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991.
992.
精原干细胞(spermatogonial stem cells,SSCs)作为成体干细胞的一类,既具有自我更新和分化的潜能,又可向子代传递遗传信息。阐明其增殖过程及分化特性对SSCs的进一步应用具有重要意义。小鼠SSCs的微滴培养研究显示,微滴培养技术与常规培养方法相比具有独特的优势。然而其他物种的SSCs能否实现微滴培养尚有待证实。该研究旨在利用微滴培养法建立大鼠SSCs体外培养技术。5、8、10、20、40个大鼠SSCs分别置于20此微滴中培养,用丝裂霉素处理的STO细胞作为滋养层。倒置显微镜观察记录大鼠SSCs的增殖状态。一个月后,对微滴培养的SSCs进行免疫荧光双标记染色鉴定。结果显示,一个微滴内接种5个SSCs就能实现扩增培养;培养一个月后,SSC仍然表达其特异的标记基因分子如CDH1、OCT4、PLZF、Thy1和Gfra1。体外诱导分析显示,微滴培养的大鼠SSCs具有分化为精母细胞的能力。大鼠SSCs微滴培养法的建立,为其他物种SSCs的培养提供了借鉴,也为再生医学和生命科学相关领域的研究提供了技术平台。  相似文献   
993.

Background

Evidence is increasingly accumulated about multiple roles for the β2-adrenoceptor gene in asthma. The results were inconsistent partly due to small sample sizes. To assess the association between β2-adrenoceptor gene polymorphisms and asthma risk, a meta-analysis was performed.

Methods

We comprehensively searched the PubMed, EMBASE, BIOSIS Previews databases and extracted data from all eligible articles to estimate the association between β2-adrenoceptor gene polymorphisms and asthma risk. The pooled odds ratio (OR) with 95% confidence intervals (CIs) were calculated.

Results

Thirty-seven studies involving 6648 asthma patients and 15943 controls were included in the meta-analysis. Overall, significant associations were found in allelic genetic model (OR = 1.06, 95% CI = 1.01∼1.12), recessive genetic model (OR = 1.11, 95% CI = 1.02∼1.21) for Arg/Gly16. Stratified by ethnicity and age, significant associations were also found in Asian population in allelic genetic model, recessive genetic model and addictive model. For Gln/Glu27, no significant association was found when we combined all eligible studies. Age stratification showed significant associations in adults in allelic genetic model and recessive genetic model, but no significant association was found among Asians and Caucasians in ethnicity stratification.

Conclusions

This meta-analysis implied that the β2-adrenoceptor Arg/Gly16 polymorphism was likely to contribute to asthma risk in Asian population. Gln/Glu27 polymorphism might be a contributor to asthma susceptibility for adults.  相似文献   
994.
AimWe performed a comprehensive meta-analysis to determine the association between P2X7 -762T/C polymorphism and pulmonary tuberculosis susceptibility.MethodologyBased on comprehensive searches of the PubMed, SCI, Elsevier, China National Knowledge Infrastructure (CNKI) and Wanfang Database, we identified eligible studies about the association between P2X7 -762T/C polymorphism and pulmonary tuberculosis risk. Pooled odds ratio (ORs) and 95% confidence intervals (95%CIs) were calculated in random-effects model.ResultsA total of 2207 tuberculosis cases and 2220 controls in 8 case-control studies were included in this meta-analysis. Allele model (C vs. T: p = 0.15; OR = 0.83, 95% CI = 0.65–1.07), homozygous model (CC vs. TT: p = 0.23; OR = 0.73, 95% CI = 0.44 to 1.22), and heterozygous model (CT vs. TT: p = 0.57; OR = 0.92, 95% CI = 0.68 to 1.24) did not show increased risk of developing pulmonary tuberculosis. Similarly, dominant model (CC+CT vs. TT: p = 0.32; OR = 0.84, 95% CI = 0.59 to 1.19) and recessive model (CC vs. CT+TT: p = 0.08; OR = 0.77, 95% CI = 0.57 to 1.04) failed to show increased risk of developing pulmonary tuberculosis. Subgroup analysis by ethnicity did not detect any significant association between P2X7–762T/C polymorphism and pulmonary tuberculosis susceptibility.ConclusionsP2X7 -762T/C gene polymorphism is not associated with pulmonary tuberculosis susceptibility.  相似文献   
995.

Aims

Accurate computed tomography (CT)-based reconstruction of coronary morphometry (diameters, length, bifurcation angles) is important for construction of patient-specific models to aid diagnosis and therapy. The objective of this study is to validate the accuracy of patient coronary artery lumen area obtained from CT images based on intravascular ultrasound (IVUS).

