eNOS overexpression exacerbates vascular closure in the obliterative phase of OIR and increases angiogenic drive in the subsequent proliferative stage

Purpose: In ischemic retinopathies, the misdirection of reparative angiogenesis away from the hypoxic retina leads to pathologic neovascularization. Thus, therapeutic strategies that reverse this trend would be extremely beneficial. Nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) is an important mediator of vascular endothelial growth factor (VEGF) function facilitating vascular growth and maturation. However, in addition to NO, eNOS can also produce superoxide (O), exacerbating pathology. Here, our aim was to investigate the effect of eNOS overexpression on vascular closure and subsequent recovery of the ischemic retina.

Methods: Mice overexpressing eNOS-GFP were subjected to oxygen-induced retinopathy (OIR) and changes in retinal vascularization quantified. Background angiogenic drive was assessed during vascular development and in aortic rings. NOS activity was measured by Griess assay or conversion of radiolabeled arginine to citrulline, nitrotyrosine (NT), and superoxide by immunolabeling and dihydroethidium fluorescence and VEGF by ELISA.

Results: In response to hyperoxia, enhanced eNOS expression led to increased NOS-derived superoxide and dysfunctional NO production, NT accumulation, and exacerbated vessel closure associated with tetrahydrobiopterin (BH) insufficiency. Despite worse vaso-obliteration, eNOS overexpression resulted in elevated hypoxia-induced angiogenic drive, independent of VEGF production. This correlated with increased vascular branching similar to that observed in isolated aortas and during development. Enhanced recovery was also associated with neovascular tuft formation, which showed defective NO production and increased eNOS-derived superoxide and NT levels.

Conclusions: In hyperoxia, reduced BH bioavailability causes overexpressed eNOS to become dysfunctional, exacerbating vaso-obliteration. In the proliferative phase, however, eNOS has important prorepair functions enhancing angiogenic growth potential and recovery in ischemia. © 2012 The Association for Research in Vision and Ophthalmology, Inc.

Posttranscriptional regulation of acute phase serum amyloid A2 expression by the 5'- and 3'-untranslated regions of its mRNA

Human acute-phase serum amyloid A protein (A-SAA) is a major acute phase reactant, the concentration of which increases dramatically as part of the body's early response to inflammation. A-SAA is the product of two almost identical genes, SAA1 and SAA2, which are induced by the pro-inflammatory cytokines, IL-1 and IL-6. In this study, we examine the roles played by the 5'- and 3'-untranslated regions (UTRs) of the SAA2 mRNA in regulating A-SAA2 expression. SAA2 promoter-driven luciferase reporter gene constructs carrying the SAA2 5'-UTR and/or 3'-UTR were transiently transfected into the HepG2 human hepatoma cell line. After induction of chimeric mRNA with IL-1beta and IL-6, the SAA2 5'- and 3'-UTRs were both able to posttranscriptionally modify the expression of the luciferase reporter. The SAA2 5'-UTR promotes efficient translation of the chimeric luciferase transcripts, whereas the SAA2 3'-UTR shares this property and also significantly accelerates the rate of reporter mRNA degradation. Our data strongly suggest that the SAA2 5'- and 3'-UTRs each play significant independent roles in the posttranscriptional regulation of A-SAA2 protein synthesis.

Ataxia-telangiectasia-mutated (ATM) and NBS1-dependent phosphorylation of Chk1 on Ser-317 in response to ionizing radiation

