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BACKGROUND: Previous studies have shown that a variety of materials can be used for the construction of tissue engineering scaffolds. The topological structure of the scaffold surface has a regulatory effect on the biological behaviors such as stem cell proliferation and differentiation, but the specific mechanism is still unclear. OBJECTIVE: To investigate the role of P38 and Akt pathways in the oriented differentiation of bone marrow mesenchymal stem cells in nanofiber scaffolds. METHODS: Three kinds of nanofiber scaffolds (AFS, AYS, 3-DPS) with different structures were constructed. Rat bone marrow mesenchymal stem cells were inoculated on the surface of three kinds of nanofiber scaffolds. After osteogenic induction, cell morphology, adhesion and proliferation were detected. mRNA expression levels of key phenotype molecules (COLIα1, COLIIα1, Aggrecan, Sox-9) were measured using qRT-PCR. Intracellular P38, AKT, ERK1/2 and JNK expression was detected by western blot assay. RESULTS AND CONCLUSION: After 4 and 8 hours of culture, cell adhesion rate of the 13-DPS scaffold group was higher than that of the AFS and AYS scaffold groups (P<0.05). After 7 days of culture, cells of the 13-DPS scaffold group proliferated faster than those of AFS and AYS scaffold groups (P<0.05). Bone marrow mesenchymal stem cells adhered firmly and grew well on three kinds of scaffolds. Fibroblast-like growth was observed on the AFS and AYS scaffolds and chondrocyte-like growth was observed on the 3-DPS scaffold. After 3 weeks of cartilage induction, mRNA expression of COLIIα1, Aggrecan and Sox-9 was higher, and the mRNA expression of COLIα1 was lower, in the 3-DPS scaffold group compared with the other two groups (both P<0.05). After 3 weeks of cartilage induction, relative expression level of p-AKT and p-P38 in the 3-DPS scaffold group was significantly higher than that in the other two groups (both P<0.05). There were no significant differences in AKT total protein and ERK1/2, JNK, P38, p-ERK1/2, p-JNK and p-P38 protein expression levels among three groups. These findings suggest that nanofiber annulus fibrosus scaffolds with different spatial structures can induce the oriented differentiation of bone marrow mesenchymal stem cells through the P38 and AKT pathway, which were the downstream of the Integrin-FAK signaling pathway.
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Objective To investigate the clinical outcomes using posterior percutaneous endoscopic cervical discectomy (PECD) for single level cervical spondylotic radiculopathy (CSR).Methods From October 2015 to June 2016,33 patients (23 men,10 women,mean age 54.0 years,range from 30 to 85 years) who had single level CSR were treated by PECD,and the medical records were reviewed.All patients were followed up for an average of 13.5±4.6 months (range from 12 to 22 months).The operation related parameters (operation time,estimated blood loss,length of hospitalization,complications) and clinical parameters,including neck visual analog scale (Neck-VAS),ann visual analog scale (Arm-VAS),neck disability index (NDI) and the modified Macnab criteria were assessed at 3,6,and 12 months postoperatively and last follow-up.Disc height,shell angle,C2-C7 Cobb angle and range of motion were recorded preoperatively and at 3 months,6 months,12 months and last follow-up postoperatively.Results The mean operation time was 76.4±26.6 minutes (range from 40 to 120 minutes),the mean estimated blood loss was 30.2±15.6 ml (range from 20 to 80 ml),and the mean length of hospitalization was 3.5± 1.1 days (range from 2 to 8 days).There was significant decrease at different time points postoperatively in Neck-VAS,Arm-VAS,and NDI when compared with preoperatively (P＜ 0.05).According to the modified Macnab criteria,there was excellent concordance in 20 patients (60.6％),good in 7 patients (21.2％) and fair in 6 patients (18.2％) at the last follow-up.The disc height was significantly decreased at postoperative 3 months and 1 year compared with at preoperative (F=95.1,P＜0.01).The shell angle of index level (F=35.4.,P＜0.01),upper adjacent level (F=30.1,P＜0.01),lower adjacent level (F=1 1.7,P＜0.01) as well as spinal function units (F=22.2,P＜0.01) were increased significantly at postoperative compared with at preoperative.The range of motion of index level (F=8.1,P＜0.01) and upper adjacent level (F=64.0,P＜0.01) increased significantly at postoperative compared with at preoperative.The range of motion in lower adjacent level (F=1.5,P=0.23),spine functional unit of index level (F=2.9,P=0.06),as well as C2-C7 (F=0.6,P=0.56) had no significant difference between preoperative and postoperative 1 year (P＞0.05).One patient turned into traditional ACDF procedure because of hemorrhage limiting the vision during PECD operation.Upper extremity numbness and pain deteriorated in one case after a PECD procedure and was revised with ACDF at last.No other complications,like spinal cord injury,cervical root injury,cerebral spinal fluid leakage,infection as well as recurrence were found.Conclusion PECD,which can maintain normal cervical range of motion and intervertebral disc height,is a minimally invasive and essential procedure for CSR treatment with minor trauma,excellent outcome and quick recovery.Surgeon's experience,however,is needed in case of turning into open surgery for good outcome.
