HOXA/PBX3 knockdown impairs growth and sensitizes cytogenetically normal acute myeloid leukemia cells to chemotherapy

The cytogenetically normal subtype of acute myeloid leukemia (CN-AML) is associated with Intermediate risk which complicates therapeutic options. Lower overall HOX/TALE expression appears to correlate with more favorable prognosis/better response to treatment in some leukemias and solid cancer. The functional significance of the associated gene expression and response to chemotherapy is not known. Three independent microarray datasets obtained from large patient cohorts along with quantitative PCR validation was used to identify a four gene HOXA/TALE signature capable of prognostic stratification. Biochemical analysis was used to identify interactions between the four encoded proteins and targeted knockdown used to examine the functional importance of sustained expression of the signature in leukemia maintenance and response to chemotherapy. An eleven HOXA/TALE code identified in an Intermediate risk (n=315) compared to a Favourable group of patients (n=105) was reduced to a four gene signature of HOXA6, HOXA9, PBX3 and MEIS1 by iterative analysis of independent platforms. This signature maintained the Favorable/Intermediate risk partition and where applicable, correlated with overall survival in CN-AML. We further show that cell growth and function is dependent on maintained levels of these core genes and that direct targeting of HOXA/PBX3 sensitizes CN-AML cells to standard chemotherapy. Together the data support a key role for HOXA/TALE in CN-AML and demonstrate that targeting of clinically significant HOXA/PBX3 elements may provide therapeutic benefit to these patients.

Atmospheric pressure, nonthermal plasma inactivation of MS2 bacteriophage: effect of oxygen concentration on virucidal activity

AimsThe main aim of this study was to determine the virucidal inactivation efficacy of an in-house-designed atmospheric pressure, nonthermal plasma jet operated at varying helium/oxygen feed gas concentrations against MS2 bacteriophage, widely employed as a convenient surrogate for human norovirus.

Methods and ResultsThe effect of variation of percentage oxygen concentration in the helium (He) carrier gas was studied and found to positively correlate with MS2 inactivation rate, indicating a role for reactive oxygen species (ROS) in viral inactivation. The inactivation rate constant increased with increasing oxygen concentrations up to 075% O-2. 3 log(10) (999%) reductions in MS2 viability were achieved after 3min of exposure to the plasma source operated in a helium/oxygen (9925%:075%) gas mixture, with >7 log(10) reduction after 9min exposure.

ConclusionsAtmospheric pressure, nonthermal plasmas may have utility in the rapid disinfection of virally contaminated surfaces for infection control applications.

Significance and Impact of StudyThe atmospheric pressure, nonthermal plasma jet employed in this study exhibits rapid virucidal activity against a norovirus surrogate virus, the MS2 bacteriophage, which is superior to previously published inactivation rates for chemical disinfectants.

UDP-galactose 4-epimerase (GALE)

UDP-galactose 4-epimerase (GALE; EC 5.1.3.2; UniProt: Q14376) catalyses the interconversion of UDP-galactose and UDP-glucose (figure 1a). In the majority of eukaryotes studied to date, the enzyme is also able to interconvert UDP-N-acetylgalactosamine (UDP-GalNAc) and UDP-N-acetylglucosamine (UDP-GlcNAc) (figure 1b). The first of these reactions occurs as part of the Leloir pathway, which converts galactose into the glycolytic intermediate glucose 6-phosphate. Both reactions are important in the maintenance of UDP-monosaccharide pools and, consequently, in supplying raw materials for the glycosylation of proteins and lipids. The enzyme has attracted considerable research interest because mutations in the corresponding gene are associated with the genetic disease type III galactosemia (OMIN #230350). There is also some interest in using the enzyme as a biocatalyst to interconvert its substrates and related UDP-monosaccharides.

