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1.
Brain ; 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38489591

RESUMEN

Leukodystrophies are rare genetic white matter disorders that have been regarded as mainly occurring in childhood. Recent years altered this perception, as a growing number of leukodystrophies was described to have an onset at adult ages. Still, many adult patients presenting with white matter changes remain without a specific molecular diagnosis. We describe a novel adult onset leukodystrophy in 16 patients from eight families carrying one of four different stop-gain or frameshift dominant variants in the CST3 gene. Clinical and radiological features differ markedly from the previously described Icelandic Cerebral Amyloid Angiopathy that was found in patients carrying p.Leu68Asn substitution in CST3. The clinical phenotype consists of recurrent episodes of hemiplegic migraine associated with transient unilateral focal deficits and slowly progressing motor symptoms and cognitive decline in mid-old adult ages. In addition, in some cases acute onset clinical deterioration led to a prolonged episode with reduced consciousness and even early death. Radiologically, pathognomonic changes are found at typical predilection sites involving the deep cerebral white matter sparing a periventricular and directly subcortical rim, the middle blade of corpus callosum, posterior limb of the internal capsule, middle cerebellar peduncles, cerebral peduncles, and specifically the globus pallidus. Histopathologic characterization in two autopsy cases did not reveal angiopathy, but instead micro- to macrocystic degeneration of the white matter. Astrocytes were activated at early stages and later on displayed severe degeneration and loss. In addition, despite loss of myelin, elevated numbers of partly apoptotic oligodendrocytes were observed. A structural comparison of the variants in CST3 suggests that specific truncations of Cystatin C result in an abnormal function, possibly by rendering the protein more prone to aggregation. Future studies are required to confirm the assumed effect on the protein and to determine pathophysiologic downstream events at the cellular level.

3.
Neurotherapeutics ; 20(6): 1820-1834, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37733208

RESUMEN

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease affecting upper and lower motor neurons (MNs). Neuregulin-1 (NRG1) is a pleiotropic growth factor that has been shown to be potentially valuable for ALS when supplemented by means of viral-mediated gene therapy. However, these results are inconsistent with other reports. An alternative approach for investigating the therapeutic impact of NRG1 on ALS is the use of transgenic mouse lines with genetically defined NRG1 overexpression. Here, we took advantage of a mouse line with NRG1 type III overexpression in spinal cord α motor neurons (MN) to determine the impact of steadily enhanced NRG1 signalling on mutant superoxide dismutase 1 (SOD1)-induced disease. The phenotype of SOD1G93A-NRG1 double transgenic mice was analysed in detail, including neuropathology and extensive behavioural testing. At least 3 animals per condition and sex were histopathologically assessed, and a minimum of 10 mice per condition and sex were clinically evaluated. The accumulation of misfolded SOD1 (mfSOD1), MN degeneration, and a glia-mediated neuroinflammatory response are pathological hallmarks of ALS progression in SOD1G93A mice. None of these aspects was significantly improved when examined in double transgenic NRG1-SOD1G93A mice. In addition, behavioural testing revealed that NRG1 type III overexpression did not affect the survival of SOD1G93A mice but accelerated disease onset and worsened the motor phenotype.


Asunto(s)
Esclerosis Amiotrófica Lateral , Enfermedades Neurodegenerativas , Ratones , Animales , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/terapia , Esclerosis Amiotrófica Lateral/metabolismo , Superóxido Dismutasa-1/genética , Neurregulina-1/genética , Enfermedades Neurodegenerativas/metabolismo , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Neuronas Motoras/patología , Ratones Transgénicos
4.
Eur J Surg Oncol ; 48(5): 1181-1187, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34782183

RESUMEN

INTRODUCTION: The diagnostic role of lymph node (LN) assessment is established in endometrial cancer. Our study assesses whether surgical removal of metastatic LNs has oncologic benefit in high-grade endometrial cancer. MATERIALS AND METHODS: High-grade endometrial cancer cases (2000-2010) were collected from two tertiary cancer centres. In patients with at least one positive LN, recurrence free survival (RFS) was compared by the number of LNs removed. Factors predicting nodal recurrence (NR) were explored. Univariate statistical analyses by log rank test and multivariable cox proportional hazards model were performed using SAS version 9.4. RESULTS: Of 570 patients identified, 334 patients underwent staging lymphadenectomy, 74 (22.2%) patients had at least one positive LN. The median RFS with at least one positive lymph node was 87.1 months (95% CI ≥ 14.3) when greater than 15 LNs were removed, compared to 16.9 months (95% CI, 13.6-35.6) and 17.3 months (95% CI, 8.5-39.8) when 5-15 and less than 5 LNs were removed, respectively (p = 0.02). In the cohort of 570 patients, there were 167 disease recurrences with location described on imaging, 98 (58.7%) had a NR and 69 (41.3%) recurred at other sites. Multivariable modeling identified that only positive LNs at surgical staging predicted NR (HR 3.8, 95% CI 1.4-10.2). CONCLUSION: In high-grade endometrial cancer, positive LNs predict NR, and RFS is longer with a more extensive LN dissection in women with positive LNs. Future prospective studies should evaluate the oncologic benefit of surgical removal of metastatic LNs in high-grade endometrial cancer.


