1000 resultados para Axenhausen, Kay W


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The role of natural killer (NK) T cells in the development of lupus-like disease in mice is still controversial. We treated NZB/W mice with anti-NK1.1 monoclonal antibodies (mAbs) and our results revealed that administration of either an irrelevant immunoglobulin G2a (IgG2a) mAb or an IgG2a anti-NK1.1 mAb increased the production of anti-dsDNA antibodies in young NZB/W mice. However, the continuous administration of an anti-NK1.1 mAb protected aged NZB/W mice from glomerular injury, leading to prolonged survival and stabilization of the proteinuria. Conversely, the administration of the control IgG2a mAb led to an aggravation of the lupus-like disease. Augmented titres of anti-dsDNA in NZB/W mice, upon IgG2a administration, correlated with the production of BAFF/BLyS by dendritic, B and T cells. Treatment with an anti-NK1.1 mAb reduced the levels of interleukin-16, produced by T cells, in spleen cell culture supernatants from aged NZB/W. Adoptive transfer of NK T cells from aged to young NZB/W accelerated the production of anti-dsDNA in recipient NZB/W mice, suggesting that NK T cells from aged NZB/W are endowed with a B-cell helper activity. In vitro studies, using purified NK T cells from aged NZB/W, showed that these cells provided helper B-cell activity for the production of anti-dsDNA. We concluded that NK T cells are involved in the progression of lupus-like disease in mature NZB/W mice and that immunoglobulin of the IgG2a isotype has an enhancing effect on antibody synthesis due to the induction of BAFF/BLyS, and therefore have a deleterious effect in the NZB/W mouse physiology.

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The Australian Alfred Walter Campbell (1868-1937) is remembered as one of the two chief pioneers of the study of the cytoarchitectonics of the primate cerebral cortex. He had worked in Britain carrying out neuroanatomical and neuropathological research for almost two decades before his famous monograph on Histological Studies on the Localisation of Cerebral Function appeared in 1905. In that year he returned to his native Australia and practiced for over 30 years in Sydney as a neurologist rather than a neuropathologist, publishing mainly clinical material though he was involved in the investigation of the epidemic of Australian X disease, a viral encephalitis. His abrupt change in both the nature and the location of his career at a time when he was well established in Britain appears to have been a consequence of his marriage and the need to provide for a family. His simultaneous apparent abandonment of research seems not to have really been the case. As judged from the contents of a paper presented to a local medical congress in Sydney in 1911, it appears that, in Australia, Campbell did carry out a major comparative anatomical and histological investigation of the possibility of localization of function in the cerebellar cortex. He never published this work in detail. His investigation let him to conclude that no such localization of function existed, a view contrary to the then topical interpretation of Bolk (1906), but one in accordance with Gordon Holmes' views a decade later. Campbell's circumstances in Sydney, his extremely reticent nature and the essentially negative outcome of his investigation probably explain his failure to make his study more widely known.

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Active surveillance for dengue (DEN) virus infected mosquitoes can be an effective way to predict the risk of dengue infection in a given area. However, doing so may pose logistical problems if mosquitoes must be kept alive or frozen fresh to detect DEN virus. In an attempt to simplify mosquito processing, we evaluated the usefulness of a sticky lure and a seminested reverse-transcriptase polymerase chain reaction assay (RT-PCR) for detecting DEN virus RNA under laboratory conditions using experimentally infected Aedes aegypti (L.) mosquitoes. In the first experiment, 40 male mosquitoes were inoculated with 0.13 mul of a 10(4) pfu/ml DEN-2 stock solution. After a 7-d incubation period, the mosquitoes were applied to the sticky lure and kept at room temperatures of 23-30 degreesC. Following 7,10,14, and 28 d application, 10 mosquitoes each were removed from the lure pooled and assayed for virus. DEN virus nucleic acid was clearly detectable in all pools up to 28 d after death. A second study evaluated sensitivity and specificity using one, two, and five DEN-infected mosquitoes removed after 7, 10, 14, 21 and 30 d application and tested by RT-PCR. All four DEN serotypes were individually inoculated in mosquitoes and evaluated using the same procedures as experiment 1. The four serotypes were detectable in as few as one mosquito 30 d after application to the lure with no evidence of cross-reactivity. The combination of sticky lures and RT-PCR show promise for mosquito and dengue virus surveillance and warrant further evaluation.

