2,632 research outputs found

    A fossil bolster plant from the King River, Tasmania

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    A macrofossil of the alpine bolster plant Donatia novae-zelandiae was found in the King River Valley, approximately 230 m above sea level in central western Tasmania. The fossil was in situ on a palaeosol that appears to have formed immediately prior to the late Last Glacial Maximum. An age of 21 180 + 370 years b.p. was established by radiocarbon dating. Pollen and present day distributional data suggest that the tree line was then at least 750 m lower than at present, implying a temperature depression of about 4.5 0 C. Scanning electron-micrographs and photomicrographs of the extant and fossil bolster species are presented

    A re-appraisal of the reliability of the 20 m multi-stage shuttle run test

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    This is the author's PDF version of an article published in European journal of applied physiology in 2007. The original publication is available at www.springerlink.co

    Life v2.0 - Quo vadis Homo sapiens?

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    The TgsGP gene is essential for resistance to human serum in Trypanosoma brucei gambiense

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    Trypanosoma brucei gambiense causes 97% of all cases of African sleeping sickness, a fatal disease of sub-Saharan Africa. Most species of trypanosome, such as T. b. brucei, are unable to infect humans due to the trypanolytic serum protein apolipoprotein-L1 (APOL1) delivered via two trypanosome lytic factors (TLF-1 and TLF-2). Understanding how T. b. gambiense overcomes these factors and infects humans is of major importance in the fight against this disease. Previous work indicated that a failure to take up TLF-1 in T. b. gambiense contributes to resistance to TLF-1, although another mechanism is required to overcome TLF-2. Here, we have examined a T. b. gambiense specific gene, TgsGP, which had previously been suggested, but not shown, to be involved in serum resistance. We show that TgsGP is essential for resistance to lysis as deletion of TgsGP in T. b. gambiense renders the parasites sensitive to human serum and recombinant APOL1. Deletion of TgsGP in T. b. gambiense modified to uptake TLF-1 showed sensitivity to TLF-1, APOL1 and human serum. Reintroducing TgsGP into knockout parasite lines restored resistance. We conclude that TgsGP is essential for human serum resistance in T. b. gambiense

    Commensal bacteria augment Staphylococcus aureus infection by inactivation of phagocyte-derived reactive oxygen species

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    Staphylococcus aureus is a human commensal organism and opportunist pathogen, causing potentially fatal disease. The presence of non-pathogenic microflora or their components, at the point of infection, dramatically increases S. aureus pathogenicity, a process termed augmentation. Augmentation is associated with macrophage interaction but by a hitherto unknown mechanism. Here, we demonstrate a breadth of cross-kingdom microorganisms can augment S. aureus disease and that pathogenesis of Enterococcus faecalis can also be augmented. Co-administration of augmenting material also forms an efficacious vaccine model for S. aureus. In vitro, augmenting material protects S. aureus directly from reactive oxygen species (ROS), which correlates with in vivo studies where augmentation restores full virulence to the ROS-susceptible, attenuated mutant katA ahpC. At the cellular level, augmentation increases bacterial survival within macrophages via amelioration of ROS, leading to proliferation and escape. We have defined the molecular basis for augmentation that represents an important aspect of the initiation of infection

    Evolutionary diversification of the trypanosome haptoglobin-haemoglobin receptor from an ancestral haemoglobin receptor.

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    The haptoglobin-haemoglobin receptor of the African trypanosome species, Trypanosoma brucei, is expressed when the parasite is in the bloodstream of the mammalian host, allowing it to acquire haem through the uptake of haptoglobin-haemoglobin complexes. Here we show that in Trypanosoma congolense this receptor is instead expressed in the epimastigote developmental stage that occurs in the tsetse fly, where it acts as a haemoglobin receptor. We also present the structure of the T. congolense receptor in complex with haemoglobin. This allows us to propose an evolutionary history for this receptor, charting the structural and cellular changes that took place as it adapted from a role in the insect to a new role in the mammalian host.Medical Research Counci

    Successful treatment of recurrent small bowel adenocarcinoma by cytoreductive surgery and chemotherapy: a case report and review of the literature

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    <p>Abstract</p> <p>Introduction</p> <p>Small bowel adenocarcinoma is a rare malignancy associated with a poor prognosis and there is little evidence of effective treatment. Recurrent small bowel adenocarcinoma is an intractable disease for which there is little information available regarding its treatment by palliative therapy. We present a case of recurrent small bowel adenocarcinoma successfully treated by cytoreductive surgery and palliative chemotherapy.</p> <p>Case presentation</p> <p>We report the case of a 72-year-old Japanese female who developed a peritoneal metastasis from recurrent small bowel adenocarcinoma after curative resection and adjuvant chemotherapy with S-1 and polysaccharide K. She underwent cytoreductive surgery followed by chemotherapy with folinic acid/fluorouracil/oxaliplatin and folinic acid/fluorouracil/irinotecan with polysaccharide K. Subsequently, no sign of a recurrence was observed 42 months after the second operation.</p> <p>Conclusion</p> <p>To the best of our knowledge, this is the first case report of the successful treatment of peritoneal metastasis from small bowel adenocarcinoma by cytoreductive surgery and combination chemotherapy (folinic acid/fluorouracil/oxaliplatin and folinic acid/fluorouracil/irinotecan with polysaccharide K).</p
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