latter gave the highest and fastest moving peak (Fig. la). Supernates which gave a positive precipitation test showed a new peak in front of the albumin (Fig. lb). The mobility of this component was in the range of hyaluronic acid verified by the addition of purified hyaluronic acid to a negative supernatant fluid (Fig. lc). None of the supernates exhibited a peak with a faster mobility than that for hyaluronic acid. The sulfonated mucopolysaccharides such as chondroitin sulfuric acid or heparin have a faster mobility than the hyaluronic acid. This is seen in the electrophoretic pattern obtained when heparin is added to a tissue culture supernate positive for hyaluronic acid (Fig. Id).1. Growth of human and animal synovial membrane in tissue cultures showed characteristic differences from control cultures of periarticular tissues. 2. Presence of hyaluronic acid in about two-thirds of supernates of tissue cultures. from synovium was demonstrated by precipitation reactions with acetic acid, enzymatic reactions, viscosity determination, tests for metachromasia and electrophoretic patterns. 3. Quantitative determinations by a turbidimetric method yielded a concentration of hyaiuronic acid from 4 to 15 mg %. 4. Tests were negative for sulfonated mucopolysaccharides such as chondroitin sulfuric acid or heparin. 5. Control cultures of periarticular connective tissue were negative for hyaluronic acid and sulfonated mucopolysaccharides.

Salmonellosis in the mouse is an infectious disease which, both as an unwanted natural event in mouse colonies and as an experimental "model" infection in the laboratory, has received considerable investigative attention.

No abstract

The susceptibility of homozygous BSVS mice to acute disseminated encephalomyelitis (ADE) has been found to be nutritionally dependent. On a laboratory stock regimen of commercial fox chow pellets, whole wheat bread, and milk this genotype is 100 per cent susceptible to the disease. On a "synthetic" diet, containing a minimal list of vitamins adequate for growth and maintenance, susceptibility was found to be reduced to 15 per cent. Supplementation of the "synthetic" diet with biotin, folic acid, and vitamin B12 restored susceptibility to a frequency of 70 per cent. Increasing the supplements tenfold had no further effect in restoring susceptibility frequencies to the 100 per cent level. In the restoration of susceptibility, folic acid and vitamin B12 were equally effective as single supplements and equivalent to the triple vitamin supplement. The effect of single biotin supplementation was less. An outbreak of fatal pasteurellosis among BSVS mice latently infected with Pasteurella and used in an ADE susceptibility test has been described. The fatal pasteurellosis has been ascribed to a constellation of determinants including (a) diet, (b) sex, (c) inoculation events, and (d) latent infection with Pasteurella. With males the susceptible sex it was possible to avert the fatal pasteurellosis and continue the nutritional experiments by using females exclusively.