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N Richard

Publications and source records attributed to N Richard.

25 records · Page 2Linked to original sources
PubMed1994

HIV-1 Rev is capable of shuttling between the nucleus and cytoplasm.

The mechanism by which Rev facilitates the export, and consequently, the translation of the structural protein mRNAs of the human immunodeficiency virus type 1 remains undefined. Previous immunolocalization has determined that Rev is predominantly in the nucleus with significant accumulation in the nucleolus, a localization consistent with the assumed site of Rev action. To determine whether the subcellular distribution is more dynamic than what was indicated by the original studies, the capacity of Rev to shuttle between the nucleus and cytoplasm was examined. It was observed that treatment of cells with DRB or actinomycin D resulted in a dramatic alteration in Rev distribution, the majority of the protein being found in the cytoplasm. Removal of the drug resulted in a rapid accumulation of Rev in the nucleus indicating that the block to nuclear import was reversible. Subsequent studies indicated that the movement of Rev into the cytoplasm was a passive process while its accumulation in the nucleus was an active one, given that only the latter displayed sensitivity to temperature. Finally, it was demonstrated that, while extensive redistribution of Rev could be attained by inhibition of RNA polymerase I alone, Rev was still capable of inducing expression of HIV structural gene expression under these conditions. Consequently, Rev activity does not appear to be dependent on either an intact nucleolus or the accumulation of the protein in the nucleus.

Biological Transport↗
PubMed1994

NURSETALK: the latest addition to the information highway.

NURSETALK is an electronic bulletin board system (BBS) developed to provide information and meet the communication needs of three different nursing organizations in North Carolina. It was designed and conceptualized from a user perspective to promote functionality and acceptance.

North Carolina↗
PubMed1986

Molecular characterization of antibodies bearing Id-460. I. The structure of two highly homologous VH genes used to produce idiotype positive immunoglobulins.

The heavy chain immunoglobulin genes encoding a variety of antibodies specific for DNP or Pasteurella pneumotropica and bearing the dominant idiotype of MOPC 460, Id-460, were cloned and sequenced. The VH genes encoding the M460 and D35 (DNP binding) antibodies were found to be homologous but not identical to the VH gene encoding the LB8 (P. pneumotropica binding) monoclonal antibody. Two of at least eight genes in the VH460 cross-hybridizing gene family can encode Id-460 positive antibodies. The VH460 gene family overlaps with the gene family described by VH36-60 and more completely describes this germ-line VH gene family. We have previously demonstrated a genetic requirement for VK1 expression in order to observe the expression of Id-460 in anti-DNP antibody responses. Southern blot analysis of these monoclonal antibody-producing cells demonstrates, as with the cross-hybridizing VH, that two cross-hybridizing VK1 genes (VK1A and VK1C) can be used to encode Id-460-positive immunoglobulins. We demonstrate that immunoglobulin idiotype determinant expression can be the result of the expression of nonidentical but highly homologous genes in the VH460 cross-hybridizing VH gene family and also in the VK1 cross-hybridizing VL family.

Animals↗
PubMedDate not supplied

Resistance profiles of (+)2'-deoxy-3'-oxa-4'-thiocytidine and (-)2'-deoxy-3'-oxa-4'-thio-5-fluorocytidine.

Resistant variants were selected in vitro against two novel nucleoside analogues, (+) dOTC and (-) dOTFC using the HIV-1 molecular clone HXB2D. The variants obtained displayed 6.5-fold and 10-fold resistance to these compounds, respectively. Cloning and sequencing of the RT genes of the selected viruses identified two mutations, M184I for (+) dOTC and M184V for (-) dOTFC. Results with mutated recombinant clones of HXB2D confirmed the importance of these mutations in MT-4 cells. The resistance profiles of clinical samples with wild-type or 3TC-resistant phenotypes were also studied; low to moderate levels of cross-resistance were observed against the novel compounds.

Anti-HIV Agents↗