Cell uptake and oral absorption of titanium dioxide nanoparticles

Large efforts are invested on the development of in vitro tests to evaluate nanomaterial (NM) toxicity. In order to assess the relevance of the adverse effects identified in in vitro toxicity tests a thorough understanding of the biokinetics of NMs is critical. We used different in vitro and in vivo test methods to evaluate cell uptake and oral absorption of titanium dioxide nanoparticles (TiO₂ NPs). These NPs were readily uptaken by A549 cells (carcinomic human alveolar basal epithelial cells) in vitro. Such rapid uptake contrasted with a very low oral absorption in a differentiated Caco-2 monolayer system (human epithelial colorectal adenocarcinoma cells) and after oral gavage administration to rats. In this oral study, no significant increase in the levels of titanium was recorded by ICP-MS in any of the tissues evaluated (including among other: small intestine, Peyer's patches, mesenteric lymph nodes, liver, and spleen). No NPs were observed by TEM in sections of the small intestine, except for several particles in the cytoplasm of a cell from a Peyer's Patch area. The observation of NPs in Peyer's Patch suggests that the Caco-2 monolayer system is likely to underestimate the potential for oral absorption of NPs and that the model could be improved by including M-cells in co-culture.     

食管缺损经肺组织瓣和金属支架重建后黏膜爬行的光镜和电镜观察

 目的 探讨肺组织瓣修复食管侧壁缺损内衬金属支架的方法进行食管重建的可行性。 方法 选取成年犬12条,切除中段食管,选用右中叶肺组织作为替代物,将金属支架放置于缺损处食管内,用游离的肺组织瓣修补食管缺损。术后行钡餐透视检查及病理学检查,通过光镜和电镜观察黏膜的爬行过程,爬行的新生上皮的超微结构。结果 新生食管复层上皮与肺组织瓣连接紧密,愈合良好。但术后18周腺体和平滑肌的再生均不明显。结论 肺组织瓣内衬金属支架重建食管为食管替代提供了一种新的尝试，作为支撑物其远期效果有待进一步探讨。     

医源性十二指肠穿孔钛夹封闭治疗的护理

目的 探讨金属钛夹在内镜下封闭治疗医源性十二指肠急性穿孔中的应用及护理配合.方法 收集2例经自然腔道的内镜手术导致十二指肠急性穿孔者,进行内镜下钛夹封闭治疗.结果 2例患者均在内镜直视下予多枚金属钛夹封闭创面,术后予心电监护、禁食、胃肠减压、抗生素预防感染以及营养支持治疗,术后无出血、再穿孔、腹腔脓肿等并发症发生,均恢复良好.结论 早期内镜下钛夹封闭是治疗内镜诊治出现的医源性穿孔的有效方法,充分的术前准备、熟练的术中医护配合、精心的术后护理是成功治疗的重要保证.     

Could self-locking stand-alone cage reduce adjacent-level ossification development after aneterior cervical discectomy and fusion?

Numerous studies have shown that cervical arthrodesis is associated with the adjacent-segment pathology (ASP), such as adjacent-level ossification development (ALOD). However, it still remains largely unclear whether the self-locking stand-alone implant system can reduce the incidence of ALOD. In the present study, we prospectively recruited 120 patients with cervical degenerative disc disease (CDDD) who were treated by anterior cervical discectomy and fusion (ACDF). These patients were randomly and evenly divided into the ROI-C group and plate group. Clinical and radiologic follow-up was performed at 3, 6, 12, 24 and 36 months after surgery. Clinical evaluation included preoperative and postoperative assessments of Japanese Orthopaedic Association (JOA) score and Neck Disability Index (NDI) score. The presence and severity of ALOD, as well as the C2-7 Cobb angle, were assessed on the lateral cervical films during follow-up. There were no significant differences in JOA and NDI scores at each time point during the follow-up period between the two groups. ALOD occurred in 8.8% of 58 patients and 6.7% of 104 levels in the cage group. Moreover, ALOD occurred in 20.1% of 57 patients and 17.8% of 101 levels in the plate group. The ALOD was more serious in the plate group compared with the cage group. The C2-7 Cobb angle was significantly improved compared with that before the operation and could be maintained during the follow-up in both groups. The self-locking stand-alone cage was efficacious for ACDF, and it could reduce the incidence of ALOD compared with anterior plate and cage.     

