Epidemiology of invasive fungal diseases among patients with haematological disorders in the Asia-Pacific: a prospective observational study

AbstractWe conducted a 2-year multicentre prospective observational study to determine the epidemiology of and mortality associated with invasive fungal diseases (IFDs) among patients with haematological disorders in Asia. Eleven institutions from 8 countries/regions participated, with 412 subjects (28.2% possible, 38.3% probable and 33.5% proven IFDs) recruited. The epidemiology of IFDs in participating institutions was similar to Western centres, with Aspergillus spp. (65.9%) or Candida spp. (26.7%) causing the majority of probable and proven IFDs. The overall 30-day mortality was 22.1%. Progressive haematological disorder (odds ratio [OR] 5.192), invasive candidiasis (OR 3.679), and chronic renal disease (OR 6.677) were independently associated with mortality

Conductivity in quasi two-dimensional systems

The conductivity in quasi two-dimensional systems is calculated using the quantum kinetic equation. Linearizing the Lenard-Balescu collision integral with the extension to include external field dependences allows one to calculate the conductivity with diagrams beyond the GW approximation including maximally crossed lines. Consequently the weak localization correction as an interference effect appears here from the field dependence of the collision integral (the latter dependence sometimes called intra-collisional field effect). It is shown that this weak localization correction has the same origin as the Debye-Onsager relaxation effect in plasma physics. The approximation is applied to a system of quasi two-dimensional electrons in hetero-junctions which interact with charged and neutral impurities and the low temperature correction to the conductivity is calculated analytically. It turns out that the dynamical screening due to charged impurities leads to a linear temperature dependence, while the scattering from neutral impurities leads to the usual Fermi-liquid behavior. By considering an appropriate mass action law to determine the ratio of charged to neutral impurities we can describe the experimental metal-insulator transition at low temperatures as a Mott-Hubbard transition.Comment: 7 pages 7 pages appendix 11 figure

Natural killer cell malignancies: clinicopathologic and molecular features

Malignancies of natural killer (NK) cells h ave increasingly been recognized as distinct clinicopathological entities. The tumor cells are characterized by an immunophenotype of CD2+, surface CD3-, cytoplasmic CD3e+, and CD56+. The T cell receptor gene is in germline configuration, and a consistent association with Epstein-Barr virus is demonstrable. Pa t h o l o g i c a l l y, the tumor cells show variable cytological appearances, with frequent angioinvasion and angiocentricity associated with zonal necrosis. Clinically, most cases affect the nasal cavity or other parts of the upper aerodigestive tract, and are referred to as nasal NK cell lymphoma. A minority involve extranasal sites such as the skin, gastrointestinal tract and testis, and are often referred to as ex t r a n a s a l NK cell lymphoma. A particularly aggressive form presents fulminantly as disseminated disease, sometimes with a leukemic phase, and is referred to as aggressive NK cell lymphoma/leukemia. Cytogenetic and molecular analysis have shown DNA losses at chromosomes 6q, 11q, 13q and 17p to be recurrent aberrations in NK cell malignancies. Frequent DNA gains are also found in chromosomes 1p, 6p, 11q, 12q, 17q, 19p, 20q, and Xp. These regions of DNA losses and gains should be targets for further inve s t i gation in order to understand the molecular pathogenesis of this lymphoma. Finally, optimal treatment modalities need to be determined, as all subtypes of NK cell malignancies are associated with a poor prognosis