海洋微生物活性代谢产物的研究进展

研究海洋微生物活性物质 ,不但能发现结构新颖的化合物 ,而且能寻找到新的强效抗生素和抗病毒等活性的新药以及其它有用物质 ,这一新兴领域的研究在理论上和维护人类健康方面都有重大意义。本文综述了 2 0 0 0年以来对海洋微生物 (包括海洋细菌、蓝细菌、放线菌、真菌 )活性代谢产物的研究进展 ,共引用文献 6 9篇 ,包括 12 9个活性代谢产物。重点描述了这些化合物的相关生理活性 ,产生它们的微生物及微生物的采集地。     

区域注射磷—32玻璃微球对裸鼠移植性人肝细胞癌的形态学影响

目的：研究－３２玻璃微球（３２Ｐ－ＧＭＳ）区域注射对裸鼠移植性人肝细胞癌的形态学影响及其意义。方法：应用光镜、免疫组织化学及电镜观察对照组及治疗组的肿瘤组织学和超微结构特征。结果：对照组中，瘤体长径约３ｃｍ，瘤细胞排列紧密，呈小梁状，富于血窦，约５％瘤细胞坏死。治疗组中，瘤体长径为０．４～２ｃｍ，其中少部分瘤体边缘细胞排列紧密，大部分瘤细胞排列松散，呈网状或假腺样且被纤维血管束分割成巢。４０％～８０％的瘤细胞呈凝固性坏死。７５％以上排列紧密的瘤细胞ＰＣＮＡ阳性，而排列松散的ＰＣＮＡ阳性瘤细胞不足２５％。松散排列的瘤细胞较紧密排列的瘤细胞，桥粒显著减少、细胞变性坏死增多。结论：本研究提示局部内放射３２Ｐ－ＧＭＳ明显具有杀伤癌细胞和抑制肿瘤生长的作用。这为３２Ｐ－ＧＭＳ对肝癌治疗的实验研究和临床应用提供形态学依据。     

药品包装材料对液体药剂质量的影响

目的:探讨药品包装材料与用药安全的关系。方法:参考有关文献并结合我国实际情况进行分析。结果:药品包装材料质量对人体能产生一定的危害,对药品质量也产生一定的影响。结论:应按药品的理化性质选用合适的药品包装材料,药品包装材料生产企业也要按专业标准化生产药品包装材料,以适应各种药品包装的需求。     

B超在眼后段异物测量中的准确性分析

目的：评估B超在不同性质眼后段异物大小测量中的准确性。

方法：回顾性分析2016-01/12在我院被诊断为眼后段异物的患者13例13眼。异物在取出后用直尺测量实际大小,并同术前B超所测数值进行比较,同时计算相关系数(B超测量值/实际大小)。为了排除手术操作损伤异物对真实大小测量的影响,选定长度为5mm的不同材质物体(分别为金属、玻璃和木质)放入直径约20～30mm的水囊中模拟眼内异物,同样进行以上的测量,测量重复4次。

结果：选取13眼内异物均经玻璃体手术完整取出,其中金属磁性异物12眼,玻璃异物1眼。12个金属异物术前B超所测长轴和实际长度的平均值分别为3.65±1.30和2.45±0.94mm,所有测量值均大于实际值(P=0.016)。相关系数的平均值为1.49。体外实验中,金属、玻璃和木质三种不同性质异物B超的平均测量值分别为6.76±0.15、6.55±0.04和6.02±0.07mm,相关系数分别为1.35、1.31和1.20。

结论：B超用于眼后段异物测量时,其所测量值会大于真实大小,尤其是对于金属和玻璃异物。因此在术中制作异物取出切口时需要进行考虑。     

Engineering strategies to control vascular endothelial growth factor stability and levels in a collagen matrix for angiogenesis: The role of heparin sodium salt and the PLGA-based microsphere approach

New vessel formation is the result of the complex orchestration of various elements, such as cells, signalling molecules and extracellular matrix (ECM). In order to establish the suitable conditions for an effective cell response, the influence of vascular endothelial growth factor (VEGF) complexation with heparin sodium salt (Hp) on its pro-angiogenic activity has been evaluated by an in vitro capillary-like tube formation assay. VEGF with or without Hp was embedded into collagen gels, and the activated matrices were characterized in terms of VEGF activity and release kinetics. Taking into account the crucial role of Hp in VEGF stability and activity, VEGF/Hp complex was then encapsulated into microspheres based on poly(lactide-co-glycolide) (PLGA), and microsphere properties, VEGF/Hp release kinetics and VEGF in vitro activity over time were evaluated. Integrated microsphere/collagen matrices were developed in order to provide a continuous release of active VEGF/Hp inside the matrix but also a VEGF gradient at the boundary, which is an essential condition for endothelial cell attraction and scaffold invasion. The results confirmed a strong influence of Hp on VEGF configuration and, consequently, on its activity, while the encapsulation of VEGF/Hp complex in PLGA-microspheres guaranteed a sustained release of active VEGF for more than 30 days. This paper confirms the importance of VEGF stability and signal presentation to cells for an effective proangiogenic activity and highlights how the combination of two stabilizing approaches, namely VEGF/Hp complexation and entrapment within PLGA-based microspheres, may be a very effective strategy to achieve this goal.     

