Para- and Ortho-Substitutions Are Key Determinants of Polybrominated Diphenyl Ether Activity toward Ryanodine Receptors and Neurotoxicity

BackgroundPolybrominated diphenyl ethers (PBDEs) are widely used flame retardants that bioaccumulate in human tissues. Their neurotoxicity involves dysregulation of calcium ion (Ca(2+))signaling; however, specific mechanisms have yet to be defined.ObjectiveWe aimed to define the structure-activity relationship (SAR) for PBDEs and their metabolites toward ryanodine receptors type 1 (RyR1) and type 2 (RyR2) and to determine whether it predicts neurotoxicity.MethodsWe analyzed [3H]ryanodine binding, microsomal Ca(2+) fluxes, cellular measurements of Ca(2+) homeostasis, and neurotoxicity to define mechanisms and specificity of PBDE-mediated Ca(2+) dysregulation.ResultsPBDEs possessing two ortho-bromine substituents and lacking at least one para-bromine substituent (e.g., BDE-49) activate RyR1 and RyR2 with greater efficacy than corresponding congeners with two para-bromine substitutions (e.g., BDE-47). Addition of a methoxy group in the free para position reduces the activity of parent PBDEs. The hydroxylated BDEs 6-OH-BDE-47 and 4´-OH-BDE-49 are biphasic RyR modulators. Pretreatment of HEK293 cells (derived from human embryonic kidney cells) expressing either RyR1 or RyR2 with BDE-49 (250 nM) sensitized Ca2+ flux triggered by RyR agonists, whereas BDE-47 (250 nM) had negligible activity. The divergent activity of BDE-49, BDE-47, and 6-OH-BDE-47 toward RyRs predicted neurotoxicity in cultures of cortical neurons.ConclusionsWe found that PBDEs are potent modulators of RyR1 and RyR2. A stringent SAR at the ortho and para position determined whether a congener enhanced, inhibited, or exerted nonmonotonic actions toward RyRs. These results identify a convergent molecular target of PBDEs previously identified for noncoplanar polychlorinated biphenyls (PCBs) that predicts their cellular neurotoxicity and therefore could be a useful tool in risk assessment of PBDEs and related compounds

Object Relations in the Museum: A Psychosocial Perspective

This article theorises museum engagement from a psychosocial perspective. With the aid of selected concepts from object relations theory, it explains how the museum visitor can establish a personal relation to museum objects, making use of them as an ‘aesthetic third’ to symbolise experience. Since such objects are at the same time cultural resources, interacting with them helps the individual to feel part of a shared culture. The article elaborates an example drawn from a research project that aimed to make museum collections available to people with physical and mental health problems. It draws on the work of the British psychoanalysts Donald Winnicott and Wilfred Bion to explain the salience of the concepts of object use, potential space, containment and reverie within a museum context. It also refers to the work of the contemporary psychoanalyst Christopher Bollas on how objects can become evocative for individuals both by virtue of their intrinsic qualities and by the way they are used to express personal idiom

HST/STIS Spectroscopy of the Lyman-Alpha Emission Line in the Central Dominant Galaxies in A426, A1795, and A2597: Constraints on Clouds in the Intracluster Medium

We report on HST/STIS spectra of the Lyman-alpha emission in the central dominant galaxies in three rich clusters of galaxies. We find evidence for a population of clouds in the intracluster medium.We detect 10 Ly-alpha absorption systems towards the nucleus of NGC1275 with columns of N(HI) 1E12-1E14 cm-2. The detected absorption features are most consistent with associated nuclear absorption systems. There is very little nuclear absorption at the systemic velocity in NGC1275. This implies that the large columns detected in the 21 cm line towards the parsec scale radio source avoid the line of sight to the nucleus. This gas may be located in a circumnuclear disk or torus. We detect at least one and possibly two absorption features towards the extended Ly-alpha in A426. We do not detect absorption towards the extended Ly-alpha emission in A1795, and A2597 with upper limits N(HI) 1E13 cm-2 for optically thin absorbers. Our data constrain the covering factor of any high column density gas in the ICM to be less than 25%. Our results suggest that the lack of observed intermediate temperature gas is not explained by obscuration. In addition, the low columns of gas on the 100 kpc scales in the ICM suggests that (1) the rate at which cold gas accumulates in the ICM on these scales is very low, and (2) the dense nebulae in the central 10 kpc must have cooled or been deposited in situ.Comment: 6 figure

3C236: Radio Source, Interrupted?

