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To date, various types of cells for seeding regenerative scaffolds have been used for bone tissue engineering. Among seed cells, the mesenchymal stem cells derived from human umbilical cord Wharton’s jelly (hUCMSCs) represent a promising candidate and hold potential for bone tissue engineering due to the the lack of ethical controversies, accessibility, sourced by non-invasive procedures for donors, a reduced risk of contamination, osteogenic differentiation capacities, and higher immunomodulatory capacity. However, the current culture methods are somewhat complicated and inefficient and often fail to make the best use of the umbilical cord (UC) tissues. Moreover, these culture processes cannot be performed on a large scale and under strict quality control. As a result, only a small quantity of cells can be harvested using the current culture methods. To solve these problems, we designed and evaluated an UC Wharton’s jelly repeated culture device. Using this device, hUCMSCs were obtained from the repeated cultures and their quantities and biological characteristics were compared. We found that using our culture device, which retained all tissue blocks on the bottom of the dish, the total number of obtained cells increased 15–20 times, and the time required for the primary passage was reduced. Moreover, cells harvested from the repeated cultures exhibited no significant difference in their immunophenotype, potential for multilineage differentiation, or proliferative, osteoinductive capacities, and final osteogenesis. The application of the repeated culture frame (RCF) not only made full use of the Wharton’s jelly but also simplified and specified the culture process, and thus, the culture efficiency was significantly improved. In summary, abundant hUCMSCs of dependable quality can be acquired using the RCF.  相似文献   
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Flowering time regulation is one of the most important processes in the whole life of flowering plants and FLOWERING LOCUS C (FLC) is a central repressor of flowering time. However, whether metabolic acetate level affects flowering time is unknown. Here we report that ALDEHYDE DEHYDROGENASE ALDH3F1 plays essential roles in floral transition via FLC‐dependent pathway. In the aldh3f1‐1 mutant, the flowering time was significant earlier than Col‐0 and the FLC expression level was reduced. ALDH3F1 had aldehyde dehydrogenase activity to affect the acetate level in plants, and the amino acids of E214 and C252 are essential for its catalytic activity. Moreover, aldh3f1 mutation reduced acetate level and the total acetylation on histone H3. The H3K9Ac level on FLC locus was decreased in aldh3f1‐1, which reduced FLC expression. Expression of ALDH3F1 could rescue the decreased H3K9Ac level on FLC, FLC expression and also the early‐flowering phenotype of aldh3f1‐1, however ALDH3F1E214A or ALDH3F1C252A could not. Our findings demonstrate that ALDH3F1 participates in flowering time regulation through modulating the supply of acetate for acetyl‐CoA, which functions as histone acetylation donor to modulate H3K9Ac on FLC locus.  相似文献   
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BackgroundCerebral palsy (CP) is a group of non-progressive motor impairment and permanent disorders causing limitation of activity and abnormal posture. It may be caused by infection (such as chorioamnionitis), asphyxia or multiple genetic factors. The Interleukin 6 gene (IL6) was suggested to be involved in the susceptibilities to CP risk as a kind of proinflammatory cytokine.ObjectiveTo explore the genetic association between the polymorphisms of the IL6 gene and CP in the Chinese population.MethodsA total of 542 CP patients and 483 healthy control children were recruited in this study to detect five single nucleotide polymorphisms (rs1800796, rs2069837, rs2066992, rs2069840, and rs10242595) in the IL6 locus. Genotyping of SNPs was performed by the MassArray platform-based genotyping approach. The SHEsis program was applied to analyze the genotyping data.ResultsOf the five selected SNPs, no significant allelic and genotypic association was found between CP patients and controls. However, subgroup analysis found significant differences in allele frequencies between spastic tetraplegia in males compared with controls at rs1800796 (OR = 1.39, P = 0.033, P = 0.099 after SNPSpD correction) and rs2069837 (OR = 1.58, P = 0.012, P = 0.035 after SNPSpD correction). The frequencies of the C allele of rs1800796 and the A allele of rs2069837 were greater in males with spastic tetraplegia than in the controls. The two SNPs haplotype rs1800796 (G) – rs2069837 (G) were also associated with a decreased risk of spastic tetraplegia in males (OR = 0.619, P = 0.009, P = 0.027 after Bonferroni correction).ConclusionGenetic variation of the IL6 gene may influence susceptibility to spastic tetraplegia in males and its role in cerebral palsy deserves further evaluation in a large-scale and well-designed study.  相似文献   
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25名运动员在相同的时间里随3种不同类型的负荷和不同的时间里承受相同的负荷,测定负荷后血浆TCA循环产物,FFA组成和尿液尿素氮,尿肌酐,游离氨基酸组分含量。结果表明:同一时间里采用运动量相近但类型不同的负荷,会产生不同的生理效应,同一负荷内容安排在下午比安排在早晨或上午更容易导致人体内蛋白质分解代谢加强;耐力负荷以早晨训练对TCA循环和FFA及其组分影响较大;下午训练利于发展速度,力量等项目的素  相似文献   
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特定条件下,利用热酸解处理方法,可从碳酸盐岩中分析处理出完整,表面干净的介形类化石,本文简述该方法的具体操作过程及原理。  相似文献   
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Background

Angiogenesis plays an important role in a wide range of physiological processes, and many diseases are associated with the dysregulation of angiogenesis. Radix Astragali is a Chinese medicinal herb commonly used for treating cardiovascular disorders and has been shown to possess angiogenic effect in previous studies but its active constituent and underlying mechanism remain unclear. The present study investigates the angiogenic effects of calycosin, a major isoflavonoid isolated from Radix Astragali, in vitro and in vivo.

Methodology

Tg(fli1:EGFP) and Tg(fli1:nEGFP) transgenic zebrafish embryos were treated with different concentrations of calycosin (10, 30, 100 µM) from 72 hpf to 96 hpf prior morphological observation and angiogenesis phenotypes assessment. Zebrafish embryos were exposed to calycosin (10, 100 µM) from 72 hpf to 78 hpf before gene-expression analysis. The effects of VEGFR tyrosine kinase inhibitor on calycosin-induced angiogenesis were studied using 72 hpf Tg(fli1:EGFP) and Tg(fli1:nEGFP) zebrafish embryos. The pro-angiogenic effects of calycosin were compared with raloxifene and tamoxifen in 72 hpf Tg(fli1:EGFP) zebrafish embryos. The binding affinities of calycosin to estrogen receptors (ERs) were evaluated by cell-free and cell-based estrogen receptor binding assays. Human umbilical vein endothelial cell cultures (HUVEC) were pretreated with different concentrations of calycosin (3, 10, 30, 100 µM) for 48 h then tested for cell viability and tube formation. The role of MAPK signaling in calycosin-induced angiogenesis was evaluated using western blotting.

Conclusion

Calycosin was shown to induce angiogenesis in human umbilical vein endothelial cell cultures (HUVEC) in vitro and zebrafish embryos in vivo via the up-regulation of vascular endothelial growth factor (VEGF), VEGFR1 and VEGFR2 mRNA expression. It was demonstrated that calycosin acted similar to other selective estrogen receptor modulators (SERMs), such as raloxifene and tamoxifen, by displaying selective potency and affinity to estrogen receptors ERα and ERβ. Our results further indicated that calycosin promotes angiogenesis via activation of MAPK with the involvement of ERK1/2 and ER. Together, this study revealed, for the first time, that calycosin acts as a selective estrogen receptor modulator (SERM) to promote angiogenesis, at least in part through VEGF-VEGFR2 and MAPK signaling pathways.  相似文献   
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