金融集聚向扩散转化动因及机理研究

通过将大量金融资源汇集到金融中心区域,金融集聚达到促进经济发展的目的,但任何特定的地理范围都有其资源容量的极限。随着金融资源的演进,金融集聚逐渐转化为金融扩散。本文从金融集聚角度对金融扩散现象解读,发现金融扩散是在多种动因的作用下形成的,包括外围地区资本充足带来的低成本、松散竞争带来的高收益,以及信息和资源溢出的效应。由于各种动因并不是单独发挥作用,彼此之间相互影响与交叉,最终可归纳为三条转化率:基于成本的密度规律、基于收益率的引力规律和基于辐射作用的辐射规律。

EXPRESSION AND LOCALIZATION OF SMAD4 PROTEIN IN RAT TESTIS DURING THE POSTNATAL DEVELOPMENT

Objective.To study expression and localiza tion of Smad4protein,the common-mediator Smad,which is one of intracellular signaling molecules of transforming growth factor-afamily,in rat t estis during postnatal development.Methods.In this study,whole testes were co llected from S.D rats aged3days,7days,14days and28days,and adult respe ctively.We examined the cellular localization and developmental change of Smad 4in rat testis by immunohistochemical ABC method with glucose oxidase-DAB-nic kel enhancement technique;the quantitative analysis of the immunostaining by t he image analysis system;the Smads pro-teins coexistence in the adult rat test is by the double immune staining for CD14-Smad4and Smad2-Smad4;the prote in expression of Smad during rat testicular development by means of Western blo ts.Results.The protein of Smad4was present in rats from3days of age to adul thood,and the im-munolocalization was exclusively localized to the cytoplasm o f Leydig cells with negative nuclei in the in-terstitial tissue at any time po int.No expression was detected in germ cells.The result of image and sta-tis tical analysis showed that generally,there was a tendency that the expression o f Smad4in the testes increased gradually with the rats developing maturation.C onclusion.Our data provide direct evidence for the molecular mechanism of TGF-aaction in rat testes during postnatal development and spermatogenesis of ra ts.

TRANSFORMING GROWTH FACTOR-β1 AND SMAD4 SIGNALING PATHWAY DOWN-REGULATES RENAL EXTRACELLULAR MATRIX DEGRADATION IN DIABETIC RATS

Objective To investigate the role of transforming growth factor-131 （TGF-β1）/Smad4 pathway in development of renal fibrosis in streptozotocin （STZ）-induced diabetic nephropathy （DN） rats and explore its possible mechanism. Methods Male Wistar rats weighing 180-220 g were divided into 5 groups： group A （ normal control）, group B [ diabetes mellitus （DM） 2 weeks ], group C （ DM 4 weeks）, group D （ DM 8 weeks）, and group E （ DM 16 weeks）. Except for the normal control group, other groups were induced DM by single injection of STZ （55 mg/kg） respectively. Blood glucose level, serum creatinine, and 24-hour urine protein were examined. Expressions of TGF-β1 and Smad4 protein and mRNA in kidney were detected using immunohistochemical technique, Western blot, and real-time PCR. mRNA expressions of stromelysin-1 （ MMP-3 ）, tissue inhibitor of metalloproteinase-1 （ TIMP-1 ）, and collagen Ⅲ in kidney were also detected by real-time PCR. Results The levels of blood glucose, serum creatinine, and 24-hour urine protein in rats of group B, C, D, and E were higher than those of the control group. With the progression of renal fibrosis, the expressions of TGF-β1 and Smad4 protein and mRNA in kidney of diabetic rats elevated. In addition, the renal MMP-3 mRNA expression diminished in diabetic rats, while TIMP-1 and collagen Ⅲ mRNA increased. Conclusions In STZ-induced diabetic rats, the TGF-β1/Smad4 appears to play an important role in renal fibrosis of DN. The increased expression of TGF-β1 and Smad4 might result in the transcriptional regulation of downstream target genes of TGF-β1/Smad4 pathway, which contributes to the progression of renal fibrosis in diabetic rats.

