Neuroprotective effect of gold nanoparticles composites in Parkinson's disease model

Parkinson’s disease (PD) is second most common neurodegenerative disorder worldwide. Although drugs and surgery can relieve the symptoms of PD, these therapies are incapable of fundamentally treating the disease. For PD patients, over-expression of α-synuclein (SNCA) leads to the death of dopaminergic neurons. This process can be prevented by suppressing SNCA over-expression through RNA interference. Here, we successfully synthesized gold nanoparticles (GNP) composites (CTS@GNP-pDNA-NGF) via the combination of electrostatic adsorption and photochemical immobilization, which could load plasmid DNA (pDNA) and target specific cell types. GNP was transfected into cells via endocytosis to inhibiting the apoptosis of PC12 cells and dopaminergic neurons. Simultaneously, GNP composites are also used in PD models in vivo, and it can successfully cross the blood-brain barrier by contents of GNP in the mice brain. In general, all the works demonstrated that GNP composites have good therapeutic effects for PD models in vitro and in vivo.     

A preliminary study investigating the survival of tetracycline resistant Enterococcus faecalis after root canal irrigation with high concentrations of tetracycline

AIM: To compare the ability of two Enterococcus faecalis strains to survive exposure to an irrigation solution containing a high concentration of tetracycline in the root canals of bovine teeth. METHODOLOGY: The root canals of twelve bovine incisor root sections were chemo-mechanically prepared using commercially available drills, sodium hypochlorite and ethylenediamine tetra-acetic acid. The root sections were divided into two groups and inoculated with either a tetracycline sensitive or resistant strain of E. faecalis. The strains are isogenic, however one contains a conjugative transposon related to Tn916 which confers resistance to tetracycline, and the other strain is sensitive to the antibiotic. After 26 days of incubation the root canals were irrigated using one of three solutions (sterile distilled water, 50% ethanol or tetracycline at a concentration of 30 mg mL(-1)). The roots were sampled by grinding dentine and canal contents and the debris collected were incubated in broth to assess growth. RESULTS: Irrigation with sterile distilled water or 50% ethanol did not remove all of the cells present. The tetracycline containing solution was efficient in preventing any growth of sensitive E. faecalis, however the resistant strain was able to survive a 5 min exposure at 30 mg mL(-1). CONCLUSIONS: The presence of the Tn916-like conjugative transposon containing the tetracycline resistance gene tet(M) allowed an E. faecalis strain to survive irrigation using a solution containing an extremely high concentration of tetracycline in a root canal model.     

Refractory chronic periodontitis: effect of oral tetracycline hydrochloride and root planing

Refractory chronic periodontitis of 16 patients was treated by root planing and adjunctive tetracycline hydrochloride therapy. The antibiotic was taken orally one hour before root planing and continued for six days at a dosage of 250 mg six hourly. The clinical data for each patient were recorded as the number of probing depths in each of the 1-3 mm, 4-6 mm and 7-10 mm ranges. The Multivariate Analysis of Variance (MANOVA) procedure for repeated measurements was used to analyse the data. The results demonstrated that the number of sites with probing depths of 4-6 mm and 7-10 mm associated with incisors, canines, premolars and molars decreased with a corresponding increase in the number of sites in the 1-3 mm range. Incisor and canine teeth showed a better response to treatment than premolars, which responded better than molars. The cases were followed for varying periods of time from six months to two years following antibiotic therapy. The probing depth reduction achieved following root planing and tetracycline hydrochloride therapy was maintained during this review period.     

盐酸小檗碱对大鼠牙周组织中白细胞介素-1β和肿瘤坏死因子-α表达的影响

目的探讨盐酸小檗碱对大鼠实验性牙周炎模型牙周组织中白细胞介素- 1β（IL- 1β）和肿瘤坏死因子- α（TNF- α）表达的影响。方法在成功建立大鼠实验性牙周炎模型的基础上，实验动物在分别灌服盐酸小檗碱后第1、2、3、4周处死，取牙周组织标本作切片，行常规苏木精- 伊红染色，观察牙周组织病理变化状况，并采用免疫组织化学SABC法检测IL- 1β、TNF- α水平变化。结果牙周炎组牙周组织中IL- 1β、TNF- α表达明显高于正常组（P<0.05）；各时间段牙周炎治疗组牙周组织中IL- 1β、TNF- α表达明显低于牙周炎组（P<0.05），但牙周炎治疗组各时间段之间IL- 1β、TNF- α表达无显著差异。结论大鼠实验性牙周炎模型牙周组织中TNF- α、IL- 1β表达水平较正常对照组明显升高，应用盐酸小檗碱能抑制实验性牙周炎模型牙周组织中TNF- α、IL- 1β的表达。     