We present new HST STIS/MAMA near-UV images and archival WFPC2 V and R band images which reveal the presence of four star forming regions in an arc along the edge of the dust lane in the giant (4 Mpc) radio galaxy 3C236. Two of the star forming regions are relatively young with ages of order 1E7 yr, while the other two are older with ages of order 1E8 - 1E9 yr which is comparable to the estimated age of the giant radio source. Based on dynamical and spectral aging arguments, we suggest that the fuel supply to the AGN was interrupted for 1E7 yr and has now been restored, resulting in the formation of the inner 2 kpc scale radio source. This time scale is similar to that of the age of the youngest of the star forming regions. We suggest that the transport of gas in the disk is non-steady and that this produces both the multiple episodes of star formation in the disk as well as the multiple epochs of radio source activity. If the inner radio source and the youngest star forming region are related by the same event of gas transport, the gas must be transported from the hundreds of pc scale to the sub-parsec scale on a time scale of 1E7 yr, which is similar to the dynamical time scale of the gas on the hundreds of pc scales

Sphingosine 1-Phosphate Stimulates Smooth Muscle Cell Differentiation and Proliferation by Activating Separate Serum Response Factor Co-factors

Sphingosine 1-phosphate (S1P) is a lipid agonist that regulates smooth muscle cell (SMC) and endothelial cell functions by activating several members of the S1P subfamily of G-protein-coupled Edg receptors. We have shown previously that SMC differentiation is regulated by RhoA-dependent activation of serum response factor (SRF). Because S1P is a strong activator of RhoA, we hypothesized that S1P would stimulate SMC differentiation. Treatment of primary rat aortic SMC cells with S1P activated RhoA as measured by precipitation with a glutathione S-transferase-rhotekin fusion protein. In SMC and 10T1/2 cells, S1P treatment up-regulated the activities of several transiently transfected SMC-specific promoters, and these effects were inhibited by the Rho-kinase inhibitor, Y-27632. S1P also increased smooth muscle alpha-actin protein levels in SMC but had no effect on SRF binding to the smooth muscle alpha-actin CArG B element. Quantitative reverse transcriptase-PCR showed that S1P treatment of SMC or 10T1/2 cells did not increase the mRNA level of either of the recently identified SRF co-factors, myocardin or myocardin-related transcription factor-A (MRTF-A). MRTF-A protein was expressed highly in SMC and 10T1/2 cultures, and importantly the effects of S1P were inhibited by a dominant negative form of MRTF-A indicating that S1P may regulate the transcriptional activity of MRTF-A. Indeed, S1P treatment increased the nuclear localization of FLAG-MRTF-A, and the effect of MRTF-A overexpression on smooth muscle alpha-actin promoter activity was inhibited by dominant negative RhoA. S1P also stimulated SMC growth by activating the early growth response gene, c-fos. This effect was not attenuated by Y-27632 but could be inhibited by the MEK inhibitor, UO126. S1P enhanced SMC growth through ERK-mediated phosphorylation of the SRF co-factor, Elk-1, as measured by gel shift and Elk-1 activation assays. Taken together these results demonstrate that S1P activates multiple signaling pathways in SMC and regulates proliferation by ERK-dependent activation of Elk-1 and differentiation by RhoA-dependent activation of MRTF-A

Blood pressure–associated polymorphism controls ARHGAP42 expression via serum response factor DNA binding