Fluoride bioactive glass paste improves bond durability and remineralizes tooth structure prior to adhesive restoration

ObjectiveThe current study aimed at examining a fluoride containing bioactive glass (BiominF®) paste as a temporary filling material capable of remineralizing the demineralized enamel or dentin, and its ability to decrease a simulated dentinal fluids pressure on the resin/dentin interface, without affecting the shear bond strength of a universal bonding agent to enamel and dentin.Methods60 premolars were utilized for the acid resistance, trans-microradiography (TMR) and shear bond strength (SBS) experiments. Enamel and dentin discs were demineralized for 4 days to create a subsurface demineralized zone followed by applying BiominF® paste, 1.23% acidulated phosphate fluoride, or a temporary filling material for 24 h.30 extracted human non-carious third molars were utilized for the pulpal pressure experiment in which direct communication to the pulp chamber was created by cutting at a level approximately 1 mm below the cemento-enamel junction while the coronal enamel was ground to expose mid coronal dentin. The dentin surface was exposed to a simulated pulpal pressure. The dentin surfaces had BiominF® paste, an oxalate desensitizing agent, or temporary filling material followed by application of a universal adhesive system.ResultsOne way ANOVA showed that BiominF® paste remineralized effectively the demineralized enamel or dentin, did not affect the bond strength of the enamel and dentin surfaces to the tested adhesive system p < 0.05, and improved the acid resistance of the demineralized enamel and dentin against a secondary erosive challenge. Moreover, BiominF® paste decreased the nanoleakage expression in the dentin/adhesive interface exposed to a simulated pulpal pressure.SignificanceBiominF® paste may serve as a temporary filling material that may improve the longevity of adhesive restorations and help to conserve tooth structures by preserving the demineralized enamel and dentin form cutting during cavity preparation.     

Reinforcement in removable prosthodontics: a literature review

Removable prosthodontics are often associated with mechanical troubles in daily use, such as fracture or deformation. These troubles render prostheses unusable and reduce wearers’ QOL. Various reinforcements are used to prevent such problems, but consensus on reinforcement has not been reached. This review aimed to summarise the effects of reinforcement and to propose favourable reinforcement based on material, design and position in the prostheses. Initially, 139 articles were selected by electronic and manual searches. After exclusion of 99 articles based on the exclusion criteria, 40 articles were finally included in the review. Electronic searches were performed for articles published from 2005 to 2015 in PubMed, EMBASE, MEDLINE and Cochrane Library, and manual searches were performed in 10 journals relevant to the topic of removable prosthodontics. For in vitro studies, certain dental alloys and fibres were mainly used. Their forms were different, including complicated forms in dental alloys and various forms in fibres. The materials were examined for mechanical properties like fracture strength, flexural strength and elastic modulus and compared with one another or without reinforcement. There were a few clinical studies and one longitudinal study. Cast metal reinforcement seemed to be most favourable in terms of fracture toughness and stiffness. The most favourable forms differed depending on the prostheses, but placement around thin and deformable areas was effective. However, randomised or longitudinal clinical reports and comparative clinical studies on the use of reinforcement were still lacking and such studies are necessary in the future.     

Characterization and induction of cementoblast cell proliferation by bioactive glass nanoparticles

Cementum is a mineralized tissue that lines the surface of the tooth root enabling attachment of the periodontal ligament to the root and surrounding alveolar bone. Studies examining the mechanisms involved in the formation of root cementum have been hindered by an inability to isolate and culture the cells required for cementum production (cementoblasts). This study isolated and characterized cementoblast cells derived from rat molar periodontal ligament. It was observed that the isolated cells expressed F‐Spondin, a cementoblast marker, while F‐Spondin expression was not observed in the cells of other tissues such as gingival fibroblasts and osteoblasts. As expected, the isolated cementoblast cells also expressed osteocalcin (OC), bone sialoprotein (BSP), alkaline phosphatase (ALP), and type I collagen, demonstrating the presence of mineralized tissues genes in cementoblast cells. These cells showed high ALP activity and calcified nodule formation in vitro. Since cementogenesis could be a critical event for regeneration of periodontal tissues, this study investigated whether bioactive glass particles could affect the proliferation of cementoblasts since they are known to enhance osteoblast proliferation. It was found that the ionic products from bioactive glass nanoparticles increased cementoblast viability, mitochondrial activity, and induced cell proliferation. Together, these results show the characterization of cementoblast cells from rat molar periodontal ligament. Additionally, it was shown that bioactive glass nanoparticles induced cementoblast to proliferate, indicating that they could be a potential material for use in cement regeneration through tissue engineering. Copyright © 2011 John Wiley & Sons, Ltd.