睫状神经营养因子对听觉损伤的保护作用

本研究以耳廓反射、听觉脑干诱发电位、耳蜗生物电和耳蜗铺片组织学检测为指标,观察重组人睫状神经营养因子对豚鼠庆大霉素耳毒性的防治作用。实验结果表明,睫状神经营养因子能减轻庆大霉素对耳蜗及听神经的损害,具有保护听觉功能的作用。     

Molecular phylogeny and geography of Korean medaka fish (Oryzias latipes)

The phylogeny and geography of the medaka (Oryzias latipes) populations of Korea were investigated by analyzing sequence data for the mitochondrial control region. From the 41 haplotypes including 25 Korean haplotypes detected in 64 Korean specimens and data for the Japanese and Chinese populations, phylogenetic and nested clade analyses were executed to examine the phylogeny of haplogroups and the relation of the genetic architecture of the haplotypes to the historical geography of the Korean medaka fish. The analyses suggest that there are two very distinct lineages of Korean medaka, and that these result from reproductive isolation mechanisms due to geographic barriers. The southeastern lineage has experienced recent range expansion to the western region. The northwestern lineage, sister to Chinese populations, showed evidence of internal range expansion with shared haplotypes.     

Methylation changes of lysine 9 of histone H3 during preimplantation mouse development

Immediately after fertilization, a chromatin remodeling process in the oocyte cytoplasm extracts protamine molecules from the sperm-derived DNA and loads histones onto it. We examined how the histone H3-lysine 9 methylation system is established on the remodeled sperm chromatin in mice. We found that the paternal pronucleus was not stained for dimethylated H3-K9 (H3-m2K9) during pronucleus development, while the maternal genome stained intensively. Such H3-m2K9 asymmetry between the parental pronuclei was independent of HP1b localization and, much like DNA methylation, was preserved to the two-cell stage when the nucleus appeared to be compartmentalized for H3-m2K9. A conspicuous increase in H3-m2K9 level was observed at the four-cell stage, and then the level was maintained without a visible change up to the blastocyst stage. The behavior of H3-m2K9 was very similar, but not identical, to that of 5-methylcytosine during preimplantation development, suggesting that there is some connection between methylation of histone and of DNA in early mouse development.     

1998-2013年新疆艾比湖湖面时空动态变化及其驱动机制

采用1998年9月,2002年9月,2007年9月,2011年9月以及2013年9月多期Landsat数据,利用归一化水体指数模型(NDWI)和修正归一化水体指数模型(MNDWI)提取新疆艾比湖水域面积,研究近年来艾比湖湖面的动态变化。以最大似然分类结果作为标准,验证了用NDWI和MNDWI模型提取面积的精度,得出NDWI模型所提取的湖泊面积更符合实际情况,湖泊总面积从1998年的519.26km²减少到2013年的422.73km²,缩小了18.59%,表明目前艾比湖正在退化,从而促使生态环境受到影响。对5期影像中的艾比湖湖面进行了边界的提取和叠加,利用湖泊面积动态模型研究艾比湖湖面积的动态变化,在此基础上分析了影响艾比湖湖面积变化的驱动机制,近年来随着温度的逐渐升高,降水量呈下降的趋势,加上大量的蒸发作用、径流量变化及沙尘日数等综合作用的结果,导致了艾比湖面积的缩小。多年来艾比湖流域内随着人口数量的增加、耕地面积的不断扩张、牲畜的大量增长,导致需水量逐渐增大,因此也是导致湖面面积减少的主要原因之一。开展艾比湖湖面时空动态变化及其驱动机制研究,对于干旱区湖泊来说具有重要的理论和实际意义。     

Altered connectivity pattern of hubs in default-mode network with Alzheimer's disease: an Granger causality modeling approach

Background

Evidences from normal subjects suggest that the default-mode network (DMN) has posterior cingulate cortex (PCC), medial prefrontal cortex (MPFC) and inferior parietal cortex (IPC) as its hubs; meanwhile, these DMN nodes are often found to be abnormally recruited in Alzheimer''s disease (AD) patients. The issues on how these hubs interact to each other, with the rest nodes of the DMN and the altered pattern of hubs with respect to AD, are still on going discussion for eventual final clarification.

Principal Findings

To address these issues, we investigated the causal influences between any pair of nodes within the DMN using Granger causality analysis and graph-theoretic methods on resting-state fMRI data of 12 young subjects, 16 old normal controls and 15 AD patients respectively. We found that: (1) PCC/MPFC/IPC, especially the PCC, showed the widest and distinctive causal effects on the DMN dynamics in young group; (2) the pattern of DMN hubs was abnormal in AD patients compared to old control: MPFC and IPC had obvious causal interaction disruption with other nodes; the PCC showed outstanding performance for it was the only region having causal relation with all other nodes significantly; (3) the altered relation between hubs and other DMN nodes held potential as a noninvasive biomarker of AD.

Conclusions

Our study, to the best of our knowledge, is the first to support the hub configuration of the DMN from the perspective of causal relationship, and reveal abnormal pattern of the DMN hubs in AD. Findings from young subjects provide additional evidence for the role of PCC/MPFC/IPC acting as hubs in the DMN. Compared to old control, MPFC and IPC lost their roles as hubs owing to the obvious causal interaction disruption, and PCC was preserved as the only hub showing significant causal relations with all other nodes.     

