Evaluation of three-dimensional biofilms on antibacterial bonding agents containing novel quaternary ammonium methacrylates

Antibacterial adhesives are promising to inhibit biofilms and secondary caries. The objectives of this study were to synthesize and incorporate quaternary ammonium methacrylates into adhesives, and investigate the alkyl chain length effects on three-dimensional biofilms adherent on adhesives for the first time. Six quaternary ammonium methacrylates with chain lengths of 3, 6, 9, 12, 16 and 18 were synthesized and incorporated into Scotchbond Multi-Purpose. Streptococcus mutans bacteria were cultured on resin to form biofilms. Confocal laser scanning microscopy was used to measure biofilm thickness, live/dead volumes and live-bacteria percentage vs. distance from resin surface. Biofilm thickness was the greatest for Scotchbond control; it decreased with increasing chain length, reaching a minimum at chain length 16. Live-biofilm volume had a similar trend. Dead-biofilm volume increased with increasing chain length. The adhesive with chain length 9 had 37% live bacteria near resin surface, but close to 100% live bacteria in the biofilm top section. For chain length 16, there were nearly 0% live bacteria throughout the three-dimensional biofilm. In conclusion, strong antibacterial activity was achieved by adding quaternary ammonium into adhesive, with biofilm thickness and live-biofilm volume decreasing as chain length was increased from 3 to 16. Antibacterial adhesives typically only inhibited bacteria close to its surface; however, adhesive with chain length 16 had mostly dead bacteria in the entire three-dimensional biofilm. Antibacterial adhesive with chain length 16 is promising to inhibit biofilms at the margins and combat secondary caries.     

高度近视眼后房型ICL植入术后波前像差的改变

目的:观察高度近视眼有晶状体眼后房型人工晶状体植入后全眼及眼内波前像差的变化。方法:选择行有晶状体眼人工晶状体(implantable collamer lens,ICL)植入术的高度近视眼患者25例50眼,用尼德克波前像差仪测量患者6mm瞳孔区域内术前和术后1mo的波前像差值,对其进行配对t检验。结果:ICL植入眼术后1mo全眼总体波前像差(OPDTotal)、眼内总体波前像差(Internal Total)较术前明显下降(P<0.05)。全眼总体高阶波前像差(OPD High)、全眼总体球面像差(OPDT.SPH)、全眼总体彗差(OPDT.Coma)、全眼总体三叶草(OPDT.Trefoil)、眼内总体彗差(Internal T.Coma)较术前有不同程度升高,具有统计学意义(P<0.05)。角膜总体波前像差(C-Total)、角膜总体高阶波前像差(C-High)、角膜球差(C-T.Sph)、角膜彗差(C-T.Coma)、角膜四叶草(C-T.4Foil)较术前有不同程度升高,角膜三叶草(C-T.Trefoil)较术前明显下降,但差异均无统计学意义。结论:有晶状体眼后房型人工晶状体植入术虽然显著降低了高度近视眼的总体波前像差,但术眼球面像差、彗差、三叶草等高阶波前像差有不同程度增加。     

微结构芯片对石墨粉吸附及3种口腔微生物黏附行为的影响

目的 通过制备精确控制微结构的材料样品,比较不同尺寸无生命物质的吸附行为及不同尺寸微生物的黏附行为,探讨微结构影响微生物黏附增殖的机制.方法 聚二甲基硅氧烷(PDMS)翻制羟磷灰石(HA)芯片上的23个微结构,并分别与不同尺寸的石墨粉和不同尺寸的口腔微生物共培养,观察并比较微结构大小及形状对石墨粉吸附和微生物黏附的影响...     

口腔转化医学

随着科学技术手段的飞速发展,大量累计的基础科研成果迫切需要转化为临床应用,这催生了新的医学研究领域--转化医学.转化医学是指对实验所得的新型检测手段或治疗方法 在人体上进行可行性地验证及转化,同时其含义涵盖了以病患需求为中心的人口研究,并探索怎样将研究结果 有效地运用于公共卫生领域.转化医学是近年来最炙手可热的研究领域...     