In mammals, the ATM (ataxia-telangiectasia-mutated) and ATR (ATM and Rad3-related) protein kinases function as critical regulators of the cellular DNA damage response. The checkpoint functions of ATR and ATM are mediated, in part, by a pair of checkpoint effector kinases termed Chk1 and Chk2. In mammalian cells, evidence has been presented that Chk1 is devoted to the ATR signaling pathway and is modified by ATR in response to replication inhibition and UV-induced damage, whereas Chk2 functions primarily through ATM in response to ionizing radiation (IR), suggesting that Chk2 and Chk1 might have evolved to channel the DNA damage signal from ATM and ATR, respectively. We demonstrate here that the ATR-Chk1 and ATM-Chk2 pathways are not parallel branches of the DNA damage response pathway but instead show a high degree of cross-talk and connectivity. ATM does in fact signal to Chk1 in response to IR. Phosphorylation of Chk1 on Ser-317 in response to IR is ATM-dependent. We also show that functional NBS1 is required for phosphorylation of Chk1, indicating that NBS1 might facilitate the access of Chk1 to ATM at the sites of DNA damage. Abrogation of Chk1 expression by RNA interference resulted in defects in IR-induced S and G(2)/M phase checkpoints; however, the overexpression of phosphorylation site mutant (S317A, S345A or S317A/S345A double mutant) Chk1 failed to interfere with these checkpoints. Surprisingly, the kinase-dead Chk1 (D130A) also failed to abrogate the S and G(2) checkpoint through any obvious dominant negative effect toward endogenous Chk1. Therefore, further studies will be required to assess the contribution made by phosphorylation events to Chk1 regulation. Overall, the data presented in the study challenge the model in which Chk1 only functions downstream from ATR and indicate that ATM does signal to Chk1. In addition, this study also demonstrates that Chk1 is essential for IR-induced inhibition of DNA synthesis and the G(2)/M checkpoint.

A Randomized, Double-Blind, Dose-Finding, Multicenter, Phase 2 Study of Radium Chloride (Ra 223) in Patients with Bone Metastases and Castration-Resistant Prostate Cancer

BACKGROUND: Patients with castration-resistant prostate cancer (CRPC) and bone metastases have an unmet clinical need for effective treatments that improve quality of life and survival with a favorable safety profile. OBJECTIVE: To prospectively evaluate the efficacy and safety of three different doses of radium chloride (Ra 223) in patients with CRPC and bone metastases. DESIGN, SETTING, AND PARTICIPANTS: In this phase 2 double-blind multicenter study, 122 patients were randomized to receive three injections of Ra 223 at 6-wk intervals, at doses of 25 kBq/kg (n=41), 50 kBq/kg (n=39), or 80 kBq/kg (n=42). The study compared the proportion of patients in each dose group who had a confirmed decrease of =50% in baseline prostate-specific antigen (PSA) levels. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Efficacy was evaluated using blood samples to measure PSA and other tumor markers, recorded skeletal-related events, and pain assessments. Safety was evaluated using adverse events (AEs), physical examination, and clinical laboratory tests. The Jonckheere-Terpstra test assessed trends between groups. RESULTS AND LIMITATIONS: The study met its primary end point with a statistically significant dose-response relationship in confirmed =50% PSA declines for no patients (0%) in the 25-kBq/kg dose group, two patients (6%) in the 50-kBq/kg dose group, and five patients (13%) in the 80-kBq/kg dose group (p=0.0297). A =50% decrease in bone alkaline phosphatase levels was identified in six patients (16%), 24 patients (67%), and 25 patients (66%) in the 25-, 50-, and 80-kBq/kg dose groups, respectively (p

A study of secondary instabilities in postbuckling composite aerostructures

A number of experimental studies have shown that postbuckling stiffened composite panels, loaded in uniaxial compression, may undergo secondary instabilities, characterised by an abrupt change in the buckled mode-shape of the skin between the supporting stiffeners. In this study high-speed digital speckle photogrammetry is used to gain further insight into an I-stiffened panel's response during this transient phase. This energy-dissipating phenomenon will be shown to be able to cause catastrophic structural failure in vulnerable structures. It is therefore imperative that an accurate and reliable methodology is available to predict this phenomenon. The shortcomings of current non-linear implicit solution schemes, found in most commercially-available finite element codes, are discussed. A robust and efficient strategy, which utilises an automated quasi-, static/pseudo-transient hybrid scheme, is presented in this paper and validated using a number of experimental tests. This approach is shown to be able to predict mode-jumping with good accuracy.

