Objective To explore the effect of tissue engineered cartilage reconstructed by using sodium alginate hydrogel and SIS complex as scaffold material and chondrocyte as seed cell on the repair of full-thickness articular cartilage defects. Methods SIS was prepared by custom-made machine and detergent-enzyme treatment. Full-thickness articularcartilage of loading surface of the humeral head and the femoral condyle obtained from 8 New Zealand white rabbits (2-3weeks old) was used to culture chondrocytes in vitro. Rabbit chondrocytes at passage 4 cultured by conventional multipl ication method were diluted by sodium alginate to (5-7) × 107 cells/mL, and then were coated on SIS to prepare chondrocyte-sodium alginate hydrogel-SIS complex. Forty 6-month-old clean grade New Zealand white rabbits weighing 3.0-3.5 kg were randomized into two groups according to different operative methods (n=20 rabbits per group), and full-thickness cartilage defect model of the unilateral knee joint (right or left) was establ ished in every rabbit. In experimental group, the complex was implanted into the defect layer by layer to construct tissue engineered cartilage, and SIS membrane was coated on the surface to fill the defect completely. While in control group, the cartilage defect was filled by sodium alginate hydrogel and was sutured after being coated with SIS membrane without seeding of chondrocyte. General condition of the rabbits after operation was observed. The rabbits in two groups were killed 1, 3, 5, 7, and 9 months after operation, and underwent gross and histology observation. Results Eight rabbits were excluded due to anesthesia death, wound infection and diarrhea death. Sixteen rabbits per group were included in the experiment, and 3, 3, 3, 3, and 4 rabbits from each group were randomly selected and killed 1, 3, 5, 7, and 9 months after operation, respectively. Gross observation and histology Masson trichrome staining: in the experimental group, SIS on the surface of the implant was fused with the host tissue, and the inferface between them disappeared 1 month after operation; part of the implant was chondrified and the interface between the implant and the host tissue was fused 3 months after operation; the implant turned into fibrocartilage 5 months after operation; fiber arrangement of the cartilage in theimplant was close to that of the host tissue 7 months after operation; cartilage fiber in the implant arranged disorderly andactive cell metabol ism and prol iferation were evident 9 months after operation. While in the control group, no repair of thedefect was observed 9 months after operation. No obvious repair was evident in the defects of the control group within 9months after operation. Histomorphometric evaluation demonstrated that the staining intensity per unit area of the reparative tissue in the defect of the experimental group was significant higher than that of the control group at each time point (P lt; 0.05), the chondrification in the experimental group was increased gradually within 3, 5, and 7 months after operation (P lt; 0.05), and it was decreased 9 months after operation comparing with the value at 7 months after operation (P lt; 0.05). Conclusion Constructed by chondrocyte-sodium alginate hydrogel-SIS in complex with surficial suturing of SIS membrane, the tissue engineered cartilage can in-situ repair cartilage defect, promote the regeneration of cartilage tissue, and is in l ine with physiological repair process of articular cartilage.
【Abstract】 Objective To explore an effective method to cultivate esophageal mucosa epithel ial cells (EMECs)of canine in vitro, and to observe the biological characteristics of EMECs growing on SIS in order to provide an experimental basis for esophagus tissue engineering. Methods Esophageal tissues were obtained from five healthy dogs aged 2 to 5 weeks under sterile conditions. The primary EMECs were cultivated with defined keratinocyte serum free medium (DKSFM) containing 6% FBS. The morphological characteristics and the growth curve of EMECs of the 2nd generation were observed for 1 to 5 days. The expressions of the EMECs marker (cytokeratin 19, CK-19) were examined by immunocytochemistry. The 2nd generation of EMECs was seeded on SIS and observed by HE staining, immunohistochemical staining, and SEM for 4 and 8 days. Results The primary culture of canine EMECs arranged l ike slabstone. Immunohistochemical staining of CK-19 of the2nd generation EMECs showed positive broadly. The cells growth reached the peak level at 2 days by MTT method. E MECs werepolygon in shape and arranged l ike slabstone, and formed a single layer on the surface of SIS. The cells were contact ed closely with each other for 4 days. Eight days later, 2 to 3 layers stratified structure was formed. Lots of EMECs were grown on SIS, andshowed laminate arrangement. Conclusion With mixed enzymatic digestion, the culture of EMECs in DKSFM containing 6 %FBS is a simple and feasible method. SIS shows good biocompatibil ity and can be used as a good scaffold material in th e tissue engineered esophagus.