Asunto(s)
Neoplasias Endometriales , Recurrencia Local de Neoplasia , Neoplasias Endometriales/patología , Neoplasias Endometriales/cirugía , Femenino , Humanos , Escisión del Ganglio Linfático/métodos , Ganglios Linfáticos/patología , Ganglios Linfáticos/cirugía , Metástasis Linfática/patología , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Estudios Prospectivos
5.
J Small Anim Pract ; 61(4): 259-262, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29745421

RESUMEN

A 7-year-old domestic shorthair cat was evaluated for progressive paraparesis, inability to jump, a paralysed tail and inability to void the bladder. Neurologic examination was consistent with a L4-S3 localisation. Survey radiographs of the lumbar vertebral column revealed L4-L7 vertebral body remodelling. A pre-contrast T1-weighted hyperintense, diffusely enhancing intradural lesion extending from L4 to S1 vertebral bodies was detected by MRI. Large, mesenchymal, round-to-polygonal cells arranged in nests or sheets were found on histologic examination at post mortem. These cells were characterised by abundant intracytoplasmic PAS-positive, diastase-resistant granules and positive immunoexpression of vimentin, S-100, neuron-specific enolase and desmin. This is the first report of a spinal granular cell tumour in a cat.


Asunto(s)
Enfermedades de los Gatos , Tumor de Células Granulares/veterinaria , Animales , Gatos , Vértebras Lumbares , Imagen por Resonancia Magnética , Paraparesia/veterinaria , Radiografía
6.
Nature ; 575(7783): 459-463, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31748725

RESUMEN

Long-duration γ-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterized by an initial phase of bright and highly variable radiation in the kiloelectronvolt-to-megaelectronvolt band, which is probably produced within the jet and lasts from milliseconds to minutes, known as the prompt emission1,2. Subsequently, the interaction of the jet with the surrounding medium generates shock waves that are responsible for the afterglow emission, which lasts from days to months and occurs over a broad energy range from the radio to the gigaelectronvolt bands1-6. The afterglow emission is generally well explained as synchrotron radiation emitted by electrons accelerated by the external shock7-9. Recently, intense long-lasting emission between 0.2 and 1 teraelectronvolts was observed from GRB 190114C10,11. Here we report multi-frequency observations of GRB 190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from 5 × 10-6 to 1012 electronvolts. We find that the broadband spectral energy distribution is double-peaked, with the teraelectronvolt emission constituting a distinct spectral component with power comparable to the synchrotron component. This component is associated with the afterglow and is satisfactorily explained by inverse Compton up-scattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed teraelectronvolt component are typical for GRBs, supporting the possibility that inverse Compton emission is commonly produced in GRBs.

7.
Vet J ; 253: 105378, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31685133

RESUMEN

Epilepsy is the most common chronic neurological disorder in dogs. Approximately 20-30% of dogs do not achieve satisfactory seizure control with two or more anti-epileptic drugs at appropriate dosages. This condition, defined as refractory epilepsy, is a multifactorial condition involving both acquired and genetic factors. The P glycoprotein might play and important role in the pathophysiological mechanism and it is encoded by the ABCB1 gene. An association between a single nucleotide variation of the ABCB1 gene (c.-6-180T>G) and phenobarbital resistance has previously been reported in a Border collie population with idiopathic epilepsy. To date, the presence and relevance of this polymorphism has not been assessed in other breeds. A multicentre retrospective, case-control study was conducted to investigate associations between ABCB1 c.-6-180T>G, clinical variables, and refractoriness in a multi-breed population of dogs with refractory idiopathic epilepsy. A secondary aim was to evaluate the possible involvement of the ABCB1 c.-6-180T>G single nucleotide variation this population. Fifty-two refractory and 50 responsive dogs with idiopathic epilepsy were enrolled. Of these, 45 refractory and 50 responsive (control) dogs were genotyped. The G allele was found in several breeds, but there was no evidence of association with refractoriness (P=0.69). The uncertain role of the c.-6-180T>G variation was further suggested by an association between the T/T genotype with both refractoriness and responsiveness in different breeds. Furthermore, high seizure density (cluster seizure) was the main clinical risk factor for refractory idiopathic epilepsy (P=0.003).


