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Wei Deng

Publications and source records attributed to Wei Deng.

At least 37 records · Page 2Linked to original sources
PubMed2005

Somatic mosaicism in neuronal precursor cells mediated by L1 retrotransposition.

Revealing the mechanisms for neuronal somatic diversification remains a central challenge for understanding individual differences in brain organization and function. Here we show that an engineered human LINE-1 (for long interspersed nuclear element-1; also known as L1) element can retrotranspose in neuronal precursors derived from rat hippocampus neural stem cells. The resulting retrotransposition events can alter the expression of neuronal genes, which, in turn, can influence neuronal cell fate in vitro. We further show that retrotransposition of a human L1 in transgenic mice results in neuronal somatic mosaicism. The molecular mechanism of action is probably mediated through Sox2, because a decrease in Sox2 expression during the early stages of neuronal differentiation is correlated with increases in both L1 transcription and retrotransposition. Our data therefore indicate that neuronal genomes might not be static, but some might be mosaic because of de novo L1 retrotransposition events.

Animals↗
PubMed2005

NONCODE: an integrated knowledge database of non-coding RNAs.

NONCODE is an integrated knowledge database dedicated to non-coding RNAs (ncRNAs), that is to say, RNAs that function without being translated into proteins. All ncRNAs in NONCODE were filtered automatically from literature and GenBank, and were later manually curated. The distinctive features of NONCODE are as follows: (i) the ncRNAs in NONCODE include almost all the types of ncRNAs, except transfer RNAs and ribosomal RNAs. (ii) All ncRNA sequences and their related information (e.g. function, cellular role, cellular location, chromosomal information, etc.) in NONCODE have been confirmed manually by consulting relevant literature: more than 80% of the entries are based on experimental data. (iii) Based on the cellular process and function, which a given ncRNA is involved in, we introduced a novel classification system, labeled process function class, to integrate existing classification systems. (iv) In addition, some 1100 ncRNAs have been grouped into nine other classes according to whether they are specific to gender or tissue or associated with tumors and diseases, etc. (v) NONCODE provides a user-friendly interface, a visualization platform and a convenient search option, allowing efficient recovery of sequence, regulatory elements in the flanking sequences, secondary structure, related publications and other information. The first release of NONCODE (v1.0) contains 5339 non-redundant sequences from 861 organisms, including eukaryotes, eubacteria, archaebacteria, virus and viroids. Access is free for all users through a web interface at http://noncode.bioinfo.org.cn.

Base Sequence↗
PubMed2005

Land use/cover changes, the environment and water resources in northeast China.

Land use/cover in Northeast China went through extensive changes during the 1990s. This report explores the interaction between these changes and the environment, and the implication of these changes for rational allocation of water resources. Two maps of land use/cover produced from 1990 and 2000 Landsat TM satellite images were overlaid in Arc Info to reveal changes in land cover. Results indicate that farmland and grassland decreased by 386,195 and 140,075 ha, respectively, while water, built-up areas, and woodland increased by 238,596, 194,231, and 192,682 ha, respectively. These changes bore a mutual relationship with the environmental change. On the one hand, climate warming made some of these changes (e.g., conversion of woodland and grassland to farmland) possible. On the other hand, the changed surface cover modified the local climate. These changes, in turn, caused severe environmental degradation and increased flooding. The change between dry field and rice paddy, in particular, raised severe implications for the proper allocation of limited water resources in the Northeast. Efforts are needed to coordinate their rational allocation to reap maximum and sustainable return over the entire area, not just in some localities. Results obtained in this study should be of interest to the international audience of Environmental Management in that they highlight the interactive nature of human activities and the environment and the off-site impact of these activities on the environment.

Agriculture↗
PubMed2005

Variation of xylanosomal subunit composition of Streptomyces olivaceoviridis by nitrogen sources.

Besides affecting the xylanases production, different nitrogen sources present in the media also caused changes in the xylanosomal subunit composition of Streptomyces olivaceoviridis E-86. Four xylanosome fractions, purified from the culture supernatant of S. olivaceoviridis E-86 grown on different nitrogen sources, exhibited high specificity towards different xylans and were composed of different subunits. Thus, S. olivaceoviridis E-86 regulates the expression of xylanase activity and varies the xylanosome composition according to the nitrogen sources possibly through the action of the secreted proteases.

