Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at sqrt[s]=510 GeV in p[over →]+p[over →] Collisions

We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510  GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at sqrt[s]=510  GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02<x<0.08, with direct sensitivity to the sign of the gluon contribution.

Translation initiation factor eIF2Bε promotes Wnt-mediated clonogenicity and global translation in intestinal epithelial cells

Modulation of global mRNA translation, which is essential for intestinal stem cell function, is controlled by Wnt signaling. Loss of tumor supressor APC in stem cells drives adenoma formation through hyperactivion of Wnt signaling and dysregulated translational control. It is unclear whether factors that coordinate global translation in the intestinal epithelium are needed for APC-driven malignant transformation. Here we identified nucleotide exchange factor eIF2Bε as a translation initiation factor involved in Wnt-mediated intestinal epithelial stemness. Using eIF2Bε^Arg191His mice with a homozygous point mutation that leads to dysfunction in the enzymatic activity, we demonstrate that eIF2Bε is involved in small intestinal crypt formation, stemness marker expression, and secreted Paneth cell-derived granule formation. Wnt hyperactivation in ex vivo eIF2Bε^Arg191His organoids, using a GSK3β inhibitor to mimic Apc driven transformation, shows that eIF2Bε is essential for Wnt-mediated clonogenicity and associated increase of the global translational capacity. Finally, we observe high eIF2Bε expression in human colonic adenoma tissues, exposing eIF2Bε as a potential target of CRC stem cells with aberrant Wnt signaling.

Erratum: Evolution of π^{0} Suppression in Au+Au Collisions from sqrt[s_{NN}]=39 to 200 GeV [Phys. Rev. Lett. 109, 152301 (2012)]

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

Specific Programmed Multiple Development–Thin Layer Chromatography of Furazolidone in Chicken, Turkey, Swine, and Bovine Tissues: Collaborative Study

A specific method for assay of furazolidone at 2 ppb has been developed using programmed multiple development-thin layer chromatography (PMD-TLC) and the conversion of the drug to a fluorescent species which is quantitated by fluorodensitometry on the TLC plate. The method requires only 5 g tissue, specifies an automatic spotter for PMD-TLC, and is capable of measuring &lt;1 ng of drug when the fluorodensitometer is coupled with a computing integrator. This procedure requires an average of 2 man-hours per sample and can be completed in one day. Six laboratories collaboratively studied the method for assay of furazolidone at the 2, 3, and 6 ppb levels in chicken, turkey, swine, and bovine tissues. Tissues were fortified by each laboratory and then processed through extraction, solvent partition, programmed multiple development-thin layer chromatography, and fluorodensitometry. Results showed satisfactory recoveries and accuracy. A statistical comparison of the results demonstrated that 5 of the 6 laboratories obtained similar results. The higher responses from the sixth laboratory appeared to be due to an exceptional vacuum system and the use of silated flasks. The mean drug recovery response for the tissues spiked at 2 ppb from the 5 laboratories was 2.2324 ng ± 20.2% (SD), which at the 99.7% confidence level gives no overlap with control tissue data. The results can be expected to be repeatable within and among laboratories.

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions

The PHENIX collaboration presents first measurements of low-momentum (0.4<p_{T}<3  GeV/c) direct-photon yields from Au+Au collisions at sqrt[s_{NN}]=39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields observed in Au+Au collisions at sqrt[s_{NN}]=200. Analyzing the photon yield as a function of the experimental observable dN_{ch}/dη reveals that the low-momentum (>1  GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (>5  GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

A specific gene expression signature for visceral organ metastasis in breast cancer

BACKGROUND

Visceral organ metastasis is associated with poor survival outcomes in terms of metastasis free- and overall survival in breast carcinomas. Identification of a gene expression profile in tumours that selects a subpopulation of patients that is more likely to develop visceral organ metastases will help elucidate mechanisms for the development of distant metastases and could be of clinical value. With this study we aimed to determine genomic predictors that would help to distinguish breast cancer patients with more likelihood to develop visceral metastasis.

METHODS

Gene expression profiling data of 157 primary tumours from breast cancer patients who developed distant metastases were analyzed and differentially expressed genes between the group of tumours with visceral metastasis and the those without visceral metastases were identified. Published data were used to validate our findings. Multivariate logistic regression tests were applied to further investigate the association between the gene-expression-signature and clinical variables. Survival analyses were performed by the Kaplan-Meier method.

