A lipolytic enzyme in reactive histiocytes of guinea pigs with experimental encephalomyelitis

A lipolytic enzyme has been demonstrated by means of a cytochemical technique and by direct chemical assay in granulomatous tissues of guinea pigs with encephalomyelitis and demyelinization resulting from the injection of an emulsion comprised of brain tissue and adjuvants, including Mycobacterium butyricum. Combined histologic and cytochemical studies showed that the lipolytic enzyme was present in the cytoplasm of a large proportion of the reactive histiocytes in the granulomatous tissue around the site of injection in the diseased animals, and that the enzyme-containing histiocytes were even more numerous in the inflamed regional lymph nodes. In control experiments, when emulsions lacking either brain tissue or M. butyricum were injected in previously normal guinea pigs, the experimental condition did not develop; under these circumstances the lipolytic enzyme was found in only a small proportion of the cells of the granulomatous tissue around the injection sites, and it was almost negligible in the regional lymph nodes of these animals. It was absent from the cells of the lymph nodes of normal animals, and from the cells of talcum and aluminum hydroxide granulomas produced experimentally in guinea pigs. The lipolytic enzyme may be a factor in the pathogenesis of the experimental encephalomyelitis and demyelinization.

Studies on acute disseminated encephalomyelitis produced experimentally in rhesus monkeys

The white cell count, total protein, gamma globulin, and percentage of gamma globulin in the cerebrospinal fluid of monkeys with acute disseminated encephalomyelitis produced by the injection of brain emulsions with adjuvants have been studied. The acute phase of the disease is characterized by a rise in the white cell count, total protein, and gamma globulin in the cerebrospinal fluid. In some instances the percentage of gamma globulin, to the total protein may be normal while in others it is elevated. As the acute process subsides, the total protein declines and animals frequently show an increase in the percentage of gamma globulin to total protein. The relation of the cerebrospinal fluid findings in acute disseminated encephalomyelitis in the rhesus monkey to those in human multiple sclerosis is discussed.

Transfer of allergic encephalomyelitis in rats by means of lymph node cells

Transfer of allergic encephalomyelitis has been accomplished by injection of lymph node cells, obtained from donor rats sensitized to spinal cord, into recipient rats pretreated neonatally with normal rat spleen cells. Transfer of the disease may be achieved most frequently when the recipients are pretreated with spleen cells of the prospective lymph node cell donors. These transfers are attributed to the use of recipients which have acquired immunological tolerance to donor lymph node cells, as a result of the spleen cell pretreatment, and in which, therefore, the donor cells can survive and function longer after transfer.