Evaluation of affinity interaction between small molecules and platelets by open tubular affinity capillary electrochromatography

In this paper, an open tubular affinity capillary electrochromatography (OT‐ACEC) was developed by physical adsorption of rabbit platelets on the inner surface of capillary. The interactions between small molecules include adenosine diphosphate (ADP) (positive control), protocatechuic acid (negative control) and seven natural products (salvianolic acid B, salvianic acid A sodium, hydroxysafflor yellow A, ferulic acid, chlorogenic acid, sinapic acid, caffeic acid) and platelets were evaluated by their retention factors and binding constants obtained based on peak‐shift assay. Then, the activities of anti‐platelet aggregation induced by thrombin (THR), ADP and arachidonic acid (AA) for those small molecules (except ADP) were evaluated by turbidimetric method. The results indicate that: (i) ADP, a platelet aggregation inducer, had strong interaction with platelet, while protocatechuic acid that had no inhibition on platelet aggregation behaved no specific interaction; (ii) there was a positive correlation between the anti‐platelet aggregation activities of small molecules and their interactions with platelet, generally those compounds with higher binding constants with platelet exhibited higher activities. Therefore, the OT‐ACEC method developed in the present study can be a potential method to evaluate affinity interactions between small molecules and platelets, so as to predict the biological activities such as anti‐platelet aggregation for the small molecules.     

Development of an Injectable Calcium Phosphate/Hyaluronic Acid Microparticles System for Platelet Lysate Sustained Delivery Aiming Bone Regeneration

Despite the biocompatibility and osteoinductive properties of calcium phosphate (CaP) cements their low biodegradability hampers full bone regeneration. Herein the incorporation of CaP cement with hyaluronic acid (HAc) microparticles loaded with platelet lysate (PL) to improve the degradability and biological performance of the cements is proposed. Cement formulations incorporating increasing weight ratios of either empty HAc microparticles or microparticles loaded with PL (10 and 20 wt%) are developed as well as cements directly incorporating PL. The direct incorporation of PL improves the mechanical properties of the plain cement, reaching values similar to native bone. Morphological analysis shows homogeneous particle distribution and high interconnectivity between the HAc microparticles. The cements incorporating PL (with or without the HAc microparticles) present a sustained release of PL proteins for up to 8 d. The sustained release of PL modulates the expression of osteogenic markers in seeded human adipose tissue derived stem cells, thus suggesting the stimulatory role of this hybrid system toward osteogenic commitment and bone regeneration applications.

     

Mechanical model for staggered bio-structure

A generic mechanical model for bio-composites, including stiff platelets arranged in a staggered order inside a homogeneous soft matrix, is proposed. Equations are formulated in terms of displacements and are characterized by a set of non-dimensional parameters. The displacements, stress fields and effective modulus of the composite are formulated. Two analytical models are proposed, one which includes the shear deformations along the entire medium and another simplified model, which is applicable to a slender geometry and yields a compact expression for the effective modulus. The results from the models are validated by numerical finite element simulations and found to be compatible with each other for a wide range of geometrical and material properties. Finally, the models are solved for two bio-structures, nacre and a collagen fibril, and their solutions are discussed.     

A cellular scale numerical study of the effect of mechanical properties of erythrocytes on the near-wall motion of platelets

The effect of mechanical properties of erythrocytes on the near-wall motion of platelets was numerically studied with the immersed boundary method. Cells were modeled as viscous-fluid-filled capsules surrounded by hyper-elastic membranes with negligible thickness. The numerical results show that with the increase of hematocrit, the near-wall approaching of platelets is enhanced, with which platelets exhibit larger deformation and orientation angle of its near-wall tank-treading motion, and the lateral force pushing platelets to the wall is increased with larger fluctuation amplitude. Meanwhile the near-wall approaching is reduced by increasing the stiffness of erythrocytes.     

