982 research outputs found
The safety and effectiveness of chenodeoxycholic acid treatment in patients withcerebrotendinous xanthomatosis:two retrospective cohort studies.
Objective: To evaluate the safety and effectiveness of chenodeoxycholic acid (CDCA) treatment in patients with cerebrotendinous xanthomatosis (CTX). Methods: Two retrospective cohort studies were conducted in CTX patients who underwent CDCA treatment: one in the Netherlands (NL; CDCA-STUK-15-001) and one in Italy (IT; CDCA-STRCH-CR-14-001). Eligible patients were aged 2–75 years, had been diagnosed with CTX, and were treated with CDCA orally for ≥1 year. The impact of CDCA treatment on biochemical markers (including serum cholestanol levels) and disease signs and symptoms were assessed, in addition to the safety and tolerability of CDCA treatment. Results: A total of 35 patients were screened in the NL study and were diagnosed with CTX at 25.6 (± 13.7 SD) years on average. These patients were treated with CDCA and followed up for a median of 9.00 (range: 0.4–26.3) years. In addition, 28 patients were enrolled in the IT study and were diagnosed at 35.0 (± 11.4 SD) years on average (median duration of CDCA treatment: 5.75 [range: 0.0–25.0] years). Signs and symptoms of disease resolved, improved, or remained stable in many patients, with concomitant improvements in biochemical marker levels (serum cholestanol, p < 0.001; 7α-hydroxy-4-cholesten-3-one, p < 0.001 [IT study]). Conclusions: The outcomes of these retrospective cohort studies indicate that CDCA is effective in the long-term treatment of CTX, with an acceptable safety profile. © 2019, The Author(s)
The Mystery of the Asymptotic Quasinormal Modes of Gauss-Bonnet Black Holes
We analyze the quasinormal modes of -dimensional Schwarzschild black holes
with the Gauss-Bonnet correction in the large damping limit and show that
standard analytic techniques cannot be applied in a straightforward manner to
the case of infinite damping. However, by using a combination of analytic and
numeric techniques we are able to calculate the quasinormal mode frequencies in
a range where the damping is large but finite. We show that for this damping
region the famous appears in the real part of the quasinormal mode
frequency. In our calculations, the Gauss-Bonnet coupling, , is taken
to be much smaller than the parameter , which is related to the black hole
mass.Comment: 12 pages and 5 figure
Enhancing Chimeric Antigen Receptor T-Cell Efficacy in Solid Tumors
Chimeric antigen receptor (CAR) T-cell therapy has been acclaimed as a revolution in cancer treatment following the impressive results in hematologic malignancies. Unfortunately, in patients with solid tumors, objectives responses to CAR T cells are still anecdotal, and important issues are driven by on-target but off-tumor activity of CAR T cells and by the extremely complex biology of solid tumors. Here, we will review the recent attempts to challenge the therapeutic impediments to CAR T-cell therapy in solid tumors. We will focus on the most promising strategies of antigen targeting to improve tumor specificity and address the tumor heterogeneity, efforts to circumvent the physical barriers of the tumor architecture such as subverted tumor vasculature, impediments of CAR T-cell trafficking and immune suppressive microenvironment
Higher-Derivative Corrected Black Holes: Perturbative Stability and Absorption Cross-Section in Heterotic String Theory
This work addresses spherically symmetric, static black holes in
higher-derivative stringy gravity. We focus on the curvature-squared correction
to the Einstein-Hilbert action, present in both heterotic and bosonic string
theory. The string theory low-energy effective action necessarily describes
both a graviton and a dilaton, and we concentrate on the Callan-Myers-Perry
solution in d-dimensions, describing stringy corrections to the Schwarzschild
geometry. We develop the perturbation theory for the higher-derivative
corrected action, along the guidelines of the Ishibashi-Kodama framework,
focusing on tensor type gravitational perturbations. The potential obtained
allows us to address the perturbative stability of the black hole solution,
where we prove stability in any dimension. The equation describing
gravitational perturbations to the Callan-Myers-Perry geometry also allows for
a study of greybody factors and quasinormal frequencies. We address
gravitational scattering at low frequencies, computing corrections arising from
the curvature-squared term in the stringy action. We find that the absorption
cross-section receives \alpha' corrections, even though it is still
proportional to the area of the black hole event-horizon. We also suggest an
expression for the absorption cross-section which could be valid to all orders
in \alpha'.Comment: JHEP3.cls, 29 pages; v2: added refs, minor corrections and additions;
v3: added more refs, more minor corrections and addition
Naked Singularity in a Modified Gravity Theory
The cosmological constant induced by quantum fluctuation of the graviton on a
given background is considered as a tool for building a spectrum of different
geometries. In particular, we apply the method to the Schwarzschild background
with positive and negative mass parameter. In this way, we put on the same
level of comparison the related naked singularity (-M) and the positive mass
wormhole. We discuss how to extract information in the context of a f(R)
theory. We use the Wheeler-De Witt equation as a basic equation to perform such
an analysis regarded as a Sturm-Liouville problem . The application of the same
procedure used for the ordinary theory, namely f(R)=R, reveals that to this
approximation level, it is not possible to classify the Schwarzschild and its
naked partner into a geometry spectrum.Comment: 8 Pages. Contribution given to DICE 2008. To appear in the
proceeding
Is there life inside black holes?
