Natural killer cells in acute myeloid leukemia patients: from phenotype to transcriptomic analysis.

Chemotherapies allow complete remission in more than 50 % of patients with acute myeloid leukemia (AML), however, with frequent relapse. This suggests that residual leukemic cells may escape to chemotherapy and immune system. Natural killer (NK) cells from AML patients (AML-NK) have a weaker natural cytotoxicity-activating receptors (NCRs) expression than NK cells from healthy donors (HD-NK). Coding genes for NCR1/NKp46, NCR2/NKp44 and NCR3/NKp30 are located at different loci on two different chromosomes; however, their expression is tightly coordinated. Most NK cells express either high (NCRbright) or low levels (NCRdull) of all three NCRs. This suggests the existence of negative/positive regulation factor(s) common to the three receptors. In order to find transcription factor(s) or pathway(s) involved in NCRs co-regulation, this study compared the transcriptomic signature of HD-NK and AML-NK cells, before and after in vitro NK cells culture. Microarrays analysis revealed a specific NK cells transcriptomic signature in patients with AML. However, in vitro NK cells expansion erased this signature and up-regulated expression of central molecules of NK functions, such as NCR, NKG2D and also ETS-1, regardless of their origin, i.e., AML-NK vs HD-NK. ETS-1 transcription factor was shown to bind to a specific and common region in the NCRs promoters, thus appearing as a good candidate to explain the coordinated regulation of three NCRs. Such results are encouraging regarding in vitro AML-NK cytotoxicity restoration and provide a new conceptual support for innovative cellular therapy based on in vitro NK cells expansion before their reinfusion in AML patients.

Correlation between surface chemistry and settlement behaviour in barnacle cyprids (Balanus improvisus).

In laboratory-based biofouling assays, the influence of physico-chemical surface characteristics on barnacle settlement has been tested most frequently using the model organism Balanus amphitrite (= Amphibalanus amphitrite). Very few studies have addressed the settlement preferences of other barnacle species, such as Balanus improvisus (= Amphibalanus improvisus). This study aimed to unravel the effects of surface physico-chemical cues, in particular surface-free energy (SFE) and surface charge, on the settlement of cyprids of B. improvisus. The use of well-defined surfaces under controlled conditions further facilitates comparison of the results with recent similar data for B. amphitrite. Zero-day-old cyprids of B. improvisus were exposed to a series of model surfaces, namely self-assembled monolayers (SAMs) of alkanethiols with varying end-groups, homogenously applied to gold-coated polystyrene (PS) Petri dishes. As with B. amphitrite, settlement of cyprids of B. improvisus was influenced by both SFE and charge, with higher settlement on low-energy (hydrophobic) surfaces and negatively charged SAMs. Positively charged SAMs resulted in low settlement, with intermediate settlement on neutral SAMs of similar SFE. In conclusion, it is demonstrated that despite previous suggestions to the contrary, these two species of barnacle show similar preferences in response to SFE; they also respond similarly to charge. These findings have positive implications for the development of novel antifouling (AF) coatings and support the importance of consistency in substratum choice for assays designed to compare surface preferences of fouling organisms.

Three dimensional tracking of exploratory behavior of barnacle cyprids using stereoscopy.

Surface exploration is a key step in the colonization of surfaces by sessile marine biofoulers. As many biofouling organisms can delay settlement until a suitable surface is encountered, colonization can comprise surface exploration and intermittent swimming. As such, the process is best followed in three dimensions. Here we present a low-cost transportable stereoscopic system consisting of two consumer camcorders. We apply this novel apparatus to behavioral analysis of barnacle larvae (≈800 µm length) during surface exploration and extract and analyze the three-dimensional patterns of movement. The resolution of the system and the accuracy of position determination are characterized. As a first practical result, three-dimensional swimming trajectories of the cypris larva of the barnacle Semibalanus balanoides are recorded in the vicinity of a glass surface and close to PEG2000-OH and C(11)NMe(3)(+)Cl(-) terminated self-assembled monolayers. Although less frequently used in biofouling experiments due to its short reproductive season, the selected model species [Marechal and Hellio (2011), Int Biodeterior Biodegrad, 65(1):92-101] has been used following a number of recent investigations on the settlement behavior on chemically different surfaces [Aldred et al. (2011), ACS Appl Mater Interfaces, 3(6):2085-2091]. Experiments were scheduled to match the availability of cyprids off the north east coast of England so that natural material could be used. In order to demonstrate the biological applicability of the system, analysis of parameters such as swimming direction, swimming velocity and swimming angle are performed.

Monitoring the air quality around an oil refinery through the use of diffusive sampling.

Diffusive sampling has been used to study the spatial distribution of SO(2), NO(2), NO(x), NH(3) and BTX (benzene, toluene and xylenes) near an oil refinery located in Falconara, Italy, over the period from March to October 2001. Three different categories of sampling sites (roadside, residential and background) were studied. In total, 56 sites were monitored. The results were evaluated on the basis of the limit values found in the European Directives. The results of the defined study indicate that the measured concentrations were substantially lower than the ambient air quality standard with the maximum concentrations being generally found much closer to emission sources. The monitoring method described here can be used to assess integrated concentration levels over long periods of time and to identify pollution "hotspots" where concentrations are likely to be consistently high. Identification of these hotspots may help to assess air quality and to implement proper action plans, especially in locations where industrial and urban pollution coexist.

Laboratory development and field evaluation of a new diffusive sampler to collect nitrogen oxides in the ambient air.

Diffusive samplers for the determination of NO(x) and NO2 based on collection on a coated carbon paper filter have been developed. NO is first oxidized to NO2 and then collected on the reactive surface. When NO2 and NOx samplers are exposed simultaneously, NO can be calculated by difference. The sampler has been derived from a Palmes design as recently modified by Bertoni et al. for the determination of BTX (benzene, toluene, xylenes). Laboratory tests were conducted in controlled atmosphere to evaluate linearity, uptake rate, face velocity effects, sample stability, influence of relative humidity, precision and accuracy. The samplers are capable of reliable measurements of the two species at common levels of a polluted atmosphere in urban settings yielding average concentration levels over 1 month and beyond. The uptake rate of NO2 was found to be 11.7 mL/min in a very good agreement (within 5%) with the value calculated from theory. The measured uptake rate for NO(x) was determined in experiments involving sampling at different concentration levels in comparison to chemiluminescence (CL) measurements. The precision of the measurements for co-located passive samplers was better than 5%. The accuracy of the data collected is within +/-20% of the actual value measured by CL. The laboratory and field results show that the NO(x) and NO2 samplers meet the data quality goal requested by the first EU Directive 1999/30/EU for these pollutants.

Monitoring of atmospheric pollutants by passive sampling for the protection of historic buildings and monuments.

When considering the various possibilities to assess the effects of SO2 and NO2 on historic buildings and monuments, a distinction can be made according to the completeness of the scope of the assessment itself. A first approach can be limited to gathering data as they become available through the official bodies established under air quality legislation. This approach is based on a single point measurement where a "general purpose" monitoring station is located, often quite far from the monument to protect and often without investigating local and temporal variations. A more comprehensive assessment should include a generalisation that covers the territory. This can be made on the basis of the knowledge of the spatial distribution of concentrations and the knowledge of the causes of air pollution. Passive samplers allow the measurement of air quality in numerous sites and to assess the pollutant spatial distribution over a large area with a high resolution. As an application of the method, the spatial distribution of SO2 and NO2 in the city of Siracusa, Sicily, Italy, has been studied to identify areas of high deposition fluxes in relation to the protection of buildings and monuments of the historic centre.