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Xiaohui Pan,1,* Haibo Li,1,* Jingxue Tan,1,* Xiaokun Weng,2 Li Zhou,1 Yiping Weng,1 Xiaojian Cao3 1Department of Orthopedics, The Affiliated Hospital of Nanjing Medical University, Changzhou No.2 People’s Hospital, Changzhou, Jiangsu 213003, People’s Republic of China; 2Department of Radiotherapy, The Affiliated Hospital of Nanjing Medical University, Changzhou No.2 People’s Hospital, Changzhou, Jiangsu 213003, People’s Republic of China; 3Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yiping Weng; Xiaojian Cao Email wyp2020cz@163.com; dr_cxj001@163.comBackground: MiR-1297 is reported to function as a tumor suppressor of various cancers. However, the role of miR-1297 in the development of osteosarcoma (OS) has not been elaborated. The purpose of this study was to investigate the functional effects of miR-1297 on OS progression and the underlying mechanism.Methods: The expression of protein and mRNA in OS cells was evaluated by Western blotting and quantitative real-time polymerase chain reaction. Cellular proliferation was investigated by cell counting kit-8, colony formation and apoptosis assays. Bioinformatics methods were used to predict target genes. The relationship between PFKFB2 and miR-1297 was demonstrated by dual-luciferase reporter assay. Metabolic changes in OS cells were monitored using an XF96 metabolic flux analyzer.Results: We found that miR-1297 was downregulated in OS and that lower expression of miR-1297 promoted proliferation and contributed to the Warburg effect in OS cells. Furthermore, we showed that silencing PFKFB2 inhibited proliferation and reduced aerobic glycolysis while overexpression of PFKFB2 reduced the anti-tumor function of miR-1297 in OS cells. Mechanistically, miR-1297 acted as a tumor suppressor in OS and reduced the expression of PFKFB2 by directly targeting its 3ʹUTR.Conclusion: The miR-1297/PFKFB2 axis regulated OS proliferation by controlling the Warburg effect. Our results revealed a previously undiscovered function of miR-1297 in OS, which strongly linked metabolic alterations with cancer progression. Targeting miR-1297 may become a promising therapeutic approach for OS.Keywords: osteosarcoma, miR-1297, PFKFB2, Warburg effect

Epidural fibrosis causes serious complications in patients who have undergone laminectomy. Pirfenidone is an effective antifibrotic agent but its effect on epidural fibrosis remains unclear. In this study, we aimed to investigate the effect of pirfenidone on epidural fibrosis and to evaluate its mechanism of action on human epidural scar fibroblasts. In a rat model of laminectomy, the degree of epidural fibrosis was quantified via Rydell standard classification, histological analysis, and collagen density analyses. In cultured human epidural scar fibroblasts, cell proliferation was measured using a Cell Counting Kit-8 and EdU assay. Cell apoptosis was detected using Annexin V/propidium iodide staining, and cytotoxicity was evaluated via lactate dehydrogenase assay. Relative mRNA levels of α-smooth muscle actin (α-SMA) and collagen type I were analyzed using quantitative polymerase chain reaction. The protein expression of α-SMA and collagen type I and the phosphorylation status of Smad2, Smad3, protein kinase B (Akt), and p38 were determined via western blotting. Pirfenidone reduced epidural fibrosis by inhibiting fibroblast proliferation and suppressing collagen formation in rats. It also inhibited human epidural scar fibroblast proliferation with no cytotoxic or apoptotic effects. Pirfenidone inhibited fibroblast differentiation by decreasing TGF-β1-induced transcriptional and translational expression of α-SMA. It inhibited TGF-β1-induced phosphorylation of Smad2, Smad3, Akt, and p38. This study suggests that topical application of pirfenidone could reduce epidural scar adhesion after laminectomy, and that its mechanism of action may be the inhibition of TGF-β1-induced epidural scar fibroblast proliferation and differentiation into myofibroblasts through the attenuation of TGF-β1-induced Smad-dependent and -independent pathways.

