Evaluation of different immunization protocols with P. brasiliensis antigens in guinea pigs

The objective of the present study was to develop an efficient and reproducible protocol of immunization of guinea pigs with P. brasiliensis antigens as an animal model for future studies of protective immunity mechanisms. We tested three different antigens (particulate, soluble and combined) and six protocols in the presence and absence of Freund's complete adjuvant and with different numbers of immunizing doses and variable length of time between the last immunizing dose and challenge. The efficacy of the immunizing protocol was evaluated by measuring the humoral and cellular anti-P. brasiliensis immune response of the animals, using immunodiffusion, skin test and macrophage migration inhibition test. It was observed that: 1. Three immunizing doses of the antigens induced a more marked response than two doses; 2. The highest immune response was obtained with the use of Freund's complete adjuvant; 3. Animals challenged a long time (week 6) after the last immunizing dose showed good anti-P. brasiliensis immune response; 4. The particulate antigen induced the lowest immune response. The soluble and the combined antigens were equally efficient in raising good humoral and cellular anti-P. brasiliensis immune response.

Neurocysticercosis: treatment with albendazole and dextrochloropheniramine

We evaluated the use of albendazole in combination with dextrochloropheniramine for the treatment of neurocysticercosis. Forty patients were treated from September 1984 to December 1987; each was diagnosed on the basis of clinical, epidemiological, cerebrospinal fluid and tomographic data. Patients were divided into 3 groups according to the albendazole treatment schedule. Group I received 10-15 mg/kg albendazole daily; group II received 15-25 mg/kg/d; group III received 15-30 mg/kg/d. Each patient also received simultaneously 18 mg/d of dextrochloropheniramine. Clinical improvement was observed in 4 patients in group I (50.0%), 10 patients in group II (83.3%) and 18 patients in group III (94.7%). Three patients in group II, and one in group III, died. Group III patients showed a significant improvement in quality of life compared to the other 2 groups. Side effects were insignificant in all groups. The combination of albendazole and dextrochloropheniramine seems to be a promising treatment for neurocysticercosis, especially at the doses used for group III, i.e. 15 mg/kg/d of albendazole for 21 d followed by 20-30 mg/kg/d for 30 d after a one-week interval, in combination with 18 mg/d of dextrochloropheniramine.

Protective effect of prior immunization on ocular paracoccidioidomycosis in guinea pigs

The present study reproduced the experimental model of ocular paracoccidioidomycosis in guinea pigs, by the intracardiac inoculation of yeast-forms of P. brasiliensis. Ocular involvement was observed in 80% of the infected animals. The uvea, ciliary body, choroid, iris, lids and the conjunctiva were the structures most commonly affected. To protect the animals against the infection, an immunization protocol was standardized utilizing a P. brasiliensis soluble antigen in Freund's complete adjuvant, administered weekly, during 3 weeks, by the subcutaneous route. Two weeks later, previously immunized guinea pigs were challenged by the intracardiac route with yeast-forms of P. brasiliensis (vaccinated group). When compared with a control group (infection in the absence of prior immunization), the vaccinated animals developed higher levels of anti-P. brasiliensis cellular and humoral immune response and a three times lower frequency of ocular involvement (85.7% vs 28.5%). In addition, the ocular lesions were significantly more localized and contained less fungal cells. The data demonstrated that the subcutaneous immunization was effective in decreasing the frequency and extent of ocular lesions, as well as in blocking fungal multiplication.

Paracoccidioidomycosis: study of six cases with ocular involvement

We present 6 patients with ocular involvement due to paracoccidioidomycosis. All cases were confirmed by the finding of Paracoccidioides brasiliensis in histopathological or direct mycologic examination of material from the lesion in the eyelid or conjunctiva. In two cases the bulbar conjunctiva was also involved, in another the cornea, and still another patient developed endophthalmitis. The presence of this mutilating disease which may lead to blindness should be suspected when chronic blepharitis or palpebral ulcerated papular lesions are detected in patients from endemic areas of paracoccidioidomycosis. This etiology should also be suspected in patients with anterior and posterior uveitis after discarding the most frequent causes of this condition.