BMP2 gene delivery to bone mesenchymal stem cell by chitosan-g-PEI nonviral vector

published_or_final_versio

Enhanced gene delivery by chitosan-disulfide-conjugated LMW-PEI for facilitating osteogenic differentiation

postprin

Bone turnover and articular cartilage differences localized to subchondral cysts in knees with advanced osteoarthritis

Objective: To investigate changes in bone structure, turnover, and articular cartilage localized in subchondral bone cyst (SBC) regions associated with knee osteoarthritis (OA). Methods: Tibial plateaus (n ¼ 97) were collected from knee OA patients during total knee arthroplasty (TKA). SBCs were identified using micro-computed tomography, and the specimens were divided into non-cyst (n ¼ 25) and bone cyst (n ¼ 72) groups. Microstructure of subchondral bone was assessed using bone volume fraction (BV/TV), trabecular number (Tb.N), structure model index (SMI) and bone mineral density (BMD). In bone cyst group, the cyst subregion, which contained at least one cyst, and the pericyst subregion, which contained no cysts, were further selected for microstructure analysis. Articular cartilage damage was estimated using the Osteoarthritis Research Society International (OARSI) score. The numbers of TRAPþ osteoclasts, Osterixþ osteoprogenitors, Osteocalcinþ osteoblasts and expression of SOX9 were evaluated by immunohistochemistry. Results: Bone cyst group presented higher BV/TV, Tb.N and SMI at subchondral bone than non-cyst group. Furthermore, cyst subregion displayed increased BV/TV and Tb.N but lower BMD and SMI than peri-cyst subregion. Histology revealed a higher OARSI score in bone cyst group. SBC exhibited a weak relationship with BV/TV, etc. The numbers of TRAPþ osteoclasts, Osterixþ osteoprogenitors, Osteocalcinþ osteoblasts and expression of SOX9, were higher in bone cyst group. Conclusion: SBCs within knee OA are characterized by focally increased bone turnover, altered bone structure and more severe articular cartilage damage. The increased bone turnover possibly contributes to altered bone structure localized in SBC areas, and thus aggravates articular cartilage degeneration. © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.postprin

聚甲基丙烯酸甲酯強化和修復椎弓根螺釘的生物力學研究

Objective To evaluate pedicle screw fixation strength following augmentation and restoration with polymethylmethacrylate (PMMA). Methods Compact CD (CCD) screws of 6.0 mm diameter was implanted into the pedicle unilaterally. And a pilot hole was created using 3.5 mm drill contralaterally on eight fresh human lower lumbar vertebrae (L 3-5).Neither the screws nor the drillings penetrated the anterior cortex of the vertebral bodies. The screws were pulled out from the vertebrae at 5 mm/min. The screw track and the pilot hole were filled with 3-5 ml of PMMA. Then, the screws were implanted bilaterally, and the PMMA was allowed to harden for 1 hour. Morphology of PMMA around the screws was observed by section of the vertebrae along the screw. Results Pullout force of pedicle screw fixation in normal vertebrae was (825.5±254.7) N and (1 711.1±488.8)N following augmentation with PMMA. Restoration of a pullout pedicle screw fixation with PMMA was able to salvage pullout force to (1 832.4±497.4) N. The pullout forces following augmentation and restoration were significantly greater than that in normal vertebrae. Morphology of PMMA around the screws was related to the viscosity of PMMA during injection. No PMMA was found in vertebral canal or surface of pedicle. Conclusion Augmentation and restoration with PMMA offered a significantly increase of strength for pedicle screw fixation, and could be used clinically in case of failure of pedicle screw fixation. 目的 評價聚甲基丙烯酸甲酯(polymethylmethacrylate ,PMMA)強化和修復椎弓根螺釘固定的生物力學效果。方法8具成人新鮮腰椎骨L3～5,隨機選擇一側椎弓根放置直徑為6.0mm的CCD(compactCD)椎弓根螺釘 ,另一側以直徑為3.5mm的鉆頭導孔 ,均不穿透椎體前皮質。在材料試驗機上進行椎弓根螺釘拔出實驗 ,拔出速率為5mm/min。然后沿椎弓根孔道注入PMMA粉和水按體積1∶2混合的PMMA強化修復材料3～5ml,雙側椎弓根分別使用與前相同的CCD椎弓根螺釘 ,室溫下1h后再行前述拔出實驗。沿椎弓根螺釘長度方向鋸開標本 ,觀察PMMA在螺釘孔道中的分布范圍。結果CCD椎弓根螺釘在正常椎弓根內的最大拔出力為 (825.5±254.7)N ;在經強化后的正常椎弓根內和在修復失效的椎弓根內 ,CCD椎弓根螺釘最大拔出力分別為 (1711.1±488.8)N和 (1832.4±497.4)N ,高于正常椎弓根螺釘的最大拔出力 ,差異有顯著性意義(P<0.01)。PMMA在螺釘周圍的分布與其注入時的粘稠度有關 ,未見椎管內或椎弓根外有PMMA分布。結論沿椎弓根孔道注入PMMA可顯著增加椎弓根螺釘的拔出力 ,適用于螺釘松動和拔出的修復固