Bound inside rotating or charged black holes, there are stable periodic
planetary orbits, which neither come out nor terminate at the central
singularity. Stable periodic orbits inside black holes exist even for photons.
These bound orbits may be defined as orbits of the third kind, following the
Chandrasekhar classification of particle orbits in the black hole gravitational
field. The existence domain for the third kind orbits is rather spacious, and
thus there is place for life inside supermassive black holes in the galactic
nuclei. Interiors of the supermassive black holes may be inhabited by
civilizations, being invisible from the outside. In principle, one can get
information from the interiors of black holes by observing their white hole
counterparts.Comment: 11 pages, 5 figures; references adde
Eradication of neuroblastoma by T cells redirected with an optimized GD2-specific chimeric antigen receptor and interleukin-15
Purpose: A delay in encountering the cognate antigen while in the circulation, and the suboptimal costimulation received at the tumor site are key reasons for the limited activity of chimeric antigen receptor–redirected T cells (CAR-T) in solid tumors. We have explored the benefits of incorporating the IL15 cytokine within the CAR cassette to provide both a survival signal before antigen encounter, and an additional cytokine signaling at the tumor site using a neuroblastoma tumor model. Experimental Design: We optimized the construct for the CAR specific for the NB-antigen GD2 without (GD2.CAR) or with IL15 (GD2.CAR.15). We then compared the expansion, phenotype, and antitumor activity of T cells transduced with these constructs against an array of neuroblastoma cell lines in vitro and in vivo using a xenogeneic metastatic model of neuroblastoma. Results: We observed that optimized GD2.CAR.15-Ts have reduced expression of the PD-1 receptor, are enriched in stem cell–like cells, and have superior antitumor activity upon repetitive tumor exposures in vitro and in vivo as compared with GD2.CAR-Ts. Tumor rechallenge experiments in vivo further highlighted the role of IL15 in promoting enhanced CAR-T antitumor activity and survival, both in the peripheral blood and tissues. Finally, the inclusion of the inducible caspase-9 gene (iC9) safety switch warranted effective on demand elimination of the engineered GD2. CAR.15-Ts. Conclusions: Our results guide new therapeutic options for GD2.CAR-Ts in patients with neuroblastoma, and CAR-T development for a broad range of solid tumors
Massive binary black holes in galactic nuclei and their path to coalescence
Massive binary black holes form at the centre of galaxies that experience a
merger episode. They are expected to coalesce into a larger black hole,
following the emission of gravitational waves. Coalescing massive binary black
holes are among the loudest sources of gravitational waves in the Universe, and
the detection of these events is at the frontier of contemporary astrophysics.
Understanding the black hole binary formation path and dynamics in galaxy
mergers is therefore mandatory. A key question poses: during a merger, will the
black holes descend over time on closer orbits, form a Keplerian binary and
coalesce shortly after? Here we review progress on the fate of black holes in
both major and minor mergers of galaxies, either gas-free or gas-rich, in
smooth and clumpy circum-nuclear discs after a galactic merger, and in
circum-binary discs present on the smallest scales inside the relic nucleus.Comment: Accepted for publication in Space Science Reviews. To appear in hard
cover in the Space Sciences Series of ISSI "The Physics of Accretion onto
Black Holes" (Springer Publisher
Supermassive Black Hole Binaries: The Search Continues
Gravitationally bound supermassive black hole binaries (SBHBs) are thought to
be a natural product of galactic mergers and growth of the large scale
structure in the universe. They however remain observationally elusive, thus
raising a question about characteristic observational signatures associated
with these systems. In this conference proceeding I discuss current theoretical
understanding and latest advances and prospects in observational searches for
SBHBs.Comment: 17 pages, 4 figures. To appear in the Proceedings of 2014 Sant Cugat
Forum on Astrophysics. Astrophysics and Space Science Proceedings, ed.
C.Sopuerta (Berlin: Springer-Verlag
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