Potential Cellular Targets and Antibacterial Efficacy of Atmospheric Pressure Non-Thermal Plasma

Atmospheric pressure non-thermal plasma (APNTP) has been gaining increasing interest as a new alternative antibacterial approach. Although this approach has demonstrated promising antibacterial activity, its exact mechanism of action remains unclear. Mechanistic elucidation of the antimicrobial activity will facilitate development and rational optimisation of this approach for potential medical applications. In this study, the antibacterial efficacy of an in-house-built APNTP jet was evaluated alongside an investigation of the interactions between APNTP and major cellular components in order to identify the potential cellular targets involved in plasma-mediated bacterial destruction mechanisms. The investigated plasma jet exhibited excellent, rapid antibacterial activity against a selected panel of clinically significant bacterial species including Bacillus cereus, meticillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Pseudomonas aeruginosa, all of which were completely inactivated within 2 min of plasma exposure. Plasma-mediated damaging effects were observed, to varying degrees, on all of the investigated cellular components including DNA, a model protein enzyme, and lipid membrane integrity and permeability. The antibacterial efficacy of APNTP appears to involve a multiple-target mechanism, which potentially reduces the likelihood of emergence of microbial resistance towards this promising antimicrobial approach. However, cellular membrane damage and resulting permeability perturbation was found to be the most likely rate-determining step in this mechanism. Crown Copyright © 2013.

Histone deacetylase 3 unconventional splicing mediates endothelial-to- mesenchymal transition through transforming growth factor β2

Histone deacetylase 3 (HDAC3) plays a critical role in the maintenance of endothelial integrity and other physiological processes. In this study, we demonstrated that HDAC3 undergoes unconventional splicing during stem cell differentiation. Four different splicing variants have been identified, designated as HD3α, -β, -γ, and -Δ, respectively. HD3α was confirmed in stem cell differentiation by specific antibody against the sequences from intron 12. Immunofluorescence staining indicated that the HD3α isoform co-localized with CD31-positive or α-smooth muscle actin-positive cells at different developmental stages of mouse embryos. Overexpression of HD3α reprogrammed human aortic endothelial cells into mesenchymal cells featuring an endothelial-to-mesenchymal transition (EndMT) phenotype. HD3α directly interacts with HDAC3 and Akt1 and selectively activates transforming growth factor β2 (TGFβ2) secretion and cleavage. TGFβ2 functioned as an autocrine and/or paracrine EndMT factor. The HD3α-induced EndMT was both PI3K/Akt- and TGFβ2-dependent. This study provides the first evidence of the role of HDAC3 splicing in the maintenance of endothelial integrity.

Monitoring daily MLC positional errors using trajectory log files and EPID measurements for IMRT and VMAT deliveries

This work investigated the differences between multileaf collimator (MLC) positioning accuracy determined using either log files or electronic portal imaging devices (EPID) and then assessed the possibility of reducing patient specific quality control (QC) via phantom-less methodologies. In-house software was developed, and validated, to track MLC positional accuracy with the rotational and static gantry picket fence tests using an integrated electronic portal image. This software was used to monitor MLC daily performance over a 1 year period for two Varian TrueBeam linear accelerators, with the results directly compared with MLC positions determined using leaf trajectory log files. This software was validated by introducing known shifts and collimator errors. Skewness of the MLCs was found to be 0.03 ± 0.06° (mean ±1 standard deviation (SD)) and was dependent on whether the collimator was rotated manually or automatically. Trajectory log files, analysed using in-house software, showed average MLC positioning errors with a magnitude of 0.004 ± 0.003 mm (rotational) and 0.004 ± 0.011 mm (static) across two TrueBeam units over 1 year (mean ±1 SD). These ranges, as indicated by the SD, were lower than the related average MLC positioning errors of 0.000 ± 0.025 mm (rotational) and 0.000 ± 0.039 mm (static) that were obtained using the in-house EPID based software. The range of EPID measured MLC positional errors was larger due to the inherent uncertainties of the procedure. Over the duration of the study, multiple MLC positional errors were detected using the EPID based software but these same errors were not detected using the trajectory log files. This work shows the importance of increasing linac specific QC when phantom-less methodologies, such as the use of log files, are used to reduce patient specific QC. Tolerances of 0.25 mm have been created for the MLC positional errors using the EPID-based automated picket fence test. The software allows diagnosis of any specific leaf that needs repair and gives an indication as to the course of action that is required.

Housing booms and media coverage

This article analyses news media coverage of the housing market. Building on theories of media influence where word of mouth is the final mechanism of opinion change but media initiate discourse, I examine the relationship between news media and the recent UK house price boom. Over 30 000 articles on the UK housing market from the period 1993 to 2008 are analysed, and it is found that media Granger-caused real house price changes, suggesting the media may have influenced opinions on the housing market. However, media sentiment on the housing market did not change with the secular increase in house prices in the 2000s, suggesting that the media did not contribute to the UK’s housing boom and may have helped constrain it.

