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61.
Effects of resveratrol on human immune cell function. 总被引:15,自引:0,他引:15
Resveratrol (3,5,4'-trihydroxystilbene), a polyphenol found in grapes and grape products such as red wine, has been reported to exhibit a wide range of biological and pharmacological activities both in vitro and in vivo. Because many of the biological activities of resveratrol, like the inhibition of cyclooxygenase, induction of CD95 signaling-dependent apoptosis, effects on cell division cycle and modulation of NF-kB activation, suggest a possible effect on the immune system, we evaluated the in vitro effects of resveratrol in three immune response models: i) development of cytokine-producing CD4+ and CD8+ T cells induced by stimulation of peripheral blood mononuclear cells (PBMC) with anti-CD3/anti-CD28; ii) specific antigen-induced generation of cytotoxic T lymphocytes; iii) natural killer (NK) activity of PBMC. The results showed that in vitro exposure to resveratrol produces a biphasic effect on the anti-CD3/anti-CD28-induced development of both IFN-gamma- IL2- and IL4-producing CD8+ and CD4+ T cells, with stimulation at low resveratrol concentrations and suppression at high concentrations. Similarly, the compound was found to induce a significant enhancement at low concentrations and suppression at high concentrations of both CTL and NK cell cytotoxic activity. On the whole, the results of the study indicate that resveratrol modulates several human immune cell functions and suggest that this activity may be related to its effects on cytokine production by both CD4+ and CD8+ T cells. 相似文献
62.
An exception to the generally conservative nature of plastid gene evolution
is the gene coding for the beta" subunit of RNA polymerase, rpoC2. Previous
work by others has shown that maize and rice have an insertion in the
coding region of rpoC2, relative to spinach and tobacco. To assess the
distribution of this extra coding sequence, we surveyed a broad
phylogenetic sample comprising 55 species from 17 angiosperm families by
using Southern hybridization. The extra coding sequence is restricted to
the grasses (Poaceae). DNA sequence analysis of 11 species from all five
subfamilies within the grass family demonstrates that the extra sequence in
the coding region of rpoC2 is a repetitive array that exhibits more than a
twofold increase in nucleotide substitution, as well as a large number of
insertion/deletion events, relative to the adjacent flanking sequences. The
structure of the array suggests that slipped-strand mispairing causes the
repeated motifs and adds to the mechanisms through which the coding
sequence of plastid genes are known to evolve. Phylogenetic analyses based
on the sequence data from grass species support several relationships
previously suggested by morphological work, but they are ambiguous about
broad relationships within the family.
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