RESULTS

Fourteen differentially expressed genes (WDR6, CDYL, ATP6V0A4, CHAD, IDUA, MYL5, PREP, RTN4IP1, BTG2, TPRG1, ABHD14A, KIF18A, S100PBP and BEND3) were identified between the group of tumours with and without visceral metastatic disease. Five of these genes (CDYL, ATP6V0A4, PREP, RTN4IP1 and KIF18A) were up-regulated and the other genes were down-regulated. This gene expression signature was validated in the training and in the independent data set (p 2.13e- 08 and p 9.68e- 06, respectively). Multivariate analyses revealed that the 14-gene-expression-signature was associated with visceral metastatic disease (p 0.001, 95% CI 1.43-4.27), independent of other clinicopathologic features. This signature has been also found to be associated with survival status of the patients (p < .001).

CONCLUSION

We have identified an unique gene expression signature which is specific to visceral metastasis. This 14-gene-expression-signature may play a role in identifying the subgroup of patients with potential to develop visceral metastasis.

Epithelial-to-mesenchymal transition status of primary breast carcinomas and its correlation with metastatic behavior

Background

Epithelial-to-mesenchymal transition (EMT) has been implicated as an important step in the development of distant metastases. We therefore wished to study EMT status of primary breast carcinomas from patients who during follow-up developed distant metastases.

Methods

mRNA expression profiles of primary breast carcinoma samples (n = 151) from patients who developed metastatic disease were analyzed and EMT status was designated using a previously described EMT-core signature. EMT status of the primary tumor was correlated to clinicopathological characteristics, molecular subtypes, metastasis pattern, chemotherapy response and survival outcomes. In addition, using immunohistochemistry, the expression levels of several proteins implicated in EMT were studied (CDH1, CDH2, NAT1, SNAI2, TWIST1, VIM, and ZEB1) compared with the designated EMT status and survival.

Results

Utilizing the 130-gene-EMT-core signature, 66.2% of the primary tumors in the current study was assessed as EMT-activated. In contrast to our expectations, analyses revealed that 84.6% of Luminal A tumors, 65.1% of Luminal B tumors, and 55.6% of HER2-like had an activated EMT status, compared to only 25% of the basal-type tumors (p < 0.001). EMT status was not correlated to the pattern of metastatic disease, metastasis-specific survival, and overall survival. Similarly, there was not a significant association between EMT status of the primary tumor and chemotherapy response in the metastatic setting. Immunostaining for NAT1 and TWIST1 correlated with the EMT status (p 0.003 and p 0.047, respectively). Multivariate analyses showed that NAT1 and TWIST1 staining was significantly associated with EMT status regardless of the estrogen receptor status of the tumors (p values: 0.020 and 0.027, respectively).

Conclusions

The EMT status of breast cancers, as defined by the presence of a core EMT gene expression signature is associated with non-basal-type tumors, but not with the pattern of distant metastasis. Of several potential immunohistochemical EMT markers, only NAT1 and TWIST1 expression levels were associated with the gene expression-based EMT status.

Electronic supplementary material

The online version of this article (10.1007/s10549-018-05089-5) contains supplementary material, which is available to authorized users.

A NEW ECOLOGY IN HEALTH CARE

Providers and practices need to start making changes now to prepare for a new way of doing business and caring for patients; and physician leaders need to lead the charge.

Novel PEX3 Gene Mutations Resulting in a Moderate Zellweger Spectrum Disorder

BACKGROUND

Peroxisome biogenesis disorders (PBDs) may have a variable clinical expression, ranging from severe, lethal to mild phenotypes with progressive evolution. PBDs are autosomal recessive disorders caused by mutations in PEX genes, which encode proteins called peroxins, involved in the assembly of the peroxisome. Patient Description: We herein report a patient who is currently 9 years old and who is compound heterozygous for two novel mutations in the PEX3 gene.

RESULTS

Mild biochemical abnormalities of the peroxisomal parameters suggested a Zellweger spectrum defect in the patient. Sequence analysis of the PEX3 gene identified two novel heterozygous, pathogenic mutations.

CONCLUSION

Mutations in PEX3 usually result in a severe, early lethal phenotype. We report a patient compound heterozygous for two novel mutations in the PEX3 gene, who is less affected than previously reported patients with a defect in the PEX3 gene. Our findings indicate that PEX3 defects may cause a disease spectrum similar as previously observed for other PEX gene defects.

Centrality-Dependent Modification of Jet-Production Rates in Deuteron-Gold Collisions at √[s(NN)]=200 GeV

Jet production rates are measured in p+p and d+Au collisions at sqrt[s_{NN}]=200  GeV recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the R=0.3 anti-k_{t} algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multiwire proportional chambers, and the jet transverse momentum (p_{T}) spectra are corrected for the detector response. Spectra are reported for jets with 12<p_{T}<50  GeV/c, within a pseudorapidity acceptance of |η|<0.3. The nuclear-modification factor (R_{dAu}) values for 0%-100% d+Au events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected R_{dAu} values and central-to-peripheral ratios (R_{CP}) show large, p_{T}-dependent deviations from unity, challenging the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.

