棓丙酯与抗生素联合抗多重耐药鲍曼不动杆菌作用研究

目的 探讨棓丙酯与临床上常用抗生素(头孢他啶、环丙沙星和阿米卡星)对多重耐药鲍曼不动杆菌的联合抑菌作用.方法 根据临床药敏结果选取9株鲍曼不动杆菌多重耐药菌株和鲍曼不动杆菌标准菌株ATCC19606作为实验对象,用棋盘滴定法测定棓丙酯分别与头孢他啶、环丙沙星和阿米卡星的联合抑菌效应.结果 除鲍曼不动杆菌标准菌株外,9株鲍曼不动杆菌多重耐药菌株对三种抗生素皆耐药,棓丙酯对各株细菌均有一定的抑制作用,且对耐药株和标准菌株的最低抑菌浓度(MIC)基本相同;棓丙酯分别与头孢他啶、环丙沙星、阿米卡星联用后抑菌作用表现为相加.结论 棓丙酯对鲍曼不动杆菌生长具有抑制作用,与抗生素联用后抗菌活性增加.     

影响薄片法血小板聚集实验的因素

目的:研究常见影响因素对薄片法血小板聚集实验(SPAT)时间的影响.方法:测定下列富含血小板血浆(PRP)的SPAT:①调整血小板计数分别为240,120,60,30和15×109/L的8例健康献血者PRP;②分别在40,35,30,25,20,15,10和5℃条件下恒温30 min的10例健康献血者PRP;③含终浓度为0,10,20,30,40和50g/L的二甲基亚砜(DMSO)并室温放置30 min的10例健康献血者PRP;④在室温放置1,2,3,4 h后的8例健康志愿者服用阿司匹林前后PRP;⑤含浓度分别为0,0.5,1.0,2.0和3.O U/L的肝素或0.1 g/LEDTA的8例健康献血者PRP.结果:①随着血小板计数的降低,SPAT时间逐渐延长;同一供者血小板计数与其SPAT时间呈显著的直线负相关(r=0.996,P=0.004);②温度在20～40℃对SPAT时间无明显影响,但当温度低于20℃时SPAT时间明显延长;③DMSO对SPAT有明显的影响,使SPAT时间明显延长,并呈明显的剂量效应;④血小板标本室温放置1,2,3和4 h SPAT无显著差异(P=0.815);⑤肝素对SPAT时间无明显影响,而0.1 g/L乙二胺四乙酸(EDTA)可完全抑制血小板聚集.结论:血小板计数、所处的温度以及含有DMSO时,均能在一定程度上影响SPAT时间,但是上述因素均不影响血小板最终形成肉眼可见的聚集,且聚集时间仍然在180 s以内.     

挥发性物质丙基苯甲基醚的控制释放装置

设计了一种用不同的塑料膜控制丙基苯甲基醚挥发的装置。其释放为零级模式。释放速率随膜的材料而异,且与膜的厚度成反比。     

表没食子儿茶素没食子酸酯对肝癌细胞增殖的抑制作用研究

目的 探讨表没食子儿茶素没食子酸酯(EGCG)对肝癌细胞HepG2增殖和凋亡的影响及其可能机制.方法 采用不同浓度(0、25、50、100、200、400mg/L)EGCG作用于HepG2细胞,于24、48h后采用MTT方法检测细胞增殖抑制率.以不同浓度(0、50、100、200mg/L)EGCG作用于HepG2细胞,24h后采用流式细胞术检测细胞凋亡率、细胞周期、细胞分裂周期蛋白25A(CDC25A)及Smad3蛋白的表达,RT-PCR检测CDC25A和Smad3 mRNA的表达.结果 MTT检测结果显示,不同浓度EGCG对HepG2细胞均有生长抑制作用,且具有时间和剂量依赖性(P＜0.01).随着EGCG浓度升高,细胞增殖指数(PI)明显降低(P＜0.01),细胞凋亡率明显增高(p＜0.01),CDC25A蛋白和mRNA表达水平下降(p＜0.05),Smad3蛋白和mRNA表达水平上升(p＜0.05).结论 EGCG可能通过下调CDC25A、上调Smad3的表达,抑制HepG2细胞增殖并诱导其凋亡,从而对肝癌细胞起到生长抑制作用.     

