1,122 research outputs found
Causes of death after liver transplantation in children treated with cyclosporine and steroids
Two-hundred-and-twenty-seven children underwent orthotopic liver transplantation between March 1980 and March 1986. Seventy (31%) patients died during the study period. Four patients who died within 24 hours of the initial liver transplant and 5 patients who died outside of our institution were excluded from the analysis. Liver failure, related to either thrombosis of the hepatic artery, primary non-function of the graft or rejection accounted for 25 of the remaining 61 deaths. In 21 patients death was related to overwheming sepsis while 7 patients died from excessive bleeding. Eight of the deaths were due to a miscellaneous group of causes. Twenty percent of the 150 patients who received a single liver transplant died compared to a death rate of 50% in patients who underwent three transplants. Eighty-five percent of the deaths occurred within 6 months after the initial liver transplant. Liver failure was the cause in the majority of the early deaths whereas the later deaths were more likely to be due to sepsis. This detailed analysis of the causes of death after pediatric liver transplantation in a large group of patients has revealed that advances in certain areas could lead to even better results
Causas de muerte posterior al trasplante hepatico en ninos tratados con ciclosporina y esteroides
Isospora araponga sp. n. (Apicomplexa: Eimeriidae), a new species of Isospora Schneider from a bare-throated bellbird, Procnias nudicollis (Vieillot, 1817) (Passeriformes: Cotingidae) from Brazil
Transmission Spectra of Transiting Planet Atmospheres: Model Validation and Simulations of the Hot Neptune GJ 436b for JWST
We explore the transmission spectrum of the Neptune-class exoplanet GJ 436b,
including the possibility that its atmospheric opacity is dominated by a
variety of non- equilibrium chemical products. We also validate our
transmission code by demonstrating close agreement with analytic models that
use only Rayleigh scattering or water vapor opacity. We find broad disagreement
with radius variations predicted by another published model. For GJ 436b, the
relative coolness of the planet's atmosphere, along with its implied high
metallicity, may make it dissimilar in character compared to "hot Jupiters."
Some recent observational and modeling efforts suggest low relative abundances
of H2O and CH4 present in GJ 436b's atmosphere, compared to calculations from
equilibrium chemistry. We include these characteristics in our models and
examine the effects of absorption from methane-derived higher order
hydrocarbons. Significant absorption from HCN and C2H2 are found throughout the
infrared, while C2H4 and C2H6 are less easily seen. We perform detailed
simulations of JWST observations, including all likely noise sources, and find
that we will be able to constrain chemical abundance regimes from this planet's
transmission spectrum. For instance, the width of the features at 1.5, 3.3, and
7 microns indicates the amount of HCN versus C2H2 present. The NIRSpec prism
mode will be useful due to its large spectral range and the relatively large
number of photo-electrons recorded per spectral resolution element. However,
extremely bright host stars like GJ 436 may be better observed with a higher
spectroscopic resolution mode in order to avoid detector saturation. We find
that observations with the MIRI low resolution spectrograph should also have
high signal-to-noise in the 5 - 10 micron range due to the brightness of the
star and the relatively low spectral resolution (R ~ 100) of this mode.Comment: 33 pages, 12 figures, Accepted to Ap
A search for diffuse bands in the circumstellar envelopes of post-AGB stars
In this work we present the results of a systematic search for diffuse bands
(DBs, hereafter) in the circumstellar envelopes of a carefully selected sample
of post-AGB stars. We concentrated on the analysis of 9 of the DBs most
commonly found in the interstellar medium. The strength of these features is
determined using high resolution optical spectroscopy and the results obtained
are compared with literature data on field stars affected only by interstellar
reddening. Based on the weak features observed in the subsample of post-AGB
stars dominated by circumstellar reddening we conclude that the carrier(s) of
these DBs must not be present in the circumstellar environment of these
sources, or at least not under the excitation conditions in which DBs are
formed. The conclusion is applicable to all the post-AGB stars studied,
irrespective of the dominant chemistry or the spectral type of the star
considered. A detailed radial velocity analysis of the features observed in
individual sources confirms this result, as the Doppler shifts measured are
found to be consistent with an interstellar origin.Comment: Accepted for A&
Three new species of Isospora Schneider, 1881 (Apicomplexa: Eimeriidae) from the double-collared seed eater, Sporophila caerulescens (Passeriformes: Emberizidae), from Eastern Brazil
Global Proteome and Phospho-proteome Analysis of Merlin-deficient Meningioma and Schwannoma Identifies PDLIM2 as a Novel Therapeutic Target
Loss or mutation of the tumour suppressor Merlin predisposes individuals to develop multiple nervous system tumours, including schwannomas and meningiomas, sporadically or as part of the autosomal dominant inherited condition Neurofibromatosis 2 (NF2). These tumours display largely low grade features but their presence can lead to significant morbidity. Surgery and radiotherapy remain the only treatment options despite years of research, therefore an effective therapeutic is required.
Unbiased omics studies have become pivotal in the identification of differentially expressed genes and proteins that may act as drug targets or biomarkers. Here we analysed the proteome and phospho-proteome of these genetically defined tumours using primary human tumour cells to identify upregulated/activated proteins and/or pathways. We identified over 2000 proteins in comparative experiments between Merlin-deficient schwannoma and meningioma compared to human Schwann and meningeal cells respectively. Using functional enrichment analysis we highlighted several dysregulated pathways and Gene Ontology terms. We identified several proteins and phospho-proteins that are more highly expressed in tumours compared to controls. Among proteins jointly dysregulated in both tumours we focused in particular on PDZ and LIM domain protein 2 (PDLIM2) and validated its overexpression in several tumour samples, while not detecting it in normal cells. We showed that shRNA mediated knockdown of PDLIM2 in both primary meningioma and schwannoma leads to significant reductions in cellular proliferation.
To our knowledge, this is the first comprehensive assessment of the NF2-related meningioma and schwannoma proteome and phospho-proteome. Taken together, our data highlight several commonly deregulated factors, and indicate that PDLIM2 may represent a novel, common target for meningioma and schwannoma
Accreting Millisecond X-Ray Pulsars
Accreting Millisecond X-Ray Pulsars (AMXPs) are astrophysical laboratories
without parallel in the study of extreme physics. In this chapter we review the
past fifteen years of discoveries in the field. We summarize the observations
of the fifteen known AMXPs, with a particular emphasis on the multi-wavelength
observations that have been carried out since the discovery of the first AMXP
in 1998. We review accretion torque theory, the pulse formation process, and
how AMXP observations have changed our view on the interaction of plasma and
magnetic fields in strong gravity. We also explain how the AMXPs have deepened
our understanding of the thermonuclear burst process, in particular the
phenomenon of burst oscillations. We conclude with a discussion of the open
problems that remain to be addressed in the future.Comment: Review to appear in "Timing neutron stars: pulsations, oscillations
and explosions", T. Belloni, M. Mendez, C.M. Zhang Eds., ASSL, Springer;
[revision with literature updated, several typos removed, 1 new AMXP added
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