Collagen-rich stroma in aggressive colon tumors induces mesenchymal gene expression and tumor cell invasion

Gene expression-based classification systems have identified an aggressive colon cancer subtype with mesenchymal features, possibly reflecting epithelial-to-mesenchymal transition (EMT) of tumor cells. However, stromal fibroblasts contribute extensively to the mesenchymal phenotype of aggressive colon tumors, challenging the notion of tumor EMT. To separately study the neoplastic and stromal compartments of colon tumors, we have generated a stroma gene filter (SGF). Comparative analysis of stroma^high and stroma^low tumors shows that the neoplastic cells in stroma^high tumors express specific EMT drivers (ZEB2, TWIST1, TWIST2) and that 98% of differentially expressed genes are strongly correlated with them. Analysis of differential gene expression between mesenchymal and epithelial cancer cell lines revealed that hepatocyte nuclear factor 4α (HNF4α), a transcriptional activator of intestinal (epithelial) differentiation, and its target genes are highly expressed in epithelial cancer cell lines. However, mesenchymal-type cancer cell lines expressed only part of the mesenchymal genes expressed by tumor-derived neoplastic cells, suggesting that external cues were lacking. We found that collagen-I dominates the extracellular matrix in aggressive colon cancer. Mimicking the tumor microenvironment by replacing laminin-rich Matrigel with collagen-I was sufficient to induce tumor-specific mesenchymal gene expression, suppression of HNF4α and its target genes, and collective tumor cell invasion of patient-derived colon tumor organoids. The data connect collagen-rich stroma to mesenchymal gene expression in neoplastic cells and to collective tumor cell invasion. Targeting the tumor-collagen interface may therefore be explored as a novel strategy in the treatment of aggressive colon cancer.

Health Care Transformation: A Strategy Rooted in Data and Analytics

Today's consumers purchasing any product or service are armed with information and have high expectations. They expect service providers and payers to know about their unique needs. Data-driven decisions can help organizations meet those expectations and fulfill those needs.Health care, however, is not strictly a retail relationship-the sacred trust between patient and doctor, the clinician-patient relationship, must be preserved. The opportunities and challenges created by the digitization of health care are at the crux of the most crucial strategic decisions for academic medicine. A transformational vision grounded in data and analytics must guide health care decisions and actions.In this Commentary, the authors describe three examples of the transformational force of data and analytics to improve health care in order to focus attention on academic medicine's vital role in guiding the needed changes.

Asking Incisive Questions

Boards must help management chal- lenge their deeply held beliefs about health care by asking incisive questions.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

Measurement of Long-Range Angular Correlation and Quadrupole Anisotropy of Pions and (Anti)Protons in Central d+Au Collisions at sqrt[s_{NN}]=200 GeV

We present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers in central d+Au and minimum bias p+p collisions at sqrt[s_{NN}]=200 GeV. The charged hadron is measured at midrapidity |η|<0.35, and the energy is measured at large rapidity (-3.7<η<-3.1, Au-going direction). An enhanced near-side angular correlation across |Δη|>2.75 is observed in d+Au collisions. Using the event plane method applied to the Au-going energy distribution, we extract the anisotropy strength v_{2} for inclusive charged hadrons at midrapidity up to p_{T}=4.5 GeV/c. We also present the measurement of v_{2} for identified π^{±} and (anti)protons in central d+Au collisions, and observe a mass-ordering pattern similar to that seen in heavy-ion collisions. These results are compared with viscous hydrodynamic calculations and measurements from p+Pb at sqrt[s_{NN}]=5.02 TeV. The magnitude of the mass ordering in d+Au is found to be smaller than that in p+Pb collisions, which may indicate smaller radial flow in lower energy d+Au collisions.

Cold-nuclear-matter effects on heavy-quark production at forward and backward rapidity in d + Au collisions at √sNN = 200 GeV

The PHENIX experiment has measured open heavy-flavor production via semileptonic decay over the transverse momentum range 1 < p(T) < 6  GeV/c at forward and backward rapidity (1.4 < |y| < 2.0) in d+Au and p + p collisions at √sNN = 200  GeV. In central d+Au collisions, relative to the yield in p + p collisions scaled by the number of binary nucleon-nucleon collisions, a suppression is observed at forward rapidity (in the d-going direction) and an enhancement at backward rapidity (in the Au-going direction). Predictions using nuclear-modified-parton-distribution functions, even with additional nuclear-p(T) broadening, cannot simultaneously reproduce the data at both rapidity ranges, which implies that these models are incomplete and suggests the possible importance of final-state interactions in the asymmetric d + Au collision system. These results can be used to probe cold-nuclear-matter effects, which may significantly affect heavy-quark production, in addition to helping constrain the magnitude of charmonia-breakup effects in nuclear matter.