Arc Discharge Synthesis and Photoluminescence of 3D Feather-like AlN Nanostructures

A complex three-dimensional (3D) feather-like AlN nanostructure was synthesized by a direct reaction of high-purity Al granules with nitrogen using an arc discharge method. By adjusting the discharge time, a coral-like nanostructure, which evolved from the feather-like nanostructure, has also been observed. The novel 3D feather-like AlN nanostructure has a hierarchical dendritic structure, which means that the angle between the trunk stem and its branch is always about 30° in any part of the structure. The fine branches on the surface of the feather-like nanostructure have shown a uniform fish scale shape, which are about 100 nm long, 10 nm thick and several tens of nanometers in width. An alternate growth model has been proposed to explain the novel nanostructure. The spectrum of the feather-like products shows a strong blue emission band centered at 438 nm (2.84 eV), which indicates their potential application as blue light-emitting diodes

Introduction: Ideology, propaganda, and political discourse in the Xi Jinping era

The ideology, propaganda, and political discourse of the Communist Party of China (CPC) have continued to function as key elements of the political system of the People’s Republic of China (PRC) in the post-Maoist period since 1978. In the first term of the Xi Jinping leadership (2012–2017), the CPC, for instance, elaborated on its guiding ideological concepts, devised inventive ideational framings of phenomena usually perceived as tangible (such as the BNew Normal^), engaged in complex intellectual debates on crucial topics (such as Beco-civilization^), intensified and diversified its argumentation patterns and discursive strategies, and consolidated ideational governance over some citizens’ individual values, beliefs, and loyalties. Furthermore, it is often no longer possible to differentiate between the CPC’s internal and external propaganda, as seemingly exclusively domestic ideational and discursive issues increasingly correlate with international phenomena. However, the trends in the Xi era do not present paradigmatic shifts, but rather an overall reassertion-cuminnovation of previous Maoist and post-Maoist uses of ideology, propaganda, and political discourse, primarily aiming at strengthening one-party rule

Analysis of MicroRNA Expression in Embryonic Developmental Toxicity Induced by MC-RR

As cynobacterial blooms frequently occur in fresh waters throughout the world, microcystins (MCs) have caused serious damage to both wildlife and human health. MCs are known to have developmental toxicity, however, the possible molecular mechanism is largely unknown. This is the first toxicological study to integrate post-transcriptomic, proteomic and bioinformatics analysis to explore molecular mechanisms for developmental toxicity of MCs in zebrafish. After being microinjected directly into embryos, MC-RR dose-dependently decreased survival rates and increased malformation rates of embryos, causing various embryo abnormalities including loss of vascular integrity and hemorrhage. Expressions of 31 microRNAs (miRNAs) and 78 proteins were significantly affected at 72 hours post-fertilisation (hpf). Expressions of miR-430 and miR-125 families were also significantly changed. The altered expressions of miR-31 and miR-126 were likely responsible for the loss of vascular integrity. MC-RR significantly reduced the expressions of a number of proteins involved in energy metabolism, cell division, protein synthesis, cytoskeleton maintenance, response to stress and DNA replication. Bioinformatics analysis shows that several aberrantly expressed miRNAs and proteins (involved in various molecular pathways) were predicted to be potential MC-responsive miRNA-target pairs, and that their aberrant expressions should be the possible molecular mechanisms for the various developmental defects caused by MC-RR

Treatable Traits in Elderly Asthmatics from the Australasian Severe Asthma Network: A Prospective Cohort Study.

