Role of splenectomy for immune thrombocytopenic purpura (ITP) in the era of new second-line therapies and in the setting of a high prevalence of HIV-associated ITP

Background. New agents are being used as second-line treatment for immune thrombocytopenia (ITP) and have brought into question the relevance of splenectomy for steroid-resistant ITP.Methods. We retrospectively analysed 73 patients who underwent splenectomy for ITP at our institution over an 11-year period. The median follow-up period was 25 months; patients with follow-up of <1 month were excluded. The outcomes of splenectomy were compared in HIV-positive v. HIV-negative patients.Results. The rate of complete response was 83%, and response was sustained for at least 1 year or until latest follow-up in 80% of patients. Twelve patients were HIV-positive. Splenectomy was laparoscopic in 43 patients (62%) with an overall 16% complication rate. The 90-day mortality rate was 1.38%. There was no statistically significant difference in response or complication rate in the HIV-positive patients. There was a statistically significant (p=0.017) poorer response to splenectomy in the patients with steroid-resistant ITP.Conclusion. Splenectomy is effective and safe irrespective of HIV status and remains an appropriate  second-line treatment for ITP. Further research is needed to corroborate our finding of lower response in patients who are steroid-resistant, as this might be a subgroup of patients who may benefit from  thrombopoietin agonists as second-line therapy

Measurement of J/Psi at forward and backward rapidity in p plus p, p plus Al, p + Au, and He-3+Au collisions at root s(NN)=200 GeV

Charmonium is a valuable probe in heavy-ion collisions to study the properties of the quark gluon plasma, and is also an interesting probe in small collision systems to study cold nuclear matter effects, which are also present in large collision systems. With the recent observations of collective behavior of produced particles in small system collisions, measurements of the modification of charmonium in small systems have become increasingly relevant. We present the results of J/Psi measurements at forward and backward rapidity in various small collision systems, p + p, p + Al, p + Au, and He-3+Au, at root s(NN) = 200 GeV. The results are presented in the form of the observable RAB, the nuclear modification factor, a measure of the ratio of the J/Psi invariant yield compared to the scaled yield in p + p collisions. We examine the rapidity, transverse momentum, and collision centrality dependence of nuclear effects on J/Psi production with different projectile sizes p and He-3, and different target sizes Al and Au. The modification is found to be strongly dependent on the target size, but to be very similar for p + Au and He-3+Au. However, for 0%-20% central collisions at backward rapidity, the modification factor for He-3+Au is found to be smaller than that for p + Au, with a mean fit to the ratio of 0.89 +/- 0.03(stat)+/- 0.08(syst), possibly indicating final state effects due to the larger projectile size.Peer reviewe

Polarization and cross section of midrapidity J/psi production in p plus p collisions at root s=510 GeV

The PHENIX experiment has measured the spin alignment for inclusive J/psi -> e(+) e(-) decays in protonproton collisions at root s = 510 GeV at midrapidity. The angular distributions have been measured in three different polarization frames, and the three decay angular coefficients have been extracted in a full two-dimensional analysis. Previously, PHENIX saw large longitudinal net polarization at forward rapidity at the same collision energy. This analysis at midrapidity, complementary to the previous PHENIX results, sees no sizable polarization in the measured transverse momentum range of 0.0 <p(T) <10.0 GeV/c. The results are consistent with a previous one-dimensional analysis at midrapidity at root s = 200 GeV. The transverse-momentum-dependent cross section for midrapidity J/psi production has additionally been measured, and after comparison to world data, a simple logarithmic dependence of the cross section on root s was found.Peer reviewe

Angular decay coefficients of J/psi mesons at forward rapidity from p plus p collisions at root s=510 GeV

We report the first measurement of the full angular distribution for inclusive J/psi -> mu(+)mu(-) decays in p + p collisions at root s = 510 GeV. The measurements are made for J/psi transverse momentum 2 <p(T) <10 GeV /c and rapidity 1.2 <y <2.2 in the Helicity, Collins-Soper, and Gottfried-Jackson reference frames. In all frames the polar coefficient lambda theta is strongly negative at low p(T) and becomes close to zero at high p(T), while the azimuthal coefficient lambda phi is close to zero at low p(T), and becomes slightly negative at higher p(T). The frame-independent coefficient lambda is strongly negative at all p(T) in all frames. The data are compared to the theoretical predictions provided by nonrelativistic quantum chromodynamics models.Peer reviewe

Production of b(b)over-bar at forward rapidity in p plus p collisions at root s=510 GeV

The cross section of bottom quark-antiquark (b (b) over bar) production in p + p collisions at root s = 510 GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider. The results are based on the yield of high mass, like-sign muon pairs measured within the PHENIX muon arm acceptance (1.2 mu +/-mu +/-)/dy = 0.16 +/- 0.01 (stat) +/- 0.02 (syst) +/- 0.02 (global) nb for like-sign muons in the rapidity and p(T) ranges 1.2 1 GeV/c, and dimuon mass of 5-10 GeV/c(2). The extrapolated total cross section at this energy for b (b) over bar production is 13.1 +/- 0.6 (stat) +/- 1.5 (syst) +/- 2.7 (global) mu b. The total cross section is compared to a perturbative quantum chromodynamics calculation and is consistent within uncertainties. The azimuthal opening angle between muon pairs from b (b) over bar decays and their p(T) distributions are compared to distributions generated using PS PYTHIA6, which includes next-to-leading order processes. The azimuthal correlations and pair p(T) distribution are not very well described by PYTHIA calculations, but are still consistent within uncertainties. Flavor creation and flavor excitation subprocesses are favored over gluon splitting.Peer reviewe