Azimuthal-angle dependence of charged-pion-interferometry measurements with respect to second- and third-order event planes in Au+Au collisions at √[S(NN)]=200 GeV

Charged-pion-interferometry measurements were made with respect to the second- and third-order event plane for Au+Au collisions at sqrt[s_{NN}]=200  GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the second- and third-order event planes. The results for the second-order dependence indicate that the initial eccentricity is reduced during the medium evolution, which is consistent with previous results. In contrast, the results for the third-order dependence indicate that the initial triangular shape is significantly reduced and potentially reversed by the end of the medium evolution, and that the third-order oscillations are largely dominated by the dynamical effects from triangular flow.

Quadrupole anisotropy in dihadron azimuthal correlations in central d+Au collisions at √(s(NN))=200 GeV

The PHENIX collaboration at the Relativistic Heavy Ion Collider (RHIC) reports measurements of azimuthal dihadron correlations near midrapidity in d+Au collisions at √(s(NN))=200 GeV. These measurements complement recent analyses by experiments at the Large Hadron Collider (LHC) involving central p+Pb collisions at √(s(NN))=5.02 TeV, which have indicated strong anisotropic long-range correlations in angular distributions of hadron pairs. The origin of these anisotropies is currently unknown. Various competing explanations include parton saturation and hydrodynamic flow. We observe qualitatively similar, but larger, anisotropies in d+Au collisions at RHIC compared to those seen in p+Pb collisions at the LHC. The larger extracted v2 values in d+Au are consistent with expectations from hydrodynamic calculations owing to the larger expected initial-state eccentricity compared with that from p+Pb collisions. When both are divided by an estimate of the initial-state eccentricity the scaled anisotropies follow a common trend with multiplicity that may extend to heavy ion data at RHIC and the LHC, where the anisotropies are widely thought to arise from hydrodynamic flow.

Nuclear modification of ψ', χc, and J/ψ production in d+Au collisions at sqrt[s(NN)]=200 GeV

We present results for three charmonia states (ψ', χc, and J/ψ) in d+Au collisions at |y|<0.35 and sqrt[s(NN)]=200  GeV. We find that the modification of the ψ' yield relative to that of the J/ψ scales approximately with charged particle multiplicity at midrapidity across p+A, d+Au, and A+A results from the Super Proton Synchrotron and the Relativistic Heavy Ion Collider. In large-impact-parameter collisions we observe a similar suppression for the ψ' and J/ψ, while in small-impact-parameter collisions the more weakly bound ψ' is more strongly suppressed. Owing to the short time spent traversing the Au nucleus, the larger ψ' suppression in central events is not explained by an increase of the nuclear absorption owing to meson formation time effects.

Medium modification of jet fragmentation in Au+Au collisions at √[s(NN)]=200 GeV measured in direct photon-hadron correlations

The jet fragmentation function is measured with direct photon-hadron correlations in p+p and Au+Au collisions at √[s(NN)]=200 GeV. The p(T) of the photon is an excellent approximation to the initial p(T) of the jet and the ratio z(T)=p(T)(h)/p(T)(γ) is used as a proxy for the jet fragmentation function. A statistical subtraction is used to extract the direct photon-hadron yields in Au+Au collisions while a photon isolation cut is applied in p+p. I(AA), the ratio of hadron yield opposite the photon in Au+Au to that in p+p, indicates modification of the jet fragmentation function. Suppression, most likely due to energy loss in the medium, is seen at high z(T). The associated hadron yield at low z(T) is enhanced at large angles. Such a trend is expected from redistribution of the lost energy into increased production of low-momentum particles.

Modulation of neuroblastoma disease pathogenesis by an extensive network of epigenetically regulated microRNAs

MicroRNAs (miRNAs) contribute to the pathogenesis of many forms of cancer, including the pediatric cancer neuroblastoma, but the underlying mechanisms leading to altered miRNA expression are often unknown. Here, a novel integrated approach for analyzing DNA methylation coupled with miRNA and mRNA expression data sets identified 67 epigenetically regulated miRNA in neuroblastoma. A large proportion (42%) of these miRNAs was associated with poor patient survival when underexpressed in tumors. Moreover, we demonstrate that this panel of epigenetically silenced miRNAs targets a large set of genes that are overexpressed in tumors from patients with poor survival in a highly redundant manner. The genes targeted by the epigenetically regulated miRNAs are enriched for a number of biological processes, including regulation of cell differentiation. Functional studies involving ectopic overexpression of several of the epigenetically silenced miRNAs had a negative impact on neuroblastoma cell viability, providing further support to the concept that inactivation of these miRNAs is important for neuroblastoma disease pathogenesis. One locus, miR-340, induced either differentiation or apoptosis in a cell context dependent manner, indicating a tumor suppressive function for this miRNA. Intriguingly, it was determined that miR-340 is upregulated by demethylation of an upstream genomic region that occurs during the process of neuroblastoma cell differentiation induced by all-trans retinoic acid (ATRA). Further biological studies of miR-340 revealed that it directly represses the SOX2 transcription factor by targeting of its 3'-untranslated region, explaining the mechanism by which SOX2 is downregulated by ATRA. Although SOX2 contributes to the maintenance of stem cells in an undifferentiated state, we demonstrate that miR-340-mediated downregulation of SOX2 is not required for ATRA induced differentiation to occur. In summary, our results exemplify the dynamic nature of the miRNA epigenome and identify a remarkable network of miRNA/mRNA interactions that significantly contribute to neuroblastoma disease pathogenesis.

