29 research outputs found
Leg Ulcers: A Report in Patients with Hemoglobin E Beta Thalassemia and Review of the Literature in Severe Beta Thalassemia
BACKGROUND
Leg ulcers are a frequent complication in patients with the inherited hemoglobin disorders. In thalassemia, the literature is limited, and factors associated with the development of leg ulcers in HbE beta thalassemia, the most common form of severe beta thalassemia worldwide, have not previously been reported.
METHODS
We reviewed all available medical records of patients with HbE beta thalassemia to document the onset of leg ulcers at the two largest treatment centres in Sri Lanka. We reviewed the literature to identify studies reporting outcomes of interventions for ulcers in severe thalassemia.
RESULTS
Of a total of 255 actively registered patients with HbE thalassemia in the two centres, 196 patient charts were evaluable. A leg ulcer with a documented date of onset was recorded in 45 (22%) of 196 evaluable patients, aged (mean ± SEM) 22.2 ± 1.4 years. Most had been irregularly transfused; steady state hemoglobin was 6.4 ± 0.2 g/dL. Treatment achieving healing in 17 patients included transfusions, antibiotics, oral zinc, wound toileting and skin grafting.
DISCUSSION/CONCLUSION
Leg ulcers may be more common in HbE beta thalassemia than in other forms of thalassemia. A systematic approach to treatment will be needed to document the prevalence and factors placing such patients at risk for leg ulcers. Controlled trials to evaluate the optimal treatment of this common complication are indicated
Survival and complications in patients with haemoglobin E thalassaemia in Sri Lanka: a prospective, longitudinal cohort study
BACKGROUND
Worldwide, haemoglobin E β-thalassaemia is the most common genotype of severe β-thalassaemia. The paucity of long-term data for this form of thalassaemia makes evidence-based management challenging. We did a long-term observational study to define factors associated with survival and complications in patients with haemoglobin E thalassaemia.
METHODS
In this prospective, longitudinal cohort study, we included all patients with haemoglobin E thalassaemia who attended the National Thalassaemia Centre in Kurunegala, Sri Lanka, between Jan 1, 1997, and Dec 31, 2001. Patients were assessed up to three times a year. Approaches to blood transfusions, splenectomy, and chelation therapy shifted during this period. Survival rates between groups were evaluated using Kaplan-Meier survival function estimate curves and Cox proportional hazards models were used to identify risk factors for mortality.
FINDINGS
109 patients (54 [50%] male; 55 [50%] female) were recruited and followed up for a median of 18 years (IQR 14-20). Median age at recruitment was 13 years (range 8-21). 32 (29%) patients died during follow-up. Median survival in all patients was 49 years (95% CI 45-not reached). Median survival was worse among male patients (hazard ratio [HR] 2·51, 95% CI 1·16-5·43), patients with a history of serious infections (adjusted HR 8·49, 2·90-24·84), and those with higher estimated body iron burdens as estimated by serum ferritin concentration (adjusted HR 1·03, 1·01-1·06 per 100 units). Splenectomy, while not associated with statistically significant increases in the risks of death or serious infections, ultimately did not eliminate a requirement for scheduled transfusions in 42 (58%) of 73 patients. Haemoglobin concentration less than or equal to 4·5 g/dL (vs concentration >4·5 g/dL), serum ferritin concentration more than 1300 μg/L (vs concentration ≤1300 μg/L), and liver iron concentration more than 5 mg/g dry weight of liver (vs concentration ≤5 mg/g) were associated with poorer survival.
INTERPRETATION
Patients with haemoglobin E thalassaemia often had complications and shortened survival compared with that reported in high-resource countries for thalassaemia major and for thalassaemia intermedia not involving an allele for haemoglobin E. Approaches to management in this disorder remain uncertain and prospective studies should evaluate if altered transfusion regimens, with improved control of body iron, can improve survival.