We recently demonstrated that selective expression of the Rho GTPase-activating protein ARHGAP42 in smooth muscle cells (SMCs) controls blood pressure by inhibiting RhoA-dependent contractility, providing a mechanism for the blood pressure–associated locus within the ARHGAP42 gene. The goals of the current study were to identify polymorphisms that affect ARHGAP42 expression and to better assess ARHGAP42’s role in the development of hypertension. Using DNase I hypersensitivity methods and ENCODE data, we have identified a regulatory element encompassing the ARHGAP42 SNP rs604723 that exhibits strong SMC-selective, allele-specific activity. Importantly, CRISPR/Cas9–mediated deletion of this element in cultured human SMCs markedly reduced endogenous ARHGAP42 expression. DNA binding and transcription assays demonstrated that the minor T allele variation at rs604723 increased the activity of this fragment by promoting serum response transcription factor binding to a cryptic cis-element. ARHGAP42 expression was increased by cell stretch and sphingosine 1-phosphate in a RhoA-dependent manner, and deletion of ARHGAP42 enhanced the progression of hypertension in mice treated with DOCA-salt. Our analysis of a well-characterized cohort of untreated borderline hypertensive patients suggested that ARHGAP42 genotype has important implications in regard to hypertension risk. Taken together, our data add insight into the genetic mechanisms that control blood pressure and provide a potential target for individualized antihypertensive therapies

Cetuximab Plus Carboplatin and Paclitaxel With or Without Bevacizumab Versus Carboplatin and Paclitaxel With or Without Bevacizumab in Advanced NSCLC (SWOG S0819): A Randomised, Phase 3 Study

Background EGFR antibodies have shown promise in patients with advanced non-small-cell lung cancer (NSCLC), particularly with squamous cell histology. We hypothesised that EGFR copy number by fluorescence in-situ hybridisation (FISH) can identify patients most likely to benefit from these drugs combined with chemotherapy and we aimed to explore the activity of cetuximab with chemotherapy in patients with advanced NSCLC who are EGFR FISH-positive. Methods We did this open-label, phase 3 study (SWOG S0819) at 277 sites in the USA and Mexico. We randomly assigned (1:1) eligible patients with treatment-naive stage IV NSCLC to receive paclitaxel (200 mg/m 2; every 21 days) plus carboplatin (area under the curve of 6 by modified Calvert formula; every 21 days) or carboplatin plus paclitaxel and bevacizumab (15 mg/kg; every 21 days), either with cetuximab (250 mg/m 2 weekly after loading dose; cetuximab group) or without (control group), stratified by bevacizumab treatment, smoking status, and M-substage using a dynamic-balancing algorithm. Co-primary endpoints were progression-free survival in patients with EGFR FISH-positive cancer and overall survival in the entire study population. We analysed clinical outcomes with the intention-to-treat principle and analysis of safety outcomes included patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov (number NCT00946712). Findings Between Aug 13, 2009, and May 30, 2014, we randomly assigned 1313 patients to the control group (n=657; 277 with bevacizumab and 380 without bevacizumab in the intention-to-treat population) or the cetuximab group (n=656; 283 with bevacizumab and 373 without bevacizumab in the intention-to-treat population). EGFR FISH was assessable in 976 patients and 400 patients (41%) were EGFR FISH-positive. The median follow-up for patients last known to be alive was 35·2 months (IQR 22·9–39·9). After 194 progression-free survival events in the cetuximab group and 198 in the control group in the EGFR FISH-positive subpopulation, progression-free survival did not differ between treatment groups (hazard ratio [HR] 0·92, 95% CI 0·75–1·12; p=0·40; median 5·4 months [95% CI 4·5–5·7] vs 4·8 months [3·9–5·5]). After 570 deaths in the cetuximab group and 593 in the control group, overall survival did not differ between the treatment groups in the entire study population (HR 0·93, 95% CI 0·83–1·04; p=0·22; median 10·9 months [95% CI 9·5–12·0] vs 9·2 months [8·7–10·3]). In the prespecified analysis of EGFR FISH-positive subpopulation with squamous cell histology, overall survival was significantly longer in the cetuximab group than in the control group (HR 0·58, 95% CI 0·36–0·86; p=0·0071), although progression-free survival did not differ between treatment groups in this subgroup (0·68, 0·46–1·01; p=0·055). Overall survival and progression-free survival did not differ among patients who were EGFR FISH non-positive with squamous cell histology (HR 1·04, 95% CI 0·78–1·40; p=0·77; and 1·02, 0·77–1·36; p=0·88 respectively) or patients with non-squamous histology regardless of EGFR FISH status (for EGFR FISH-positive 0·88, 0·68–1·14; p=0·34; and 0·99, 0·78–1·27; p=0·96; respectively; and for EGFR FISH non-positive 1·00, 0·85–1·17; p=0·97; and 1·03, 0·88–1·20; p=0·69; respectively). The most common grade 3–4 adverse events were decreased neutrophil count (210 [37%] in the cetuximab group vs 158 [25%] in the control group), decreased leucocyte count (103 [16%] vs 74 [20%]), fatigue (81 [13%] vs 74 [20%]), and acne or rash (52 [8%] vs one [\u3c 1%]). 59 (9%) patients in the cetuximab group and 31 (5%) patients in the control group had severe adverse events. Deaths related to treatment occurred in 32 (6%) patients in the cetuximab group and 13 (2%) patients in the control group. Interpretation Although this study did not meet its primary endpoints, prespecified subgroup analyses of patients with EGFR FISH-positive squamous-cell carcinoma cancers are encouraging and support continued evaluation of anti-EGFR antibodies in this subpopulation