高效薄层扫描法测定蛛网膜下腔出血患者脑脊液中血小板活化因子

摘要：建立了测定蛛网膜下腔出血患者（SAH）脑脊液中血小板活化因子（PAF）质量浓度的高效薄层扫描方法。薄层板为高效硅胶G板（100mm×l00mm）,展开剂为V（氯仿）:V（甲醇）:V（水）=65:35:6,下层液展开,显色剂为100g/L磷钼酸溶液,展开距90mm,扫描波长630nm。方法的线性范围0.5～2.5μg/L,相关系数0.9990,最小检测质量浓度50ng/L,平均回收率98.6％。运用所建立的方法测定了16例SAH患者发病后脑脊液和10例非神经系统疾病患者脑脊液中PAF的质量浓度及其变化     

机采血小板输注治疗血小板严重减少的疗效观察

目的：观察血细胞分离机单个供者血小板（SDP）治疗血小板严重减少出血的疗效，方法：36例因各种血液疾病致血小板严重减少合并皮肤粘膜，内脏出血者输注SDP，与同期住宅的16例血液病合并出血作为对照，结果：治疗组显效14例，有效17例，无效5例，与对照组显效2例，有效3例，无效11例比较著性差异P＜0．001。结论：机采血小板输注作为抢救各种血液合并严重血小板减少出血疗效果，且具有产量高，纯度高，白细胞污染率低，单一的免疫特征可显著降低血小板输注无效。     

Synthesis of cationic ether lipids of alkyl type with short-chain substituents at the 2-position of the glycerol backbone

A series of cationic ether lipids with short-chain substituents at the 2-position and various cationic groups attached directly or through a spacer group to the glycerol backbone was synthesized.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1826–1830, October, 1994.This work was supported by the Russian Foundation for Basic Research (Project No. 94-03-08-166).     

Effect of the Esters of Gallic Acid on Model and Human Blood Platelet Membranes Studied by Fourier Transform Infrared Spectroscopy

Gallic acid is one of the components of Chinese herbal drug Radix paeoniae used for promoting blood circulation to remove blood stasis. This paper studied the effects of gallic acid and its esters (e.g. ethyl, propyl, isobutyl and butyl gallate) on model and human blood platelet membranes by FTIR which was used for monitoring the physical state of the acyl chain, interfacial and head group region of the membrane lipid bilayer. From the experimental results it can be seen that the gallic acid and its esters have the modifying function on the pure and cholesterol-containing DPPC model membranes, and have the quantity-effective and structural-effective relationships. In addition, it is discovered that these esters have the modifying effect on the structure of human blood platelet membrane and can reverse the effect of ADP. That the effect of the esters of gallic acid counteracts the effect of cholesterol and ADP on human blood platelet perhaps provides a new explanation of the mechanism of Chinese herbal d     

Force measurements on platelet surfaces with high spatial resolution under physiological conditions

Investigations on platelets are essential to understanding the regulation of hemostasis and thrombosis. Activated platelets undergo dramatic conformational and morphological changes mediated by numerous plasma proteins. AFM techniques can combine high spatial resolution with measurements of the mechanical properties of platelet surfaces. Here, we demonstrate two-dimensional force mapping over a human platelet adsorbed on glass under physiological buffer. The best resolution of platelet membrane elasticity we obtained was at 15.6×15.6 nm² pixel⁻¹. In addition, quantitative information on platelet surface charge density was extracted from individual force curves with the aid of DLVO theory.     

NLR、hs-CRP、MPV与肥胖、非肥胖型PCOS的关系

目的探究中性粒细胞/淋巴细胞比值（NLR）、超敏C反应蛋白（hs-CRP）、血小板平均体积（MPV）与肥胖、非肥胖型多囊卵巢综合征（PCOS）的关系。方法对112例PCOS患者（肥胖型68例,非肥胖型44例）和年龄、BMI配对的90例健康体检女性（健康对照组肥胖型47例,非肥胖型43例）,检测并比较两组及亚组之间MPV、NLR、hs-CRP、生殖内分泌激素及代谢指标。结果PCOS组血清空腹血糖水平（FPG）、空腹胰岛素（FINS）、稳态胰岛素评价指数（HOMA-IR）、NLR、hs-CRP、MPV水平均明显高于健康对照组（均P＜0.05）。肥胖型PCOS组NLR、hs-CRP、MPV高于肥胖型健康对照组（均P＜0.05）。肥胖型PCOS组NLR、hs-CRP、MPV均高于非肥胖型PCOS组（均P＜0.05）。NLR、hs-CRP、MPV的AUC及95%CI分别为0.819（0.763~0.903）、0.982（0.959~1.000）、0.906（0.848~965）。结论肥胖型PCOS患者血清NLR、hs-CRP、MPV水平明显升高,这些指标的变化对肥胖型PCOS代谢异常有较强的诊断价值。