Local-field and excitonic effects in the optical response of alpha-alumina

This paper introduces key ingredients of the dielectric response of a-alumina that go beyond an independent-particle (IP) treatment of the valence-electron excitations. The optical-response functions were calculated from first-principles both at the Bethe-Salpeter and the random-phase approximation (RPA) levels. Excitonic effects obtained within the Bethe-Salpeter framework were found essential for reproducing the low-energy part of the experimental spectra (below 15 eV) and the bound exciton in particular. For higher energies, local-field effects introduced through the RPA modified considerably the IP results and provided a satisfactory account of the reflectivity spectra and of the position and shape of the dominant bulk plasmon resonance in the electron energy-loss spectra.

Implementation and testing of Lanczos-based algorithms for Random-Phase Approximation eigenproblems

The treatment of the Random-Phase Approximation Hamiltonians, encountered in different frameworks, like time-dependent density functional theory or Bethe-Salpeter equation, is complicated by their non-Hermicity. Compared to their Hermitian Hamiltonian counterparts, computational methods for the treatment of non-Hermitian Hamiltonians are often less efficient and less stable, sometimes leading to the breakdown of the method. Recently [Gruning et al. Nano Lett. 8 (2009) 28201, we have identified that such Hamiltonians are usually pseudo-Hermitian. Exploiting this property, we have implemented an algorithm of the Lanczos type for Random-Phase Approximation Hamiltonians that benefits from the same stability and computational load as its Hermitian counterpart, and applied it to the study of the optical response of carbon nanotubes. We present here the related theoretical grounds and technical details, and study the performance of the algorithm for the calculation of the optical absorption of a molecule within the Bethe-Salpeter equation framework. (C) 2011 Elsevier B.V. All rights reserved.

Electroencephalographic Activity in Response to Procedural Pain in Preterm Infants Born at 28 and 33 Weeks Gestational Age

OBJECTIVES:: Preterm infants undergo frequent painful procedures in the neonatal intensive care unit. Electroencephalography (EEG) changes in reaction to invasive procedures have been reported in preterm and full-term neonates. Frontal EEG asymmetry as an index of emotion during tactile stimulation shows inconsistent findings in full-term infants, and has not been examined in the context of pain in preterm infants. Our aim was to examine whether heel lance for blood collection induces changes in right-left frontal asymmetry, suggesting negative emotional response, in preterm neonates at different gestational age (GA) at birth and different duration of stay in the neonatal intensive care unit. MATERIALS AND METHODS:: Three groups of preterm infants were compared: set 1: group 1 (n=24), born and tested at 28 weeks GA; group 2 (n=22), born at 28 weeks GA and tested at 33 weeks; set 2: group 3 (n=25), born and tested at 33 weeks GA. EEG power was calculated for 30-second artifact-free periods, in standard frequency bandwidths, in 3 phases (baseline, up to 5 min after heel lance, 10 min after heel lance). RESULTS:: No significant differences were found in right-left frontal asymmetry, or in ipsilateral or contralateral somatosensory response, across phases. In contrast, the Behavioral Indicators of Infant Pain scores changed across phase (P

Healthcare professionals’ response to cachexia in advanced cancer: A qualitative study

Purpose/Objectives: To explore healthcare professionals' experience, understanding, and perception of the needs of patients with cachexia in advanced cancer.

Research Approach: A qualitative approach based on symbolic interactionism.

Setting: A regional cancer center in a large teaching hospital in the United Kingdom.

Participants: 34 healthcare professionals who had experience providing care to patients with cachexia in advanced cancer.

Methodologic Approach: Data collection consisted of two phases: focus group and semistructured interviews. Interviews were digitally recorded and transcribed verbatim for analysis. This article reports on findings from the second phase of data collection.

Findings: Analysis revealed that professional approaches to cachexia were influenced by three overarching and interthinking themes: knowledge, culture, and resources. Healthcare professionals commonly recognized the impact of the syndrome; however, for nonpalliative healthcare professionals, a culture of avoidance and an overreliance on the biomedical model of care had considerable influence on the management of cachexia in patients with advanced cancer.

Conclusions: Cachexia management in patients with advanced cancer can be difficult and is directed by a variable combination of the influence of knowledge, culture of the clinical area, and available resources. Distinct differences exist in the management of cachexia among palliative and nonpalliative care professionals.

