12,766 research outputs found
Treatment with antisense oligonucleotides in Duchenne’s disease
Se revisa el estado actual de los tratamientos de modificación del ARN de distrofina, que persiguen convertir
la forma grave de la distrofia muscular de Duchenne a una forma leve (Becker), especialmente con la omisión del exón
51 mediante oligonucleótidos en antisentido y la terapia de restauración de la lectura de la distrofina, suprimiendo un
codón de terminación prematura mediante PTC124. Constituyen un avance notable en el tratamiento. Consiguen una
producción significativa de distrofina en el músculo esquelético, aunque, por el momento, los resultados clínicos son menos
notables. Es de esperar que modificaciones químicas en la liberación y distribución corporal, así como en la captación
celular de estos oligonucleótidos, aumenten su eficacia y seguridad, permitiendo el tratamiento crónico de la distrofia
muscular de DuchenneIn this paper I review the results of the treatments directed to modify the mRNA of dystrophin with the goal of
converting the severe Duchenne type to the milder Becker muscular dystrophy. Antisense oligomers potential to modify
Duchenne muscular dystrophy (DMD) gene expression and therapeutic strategies to induce ribosomal read-through of
nonsense mutations (PTC124) are described. They are an important advance in the treatment of DMD, so far unspecific.
Significant expression of new dystrophin is observed in biopsies of peripheral muscle, although the functional improvement
is not so encouraging. New modification of chemistries are expected to improve the liberation, broad distribution in
muscles, as well as their efficacy and safety enough to allow a positive chronic treatment of DM
Research on WASH sector, environment and water resources in the Central Rift Valley of Ethiopia
Peer ReviewedPostprint (published version
Stars and brown dwarfs in the sigma Orionis cluster. III. OSIRIS/GTC low-resolution spectroscopy of variable sources
Context. Although many studies have been performed so far, there are still
dozens of low-mass stars and brown dwarfs in the young sigma Orionis open
cluster without detailed spectroscopic characterisation. Aims. We look for
unknown strong accretors and disc hosts that were undetected in previous
surveys. Methods. We collected low-resolution spectroscopy (R ~ 700) of ten
low-mass stars and brown dwarfs in sigma Orionis with OSIRIS at the Gran
Telescopio Canarias under very poor weather conditions. These objects display
variability in the optical, infrared, Halpha, and/or X-rays on time scales of
hours to years. We complemented our spectra with optical and near-/mid-infrared
photometry. Results. For seven targets, we detected lithium in absorption,
identified Halpha, the calcium doublet, and forbidden lines in emission, and/or
determined spectral types for the first time. We characterise in detail a
faint, T Tauri-like brown dwarf with an 18 h-period variability in the optical
and a large Halpha equivalent width of -125+/-15 AA, as well as two M1-type,
X-ray-flaring, low-mass stars, one with a warm disc and forbidden emission
lines, the other with a previously unknown cold disc with a large inner hole.
Conclusions. New unrevealed strong accretors and disc hosts, even below the
substellar limit, await discovery among the list of known sigma Orionis stars
and brown dwarfs that are variable in the optical and have no detailed
spectroscopic characterisation yet.Comment: A&A, in press (accepted for publication in section 14. Catalogs and
data of Astronomy and Astrophysics
Corpus callosum tumor as the presenting symptom of neurofibromatosis type 1 in a patient and literature review
Introducción. La neurofibromatosis tipo 1 (NF1) es uno de los síndromes neurocutáneos más frecuentes y puede asociarse
a tumores intracraneales en cualquier localización, pero excepcionalmente en el cuerpo calloso.
Objetivos. Presentar un caso de NF1 que se manifiesta como un tumor de cuerpo calloso y llevar a cabo una revisión de la
incidencia de tumores del cuerpo calloso en nuestra casuística y en la bibliografía.
Caso clínico. Niño visto desde los 3 años con criterios diagnósticos de NF1 (sin comprobación genética), que fue estudiado
por resonancia magnética (RM) y RM espectroscópica. La RM mostró objetos brillantes en la neurofibromatosis en
diversas zonas cerebrales y cerebelosas, posible tumor en el tronco cerebral (parte bulbar) y tumor en la zona derecha
del esplenio del cuerpo calloso. La RM espectroscópica del posible tumor del tronco mostró hallazgos compatibles con
tumoración glial de bajo grado. Se siguió su evolución hasta los 19 años sin que hubieran existido cambios clínicos ni en
el tamaño de los tumores en las dos localizaciones. Sólo existen seis casos publicados de tumor del cuerpo calloso en
pacientes con NF1.
Conclusión. Presentamos un nuevo caso de un paciente con tumor del cuerpo calloso en un paciente con NF1. Las características
de la imagen y la evolución clínica van a favor del carácter benigno de este tipo de tumorIntroduction. Neurofibromatosis type 1 (NF1) is one of the most frequent neurocutaneous syndromes. NF1 can be associated
with intracranial tumors in any location, but only rarely in the corpus callosum.
Aims. To describe a case of NF1 presenting as a tumor of the corpus callosum and to carry out a review of the incidence of
the tumors of corpus callosum in our series and in the literature.
Case report. We present a child who was studied since 3 years of age because of complete NF1 clinical diagnostic criteria
(without genetic study). He was studied by MR and magnetic resonance spectroscopy (MRS). MR study showed neurofibromatosis
bright objects distributed over several regions of the cerebral hemispheres and cerebellum, a possible brain
stem tumor (bulbar zone) and the splenium of the corpus callosum. The MRS of the brain stem tumor showed changes
consistent with a low grade glial tumor. The patient was followed until 19-years of age without demonstrating any changes in
the clinical features or the tumor size in both locations Only six cases of corpus callosum tumor in patients with NF1 have
been published to date.
Conclusions. We present a new case with tumor of the corpus callosum and NF1. The imaging characteristics and the
clinical course were in favour of the benign nature of this type of tumo
Optimal generalized quantum measurements for arbitrary spin systems
Positive operator valued measurements on a finite number of N identically
prepared systems of arbitrary spin J are discussed. Pure states are
characterized in terms of Bloch-like vectors restricted by a SU(2 J+1)
covariant constraint. This representation allows for a simple description of
the equations to be fulfilled by optimal measurements. We explicitly find the
minimal POVM for the N=2 case, a rigorous bound for N=3 and set up the analysis
for arbitrary N.Comment: LateX, 12 page
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