Treatment of Syringomyelia Characterized by Focal Dilatation of the Central Canal Using Mesenchymal Stem Cells and Neural Stem Cells

Mo Li,Wang Xinyu,Qi Boling,Cui Shengyu,Zheng Tianqi,Guan Yunqian,Ma Longbing,Liu Sumei,Li Qian,Chen Zhiguo,Jian Fengzeng 한국조직공학과 재생의학회 2024 조직공학과 재생의학 Vol.21 No.4

BACKGROUND: Syringomyelia is a progressive chronic disease that leads to nerve pain, sensory dissociation, and dyskinesia. Symptoms often do not improve after surgery. Stem cells have been widely explored for the treatment of nervous system diseases due to their immunoregulatory and neural replacement abilities. METHODS: In this study, we used a rat model of syringomyelia characterized by focal dilatation of the central canal to explore an effective transplantation scheme and evaluate the effect of mesenchymal stem cells and induced neural stem cells for the treatment of syringomyelia. RESULTS: The results showed that cell transplantation could not only promote syrinx shrinkage but also stimulate the proliferation of ependymal cells, and the effect of this result was related to the transplantation location. These reactions appeared only when the cells were transplanted into the cavity. Additionally, we discovered that cell transplantation transformed activated microglia into the M2 phenotype. IGF1-expressing M2 microglia may play a significant role in the repair of nerve pain. CONCLUSION: Cell transplantation can promote cavity shrinkage and regulate the local inflammatory environment. Moreover, the proliferation of ependymal cells may indicate the activation of endogenous stem cells, which is important for the regeneration and repair of spinal cord injury. BACKGROUND: Syringomyelia is a progressive chronic disease that leads to nerve pain, sensory dissociation, and dyskinesia. Symptoms often do not improve after surgery. Stem cells have been widely explored for the treatment of nervous system diseases due to their immunoregulatory and neural replacement abilities. METHODS: In this study, we used a rat model of syringomyelia characterized by focal dilatation of the central canal to explore an effective transplantation scheme and evaluate the effect of mesenchymal stem cells and induced neural stem cells for the treatment of syringomyelia. RESULTS: The results showed that cell transplantation could not only promote syrinx shrinkage but also stimulate the proliferation of ependymal cells, and the effect of this result was related to the transplantation location. These reactions appeared only when the cells were transplanted into the cavity. Additionally, we discovered that cell transplantation transformed activated microglia into the M2 phenotype. IGF1-expressing M2 microglia may play a significant role in the repair of nerve pain. CONCLUSION: Cell transplantation can promote cavity shrinkage and regulate the local inflammatory environment. Moreover, the proliferation of ependymal cells may indicate the activation of endogenous stem cells, which is important for the regeneration and repair of spinal cord injury.

METTL3 promotes adriamycin resistance in MCF-7 breast cancer cells by accelerating pri-microRNA-221-3p maturation in a m6A-dependent manner

Pan Xiaoping,Hong Xiaolv,Li Sumei,Meng Ping,Xiao Feng 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Breast cancer (BC) is the most prevalent malignant neoplasm among women and is the fifth most common cause of cancer-associated death worldwide. Acquired chemoresistance driven by genetic and epigenetic alterations is a significant clinical challenge in treating BC. However, the mechanism of BC cell resistance to adriamycin (ADR) remains to be elucidated. In this study, we identified the methyltransferase-like 3/microRNA-221-3p/homeodomain-interacting protein kinase 2/Che-1 (METTL3/miR-221-3p/HIPK2/Che-1) axis as a novel signaling event that may be responsible for resistance of BC cells to ADR. A dual-luciferase reporter gene assay was employed to test the presence of miR-221-3p binding sites in the 3′UTR of HIPK2. Drug resistance was evaluated by immunoblotting multidrug resistance protein 1 (MDR1) and breast cancer resistance protein (BCRP). Cultured ADR-resistant MCF-7 cells were assayed for their half maximal inhibitory concentration (IC50) values and apoptosis using an MTT assay and Annexin V-FITC/PI-labeled flow cytometry, and the cells were then xenografted into nude mice. METTL3 knockdown was shown to reduce the expression of miR-221-3p by reducing pri-miR-221-3p m6A mRNA methylation, thereby reducing the IC50 value of ADR-resistant MCF-7 cells, reducing the expression of MDR1 and BCRP, and inducing apoptosis. Mechanistically, miR-221-3p was demonstrated to negatively regulate HIPK2 and upregulate its direct target Che-1, thus leading to enhanced drug resistance in ADR-resistant MCF-7 cells. In vitro results were reproduced in nude mice xenografted with ADR-resistant MCF-7 cells. Our work elucidates an epigenetic mechanism of acquired chemoresistance in BC, in support of the METTL3/miR-221-3p/HIPK2/Che-1 axis as a therapeutic target for the improvement of chemotherapy.