Tetracycline inhibits Porphyromonas gingivalis lipopolysaccharide-induced lesions in vivo and TNFα processing in vitro

Lipopolysaccharides (LPS) are considered one of the more important virulence factors related to the pathogenesis of periodontal diseases. Based on tetracycline (TTC) ability to bind divalent metal ions, the present study was designed to examine the effect of TTC on P. gingivalis LPS-induced lesions in vivo and on LPS-induced TNFα production in vitro . Subcutaneous injection of 50-100 μg of P. gingivalis LPS into BALB/C mice induced a visible lesion within 24 h with evident tissue necrosis. Daily systemic administration of TTC for the first 4 d following LPS challenge reduced the size of the lesion, and total inhibition of lesion formation was observed in 75-100% of the treated mice. A non-related broad spectrum antibiotic, ampicillin, or the IL-1 inhibitor ML-20, had no effect on the lesion size. In order to explore some aspects of the mechanism involved, we tested the effect of TTC on LPS-induced TNFα secretion by human monocytes in vitro . TTC (1 mM) was found to block LPS-stimulated TNFα secretion. Western blotting of monocyte cytoplasmic membranes for membrane-bound TNFα show that TTC causes the retention of membrane-associated TNFα on monocyte membranes, thereby preventing the release of TNFα into the culture media. The results suggest the TTC is an effective in vivo therapy for preventing P. gingivalis LPS-induced subcutaneous lesion formation in the murine model. The mechanism of TTC treatment probably involves blocking the activity of metal] oprotemases. including TNFY processing enzyme, thereby preventing LPS-induced tissue destruction.     

双抗胶原膜的临床抗菌抗降解观察

目的：评估自行研制用于引导牙周组织再生（ＧＴＲ）的双抗胶原膜（ＢＡＣＭ）在临床应用中实际抗菌能力和抗酶解性能。方法：对１２例牙周炎患者行体内药物释放试验，以高效液相色谱测其龈沟液四环素含量；应用扫描电镜观察ＧＴＲ术后１周取出的ＢＡＣＭ膜上的细菌附着情况。结果：牙周袋内放置四环素１５０μｇ，１周后龈沟液中药物浓度为２０．７８μｇ／ｍｌ，扫描电镜观察胶原膜纤维结构完好无损，ＢＡＣＭ上细菌数明显少于对照膜（ＧＬＣＭ）。结论：临床评估ＢＡＣＭ能显著减少细菌对胶原膜的附着，并具有一定抗胶原酶的性能。     

脑脉利颗粒中芍药苷，益母草碱，黄芪甲苷及盐酸水苏碱含量测定

目的：建立脑脉利颗粒中芍药苷,益母草碱,黄芪甲苷及盐酸水苏碱的含量测定方法。方法：采用甲醇、酸水等不同的溶剂提取,并采用高效液相色谱法,液质联用法等灵敏、专属的色谱方法进行含量测定。结果：每10g脑脉利颗粒中含有芍药苷 42.41 mg,益母草碱 1.73mg,黄芪甲苷 0.10 mg,盐酸水苏碱 37.98mg。结论：制剂中其他组分与所测定的各组分分离良好,不干扰测定,可用于脑脉利颗粒中芍药苷,益母草碱,黄芪甲苷及盐酸水苏碱的含量测定。     

T型关联度分析法优化益母草中盐酸水苏碱的提取工艺

目的优化盐酸水苏碱提取工艺。方法用T型关联度分析法对盐酸水苏碱提取工艺进行了研究。结果根据益母草提取物中盐酸水苏碱含量的关联度结果,各因素相关度大小为：X1〉X5〉X4〉X3〉X2,最佳工艺为12倍量水（V/W）提取2 h,90%乙醇用量6倍量,调pH 4。结论将T型关联度分析法用于益母草水苏碱提取工艺为工业化生产提供实验依据。