ObjectivesTo investigate residents’ sensitivity towards basic public health services in Sichuan province, so as to provide advice on future improvement.MethodsUsing multistage stratified sampling and through consultation of the Sichuan province's basic public health service regulatory platform to select 40 equidistant samples from the five key population groups. Specifically, 200 individuals from each of the 21 cities were enrolled. Telephone survey was conducted to acquire residents’ awareness rate, satisfaction and compliance. Technique for order preference by similarity to an ideal solution (TOPSIS) was applied to comprehensively evaluate residents’ sensitivity of basic public health services.ResultsA total of 4 200 community residents who have accepted health managements in basic health care institutions were enrolled. The mean Cj value was 0.523 6. The No.4 city had the highest Cj value of 0.751 9, and the No.10 city had the lowest value of 0.276 3.ConclusionsThe residents’ sensitivity to basic public health services varies in 21 cities of Sichuan province. We should improve the quality of medical services in primary health care institutions and provide wide publicity to enhance the well-being and satisfaction of community residents. Government should improve the quality of medical services in primary health care institutions, and narrow the gap between different cities, so as to improve residents’ experience.
The comprehensive clinical evaluation of drugs is fundamental work that promotes drugs return to clinical value and it has become one of the most important areas of clinical pharmacy in recent years. The existing literature focuses on the construction of comprehensive clinical evaluation index system or the quantification of index values. However, relatively few studies concerning the value integration method, which may lead to the suboptimal scheme being selected as the optimal scheme. Therefore, this study summarizes various comprehensive value integration methods from the aspects of background, principles and applicable situations, to provide methodological references for comprehensive clinical evaluation in China.
【Abstract】 Objective To investigate the in vivo osteogenic feasibil ity of tissue engineered periosteum constructedby porcine SIS and BMSCs in allogenic New Zealand rabbit. Methods The tissue engineered periosteum constructed by SIS scaffold and BMSCs was prepared in vitro .Twelve 2-month-old New Zealand rabbits were used in the experiments. The 1.5-2.0 cm critical bone defects were made in the both sides of radius of the animals. The tissue engineered periosteum was grafted into one side defect randomly, while the other side defect was only grafted SIS. Four weeks after operation, the forearms of all animals were checked by X-ray. Then, animals were sacrificed to harvest the specimen which were treated promptly for HE and Masson staining.The X-ray film and the morphological tissue staining outcome were evaluated qual itatively. Results After operation,all animals had a normal behavior and diet; the incision healed normally; the forearm could move normally for bearing weight.The tissue engineered periosteum constructed by allogenic BMSCs and heterogeneic SIS scaffold could form new bone tissue, andbridged the bone defect which could be confirmed either in X-ray film or histological staining. The newly formed bone tissue had similar bone density to normal bone. A lot of irregular newly formed vessels and medullary cavity inserted in the newly borned tissue. No lymphocytes infiltrated in histological examination. While the control side had no any osteogenesis neithter in X-ray, nor in HE and Masson staining inspecting; the defect space only occupied with some connective tissue. Conc lu sion Tissue engineered periosteum can form new bone in allogenic rabbit and has the feasibil ity to repair the segmental diaphysis defect.
Kruppel-like Factor 4 (KLF4), a target gene of miR-145, can negatively regulate lung fibrosis. However, the potential role of KLF4 and miR-145 in hepatic stellate cells (HSCs) activation or in hepatic fibrosis keeps unclear. This study aims to characterize miR-145 and KLF4 in activated HSCs and liver cirrhotic, and the underlying molecular basis. miR-145 was significantly up-regulated, while KLF4 was dramatically down-regulated during the activation of rat primary HSCs and TGF-beta treated HSCs. Furthermore, miR-145 mimics induced and inhibition of miR-145 reduced a-SMA and COL-I expression in primary HSCs. Additionally, the mRNA and protein levels of KLF4 in the liver of cirrhotic patients and rats were significantly down-regulated. alpha-SMA and COL-I were increased after inhibition of KLF4 by specific shRNA in primary HSCs. Forced KLF4 expression led to a reduction of a-SMA and COL-I expression in HSCs. miR-145 promotes HSC activation and liver fibrosis by targeting KLF4.