Hysteretic Analysis and a Simplifi ed Model of Buckling Restrained Steel Plate Shear Walls

Lanhui Guo,Jian Hou,Zhiguo Li,Sumei Zhang 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.1

As a kind of new lateral resistance member, buckling restrained steel plate shear walls (BRSPSWs) possess good ductility and energy dissipation ability, which begin to be used in buildings. In the use of BRSPSWs, it is hard to simulate BRSPSWs in high-rise buildings using shell elements due to convergence problems. Hence, a simplifi ed analysis model for BRSPSWs is needed by engineers. In this paper, the fi nite element analysis of BRSPSWs under cyclic loads was done. The available experimental results are applied to validate the accuracy of fi nite element analysis results. Then the behavior of typical BRSPSW under cyclic loads is analyzed. Also, the infl uence of bolt distance, reinforced concrete (RC) panels’ thickness, height-to-thickness ratio and span-to-height ratio of steel plate on the hysteretic behavior of BRSPSWs is studied. The analytical results show that the bolt distance and RC panel thickness have obvious infl uence on the energy dissipation ability. At last, a simplifi ed model is proposed, which can be used to simulate the hysteretic behavior of BRSPSWs instead of shell element in high-rise buildings.

Effects of Chitosan on Body Weight Gain, Growth Hormone and Intestinal Morphology in Weaned Pigs

Xu, Yuanqing,Shi, Binlin,Yan, Sumei,Li, Tiyu,Guo, Yiwei,Li, Junliang Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.10

The study was conducted to determine the effects of chitosan on the concentrations of GH and IGF-I in serum and small intestinal morphological structure of piglets, in order to evaluate the regulating action of chitosan on weaned pig growth through endocrine and intestinal morphological approaches. A total of 180 weaned pigs (35 d of age; $11.56{\pm}1.61kg$ of body weight) were selected and assigned randomly to 5 dietary treatments, including 1 basal diet (control) and 4 diets with chitosan supplementation (100, 500, 1,000 and 2,000 mg/kg, respectively). Each treatment contained six replicate pens with six pigs per pen. The experiment lasted for 28 d. The results showed that the average body weight gain (BWG) of pigs was improved quadratically by dietary chitosan during the former 14 d and the later 14 d after weaned (p<0.05). Furthermore, dietary supplementation of chitosan tended to quadratically increase the concentration of serum GH on d 14 (p = 0.082) and 28 (p = 0.087). Diets supplemented with increasing levels of chitosan increased quadratically the villus height of jejunum and ileum on d 14 (p = 0.089, p<0.01) and 28 (p = 0.074, p<0.01), meanwhile, chitosan increased quadratically the ratio of villus height to crypt depth in duodenum, jejunum and ileum on d 14 (p<0.05, p = 0.055, p<0.01) and 28 (p<0.01, p<0.01, p<0.01), however, it decreased quadratically crypt depth in ileum on d 14 (p<0.05) and that in duodenum, jejunum and ileum on d 28 (p<0.01, p<0.05, p<0.05). In conclusion, these results indicated that chitosan could quadratically improve growth in weaned pigs, and the underlying mechanism may due to the increase of the serum GH concentration and improvement of the small intestines morphological structure.