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Objective To demonstrate the imaging characteristics of pancreatic neuroendocrine neoplasm (P-NEN).Methods The CT and MRI findings of 43 cases of P-NEN confirmed by pathology were analyzed,and compared with pathological results.Results Mean size of 43 lesions in 43 P-NEN patients were (25.00± 1.82)mm.Necrosis cystic degeneration were found in 26 lesions.In CT plain scan,15 lesions were isodense,28 lesions were hypodense.All of 43 lesions were hypointensity signal on T1WI;27 lesions were hypointensity signal,16 cases were isointensity signal on T2WI.Twenty-seven lesions showed envelope;30 lesions showed clear outline.In enhancement images,24 lesions were marked enhancement since arterial phase;8 lesions showed delayed enhancement;5 lesions showed centrality enhancement;6 lesions showed wild enhancement.Conclusion P-NEN has some characteristics on CT and MRI scanning,imaging can play an important role in diagnosis for P-NEN.
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This study reported the obtainment of the full-length cDNA of Salvia miltiorrhiza hairy roots (Abbr: SmHDR, GenBank number: JX233817), via extracting Salvia miltiorrhiza hairy roots total RNA, designing specific primers according to the transcriptome data and using the RACE strategy, and then analyzed it with bioinformatics approaches. On this basis, using the real-time PCR to detect SmHDR gene expression after Ag+ induction, and testing tanshinones contents of corresponding samples by UPLC. SmHDR has 1 647 nucleotides, and an open reading frame (ORF) encoding a protein of 463 amino acid residues. The deduced protein has isoelectric point (pI) of 5.72 and a calculated molecular weight about 51.88 kD. In the secondary structure, the percentage of alpha helix, beta turn and random coil were 35.64%, 20.30% and 44.06%, respectively. Sequence alignment and phylogenetic analysis demonstrated that SmHDR had relative close relationship to the HDR of Picrorhiza kurrooa, similar to HDR from other species of plants. Real time PCR results indicated that elicitor of Ag+ stimulated the increase of mRNA expression of SmHDR. At the same time, results of ultra performance liquid chromatography (UPLC), used to examine the accumulation of diterpenoid tanshinones in hairy roots, showed that the contents of diterpenoid tanshinones in hairy roots of Salvia miltiorrhiza were increased dramatically at 12 h after treated with Ag+, and then decreased significantly. This result showed a positive correlation between the levels of mRNA expression and tanshinones accumulation in Salvia miltiorrhiza stimulated by Ag+. The content of tanshinones was gradually raised, and it had an obvious increase at 120 h. The bioinformatics analysis and gene expression indicated that SmHDR might be involved in tanshinones biosynthesis, which laid the foundation for further study of secondary metabolic regulation mechanism of tanshinones.
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Diterpenes, an important class of natural compounds, are widely distributed in nature. As the valuable diterpenoids continue to be found, diterpene synthase in the course of diterpene synthesis get as much attention as possible. The multiformity of end-product-diterpenoids were also due to the diversity of diterpene synthase. This paper focuses on the advances in recent biosynthesis pathway of diterpene and types, cloning, catalytic mechanism, synthetic biology application.
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The application of elicitors, which is currently the focus of research, has been considered as one of the most effective methods to improve the synthesis of secondary metabolites in medicinal plants. Biotic and abiotic elicitors can regulate the secondary metabolic pathways of effective ingredients in Salvia miltiorrhiza. This paper has introduced the research progress about the induction and the regulation mechanism of S. miltiorrhiza by elicitors.