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Biomedical subjects

N J Alvarenga

Publications and source records attributed to N J Alvarenga.

At least 19 recordsLinked to original sources
PubMed1979

Dipetalogaster maximus (Hemiptera, Triatominae) for xenodiagnosis of patients with serologically detectable Trypanosoma cruzi infection.

In patients serologically positive for Trypanosoma cruzi infection the three bug species/instar combinations used in xenodiagnosis showed third-instar Dipetalogaster maximus to be more efficient in detecting circulating trypanosomes than the first instar of the same species which, in turn, is more sensitive than third-instar Triatoma infestans. The sensitivity of the pool technique of faecal examination compared with individual dissection was investigated. Four pool examinations (the product of 20 bugs) were equivalent to 10 individual bug dissections. Because of the ease of providing large numbers of bugs for mass xenodiagnosis, first-instar D. maximus has replaced third-instar T. infestans in our routine work. The value of third-instar D. maximus as a xenodiagnostic agent needs further investigation.

Chagas Disease↗
PubMed1978

Development of Trypanosoma cruzi in the vector in the absence of blood.

First stage nymphs of Triatoma infestans and Dipetalogaster maximus which had never fed after egg hatching, were allowed to ingest by artificial feeding a blood-free suspension of Trypanosoma cruzi trypomastigotes collected from experimentally infected mice. A high percentage of the vectors acquired a normal infection and produced infective stages. The parasite's development in the vector did not require blood but may have needed the presence of unknown factors secreted and/or excreted in the insect's digestive tract.

Insect Vectors↗
PubMedDate not supplied

[Xenodiagnosis and criteria to assess the level of parasitemia in chronic chagasic patients].

Xenodiagnosis sensibility and its relation to Chagas' disease chronic phase parasitemia was verified in 104 patients. The nymphs of the triatomine species, simultaneously utilized in the xenodiagnosis of these patients, divided into two groups, were examined in different ways. The positivity rates achieved in the two groups (40.0% and 42.4%) and the individual positivity rates suggest a reavaliation in what is called "quantification of the chronic chagasic patient parasitemia", considering the methodology used in the xenodiagnosis examinations.

Animals↗
PubMedDate not supplied

Human immune response to triatomine embryo extract.

Dipetalogaster maximus embryo extracts were used to stimulate peripheral blood mononuclear cells (PBMC) and in ELISA with sera either from Trypanosoma cruzi infected or non-infected individuals. The results showed that there was significant proliferative response and high antibody, titers in sera of chagasic patients.

Animals↗
PubMedDate not supplied

A simplified method for sample collection and DNA isolation for polymerase chain reaction detection of Trypanosoma rangeli and Trypanosoma cruzi in triatomine vectors.

Due to the overlapping distribution of Trypanosoma rangeli and T. cruzi in Central and South America, sharing several reservoirs and triatomine vectors, we herein describe a simple method to collect triatomine feces and hemolymph in filter paper for further detection and specific characterization of these two trypanosomes. Experimentally infected triatomines feces and hemolymph were collected in filter paper and specific detection of T. rangeli or T. cruzi DNA by polymerase chain reaction was achieved. This simple DNA collection method allows sample collection in the field and further specific trypanosome detection and characterization in the laboratory.

Animals↗