FTIR-ATR结合膜富集技术测定中药材地龙中微量铜的含量

目的 利用傅里叶变换-衰减全反射红外光谱(FTIR-ATR)结合膜富集技术,建立中药材地龙中微量铜质量分数的快速、经济的测定方法.方法 首先,对30批校正集样品进行湿法消解,利用铜与金属络合剂1-(2-吡啶偶氮)-2-萘酚(PAN)发生络合反应,优化各种反应条件,包括pH 、PAN用量、反应时间.再将络合物抽滤富集在微孔滤膜上,采集其FTIR-ATR光谱,经9点平滑、一阶导数9点平滑等预处理后,利用随机森林回归算法建立其铜质量分数的定量校正模型.校正集按3∶1随机分配为训练集和测试集,对模型进行参数优化和评价.利用优化后模型预测广东、广西和福建3个产地地龙样品中铜的质量分数,并与ICP-MS测定结果进行比较.结果 最优模型预测3个产地地龙样品的质量分数在5.85～6.98 mg/kg之间,与ICP-MS分析结果相比,相对误差均小于20％.结论 本方法利用膜富集技术提高了FTIR-ATR的检测灵敏度,为中药材重金属元素的定量分析提供了一种新方法.     

富氧环境对急进高原人体生理指标和工作效能的影响

目的探讨基于分子筛技术在高原地区建立的富氧环境对人体生理指标,包括心率(HR)、血氧饱和度(SpO2)以及工作效能的影响。方法在海拔3 680 m的高原环境中,嘱受试者在普通帐篷内休息8 h,用Philips MP20多参数检测仪监测40名受试对象在静息状态下的HR与SpO2,与此同时,检测受试者的工作效能(主要包括数字运算和图案匹配两个项目)得分。之后,利用分子筛式制氧机向半密封式帐篷内供氧,建立氧浓度为27%的富氧环境,让受试者在富氧环境中休息8 h后,静息状态下监测40名受试对象HR,SpO2以及工作效能的测量得分。对比两次测量结果,从而确定高原富氧环境对急进高原人HR,SpO2以及工作效能的影响。结果在高原富氧环境中休息后,受试者SpO2以及工作效能的测量得分显著增高(P<0.05),HR显著降低(P<0.05)。结论高原富氧环境能有效提高人体的SpO2以及工作效能,降低急进高原人群的HR,促进急进高原人群的高原习服过程。     

Cognitive impairment and cardiovascular disease: So near,so far

In the spectrum of cognitive impairment, ranging from “pure” vascular dementia to Alzheimer's disease (AD), clinical interest has recently expanded from the brain to also include the vessels, shifting the pathophysiological focus from the leaves of synaptic dysfunction to the sap of cerebral microcirculation and the roots of cardiovascular function. From a diagnostic viewpoint, a thorough clinical evaluation of individuals presenting cognitive impairment might systematically include the assessment of the major cardiovascular rings of the chain linking regional perfusion to brain function: 1) lung (with assessment of asthma, chronic obstructive pulmonary disease, obstructive sleep apnea syndrome); 2) heart function (with clinical examination and echocardiography) and cardiovascular risk factors; 3) orthostatic hypotension (with medical history and measurement of heart rate and blood pressure in supine and upright positions); 4) aorta and large artery stiffness (with assessment of pulse wave velocity); 5) large cerebro-vascular vessel status (with neuroimaging techniques); 6) assessment of microcirculation (with cerebrovascular reactivity testing with transcranial Doppler sonography or MRI perfusion imaging); and 7) assessment of venous cerebral circulation. The apparent difference in approaches to “brain” and “vascular” environmental enrichment with physical, cognitive and sensorial training is conceptually identical to that of a constant gardener caring for an unhealthy tree, watering the leaves (“train the brain”) or simply the roots (“mind the vessel”). The therapeutic difference probably consists in the amount and quality of water added to the tree, rather than by where one pours it, with either a top-down (leaves to roots) or bottom-up (roots to leaves) approach.     

成球培养法富集胰腺癌肿瘤干细胞的研究

目的 研究成球培养法培养胰腺癌肿瘤干细胞的可行性。方法 通过细胞成球培养体系富集胰腺癌肿瘤干细胞并进行培养,流式细胞术检测分析干细胞的表型特征。结果 光镜下,成球培养细胞形态发生明显变化,细胞由贴壁时的多边形变成圆形,并形成肿瘤细胞微球。流式细胞仪检测发现,与普通细胞培养相比,成球培养体系富集的胰腺癌肿瘤干细胞干性相关基因CD24、CD44共表达水平明显升高。结论 利用成球培养法能够富集得到CD24、CD44高表达的胰腺癌肿瘤干细胞。     

Anterior thalamic lesions reduce spine density in both hippocampal CA1 and retrosplenial cortex,but enrichment rescues CA1 spines only

