1.Convergence Study of Government Health Care Expenditure Based on the Provincial Panel Data
Chinese Health Economics 2013;(9):9-12
Objective: To analyze the convergence trend of the government health care expenditure, propose political advices to improve the balanced collocation of the inter-area government health care expenditure. Methods: The data of 31 provinces of China in 10 years period between 2000 and 2010 are adopted, the fixed panel model are used to analyze the convergence trend. Results:Government health care expenditure per capita in China exists σ-convergence, while the absolute β-convergence does not exist. Conclusion:The provincial government health expenditure in China has a trend of convergence.
2.Measurement and analysis of government health expenditures and health efficiency
Haixiang XIAO ; Tianshu CAO ; Liwei TANG
Chinese Journal of Health Policy 2014;(11):71-77
Objective:To calculate the health efficiency of government health expenditures in 1990 , 2000 and 2010 and analyze its determinants. Methods:To calculate the health efficiency of government health expenditures and analyze its determinants by using the DEA-Tobit model. Results:Health efficiency of government health expenditures has been increasing gradually;the same provinces are found to be on the productive frontier, but the provinces off the frontier are different;eastern provinces have a higher efficiency than those in the middle and western regions. Fiscal decentralization has a significant negative impact on health efficiency. Conclusion:The current Chinese fiscal decen-tralization system reform is important to improve the health efficiency of government health expenditures.
3.Preparation of a thermosensitive hydrogel scaffold combined with bone marrow mesenchymal stem cells
Yinan LI ; Guangfeng LI ; Xinmin FENG ; Cheng HUANG ; Haixiang XIAO ; Jiandong YANG
Chinese Journal of Tissue Engineering Research 2013;(42):7435-7441
BACKGROUND:Scaffolds made of chitosan and its derivatives play an important role in cellmigration and axonal regeneration. Chitosan and its derivatives have good histocompatibility, which is easy to make stem cells grow on the surface, thereby having a more broad application prospect in the nerve tissue engineering.
OBJECTIVE:To fabricate a thermosensitive hydrogel scaffold using chitosan/hydroxypropyltrimethyl ammonium chloride chitosan/sodium glycerophosphate (CS/HACC/GP), which is suitable for cellgrowth, and then, to observe the growth and proliferation of bone marrow mesenchymal stem cells on the scaffold.
METHODS:Chitosan was modified using quaternary ammonium salt and confirmed by Fourier transform infrared spectroscopy. The chitosan and quaternary ammonium salt of chitosan was mixed at a ratio of 8:1 to successful y prepare stable CS/HACC/GP thermosensitive hydrogel scaffold. Then, the gel ing was observed, and biosafety test was conducted.
RESULTS AND CONCLUSION:Fourier transform infrared spectroscopy showed the characteristic peak of quaternary ammonium groups. Cytotoxicity test showed that rat bone marrow mesenchymal stem cells cultured in hydrogel extracts had no toxicity. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test showed that hydrogel extracts exerted no significant effect on the increase in body weight, and the biological safety of the scaffold was good. Under the scanning electron microscopy, bone marrow-derived mesenchymal stem cells grew and proliferated normal y in the scaffold. The results confirmed that the CS/HACC/GP thermosensitive hydrogel scaffold was successful y prepared in the experiment, which is suitable for the growth and proliferation of bone marrow mesenchymal stem cells.
4.Neuron-like differentiation of mesenchymal stem cells induced by quaternary chitosan thermosensitive hydrogel scaffolds combined with glial cell line-derived neurotrophic factor
Cheng HUANG ; Jiandong YANG ; Xinmin FENG ; Guangfeng LI ; Yinan LI ; Haixiang XIAO ; Yu SUN
Chinese Journal of Tissue Engineering Research 2013;(42):7420-7426
BACKGROUND:In recent years, chitosan-based thermosensitive hydrogel, as scaffold materials, have received more and more attentions in the field of tissue repair because of good biocompatibility, biodegradability and drug-sustained release.
OBJECTIVE:To explore the directed differentiation and growth of rat bone marrow mesenchymal stem cells on the quaternary chitosan thermosensitive hydrogel scaffold and to look for more ideal tissue engineering materials for the treatment of nervous system damage.
METHODS:The thermosensitive hygrogel scaffold was prepared using hydroxypropyltrimethyl ammonium chloride chitosan (HACC) andβ-glycerophosphate (β-GP). The spatial structure of scaffold was observed by scanning electronic microscope. Effect of leaching liquor from the HACC/β-GP scaffold on the viability of bone marrow mesenchymal stem cells was detected by (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The albumin from bovine serum was combined with the scaffold, and the slow-release effect of the scaffold was detected by ultraviolet absorption spectrometry. Bone marrow mesenchymal stem cells were incubated onto the compound scaffold at 3 passages. The adhesion, growth and differentiation of bone marrow mesenchymal stem cells on the compound scaffold were observed by the scanning electron microscope. Neuron-specific enolase was detected by immunofluorescence.
