PubMed Health⌕ Search

Biomedical subjects

A J Barbera

Publications and source records attributed to A J Barbera.

4 recordsLinked to original sources
PubMed2001

The Kaposi' s sarcoma-associated herpesvirus latency-associated nuclear antigen.

Kaposi's sarcoma-associated herpesvirus (KSHV), also called human herpesvirus 8 (HHV-8), is associated with Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (6,7,10). While the vast majority of tumor cells from these malignancies are latently infected, only a small subset of viral genes are actually expressed (5,40,47). Of these genes, the latency-associated nuclear antigen (LANA-1, LNA, or LNA1) is the only protein consistently shown to be highly expressed by in situ hybridization and immunohistochemistry (11,20,21,32). Moreover, within the past few years LANA-1 has proven to be a quite versatile protein, playing not only a pivotal role in KSHV episome persistence, but also in interacting with and influencing several cellular genes.

Animals↗
PubMed1975

A molecular approach to retinotectal specificity.

An assay is described to examine the hypothesis that retinal neurons adhere preferentially to that part of the optic tectum near theri normal synaptic termini. The method measures the adherence of isotopically labelled cell bodies from either the dorsal or ventral half of the neural retina of chick embryos to dorsal and ventral tectum halves. When a labelled cell suspension is prepared from a dorsal half-retina, more cells adhere to the ventral half of the tectum. When the cells are from the ventral part of the retina, more bind to the dorsal half of the tectum. This preferential adhesion mimics the retinotectal projection found in vivo and supports an interpretation of neuronal specificity dependent on cell surface adhesive properties. Molecular mokels are presented that utilize glycosyltransferases and their substrates as the basis for adhesive recognition. Two of these models suggest that quantitative changes in the distribution of transferases and their substrates determine retinotectal specificity. The third proposes qualitative variations in these molecules across the retina and tectum.

Animals↗
PubMed1973

Adhesive recognition and retinotectal specificity.

An assay has been developed to test the hypothesis that neurons from a limited area of the retina will adhere preferentially to that part of the optic tectum near their normal synaptic termini. The method measures the adherence of (32)P-labeled cell bodies from either the dorsal or ventral half of the neural retina of chick embryos to dorsal and ventral tectal halves. When a labeled, single-cell suspension is prepared from dorsal half-retina, more cells bind to the ventral half of the tectum. When the labeled cells are from ventral half-retina, more bind to dorsal half-tecta. This preferential adhesion mimics the retinotectal projection found in vivo. Dorsal retinal cells show this preference shortly after dissociation with crude trypsin, and maintain it for at least 9 hr. Ventral retinal cells, however, require incubation in nutrient medium after trypsinization in order to display this selectivity. Comparable results are obtained when the cell suspension is prepared from pigmented retina. The data support an interpretation of neuronal specificity dependent on cell-surface interactions and demonstrate a clear correlation between selective adhesion and biological function.

Animals↗