Synthesis and characterization of polymer networks and star polymers containing a novel, hydrolyzable acetal-based dimethacrylate cross-linker

An acid-labile dimethaerylate acetal cross-linker,di(methacryloyloxy-l-ethoxy)methane(DMOEM), was synthesized by the reaction of 2-hydroxyethyl methacrylate and paraformaldehyde using p-toluenesulfonic acid and toluene as catalyst and solvent, respectively. Group transfer polymerization was employed to use this cross-linker in the preparation of nine hydrolyzable polymer structures: one neat cross-linker network, one randomly cross-linked network of methyl methacrylate (MMA), and seven star-shaped polymers of MMA. Gel permeation chromatography (GPC) in tetrahydrofuran (THF) confirmed the narrow molecular weight distributions of the linear polymer precursors to the stars and demonstrated the increase in molecular weight upon the addition of cross-linker for the formation of star-shaped polymers. Characterization of the star polymers in THF using static light scattering and GPC showed that the molecular weights and the number of arms of each star polymer increased with an increase in the molar ratio of cross-linker to initiator and with a decrease in the molar ratio of monomer to initiator. The star polymers with DMOEM cores bore a smaller number of arms than those cross-linked with the non-hydrolyzable commercial cross-linker ethylene glycol dimethacrylate due to the bulkier structure of DMOEM. All DMOEM-containing polymer networks and star polymers were completely hydrolyzed within 48 h using hydrochloric acid in THF.

A phase II study of vorinostat (MK-0683) in patients with polycythaemia vera and essential thrombocythaemia

Inhibition of histone deacetylases may be an important target in patients with myeloproliferative neoplasms. This investigator-initiated, non-randomized, open-label phase II multi-centre study included 63 patients (19 essential thrombocythaemia, 44 polycythaemia vera) from 15 centres. The primary objective was to evaluate if vorinostat was followed by a decline in clonal myeloproliferation as defined by European Leukaemia Net. Thirty patients (48%) completed the intervention period (24 weeks of therapy). An intention-to-treat response rate of 35% was identified. Pruritus was resolved [19% to 0% (P = 0·06)] and the prevalence of splenomegaly was lowered from 50% to 27% (P = 0·03). Sixty-five per cent of the patients experienced a decrease in JAK2 V617F allele burden (P = 0·006). Thirty-three patients (52% of patients) discontinued study drug before end of intervention due to adverse events (28 patients) or lack of response (5 patients). In conclusion, vorinostat showed effectiveness by normalizing elevated leucocyte and platelet counts, resolving pruritus and significantly reducing splenomegaly. However, vorinostat was associated with significant side effects resulting in a high discontinuation rate. A lower dose of vorinostat in combination with conventional and/or novel targeted therapies may be warranted in future studies.

The addition of gemtuzumab ozogamicin to low-dose Ara-C improves remission rate but does not significantly prolong survival in older patients with acute myeloid leukaemia:results from the LRF AML14 and NCRI AML16 pick-a-winner comparison

The treatment of older patients with acute myeloid leukaemia, who are not considered suitable for conventional intensive therapy, is unsatisfactory. Low-dose Ara-C(LDAC) has been established as superior to best supportive care, but only benefits the few patients who enter complete remission. Alternative or additional treatments are required to improve the situation. This randomised trial compared the addition of the immunoconjugate, gemtuzumab ozogamicin (GO), at a dose of 5 mg on day 1 of each course of LDAC, with the intention of improving the remission rate and consequently survival. Between June 2004 and June 2010, 495 patients entered the randomisation. The addition of GO significantly improved the remission rate (30% vs 17%; odds ratio(OR) 0.48 (0.32-0.73); P=0.006), but not the 12 month overall survival (25% vs 27%). The reason for the induction benefit failing to improve OS was two-fold: survival of patients in the LDAC arm who did not enter remission and survival after relapse were both superior in the LDAC arm. Although the addition of GO to LDAC doubled the remission rate it did not improve overall survival. Maintaining remission in older patients remains elusive.

Investigating the Potential Impact of Four-dimensional Computed Tomography (4DCT) on Toxicity, Outcomes and Dose Escalation for Radical Lung Cancer Radiotherapy

AIMS: To investigate the potential dosimetric and clinical benefits predicted by using four-dimensional computed tomography (4DCT) compared with 3DCT in the planning of radical radiotherapy for non-small cell lung cancer.