High-performance Zinc-Tin-Oxide thin film transistors based on environment friendly solution process

Qian Zhang,Guodong Xia,Lubin Li,Wenwen Xia,Hong-Yu Gong,Sumei Wang 한국물리학회 2019 Current Applied Physics Vol.19 No.2

Zinc-Tin-Oxide (ZTO) thin films were fabricated using a simple and eco-friendly sol-gel method and their application in thin film transistors (TFTs) was investigated. Annealing temperature has a crucial influence on the structure and electrical properties of sol-gel ZTO thin films. The ZTO thin films annealed at 300–600 °C revealed smooth and uniform surfaces with amorphous state, in addition, a high optical transparency over 90% of the ZTO films in the visible range was obtained. The electrical performance of ZTO TFTs showed obvious dependence on annealing temperature. The ZTO TFTs annealed at 500 °C showed a high carrier mobility of 5.9 cm2 /V, high on/off current ratio (Ion/off) of 106 -107 , and threshold voltage (Vth) of 1.03 V. To demonstrate the application of sol-gel ZTO films in low-power display fields, we also fabricated ZTO TFTs with a solution-processed high-permittivity (high-k) ZrTiOx dielectric layer. The ZTO/ZrTiOx TFTs showed high mobility of 17.9 cm2 /V and Ion/off of 105 -106 at a low operation voltage of 3 V, indicating that Indium-free ZTO thin films would be potential candidates for low cost, high performance oxide TFT devices.

Hysteretic Analysis of Thin Steel Plate Shear Walls

Lanhui Guo,Mingming Jia,Ran Li,Sumei Zhang 한국강구조학회 2013 International Journal of Steel Structures Vol.13 No.1

Thin steel plate shear walls (TSPSWs) are especially concerned due to the economic factor and excellent energy dissipation capacity. TSPSWs commonly define as steel plate with height-to-thickness ratio over 300. The post-buckling capacity,deformability and energy dissipation capacity of TSPSWs are now accepted by structural engineers. This brings about evident economic benefit. This paper presents a finite element analysis of TSPSWs under cyclic loading. The calculated results are compared with experimental results to validate its accuracy. Then based on the finite element model, the influence of heightto-thickness ratio and span-to-height ratio on the hysteretic behavior of TSPSWs is analyzed. Also, the influence of column moment rigidity on the development of tension field is studied. At last, a new simplified Combined Strip Model is introduced which is suitable for the hysteretic analysis of TSPSWs. Based on the Combined Strip Model, a formula for calculating shear strength is proposed, which considers the compression effects of TSPSWs.

SAXS investigations of the fractal character of additive silica xerogels

Fei He,Xiaodong He,Mingwei Li,Sumei Zhang 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.4

Two-step acid-base catalyzed silica xerogels with different amounts of additives, including TiO2 powder, silica xerogel powders and short glass fibers, were prepared through a sol-gel route and ambient pressure drying. The fractal dimensions of these additive silica xerogels were investigated by the means of small-angle X-ray scattering (SAXS). Specific surface area and the average chord length were calculated by the Debye method. The changes of the porous structure were compared between the pure silica xerogels and the impure ones. The results show that additive silica xerogels do not possess a surface fractal character. The mass fractal range of silica xerogels decreases and colloid particle size increases with an increase of additives. The adding of excessive silica xerogel powders results in agglomeration of particles which goes beyond the metrical limit of SAXS. The mass fractal dimension and fractal range decrease with the addition of additional short fibers. The shrinkage was restrained in the course of drying by adding short fibers Two-step acid-base catalyzed silica xerogels with different amounts of additives, including TiO2 powder, silica xerogel powders and short glass fibers, were prepared through a sol-gel route and ambient pressure drying. The fractal dimensions of these additive silica xerogels were investigated by the means of small-angle X-ray scattering (SAXS). Specific surface area and the average chord length were calculated by the Debye method. The changes of the porous structure were compared between the pure silica xerogels and the impure ones. The results show that additive silica xerogels do not possess a surface fractal character. The mass fractal range of silica xerogels decreases and colloid particle size increases with an increase of additives. The adding of excessive silica xerogel powders results in agglomeration of particles which goes beyond the metrical limit of SAXS. The mass fractal dimension and fractal range decrease with the addition of additional short fibers. The shrinkage was restrained in the course of drying by adding short fibers