FUNDING
Wellcome Trust, Medical Research Council, US March of Dimes, Anthony Cerami and Ann Dunne Foundation for World Health, and Hemoglobal
meson production in Au collisions at GeV
The PHENIX experiment has measured meson production in Au
collisions at GeV using the dimuon and dielectron decay
channels. The meson is measured in the forward (backward) -going
(Au-going) direction, () in the transverse-momentum
() range from 1--7 GeV/, and at midrapidity in the
range below 7 GeV/. The meson invariant yields and
nuclear-modification factors as a function of , rapidity, and centrality
are reported. An enhancement of meson production is observed in the
Au-going direction, while suppression is seen in the -going direction, and
no modification is observed at midrapidity relative to the yield in
collisions scaled by the number of binary collisions. Similar behavior was
previously observed for inclusive charged hadrons and open heavy flavor
indicating similar cold-nuclear-matter effects.Comment: 484 authors, 16 pages, 12 figures, 6 tables. v1 is the version
accepted for publication in Phys. Rev. C. Data tables for the points plotted
in the figures are given in the paper itsel
Cross Section and Transverse Single-Spin Asymmetry of Mesons in Collisions at GeV at Forward Rapidity
We present a measurement of the cross section and transverse single-spin
asymmetry () for mesons at large pseudorapidity from
~GeV collisions. The measured cross section for
~GeV/ and is well described by a
next-to-leading-order perturbative-quantum-chromodynamics calculation. The
asymmetries have been measured as a function of Feynman- () from
, as well as transverse momentum () from
~GeV/. The asymmetry averaged over positive is
. The results are consistent with prior
transverse single-spin measurements of forward and mesons at
various energies in overlapping ranges. Comparison of different particle
species can help to determine the origin of the large observed asymmetries in
collisions.Comment: 484 authors, 13 pages, 11 figures, 4 tables, 2008 data. v2 is version
accepted by Phys. Rev. D. Plain text data tables for the points plotted in
figures for this and previous PHENIX publications are (or will be)publicly
available at http://www.phenix.bnl.gov/papers.htm
Measurements of elliptic and triangular flow in high-multiplicity HeAu collisions at GeV
We present the first measurement of elliptic () and triangular ()
flow in high-multiplicity HeAu collisions at
GeV. Two-particle correlations, where the particles have a large separation in
pseudorapidity, are compared in HeAu and in collisions and
indicate that collective effects dominate the second and third Fourier
components for the correlations observed in the HeAu system. The
collective behavior is quantified in terms of elliptic and triangular
anisotropy coefficients measured with respect to their corresponding
event planes. The values are comparable to those previously measured in
Au collisions at the same nucleon-nucleon center-of-mass energy.
Comparison with various theoretical predictions are made, including to models
where the hot spots created by the impact of the three 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.Comment: 630 authors, 9 pages, 4 figures, 2 tables. v2 is the version accepted
for publication by Physical Review Letters. Plain text data tables for the
points plotted in figures for this and previous PHENIX publications are (or
will be) publicly available at http://www.phenix.bnl.gov/papers.htm
Transverse energy production and charged-particle multiplicity at midrapidity in various systems from to 200 GeV
Measurements of midrapidity charged particle multiplicity distributions,
, and midrapidity transverse-energy distributions,
, are presented for a variety of collision systems and energies.
Included are distributions for AuAu collisions at ,
130, 62.4, 39, 27, 19.6, 14.5, and 7.7 GeV, CuCu collisions at
and 62.4 GeV, CuAu collisions at
GeV, UU collisions at GeV,
Au collisions at GeV, HeAu collisions at
GeV, and collisions at
GeV. Centrality-dependent distributions at midrapidity are presented in terms
of the number of nucleon participants, , and the number of
constituent quark participants, . For all collisions
down to GeV, it is observed that the midrapidity data
are better described by scaling with than scaling with . Also presented are estimates of the Bjorken energy density,
, and the ratio of to ,
the latter of which is seen to be constant as a function of centrality for all
systems.Comment: 706 authors, 32 pages, 20 figures, 34 tables, 2004, 2005, 2008, 2010,
2011, and 2012 data. v2 is version accepted for publication in Phys. Rev.
Measurement of and in , Au, and CuCu collisions at GeV
The PHENIX experiment at the Relativistic Heavy Ion Collider has performed a
systematic study of and meson production at midrapidity in
, Au, and CuCu collisions at GeV. The
and mesons are reconstructed via their and decay modes, respectively. The measured
transverse-momentum spectra are used to determine the nuclear modification
factor of and mesons in Au and CuCu collisions at
different centralities. In the Au collisions, the nuclear modification
factor of and mesons is almost constant as a function of
transverse momentum and is consistent with unity showing that
cold-nuclear-matter effects do not play a significant role in the measured
kinematic range. In CuCu collisions, within the uncertainties no nuclear
modification is registered in peripheral collisions. In central collisions,
both mesons show suppression relative to the expectations from the
yield scaled by the number of binary nucleon-nucleon collisions in the CuCu
system. In the range 2--5 GeV/, the strange mesons (, )
similarly to the meson with hidden strangeness, show an intermediate
suppression between the more suppressed light quark mesons () and the
nonsuppressed baryons (, ). At higher transverse momentum,
GeV/, production of all particles is similarly suppressed by a factor of
2.Comment: 590 authors, 22 pages, 14 figures, 5 tables. Submitted to Phys. Rev.
C Plain text data tables for the points plotted in figures for this and
previous PHENIX publications are (or will be) publicly available at
http://www.phenix.bnl.gov/papers.htm