MATERIALS AND METHODS:
Twenty patients were planned using free breathing 4DCT then retrospectively delineated on three-dimensional helical scan sets (3DCT). Beam arrangement and total dose (55 Gy in 20 fractions) were matched for 3D and 4D plans. Plans were compared for differences in planning target volume (PTV) geometrics and normal tissue complication probability (NTCP) for organs at risk using dose volume histograms. Tumour control probability and NTCP were modelled using the Lyman-Kutcher-Burman (LKB) model. This was compared with a predictive clinical algorithm (Maastro), which is based on patient characteristics, including: age, performance status, smoking history, lung function, tumour staging and concomitant chemotherapy, to predict survival and toxicity outcomes. Potential therapeutic gains were investigated by applying isotoxic dose escalation to both plans using constraints for mean lung dose (18 Gy), oesophageal maximum (70 Gy) and spinal cord maximum (48 Gy).

RESULTS:
4DCT based plans had lower PTV volumes, a lower dose to organs at risk and lower predicted NTCP rates on LKB modelling (P < 0.006). The clinical algorithm showed no difference for predicted 2-year survival and dyspnoea rates between the groups, but did predict for lower oesophageal toxicity with 4DCT plans (P = 0.001). There was no correlation between LKB modelling and the clinical algorithm for lung toxicity or survival. Dose escalation was possible in 15/20 cases, with a mean increase in dose by a factor of 1.19 (10.45 Gy) using 4DCT compared with 3DCT plans.

CONCLUSIONS:
4DCT can theoretically improve therapeutic ratio and dose escalation based on dosimetric parameters and mathematical modelling. However, when individual characteristics are incorporated, this gain may be less evident in terms of survival and dyspnoea rates. 4DCT allows potential for isotoxic dose escalation, which may lead to improved local control and better overall survival.

Validation of an ultra high performance liquid chromatography-tandem mass spectrometry method for detection and quantitation of 19 endocrine disruptors in milk

An endocrine disruptor (ED) is an exogenous compound that interferes with the body's endocrine system. Exposure to EDs may result in adverse health effects such as infertility and cancer. EDs are composed of a vast group of chemicals including compounds of natural origin such as phytoestrogens or mycotoxins and a wide range of man-made chemicals such as pesticides. Synthetic compounds may find their way into the food chain where a number of them can biomagnify. Additionally, processing activities and food contact materials may add further to the already existing pool of food contaminants. Thus, our diet is considered to be one of the main exposure routes to EDs. Some precautionary legislation has already been introduced to control production and/or application of some persistent organic pollutants with ED characteristics. However, newly emerging EDs with bioaccumulative properties have recently been reported to appear at lower tiers of the food chain but have not been monitored at the grander scale. Milk and dairy products are a major component of our diet, thus it is important to monitor them for EDs. However, most methods developed to date are devoted to one group of compounds at a time. The UHPLC-MS/MS method described here has been validated according to EC decision 2002/657/EC and allows simultaneous extraction, detection, quantitation and confirmation of 19 EDs in milk. The method calibration range is between 0.50 and 20.0 μg kg with coefficients of determination above 0.99 for all analytes. Precision varied from 4.7% to 23.4% in repeatability and reproducibility studies. Established CCα and CCβ values (0.11-0.67 μg kg) facilitate fast, reliable, quantitative and confirmatory analysis of sub μg kg levels of a range of EDs in milk.

Macrophage migration inhibitory factor contributes to the immune escape of ovarian cancer by down-regulating NKG2D

The proinflammatory cytokine macrophage migration inhibitory factor (MIF) stimulates tumor cell proliferation, migration, and metastasis; promotes tumor angiogenesis; suppresses p53-mediated apoptosis; and inhibits antitumor immunity by largely unknown mechanisms. We here describe an overexpression of MIF in ovarian cancer that correlates with malignancy and the presence of ascites. Functionally, we find that MIF may contribute to the immune escape of ovarian carcinoma by transcriptionally down-regulating NKG2D in vitro and in vivo which impairs NK cell cytotoxicity toward tumor cells. Together with the additional tumorigenic properties of MIF, this finding provides a rationale for novel small-molecule inhibitors of MIF to be used for the treatment of MIF-secreting cancers.

Simvastatin in the Acute Respiratory Distress Syndrome

Background

Studies in animals and in vitro and phase 2 studies in humans suggest that statins may be beneficial in the treatment of the acute respiratory distress syndrome (ARDS). This study tested the hypothesis that treatment with simvastatin would improve clinical outcomes in patients with ARDS.