Measurement of phi-meson production at forward rapidity in p plus p collisions at root s=510 GeV and its energy dependence from root s=200 GeV to 7 TeVMeasurement of phi-meson production at forward rapidity in p plus p collisions at root s=510 GeV and its energy dependence from root s=200 GeV to 7 TeV

The PHENIX experiment at the Relativistic Heavy Ion Collider has measured the differential cross section of phi(1020)-meson production at forward rapidity in p + p collisions at root s = 510 GeV via the dimuon decay channel. The partial cross section in the rapidity and P-T ranges 1.2 <vertical bar y vertical bar <2.2 and 2 <p(T) <7 GeV/c is sigma(phi) = [2.28 +/- 0.09(stat) +/- 0.14(syst) +/- 0.27(norm)] x 10(-2) mb. The energy dependence of sigma(phi )(1.2 <vertical bar y vertical bar <2.2,2 <p(T) <5 GeV/c) is studied using the PHENIX measurements at root s = 200 and 510 GeV and the Large Hadron Collider measurements at root s = 2.76 and 7 TeV. The experimental results arc compared to various event generator predictions (PYTHIA6, PYTHIA8, PHOJET, AMPT, EPOS3, and EPOS-LHC).Peer reviewe

Measurement of the relative yields of psi(2S) to psi(1S) mesons produced at forward and backward rapidity in p plus p, p plus Al, p + Au, and He-3+Au collisions at root S-NN=200 GeV

The PHENIX Collaboration has measured the ratio of the yields of psi(2S) to psi(1S) mesons produced in p + p, p + Al, p + Au, and He-3+Au collisions at root S-NN = 200 GeV over the forward and backward rapidity intervals 1.2 <| y | <2.2. We find that the ratio in p + p collisions is consistent with measurements at other collision energies. In collisions with nuclei, we find that in the forward (p-going or He-3-going) direction, the relative yield of psi(2S) mesons to psi(1S) mesons is consistent with the value measured in p + p collisions. However, in the backward (nucleus-going) direction, the psi(2S) meson is preferentially suppressed by a factor of similar to 2. This suppression is attributed in some models to the breakup of the weakly bound psi(2S) meson through final-state interactions with comoving particles, which have a higher density in the nucleus-going direction. These breakup effects may compete with color screening in a deconfined quark-gluon plasma to produce sequential suppression of excited quarkonia states.Peer reviewe

Multiparticle azimuthal correlations for extracting event-by-event elliptic and triangular flow in Au plus Au collisions at root S-NN=200 GeV

We present measurements of elliptic and triangular azimuthal anisotropy of charged particles detected at forward rapidity 1 < vertical bar eta vertical bar < 3 in Au + Au collisions at root S-NN = 200 GeV, as a function of centrality. The multiparticle cumulant technique is used to obtain the elliptic flow coefficients v(2){2}, v(2){4}, v(2){6}, and v(2){8}, and triangular flow coefficients v(3){2} and v(3){4}. Using the small-variance limit, we estimate the mean and variance of the event-by-event v 2 distribution from v(2){2} and v(2){4}. In a complementary analysis, we also use a folding procedure to study the distributions of v(2) and v(3) directly, extracting both the mean and variance. Implications for initial geometrical fluctuations and their translation into the final-state momentum distributions are discussed.Peer reviewe

Measurement of emission-angle anisotropy via long-range angular correlations with high-pT hadrons in d plus Au and p plus p collisions at root s(NN)=200 GeV

We present measurements of two-particle angular correlations between high-transverse-momentum (2 <pT <11 GeV/c) pi(0) observed at midrapidity (|eta| <0.35) and particles produced either at forward (3.1 <eta <3.9) or backward (-3.7 <eta <-3.1) rapidity in d + Au and p + p collisions at root s(NN) = 200 GeV. The azimuthal angle correlations for particle pairs with this large rapidity gap in the Au-going direction exhibit a characteristic structure that persists up to pT approximate to 6 GeV/c and which strongly depends on collision centrality, which is a similar characteristic to the hydrodynamical particle flow in A + A collisions. The structure is absent in the d-going direction as well as in p + p collisions, in the transverse-momentum range studied. The results indicate that the structure is shifted in the Au-going direction toward more central collisions, similar to the charged-particle pseudorapidity distributions.Peer reviewe

Measurement of charged pion double spin asymmetries at midrapidity in longitudinally polarized p plus p collisions at root s=510 GeV

The PHENIX experiment at the Relativistic Heavy Ion Collider has measured the longitudinal double spin asymmetries, A(LL), for charged pions at midrapidity (vertical bar eta vertical bar <0.35) in longitudinally polarized p + p collisions at root s. = 510 GeV. These measurements are sensitive to the gluon spin contribution to the total spin of the proton in the parton momentum fraction x range between 0.04 and 0.09. One can infer the sign of the gluon polarization from the ordering of pion asymmetries with charge alone. The asymmetries are found to be consistent with global quantum-chromodynamics fits of deep-inelastic scattering and data at root s = 200 GeV, which show a nonzero positive contribution of gluon spin to the proton spin.Peer reviewe