ß-L-Arabinofuranosylation Conducted by 5-O-(2-pyridinecarbonyl)-L-arabinofuranosyl Trichloroacetimidate.

We describe a ß-L-arabinofuranosylation method by employing the 5-O-(2-pyridinecarbonyl)-L-arabinofuranosyl trichloroacetimidate 10 as a donor. This approach allows a wide range of acceptor substrates, especially amino acid acceptors, to be used. Stereoselective synthesis of ß-(1,4)-L-arabinofuranosyl-(2S, 4R)-4-hydroxy-L-proline (ß-L-Araf-L-Hyp4) and its dimer is achieved readily by this method. Both the stereoselectivities and yields of the reactions are excellent. To demonstrate the utility of this methodology, the preparation of a trisaccharide in a one-pot manner was carried out.

Tanshinone II A inhibits dendritic cell-mediated adaptive immunity: potential role in anti-atherosclerotic activity.

OBJECTIVE: Antigen-presenting cells such as monocytes and dendritic cells (DCs) stimulate T-cell proliferation and activation during adaptive immunity. This cellular interaction plays a role in the growth of atherosclerotic plaques. Tanshinone II A (TSN) had been shown to decrease the growth of atherosclerotic lesions. We therefore investigated the ability of TSN to inhibit human monocyte-derived DCs and their T-cellstimulatory capacity. METHODS: DCs derived from human monocytes cultured with recombinant human interleukin (IL)-4 and recombinant human granulocyte-macrophage colony-stimulating factor were co-cultured with TSN and lipopolysaccharide for 48 h. Phosphate-buffered saline was used as a negative control. Activation markers and the capacity of DCs for endocytosis were measured by flow cytometry, and proinflammatory cytokines were measured by enzyme-linked immunosorbent assays. DCs were co-cultured with lymphocytes to measure T-cell proliferation and IL-2 secretion by mixed lymphocyte reactions. RESULTS: TSN dose-dependently attenuated DC expression of costimulatory molecules (CD86), and decreased expression of major histocompatibility complex class II (human loukocyte antigen-DR) and adhesion molecules (CD54). Moreover, TSN reduced secretion of the proinflammatory cytokines IL-12 and IL-1 by human DCs, and restored the capacity for endocytosis. Finally, TSN-preincubated DCs showed a reduced capacity to stimulate T-cell proliferation and cytokine secretion. CONCLUSIONS: TSN inhibits DC maturation and decreases the expression of proinflammatory cytokines, while impairing their capacity to stimulate T-cell proliferation and cytokine secretion. These effects may contribute to the influence of TSN on the progression of atherosclerotic lesions.

[Morphological characteristics of internal carotid artery atherosclerotic lesions in digital subtracted angiography].

OBJECTIVE: To illustrate the morphological characteristics of atherosclerotic lesions of the internal carotid artery. METHODS: The morphological characteristics of cervicocerebral atherosclerotic lesions in digital subtracted angiography were retrospectively reviewed in 120 cases. RESULTS: Totally 217 atherosclerotic lesions were detected. Of all the lesions, moderately and severely stenosed lesions accounted for 62.21% and mild stenosed lesions for 37.79%; long lesions were found in 18.89% and short ones in 81.11%; 37.33% of the lesions were ulcerated while 62.67% were non-ulcerated; 13.36% were angulated lesions and 86.64% non-angulated; 50.23% were eccentric lesions and 49.77% were concentric; lesions with adjacent artery dilation were found in 9.22%, and lesions without with adjacent artery dilation in 90.78%. CONCLUSION: The atherosclerotic lesions are characterized by moderate to severe stenosis and non-ulcerated, non-angulated, eccentric lesions without adjacent artery dilation.