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101.
人脐血间充质干细胞分离培养方法的优化 总被引:2,自引:1,他引:2
目的探讨人脐血间充质干细胞(MSCs)体外培养纯化的最佳方法,为脐血MSCs在临床的广泛应用奠定基础。方法无菌条件下采集足月分娩和早产儿脐血,密度梯度离心法分离脐血单个核细胞,比较胎龄、不同培养基、接种密度、首次换液时间对脐血MSCs原代培养过程的影响,通过免疫荧光方法检测表面标记物的表达情况,观察脐血MSCs的生物学特性。结果足月分娩脐血,采用MesencultTM培养基,以5×106/cm2的密度接种,首次换液时间为7d时,脐血MSCs原代培养成功率较高。相同培养条件下,早产儿脐血培养成功率高于足月分娩脐血。人脐血MSCs强表达CD29、CD44和CD90,不表达造血干细胞表面标志CD34。结论优化筛选到一种合适的人脐血MSCs培养纯化条件。 相似文献
102.
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104.
Electron microscopic examination of the orexin immunoreactivity in the dorsal raphe nucleus 总被引:1,自引:0,他引:1
The ultrastructure and the synaptic relationships of the orexin-A-like immunoreactive fibers in the dorsal raphe nucleus were examined with an immunoelectron microscopic method. At the electron microscopic level, most of the immunoreactive fibers, a varicosity appearance at the light microscopic level, were found as axon terminals. The large dense-cored vesicles contained in the immunoreactive axon terminals were the most intensely immunostained organellae. These axon terminals were often found to make synapses. While the axo-dendritic synapses were usually asymmetric in appearance, the axo-somatic synapses were symmetric. Orexin-A-like immunoreactive processes with no synaptic vesicles were also found. These processes often received asymmetric synapses. With less frequency, the synapses were found between the orexin-like immunoreactive processes. The results suggest that the orexin peptides are stored in the large dense-cored vesicles; the orexin-containing fibers may have influences on the physiological activities of the dorsal raphe nucleus through direct synaptic relationships. 相似文献
105.
Guan S Ma S Zhu Y Ge R Wang Q Wang JH 《Biochemical and biophysical research communications》2006,345(1):175-180
Cerebellum is involved in the motion coordination and working memory, to which the programming of sequential spikes at Purkinje cells is essential. It is not clear about the intrinsic mechanisms underlying spike capacity and timing precision as well as their postnatal maturation. We investigated the programming and intrinsic property of sequential spikes at Purkinje neurons during postnatal development by whole-cell recording in cerebellar slices. Cerebellar Purkinje neurons demonstrate the increasing of spike capacity and timing precision, as well as the lowering of refractory periods and threshold potentials during the postnatal maturation. In addition, the correlation between spike parameters and intrinsic properties converts to be more linear. This postnatal plasticity of neuronal intrinsic properties improves the timing precision and capacity of spike programming at cerebellar Purkinje neurons. 相似文献
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107.
Hydrobiologia - Lake Malaŵi cichlids have evolved rapidly, extensively, and in some cases iteratively to fill an array of ecological niches; however, neither species richness nor trophic... 相似文献
108.
This article examines the location-allocation of emergency service facilities as a research subject. The research presents the setup of the single allocation set covering location-allocation models for emergency service facilities under strong time constraints, in view of the shortage of hub & spoke network bypass. The article also presents an extension to the single allocation set covering location-allocation model (SASCP) and the SASCP model with bypass constraints (γ-SASCP) for emergency service facilities under large-scale emergency requirements. For the two models, an improved genetic algorithm was designed and the two models were respectively solved, with the effectiveness of the algorithm verified by a specific example. The impacts of change of parameters such as time discount rate, maximum time constraints, and bypass ratio on the model's results are compared and analyzed, based on solved results by the specific example. 相似文献
109.
Yi Liu Michael J. Trnka Shenheng Guan Doyoung Kwon Do-Hyung Kim J.-J. Chen Peter A. Greer A. L. Burlingame Maria Almira Correia 《Molecular & cellular proteomics : MCP》2020,19(12):1968-1986
Highlights
- •Liver Mallory-Denk-Body inducers elicited an IκBα-loss and NF-κB-activation.
- •IκBα-loss was due to its sequestration into insoluble cytoplasmic aggregates.
- •Four proteomic approaches identified 10 IκBα-interacting/aggregating proteins.
- •Nup153/RanBP2-aggregation prevented IκBα nuclear entry for ending NF-κB-activation.
110.
Andrea J. Hartlerode Yinghua Guan Anbazhagan Rajendran Kiyoe Ura Gunnar Schotta Anyong Xie Jagesh V. Shah Ralph Scully 《PloS one》2012,7(11)
Recruitment of 53BP1 to chromatin flanking double strand breaks (DSBs) requires γH2AX/MDC1/RNF8-dependent ubiquitination of chromatin and interaction of 53BP1 with histone H4 methylated on lysine 20 (H4K20me). Several histone methyltransferases have been implicated in 53BP1 recruitment, but their quantitative contributions to the 53BP1 response are unclear. We have developed a multi-photon laser (MPL) system to target DSBs to subfemtoliter nuclear volumes and used this to mathematically model DSB response kinetics of MDC1 and of 53BP1. In contrast to MDC1, which revealed first order kinetics, the 53BP1 MPL-DSB response is best fitted by a Gompertz growth function. The 53BP1 MPL response shows the expected dependency on MDC1 and RNF8. We determined the impact of altered H4K20 methylation on 53BP1 MPL response kinetics in mouse embryonic fibroblasts (MEFs) lacking key H4K20 histone methyltransferases. This revealed no major requirement for the known H4K20 dimethylases Suv4-20h1 and Suv4-20h2 in 53BP1 recruitment or DSB repair function, but a key role for the H4K20 monomethylase, PR-SET7. The histone methyltransferase MMSET/WHSC1 has recently been implicated in 53BP1 DSB recruitment. We found that WHSC1 homozygous mutant MEFs reveal an alteration in balance of H4K20 methylation patterns; however, 53BP1 DSB responses in these cells appear normal. 相似文献