Methods

In this multicenter, double-blind clinical trial, we randomly assigned (in a 1:1 ratio) patients with an onset of ARDS within the previous 48 hours to receive enteral simvastatin at a dose of 80 mg or placebo once daily for a maximum of 28 days. The primary outcome was the number of ventilator-free days to day 28. Secondary outcomes included the number of days free of nonpulmonary organ failure to day 28, mortality at 28 days, and safety.

Results

The study recruited 540 patients, with 259 patients assigned to simvastatin and 281 to placebo. The groups were well matched with respect to demographic and baseline physiological variables. There was no significant difference between the study groups in the mean (±SD) number of ventilator-free days (12.6±9.9 with simvastatin and 11.5±10.4 with placebo, P=0.21) or days free of nonpulmonary organ failure (19.4±11.1 and 17.8±11.7, respectively; P=0.11) or in mortality at 28 days (22.0% and 26.8%, respectively; P=0.23). There was no significant difference between the two groups in the incidence of serious adverse events related to the study drug.

Conclusions

Simvastatin therapy, although safe and associated with minimal adverse effects, did not improve clinical outcomes in patients with ARDS. (Funded by the U.K. National Institute for Health Research Efficacy and Mechanism Evaluation Programme and others; HARP-2 Current Controlled Trials number, ISRCTN88244364.)

Famine and land, 1845-80

While historians once tended to displace the Famine from a pivotal position in modern Irish history, more recent research emphasizes its centrality, and focuses upon the controversial issue of state responsibility. Mortality levels from the Famine place it, proportionately, as one of the most devastating recorded human catastrophes. Official British policy towards Ireland spanned two governments, those of Robert Peel and John Russell, with historians taking a more emollient view of the former: in fact there were significant continuities between the two. The legacy of the Famine was uneven, with commercial and technological advance and the consolidation of both the farming interest and landlordism. On the other hand, recent research emphasizes evidence of continuing economic uncertainty, particularly in the West, together with ongoing landlord-tenant tensions. Rural insecurities, crystallized by the poor harvests of 185964, underlay the post-Famine years, and fed into the politicization of the later 1870s.

Improved Thermal Performance of SOI Using Compound Buried Layer

The buried oxide (BOX) layer in silicon on insulator (SOI) was replaced by a compound buried layer (CBL) containing layers of SiO2, polycrystalline silicon (polysilicon), and SiO2. The undoped polysilicon in the CBL acted as a dielectric with a higher thermal conductivity than SiO2. CBL provides a reduced thermal resistance with the same equivalent oxide thickness as a standard SiO2 buried layer. Thermal resistance was further reduced by lateral heat flow through the polysilicon. Reduction in thermal resistance by up to 68% was observed, dependent on polysilicon thickness. CBL SOI substrates were designed and manufactured to achieve a 40% reduction in thermal resistance compared with an 1.0-μm SiO2 BOX. Power bipolar transistors with an active silicon layer thickness of 13.5 μm manufactured on CBL SOI substrates showed a 5%-17% reduction in thermal resistance compared with the standard SOI. This reduction was dependent on transistor layout geometry. Between 65% and 90% of the heat flow from these power transistors is laterally through the thick active silicon layer. Analysis confirmed that CBL SOI provided a 40% reduction in the vertical path thermal resistance. Devices employing thinner active silicon layers will achieve the greater benefit from reduction in vertical path thermal resistance offered by CBL SOI.

DC resistance and dielectric function at 3392 nm of YBCO films from 300 K to 80 K

The dielectric function of a YBCO film was determined at 3392nm at temperatures down to 80K. Results obtained were epsilon(i) = -24.09 - 0.0013T and epsilon(i) = 7.66 + 0.067T. The results for epsilon(i) are compared with the de resistance of the film. Intrinsic intragrain scattering, elastic and inelastic grain boundary scattering and optical interband absorption are estimated as 82%, 5%, 13% and 10% respecively at 0K.

Mechanisms of DNA Damage Response to Targeted Irradiation in Organotypic 3D Skin Cultures

DNA damage (caused by direct cellular exposure and bystander signaling) and the complex pathways involved in its repair are critical events underpinning cellular and tissue response following radiation exposures. There are limited data addressing the dynamics of DNA damage induction and repair in the skin particularly in areas not directly exposed. Here we investigate the mechanisms regulating DNA damage, repair, intracellular signalling and their impact on premature differentiation and development of inflammatory-like response in the irradiated and surrounding areas of a 3D organotypic skin model. Following localized low-LET irradiation (225 kVp X-rays), low levels of 53BP1 foci were observed in the 3D model (3.8±0.28 foci/Gy/cell) with foci persisting and increasing in size up to 48 h post irradiation. In contrast, in cell monolayers 14.2±0.6 foci/Gy/cell and biphasic repair kinetics with repair completed before 24 h was observed. These differences are linked to differences in cellular status with variable level of p21 driving apoptotic signalling in 2D and accelerated differentiation in both the directly irradiated and bystander areas of the 3D model. The signalling pathways utilized by irradiated keratinocytes to induce DNA damage in non-exposed areas of the skin involved the NF-κB transcription factor and its downstream target COX-2.

