16 research outputs found

    Molluscicidal activity of affinin and other isobutylamides from the asteraceae

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    Unsaturated aliphatic isobutylamides from Asteraceae, Rutaceae and Piperaceae are potential agents to control schistosomiasis. Affinin (N-isobutyl-2,6,8-decatrienamide) from Heliopsis longipes has strong molluscicidal activity against Physa occidentalis (50 ca 100 [mu]M) and the cercariae of the fluke. The amide has also been shown to be present in Wedelia parviceps flowers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24159/1/0000417.pd

    Assisted evolution enables HIV-1 to overcome a high trim5α-imposed genetic barrier to rhesus macaque tropism

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    Diversification of antiretroviral factors during host evolution has erected formidable barriers to cross-species retrovirus transmission. This phenomenon likely protects humans from infection by many modern retroviruses, but it has also impaired the development of primate models of HIV-1 infection. Indeed, rhesus macaques are resistant to HIV-1, in part due to restriction imposed by the TRIM5α protein (rhTRIM5α). Initially, we attempted to derive rhTRIM5α-resistant HIV-1 strains using two strategies. First, HIV-1 was passaged in engineered human cells expressing rhTRIM5α. Second, a library of randomly mutagenized capsid protein (CA) sequences was screened for mutations that reduced rhTRIM5α sensitivity. Both approaches identified several individual mutations in CA that reduced rhTRIM5α sensitivity. However, neither approach yielded mutants that were fully resistant, perhaps because the locations of the mutations suggested that TRIM5α recognizes multiple determinants on the capsid surface. Moreover, even though additive effects of various CA mutations on HIV-1 resistance to rhTRIM5α were observed, combinations that gave full resistance were highly detrimental to fitness. Therefore, we employed an 'assisted evolution' approach in which individual CA mutations that reduced rhTRIM5α sensitivity without fitness penalties were randomly assorted in a library of viral clones containing synthetic CA sequences. Subsequent passage of the viral library in rhTRIM5α-expressing cells resulted in the selection of individual viral species that were fully fit and resistant to rhTRIM5α. These viruses encoded combinations of five mutations in CA that conferred complete or near complete resistance to the disruptive effects of rhTRIM5α on incoming viral cores, by abolishing recognition of the viral capsid. Importantly, HIV-1 variants encoding these CA substitutions and SIVmac239 Vif replicated efficiently in primary rhesus macaque lymphocytes. These findings demonstrate that rhTRIM5α is difficult to but not impossible to evade, and doing so should facilitate the development of primate models of HIV-1 infection

    Innate immunity against HIV: a priority target for HIV prevention research

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    This review summarizes recent advances and current gaps in understanding of innate immunity to human immunodeficiency virus (HIV) infection, and identifies key scientific priorities to enable application of this knowledge to the development of novel prevention strategies (vaccines and microbicides). It builds on productive discussion and new data arising out of a workshop on innate immunity against HIV held at the European Commission in Brussels, together with recent observations from the literature

    Human cellular restriction factors that target HIV-1 replication

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    Recent findings have highlighted roles played by innate cellular factors in restricting intracellular viral replication. In this review, we discuss in brief the activities of apolipoprotein B mRNA-editing enzyme 3G (APOBEC3G), bone marrow stromal cell antigen 2 (BST-2), cyclophilin A, tripartite motif protein 5 alpha (Trim5α), and cellular microRNAs as examples of host restriction factors that target HIV-1. We point to countermeasures encoded by HIV-1 for moderating the potency of these cellular restriction functions

    Host restriction factors in retroviral infection: promises in virus-host interaction

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    A new and unusual host plant record for the rare moth Lasionycta wyatti (Lepidoptera: Noctuidae)

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    Moths reared from larvae collected from sand around the bases of silver burweed (Ambrosia chamissonis [Less.] Greene) at Tsawwassen, BC were identified as the rare noctuid Lasionycta wyatti (Barnes & Benjamin) Thiarubrines, toxic secondary compounds produced by A. chamissonis, are well tolerated by these larvae. This constitutes a new host plant record for the species.Keywords: Lasionycta; Ambrosia; thiarubrines; insect-plant chemical interactio

    Actividad antimicrobiana y estudio fitoquĂ­mico preliminar de Mandevilla veraguasensis (Seem.) Helms. (Apocynaceae)

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    Ethyl acetate extract from leaves of Mandevilla veraguasensis (Seem.) Hemsl. (Apocynaceae) has been assayed for antibacterial and antifungal activity. A moderate activity against Gram positive bacteria Bacillus subtilis, Enterococcus faecalis and Staphylococcus aureus, which can be in part attributed to the flavonoids 4´-O-methyl-kaempferol (I) and quercetin (II) isolated from this extract, was observed
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