Objective To investigate the effect of carboxymethylated chitosan (CMCS) on the proliferation, cell cycle, and secretion of neurotrophic factors in cultured Schwann cells (SCs). Methods SCs were obtained from sciatic nerves of 20 Sprague Dawley rats (3-5 days old; male or female; weighing, 25-30 g) and cultured in vitro, SCs were identified and purified by immunofluorescence against S-100. The cell counting kit 8 (CCK-8) assay was used to determine the proliferation of SCs. The SCs were divided into 4 groups: 50 μg/mL CMCS (group B), 100 μg/mL CMCS (group C), 200 μg/mL CMCS (group D), and the same amount of PBS (group A) were added. The flow cytometry was used to analyze the cell cycle of SCs; the real-time quantitative PCR and Western blot analysis were used to detect the levels of never growth factor (NGF) and ciliary neurotrophic factor (CNTF) in cultured SCs induced by CMCS. Results The purity of cultured SCs was more than 90% by immunofluorescence against S-100; the CCK-8 results indicated that CMCS in concentrations of 10-1 000 μg/mL could promote the proliferation of SCs, especially in concentrations of 200 and 500 μg/mL (P lt; 0.01), but no significant difference was found between 200 and 500 μg/mL (P gt; 0.05). CMCS at a concentration of 200 μg/mL for 24 hours induced the highest proliferation, showing significant difference when compared with that at 0 hour (P lt; 0.01). The percentage of cells in phase S and the proliferation index were significantly higher in groups B, C, and D than in group A (P lt; 0.05), in groups C and D than in group B (P lt; 0.05); and there was no significant difference between group C and group D (P gt; 0.05). Real-time quantitative PCR and Western blot results showed that the levels of NGF and CNTF in groups B, C, and D were significantly higher than those in group A (P lt; 0.05), especially in group D. Conclusion CMCS can stimulate the proliferation, and induce the synthesis of neurotrophic factors in cultured SCs.
Objective To observe the ability to repair bilateralradius bone defect with the composite of β-tricalciumphosphate(βTCP),hyaluronic acid(HA),type I collagen(COL-Ⅰ) and induced marrow stromal cells(MSCs), and to investigate the feasibility of the composite as a bone substitute material.Methods The MSCs of the New Zealand white rabbits were induced into ostoblasts, then combined with β-TCP, HA and COL-Ⅰ. Thirty New Zealand white rabbits were made the bilateral radius bone defects of 2 cm and divided into groups A, B and C. After 8 weeks, β-TCP-HA-COL-Ⅰ-MSCs （group A, n=27 sides）, autograft （group B, n=27 sides）andno implant（group C as control, n=6 sides）were implanted into the areas ofbilateral radius bone defects, respectively. The structure of the composite was observed by scanning electron microscope. The repairing effect was observed by gross, histomorphology, X-ray examination, and the degradation rate of inorganic substance at 4, 8 and 12 weeks. The ostogenic area and biomechanics ofgroup A were compared with those of group B at 12 weeks.Results The MSCs could stably grow in vitro, relatively rapidly proliferated, and could be induced into the ostoblasts.The composite was porous. The results of gross, histomorphology and X-ray showed that the bone defects were perfectly repaired in group A and group B, but not in group C. The ostogenic area or biomechanics had no statistically significant difference between groups A and B(Pgt;0.05). The weight of inorganic substance in group A were 75% ,57% and 42% at 4,8,12 weeks, respectively.Conclusion MSCs can be used as seedcells in the bone tissue engineering. The composite has porous structure, no reactions of toxicity to the tissue and rapid degradation, and it is an ideal carrier of seed cells.The β-TCP-HA-COL-Ⅰ-MSCs composite has the high ability of repairing bone defect and can serve as an autograft substitute material.
Objective To investigate the effect of TNF-related weak inducer of apoptosis/fibroblast growth Factor-inducible 14 (TWEAK/Fn14) on the cell proliferation by transfecting Fn14 shRNA to PANC-1 cells. Methods The shRNA gene targeting Fn14 gene was constructed and transfected into pancreatic cancer cell line PANC-1 to specifically silence the expression of Fn14 gene. The effect of shRNA interference sequence on the expression of Fn14 was detected by flow cytometry and immunofluorescence. CCK-8 was used to detect the cell proliferation of PANC-1 after blocking TWEAK-induced signal pathway. Western blotting method was used to detect the expressions of downstream factors such as nuclear factor-kappa B (NF-κB), TWEAK and caspase-3 to explore the pathway mechanism of TWEAK/Fn14. Results The absorbance value (A value) in the Fn14 shRNA group was significantly lower than the control groups in 24 hours after transfected (P<0.000 1). After the specific shRNA sequences transfected PANC-1 cells, NF-κB, TWEAK and caspase-3 protein expressions were also significantly lower than the control group (P<0.05), and the apoptosis of PANC-1 cells increased after inhibition of TWEAK/Fn14 signaling pathway. Conclusions TWEAK/Fn14 involved in the progression of pancreatic cancer. The Fn14 expression could influence the process of cell apoptosis.
Objective To analyze the clinical characteristics of the Guang’an Omicron epidemic and summarize the management experiences and practices in pandemic prevention and control of major infectious diseases.Methods Retrospective analysis was performed on patients infected with coronavirus disease (COVID-19), afterwards treated and observed in the isolation ward of Guang’an People’s Hospital and the shelter of Guang’an City from May 9 to June 26, 2022. The characteristics of patients at different age stages and the related factors affecting the severity, re-positive and negative conversion was analyzed. Results Finally 1 278 patients were collected, including 508 males and 770 females, with an average age of 41.3±22.6 years. Among them, 1 054 patients were asymptomatic carriers. The overall severe rate was 0.86%, the severe rate of the high-risk group was 3.06%. The median negative conversion time was 10.0 days and re-positive rate was 7.36%. Patients aged＞60 years were 2.589 times more likely to have a longer negative conversion time than those aged≤60 years (95%CI 1.921-3.489, P＜0.001). Conclusion The clinical characteristics of Guang’an COVID-19 epidemic are mainly that the elderly with high risk factors are more likely to develop severe cases, have longer clearance time, and re-positve is more likely to occur.
ObjectiveTo reveal and demonstrate the hotspots and further research directions in screening technology for early lung cancer, and provide references for the future studies. MethodsResearches related to lung cancer screening from 2011 to 2021 in the Web of Science database were included. Biblioshiny, a bibliometrics program based on R language, was used to perform content analysis and visualization of the included literature information. ResultsResearches related to lung cancer screening were increasing year by year. Six major cooperation groups were formed between countries. The current research hotspots in the field of early lung cancer screening technology mainly focused on the multi-directional fusion of radiographic imaging, liquid biopsy and artificial intelligence. ConclusionLow-dose spiral CT screening is still the most important and mainstream method for the screening of early lung cancer at present. The combination and integration of artificial intelligence with various screening methods and the innovation of novel testing and diagnostic equipment are the current research hotspots and the future research trend in this field.