Experimental canine mucocutaneous leishmaniasis (Leishmania braziliensis braziliensis)

Four mongrel dogs were intradermically inoculated with 3 x 10**6 Leishmania braziliensis braziliensis promastigotes. Three out of the four animals developed cutaneous lesions respectively 4, 7, and 8 months after. The fourth dog did not develop lesion at the inoculation site, but a mucosal ulcer was seen 16 months after the inoculum. Clinical, histopathological, and serological findings were similar to what is found in natural canine infection as well as in the human disease. These results suggest that dogs may be an useful model for L. b. braziliensis infection.

Epidemiologia de la leishmaniasis tegumentaria en merida, Venezuela. I. Diversidade y dispersion de especies flebotominas en tres pisos altitudinales y su possible rôle en la transmission de enfermedad

Como parte de un estudio epidemiológico sobre leishmaniasis en el Estado Mérida, Venezuela, se presenta la diversidad y dispersión de las especies flebotominas identificadas en 15 localidades ubicadas en 3 pisos altitudinales entre los 175 y los 1.960 m.s.n.m. De 7.126 espécimes capturados (5.132 hombres y 1.994 femenino) se registran 24 especies de Lutzomyia, reconociéndose 10 de las llmadas antropofílicas. Se detalla la distribución de las especies en cada piso altitudinal y en el domicilio humano, el peridomicilio y el ambiente silvestre. Se discute el posible papel que juegan las diferentes especies en la transmisión de la leishmaniasis tegumentaria en cada piso altitudinal en particular y en la región andino-venezolana, en general.

Epidemiologia de la leishmaniasis tegumentar en Mérida, Venezuela - II. Redescripcion de Lutzomya yencanensis (Ortiz, 1965) (Diptera: Psychodidae)

Se redescribe la hembra y el macho de Lutzomya Yencanensis OOrtiz, 1965) utilizando 11 topotipos. Se presentan las medidas e ilustraciones de las estructuras morfológicas. Se hace un análiseis comparativo con las especies afines y se registra la presencia de L. yencanensis en la región Andino-Venezolana.

B cell dependent T lymphocyte responses in leishmaniasis

The activation of B cell dependent T cells during Leishmania infection cannot be considered a trivial event, because their removal profoundly alters the course and outcome of infection within genetically susceptible and resistant mouse strains. The demonstration that idiotype recognizing T cells also appear within human populations sensitized to leishmanial antigens as a result of asymptomatic or subclinical infections supports a role for these cells in immunity. These cells are not demonstrable in patients with active visceral disease, so that their role in promoting specific unresponsiveness has not been extended to humans. Whether B cell dependent, idiotype specific T cells represent a functionally distinct T lymphocyte subset with unique regulatory activities remains to be determined.