Interpretation: This study presented a multiprofessional perspective on the management of cachexia in patients with advanced cancer and revealed that cachexia is a complex and challenging syndrome that needs to be addressed from a holistic model of care.

Knowledge Translation: Cachexia management in patients with advanced cancer is complex and challenging and is directed by a combination of variables. An overreliance on the biomedical model of health and illness occurs in the management of cachexia in patients with advanced cancer. Cachexia needs to be addressed from a holistic model of care to reflect the multidimensional needs of patients and their families.

A randomised double-blind placebo-controlled phase II study of AGI004 for control of chemotherapy-induced diarrhoea

Background: AGI004 is a controlled-release transdermal patch preparation of mecamylamine. We conducted a randomised placebo-controlled phase II study of two dose levels of AGI004 in chemotherapy-induced diarrhoea (CID).

Methods: Adult patients receiving chemotherapy who had experienced diarrhoea (NCI grade 1-2) during previous cycles of chemotherapy were eligible. In all, 64 patients were randomised to receive AGI004 4mg then 8mg per 24 h transdermal patch or placebo for two sequential cycles of chemotherapy. Patients' severity of diarrhoea was physician-assessed using NCI grade of diarrhoea and patient-assessed using information recorded in daily diaries of bowel movements.

Results: Overall AGI004 doubled the odds of a response to treatment on the first day of chemotherapy based on physician assessment of NCI grade of diarrhoea compared with placebo (odds ratio = 2.0, 90% confidence interval: 0.9-4.5) and there was a trend to improved response rates for AGI004 for the full treatment cycle although these results were not statistically significant. There was also evidence of significantly improved response rates based on patient assessment of diarrhoea both overall (P = 0.05) and at the 8-mg dose level (P = 0.02) compared with placebo.

Conclusion: AGI004 demonstrated effectiveness in reducing chemotherapy-associated diarrhoea, with results suggesting response across multiple measurements of diarrhoea. Treatment was well tolerated with no drug-related adverse events. Further evaluation of this agent in the management of CID is warranted.

A phase II study of the potent PARP inhibitor, Rucaparib (PF-01367338, AG014699), with temozolomide in patients with metastatic melanoma demonstrating evidence of chemopotentiation

PURPOSE: poly(ADP ribose) polymerase inhibition has been shown to potentiate the cytotoxicity of DNA damaging agents. A phase I study of rucaparib and temozolomide showed that full-dose temozolomide could be given during PARP inhibition. We report the results of a phase II study of intravenous rucaparib 12 mg/m(2) and oral temozolomide 200 mg/m(2) on days 1-5 every 28 days in patients with advanced metastatic melanoma. METHODS: Patients with chemotherapy naïve measurable metastatic melanoma, performance status =2 and good end-organ function were recruited. Treatment was given until progression. A two stage phase II design was used, with response rate the primary endpoint. Population pharmacokinetics and pharmacodynamics were also explored. RESULTS: Forty-six patients were recruited with 37 patients receiving at least 2 cycles and 17 patients at least 6 cycles. Myelosuppression occurred with 25 patients (54 %) requiring a 25 % dose reduction in temozolomide. The response rate was 17.4 %, median time to progression 3.5 months, median overall survival 9.9 months, and 36 % of patients were progression-free at 6 months. CONCLUSIONS: This study showed that temozolomide (150-200 mg/m(2)/day) can safely be given with a PARP inhibitory dose of rucaparib, increasing progression-free survival over historical controls in metastatic melanoma patients.

A Phase I Trial of Bortezomib in Combination with Epirubicin, Carboplatin and Capecitabine (VECarboX) in Advanced Gastric and Gastro-oesophageal Junction Adenocarcinoma

PURPOSE:
The protease inhibitor bortezomib attenuates the action of NF-κB and has shown preclinical activity alone and in combination with chemotherapy.