XPS guide: Charge neutralization and binding energy referencing for insulating samples

This guide deals with methods to control surface charging during XPS analysis of insulating samples and approaches to extracting useful binding energy information. The guide summarizes the causes of surface charging, how to recognize when it occurs, approaches to minimize charge buildup, and methods used to adjust or correct XPS photoelectron binding energies when charge control systems are used. There are multiple ways to control surface charge buildup during XPS measurements, and examples of systems on advanced XPS instruments are described. There is no single, simple, and foolproof way to extract binding energies on insulating material, but advantages and limitations of several approaches are described. Because of the variety of approaches and limitations of each, it is critical for researchers to accurately describe the procedures that have been applied in research reports and publications

Risk factors for late bowel and bladder toxicities in NRG Oncology prostate cancer trials of high-risk patients: A meta-analysis of physician-rated toxicities

Purpose: A meta-analysis of sociodemographic variables and their association with late (\u3e180 days from start of radiation therapy[RT]) bowel, bladder, and clustered bowel and bladder toxicities was conducted in patients with high-risk (clinical stages T2c-T4b or Gleason score 8-10 or prostate-specific antigen level \u3e20) prostate cancer. Methods and materials: Three NRG trials (RTOG 9202, RTOG 9413, and RTOG 9406) that accrued from 1992 to 2000 were used. Late toxicities were measured with the Radiation Therapy Oncology Group Late Radiation Morbidity Scale. After controlling for study, age, Karnofsky Performance Status, and year of accrual, sociodemographic variables were added to the model for each outcome variable of interest in a stepwise fashion using the Fine-Gray regression models with an entry criterion of 0.05. Results: A total of 2432 patients were analyzed of whom most were Caucasian (76%), had a KPS score of 90 to 100 (92%), and received whole-pelvic RT+HT (67%). Of these patients, 13 % and 16% experienced late grade ≥2 bowel and bladder toxicities, respectively, and 2% and 3% experienced late grade ≥3 bowel and bladder toxicities, respectively. Late grade ≥2 clustered bowel and bladder toxicities were seen in approximately 1% of patients and late grade ≥3 clustered toxicities were seen in 2 patients ( Conclusions: Patients with high-risk prostate cancer who receive whole-pelvic RT+LT HT are more likely to have a grade ≥2 bowel toxicity than those who receive prostate-only RT. LT bowel and bladder toxicities were infrequent. Future studies will need to confirm these findings utilizing current radiation technology and patient-reported outcomes