6,218 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
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
Voluminous plexiform neurofibromas of the neck region in neurofibromatosis 1
Objetivo. Presentar las características clínicas, de imagen y evolutivas de una serie de pacientes con neurofibromatosis
tipo 1 que desarrollaron durante la infancia neurofibromas plexiformes voluminosos en el cuello (NFPVC).
Pacientes y métodos. Nueve pacientes (cinco mujeres y cuatro varones) con edades entre 3 y 15 años en el momento del
diagnóstico de los tumores, que podían extenderse también a la fosa posterior y a la zona torácica superior. El diagnóstico
estuvo basado fundamentalmente en la clínica, la imagen y la histología.
Resultados. Un tumor era intralaríngeo y causaba problemas respiratorios. Los otros ocho casos tenían su origen en varias
raíces espinales de uno o de ambos lados y podían crecer también hacia el interior de la fosa posterior y de la región
torácica en algunos pacientes, y desplazaban a las estructuras anatómicas vecinas, especialmente en tres casos, todos niñas,
en las que el tumor creció hasta alcanzar gran volumen, especialmente por un lado, parándose el crecimiento entre
los 11 y 12 años y no volviendo a crecer más tarde.
Conclusiones. Los NFPVC son tumores histológicamente benignos. La extirpación es necesaria cuando están localizados
en la laringe por los problemas respiratorios que causan, pero no en los de las otras regiones, pese a que el voluminoso
tamaño que alcanzan en algunos casos puede causar exagerados desplazamientos de las estructuras vecinas. El estudio
de nuestra serie parece indicar que al menos los tumores extralaríngeos sólo crecen hasta los 11-12 años. Puede ser recomendable
retrasar la cirugía tanto como sea posible si no existe sintomatología aguda que la haga necesariaAim. To present the clinic, imaging and evolutive characteristics of a series of patients with neurofibromatosis 1 with voluminous
plexiform neurofibromas in the neck (VPNFN) during childhood.
Patients and methods. Nine patients (five females and four males) who were diagnosed as VPNFN at ages between 3 and 15
years. The VPNFN widespread to the posterior fossa or the upper thoracic region in some cases. The diagnosis was based
on the clinical, imaging and histological findings.
Results. One of the tumors was intralaryngeal and caused respiratory difficulties. The other eight patients had the origin
of the tumor in several spinal roots of one or both sides and could growth to the posterior fossa and to the upper thoracic
region in some cases with displacement of the surrounding organs, especially in three patients, all girls, in whom the
tumor reached a voluminous size on one side, that was observed only until 10 to 11 years when the growth ceased.
Conclusions. The VPNFN are histologically benign tumors. Those located in the larynx must be removed because of the
respiratory problems, but it is not necessary in cases with other locations despite the voluminous size that can reach in some
patients with great displacement of the surrounding organs. The analysis of the results of our series may demonstrate that
al least the extralaryngeal tumors only grow to 11-12 years of age. This possibility may make recommendable to retard the
surgical treatment as much as possible in cases that it is not necessar
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
Long-range repulsive interaction between TTF molecules on a metal surface induced by charge transfer
The low-coverage adsorption of a molecular electron donor,
tetrathiafulvalene, on Au(111) is characterized by the spontaneous formation of
superlattice of monomers, whose spacing exceeds the equilibrium distance of
non-covalent interactions and depends on coverage. The origin of this peculiar
growth mode is due to a long-range repulsive interaction between molecules. The
analysis of molecular-pair distributions obtained by scanning tunneling
microscopy measurements permits us to determine that the nature of TTF
intermolecular interactions on Au (111) is electrostatic. A repulsion between
molecules is caused by the accumulation of charge due to electron donation into
the metal surface, as pictured through density functional theory calculations
Unconventional spin texture of a topologically nontrivial semimetal Sb(110)
The surfaces of antimony are characterized by the presence of spin-split
states within the projected bulk band gap and the Fermi contour is thus
expected to exhibit a spin texture. Using spin-resolved density functional
theory calculations, we determine the spin polarization of the surface bands of
Sb(110). The existence of the unconventional spin texture is corroborated by
the investigations of the electron scattering on this surface. The charge
interference patterns formed around single scattering impurities, imaged by
scanning tunneling microscopy, reveal the absence of direct backscattering
signal. We identify the allowed scattering vectors and analyze their bias
evolution in relation to the surface-state dispersion.Comment: 10 pages, 5 figure
OP07.05: Recurrence rate after ultrasound‐guided transvaginal aspiration of benign adnexal masses with and without sclerotherapy: a systematic review and meta‐analysis
Minimal optimal generalized quantum measurements
Optimal and finite positive operator valued measurements on a finite number
of identically prepared systems have been presented recently. With physical
realization in mind we propose here optimal and minimal generalized quantum
measurements for two-level systems.
We explicitly construct them up to N=7 and verify that they are minimal up to
N=5. We finally propose an expression which gives the size of the minimal
optimal measurements for arbitrary .Comment: 9 pages, Late
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