Cerebral tumor-like American trypanosomiasis in acquired immunodeficiency syndrome.

Cerebral tumor-like American trypanosomiasis (CTLAT) is an uncommon complication of Chagas' disease, observed only in immunosuppressed patients. We assessed 10 human immunodeficiency virus-positive patients with Chagas' disease who presented with CTLAT. All patients had neurological involvement and 6 developed intracranial hypertension. Neuroimaging studies showed supratentorial lesions in 9 patients, being single in 8. One case had infratentorial and supratentorial lesions. Low CD4+ cell counts were observed in all the cases and in 6 of them CTLAT was the first manifestation of acquired immunodeficiency syndrome. Serological tests for Chagas' disease were positive in 6 of 8 patients. Trypanosoma cruzi was identified in all brain specimens and in three cerebrospinal fluid samples. CTLAT should be considered in the differential diagnosis of intracranial mass lesions in human immunodeficiency virus-positive patients and should be added to the list of acquired immunodeficiency syndrome-defining illnesses.

Chagasic granulomatous encephalitis in immunosuppressed patients. Computed tomography and magnetic resonance imaging findings.

American trypanosomiasis (Chagas' disease), a zoonosis caused by Trypanosoma cruzi with a high incidence in Latin America, may induce an uncommon form of localized encephalitis termed "chagoma", found in few immunocompromised patients. The computed tomography (CT) and magnetic resonance imaging (MRI) findings of brain chagoma are reported for 3 males (ages 32, 32 and 9 yr), the first 2 infected with human immunodeficiency virus (HIV) and the third with acute lymphoblastic leukemia. Diagnosis was confirmed by biopsy. CT disclosed a single, supratentorial, nodular-shaped lesion that substantially enhanced with contrast material, localized in parietal or frontal lobes. T1-weighted MRI showed hypointense lesions that enhanced with gadolinium-diethylenetriaminepentaacetic acid, corresponding to extensive hyperintense areas on T2-weighted images, producing mass effect. The imaging pattern of brain chagoma presented here is similar to that of cerebral toxoplasmosis and should be considered in the differential diagnosis of an intracerebral mass lesion in immunocompromised patients.

Different peptides from hemorrhagic septicemia rhabdoviral proteins stimulate leucocyte proliferation with individual fish variation.

Trout leucocytes from most of the survivors of viral hemorrhagic septicemia virus (VHSV) infections were capable of in vitro proliferation (T-like response) when cultured in the presence of short synthetic peptides designed from the G and the N cDNA-derived protein sequences of VHSV, a virus with substantial economic impact in trout farms. In contrast, no significant proliferative responses were obtained for the above-mentioned peptides from leucocytes obtained from either noninfected or genetically VHSV-resistant trout. However, since the anamnestic recognition of particular peptides (epitopes) of the G and the N protein by trout leucocytes varies largely within the outbred trout population, larger VHSV protein fragments were also tested. The finding that recombinant G and N fragments carrying multiple epitopes are recognized by the majority of the individual trout surviving VHSV infections and with higher stimulation indexes suggests that the recombinant viral proteins could be used as vaccines given the outbred nature of the fish.