Culture Media↗
PubMed2005

[Purification of surface water nitrogen and phosphorus pollutants by Zhalong Riparian Wetland].

The laws of purification of stream nitrogen and phosphorus by riparian wetland was studied by sampling in Long'an Bridge and Shuiku Bridge reaches in Zhalong Wetland. Results from the spatial purifying equations show that two reaches exhibited persistent capability of purification of TP and PO4(3-) through out the seasons of spring, summer and fall, and the purifying coefficient of TP fluctuates from 0.00186 to 0.01175 mg x (L x km)(-1) while the PO4(3-)'s was from 2.5E-4 to 0.00704 mg x (L x km)(-1). As to TN, the purification occured only in the seasons of spring and summer while in fall it experienced accumulation downwards along the streamflow, and the output capability was up to 0.48175 mg x (L x km)(-1). Analysis of effect factors show runoff and input concentration have a certain influence on the purification capability.

Bacteria↗
PubMed2005

[Preventive and therapeutic effects of recombinant IFN-alpha2b nasal spray on SARS-CoV infection in Macaca mulata].

OBJECTIVE: To study the preventive and therapeutic effects of recombinant IFN-alpha2b for nasal spray on SARS-CoV infection in Macaca mulata (rhesus monkey). METHODS: Ten rhesus monkeys were divided into two groups, 5 in interferon group, and 5 in control group. Before and after SARS-CoV attack, the virus was detected in samples such as pharyngeal swab in all the two groups by Real-time PCR (RT-PCR) and virus isolation was performed. RESULTS: After virus attack, the level of SARS-CoV-specific IgG and neutralizing antibody were induced by SARS-CoV in the interferon group was weaker than in control group. Hematology items showed no apparent changes after virus attack in treated group. Through pathological examination, the morphology of the lung tissues of two Macaques in the treated group was normal, while the other three displayed the interstitial pneumonia with the thickened septum and infiltration with mononuclear cells. Among which, one monkey showed part of thickened septum fused with each other. These lesions in the interferon treated animals were similar to those seen in the animals in control group, but with smaller scope of pathological changes. No significant abnormity was detected in other organs. CONCLUSION: Recombinant IFN-alpha2b could effectively interdict or weaken SARS-CoV injury in monkeys.

Animals↗
PubMed2004

Reversibly switchable DNA nanocompartment on surfaces.

Biological macromolecules have been used to fabricate many nanostructures, biodevices and biomimetics because of their physical and chemical properties. But dynamic nanostructure and biomachinery that depend on collective behavior of biomolecules have not been demonstrated. Here, we report the design of DNA nanocompartments on surfaces that exhibit reversible changes in molecular mechanical properties. Such molecular nanocompartments are used to encage molecules, switched by the collective effect of Watson-Crick base-pairing interactions. This effect is used to perform molecular recognition. Furthermore, we found that 'fuel' strands with single-base variation cannot afford an efficient closing of nanocompartments, which allows highly sensitive label-free DNA array detection. Our results suggest that DNA nanocompartments can be used as building blocks for complex biomaterials because its core functions are independent of substrates and mediators.

Base Pair Mismatch↗
PubMed2004

Evidence for association between novel polymorphisms in the PRODH gene and schizophrenia in a Chinese population.

Haploinsufficiency for or mutation in at least one gene from the velocardiofacial syndrome (VCFS) region at chromosome 22q11 is implicated in psychosis. Linkage disequilibrium mapping of the region in patients identified a segment containing two genes, proline dehydrogenase (PRODH) and DGCR6, as candidates [Liu et al., 2002a] and by analysis of additional polymorphisms the PRODH gene was associated with schizophrenia in adult and early onset patients. In the present study we provide additional evidence in support of genetic association between PRODH and schizophrenia in a Chinese population. We analyzed the PRODH gene in a samples of schizophrenic patients and their families from Sichuan, SW China consisting of 528 family trios and sibling pairs. We genotyped six SNPs, PRODH*1195C-->T, PRODH*1482C-->T, PRODH*1483A-->G, PRODH*1766A-->G, PRODH*1852G-->A PRODH*1945T-->C, two of which (PRODH*1483A-->G and PRODH*1852G-->A) have not been previously reported. We found association with schizophrenia for two haplotypes consisting of PRODH*1945T-->C and PRODH*1852G-->A (Global P = 0.006), and PRODH*1852G-->A and PRODH*1766A-->G (Global P = 0.01) which include one of the newly identified markers. After six-fold Bonferroni correction for multiple testing the PRODH*1945T-C/PRODH*1852G-A haplotypes remained significant. This is a sub-haplotype of the PRODH haplotype previously associated with schizophrenia and it also maps to the 3' region of the gene, indicating that this is the region most likely to contain the underlying risk alleles. Overall this finding supports a role for the PRODH locus in schizophrenia.