Effects of interferon-alpha on expression of hepatic stellate cell and transforming growth factor-pi and a-smooth muscle actin in rats with hepatic fibrosis

AIM:To investigate the effect of interferon-a (IFN-α) on preventing or reversing hepatic fibrosis in rat experimental model induced by CCI4. METHODS: One hundred and ten Sprague-Dawley rats were divided into five groups: group A (normal controls, n = 18), group B (fibrotic model controls, n = 22), group C (IFN-α prevention, n = 22) initially treated with intramuscular injection of IFN-a in saline daily at the doses of 1× 105 U for 6 wk, group D (IFN-a treatment, n = 24) treated with intra-muscular injection of IFN-a in saline daily at the doses of 1×105 U for 6 wk after the first 6 wk, group E (0.9% sodium chloride treatment control, n = 24) treated with intra-muscular injection of 0.01 mL/kg daily for 6 wk after the first 6 wk. At the end of the experiment, all rats of each group were killed. Samples of the liver obtained by biopsy were subjected to histological, immunohistochemical and electron microscopic studies for the expressions of transforming growth factor-pi (TGF- μ41) and α-smooth muscle actin (α-SMA). RESULTS: The expressions of TGF-pl, the number of activated hepatic stellate cells and a-SMA in hepatic tissue of group C were significantly less than those of group B (P<0.01). The degree of fibrosis score in group B was also significantly less than that of group C under light microscope (P<0.01). CONCLUSION: IFN-a can inhibit the production of TGF-pl, decrease HSC activation and stimulate its apoptosis.

IMMUNORESPONSES OF HUMANIZED SCID MICE TO HUMAN LUNG CANCER CELLS

HuPBLSCID mice were used to explore how they would response to human tumor cells of 80llMLC.Living 80llMLC cells appeared to be fetal to the the mice due to the production of human TNF- The hupBL-SCID mice did not generate any noticeable amount of specific human immunoglobulin either by single immunization with living 801/MLC cells or by repeated immunization with irradiated 80llMLC cells. Our preliminary experiments with huPBL-SCID mice showed that such chimeras would be a very useful models for tumor immunological researches.

当代汉语区别词指称化、名词化的功用、趋势与动因——兼论现代汉语教学对新兴语言现象的吸收

文章认为,当代汉语区别词的指称化、名词化,其表达方式大多是用来回指与转指,表达需求重在对举与配合,表达效果主要是为了直接与明快。转化的性质与扩展趋势,大致涉及语用需要到功能定型、临时用法到词性转类、句子成分到句法成分。转化机制包括转喻与类推,转化动因是感染与和谐、追求简捷与求新的语用功效。当前现代汉语的教学必须重视科学性与时代性、实用性与可教性。

侗歌艺术传承场域的话语空间与信息域生成

从比较的角度,讨论源自于传统的侗歌艺术传承场域话语方式与后现代情境下信息意义拓展及转化之间的关联。分析认为,现代语境下,侗歌艺术传承场域要素构成及其活动空间、话语方式,借助源自于传统的基础性条件和内在性根源,完全有可能让审美主体感知意义世界和审美世界的方式(一种有别于日常生存又植根于日常生存的方式)得以不断生成日臻丰富、完善,且让审美主体的审美自觉性和审美创造力,在现实人化和审美化过程中,转化为后现代情境下渴望意义系统整合和信息域得以拓展的动因。

DNA methylation level of promoter region of activating transcription factor 5 in glioma

Transcription factors, which represent an important class of proteins that play key roles in controlling cellular proliferation and cell cycle modulation, are attractive targets for cancer therapy. Previous researches have shown that the expression level of activating transcription factor 5 （ATF5） was frequently increased in glioma and its acetylation level was related to glioma. The purposes of this study were to explore the methylation level of ATF5 in clinical glioma tissues and to explore the effect of ATF5 methylation on the expression of ATF5 in glioma. Methylation of the promoter region of ATF5 was assayed by bisulflte-specific polymerase chain reaction （PCR） sequencing analysis in 35 cases of glioma and 5 normal tissues. Quantitative real-time PCR （qRT-PCR） was also performed to detect ATF5 mRNA expression in 35 cases of glioma and 5 normal tissues. Clinical data were collected from the patients and analyzed. The percentages of methylation of the ATF5 gene in the promoter region in healthy control, patients with well-differentiated glioma, and those with poorly differentiated glioma were 87.78%, 73.89%, and 47.70%, respectively. Analysis of the methylation status of the promoter region of the ATF5 gene showed a gradually de- creased methylation level in poorly differentiated glioma, well-differentiated glioma, and normal tissues （P〈0.05）. There was also a significant difference between well-differentiated glioma and poorly differentiated glioma （P〈0.05）. ATF5 mRNA expression in glioma was significantly higher than that in the normal tissues （P〈0.05）. This study provides the first evidence that the methylation level of ATF5 decreased, and its mRNA expression was evidently up-regulated in glioma.