Fe-Ga合金磁特性测试装置的设计与实验

设计了一种新型Fe-Ga合金磁特性测试装置。建立了该测试装置磁路部分三维有限元磁场分析模型，在该模型基础上通过调整结构和元件尺寸优化了磁路结构，并制作了样机。搭建了磁特性测试装置的实验平台，进行了Fe-Ga合金磁特性测试。实验结果表明，该装置可对Fe-Ga合金磁致伸缩棒材磁致伸缩效应和逆磁致伸缩效应进行静态、准静态和动态测量，测量结果与国外报道的结果一致。设计的磁特性测试装置具有稳定可靠、精度高、操作简单、自动记录等优点。该装置还适用于Fe-Ni、Fe-Co等饱和磁场低的磁致伸缩材料的磁特性测量。     

Easy anchoring and smaller skin incision procedure for neuronavigation-based frameless stereoelectroencephalography

Epilepsy surgery uses both depth electrodes (DEs) and subdural electrodes (SE). DEs have mainly been developed and used in Europe. As we are able to use the DEs safely due to the current advanced level of technology, use of DEs has been increasing rapidly over the last decade. Unlike placement of SEs, which simply requires craniotomy, DE placement generally requires stereotactic techniques such as frame-based stereotactic or robotic arm-based methods. However, such methods are not always available at every epilepsy center. We therefore invented guide pipes for accurate DE placement. With this guide pipe and neuronavigation-based (NB) DE placement system, we are able to place DEs accurately. However, the disadvantages of our original procedure were a relatively large skin incision and the difficulty in anchoring DEs. The purpose of this technical note is to introduce a method to perform NB DE placement with a smaller skin incision and simple anchoring procedure. As we could make the skin incision smaller and achieved easier anchoring of DEs using a titanium plate, we hope this procedure will help facilities to perform DE placement with neuronavigation systems.     

Effect of soft tissue thickness over the posterior border of the vertebral body and disc space on cage placement during posterior lumbar interbody fusion: A cadaveric study

In the present study, we investigated whether there is a difference between visual depth (VD) and radiological image depth (RD) of cages (i.e., structural interbody support devices) placed in disc spaces during posterior lumbar interbody fusion and whether soft tissues covering the posterior border of the vertebral body and associated disc space are the cause of any observed differences. Using digital calipers, cages were inserted at a depth of 5 mm from the soft tissues covering the posterior border of the vertebral body and disc space under direct vision; this depth was defined as VD. After insertion, RD was measured in triplicate. The reliability of RD measurements was evaluated using an intraclass coefficient test. To identify the cause of differences between VD and RD, the thicknesses of soft tissues were measured microscopically. A total of 40 lumbar intervertebral disc spaces with cages were evaluated. The mean RD of cages was 3.12 mm, while the mean difference between the VD and RD of cages (DVRD) was 1.91 mm. On histological examination, the mean thickness of the soft tissue was 2.02 mm. Comparative analysis between histological values and DVRD showed no statistical difference (P = 1.14, 1.55, 0.06). There was a significant difference between VD and RD during cage placement, and soft tissue structure appeared to be responsible for the DVRD of inserted cages. Therefore, cages should be inserted deeper to account for differences between visual and radiological image depths. Clin. Anat. 25:1066–1073, 2012. © 2012 Wiley Periodicals, Inc.     

Effect of Al–5Ti–C Master Alloy on the Microstructure and Mechanical Properties of Hypereutectic Al–20%Si Alloy

Al–5Ti–C master alloy was prepared and used to modify hypereutectic Al–20%Si alloy. The microstructure evolution and mechanical properties of hypereutectic Al–20%Si alloy with Al–5Ti–C master alloy additions (0, 0.4, 0.6, 1.0, 1.6 and 2.0 wt%) were investigated. The results show that, Al–5Ti–C master alloy (0.6 wt%, 10 min) can significantly refine both eutectic and primary Si of hypereutectic Al–20%Si alloy. The morphology of the primary Si crystals was significantly refined from a coarse polygonal and star-like shape to a fine polyhedral shape and the grain size of the primary Si was refined from roughly 90–120 μm to 20–50 μm. The eutectic Si phases were modified from a coarse platelet-like/needle-like structure to a fine fibrous structure with discrete particles. The Al–5Ti–C master alloy (0.6 wt%, 30 min) still has a good refinement effect. The ultimate tensile strength (UTS), elongation (El) and Brinell hardness (HB) of Al–20%Si alloy modified by the Al–5Ti–C master alloy (0.6 wt%, 10 min) increased by roughly 65%, 70% and 51%, respectively, due to decreasing the size and changing the morphology on the primary and eutectic Si crystals. The change in mechanical properties corresponds to evolution of the microstructure.