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Enfermedades de los Perros/genética , Epilepsia Refractaria/veterinaria , Polimorfismo de Nucleótido Simple , Animales , Estudios de Casos y Controles , Estudios de Cohortes , Perros , Epilepsia Refractaria/genética , Femenino , Italia , Masculino , Linaje , Estudios Retrospectivos , Factores de Riesgo
8.
Nat Commun ; 10(1): 1840, 2019 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-30992451

RESUMEN

Michael W. Sereda was incorrectly associated with the Department of Cellular Neurophysiology, Hanover Medical School, Carl-Neuberg-Str. 1, 30625 Hanover, Germany. The correct affiliations for Michael W. Sereda are Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany and Department of Clinical Neurophysiology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany.

9.
Nat Commun ; 10(1): 1467, 2019 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-30931926

RESUMEN

In contrast to acute peripheral nerve injury, the molecular response of Schwann cells in chronic neuropathies remains poorly understood. Onion bulb structures are a pathological hallmark of demyelinating neuropathies, but the nature of these formations is unknown. Here, we show that Schwann cells induce the expression of Neuregulin-1 type I (NRG1-I), a paracrine growth factor, in various chronic demyelinating diseases. Genetic disruption of Schwann cell-derived NRG1 signalling in a mouse model of Charcot-Marie-Tooth Disease 1A (CMT1A), suppresses hypermyelination and the formation of onion bulbs. Transgenic overexpression of NRG1-I in Schwann cells on a wildtype background is sufficient to mediate an interaction between Schwann cells via an ErbB2 receptor-MEK/ERK signaling axis, which causes onion bulb formations and results in a peripheral neuropathy reminiscent of CMT1A. We suggest that diseased Schwann cells mount a regeneration program that is beneficial in acute nerve injury, but that overstimulation of Schwann cells in chronic neuropathies is detrimental.


Asunto(s)
Enfermedades Desmielinizantes/genética , Neurregulina-1/genética , Comunicación Paracrina , Células de Schwann/metabolismo , Nervio Sural/metabolismo , Animales , Animales Modificados Genéticamente , Enfermedad de Charcot-Marie-Tooth/genética , Enfermedad de Charcot-Marie-Tooth/metabolismo , Enfermedad de Charcot-Marie-Tooth/patología , Enfermedades Desmielinizantes/metabolismo , Enfermedades Desmielinizantes/patología , Diabetes Mellitus Tipo 1/complicaciones , Neuropatías Diabéticas/etiología , Neuropatías Diabéticas/genética , Neuropatías Diabéticas/metabolismo , Neuropatías Diabéticas/patología , Humanos , Sistema de Señalización de MAP Quinasas , Ratones , Ratones Transgénicos , Microscopía Electrónica , Actividad Motora , Proteínas de la Mielina/genética , Neurregulina-1/metabolismo , Neuritis Autoinmune Experimental/genética , Neuritis Autoinmune Experimental/metabolismo , Neuritis Autoinmune Experimental/patología , Neuroglía/metabolismo , Ratas , Receptor ErbB-2/metabolismo , Células de Schwann/ultraestructura , Nervio Ciático/lesiones , Transducción de Señal , Nervio Sural/ultraestructura , Nervio Tibial
10.
Phys Rev Lett ; 122(5): 054802, 2019 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-30822008

RESUMEN

We give direct experimental evidence for the observation of the full transverse self-modulation of a long, relativistic proton bunch propagating through a dense plasma. The bunch exits the plasma with a periodic density modulation resulting from radial wakefield effects. We show that the modulation is seeded by a relativistic ionization front created using an intense laser pulse copropagating with the proton bunch. The modulation extends over the length of the proton bunch following the seed point. By varying the plasma density over one order of magnitude, we show that the modulation frequency scales with the expected dependence on the plasma density, i.e., it is equal to the plasma frequency, as expected from theory.

11.
Phys Rev Lett ; 122(5): 054801, 2019 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-30822039

RESUMEN

We measure the effects of transverse wakefields driven by a relativistic proton bunch in plasma with densities of 2.1×10^{14} and 7.7×10^{14} electrons/cm^{3}. We show that these wakefields periodically defocus the proton bunch itself, consistently with the development of the seeded self-modulation process. We show that the defocusing increases both along the bunch and along the plasma by using time resolved and time-integrated measurements of the proton bunch transverse distribution. We evaluate the transverse wakefield amplitudes and show that they exceed their seed value (<15 MV/m) and reach over 300 MV/m. All these results confirm the development of the seeded self-modulation process, a necessary condition for external injection of low energy and acceleration of electrons to multi-GeV energy levels.

