丹酚酸对缺血性心脏病的作用及作用机制研究进展

丹酚酸为唇形科植物丹参的最主要的水溶性活性成分,具有多种药理作用,被广泛应用于防治心血管疾病。本文通过查阅国内外最新研究文献,对丹酚酸防治缺血性心脏病的作用及作用机制进行综述,并介绍了丹酚酸A和丹酚酸B等丹参的主要水溶性成分通过保护血管内皮、舒张冠状动脉、促进血管再生、抗血小板聚集、抑制炎性反应、抗细胞凋亡和清除自由基等多角度防治缺血性心脏病的作用机制,为进一步研究丹酚酸对缺血性心脏病的作用及药物研发提供理论依据。     

Combined Freeze-Thaw and Chloride Attack Resistance of Concrete Made with Recycled Brick-Concrete Aggregate

The objective of this study was to investigate the physico-chemical properties of concrete made with recycled brick-concrete aggregate, which was the mixture from waste concrete and waste clay brick in a 7:3 ratio. Specifically, this paper investigated the mechanical properties, freeze-thaw resistance, and distribution of water-soluble chloride ions of concrete containing RBCA and fly ash (FA) against combined freeze-thaw and sodium chloride attack. Concrete containing RBCA replacement of natural coarse aggregate and fly ash replacement of Portland cement was subjected to 45 freeze-thaw cycles containing sodium chloride solution. It was discovered that the mechanical properties and freeze-thaw resistance to sodium chloride attack gradually decreased with increasing RBCA content. At the same time, a replacement level of 15% FA by weight resulted in significant improvements in compressive strength and resistance to combined freeze-thaw and chloride attack. Furthermore, using a replacement of 30% FA by weight markedly improved the resistance to chloride ion penetration of concrete due to the lowest water-soluble chloride content.     

水溶性壳聚糖对3T3TK成纤维细胞生长及表型的影响

目的：本研究利用成纤维细胞作为肌腱修复组织工程的种子细胞,采用可降解的壳聚糖作为生物材料,明确水溶性壳聚糖对3T3TK成纤维细胞生长及表型的影响,为后续研究奠定基础。方法：3T3TK成纤维细胞常规培养,采用CellTilter-GloTM细胞活力测试盒检测不同浓度壳聚糖对成纤维细胞活力的影响;运用羟脯氨酸、碱性磷酸酶(ALP)试剂盒分别检测细胞培养上清液的胶原含量与碱性磷酸酶的含量。结果：不同浓度壳聚糖组与阴性对照组相比,其发光信号值均无显著差异(P＞0．05);0．1%和0．01%浓度壳聚糖组细胞培养上清液中的羟脯氨酸含量以及胶原含量与阴性对照组相比均有显著差异(P＜0．01),随壳聚糖浓度的上升,胶原含量下降,呈剂量依赖;与阴性对照组相比,各浓度壳聚糖组细胞培养上清液中ALP活性均无显著差异。结论：水溶性壳聚糖并不明显抑制3T_3TK成纤维细胞的活力,但能使其分泌胶原的量显著减少,提示壳聚糖具有作为肌腱修复的组织工程材料,并抑制肌腱修复中粘连形成的潜力。     

非晶固体分散体技术的研究现状

提高药物的溶解度和生物利用度是制剂研究的重要挑战.非晶固体分散体(ASD)能极大增加药物的溶解度和溶出速度,从而改善其生物利用度,被广泛用于难溶性药物的递送.ASD的成功必须满足两点要求:良好的物理稳定性以及良好的溶出以获得较高的生物利用度.本文主要综述ASD的制备方法,表征技术,物理稳定性以及制剂设计理论,以期为AS...     

香烟烟雾水溶物对人外周血淋巴细胞SCE的影响

SCE频率分析是研究环境诱变剂和致癌剂引起人类遗传物质损伤的有效手段。本文以人外周血淋巴细胞姐妹染色单体交换(SCE)为指标,研究了香烟烟雾水溶物对体外培养的人外周血淋巴细胞SCE的影响。结果表明香烟烟雾水溶物引起人的外周血淋巴细胞SCE数的增加,证明香烟烟雾水溶物具有诱发突变作用。     

板蓝根水溶性化学成分的研究

目的:提取、分离、鉴定板蓝根水溶性化学成分。方法:板蓝根水提取液上HP-20大孔吸附树脂,不同浓度乙醇梯度洗脱,洗脱部分经硅胶、凝胶、反相硅胶柱色谱反复分离、纯化,利用波谱技术确定化合物的结构。结果:从板蓝根水提取液中分离得到6个化合物,分别鉴定为(+)-异落叶松树脂醇(1)、落叶松树脂醇-4-O-β-D-吡喃型葡萄糖苷(2)、落叶松树脂醇-4,4′-二-O-β-D-吡喃型葡萄糖苷(3)、表告依春(4)、吲哚-3-乙腈-6-O-β-D-葡萄糖苷(5)、4-羟基-3-吲哚醛(6)。结论:化合物(6)为首次从该植物中分离得到。     

Polyanhydride Mierospheres that Display Near-Constant Release of Water-Soluble Model Drug Compounds

