Adaptations of Natural Killer Cells to Self-MHC Class I.

Natural Killer (NK) cells use germ line encoded receptors to detect diseased host cells. Despite the invariant recognition structures, NK cells have a significant ability to adapt to their surroundings, such as the presence or absence of MHC class I molecules. It has been assumed that this adaptation occurs during NK cell development, but recent findings show that mature NK cells can also adapt to the presence or absence of MHC class I molecules. Here, we summarize how NK cells adjust to changes in the expression of MHC class I molecules. We propose an extension of existing models, in which MHC class I recognition during NK cell development sequentially instructs and maintains NK cell function. The elucidation of the molecular basis of the two effects may identify ways to improve the fitness of NK cells and to prevent the loss of NK cell function due to persistent alterations in their environment

Unusual forms of subacute invasive pulmonary aspergillosis in patients with solid tumors

Objectives: Aspergillus spp. can cause acute invasive disease in severely immuno-compromised patients. Nonetheless, there are few reports of solid tumors complicated with subacute invasive pulmonary aspergillosis (subacute IPA). Methods: Retrospective observational cohort study, performed in patients with primary lung cancer or secondary lung metastasis complicated with subacute IPA in three referral hospitals. Results: From 2008 to 2011, 14 episodes of subacute IPA were diagnosed, including 11 (78.6%) probable and 3 proven (21.4%). Nine patients (64.3%) had primary lung cancer. Thirteen patients (92.9%) had more than one local or systemic predisposing factor for subacute IPA. No patient had previous fungal colonization. Aspergillus spp. was isolated in 6 specimens of bronchoalveolar lavage, 6 sputum, 2 biopsies, and 1 percutaneous lung puncture. At the time Aspergillus spp. was isolated, the most common radiologic findings on chest computed tomography (CT) were cavitary masses, and development or expansion of cavitation in existing masses or nodules (10/14, 71.4%). On CT follow-up, most patients (8/12, 66.7%) had new cavity formation or expansion of one or more existing cavities. All patients were treated with azoles and two underwent surgery. Ten (71.4%) patients died after Aspergillus spp. was detected (median time 73 days, IQR 33-243): 2 (20%) deaths were subacute IPA-attributable and 6 (60%) were related. Conclusions: Primary lung cancer and secondary lung metastasis seem to be triggering factors for Aspergillus spp. implantation, and predispose to subacute IPA. Once localized in the damaged lung, the mold can grow and cause or expand cavities. In lung cancer patients, Aspergillus spp. detection is associated with a very poor prognosis. (C) 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved

Avantages et limites de l'intercalibration de méthodes d'évaluation phytoplanctoniques basée sur l'expérience des réservoirs du GIG méditerranéen

International audienceThe status of European legislation regarding inland water quality after the enactment of the Water Framework Directive (WFD) originated scientific effort to develop reliable methods, primarily based on biological parameters. An important aspect of the process was to ensure that quality assessment was comparable between the different Member States. The Intercalibration process (IC), required in the WFD ensures the unbiased application of the norm. The presented results were developed in the context of the 2nd IC phase. An overview of the reservoir type definition of the Lake Mediterranean Geographical Intercalibration Group, where four types were considered divided by both alkalinity and climate, together with the results for selection of Maximum Ecological Potential sites (MEP) are presented. MEP reservoirs were selected based on pressure and biological variables. Three phytoplankton-based assessment methods were intercalibrated using data from Mediterranean countries. The Mediterranean Assessment System for Reservoirs Phytoplankton (Spain), the New Mediterranean Assessment System for Reservoirs Phytoplankton (Portugal and Cyprus) and the New Italian Method (Italy) were applied. These three methods were compared through option 3 of the Intercalibration Guide. The similarity of the assessments was quantified, and the Good/Moderate (GM) boundaries assessed. All three methods stood as comparable at the GM boundary except for the MASRP in siliceous wet reservoirs, which was slightly stricter. Finally, the main taxonomic groups represented in the phytoplankton community at MEP conditions were identified, as well as their main changes with an increasing trophic status. MEP sites are dominated by chrysophytes in siliceous wet reservoirs and by the diatoms Cyclotella and Achnanthes in calcareous ones. Cyanobacteria take over the community in both calcareous and siliceous wet reservoirs as eutrophication increases. In summary, the relevance and reliability of the quality assessment methods compared were confirmed both from an ecological perspective and a health risk management point of view

Water Framework Directive Intercalibration Technical Report. Mediterranean Lake Phytoplankton ecological assessment methods

One of the key actions identified by the Water Framework Directive (WFD; 2000/60/EC) is to develop ecological assessment tools and carry out a European intercalibration (IC) exercise. The aim of the Intercalibration is to ensure that the values assigned by each Member State to the good ecological class boundaries are consistent with the Directive\u27s generic description of these boundaries and comparable to the boundaries proposed by other MS. In total, 83 lake assessment methods were submitted for the 2nd phase of the WFD intercalibration (2008-2012) and 62 intercalibrated and included in the EC Decision on Intercalibration (EC 2013). The intercalibration was carried out in the 13 Lake Geographical Intercalibration Groups according to the ecoregion and biological quality element. In this report we describe how the intercalibration exercise has been carried out in the Mediterranean Lake Phytoplankton group