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Yun Xiong

Publications and source records attributed to Yun Xiong.

4 recordsLinked to original sources

Effect of remnant-like particle on shear-induced platelet activation and its inhibition by antiplatelet agents.

Remnant-like particles (RLPs) have been reported to promote atherosclerosis and to have effects on platelet function. We studied the effects of RLP on shear-induced platelet activation and their inhibition by antiplatelet agents in vitro. RLP were separated using two monoclonal antibodies, anti apo B-100 and anti apo A-I. These RLP fractions were added to whole blood (WB) or platelet-rich plasma (PRP) in serial dilution of 1, 10 or 100 microg RLP triglyceride (TG) per ml of total sample volume. These samples were incubated, and then stimulated with a high shear stress of 108 dyn/cm(2). Shear-induced platelet aggregation (SIPA) was calculated from the percentage of single platelet loss. P-selectin expression on platelet surface and platelet-derived microparticle (PMP) generation were measured before and after stimulation with shear stress using flow cytometer. SIPA was significantly enhanced by RLP in WB but not in PRP. This enhancing effect was not dose-dependent and was greatest at 10 microg TG/ml. P-selectin expression induced by shear stress was only enhanced by RLP at a concentration of 100 microg TG/ml in both WB and PRP, while generation of PMP induced by shear stress was only enhanced by RLP at a concentration of 100 microg TG/ml in WB. Aspirin inhibited only the enhancement of SIPA by RLPs, while cilostazol inhibited the enhancement of not only SIPA but also p-selectin expression and PMP generation by RLPs.

Antibodies, Monoclonal↗

Structural variation in transition-metal bispidine compounds.

The experimentally determined molecular structures of 40 transition metal complexes with the tetradentate bispyridine-substituted bispidone ligand, 2,4-bis(2-pyridine)-3,7-diazabicyclo[3.3.1]nonane-9-one [M(bisp)XYZ]n+; M = CrIII, MnII, FeII, CoII, CuII, CuI, ZnII; X, Y, Z = mono- or bidentate co-ligands; penta-, hexa- or heptacoordinate complexes) are characterized in detail, supported by force-field and DFT calculations. While the bispidine ligand is very rigid (N3...N7 distance = 2.933 +/- 0.025 A), it tolerates a large range of metal-donor bond lengths (2.07 A < sigma(M-N)/4 < 2.35 A). Of particular interest is the ratio of the bond lengths between the metal center and the two tertiary amine donors (0.84 A < M-N3/M-N7 < 1.05 A) and the fact that, in terms of this ratio there seem to be two clusters with M-N3 < M-N7 and M-N3 > or = M-N7. Calculations indicate that the two structural types are close to degenerate, and the structural form therefore depends on the metal ion, the number and type of co-ligands, as well as structural variations of the bispidine ligand backbone. Tuning of the structures is of importance since the structurally differing complexes have very different stabilities and reactivities.

Journal Article↗