Insulin-like growth factor 2 enhances insulinogenic differentiation of human eyelid adipose stem cells via the insulin receptor

Objectives: Previously, we have isolated stem cells (HEAC) from human eyelid adipose tissue and functionally differentiated them into insulin‐secreting cells. In the present study, we examined whether insulin family members might influence insulinogenic differentiation of HEAC. Materials and methods: Following culture in differentiation media containing insulin family member or not, cells were examined for gene expression, protein expression and, particularly, insulin and C‐peptide secretion, in response to high glucose challenge. Using antibodies against the specific receptor, target receptor mediating effect of the insulin family member was investigated. Results: Insulin treatment during culture had little effect on either insulin or C‐peptide secretion from HEAC, against high glucose challenge after culture. However, insulin‐like growth factor (IGF) 1 treatment decreased both secretions, and interestingly, IGF2 greatly increased the secretions. HEAC treated with IGF2 had strong expression of Pdx1, Isl1, Pax6 and PC1/3 genes, and distinct staining after insulin and C‐peptide antibodies, and dithizone. IGF2‐enhanced insulinogenic differentiation was totally blocked by antibody against insulin receptor (IR), but not by anti‐IGF1 receptor (IGF1R). Differentiated HEAC expressed both IR and IGF1R genes, whereas they expressed neither IGF2 nor IGF2R genes. Conclusions: From these results, it is suggested that IGF1 might inhibit insulinogenic differentiation of HEAC, whereas IGF2 enhances differentiation, and that enhancement of IGF2 appeared to be mediated via IR.     

Amphotericin B aggregation inhibition with novel nanoparticles prepared with poly(epsilon-caprolactone)/poly(n,n-dimethylamino-2-ethyl methacrylate) diblock copolymer

Diblock copolymers composed of poly(epsilon-caprolactone) (PCL) and poly(N,N-dimethylamino-2-ethyl methacrylate) (PDMAEMA), or methoxy polyethylene glycol(PEG), were synthesized via a combination of ring-opening polymerization and atom-transfer radical polymerization in order to prepare polymeric nanoparticles as an antifungal drug carrier. Amphotericin B (AmB), a natural antibiotic, was incorporated into the polymeric nanoparticles. The physical properties of AmB-incorporated polymeric nanoparticles with PCL-b-PDMAEMA and PCL-b-PEG were studied in relation to morphology and particle size. In the aggregation state study, AmB-incorporated PCL-b- PDMAEMA nanoparticles exhibited a monomeric state pattern of free AmB, whereas AmB-incorporated PCL-b- PEG nanoparticles displayed an aggregated pattern. In in vitro hemolysis tests with human red blood cells, AmBincorporated PCL-b-PDMAEMA nanoparticles were seen to be 10 times less cytotoxic than free AmB (5 microgram/ml). In addition, an improved antifungal activity of AmBincorporated polymeric nanoparticles was observed through antifungal activity tests using Candida albicans, whereas polymeric nanoparticles themselves were seen not to affect activity. Finally, in vitro AmB release studies were conducted, proving the potential of AmB-incorporated PCL-b-PDMAEMA nanoparticles as a new formulation candidate for AmB.     

小麦芽依赖于DNA的RNA聚合酶Ⅱ不能转录绒毛烟斑驳病毒及其拟病毒

小麦芽经过匀浆、沉淀、高速及超速离心、透析以及DE_(52)离子交换层析等步骤,纯化小麦芽依赖于DNA的RNA聚合酶。用α-鹅膏蕈碱抑制试验,证明得到RNA聚合酶Ⅱ。用此聚合酶Ⅱ组建的体外转录体系的研究结果表明,绒毛烟斑驳病毒的拟病毒和卫星RNA(黄瓜花叶病毒相关RNA_3)都不能利用该体系进行转录,类病毒PSTV可进行转录,但转录效率明显低于小牛胸腺DNA;α-鹅膏簟碱可抑制类病毒的转录。绒毛烟斑驳病毒拟病毒和卫星RNA都不能被转录,表明他们的复制方法与类病毒不同。     

Sustainable management of grassland ecosystems for controlling Asian dusts and desertification in Asian continent and a suggestion of Eco-Village study in China

Asian dusts, yellow sand, or dust and sand storms (DSS) in Asian continent are the end products of desertification, which became a regional environmental problem being aggravated by time. It is closely related to an issue of sustainability in the region. As the desertification is caused not only by natural factors, such as the climate change, strong wind, and low precipitation, but also by rapidly increasing human activities, such as overgrazing, misuse of water resources, and irrational land use, it is urgent to make efforts to combat desertification in Asian continent including China. In this regard, it is necessary to consider socio-economic aspects as well as ecological aspects and, consequently, the project for the construction of a Demonstration Model Village for eco-environmental rehabilitation should be paid to a special attention. The authors deal with this regional issue in consideration of three Es, which are represented by ecology, economy, and environment in providing the perspectives in sound approach to the issue. As an approach to the issue of Asian dusts and desertification in Asian continent, this Eco-Village study provides one way forward.