How reliable are models for malaria vaccine development? Lessons from irradiated sporozoite immunizations.

Models occupy a key position in the development of anti-parasitic vaccines, yet their relevance has been seldom addressed. It is customary to admit that malaria vaccine development requires easy-to-handle, laboratory models. Animal models involving predominantly inbred rodents and primates as parasite hosts are currently the basic tools for the study of host-parasite interactions. Literature however indicates that the induction of host protection is more difficult in natural host-parasite pairs than in experimental models of parasite infection. Moreover different models delineate a wide range of host-pathogen relationship profiles providing a mosaic of contradictory informations, yet there is little incentive to delineate their relevance or to exploit recent advances to develop improved model systems. In this context the analysis of natural host-parasite interactions between Plasmodium berghei and its mammalian host and reservoir, the tree rat Grammomys surdaster could ge of relevance in the study of host-parasite interactions.

An unusual case of ectopic tungiasis with pseudoepitheliomatous hyperplasia

Tungiasis is caused by the penetration of the female sand flea Tunga penetrans into the epidermis, and subsequent hypertrophy of the parasite. In most cases lesions are confined to the feet. During a cross-sectional study, an unusual case of ectopic tungiasis in the inguinal area was detected. Histological examination of tissue samples showed a remarkable pseudoepitheliomatous aspect of the epidermis. Clinical features and differential diagnoses are discussed.

Modelo experimental de la transmisión congénita de la enfermedad de Chagas en ratones NMRI (fase aguda) / Experimental model of congenital Chagas' disease transmision in NMRI mice (acute phase)

Es estudiada la transmisión congénita del T. cruzi en ratones de la cepa NMRI. La infección aguda fue producida por inoculación de formas tripomastigotes de T. cruzi de la cepa Tulahuen, en dos diferentes fase de la gestación (inicial) 4to. día y tardía 12avo. día). Los ratones fueron sacrificados en la fase aguda de la infección, los tejidos animales, fetos y placentas fueron estudiados histopatológicamente. Se observó infección placentaria en vellos coriales, membranas con alteraciones de leves a severas de placentas definidas por la necrosis y el depósito de substancia fibrinoide. La transmisión transplacentaria del T. Cruzi en las crias fue demostrado por seguimiento parasitológico (método directo). Estas observaciones son un nuevo aporte a lo que, ya se conoce sobre el mecanismo de transmisión congénita de la enfermedad de Chagas a nivel experimental

Schistosomal glomerular disease (a review).

A glomerulopatia esquistossomotica e um exemplo de doenca causada por complexos imunes. Ela se manifesta em 12 a 15% dos portadores de forma hepato-eplenica da esquistossomose. A hipertensao porta, com circulacao colateral, facilita a ultrapassagem do filtro hepatico e os antigenos esquistossomoticos podem se acoplar aos anticorpos na circulacao e vir a se depositar nos glomerulos. O tipo histologico mais frequente e a glomerulonefrite cronica membrano-proliferativa, geralmente com sindrome nefrotica. A doenca e passivel de reproducao experimental e os antigenos esquistossomoticos, os anticorpos e fracoes do complemento podem ser demonstrados nas lesoes glomerulares. O tratamento especifico da esquistossomose nao mostrou ate o momento a capacidade de alterar o curso da nefropatia