Cold-nuclear-matter effects on heavy-quark production in d+Au collisions at sqrt[S(NN)]=200 GeV

The PHENIX experiment has measured electrons and positrons at midrapidity from the decays of hadrons containing charm and bottom quarks produced in d+Au and p+p collisions at sqrt[S(NN)]=200 GeV in the transverse-momentum range 0.85 ≤ p(T)(e) ≤ 8.5 GeV/c. In central d+Au collisions, the nuclear modification factor R(dA) at 1.5<p(T)<5 GeV/c displays evidence of enhancement of these electrons, relative to those produced in p+p collisions, and shows that the mass-dependent Cronin enhancement observed at the Relativistic Heavy Ion Collider extends to the heavy D meson family. A comparison with the neutral-pion data suggests that the difference in cold-nuclear-matter effects on light- and heavy-flavor mesons could contribute to the observed differences between the π(0) and heavy-flavor-electron nuclear modification factors R(AA).

Exon-level expression analyses identify MYCN and NTRK1 as major determinants of alternative exon usage and robustly predict primary neuroblastoma outcome

Background:

Using mRNA expression-derived signatures as predictors of individual patient outcome has been a goal ever since the introduction of microarrays. Here, we addressed whether analyses of tumour mRNA at the exon level can improve on the predictive power and classification accuracy of gene-based expression profiles using neuroblastoma as a model.

Methods:

In a patient cohort comprising 113 primary neuroblastoma specimens expression profiling using exon-level analyses was performed to define predictive signatures using various machine-learning techniques. Alternative transcript use was calculated from relative exon expression. Validation of alternative transcripts was achieved using qPCR- and cell-based approaches.

Results:

Both predictors derived from the gene or the exon levels resulted in prediction accuracies >80% for both event-free and overall survival and proved as independent prognostic markers in multivariate analyses. Alternative transcript use was most prominently linked to the amplification status of the MYCN oncogene, expression of the TrkA/NTRK1 neurotrophin receptor and survival.

Conclusion:

As exon level-based prediction yields comparable, but not significantly better, prediction accuracy than gene expression-based predictors, gene-based assays seem to be sufficiently precise for predicting outcome of neuroblastoma patients. However, exon-level analyses provide added knowledge by identifying alternative transcript use, which should deepen the understanding of neuroblastoma biology.

Evolution of π(0) suppression in Au+Au collisions from √(s(NN))=39 to 200 GeV

Neutral-pion π(0) spectra were measured at midrapidity (|y|<0.35) in Au+Au collisions at √(s(NN))=39 and 62.4 GeV and compared with earlier measurements at 200 GeV in a transverse-momentum range of 1<p(T)<10 GeV/c. The high-p(T) tail is well described by a power law in all cases, and the powers decrease significantly with decreasing center-of-mass energy. The change of powers is very similar to that observed in the corresponding spectra for p+p collisions. The nuclear modification factors (R(AA)) show significant suppression, with a distinct energy, centrality, and p(T) dependence. Above p(T)=7 GeV/c, R(AA) is similar for √(s(NN))=62.4 and 200 GeV at all centralities. Perturbative-quantum-chromodynamics calculations that describe R(AA) well at 200 GeV fail to describe the 39 GeV data, raising the possibility that, for the same p(T) region, the relative importance of initial-state effects and soft processes increases at lower energies. The p(T) range where π(0) spectra in central Au+Au collisions have the same power as in p+p collisions is ≈5 and 7 GeV/c for √(s(NN))=200 and 62.4 GeV, respectively. For the √(s(NN))=39 GeV data, it is not clear whether such a region is reached, and the x(T) dependence of the x(T)-scaling power-law exponent is very different from that observed in the √(s(NN))=62 and 200 GeV data, providing further evidence that initial-state effects and soft processes mask the in-medium suppression of hard-scattered partons to higher p(T) as the collision energy decreases.

