[Specific humoral response in Balb/c mice inoculated with a genome library of expression of Trypanosoma cruzi]. / Respuesta humoral específica en ratones Balb/c inoculados con una librería genómica de expresión de Trypanosoma cruzi.

A genomic expression library of Trypanosoma cruzi (T. cruzi) was made using plasmid pcDNA3 as a vector, with which male mice from the Balb/c isogenic line were intramuscullary inoculated. It was used a positive control group that was administered soluble antigens of T. cruzi. Other 2 groups received genomic and plasmid DNA, respectively. One group was not immunized. Weekly blood samples were obtained from all the animals until the fourth week and 2 weeks after reimmunization to study the response of specific antibodies against the microorganism antigens by an indirect immunoenzymatic assay (ELISA). It was observed a significant increase of specific antibodies in the animals reimmunized with 50 micrograms of the library, as well as in the group immunized with soluble antigens of T. cruzi.

[Validation in Havana City, Cuba of ENZYMEBA, an immunoassay for detecting Entamoeba histolytica in feces]. / Validación en ciudad de La Habana, Cuba, de ENZYMEBA, inmunoensayo para la detección de Entamoeba histolytica en heces.

Parasitologists from different medical institutions in Havana City carried out the external validation of ENZYMEBA, a diagnostic procedure of intestinal amebiasis developed at the "Pedro Kourí" Institute of Tropical Medicine. To this end, serial faeces specimens from 212 individuals were collected and observed on the microscope (reference test). The ENZYMEBA immunoassay (validation test) was also made. On comparing ENZYMEBA with the microscopic examination, satisfactory indexes of sensitivity and specificity were found. No cross-reactions were detected in faeces specimens, where found other parasites were present, too. Taking into account that only one faeces specimen per patient is enough for the diagnosis of intestinal amebiasis with ENZYMEBA, this procedure may be useful in studies of therapeutical efficacy and prevalence.

[Cysteine-dependent protease in Trypanosoma cruzi useful for the diagnosis of Chagas disease]. / Proteasa dependiente de cisteína en Trypanosoma cruzi útil en el diagnóstico de la enfermedad de Chagas.

An immunoenzymatic system on solid phase for the detection of IgG antibodies in serum from chronic Chagasic patients was standardized. A protease from Trypanosoma cruzi (GP57/51KDa) was used as an antigen. The sensitivity, specificity and predictive values of the procedure were calculated taking into account the results obtained from conventional serology (CS), indirect immunofluorescence (IIF), indirect hemagglutination (IHA) and complement-mediated lysis test (CML) for the detection of anti-Trypanosoma cruzi antibodies in serum. Except one, the positive samples obtained by those techniques were also positive by our method. These results show that GP 57/51 is useful in the serodiagnosis of Chagas disease.