Paola Barato | PubMed Health

PubMed2005

Cutaneous tuberculosis diagnosis in an inhospitable Amazonian region by means of telemedicine and molecular biology.

We report on a 13-year-old boy who displayed a chronic granulomatous inflammatory reaction of 5 years duration. The lesion was resistant to different antibiotic schemes; his routine laboratory tests and chest radiographs were normal. Teledermatologic consultation and histopathologic study of skin biopsy suggested scrofulodermal tuberculosis. Polymerase chain reaction amplification of DNA extracted from lymph node biopsy was taken as starting material for dot-blot hybridization using Mtp-40 and IS 6110 as probes for detecting either Mycobacterium tuberculosis or any mycobacteria belonging to the M tuberculosis complex, respectively. Positive results in both hybridizations were further confirmed by culturing in BACTEC MGIT 960 system. The lesion greatly diminished following isoniazid, rifampin, and ethambutol treatment. Telemedicine allowed a cutaneous tuberculosis diagnosis to be made of a patient living in a remote town located in the Amazon jungle by using molecular biology techniques.

Adolescent↗

PubMed2004

Identifying and structurally characterizing CD1b in Aotus nancymaae owl monkeys.

This study reports the molecular characterization and tissue expression of the non-human Aotus nancymaae primate CD1b isoform in the search for an experimental animal model to be used in evaluating the role of non-peptide antigen-presentation molecules in the immune response to infectious agents. CD1b expression on the surface of A. nancymaae peripheral blood monocyte-derived dendritic cells, shown by flow cytometry, was made possible by using human CD1b isoform antibodies. Studying the expression of CD1b-encoded transcripts revealed this molecule's broad distribution in several tissues. The A. nancymaae CD1b transcript-encoded amino-acid sequence showed 95.5% identity with the human sequence. Such high sequence homology was reflected in the identical structural conservation of how pockets A', C' and F' and tunnel T' conforming the antigen's binding site are organized, the similar arrangement of those amino-acids interacting with the T-cell receptor (TCR) during antigen presentation, and the conservation of YQNI-motif sequence in the cytoplasmatic tail (responsible for the molecule's intracellular trafficking in humans). Comparing the structure of human CD1a and CD1b and mouse CD1d proteins with CD1b structure in A. nancymaae obtained by minimization revealed that changes in the latter molecule's alpha1 and alpha2 domains imposed a narrowing of the antigen-binding groove in A. nancymaae CD1b. The high structural similarity between A. nancymaae CD1b and that from humans presented in this study leads to A. nancymaae being proposed as a suitable experimental animal model for analyzing CD1b in vivo, mainly in bacterial and parasite infections such as tuberculosis and malaria, respectively.

Amino Acid Sequence↗