Observation of direct-photon collective flow in Au + Au collisions at √s(NN)] = 200 GeV

The second Fourier component v(2) of the azimuthal anisotropy with respect to the reaction plane is measured for direct photons at midrapidity and transverse momentum (p(T)) of 1-12 GeV/c in Au + Au collisions at √s(NN)] = 200 GeV. Previous measurements of this quantity for hadrons with p(T) < 6 GeV/c indicate that the medium behaves like a nearly perfect fluid, while for p(T) > 6 GeV/c a reduced anisotropy is interpreted in terms of a path-length dependence for parton energy loss. In this measurement with the PHENIX detector at the Relativistic Heavy Ion Collider we find that for p(T) > 4 GeV/c the anisotropy for direct photons is consistent with zero, which is as expected if the dominant source of direct photons is initial hard scattering. However, in the p(T) < 4 GeV/c region dominated by thermal photons, we find a substantial direct-photon v(2) comparable to that of hadrons, whereas model calculations for thermal photons in this kinematic region underpredict the observed v(2).

Measurements of higher order flow harmonics in Au+Au collisions at √s(NN)=200 GeV

Flow coefficients ν(n) for n=2, 3, 4, characterizing the anisotropic collective flow in Au+Au collisions at √s(NN)=200 GeV, are measured relative to event planes Ψ(n), determined at large rapidity. We report ν(n) as a function of transverse momentum and collision centrality, and study the correlations among the event planes of different order n. The ν(n) are well described by hydrodynamic models which employ a Glauber Monte Carlo initial state geometry with fluctuations, providing additional constraining power on the interplay between initial conditions and the effects of viscosity as the system evolves. This new constraint can serve to improve the precision of the extracted shear viscosity to entropy density ratio η/s.

Suppression of back-to-back hadron pairs at forward rapidity in d+Au collisions at √s(NN)=200 GeV

Back-to-back hadron pair yields in d+Au and p+p collisions at √s(NN)=200 GeV were measured with the PHENIX detector at the Relativistic Heavy Ion Collider. Rapidity separated hadron pairs were detected with the trigger hadron at pseudorapidity |η|<0.35 and the associated hadron at forward rapidity (deuteron direction, 3.0<η<3.8). Pairs were also detected with both hadrons measured at forward rapidity; in this case, the yield of back-to-back hadron pairs in d+Au collisions with small impact parameters is observed to be suppressed by a factor of 10 relative to p+p collisions. The kinematics of these pairs is expected to probe partons in the Au nucleus with a low fraction x of the nucleon momenta, where the gluon densities rise sharply. The observed suppression as a function of nuclear thickness, p(T), and η points to cold nuclear matter effects arising at high parton densities.

Cold nuclear matter effects on J/ψ yields as a function of rapidity and nuclear geometry in d+A collisions at sqrt[s(NN)]=200 GeV

We present measurements of J/ψ yields in d+Au collisions at sqrt[s(NN)]=200  GeV recorded by the PHENIX experiment and compare them with yields in p+p collisions at the same energy per nucleon-nucleon collision. The measurements cover a large kinematic range in J/ψ rapidity (-2.2<y<2.4) with high statistical precision and are compared with two theoretical models: one with nuclear shadowing combined with final state breakup and one with coherent gluon saturation effects. In order to remove model dependent systematic uncertainties we also compare the data to a simple geometric model. The forward rapidity data are inconsistent with nuclear modifications that are linear or exponential in the density weighted longitudinal thickness, such as those from the final state breakup of the bound state.

Cross section and parity-violating spin asymmetries of W± boson production in polarized p + p collisions at sqrt[s] = 500 GeV

Large parity-violating longitudinal single-spin asymmetries A(L)(e+) = -0.86(-0.14) (+0.30) and A(L)(e-) = 0.88(-0.71) (+0.12) are observed for inclusive high transverse momentum electrons and positrons in polarized p+p collisions at a center-of-mass energy of sqrt[s] = 500 GeV with the PHENIX detector at RHIC. These e± come mainly from the decay of W± and Z0 bosons, and their asymmetries directly demonstrate parity violation in the couplings of the W± to the light quarks. The observed electron and positron yields were used to estimate W± boson production cross sections for the e± channels of σ(pp → W+ X) × BR(W+ → e+ ν(e)) = 144.1 ± 21.2(stat)(-10.3) (+3.4) (syst) ± 21.6(norm)  pb, and σ(pp → W- X) × BR(W- → e- ν[over ¯](e)) = 31.7 ± 12.1(stat)(-8.2) (+10.1) (syst) ± 4.8(norm)  pb.