Structure and thermal properties of salicylate-based-protic ionic liquids as new heat storage media. COSMO-RS structure characterization and modeling of heat capacities

During this research, we present a study on the thermal properties, such as the melting, cold crystallization, and glass transition temperatures as well as heat capacities from 293.15 K to 323.15 K of nine in-house synthesized protic ionic liquids based on the 3-(alkoxymethyl)-1H-imidazol-3-ium salicylate ([H-Im-C₁OC_n][Sal]) with n = 3–11. The 3D structures, surface charge distributions and COSMO volumes of all investigated ions are obtained by combining DFT calculations and the COSMO-RS methodology. The heat capacity data sets as a function of temperature of the 3-(alkoxymethyl)-1H-imidazol-3-ium salicylate are then predicted using the methodology originally proposed in the case of ionic liquids by Ge et al. 3-(Alkoxymethyl)-1H-imidazol-3-ium salicylate based ionic liquids present specific heat capacities higher in many cases than other ionic liquids that make them suitable as heat storage media and in heat transfer processes. It was found experimentally that the heat capacity increases linearly with increasing alkyl chain length of the alkoxymethyl group of 3-(alkoxymethyl)-1H-imidazol-3-ium salicylate as was expected and predicted using the Ge et al. method with an overall relative absolute deviation close to 3.2% for temperatures up to 323.15 K.

IMRT for image-guided single vocal cord irradiation

PURPOSE: We have been developing an image-guided single vocal cord irradiation technique to treat patients with stage T1a glottic carcinoma. In the present study, we compared the dose coverage to the affected vocal cord and the dose delivered to the organs at risk using conventional, intensity-modulated radiotherapy (IMRT) coplanar, and IMRT non-coplanar techniques.

METHODS AND MATERIALS: For 10 patients, conventional treatment plans using two laterally opposed wedged 6-MV photon beams were calculated in XiO (Elekta-CMS treatment planning system). An in-house IMRT/beam angle optimization algorithm was used to obtain the coplanar and non-coplanar optimized beam angles. Using these angles, the IMRT plans were generated in Monaco (IMRT treatment planning system, Elekta-CMS) with the implemented Monte Carlo dose calculation algorithm. The organs at risk included the contralateral vocal cord, arytenoids, swallowing muscles, carotid arteries, and spinal cord. The prescription dose was 66 Gy in 33 fractions.

RESULTS: For the conventional plans and coplanar and non-coplanar IMRT plans, the population-averaged mean dose ± standard deviation to the planning target volume was 67 ± 1 Gy. The contralateral vocal cord dose was reduced from 66 ± 1 Gy in the conventional plans to 39 ± 8 Gy and 36 ± 6 Gy in the coplanar and non-coplanar IMRT plans, respectively. IMRT consistently reduced the doses to the other organs at risk.

CONCLUSIONS: Single vocal cord irradiation with IMRT resulted in good target coverage and provided significant sparing of the critical structures. This has the potential to improve the quality-of-life outcomes after RT and maintain the same local control rates.

Conjugate Heat Transfer Analysis of an Internally Cooled Gas Turbine Vane

A conjugate heat transfer (CHT) method was used to perform the aerothermal analysis of an internally cooled turbine vane, and was validated against experimental and empirical data.
Firstly, validation of the method with regard to internal cooling was done by reproducing heat transfer test data in a channel with pin fin heat augmenters, under steady constant wall temperature. The computed Nusselt numbers for the two tested configurations (full length circular pin fins attached to both walls and partial pin fins attached to one wall only) showed good agreement with the measurements. Sensitivity to mesh density was evaluated under this simplified case in order to establish mesh requirements for the analysis of the full component.
Secondly, the CHT method was applied onto a turbine vane test case from an actual engine. The predicted vane airfoil metal temperature was compared to the measured thermal paint data and the in-house empirical predictions. The CHT results agreed well with the thermal paint data and showed better prediction than the current empirical modeling approach.

Does chemical composition of individual Scots pine trees determine the biodiversity of their associated ground vegetation?

