Enteric infection with an obligate intracellular parasite, Encephalitozoon cuniculi, in an experimental model.

Rabbits were intrarectally infected with 3 doses (5 x 10(3), 5 x 10(5), and 5 x 10(7] of an obligate intracellular parasite, Encephalitozoon cuniculi, with or without prior colonic lavages. Although chronic administration of enemas seems to interfere to some degree with the intestinal translocation of the parasite, systemic infection was observed in both manipulated and nonmanipulated animals. The animals responded with antibodies of immunoglobulin A (IgA) and IgG isotypes, reflecting the route of infection. They also produced significant amounts of circulating immune complexes composed of IgA and IgG antibodies and E. cuniculi antigens. Lesions compatible with encephalitozoonosis were seen in the liver, kidney, lung, and brain. In all instances, nonmanipulated animals had more severe lesions than manipulated rabbits given the same dose of parasites. Levels of serum antibodies, circulating immune complexes, and histopathologic changes were associated with the infection dose. The presented data suggest that human microsporidiosis may also be transmitted via the rectal route. It is, therefore, of clinical relevance in view of several reports of microsporidian infections in patients with acquired immunodeficiency.

The effect of dietary fish oil supplementation on psoriasis. Improvement in a patient with pustular psoriasis.

An open study testing the effects of fish oil supplementation on psoriasis in 26 patients is described. None of the patients with plaque-type psoriasis vulgaris showed clinically significant improvement; however, a patient with generalized pustular psoriasis showed marked improvement with the fish oil supplementation. In this patient, scale leukotriene B4 levels were determined and shown to be significantly decreased after completion of the study, but the leukotriene B4 levels did not correlate with her clinical course. The results of our study are contrasted with those of a recent study that did show beneficial effects of fish oil supplementation on plaque-type psoriasis.

Evaluation of Sch 29482 in experimental syphilis and comparison with penicillin G benzathine in disseminated disease and localized infection.

The present study was designed to assess the in vivo activity of Sch 29482, a new penem antibiotic, against disseminated and localized Treponema pallidum infections in rabbits. Animals were inoculated either intravenously or intradermally. Randomized groups then received 25 or 50 mg of Sch 29482 per kilogram of body weight twice a day for 7 days, two weekly injections of 200,000 U of penicillin G benzathine for comparative purposes, or no antibiotic therapy. In both infection models, striking differences were noted between the untreated control rabbits and rabbits receiving penicillin G benzathine or high-dose Sch 29482. Intravenously infected rabbits did not develop disseminated lesions or orchitis, and chancres produced by intradermal infection regressed and healed rapidly after both treatment regimens. Infectivity studies also suggested that high-dose Sch 29482 and penicillin G benzathine were effective since the testes and lymph nodes of treated animals were free of infectious organisms. Treatment of animals with the lower dose of Sch 29482 represented borderline or suboptimal therapy, with a failure rate of one in four for each infection model.