PubMed Health⌕ Search

Biomedical subjects

A B Sánchez

Publications and source records attributed to A B Sánchez.

4 recordsLinked to original sources
PubMed2006

Food-dependent exercise-induced anaphylaxis to pistachio.

We report the case of a 16-year-old male who, 30 minutes after beginning to play football with previous ingestion of pistachio nuts, experienced an anaphylactic reaction. Prick-by-prick test with roasted pistachios was negative. Specific IgE antibodies to pistachio, cashew nuts and mango were negative. An open oral challenge test with pistachio in resting conditions was negative. Treadmill ergonometric stress in a fasting state and 60 minutes after a meal without pistachio gave negative results. A specific food exercise challenge 60 minutes after ingestion of 50 g pistachio nuts was positive, showing mild diffuse erythema and small wheals in face and thorax. To the best of our knowledge, this is the first described case of specific food dependent exercise-induced anaphylaxis to pistachio. Negative allergologic tests is an unusual condition, since most cases appear to be IgE-mediated. In this case, a positive specific food exercise challenge test provided a definite diagnosis.

Adolescent↗
PubMed2002

Visna/maedi virus Env protein expressed by a vaccinia virus recombinant induces cell-to-cell fusion in cells of different origins in the apparent absence of Env cleavage: role of glycosylation and of proteoglycans.

The in vivo productive infection by the ovine Visna/maedi lentivirus (VISNA) is restricted to cells of the monocyte/macrophage lineage. The basis for this restriction is not understood. Although the VISNA envelope (Env) glycoprotein is the main target for virus neutralization, studies on the role of this protein in virus infection are limited. A vaccinia virus recombinant (VV- env-MV) containing the entire VISNA env sequence was generated and shown to produce in infected cells a protein of about 165 kDa (referred to as gp150). During VV- env-MV infection, expression of env caused extensive cell-to-cell fusion in cell lines of different origins. Pulse-chase and Western blot analyses revealed that gp150 is not cleaved in VV- env-MV infected cells. The glycoprotein gp150 formed oligomers held by disulfide bonding. Cell-to-cell fusion was prevented in the presence of the inhibitor of glycosilation, tunicamycin, but it was markedly enhanced by an inhibitor of proteoglycan synthesis, beta-D-xyloside. These findings showed that the receptor for VISNA Env is widely distributed within cells, that fusion-from-within of cells can occur in the apparent absence of proteolytic cleavage of gp150, and that fusion require a glycosylated Env but not the addition of proteoglycan chains at the cell surface. This recombinant virus could have utility as a potential vaccine against VISNA.

3T3 Cells↗
PubMed1999

Proteolytic processing in infectious bursal disease virus: identification of the polyprotein cleavage sites by site-directed mutagenesis.

The infectious bursal disease virus (IBDV), a member of the Birnaviridae family, is the causative agent of an immune depressive disease that affects domesticated and wild avian species. The expression strategy of IBDV includes the synthesis of a 110-kDa polyprotein containing the capsid precursor polypeptides. The polyprotein is autocatalitically processed rendering three polypeptides: NH2-VPX-VP4-VP3-COOH. We have carried out a systematic analysis, using a series of plasmids encoding polyproteins containing either deletions or single amino acid substitutions, to identify the processing sites. The results obtained showed the existence of two sites, 511LAA513 and 754MAA756, that are essential for the processing of the VPX-VP4 and VP4-VP3 precursors, respectively. These sequences are highly conserved among IBDV strains form serotypes 1 and 2. A secondary VPX-VP4 processing site was detected in a 19-amino acid stretch located upstream of the 511LAA513 site. Analyses using versions of the 754MAA756 VP4-VP3 processing site containing conservative and nonconservative amino acid substitutions demonstrated that the specificity of the cleavage is dictated by the conserved AA dipeptide.

Amino Acid Sequence↗