DESIGN:
A Phase I dose-escalation study was performed administering bortezomib (0.7, 1.0, 1.3 and 1.6 mg m(-2) on days 1 and 8 from cycle 2 onwards) in combination with Epirubicin 50 mg m(-2) intravenously on day 1, Carboplatin AUC 5 day 1 and Capecitabine 625 mg m(-2) BD days 1-21 every 21 days (VECarboX regimen), in patients with advanced oesophagogastric adenocarcinoma. The primary objective was to define the maximum tolerated dose (MTD) of Bortezomib when combined with ECarboX.

RESULTS:
18 patients received bortezomib 0.7 (n = 6), 1.0 (n = 3), 1.3 (n = 6) and 1.6 mg m(-2) (n = 3) and a protocol amendment reducing the capecitabine dose to 500 mg m(-2) BD was enacted due to myelotoxicity. Common treatment-related non-haematological adverse events of any grade were fatigue (83.3 %), anorexia (55.6 %), constipation (55.6 %) and nausea (55.6 %). Common Grade 3/4 haematological toxicities were neutropenia (77.8 %) and thrombocytopenia (44.4 %). Objective responses were achieved in 6 patients (33.3 %) and a further 5 patients (27.8 %) had stable disease for >8 weeks.

CONCLUSIONS:
The addition of Bortezomib to ECarboX is well tolerated and response rates are comparable with standard chemotherapy.

Phase I and II biotransformation enzymes and polycyclic aromatic hydrocarbons in the Mediterranean mussel (Mytilus galloprovincialis, Lamarck, 1819) collected in front of an oil refinery

The aim of the present study was to investigate the responses of phase I and II biotransformation enzymes and levels of PAHs in the Mediterranean mussel (Mytilus galloprovincialis, Lamarck, 1819) collected from three sites at different distance from an oil refinery. Phase I enzyme activities as NAD(P)H-cyt c red, NADH ferry red, B(a)PMO and phase II as UDPGT. GST were measured in digestive gland while 16 PAHs (US-EPA) in whole soft tissue. An added value to the data obtained in the present study rely on the RDA analysis which showed close correlations between PAHs levels and phase I enzyme activities in mussels collected in front of the refinery. And again a significant spatial correlation between B(a)P levels and NADPH-cyt c red activities was observed using linear models. No differences among sites for B(a) PMO and phase II GST activities were observed, while the application of UDPGT as biomarkers requires further investigation. (C) 2012 Elsevier Ltd. All rights reserved.

1-D constitutive model for evolution of stress-induced R-phase and localized Lüders-like stress-induced martensitic transformation of super-elastic NiTi wires

NiTi alloys have been widely used in the applications for micro-electro-mechanical-systems (MEMS), which often involve some precise and complex motion control. However, when using the NiTi alloys in MEMS application, the main problem to be considered is the degradation of functional property during cycling loading. This also stresses the importance of accurate prediction of the functional behavior of NiTi alloys. In the last two decades, a large number of constitutive models have been proposed to achieve the task. A portion of them focused on the deformation behavior of NiTi alloys under cyclic loading, which is a practical and non-negligible situation. Despite of the scale of modeling studies of the field in NiTi alloys, two experimental observations under uniaxial tension loading have not received proper attentions. First, a deviation from linearity well before the stress-induced martensitic transformation (SIMT) has not been modeled. Recent experiments confirmed that it is caused by the formation of stress-induced R phase. Second, the influence of the well-known localized Lüders-like SIMT on the macroscopic behavior of NiTi alloys, in particular the residual strain during cyclic loading, has not been addressed. In response, we develop a 1-D phenomenological constitutive model for NiTi alloys with two novel features: the formation of stress-induced R phase and the explicit modeling of the localized Lüders-like SIMT. The derived constitutive relations are simple and at the same time sufficient to describe the behavior of NiTi alloys. The accumulation of residual strain caused by R phase under different loading schemes is accurately described by the proposed model. Also, the residual strain caused by irreversible SIMT at different maximum loading strain under cyclic tension loading in individual samples can be explained by and fitted into a single equation in the proposed model. These results show that the proposed model successfully captures the behavior of R phase and the essence of localized SIMT.

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.