Considering the randomness of seismic input and the nonlinear characteristic of long-span structures, the probability density evolution method is used to study the dynamic response of the long-span steel-concrete composite structure under random earthquake. Three-dimensional structural model is established in the finite element software SAP2000, and then the displacements between layers and the response rule of vertical displacements of truss roof of the composite structure are obtained. The results show that under the input of three-dimensional earthquake, the vertical displacement of the grid roof of the isolated long-span steel-concrete composite structure is an order of magnitude larger than the horizontal direction of each layer. The probability density evolution method can offer comprehensive probability information of nodal displacements, and provide a reasonable way for the seismic reliability analysis of long-span isolated structures.

The fast and accurate identification of nerve tracts is critical for successful nerve anastomosis. Taking advantage of differences in acetylcholinesterase content between the spinal ventral and dorsal roots, we developed a novel quartz crystal microbalance method to distinguish between these nerves based on acetylcholinesterase antibody reactivity. The acetylcholinesterase antibody was immobilized on the electrode surface of a quartz crystal microbalance and reacted with the acetylcholinesterase in sample solution. The formed antigen and antibody complexes added to the mass of the electrode inducing a change in frequency of the electrode. The spinal ventral and dorsal roots were distinguished by the change in frequency. The ventral and dorsal roots were cut into 1 to 2-mm long segments and then soaked in 250 μL PBS. Acetylcholinesterase antibody was immobilized on the quartz crystal microbalance gold electrode surface. The results revealed that in 10 minutes, both spinal ventral and dorsal roots induced a frequency change; however, the frequency change induced by the ventral roots was notably higher than that induced by the dorsal roots. No change was induced by bovine serum albumin or PBS. These results clearly demonstrate that a quartz crystal microbalance sensor can be used as a rapid, highly sensitive and accurate detection tool for the quick identification of spinal nerve roots intraoperatively.

Pedicle screw placement in thoracic and lumbar spine is technically demanding and involves radiation exposure. Commercially available systems for pedicle screw insertion are expensive and cannot be widely used for those less-developed areas. The purpose of our study was to develop a simple guide device assisting pedicle screw placement and improving the accuracy in the operation. A simple guide device was developed with the aim of improving accuracy of pedicle screw technique based on anatomical structures of the spine. We retrospectively collected clinical data of 111 consecutive patients who received treatment of pedicle screw internal fixation between January 2013 and September 2014. In total, 518 screws were inserted by the same surgeon, among which 280 screws were implanted in 60 patients (33 males and 27 females) with conventional freehand technique and 238 screws were implanted in 51 patients (27 males and 24 females) using the guide device. According to postoperative CT evaluation, screws were classified into different grades and accuracy rates were compared between the two groups. A total of 518 screws were placed (238 in the guide group, 280 in the conventional group). No intra-operative or postoperative complications such as infection, vessel and nerve injuries occurred. After postoperative CT evaluation, 215 from guide group and 236 from the conventional group were classified in Grade 1. Only screws in Grade 1 were considered as accurate insertion. Thus, the accuracy rates were 84.3% for the conventional group and 90.3% for the guide group respectively. Through statistical test, there was significant difference in the accuracy rate between two groups. The simple guide device significantly improves the accuracy of pedicle screw placement. Combined with the advantage of cheapness, it can be widely used in spinal internal fixations, especially suitable for those inexperienced spine surgeons in less-developed areas.

A fiber optic fluorescence biosensor for choline is introduced in this paper. Choline is an important neurotransmitter in mammals. Due to the growing needs for on-site clinical monitoring of the choline, much effect has been devoted to develop choline biosensors. Fiber-optic fluorescence biosensors have many advantages, including miniaturization, flexibility, and lack of electrical contact and interference. The choline fiber-optic biosensor we designed implemented a bifurcated fiber to perform fluorescence measurements. The light of the blue LED is coupled into one end of the fiber as excitation and the emission spectrum from sensing film is monitored by fiber-spectrometer (S2000, Ocean Optics) through the other end of the fiber. The sensing end of the fiber is coated with Nafion film dispersed with choline oxidase and oxygen sensitive luminescent Ru(II) complex (Tris(2,2'-bipyridyl)dichlororuthenium(II), hexahydrate). Choline oxidase catalyzes the oxidation of choline to betaine and hydrogen peroxide while consuming oxygen. The fluorescence intensity of oxygen- sensitive Ru(II) are related to the choline concentration. The response of the fiber-optic sensor in choline solution is represented and discussed. The result indicates a low-cost, high-performance, portable choline biosensor.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.