Deferoxamine (DFO), an iron chelator, is commonly used to remove excess iron from the body. DFO has also been demonstrated to have anti-tumor effect. However, there is no available report on the effect of deferoxamine on mesenchymal stromal cells (MSCs). In this study, we first isolated tumor-associated MSCs (TAMSCs) from EG-7 tumors, which were positive for CD29, CD44, CD73, CD90 and CD105. Ex vivo cultured stem cells derived from tumor and bone marrow compartment were exposed to DFO. We demonstrated that DFO had growth-arresting and apoptosis-inducing effect on TAMSCs and bone marrow MSCs (BMMSCs). DFO also influenced the expression pattern of adhesion molecule VCAM-1 on both TAMSCs and BMMSCs. Notwithstanding its widespread use, our results here warrants caution in the application of DFO, and also highlights the need for careful evaluation of the bone marrow compartment in patients receiving DFO treatment. (C) 2016 Elsevier B.V. All rights reserved.
The attenuated Japanese encephalitis virus (JEV) strain SA14-14-2 has been successfully utilized to prevent JEV infection; however, the attenuation determinants have not been fully elucidated. The envelope (E) protein of the attenuated JEV SA14-14-2 strain differs from that of the virulent parental SA14 strain at eight amino acid positions (E107, E138, E176, E177, E264, E279, E315, and E439). Here, we investigated the SA14-14-2-attenuation determinants by mutating E107, E138, E176, E177, and E279 in SA14-14-2 to their status in the parental virulent strain and tested the replication capacity, neurovirulence, neuroinvasiveness, and mortality associated with the mutated viruses in mice, as compared with those of JEV SA14-14-2 and SA14. Our findings indicated that revertant mutations at the E138 or E107 position significantly increased SA14-14-2 virulence, whereas other revertant mutations exhibited significant increases in neurovirulence only when combined with E138, E107, and other mutations. Revertant mutations at all eight positions in the E protein resulted in the highest degree of SA14-14-2 virulence, although this was still lower than that observed in SA14. These results demonstrated the critical role of the viral E protein in controlling JEV virulence and identified the amino acids at the E107 and E138 positions as the key determinants of SA14-14-2 neurovirulence.
Through advances in analytical methods to detect glycoproteins and to determine glycan structures, there have been increasing reports of protein glycosylation in bacteria. In this review, we summarize the known pathways for bacterial protein glycosylation: lipid carrier-mediated 'en bloc' glycosylation; and cytoplasmic stepwise protein glycosylation. The exploitation of bacterial protein glycosylation systems, especially the 'mix and match' of three independent but similar pathways (oligosaccharyltransferase-mediated protein glycosylation, lipopolysaccharide and peptidoglycan biosynthesis) in Gram-negative bacteria for glycoengineering recombinant glycoproteins is also discussed.
Raman spectroscopy has demonstrated great potential in biomedical applications. However, spectroscopic Raman imaging is limited in the investigation of fast changing phenomena because of slow data acquisition. Our previous studies have indicated that spectroscopic Raman imaging can be significantly sped up using the approach of narrow-band imaging followed by spectral reconstruction. A multi-channel system was built to demonstrate the feasibility of fast wide-field spectroscopic Raman imaging using the approach of simultaneous narrow-band image acquisition followed by spectral reconstruction based on Wiener estimation in phantoms. To further improve the accuracy of reconstructed Raman spectra, we propose a stepwise spectral reconstruction method in this study, which can be combined with the earlier developed sequential weighted Wiener estimation to improve spectral reconstruction accuracy. The stepwise spectral reconstruction method first reconstructs the fluorescence background spectrum from narrow-band measurements and then the pure Raman narrow-band measurements can be estimated by subtracting the estimated fluorescence background from the overall narrow-band measurements. Thereafter, the pure Raman spectrum can be reconstructed from the estimated pure Raman narrow-band measurements. The result indicates that the stepwise spectral reconstruction method can improve spectral reconstruction accuracy significantly when combined with sequential weighted Wiener estimation, compared with the traditional Wiener estimation. In addition, qualitatively accurate cell Raman spectra were successfully reconstructed using the stepwise spectral reconstruction method from the narrow-band measurements acquired by a four-channel wide-field Raman spectroscopic imaging system. This method can potentially facilitate the adoption of spectroscopic Raman imaging to the investigation of fast changing phenomena. (C) 2017 Optical Society of America