Injury to the anterior thalamic nuclei (ATN) may affect both hippocampus and retrosplenial cortex thus explaining some parallels between diencephalic and medial temporal lobe amnesias. We found that standard‐housed rats with ATN lesions, compared with standard‐housed controls, showed reduced spine density in hippocampal CA1 neurons (basal dendrites, ?11.2%; apical dendrites, ?9.6%) and in retrospenial granular b cortex (Rgb) neurons (apical dendrites, ?20.1%) together with spatial memory deficits on cross maze and radial‐arm maze tasks. Additional rats with ATN lesions were also shown to display a severe deficit on spatial working memory in the cross‐maze, but subsequent enriched housing ameliorated their performance on both this task and the radial‐arm maze. These enriched rats with ATN lesions also showed recovery of both basal and apical CA1 spine density to levels comparable to that of the standard‐housed controls, but no recovery of Rgb spine density. Inspection of spine types in the CA1 neurons showed that ATN lesions reduced the density of thin spines and mushroom spines, but not stubby spines; while enrichment promoted recovery of thin spines. Comparison with enriched rats that received pseudo‐training, which provided comparable task‐related experience, but no explicit spatial memory training, suggested that basal CA1 spine density in particular was associated with spatial learning and memory performance. Distal pathology in terms of reduced integrity of hippocampal and retrosplenial microstructure provides clear support for the influence of the ATN lesions on the extended hippocampal system. The reversal by postoperative enrichment of this deficit in the hippocampus but not the retrosplenial cortex may indicate region‐specific mechanisms of recovery after ATN injury. © 2014 Wiley Periodicals, Inc.     

Investigation of microRNA expression signatures in HCC via microRNA Gene Chip and bioinformatics analysis

BackgroundDysregulation of miRNAs is closely involved with hepatocellular carcinoma (HCC) progression, oncogenesis and signalling pathways. The aim of this study was to investigate differences in expression of miRNAs in HCC tissue in comparison to healthy liver tissue, as well as to explore the key miRNA-targeted genes.MethodsGene Chip microarray analysis was used to analyse differentially expressed miRNAs (DEMs) in tissues, and qRT-PCR was performed to validate the top 9 downregulated miRNAs. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed for target genes using the DAVID database. A protein-protein interaction (PPI) network of the target genes was created by STRING and visualised using Cytoscape. Three online miRNA databases were utilised to aid in the prediction of genes targeted by the top 10 significantly altered DEMs.ResultsIn total, 153 upregulated and 206 downregulated miRNAs were identified in HCC tissue. The genes targeted by the top 10 increased and decreased miRNAs were 6 and 1060, respectively. Moreover, FOXO1 was projected to be regulated by all twenty miRNAs. A PPI network was constructed that consisted of 956 nodes and 1298 edges. Four significant modules, consisting of 66 hub genes, were detected from the PPI system via MCODE. Functional enrichment demonstrated that miRNAs have a vital function in cancer development and advancement.ConclusionIn summary, our study identified DEMs in HCC tissue, major target genes and possible molecular mechanisms that underlie HCC, providing novel insights for treatment approaches.     

Xdrop: Targeted sequencing of long DNA molecules from low input samples using droplet sorting

Long‐read sequencing can resolve regions of the genome that are inaccessible to short reads, and therefore are ideal for genome‐gap closure, solving structural rearrangements and sequencing through repetitive elements. Here we introduce the Xdrop technology: a novel microfluidic‐based system that allows for targeted enrichment of long DNA molecules starting from only a few nanograms of DNA. Xdrop is based on the isolation of long DNA fragments in millions of droplets, where the droplets containing a target sequence of interest are fluorescently labeled and sorted using flow cytometry. The final product from the Xdrop procedure is an enriched population of long DNA molecules that can be investigated by sequencing. To demonstrate the capability of Xdrop, we performed enrichment of the human papilloma virus 18 integrated into the genome of human HeLa cells. Analysis of the sequencing reads resolved three HPV18‐chr8 integrations at base‐pair resolution, and the captured fragments extended up to 30 kb into the human genome at the integration sites. Further, we enriched the complete TP53 locus in a leukemia cell line and could successfully phase coexisting mutations using PacBio sequencing. In summary, our results show that Xdrop is an efficient enrichment technology for studying complex genomic regions.     

Anaglyph of Retinal Stem Cells And Developing Axons: Selective Volume Enhancement In Microscopy Images

Retinal stem cell culture has become a powerful research tool, but it requires reliable methods to obtain high‐quality images of living and fixed cells. This study describes a procedure for using phase contrast microscopy to obtain three‐dimensional (3‐D) images for the study of living cells by photographing a living cell in a culture dish from bottom to top, as well as a procedure to increase the quality of scanning electron micrographs and laser confocal images. The procedure may also be used to photograph clusters of neural stem cells, and retinal explants with vigorous axonal growth. In the case of scanning electron microscopy and laser confocal images, a Gaussian procedure is applied to the original images. The methodology allows for the creation of anaglyphs and video reconstructions, and provides high‐quality images for characterizing living cells or tissues, fixed cells or tissues, or organs observed with scanning electron and laser confocal microscopy. Its greatest advantage is that it is easy to obtain good results without expensive equipment. The procedure is fast, precise, simple, and offers a strategic tool for obtaining 3‐D reconstructions of cells and axons suitable for easily determining the orientation and polarity of a specimen. It also enables video reconstructions to be created, even of specimens parallel to the plastic base of a tissue culture dish, It is also helpful for studying the distribution and organization of living cells in a culture, as it provides the same powerful information as optical tomography, which most confocal microscopes cannot do on sterile living cells. Anat Rec, 297:770–780, 2014. © 2014 Wiley Periodicals, Inc.