Alleles↗
PubMed2004

Angiogenesis in rabbit hepatic tumor after transcatheter arterial embolization.

AIM: To investigate the effect of transcatheter arterial embolization (TAE) on angiogenesis of hepatic tumor. METHODS: Twenty New Zealand White rabbits were randomly divided into two groups of 10 each and VX2 carcinoma was implanted in the left medial lobes of the livers. Fourteen days later, a silicon catheter was inserted into the left hepatic artery of rabbit with VX2 hepatic tumor and infusion was performed via the hepatic artery using Lipiodol (the TAE group) or saline (the control group). Rabbits were sacrificed 7 d after treatment and tumor tissues were excised. Expression of vascular endothelial growth factor (VEGF) protein and microvessel density (MVD) of tumors were examined using immunohistochemistry. The staining intensity of VEGF was evaluated with a computer-assisted image-analyzer. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the VEGF mRNA expression of tumors. RESULTS: MVD was higher in the TAE group compared with the control group (28.6+/-10.6 vs 16.3+/-6.9, P<0.01). Expression of VEGF protein was enhanced after TAE. The staining intensity of VEGF in the TAE group was 0.162+/-0.018, significantly higher than in the control group (0.142+/-0.01, P<0.01). At mRNA level, VEGF165 mRNA was significantly higher in the TAE group compared with the control group (2.58+/-0.42 vs 1.99+/-0.21, P<0.001). MVD was well correlated to VEGF expression in both the TAE group (r=0.69, P<0.05) and the control group (r=0.72, P<0.05). CONCLUSION: TAE promotes the development of neovascularization of residual tumors through up-regulation of VEGF expression, possibly due to hypoxic insult.

Animals↗
PubMed2004

Evolution and migration history of the Chinese population inferred from Chinese Y-chromosome evidence.

Y-chromosomes from 76 Chinese men covering 33 ethnic minorities throughout China as well as the Han majority were collected as genetic material for the study of Chinese nonrecombinant Y-chromosome (NRY) phylogeny. Of the accepted worldwide NRY haplogroups, three (haplogroups D, C, O) were significant in this sample, extending previous assessments of Chinese genetic diversity. Based on geographic, linguistic, and ethnohistorical information, the 33 Chinese ethnic minorities in our survey were divided into the following four subgroups: North, Tibet, West, and South. Inferred from the distribution of the newly found immediate ancestor lineage haplogroup O*, which has M214 but not M175, we argue that the southern origin scenario of this most common Chinese Y haplogroup is not very likely. We tentatively propose a West/North-origin hypothesis, suggesting that haplogroup O originated in West/North China and mainly evolved in China and thence spread further throughout eastern Eurasia. The nested cladistic analysis revealed in detail a multilayered, multidirectional, and continuous history of ethnic admixture that has shaped the contemporary Chinese population. Our results give some new clues to the evolution and migration of the Chinese population and its subsequence moving about in this land, which are in accordance with the historical records.

Biological Evolution↗
PubMed2004

Mili, a mammalian member of piwi family gene, is essential for spermatogenesis.

The piwi family genes, which are defined by conserved PAZ and Piwi domains, play important roles in stem cell self-renewal, RNA silencing, and translational regulation in various organisms. To reveal the function of the mammalian homolog of piwi, we produced and analyzed mice with targeted mutations in the Mili gene, which is one of three mouse homologs of piwi. Spermatogenesis in the MILI-null mice was blocked completely at the early prophase of the first meiosis, from the zygotene to early pachytene, and the mice were sterile. However, primordial germ cell development and female germ cell production were not disturbed. Furthermore, MILI bound to MVH, which is an essential factor during the early spermatocyte stage. The similarities in the phenotypes of the MILI- and MVH-deficient mice and in the physical binding properties of MILI and MVH indicate a functional association of these proteins in post-transcriptional regulation. These data indicate that MILI is essential for the differentiation of spermatocytes.