12.
Science ; 363(6430): 968-971, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30792360

RESUMEN

The binary neutron star merger event GW170817 was detected through both electromagnetic radiation and gravitational waves. Its afterglow emission may have been produced by either a narrow relativistic jet or an isotropic outflow. High-spatial-resolution measurements of the source size and displacement can discriminate between these scenarios. We present very-long-baseline interferometry observations, performed 207.4 days after the merger by using a global network of 32 radio telescopes. The apparent source size is constrained to be smaller than 2.5 milli-arc seconds at the 90% confidence level. This excludes the isotropic outflow scenario, which would have produced a larger apparent size, indicating that GW170817 produced a structured relativistic jet. Our rate calculations show that at least 10% of neutron star mergers produce such a jet.

13.
Nature ; 561(7723): 363-367, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30188496

RESUMEN

High-energy particle accelerators have been crucial in providing a deeper understanding of fundamental particles and the forces that govern their interactions. To increase the energy of the particles or to reduce the size of the accelerator, new acceleration schemes need to be developed. Plasma wakefield acceleration1-5, in which the electrons in a plasma are excited, leading to strong electric fields (so called 'wakefields'), is one such promising acceleration technique. Experiments have shown that an intense laser pulse6-9 or electron bunch10,11 traversing a plasma can drive electric fields of tens of gigavolts per metre and above-well beyond those achieved in conventional radio-frequency accelerators (about 0.1 gigavolt per metre). However, the low stored energy of laser pulses and electron bunches means that multiple acceleration stages are needed to reach very high particle energies5,12. The use of proton bunches is compelling because they have the potential to drive wakefields and to accelerate electrons to high energy in a single acceleration stage13. Long, thin proton bunches can be used because they undergo a process called self-modulation14-16, a particle-plasma interaction that splits the bunch longitudinally into a series of high-density microbunches, which then act resonantly to create large wakefields. The Advanced Wakefield (AWAKE) experiment at CERN17-19 uses high-intensity proton bunches-in which each proton has an energy of 400 gigaelectronvolts, resulting in a total bunch energy of 19 kilojoules-to drive a wakefield in a ten-metre-long plasma. Electron bunches are then injected into this wakefield. Here we present measurements of electrons accelerated up to two gigaelectronvolts at the AWAKE experiment, in a demonstration of proton-driven plasma wakefield acceleration. Measurements were conducted under various plasma conditions and the acceleration was found to be consistent and reliable. The potential for this scheme to produce very high-energy electron bunches in a single accelerating stage20 means that our results are an important step towards the development of future high-energy particle accelerators21,22.

14.
Nature ; 551(7678): 67-70, 2017 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-29094694

RESUMEN

The merger of two neutron stars is predicted to give rise to three major detectable phenomena: a short burst of γ-rays, a gravitational-wave signal, and a transient optical-near-infrared source powered by the synthesis of large amounts of very heavy elements via rapid neutron capture (the r-process). Such transients, named 'macronovae' or 'kilonovae', are believed to be centres of production of rare elements such as gold and platinum. The most compelling evidence so far for a kilonova was a very faint near-infrared rebrightening in the afterglow of a short γ-ray burst at redshift z = 0.356, although findings indicating bluer events have been reported. Here we report the spectral identification and describe the physical properties of a bright kilonova associated with the gravitational-wave source GW170817 and γ-ray burst GRB 170817A associated with a galaxy at a distance of 40 megaparsecs from Earth. Using a series of spectra from ground-based observatories covering the wavelength range from the ultraviolet to the near-infrared, we find that the kilonova is characterized by rapidly expanding ejecta with spectral features similar to those predicted by current models. The ejecta is optically thick early on, with a velocity of about 0.2 times light speed, and reaches a radius of about 50 astronomical units in only 1.5 days. As the ejecta expands, broad absorption-like lines appear on the spectral continuum, indicating atomic species produced by nucleosynthesis that occurs in the post-merger fast-moving dynamical ejecta and in two slower (0.05 times light speed) wind regions. Comparison with spectral models suggests that the merger ejected 0.03 to 0.05 solar masses of material, including high-opacity lanthanides.