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Brushtail possums, Trichosurus vulpecula Kerr, were experimentally infected with Ross River (RR) or Barmah Forest (BF) virus by Aedes vigilax (Skuse) mosquitoes. Eight of 10 animals exposed to RR virus developed neutralizing antibody, and 3 possums developed high viremia for < 48 hr after infection, sufficient to infect recipient mosquitoes. Two of 10 animals exposed to BF virus developed neutralizing antibody. Both infected possums maintained detectable neutralizing antibody to BF for at least 45 days after infection (log neutralization index > 2.0 at 45 days). Eight possums did not develop neutralizing antibody to BF despite exposure to infected mosquitoes. These results suggest that T. vulpecula may potentially act as a reservoir species for RR in urban areas. However, T. vulpecula infected with BF do not develop viremia sufficient to infect mosquitoes and are unlikely to be important hosts for BF.

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Aim: The pseudo-Pelger-Huet (PH) anomaly has been associated with a variety of primary haematological disorders, infections and drugs. Recently, the development of dysgranulopoiesis characterised by a pseudo-PH anomaly has been reported in two patients with the use of mycophenolate mofetil (MMF) in the setting of heart and/or lung transplantation. We present a further five cases of MMF-related dysgranulopoiesis characterised by a pseudo-PH anomaly occurring after renal transplantation. Methods: All patients were receiving standard immunosuppression protocols for renal transplantation, including a combination of MMF, steroids and either cyclosporin or tacrolimus. Oral ganciclovir was also used for cytomegalovirus prophylaxis in each case. Results: Development of dysplastic granulopoiesis occurred a median of 96 days (range 66-196 days) after transplantation. Moderate or severe neutropaenia (

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The short-lived Hf-182-W-182-isotope system is an ideal clock to trace core formation and accretion processes of planets. Planetary accretion and metal/silicate fractionation chronologies are calculated relative to the chondritic Hf-182-W-182-isotope evolution. Here, we report new high-precision W-isotope data for the carbonaceous chondrite Allende that are much less radiogenic than previously reported and are in good agreement with published internal Hf-W chronometry of enstatite chondrites. If the W-isotope composition of terrestrial rocks, representing the bulk silicate Earth, is homogeneous and 2.24 epsilon(182W) units more radiogenic than that of the bulk Earth, metal/silicate differentiation of the Earth occurred very early. The new W-isotope data constrain the mean time of terrestrial core formation to 34 million years after the start of solar system accretion. Early terrestrial core formation implies rapid terrestrial accretion, thus permitting formation of the Moon by giant impact while Hf-182 was still alive. This could explain why lunar W-isotopes are more radiogenic than the terrestrial value. Copyright (C) 2002 Elsevier Science Ltd.

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Two different doses of Ross River virus (1111) were fed to Ochlerotatus vigilax (Skuse), the primary coastal vector in Australia; and blood engorged females were held at different temperatures up to 35 d. After ingesting 10(4.3) CCID50/Mosquito, mosquitoes reared at 18 and 25degreesC (and held at the same temperature) had higher body remnant and head and salivary gland titers than those held at 32degreesC, although infection rates were comparable. At 18, 25, and 32degreesC, respectively, virus was first detected in the salivary glands on days 3, 2, and 3. Based on a previously demonstrated 98.7% concordance between salivary gland infection and transmission, the extrinsic incubation periods were estimated as 5, 4, and 3 d, respectively, for these three temperatures. When Oc. vigilax reared at 18, 25, or 32degreesC were fed a lower dosage of 10(3.3) CCID50 RR/mosquito, and assayed after 7 d extrinsic incubation at these (or combinations of these) temperatures, infection rates and titers were similar. However, by 14 d, infection rates and titers of those reared and held at 18 and 32degreesC were significantly higher and lower, respectively. However, this process was reversible when the moderate 25degreesC was involved, and intermediate infection rates and titers resulted. These data indicate that for the strains of RR and Oc. vigilax used, rearing temperature is unimportant to vector competence in the field, and that ambient temperature variations will modulate or enhance detectable infection rates only after 7 d: extrinsic incubation. Because of the short duration of extrinsic incubation, however, this will do little to influence RR epidemiology, because by this time some Oc. vigilax could be seeking their third blood meal, the latter two being infectious.