180 research outputs found

    Muscle Atrophy and Motor Neuron Degeneration in Human NEDL1 Transgenic Mice

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    Amyotrophic lateral sclerosis (ALS) is the most frequent adult-onset motor neuron disease. Approximately 20% cases of familial ALS show the mutation in the superoxide dismutase-1 (SOD1) gene. We previously demonstrated that homologue to E6AP carboxyl terminus- (HECT-) type ubiquitin protein E3 ligase (NEDL1) physically bind to mutated SOD1 protein but not wild-type SOD1 and promote the degradation of mutated SOD1 protein through ubiquitin-mediated proteasome pathway. To further understand the role of NEDL1 involved in the pathogenesis of familial ALS, we generated transgenic mice with human NEDL1 cDNA. The transgenic mice with human NEDL1 expression showed motor dysfunctions in rotarod, hanging wire, and footprint pattern examination. Histological studies indicated degeneration of neurons in the lumbar spinal cord and muscle atrophy. The number of activated microglia in the spinal cord of transgenic mice was significantly higher than that of wild-type mice, suggesting that inflammation might be observed in the spinal cord of transgenic mice. In conclusion, these findings suggest that the human NEDL1 transgenic mice might develop ALS-like symptoms, showing signs of motor abnormalities, accompanied with significant reduction in muscle strength

    Characteristics of leachate from selected MSW landfills and relationships with river water chemistry.

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    Leachate from three different landfills was characterized and its relationship with river water chemistry was evaluated to gain information for further improvement of current leachate management. The leachate from both active uncontrolled and closed controlled landfills was in methanogenic phase, while active controlled landfill was in acidic phase. There could be a relationship between leachate from uncontrolled landfill and river water chemistry, mainly as NH3-N, TOC and Fe. Whereas treatment of organic NH3-N and metals such as Fe, Mn, Cu, Cd and Cr was necessary as leachate in active controlled landfill high in organics, ammonia and pyrite oxidation was expected in the nearby stream. In addition denitrification of leachate might be required at closed controlled landfill. Management of landfill leachate is considered complicated and challenging due to the variation in its composition and the environmental problems associated with the pollutants produced. This variation is often attributed to the age of the landfill, amount and type of waste disposed, biological decomposition of waste, solubilization of soluble salts in waste, climate and moisture content in waste itself (Tchobanogolous et al., 1993). Moreover, leachate in Malaysia is highly heterogeneous due to the fact that wastes are not separated at source. Thus, leachate characteristics could be specific for each landfill and its information is very important in determining a suitable treatment method. Unfortunately, this basic information is still scarce in the country as monitoring of leachate characteristics are expensive and time-consuming

    Perfect kagome-lattice antiferromagnets with Jeff_{eff} = 1/2: The Co2+^{2+}-analogs of copper minerals volborthite and vesignieite

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    We report the synthesis, crystal structure, and magnetic properties of Co2+^{2+} kagome magnets Co3_3V2_2O7_7(OH)2_2\cdot2H2_2O and BaCo3_3(VO4_4)2_2(OH)2_2, which can be recognized as Co-analogues of the intensively researched quantum kagome magnet volborthite Cu3_3V2_2O7_7(OH)2_2\cdot2H2_2O and vesignieite BaCu3_3(VO4_4)2_2(OH)2_2. For each compound, the ground state is seemingly A-type antiferromagnetic order. At low temperatures, applying a magnetic field causes a metamagnetic-like transition described by the transition in which antiferromagnetically-aligned canted moments change to ferromagnetically-aligned ones. These ground and field-induced states include a canted ferromagnetic component perpendicular to the kagome planes favored by Dzyaloshinskii-Moriya interactions. These magnetic properties are well characterized by the Jeff_{eff} = 1/2 physics. Our findings will be the first step toward clarifying the Jeff_{eff} = 1/2 kagome physics, which has been little studied experimentally or theoretically.Comment: 9 pages, 7+1 figures, accepted for publication in Physical Review

    A Possible Scenario for Environmental Remediation in Coastal Waters by Use of Phytoplankton and Waste Materials

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    environmental remediationphytoplanktonseafood productionsewagesteelmaking sla

    Measuring organic carbon, nutrients and heavy metals in rivers receiving leachate from controlled and uncontrolled municipal solid waste landfills

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    Since landfilling is the common method of waste disposal in Malaysia, river water is greatly exposed to the risk of contamination from leachate unless proper leachate management is carried out. In this study, leachates from three different types of landfills, namely active uncontrolled, active controlled and closed controlled, were characterized, and their relationships with river water chemistry were examined monthly for a year. The influence of leachate on river water chemistry from each type of landfill depended on many factors, including the presence of a leachate control mechanism, leachate characteristics, precipitation, surface runoff and the applied treatment. The impact of leachate from an active uncontrolled landfill was the highest, as the organic content, NH(4)(+)-N, Cd and Mn levels appeared high in the river. At the same time, influences of leachate were also observed from both types of controlled landfills in the form of inorganic nitrogen (NH(4)(+)-N, NO(3)(-)-N and NO(2)(-)-N) and heavy metals (Fe, Cr, Ni and Mn). Improper treatment practice led to high levels of some contaminants in the stream near the closed controlled landfill. Meanwhile, the active controlled landfill, which was located near the coastline, was exposed to the risk of contamination resulting from the pyrite oxidation of the surrounding area

    Biologically driven DOC release from peatlands during recovery from acidification

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    Peatlands recovering from acidification release dissolved organic carbon (DOC), but no biological role has yet been identified in this process. Here, the authors show that pH increases enhance phenol oxidase activity, pore-water DOC concentrations and lead to greater abundances in Actinobacteria and fungi

    A Simple PCR Method for Rapid Genotype Analysis of the TH-MYCN Transgenic Mouse

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    BACKGROUND: The TH-MYCN transgenic mouse is the most widely used murine model of human neuroblastoma, in which a human MYCN oncogene is targeted to neuroectodermal cells of developing mice under the influence of the rat tyrosine hydroxylase promoter. So far, homozygous transgenic mice have been identified by either Southern blot or quantitative real-time PCR. PRINCIPAL FINDINGS: To establish a simple and reliable genotyping method by conventional PCR, we confirmed the integration of the transgene in the TH-MYCN transgenic mouse by Southern blot and inverse PCR analyses. Our results showed that either five or six copies were found to be inserted in a head-to-tail tandem configuration at a single locus. The MYCN transgene/host DNA junction was sequenced and the integration site was identified at chromosome 18qE4. Finally, we succeeded in designing rapid, simple and reliable genotyping method by common PCR using primers flanking the integrated TH-MYCN transgene. CONCLUSION: We established a simple and reliable genotyping PCR method for determining the integration site of the TH-MYCN transgene that enables all possible genotypes to be distinguished within several hours. TH-MYCN mice are excellent model for human neuroblastoma study, thus our results will largely be useful for facilitating the pace of neuroblastoma study, including in the study of the tumourigenic process, and in the development of therapies to treat patients suffering from neuroblastoma
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