+8伴JAK2突变的骨髓增生异常/骨髓增殖性疾病不能分类1例

本研究探讨1例骨髓增生异常/骨髓增殖性疾病不能分类(MDS/MPD-U)患者的临床特征、染色体核型与JAK2基因突变发生的关系。利用骨髓组织学活检、染色体核型分析技术、ARMS-PCR等方法,观察该MDS/MPD-U患者的临床特征、染色体核型、JAK2基因突变情况。结果表明,患者骨髓有典型的小巨核细胞、血小板增多、8号染色体三体异常、JAK2 V617F基因突变。结论:该患者符合MDS/MPD-U的诊断,伴有+8,JAK2 V617F基因突变,为进一步研究染色体核型异常与JAK2 V617F基因突变两种分子事件之间的相关性及对MDS/MPD-U预后的影响提供依据。     

Effects of 45S5 bioglass on surface properties of dental enamel subjected to 35%hydrogen peroxide

Tooth bleaching agents may weaken the tooth structure. Therefore, it is important to minimize any risks of tooth hard tissue damage caused by bleaching agents. The aim of this study was to evaluate the effects of applying 45S5 bioglass (BG) before, after, and during 35%hydrogen peroxide (HP) bleaching on whitening efficacy, physicochemical properties and microstructures of bovine enamel. Seventy-two bovine enamel blocks were prepared and randomly divided into six groups:distilled deionized water (DDW), BG, HP, BG before HP, BG after HP and BG during HP. Colorimetric and microhardness tests were performed before and after the treatment procedure. Representative specimens from each group were selected for morphology investigation after the final tests. A significant color change was observed in group HP, BG before HP, BG after HP and BG during HP. The microhardness loss was in the following order:group HP.BG before HP, BG after HP.BG during HP.DDW, BG. The most obvious morphological alteration of was observed on enamel surfaces in group HP, and a slight morphological alteration was also detected in group BG before HP and BG after HP. Our findings suggest that the combination use of BG and HP could not impede the tooth whitening efficacy. Using BG during HP brought better protective effect than pre/post-bleaching use of BG, as it could more effectively reduce the mineral loss as well as retain the surface integrity of enamel. BG may serve as a promising biomimetic adjunct for bleaching therapy to prevent/restore the enamel damage induced by bleaching agents.     

单纯腰椎平片漏诊完全型骶椎腰化2例报道

一般认为,单纯腰椎平片难以鉴别腰椎骶化(sacralization,SZ)与骶椎腰化(lumbarization,LZ),但不会漏诊腰骶移行椎(lumbosacral transitional vertebrae,LSTV).1984年Castellvi依据腰椎平片将LSTV分为Ⅳ类,现临床仍广泛采用~([1]).     

The microstructure of secondary lymphoid organs that support immune cell trafficking

Immune cell trafficking in the secondary lymphoid organs is crucial for an effective immune response. Recirculating T cells constantly patrol not only secondary lymphoid organs but also the whole peripheral organs. Thoracic duct lymphocytes represent an ideal cell source for analyzing T cell trafficking: high endothelial venules (HEVs) allow recirculating lymphocytes to transmigrate from the blood directly, and recirculating T cells form a cluster with dendritic cells (DCs) to survey antigen invasions even in a steady state. This cluster becomes an actual site for the antigen presentation when DCs have captured antigens. On activation, effector and memory T cells differentiate into several subsets that have different trafficking molecules and patterns. DCs also migrate actively in a manner depending upon their maturational stages. Danger signals induce the recruitment of several DC precursor subsets with different trafficking patterns and functions. In this review, we describe general and specialized structures of the secondary lymphoid organs for the trafficking of T cells and DCs by a multicolor immunoenzyme staining technique. The lymph nodes, spleen, and Peyer's patches of rats were selected as the major representatives. In vivo trafficking of subsets of T cells and DCs within these organs under steady or emergency states are shown and discussed, and unsolved questions and future prospects are also considered.