RESULTS AND CONCLUSION:The porosity and thermal sensitivity of HACC/β-GP scaffold and slow-release effect of glial cellline-derived neurotrophic factor were apparent. The results of MTT showed that the compound scaffold cannot take apparent negative effects to the proliferation of bone marrow mesenchymal stem cells. After inoculation, bone marrow mesenchymal stem cells permeated the porous structure of the scaffold and adhered to the scaffold. Under the role of glial cellline-derived neurotrophic factor, bone marrow mesenchymal stem cells showed neuron-like cellmorphology and cells co-cultured with the compound scaffold expressed the marker of neurons, neuron-specific enolase. Under the role of slow-release glial cellline-derived neurotrophic factor, bone marrow mesenchymal stem cells can grow wel in vitro and differentiate into neuron-like cells on the HACC/β-GP scaffold.
5.Proliferation and differentiation of mesenchymal stem cells modified with glial cell line-derived neurotrophic factor
Cheng HUANG ; Jiandong YANG ; Xinmin FENG ; Wei XU ; Yinan LI ; Haixiang XIAO ; Jiaxiang GU
Chinese Journal of Tissue Engineering Research 2013;(45):7932-7938
BACKGROUND:Exogenous neurotrophic factors or chemical induction can induce rat bone marrow mesenchymal stem cells to differentiate into neuron-like cells. However, exogenous inductors exert a short inducible action, and their chemical substances inevitably have a negative impact on cellviability to limit the application prospects of bone marrow mesenchymal stem cells to a certain extent.
OBJECTIVE:To investigate the effect of glial cellline-derived neurotrophic factor, green fluorescent protein gene transfection by adenovirus vector on biological characteristics of rat bone marrow mesenchymal stem cells, to observe the expression of glial cellline-derived neurotrophic factor and green fluorescent protein and the role of nutrition on bone marrow mesenchymal stem cells, and to explore the ability to differentiate into neuron-like cells induced by glial cellline-derived neurotrophic factor.
METHODS:The bone marrow mesenchymal stem cells at passage 3 were transfected by recombinant adenovirus (Multiplicity of infection=10, 50, 80, 100, 150, 200). The experiment had two groups according to target genes:bone marrow mesenchymal stem cells were transfected by Ad-GDNF-GFP in transfection group, and bone marrow mesenchymal stem cells were not transfected in control group. The expression of green fluorescent protein was detected by inverted fluorescence microscope. Transfection efficiency was calculated by flow cytometry. cells viability and the morphological changes of cells were compared respectively by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and inverted fluorescence microscope between the two groups. On days 5 and 10 after transfection, the expression of glial cel-derived neurotrophic factor mRNA was detected by PCR. On day 5, the expression of neuron-specific enolase was determined by immunofluorescence examination. On day 10, the expression of microtubule-associated protein 2 was identified.
RESULTS AND CONCLUSION:By the end of 12 hours after transfection, the green fluorescent protein expressed in cells, and the fluorescence intensity gradual y increased with time. When the multiplicity of infection was 100, the fluorescence intensity was strong and stable, and the transfection rate was nealy 90%on day 3 after transfection. cellviability in the transfection group was strengthened after transfection. On day 5 after transfection, bone marrow mesenchymal stem cells expressed neuron-specific enolase, and neuron-like protrusions gradual y extended. On day 10 after transfection, bone marrow mesenchymal stem cells expressed microtubule-associated protein 2 and glial cellline-derived neurotrophic factor mRNA, and exhibited neuron-like morphology and interconnected synpases. The recombinant adenovirus, Ad-GDNF-GFP, can highly transfect bone marrow mesenchymal stem cells when the multiplicity of infection is 100, and glial cellline-derived neurotrophic factor can promote the proliferation of bone marrow mesenchymal stem cells and induce bone marrow mesenchymal stem cells to differentiate into neuron-like cells.
6.Regulation of Axon Initial Segment Diameter by COUP-TFI Fine-tunes Action Potential Generation.
Xuanyuan WU ; Haixiang LI ; Jiechang HUANG ; Mengqi XU ; Cheng XIAO ; Shuijin HE
Neuroscience Bulletin 2022;38(5):505-518
The axon initial segment (AIS) is a specialized structure that controls neuronal excitability via action potential (AP) generation. Currently, AIS plasticity with regard to changes in length and location in response to neural activity has been extensively investigated, but how AIS diameter is regulated remains elusive. Here we report that COUP-TFI (chicken ovalbumin upstream promotor-transcription factor 1) is an essential regulator of AIS diameter in both developing and adult mouse neocortex. Either embryonic or adult ablation of COUP-TFI results in reduced AIS diameter and impaired AP generation. Although COUP-TFI ablations in sparse single neurons and in populations of neurons have similar impacts on AIS diameter and AP generation, they strengthen and weaken, respectively, the receiving spontaneous network in mutant neurons. In contrast, overexpression of COUP-TFI in sparse single neurons increases the AIS diameter and facilitates AP generation, but decreases the receiving spontaneous network. Our findings demonstrate that COUP-TFI is indispensable for both the expansion and maintenance of AIS diameter and that AIS diameter fine-tunes action potential generation and synaptic inputs in mammalian cortical neurons.
Action Potentials
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Animals
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Axon Initial Segment
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COUP Transcription Factor I
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DNA-Binding Proteins/physiology*
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Mammals
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Mice
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Transcription Factors