Azimuthal anisotropy of π⁰ production in Au+Au collisions at sqrt((s)NN)=200 GeV: path-length dependence of jet quenching and the role of initial geometry

We have measured the azimuthal anisotropy of π⁰ production for 1<p(T)<18  GeV/c for Au+Au collisions at sqrt((s)NN)=200  GeV. The observed anisotropy shows a gradual decrease for 3≲p(T)≲7-10  GeV/c, but remains positive beyond 10  GeV/c. The magnitude of this anisotropy is underpredicted, up to at least ∼10  GeV/c, by current perturbative QCD (PQCD) energy-loss model calculations. An estimate of the increase in anisotropy expected from initial-geometry modification due to gluon saturation effects and fluctuations is insufficient to account for this discrepancy. Calculations that implement a path-length dependence steeper than what is implied by current PQCD energy-loss models show reasonable agreement with the data.

Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sq.rt(s(NN))=200 GeV

Differential measurements of the elliptic (v(2)) and hexadecapole (v(4)) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum (p(T)) and collision centrality or number of participant nucleons (N(part)) for Au+Au collisions at sq.rt(s(NN))=200  GeV. The v(2,4) measurements at pseudorapidity |η|≤0.35, obtained with four separate reaction-plane detectors positioned in the range 1.0<|η|<3.9, show good agreement, indicating the absence of significant Δη-dependent nonflow correlations. Sizable values for v(4)(p(T)) are observed with a ratio v(4)(p(T),N(part))/v(2)(2)(p(T),N(part))≈0.8 for 50≲N(part)≲200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For N(part)≳200 this ratio increases up to 1.7 in the most central collisions.

Transition in yield and azimuthal shape modification in dihadron correlations in relativistic heavy ion collisions

Hard-scattered parton probes produced in collisions of large nuclei indicate large partonic energy loss, possibly with collective produced-medium response to the lost energy. We present measurements of π^{0} trigger particles at transverse momenta p{T}{t}=4-12  GeV/c and associated charged hadrons (p{T}{a}=0.5-7  GeV/c) vs relative azimuthal angle Δϕ in Au+Au and p+p collisions at sqrt[s{NN}]=200  GeV. The Au+Au distribution at low p{T}{a}, whose shape has been interpreted as a medium effect, is modified for p{T}{t}<7  GeV/c. At higher p{T}{t}, the data are consistent with unmodified or very weakly modified shapes, even for the lowest measured p{T}{a}, which quantitatively challenges some medium response models. The associated yield of hadrons opposing the trigger particle in Au+Au relative to p+p (I{AA}) is suppressed at high p{T} (I{AA}≈0.35-0.5), but less than for inclusive suppression (R{AA}≈0.2).

Measurement of bottom versus charm as a function of transverse momentum with electron-hadron correlations in p + p collisions at square root of s = 200 GeV

The momentum distribution of electrons from semileptonic decays of charm and bottom quarks for midrapidity |y|<0.35 in p+p collisions at square root of s=200 GeV is measured by the PHENIX experiment at the Relativistic Heavy Ion Collider over the transverse momentum range 2<pT<7 GeV/c. The ratio of the yield of electrons from bottom to that from charm is presented. The ratio is determined using partial D/D-->e(+/-)K(-/+)X (K unidentified) reconstruction. It is found that the yield of electrons from bottom becomes significant above 4 GeV/c in pT. A fixed-order-plus-next-to-leading-log perturbative quantum chromodynamics calculation agrees with the data within the theoretical and experimental uncertainties. The extracted total bottom production cross section at this energy is sigma(bb)=3.2(-1.1)(+1.2)(stat)(-1.3)(+1.4)(syst)mub.

Gluon-spin contribution to the proton spin from the double-helicity asymmetry in inclusive pi0 production in polarized p+p collisions at [sqrt]s=200 GeV

The double helicity asymmetry in neutral pion production for pT=1 to 12 GeV/c was measured with the PHENIX experiment to access the gluon-spin contribution, DeltaG, to the proton spin. Measured asymmetries are consistent with zero, and at a theory scale of micro2=4 GeV2 a next to leading order QCD analysis gives DeltaG[0.02,0.3]=0.2, with a constraint of -0.7<DeltaG[0.02,0.3]<0.5 at Deltachi2=9 (approximately 3sigma) for the sampled gluon momentum fraction (x) range, 0.02 to 0.3. The results are obtained using predictions for the measured asymmetries generated from four representative fits to polarized deep inelastic scattering data. We also consider the dependence of the DeltaG constraint on the choice of the theoretical scale, a dominant uncertainty in these predictions.