Emerging roles of non-coding RNAs in epigenetic regulation

Recent deep sequencing surveys of mammalian genomes have unexpectedly revealed pervasive and complex transcription and identified tens of thousands of RNA transcripts that do not code for proteins. These non-coding RNAs(nc RNAs) highlight the central role of RNA in gene regulation. nc RNAs are arbitrarily divided into two main groups: The first includes small RNAs, such as mi RNAs, pi RNAs, and endogenous si RNAs, that usually range from 20 to 30 nt, while the second group includes long non-coding RNAs(lnc RNAs), which are typically more than 200 nt in length. These nc RNAs were initially thought to merely regulate gene expression at the post-transcriptional level, but recent studies have indicated that nc RNAs, especially lnc RNAs, are extensively associated with diverse chromatin remodeling complexes and target them to specific genomic loci to alter DNA methylation or histone status. These findings suggest an emerging theme of nc RNAs in epigenetic regulation. In this review, we discuss the wide spectrum of nc RNAs in the regulation of DNA methylation and chromatin state, as well as the key questions that needs to be investigated and acknowledging the elegant design of these intriguing macromolecules.

Hydraulic pressure inducing renal tubular epithelial-myofibroblast transdifferentiation in vitro

Objective： The effects of hydraulic pressure on renal tubular epithelial-myofibroblast transdifferentiation （TEMT） were investigated. Methods： We applied hydraulic pressure （50 cmH2O） to normal rat kidney tubular epithelial cells （NRK52E） for different durations. Furthermore, different pressure magnitudes were applied to cells. The morphology, cytoskeleton, and expression ofmyofibroblastic marker protein and transforming growth factor-β1 （TGF-β1） of NRK52E cells were examined. Results Disorganized actin filaments and formation of curling clusters in actin were seen in the cytoplasm of pressurized cells. We verified that de novo expression α-smooth muscle actin induced by pressure, which indicated TEMT, was dependent on both the magnitude and duration of pressure. TGF-β1 expression was significantly upregulated under certain conditions, which implies that the induction of TEMT by hydraulic pressure is related with TGF-β1. Conclusion： We illustrate for the first time that hydraulic pressure can induce TEMT in a pressure magnitude- and duration-dependent manner, and that this TEMT is accompanied by TGF-β1 secretion.

Differential gene expression profile of Buyanghuanwu decoction in rats with ventricular remodeling post-myocardial infarction

OBJECTIVE: To investigate the effect of Buyanghuanwu decoction(BYHWD) on gene expression in ventricular remodeling post-myocardial infarction in rats.METHODS: Animal models of myocardial infarction were established by permanent ligation of the left anterior descending coronary artery. Echocardiography measurements were performed after the treatment of BYHWD(18 g·kg-1 collagen was observ·d-1) for 90 days.Myocardialed by mallory trichrome staining. Capillary density was quantified by using Factor rentially expⅧre immunohistochemical staining.Diffessed genes were explored by a short-read sequencing technology combined with a tag-based digital gene expression profiling(DGE)system. Real-time quantitative polymerase chain reaction detecting system(q PCR) was used to validate the sequencing results. After assembling the gene information from Sham, model and BYHWD groups, we constructed three DGE libraries based on each group. The sequencing of three libraries generated 66 000-73 000 unique tags, which were mapped to reference sequences for annotation of expressed genes.RESULTS: Among them, 511 and 352 differentially expressed genes were found in comparison with sham/model and model/BYHWD, respectively. Fifty-five genes exhibited reversed direction of gene expression differences between Sham/Model and Model/BYHWD groups. We found that transforming growth factor beta receptor-1, junctophilin-2,monocyte chemotactic protein 1, neuropeptide Y,arachidonate 5-Lipoxygenase, arachidonate 15-Lipoxygenase were significantly modulated, which suggested the involvement of these genes in BYHWD treatment.CONCLUSION: The DGE profiling data provide comprehensive gene expression information at the transcriptional level that could facilitate our understanding of the pharmacological mechanisms of BYHWD in ventricular remodeling post-myocardial infarction.