70 research outputs found

    Mastication in the tuatara, Sphenodon punctatus (reptilia: Rhynchocephalia): Structure and activity of the motor system

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    The masticatory pattern of Sphenodon punctatus , the sole remaining rhynchocephalian, now restricted to islands off the coast of New Zealand, has been analyzed by detailed anatomy, cinematography, cinefluoroscopy, and electromyography. Food reduction consists of a closing, crushing bite followed by a propalineal sliding of the dentary row between the maxillary and palatine ones. The large, fleshy tongue can be protruded to pick up small prey, and also plays a major role in prey manipulation. The rotational closing movement of the jaw, supporting the basic crushing movement, is induced by the main adductor musculature. It is followed by a propalineal anterior displacement relying heavily on the action of the M. pterygoideus. The fiber lengths of the several muscles reflect the extent of shortening. The most obvious modification appears in the M. pterygoideus, which contains a central slip of pinnately arranged short fibers that act a period different from that of the rest of the muscle; their action increases the power during the terminal portion of the propalineal phase. This also allows the animal to use its short teeth in an effective shearing bite that cuts fragments off large prey. The action of single cusped dentary teeth acting between the maxillary and palatine tooth rows provides a translational crushing-cutting action that may be an analog of the mammalian molar pattern. However, this strictly fore-aft slide does not incorporate capacity for later development of lateral movement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50277/1/1051710307_ftp.pd

    The genome of the emerging barley pathogen Ramularia collo-cygni

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    Background Ramularia collo-cygni is a newly important, foliar fungal pathogen of barley that causes the disease Ramularia leaf spot. The fungus exhibits a prolonged endophytic growth stage before switching life habit to become an aggressive, necrotrophic pathogen that causes significant losses to green leaf area and hence grain yield and quality. Results The R. collo-cygni genome was sequenced using a combination of Illumina and Roche 454 technologies. The draft assembly of 30.3 Mb contained 11,617 predicted gene models. Our phylogenomic analysis confirmed the classification of this ascomycete fungus within the family Mycosphaerellaceae, order Capnodiales of the class Dothideomycetes. A predicted secretome comprising 1053 proteins included redox-related enzymes and carbohydrate-modifying enzymes and proteases. The relative paucity of plant cell wall degrading enzyme genes may be associated with the stealth pathogenesis characteristic of plant pathogens from the Mycosphaerellaceae. A large number of genes associated with secondary metabolite production, including homologs of toxin biosynthesis genes found in other Dothideomycete plant pathogens, were identified. Conclusions The genome sequence of R. collo-cygni provides a framework for understanding the genetic basis of pathogenesis in this important emerging pathogen. The reduced complement of carbohydrate-degrading enzyme genes is likely to reflect a strategy to avoid detection by host defences during its prolonged asymptomatic growth. Of particular interest will be the analysis of R. collo-cygni gene expression during interactions with the host barley, to understand what triggers this fungus to switch from being a benign endophyte to an aggressive necrotroph

    Coordinating with the Future: The Anticipatory Nature of Representation

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    Allergen-stimulated expression of interleukin (IL)-17 isoforms in mice

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    Univ São Paulo, Res Ctr Vet Toxicol CEPTOX, BR-05508 São Paulo, BrazilUniversidade Federal de São Paulo, Sch Pharm & Biochestry, São Paulo, BrazilUniversidade Federal de São Paulo, Sch Pharm & Biochestry, São Paulo, BrazilWeb of Scienc

    Splenectomy Associated Changes in IgM Memory B Cells in an Adult Spleen Registry Cohort

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    Asplenic patients have a lifelong risk of overwhelming post-splenectomy infection and have been reported to have low numbers of peripheral blood IgM memory B cells. The clinical value of quantitation of memory B cells as an indicator of splenic abnormality or risk of infection has been unclear. To assess changes in B cell sub-populations after splenectomy we studied patients recruited to a spleen registry (n = 591). A subset of 209 adult asplenic or hyposplenic subjects, and normal controls (n = 140) were tested for IgM memory B cells. We also determined a) changes in IgM memory B cells with time after splenectomy using the cross-sectional data from patients on the registry and b) the kinetics of changes in haematological markers associated with splenectomy(n = 45). Total B cells in splenectomy patients did not differ from controls, but memory B cells, IgM memory B cells and switched B cells were significantly (p<0.001) reduced. The reduction was similar for different indications for splenectomy. Changes of asplenia in routine blood films including presence of Howell-Jolly bodies (HJB), occurred early (median 25 days) and splenectomy associated thrombocytosis and lymphocytosis peaked by 50 days. There was a more gradual decrease in IgM memory B cells reaching a stable level within 6 months after splenectomy. IgM memory B cells as proportion of B cells was the best discriminator between splenectomized patients and normal controls and at the optimal cut-off of 4.53, showed a true positive rate of 95% and false positive rate of 20%. In a survey of 152 registry patients stratified by IgM memory B cells around this cut-off there was no association with minor infections and no registry patients experienced OPSI during the study. Despite significant changes after splenectomy, conventional measures of IgM memory cells have limited clinical utility in this population

    Does zearalenone, an estrogenic mycotoxin, have immunotoxic effects?

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    Universidade Federal de São Paulo, Sch Pharm & Biochem, São Paulo, BrazilUniv São Paulo, Sch Vet Med & Anim Sci, BR-05508 São Paulo, BrazilUniversidade Federal de São Paulo, Sch Pharm & Biochem, São Paulo, BrazilWeb of Scienc
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