BACKGROUND: Data on treatable traits (TTs) in different populations are limited. OBJECTIVE: To assess TTs in elderly patients with asthma and compare them to younger patients, to evaluate the association of TTs with future exacerbations, and to develop an exacerbation prediction model. METHODS: We consecutively recruited 521 participants at West China Hospital, Sichuan University based on the Australasian Severe Asthma Network, classified as elderly (n = 62) and nonelderly (n = 459). Participants underwent a multidimensional assessment to characterize the TTs and were then followed up for 12 months. TTs and their relationship with future exacerbations were described. Based on the TTs and asthma control levels, an exacerbation prediction model was developed, and the overall performance was externally validated in an independent cohort. RESULTS: A total of 38 TTs were assessed. Elderly patients with asthma had more chronic metabolic diseases, fixed airflow limitation, emphysema, and neutrophilic inflammation, whereas nonelderly patients with asthma exhibited more allergic characteristics and psychiatric diseases. Nine traits were associated with increased future exacerbations, of which exacerbation prone, upper respiratory infection-induced asthma attack, cardiovascular disease, diabetes, and depression were the strongest. A model including exacerbation prone, psychiatric disease, cardiovascular disease, upper respiratory infection-induced asthma attack, noneosinophilic inflammation, cachexia, food allergy, and asthma control was developed to predict exacerbation risk and showed good performance. CONCLUSIONS: TTs can be systematically assessed in elderly patients with asthma, some of which are associated with future exacerbations, proving their clinical utility of evaluating them. A model based on TTs can be used to predict exacerbation risk in people with asthma

The Endogenous Th17 Response in NO<inf>2</inf>-Promoted Allergic Airway Disease Is Dispensable for Airway Hyperresponsiveness and Distinct from Th17 Adoptive Transfer

Severe, glucocorticoid-resistant asthma comprises 5-7% of patients with asthma. IL-17 is a biomarker of severe asthma, and the adoptive transfer of Th17 cells in mice is sufficient to induce glucocorticoid-resistant allergic airway disease. Nitrogen dioxide (NO2) is an environmental toxin that correlates with asthma severity, exacerbation, and risk of adverse outcomes. Mice that are allergically sensitized to the antigen ovalbumin by exposure to NO2 exhibit a mixed Th2/Th17 adaptive immune response and eosinophil and neutrophil recruitment to the airway following antigen challenge, a phenotype reminiscent of severe clinical asthma. Because IL-1 receptor (IL-1R) signaling is critical in the generation of the Th17 response in vivo, we hypothesized that the IL-1R/Th17 axis contributes to pulmonary inflammation and airway hyperresponsiveness (AHR) in NO2-promoted allergic airway disease and manifests in glucocorticoid-resistant cytokine production. IL-17A neutralization at the time of antigen challenge or genetic deficiency in IL-1R resulted in decreased neutrophil recruitment to the airway following antigen challenge but did not protect against the development of AHR. Instead, IL-1R-/- mice developed exacerbated AHR compared to WT mice. Lung cells from NO2-allergically inflamed mice that were treated in vitro with dexamethasone (Dex) during antigen restimulation exhibited reduced Th17 cytokine production, whereas Th17 cytokine production by lung cells from recipient mice of in vitro Th17-polarized OTII T-cells was resistant to Dex. These results demonstrate that the IL-1R/Th17 axis does not contribute to AHR development in NO2-promoted allergic airway disease, that Th17 adoptive transfer does not necessarily reflect an endogenously-generated Th17 response, and that functions of Th17 responses are contingent on the experimental conditions in which they are generated. © 2013 Martin et al