Despite plant secondary metabolites being major determinants of species interactions and ecosystem processes, their role in the maintenance of biodiversity has received little attention. In order to investigate the relationship between chemical and biological diversity in a natural ecosystem, we considered the impact of chemical diversity in individual Scots pine trees (Pinus sylvestris) on species richness of associated ground vegetation. Scots pine trees show substantial genetically determined constitutive variation between individuals in concentrations of a group of secondary metabolites, the monoterpenes. When the monoterpenes of particular trees were assessed individually, there was no relationship with species richness of associated ground flora. However, the chemical diversity of monoterpenes of individual trees was significantly positively associated with the species richness of the ground vegetation beneath each tree, mainly the result of an effect among the non-woody vascular plants. This correlation suggests that the chemical diversity of the ecosystem dominant species has an important role in shaping the biodiversity of the associated plant community. The extent and significance of this effect, and its underlying processes require further investigation.

Melt Processing and Properties of Polyamide 6/Graphene Nanoplatelet Composites

In this paper, the processing and characterization of Polyamide 6 (PA6) / graphite nanoplatelets
(GNPs) composites is reported. PA6/GNPs composites were prepared by melt-mixing using an
industrial, co-rotating, intermeshing, twin-screw extruder. A bespoke screw configuration was used
that was designed in-house to enhance nanoparticle dispersion into a polymer matrix. The effects of
GNPs type (xGnP® M-5 and xGnP® C-500), GNPs content, and extruder screw speed on the bulk
properties of the PA6/GNPs nanocomposites were investigated. Results show a considerable
improvement in the thermal and mechanical properties of PA6/GNPs composites, as compared with
the unfilled PA6 polymer. An increase in crystallinity (%Xc) with increasing GNPs content, and a
change in shape of the crystallization exotherms (broadening) and melting endotherms, both suggest a
change in the crystal type and perfection. An increase in tensile modulus of as much as 376% and
412% was observed for PA6/M-5 xGnP® and PA6/C-500 xGnP® composites, respectively, at filler
contents of 20wt%. The enhancement of Young’s modulus and yield stress can be attributed to the
reinforcing effect of GNPs and their uniform dispersion in the PA6 matrix. The rheological response
of the composite resembles that of a ‘pseudo-solid’, rather than a molten liquid, and analysis of the
rheological data indicates that a percolation threshold was reached at GNPs contents of between 10–
15wt%. The electrical conductivity of the composite also increased with increasing GNPs content,
with an addition of 15wt% GNPs resulting in a 6 order-of-magnitude increase in conductivity. The
electrical percolation thresholds of all composites were between 10–15wt%.

Characterisation of melt processed nanocomposites of Polyamide 6 subjected to uniaxial-drawing

In this paper, the processing and characterization of Polyamide 6 (PA6) nanocomposites containing graphite nanoplatelets (GNPs) is reported. PA6 nanocomposites were prepared by melt-mixing using an industrial, co-rotating, intermeshing, twin-screw extruder. A bespoke screw configuration was used that was designed in-house to enhance nanoparticle dispersion into a polymer matrix. The effects of nano-filler type (xGnPTM M-5 and xGnPTM C-500), nano-filler content, and extruder screw speed on the bulk properties of the PA6 nanocomposites were investigated. The crystalline structures of PA6 nanocomposites are related to thermal treatment, stress history and the presence of moisture and nanofillers. DSC, Raman and XRD studies show an increase in crystallinity with increasing GNP content and a phase transformation between α-form to γ-form crystals as a result of the heterophase nucleation effect. The effect of uniaxial stretching on PA6 nanocomposites was investigated by drawing specimens heated at temperatures below the melting temperature. DSC and Raman studies on the drawn samples show an increase in yield stress as the GNP content increases due to the strain induced crystallization and γ—β transition during stretching. The rheological response of the nanocomposites resemble that of a ‘pseudo-solid’, rather than a molten liquid, and analysis of the rheological data indicates that a percolation threshold was reached at GNP contents of between 10–15wt%. An increase in tensile modulus of as much as 412% was observed for PA6/C-500 xGnPTM composites, at a filler content of 20wt%. The enhancement of Young’s modulus and yield stress can be attributed to the reinforcing effect of GNPs and their uniform dispersion in the PA6 matrix. The electrical conductivity of the composite also increased with increasing GNP content, with an addition of 15wt% GNP resulting in a 6 order-of-magnitude increase in conductivity. The effects of uniaxial-drawing and the inclusion of multiple nano-filler varieties on the electrical and mechanical properties are currently under investigation.