A new method to prepare polyanhydride microspheres capable of near-constant sustained release of low molecular weight, water-soluble molecules is presented. The polyanhydrides used were poly-(fatty acid dimer) (PFAD), poly(sebacic acid) (PSA), and their co-polymers [P(FAD-SA)]. Acid orange 63 (AO), acid red 8 (AR), and p-nitroaniline, were used as model release molecules. P(FAD-SA) microspheres containing the molecules with or without gelatin were prepared by a modified solvent evaporation method using a double emulsion. The microspheres were spherical with diameters of 50–125 µm and encapsulated more than 85% of the molecule, irrespective of the compound used. Near-zero-order degradation kinetics were observed for 5 days as judged by sebacic acid (SA) release. Microsphere degradation was pH sensitive, being enhanced at high pH, and became more stable in acidic conditions, irrespective of the incorporation of gelatin in the matrix. For the gelatin-free microspheres, a close correlation of SA release and AO release was observed (2% loading), suggesting a release mechanism that was controlled dominantly by degradation. However, the incorporation of gelatin into the microsphere significantly extended the periods of molecule release from P(FAD-SA) microspheres, although the degradation profile of the microspheres themselves was quite similar to that of gelatin-free microspheres. It is possible that an interaction between FAD monomers and gelatin molecules causes continued release, even after the polymer matrix completely degrades (even after complete degradation, FAD monomers remain because of their poor water solubility). Thermal analysis of polyanhydride microspheres at different degradation stages demonstrated that a crystalline structure was formed between gelatin and the FAD monomers produced with microsphere degradation. This gelatin effect on the extended period of drug release was not observed for microspheres prepared from other polyanhydrides: poly (sebacic acid) and its co-polymer of bis(p-carboxyphenoxy) propane and sebacic acid. It is therefore likely that the crystalline structure formed between gelatin and FAD monomers may function as a reservoir for water-soluble drugs, leading to an extended period of molecule release from the gelatin-loaded P(FAD-SA) microspheres.     

人工神经网络预测HPMC缓释片中易溶性药物的释放

目的应用BP人工神经网络模型预测水溶性药物从HPMC缓释片中的释放。方法以6种不同溶解性的水溶性药物(对乙酰氨基酚、氧氟沙星、盐酸环丙沙星、乳酸左氧氟沙星、多索茶碱、氯苯那敏、维拉帕米)为模型药物,设计62个处方,其中前面55个处方作为训练处方,另外7个处方作为验证处方,压制HPMC缓释片,进行释放度检查。以溶解度、载药量、HPMC的量、HPMC的固有黏度、MCC的量、PVP的浓度和药物溶出仪的转速作为自变量,药物在各个取样时间点的累积释放量作为输出,建立BP人工神经网络模型,并与响应面法进行对照,通过线性回归法和相似因子法比较人工神经网络和响应面法的预测能力,借助三维图说明各个变量对药物释放的影响。结果线性回归和相似因子法表明人工神经网络较响应面法的预测值与实际测定值更吻合,更能充分地说明单因素对药物释放的影响规律。结论人工神经网络可以代替响应面法处理HPMC缓释片处方设计中的不同溶解度的水溶性药物的多因素多响应的非线性问题而且可以推广到别的制剂设计中。     

Improvement of bioavailability and photostability of amlodipine using redispersible dry emulsion

To improve the bioavailability and photostability of poorly water-soluble and photosensitive amlodipine, dry emulsion (DE) was prepared by spray-drying the oil-in-water emulsion of amlodipine. Labrafil M 1944 CS and dextrin were employed as oil phase and matrix material, respectively. Dispersing DE in distilled water formed an emulsion with a mean droplet size 1.4-fold larger than that of the homogenized amlodipine emulsion before spray-drying (0.24 ± 0.30 μm versus 0.17 ± 0.02 μm). The mean droplet size of DE remained unchanged during 6-month storage at room temperature. 94.4% versus 33.1% of amlodipine remained intact after 24-h UV irradiation of amlodipine as DE formulation or as powder. These data suggest that DE formulation greatly improved the photostability of amlodipine, as well as increasing the physical stability of emulsion systems. In vitro release of DE was higher than that of amlodipine powder (66% versus 48% release at 60 min). Consequently, DE formulation resulted in 2.6- and 2.9-fold higher C_max and AUC_0–24 h of amlodipine compared after oral administration of amlodipine powder in rats. Our data suggest that the DE may be a potential oral dosage form for amlodipine to improve its bioavailability.     

Effect of aging on the water-soluble and water-insoluble protein pattern in normal human lens

Total extracts of both water-soluble and water-insoluble portions are obtained from fetal and adult human lenses. In the water-soluble extracts of lenses older than 14 years of age little difference is seen between the cortical and nuclear preparations. In lenses older than 14 years a polypeptide chain of approximately 10 k appears. In fetal and newborn lenses a 43 k polypeptide is detected which becomes more diffuse upon aging. Concomitant with a decrease of a 29·5 k polypeptide, there is a relative increase of a 29 k chain, suggesting a situation comparable with the transition from calf βB_1a to βB_1b. In young lenses a major β-polypeptide co-migrating with calf βB_p is seen.As for the water-insoluble portions, no difference between cortical and nuclear preparations is detectable after 14 years of age. In fetal lens there is a high amount of the 29·5 k polypeptide, which decreases with aging and finally disappears. Till 6 months four bands with molecular weights of 200 k, 100 k, 57 k and 43 k are detected, co-migrating with calf myosin, α-actinin, vimentin and actin, respectively.