Galectin-1 is a major effector of TrkB-mediated neuroblastoma aggressiveness

Expression of Trk receptors is an important prognostic factor in neuroblastoma (NB) and other cancers. TrkB and its ligand brain-derived neurotrophic factor (BDNF) are preferentially expressed in NB with poor prognosis, conferring invasive and metastatic potential to the tumor cells as well as enhancing therapy resistance. Galectin-1 (Gal-1) has emerged as an interesting cancer target, as it is involved in modulating cell proliferation, cell death and cell migration, all of which are linked to cancer initiation and progression. We previously identified Gal-1 mRNA to be upregulated in patients with aggressive, relapsing NB and found that Gal-1 protein was upregulated in human SY5Y NB cells on activation of ectopically expressed TrkB (SY5Y-TrkB), but not TrkA (SY5Y-TrkA). Here, we report that Gal-1 mRNA levels positively correlated with TrkB expression and anticorrelated with TrkA expression in a cohort of 102 primary NB. Immunohistochemical analyses of 92 primary NB specimens revealed high Gal-1 expression in stromal septae and in neuroblasts. BDNF-mediated activation of TrkB enhanced invasiveness and migration in vitro, which could be impaired by transient transfection using Gal-1-specific siRNA or a neutralizing antibody directed against Gal-1. The addition of recombinant Gal-1 (rGal-1) in the absence of BDNF partially restored migration and invasive capacity. Using the Trk inhibitor K252a, we could show that the upregulation of Gal-1 protein strictly depended on activated TrkB. Our data suggest that targeting Gal-1 might be a promising strategy for the treatment of aggressive NB.

Antiplectin autoantibodies in subepidermal blistering diseases

BACKGROUND

Hemidesmosomal proteins may become targets of autoimmunity in subepidermal blistering diseases. Well-known recognized autoantigens are the intracellular plaque protein BP230, the transmembrane BP180 and its shed ectodomain LAD-1.

OBJECTIVES

To establish the prevalence of autoimmunity against plectin, another intracellular plaque protein, and to investigate its antigenic sites.

METHODS

Two hundred and eighty-two patients with subepidermal blistering diseases, investigated by routine immunoblot analysis for possible antiplectin antibodies, were included in the study. Epitope mapping was performed using recombinantly produced overlapping plectin domains from the actin-binding domain to the rod domain. The COOH-terminal region of plectin was not included in the study.

RESULTS

In 11 of 282 (3.9%) patients an immunoblot staining pattern identical to that of antiplectin monoclonal antibody HD121 was found. Affinity-purified antibodies bound back to normal human skin in a pattern typical for plectin, i.e. to the epidermal basement membrane zone as well as to keratinocytes in the epidermis, and to myocytes. No binding was seen to plectin-deficient skin of a patient with epidermolysis bullosa simplex with muscular dystrophy. Epitope mapping of the plectin molecule showed that the central coiled-coil rod domain is an immunodominant hotspot as 92% of the sera with antiplectin antibodies reacted with it. Most patients with antiplectin antibodies also had antibodies to other pemphigoid antigens.

CONCLUSIONS

Plectin is a minor pemphigoid antigen with an immunodominant epitope located on the central rod domain.

Hemodynamic stability ensured by a low dose, low volume, unilateral hypobaric spinal block: modification of a technique

We report the case of an 89-year-old female with a history of arterial hypertension, intermittent rapid atrial fibrillation and severe aortic valve stenosis, suffering from femoral neck fracture. Hyperbaric unilateral spinal anesthesia is a known technique to obtain stable hemodynamics combined with the possibility of continuous neurologic evaluation and preservation of cognitive functions. Because a hyperbaric unilateral technique can be very painful in case of traumatic hip fracture, a low dose, low volume, unilateral hypobaric spinal block may be an adequate alternative. In the present case report, a unilateral hypobaric spinal anesthesia was performed using 5 mg of bupivacaine in a 1.5 mL volume and a slow and steady, "air-buffered", directed injection technique, to allow an urgent hip arthroplasty. During surgery the patient was kept in the lateral recumbent position. Hemodynamics remained stable throughout the entire procedure without any need for vasoconstrictors. The impact of aortic valve stenosis combined with atrial fibrillation on anesthetic management and our considerations to opt for a unilateral hypobaric spinal anesthesia are discussed.

Onset of pi(0) suppression studied in Cu+Cu collisions at sqrt S NN=22.4, 62.4, and 200 GeV

Neutral pion transverse momentum (p(T)) spectra at midrapidity (|y| less than or approximately 0.35) were measured in Cu+Cu collisions at sqrt[s(NN)]=22.4, 62.4, and 200 GeV. Relative to pi_(0) yields in p+p collisions scaled by the number of inelastic nucleon-nucleon collisions (N(coll) the pi_(0) yields for p(T) more than or approximately 2 GeV/c in central Cu+Cu collisions are suppressed at 62.4 and 200 GeV whereas an enhancement is observed at 22.4 GeV. A comparison with a jet-quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.