Methods and Results

Morphometric data of 5 patient CT scans with 11 arteries from IVUS were reconstructed including the lumen cross sectional area (CSA), diameter and length. The volumetric data from CT images were analyzed at sub-pixel accuracy to obtain accurate vessel center lines and CSA. A new center line extraction approach was used where an initial estimated skeleton in discrete value was obtained using a traditional thinning algorithm. The CSA was determined directly without any circular shape assumptions to provide accurate reconstruction of stenosis. The root-mean-square error (RMSE) for CSA and diameter were 16.2% and 9.5% respectively.

Conclusions

The image segmentation and CSA extraction algorithm for reconstruction of coronary arteries proved to be accurate for determination of vessel lumen area. This approach provides fundamental morphometric data for patient-specific models to diagnose and treat coronary artery disease.  相似文献   
996.
采用测定生物量与精油提取相结合的方法来研究确定木香薷的最佳采收期。结果表明:霍山地区木香薷的最佳采收期在8月中旬。木香薷生物量的增长在前期主要表现为当年生小枝数的增加,而后期表现为当年生小枝重量的增加。从5月12日到8月17日,每100 g干重的当年生枝产精油量逐渐增加,而8月17日之后精油产量逐渐下降,以8月7日为最高达到1.62 g,得率为1.62%。  相似文献   
997.
Accurate mitosis requires the chromosomal passenger protein complex (CPC) containing Aurora B kinase, borealin, INCENP, and survivin, which orchestrates chromosome dynamics. However, the chromatin factors that specify the CPC to the centromere remain elusive. Here we show that borealin interacts directly with heterochromatin protein 1α (HP1α) and that this interaction is mediated by an evolutionarily conserved PXVXL motif in the C-terminal borealin with the chromo shadow domain of HP1α. This borealin-HP1α interaction recruits the CPC to the centromere and governs an activation of Aurora B kinase judged by phosphorylation of Ser-7 in CENP-A, a substrate of Aurora B. Consistently, modulation of the motif PXVXL leads to defects in CPC centromere targeting and aberrant Aurora B activity. On the other hand, the localization of the CPC in the midzone is independent of the borealin-HP1α interaction, demonstrating the spatial requirement of HP1α in CPC localization to the centromere. These findings reveal a previously unrecognized but direct link between HP1α and CPC localization in the centromere and illustrate the critical role of borealin-HP1α interaction in orchestrating an accurate cell division.  相似文献   
998.
【目的】为了阐明乳酸乳球菌乳酸亚种KLDS4.0325的生理及代谢机制,并对其重要功能基因进行挖掘,我们对菌株KLDS4.0325的全基因组序列进行测定和基因组图谱的绘制,并利用生物软件和数据库完成对序列的注释及相关功能性分析。【方法】在菌株序列完成测序、组装和注释后,根据序列信息进行全基因组图谱的绘制,并对菌株的蛋白质水解系统、氨基酸来源的风味形成途径和B-族维生素合成途径进行了比较基因组分析,并对细菌素合成基因组和冷应激蛋白基因进行了预测。【结果】菌株KLDS4.0325基因组全长2589250 bp,G+C含量为35.4%,共预测出2662个开放阅读框,其中1310个具有潜在的生物学功能。菌株可以有效的对细胞外蛋白质进行有效的水解,具有潜在的降低苦味肽以及产生一系列能够抑制血管紧张素转化酶活性的活性肽。在转氨途径方面,菌株KLDS4.0325具有较为完成的酶系统,可以催化相关氨基酸转化为风味物质。在菌株KLDS4.0325的基因组中,我们发现了较多编码糖转运、代谢以及L-乳酸合成的基因。关于叶酸和核黄素合成途径的编码基因在菌株KLDS4.0325的基因组中也较为完整。此外,我们在菌株KLDS4.0325的基因组中预测出了一个关于乳球菌素的基因簇和两个冷应激蛋白Csp D和csp E的编码基因。【结论】这些编码菌株显著特性基因的存在为菌株KLDS4.0325能够进行工业发酵提供了理论基础,并为其进一步研究提供了方向。  相似文献   
999.
Deer antlers mature rapidly in 60 days, and subsequently shed in 5 days with rapid ossification. During this procedure, the function of deer antlers changes significantly. Therefore, the profiling of antler proteome is helpful to discover important growing and shedding regulation proteins, which might be of great significance for studying development and regeneration. In this study, a parallel protein extraction strategy was developed to extract proteins from antlers of red deer with five different lysis solutions, followed by shotgun proteomic analysis by microflow reversed-phase liquid chromatography/electrospray ionization/tandem mass spectrometry (μRPLC-ESI-MS/MS) with a 30 cm-long serially coupled microcolumn. Our experimental results showed that the identified proteins extracted by five kinds of lysis solution were complementary to each other. In total, 416 unique proteins were identified, with relative molecular masses from 2000 to 600,000, and isoelectric points from 3.84 to 11.57. All these results demonstrate that the combination of parallel protein extraction strategy and μRPLC-ESI-MS/MS analysis with serially coupled long microcolumns might be of great significance for comprehensive proteomic research of deer antler.  相似文献   
1000.
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