Microstructure, properties and application of YAl2 intermetallic compound as particle reinforcements

An yttrium aluminum (YAl2) intermetallic compound ingot was prepared in an induction furnace under vacuum. The microstructure of YAl2 ingot was characterized by optical microscopy, scanning electron microscopy, and X-ray diffraction. The load bearing response of YAl2 intermetallic was investigated and compared with SiC ceramic by indentation combined with optical microscopy and scanning electron microscopy. Additionally, the tensile properties of the Mg–Li matrix composites reinforced with ultrafine YAl2 particles fabricated by planet ball milling were tested. The results show that the intermetallic compound ingot in this experiment is composed of a main face-centered-cubic structure YAl2 phase, a small amount of YAl phase, and minor Y and Al-rich phases. YAl2 intermetallic compound has excellent stability and shows better capability in crack resistance than SiC ceramic. The YAl2 intermetallic compound has better deformation compatibility with the Mg–14Li–3Al matrix than SiC reinforcement with the matrix, which leads to the superior resistance to crack for YAl2p/Mg–14Li–3Al composite compared to SiCp/Mg–14Li–3Al composite.

Electron recombination, photoionization, and scattering via many-electron compound resonances

Highly excited eigenstates of atoms and ions with open f shell are chaotic superpositions of thousands, or even millions, of Hartree-Fock determinant states. The interaction between dielectronic and multielectronic configurations leads to the broadening of dielectronic recombination resonances and relative enhancement of photon emission due to opening of thousands of radiative decay channels. The radiative yield is close to 100% for electron energy <1 eV and rapidly decreases for higher energies due to opening of many autoionization channels. The same mechanism predicts suppression of photoionization and relative enhancement of the Raman scattering. Results of our calculations of the recombination rate are in agreement with the experimental data for W20+ and Au25+.

A comparison of two informative SNP-based strategies for typing Pseudomonas aeruginosa isolates from patients with cystic fibrosis

BACKGROUND: Molecular typing is integral for identifying Pseudomonas aeruginosa strains that may be shared between patients with cystic fibrosis (CF). We conducted a side-by-side comparison of two P. aeruginosa genotyping methods utilising informative-single nucleotide polymorphism (SNP) methods; one targeting 10 P. aeruginosa SNPs and using real-time polymerase chain reaction technology (HRM10SNP) and the other targeting 20 SNPs and based on the Sequenom MassARRAY platform (iPLEX20SNP).

METHODS: An in-silico analysis of the 20 SNPs used for the iPLEX20SNP method was initially conducted using sequence type (ST) data on the P. aeruginosa PubMLST website. A total of 506 clinical isolates collected from patients attending 11 CF centres throughout Australia were then tested by both the HRM10SNP and iPLEX20SNP assays. Type-ability and discriminatory power of the methods, as well as their ability to identify commonly shared P. aeruginosa strains, were compared.

RESULTS: The in-silico analyses showed that the 1401 STs available on the PubMLST website could be divided into 927 different 20-SNP profiles (D-value = 0.999), and that most STs of national or international importance in CF could be distinguished either individually or as belonging to closely related single- or double-locus variant groups. When applied to the 506 clinical isolates, the iPLEX20SNP provided better discrimination over the HRM10SNP method with 147 different 20-SNP and 92 different 10-SNP profiles observed, respectively. For detecting the three most commonly shared Australian P. aeruginosa strains AUST-01, AUST-02 and AUST-06, the two methods were in agreement for 80/81 (98.8%), 48/49 (97.8%) and 11/12 (91.7%) isolates, respectively.

CONCLUSIONS: The iPLEX20SNP is a superior new method for broader SNP-based MLST-style investigations of P. aeruginosa. However, because of convenience and availability, the HRM10SNP method remains better suited for clinical microbiology laboratories that only utilise real-time PCR technology and where the main interest is detection of the most highly-prevalent P. aeruginosa CF strains within Australian clinics.