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BACKGROUND:Different structures of matrix models, such as grating, holes and pil ars make different effects on the differentiation of neural stem cel s. OBJECTIVE:To explore the effects of the diameter and spacing, known as physical signals of micro pil ars on neural stem cel differentiation. METHODS:Micro pil ars with different diameters and spacing, both of which had four dimensions of 2.5, 5, 10 and 20μm, were fabricated on silicon substrates by photolithographic method. Purified primary neural stem cel s were incubated on the each micro pil ar for 7 days in vitro. Then the differentiation of neural stem cel s into neuron-like cel s was observed using immunofluorescence staining and quantitative real-time PCR. RESULTS AND CONCLUSION:When the diameters of the micro pil ars were constant and the spacing of micro pil ars varied in the range of 2.5-10μm, the differentiation rate of neural stem cel s increased with the spacing increase. When the spacing was invariable and the diameters changed in the range of 2.5-20μm, the differentiation rate of neural stem cel s declined with the diameter increase. Especial y, the micro pil ars with 2.5μm diameter and 10μm spacing significantly promoted the differentiation of neural stem cel s into neuron-like cel s. These results show that specific micro pil ars with smal diameters and large spacing facilitate the differentiation of neural stem cel s, thus providing guidance for developing tissue-engineered scaffolds.
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Objective To investigate the expression of Toll-like receptor 4 (TLR4),and explore its relationship with neurological function after fluid percussion brain injury in rats.Methods 56 adult rats were randomly divided into traumatic brain injury group(TBI group,n=48) and sham operation group(SO group,n=8).The experimental models were established.The water content of edematous brain and the expression of TLR4 were measured with dry-wet measure,immunohistochemistry and Western Blot at 1 h,6 h,12 h,24 h,3 d,7 d after shock respectively.Results Compared with SO group,neuronal function score decreased in TBI group from 6 h(3.86±0.42),reached to the lowest level at 24 h(2.65±0.32),and gradually rose at 3rd day (3.25±0.17).TLR4 immunoreactive expression increased from 6 h,reached its maxmum at 24 h,lasted to 3rd day,and then began to drop at 7th day.The linear regression analysis indicated that expression of TLR4 had negative correlation with change of neuronal function score (r 1 =-0.824,r w =-0.867,P＜0.05).Conclusion TLR4 expression is upregulated following fluid percussion injury in rats and involved in neurological function impairment by inducing secondary inflammatory brain injury.
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Objective: To compare the efifcacy and safety of circumferential pulmonary vein antecourt isolation (CPVAI) ablation and stepwise linear (SL) ablation in treating the patients with atrial ifbrillation (AF) Methods: A total of 136 AF patients with catheter ablation under EnSite 3000 guidance in our hospital were retrospectively summarized. The patients included 93 paroxysmal AF and 43 persistent AF and divided into 4 groups. Paroxysmal AF with CPVAI ablation,n=45, Paroxysmal AF with SL ablation,n=48 and persistent AF with CPVAI ablation, n=18, persistent AF with SL ablation,n=25. The differences of left atrium diameter, ablation time, X-ray exposure time, the success rate and complication were compared among different groups. Results: For 12 months follow-up study, the success rate and complication were similar between 2 ablation methods for treating both Paroxysmal AF and persistent AF patients. For Paroxysmal AF patients, both ablation methods could effectively reduce left atrium diameter,P<0.01. The SL ablation had less procedural time than CPVAI ablation,P<0.01, while the X-ray exposure time was similar between 2 ablation methods. Conclusion: Both CPVAI and SL ablation methods were effective and safe for treating AF patients.