Avian cryptococcosis Malik, R.; Krockenberger, M. B.; Cross, G. ...
Medical mycology (Oxford),
2003, Letnik:
41, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Clinical and laboratory findings in 15 unreported cases of avian cryptococcosis from Australia were collated and contrasted with 11 cases recorded in the literature. Cryptococcusspecies produced ...localized invasive disease of the upper respiratory tract of captive parrots living in Australia. This resulted in signs referable to mycotic rhinitis or to involvement of structures contiguous with the nasal cavity, such as the beak, sinuses, choana, retrobulbar space and palate. Parrots of widely differing ages were affected and of the seven birds for which sex was determinable, six were male. Cryptococcus bacillisporus(formerly C. neoformansvar. gattii) accounted for four of five infections in which the species or variety was determinable, suggesting that exposure to eucalyptus material may be a predisposing factor. In these cases, Cryptococcusappeared to behave as a primary pathogen of immunocompetent hosts. One tissue specimen was available from an Australian racing pigeon with minimally invasive subcutaneous disease; immunohistology demonstrated a C. neoformansvar. grubii(formerly C. neoformansvar. neoformansserotype A) infection, presumably subsequent to traumatic inoculation of yeast cells into the subcutis. Two similar cases had been reported previously in pigeons domiciled in America. Data for parrots, one pigeon and other birds studied principally in America and Europe (and likely infected with C. neoformans) suggested a different pattern of disease, more suggestive of opportunistic infection of immunodeficient hosts. In this cohort of patients, the organism was not restricted to cool superficial sites such as the upper respiratory tract or subcutis. Instead, infections typically penetrated the lower respiratory tract or disseminated widely to a variety of internal organs. Finally, three captive North Island brown kiwis, one residing in Australia, the other two in New Zealand, died as a result of severe diffuse cryptococcal pneumonia (two cases) or widely disseminated disease (one case). C. bacillisporusstrains were isolated from all three cases, as reported previously for another kiwi with disseminated disease in New Zealand.
The Thin-TOF PET (TT-PET) project aims at the construction of a small-animal PET scanner based on silicon monolithic pixel sensors with 30ps time resolution for 511keV photons, equivalent to 100ps ...time resolution for minimum ionizing particles. Iterative image reconstruction on Monte-Carlo simulation shows that the scanner can produce high signal-to-noise ratio images with good spatial resolution throughout the whole field of view. The demonstrator chip, comprising a 3 × 10 pixel matrix and a 50ps binning TDC, was tested at the CERN SPS beam test facility. The demonstrator shows an efficiency greater than 99.9% and a time resolution for minimum ionizing particles of approximately 110ps.
Upgrade of the ATLAS tracker detector for high-luminosity LHC conditions requires novel approaches to the pixel sensor design. Tests of different pitch layouts represent significant part of the ATLAS ...upgrade program. Better momentum resolution and multiple track reconstruction in the r–ϕ plane could be achieved with finer ϕ-segmentation. Changing the pitch from 50×250μm2 to 25×500μm2 in the outer pixel modules would improve the tracking performance of the upgraded ATLAS detector. The pixel sensors with 25×500μm2 readout by FE-I4 chips have been designed at the University of Liverpool. The sensors were measured in the laboratory and test-beam. Results of these tests will be presented together with geometry characteristics of other novel pixel layouts, compatible with the FE-I4 floor-plan, which have been designed and produced.
The aim of the CERN/RD50 collaboration is the improvement of the radiation tolerance of semiconductor detectors for future experiments at high-luminosity colliders. In the RD50 framework, evidence of ...enhanced signal charge in severely irradiated silicon detectors (diodes, segmented planar and 3D devices) was found. The underlying mechanism was labelled charge multiplication. This has been one of the most exciting results from the research activity of RD50 because it could allow for a greatly extended radiation tolerance, if the mechanism is to be found controllable and tuneable. The charge multiplication mechanism is governed by impact ionisation from electrons drifting in high electric field. The electric field profile is influenced by the geometry of the implanted electrodes. In order to investigate the influence of the diode implantation geometry on charge multiplication, the RD50 collaboration has commissioned the production of miniature microstrip silicon sensors with various choices of strip pitch and strip width over pitch (w/p) ratios. Moreover, some of the sensors were produced interleaving readout strips with dummy intermediate ones in order to modify the electric field profile. These geometrical solutions can influence both charge multiplication and charge sharing between adjacent strips. The initial results of this study are here presented.
A 3‐year‐old Maltese‐cross dog presented with a 4‐month history of chronic diarrhoea and inappetence. Poorly regenerative anaemia, leukocytosis and hypoproteinaemia were evident on several occasions. ...Biopsies of stomach, duodenum and colon revealed marked infiltration of mucosae by macrophages containing many acid‐fast bacilli. Similar organisms were numerous in a faecal smear. Melaena, haematochezia and severe abdominal pain developed and were unresponsive to therapy. Following euthanasia and necropsy, histiocytic cells containing acid‐fast bacilli were found throughout the gastrointestinal tract, mesenteric and peripheral lymph nodes, spleen, liver, kidney and lungs. The organism was identified as Mycobacterium avium by bacterial culture and polymerase chain reaction testing.
Two cases of fatal cryptococcosis are described, one of Cryptococcus neoformans infection in a Gilbert's potoroo (Potorous gilbertii) and one of Cryptococcus gattii infection in a long-nosed potoroo ...(Potorous tridactylus). The diagnoses were confirmed by culture and specific immunohistochemistry, respectively. The long-nosed potoroo tested positive using the latex cryptococcal antigen test (LCAT), whereas the Gilbert's potoroo had a negative LCAT result despite having advanced disease of some duration. In both cases, the clinical presentation was a progressive neurologic disease associated with a central nervous system infection. Pulmonary infection was also observed in the long-nosed potoroo. Specific treatment with antifungal agents was unsuccessful in the long-nosed potoroo.
Medical grade titanium samples were examined using X-ray photoelectron spectroscopy before and after immersion in various proteins. Additionally, an implant removed from a patient following clinical ...failure was examined using scanning ion and electron microscopy. The surface of the as-received samples was found to be mainly TiO2, with contaminants of H2O/OH-, calcium and nitrogen which remained after autoclaving. The immersed proteins adhered to the titanium surface, possibly via a Ca-O link. The failed clinical sample was found to be partially fibrously encapsulated with evidence of calcification. Small amounts of TiOOH were detected at the fibrous periphery, supporting the theory of Tengvall and co-workers that in vivo titanium implants are covered in a gel of this material.
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