Comparison of cecal microbiota composition in hybrid pigs from two separate three-way crosses

Yang, Yuting,Shen, Liyan,Gao, Huan,Ran, Jinming,Li, Xian,Jiang, Hengxin,Li, Xueyan,Cao, Zhenhui,Huang, Ying,Zhao, Sumei,Song, Chunlian,Pan, Hongbin Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.7

Objective: The intestinal microbiota plays an important role in host physiology, metabolism, immunity, and behavior. And host genetics could influence the gut microbiota of hybrid animals. The three-way cross model is commonly utilized in commercial pig production; however, the use of this model to analyse the gut microbial composition is rarely reported. Methods: Two three-way hybrid pigs were selected, with Saba pigs as the starting maternal pig: Duroc× (Berkshire×Saba) (DBS) pig, Berkshire×(Duroc×Saba) (BDS) pig. One hundred pigs of each model were reared from 35 days (d) to 210 d. The body weight or feed consumption of all pigs were recorded and their feed/gain (F/G) ratio was calculated. On day 210, 10 pigs from each three-way cross were selected for slaughter, and cecal chyme samples were collected for 16S rRNA gene sequencing. Results: The final body weight (FBW) and average daily gain (ADG) of DBS pigs were significantly higher than those of BDS pigs (p<0.05), while the F/G ratios of DBS pigs were significantly lower than those of BDS pigs (p<0.05). The dominant phyla in DBS and BDS pigs were Bacteroidetes (55.23% vs 59%, respectively) and Firmicutes (36.65% vs 34.86%, respectively) (p>0.05). At the genus level, the abundance of Prevotella, Roseburia, and Anaerovibrio in DBS pigs was significantly lower than in BDS pigs (p<0.01). The abundance of Eubacterium, Clostridium XI, Bacteroides, Methanomassiliicoccus, and Parabacteroides in DBS pigs was significantly higher than in BDS pigs (p<0.05). The FBWs and ADGs were positively correlated with Bacteroides, ClostridiumXI, and Parabacteroides but negatively correlated with the Prevotella, Prevotella/Bacteroides (P/B) ratio, Roseburia, and Anaerovibrio. Conclusion: These results indicated that host genetics affect the cecal microbiota composition and the porcine gut microbiota is associated with growth performance, thereby suggesting that gut microbiota composition may be a useful biomarker in porcine genetics and breeding.

A High-Efficiency Bidirectional AC/DC Topology for V2G Applications

Su, Mei,Li, Hua,Sun, Yao,Xiong, Wenjing The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.5

This paper proposes a single-phase bidirectional AC/DC converter topology applied in V2G systems, which consists of an inverter and a bidirectional non-inverting buck-boost converter. This topology can operate in four modes: buck charging, boost charging, buck discharging and boost discharging with high input current quality and unity input power factor. The inverter switches at line frequency, which is different from conventional voltage source inverters. A bidirectional buck-boost converter is utilized to adapt to a wider charging voltage range. The modulation and control strategy is introduced in detail, and the switching patterns are optimized to reduce the current ripple. In addition, the semiconductor losses are analyzed. Simulation and experimental results demonstrate the validity and effectiveness of the proposed topology.