Animals↗
PubMed2004

High dispersion and electrocatalytic properties of platinum nanoparticles on graphitic carbon nanofibers (GCNFs).

Highly dispersed platinum nanoparticles were electrodeposited on graphitic carbon nanofibers (GCNFs) by cyclic voltammetry (CV) in 7.7 mM H2PtCl6+0.5 M HCl aqueous solutions. The graphitic carbon nanofibers (GCNFs) used in this paper were grown directly on a graphite disk by chemical vapor deposition (CVD). The micrographs and element composition of Pt/GCNFs/graphite electrode were characterized by scanning electron microscopy (SEM) and electron diffraction spectroscopy (EDS). The electrocatalytic properties of Pt/GCNFs/graphite electrode for methanol oxidation have been investigated by CV and excellent electrocatalytic activity can be observed even at very low platinum loading (md=8.79 microg cm(-2)). The highest mass activity (MA) for methanol oxidation reaches 323 Ag(-1) when Pt/GCNFs/graphite electrode was cycled at a sweep rate of 50 mVs(-1) by CV in 2 M CH3OH+1 M H2SO4 aqueous solutions. This may be attributed to the small particle size and high dispersion of platinum particles coated on GCNFs and shows good potential application in direct methanol fuel cell (DMFC). Additionally, the long-term cycling stability of platinum catalysts was also investigated.

Journal Article↗
PubMed2004

A novel, ultra-large xylanolytic complex (xylanosome) secreted by Streptomyces olivaceoviridis.

The production of a novel, very large xylanolytic complex (xylanosome) by Streptomyces olivaceoviridis E-86 is reported. The molecular weight was approx. 1200 kDa as determined by native gradient gel electrophoresis. Corncob xylan was the best inducer of xylanosome formation. The xylanosome was produced when the organism was grown for 5 d between pH 4.5-6 and at 27.5 to 35 degrees C.

Cell Culture Techniques↗
PubMed2003

Speciation of chromium by in-capillary reaction and capillary electrophoresis with chemiluminescence detection.

A sensitive method for the simultaneous determination of chromium(III) (Cr3+) and chromium(VI) (CrO4(2-)) using in-capillary reaction, capillary electrophoresis (CE) separation and chemiluminescence (CL) detection was developed. The chemiluminescence reaction was based on luminol oxidation by hydrogen peroxide in basic aqueous solution catalyzed by Cr3+ ion followed by capillary electrophoresis separation. Based on in-capillary reduction, chromium(VI) can be reduced by acidic sodium hydrogensulfite to form chromium(III) while the sample is running through the capillary. Before the electrophoresis procedure, the sample (Cr3+ and CrO4(2-)), buffer and acidic sodium hydrogensulfite solution segments were injected in that order into the capillary, followed by application of an appropriate running voltage between both ends. As both chromium species have opposite charges, Cr3+ ions migrate to the cathode, while CrO4(2-) ions, moving in the opposite direction toward the anode, react with acidic sodium hydrogensulfite which results in the formation of Cr3+ ions. Because of the migration time difference of both Cr3+ ions, Cr(III) and Cr(VI) could be separated. The running buffer was composed of 0.02 mol l(-1) acetate buffer (pH 4.7) with 1 x 10(-3) mol l(-1) EDTA. Parameters affecting CE-CL separation and detection, such as reductant (sodium hydrogensulfite) concentration, mixing mode of the analytes with CL reagent, CL reaction reagent pH and concentration, were optimized. The limits of detection (LODs) of Cr(III) and Cr(VI) were 6 x 10(-13) and 8 x 10(-12) mol l(-1) (S/N=3), respectively. The mass LODs for Cr(III) and Cr(VI) were 1.2 x 10(-20) mol (12 zmol) and 3.8 x 10(-19) mol (380 zmol), respectively.

Buffers↗