1,955 research outputs found

    Myelin basic protein peptide 45–89 induces the release of nitric oxide from microglial cells.

    No full text
    Continuous (24 h) exposure of mixed oligodendrocyte/microglial cells to peptides 45–89 derived from citrullinated C8 isoforms of myelin basic protein (MBP) induces cell death. In contrast, MBP-C8 at the same molecular concentration is not toxic to oligodendrocyte/microglial cells as detected by the MTT test and trypan blue exclusion method. The loss of oligodendrocyte/microglial cells resulted in the release of cytochrome c from mitochondria, suggesting MBP 45–89-induced apoptosis. On the other hand, peptides 45–89 stimulated the secretion of nitric oxide from microglial cells only via induction of iNOS. The addition of peptide 45–89 to the microglial cells led to a decrease of the level of the inhibitory protein IkB, indicating that activation of the transcription factor NF-kB is involved in these processes. We propose that the immunodominant peptide 45–89 induces damage of oligodendrocytes by activation of microglial cells and subsequent generation of nitric oxide, and that this may be the first step in the initiation of autoimmunity

    A study of load support and other criteria appropriate to the selection of industrial conveyor belts

    Get PDF
    A study of conveying practice demonstrates that belt conveyors provide a versatile and. much-used method of transporting bulk materials, but a review of belting manufacturers' design procedures shows that belt design and selection rules are often based on experience with all-cotton belts no longer in common use, and are net completely relevant to modern synthetic constructions. In particular, provision of the property "load support", which was not critical with cotton belts, is shown to determine the outcome of most belt selection exercises and lead to gross over specification of other design properties in many cases. The results of an original experimental investigation into this property, carried out to determine the belt and conveyor parameters that affect it, how the major role that belt stiffness plays in its provision; the basis for a belt stiffness test relevant to service conditions is given. A proposal for a more rational method of specifying load support data results from the work, but correlation of the test results with service performance is necessary before the absolute toad support capability required from a belt for given working conditions can be quantified. A study to attain this correlation is the major proposal for future work resulting from the present investigation, but a full review of the literature on conveyor design and a study of present practice within the belting industry demonstrate other, less critical, factors that could profitably be investigated. It is suggested that the most suitable method of studying these would be a rational data collection system to provide information on various facets of belt service behaviour; a basis for such a system is proposed. In addition to the work above, proposals for simplifying the present belt selection methods are made and a strain transducer suitable for use in future experimental investigations is developed

    Self-esteem, shyness, and sociability in adolescents with specific language impairment (SLI)

    Get PDF
    Purpose: To determine if lower global self-esteem, shyness, and low sociability are outcomes associated with SLI in adolescence. Possible concurrent predictive relationships and gender differences were also examined. Method: Fifty-four adolescents with SLI, aged between 16 and 17 years, were compared with a group of 54 adolescents with typical language abilities on the Rosenberg Self-Esteem scale (Rosenberg, 1965) and the Cheek and Buss Shyness and Sociability scales (Cheek & Buss, 1981). Results: The SLI group had significantly lower global self-esteem scores than the group with typical language abilities. The adolescents with SLI were more shy than their peers, but the groups did not differ in their sociability ratings. Regression analysis found that language ability was not concurrently predictive of self-esteem but shyness was. Mediation analysis suggested that shyness could be a partial but significant mediator in the relationship between language ability and global self-esteem. Conclusions: Older adolescents with SLI are at risk of lower global self-esteem and experience shyness, although they want to interact socially. The relationship between language ability and self-esteem at this point in adolescence is complex, with shyness potentially playing an important mediating role
    • 

    corecore