HPLC测定绿茶浸出液灌胃动脉粥样硬化大鼠血浆中4个有效成分的含量

目的:建立HPLC测定绿茶浸出液中没食子酸、咖啡因、表儿茶素没食子酸酯、山柰酚在动脉粥样硬化大鼠体内的血药浓度,为动脉粥样硬化的治疗提供参考。方法:动脉粥样硬化大鼠灌胃绿茶浸出液后,分别在不同时间点取血,采用依利特Hypersil ODS2色谱柱(4.6 mm×250 mm,5μm),流动相甲醇(A)-0.03%磷酸水溶液(B)梯度洗脱(0~30 min,10%~43%A;30~43 min,43%~45%A;43~44 min,45%~51%A;44~60 min,51%~53%A;60~70 min,53%~90%A),流速0.7 mL·min~(-1),检测波长278 nm的色谱条件进样分析。结果:没食子酸、咖啡因、表儿茶素没食子酸酯、山柰酚分别在0.255~20.40,0.430~86.00,0.245~19.60,0.270~21.60 mg·L~(-1)内呈良好线性关系,日内和日间精密度RSD均9.0%,提取回收率和方法回收率都87%;酸化后主要药代动力学参数药时曲线下面积(AUC0-t)分别为(8.902±1.235),(198.5±12.5),(7.367±0.412),(4.426±0.251)mg·h·L~(-1),表观分布容积(Vd)分别为(0.990±0.134),(1.409±0.201),(0.501±0.243),(0.029±0.009)L·kg~(-1),达峰时间(T_(max))均为1.5 h。结论:该方法对所测成分的分离度好,适用于测定绿茶浸出液中4个有效成分的血药浓度,为临床预防此类疾病提供一定理论依据。     

Preparation and characterization of hydroxyapatite nanoparticles carrying insulin and gallic acid for insulin oral delivery

Although nanoparticles carriers for oral delivery of insulin have been researched for many years, this method still fails to solve issues with toxicity, biocompatibility, and degradability in the organism. We therefore developed an innovative conjugation system to solve this problem. Nano hydroxyapatite (HAP) particles were used as the core, then polyethylene glycol (PEG) was wrapped onto the surface of hydroxyapatite, and, finally, insulin (INS) and gallic acid (GA) were conjugated with PEG. PEG functionalized HAP was increased the hydrophilicity of the nanoparticles, also protected them from degradation in the gastrointestinal (GI) tract. Most importantly, the in vivo absorption of nanoparticles in rat small intestines revealed that HAP-PEG-GA-INS was absorbed by the small intestine epithelium. The blood glucose of the type 1 diabetes (T1D) rats that were given intragastrically HAP-PEG-GA-INS showed an obvious downward trend. Overall, we synthesized a safe, non-toxic, and effective oral insulin delivery system.     

Potassium channels underlie postsynaptic but not presynaptic GABA(B) receptor-mediated inhibition on ventrolateral periaqueductal gray neurons

γ-Aminobutyric acid (GABA) is the principle inhibitory neurotransmitter in adult mammalian brain. GABA receptors B subtype (GABA(B)Rs) are abundantly expressed at presynaptic and postsynaptic neuronal structures in the rat ventrolateral periaqueductal gray (PAG), an area related to pain regulation. Activation of GABA(B)Rs by baclofen, a selective agonist, induces presynaptic inhibition by decreasing presynaptic glutamate release. At the same time, baclofen induces a postsynaptic inhibitory membrane current or potential. We here report that in the ventrolateral PAG, the postsynaptic inhibition is mediated by activation of G protein-coupled inwardly rectifying K(+) (GIRK) channels. Blockade of K(+) channels largely prevents postsynaptic action of baclofen. In contrast, presynaptic inhibition of baclofen is insensitive to K(+) channel blockade. The data indicate that potassium channels play different roles in GABA(B)R-mediated presynaptic and postsynaptic inhibition on PAG neurons.