15.
Eur J Cancer ; 84: 114-120, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28802188

RESUMEN

BACKGROUND: Whether BRCA1 and BRCA2 mutation carriers have a clinically relevant elevated risk of uterine cancer has implications for risk-reducing surgery. AIM: This multicentre, prospective cohort study assessed uterine cancer risk for mutation carriers compared with the general population. METHODS: Eligible mutation carriers were enrolled in the Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer (kConFab) cohort study, had a uterus present and no history of uterine cancer at cohort entry. Epidemiological, lifestyle and clinical data were collected at cohort entry and updated three-yearly. Cancer events were verified using pathology reports. Follow-up was censored at death or last contact. Relative risk of uterine cancer was estimated using the standardised incidence ratio (SIR), with the expected number of cases determined using population-based data for Australia. RESULTS: Of 1,111 mutation carriers in kConFab, 283 were excluded due to prior hysterectomy (N = 278), prior uterine cancer (N = 2) or being non-residents (N = 3). After a median follow-up of 9.0 years, five incident uterine cancers were reported in the 828 eligible women (419 had prior breast cancer and 160 had prior tamoxifen use), compared to 2.04 expected (SIR = 2.45; 95% confidence interval [CI]: 0.80-5.72; P = 0.11). In 438 BRCA1 mutation carriers and 390 BRCA2 mutation carriers, three and two incident cases of uterine cancer were reported, respectively, compared to 1.04 expected (SIR = 2.87; 95% CI: 0.59-8.43; P = 0.18) and 0.99 expected (SIR = 2.01; 95% CI: 0.24-7.30; P = 0.52), respectively. All cases were endometrioid subtype, International Federation of Gynaecology and Obstetrics stage I-II disease. No serous uterine cancers were reported. CONCLUSIONS: Our findings are consistent with those from most other reports and do not support routine risk-reducing hysterectomy for BRCA1 and BRCA2 mutation carriers.


Asunto(s)
Proteína BRCA1/genética , Proteína BRCA2/genética , Biomarcadores de Tumor/genética , Heterocigoto , Mutación , Neoplasias Uterinas/genética , Adulto , Australia/epidemiología , Análisis Mutacional de ADN , Femenino , Predisposición Genética a la Enfermedad , Humanos , Histerectomía , Incidencia , Persona de Mediana Edad , Nueva Zelanda/epidemiología , Fenotipo , Estudios Prospectivos , Factores Protectores , Medición de Riesgo , Factores de Riesgo , Conducta de Reducción del Riesgo , Factores de Tiempo , Neoplasias Uterinas/diagnóstico , Neoplasias Uterinas/epidemiología , Neoplasias Uterinas/prevención & control
16.
Phys Med ; 39: 147-155, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28687192

RESUMEN

PURPOSE: In Selective Internal Radiation Therapy (SIRT), 99mTc-MAA SPECT images are commonly used to predict microspheres distribution but recent works used 90Y-microspheres PET images. Nevertheless, evaluation of the predictive power of 99mTc-MAA has been hampered by the lack of reliable comparisons between 99mTc-SPECT and 90Y-PET images. Our aim was to determine the "in situ" optimisation procedure in order to reliably compare 99mTc-SPECT and 90Y-PET images and achieve optimal personal dosimetry. METHODS: We acquired 99mTc-SPECT/CT and 90Y-PET/CT images of NEMA and Jaszczak phantoms. We found the best reconstruction parameters for quantification and for volume estimations. We determined adaptive threshold curves on the volumetric reconstruction. We copied the optimised volumes on the quantitative reconstruction, named here the "cross volumes" technique. Finally, we compared 99mTc-SPECT and 90Y-PET Dose Volume Histograms. RESULTS: Our "in situ" optimisation procedure decreased errors on volumes and quantification (from -44.2% and -15.8% to -3.4% and -3.28%, respectively, for the 26.5mL PET phantom sphere). Moreover, 99mTc-SPECT and 90Y-PET DVHs were equivalent only after the optimisation procedure (difference in mean dose <5% for the three biggest spheres). CONCLUSIONS: This work showed that a preliminary "in situ" phantom study was necessary to optimise volumes and quantification of 99mTc-SPECT and 90Y-PET images and allowed to achieve a reliable comparison between patient treatment planning and post implant dosimetry, notably by the use of the "cross volumes" technique. Methodology developed in this work will enable robust evaluations of the predictive power of 99mTc-SPECT, as well as dose-response relationship and side effects in SIRT treatments.


Asunto(s)
Tomografía Computarizada por Tomografía de Emisión de Positrones , Planificación de la Radioterapia Asistida por Computador , Tomografía Computarizada de Emisión de Fotón Único , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/radioterapia , Microesferas , Agregado de Albúmina Marcado con Tecnecio Tc 99m , Radioisótopos de Itrio
17.
J Biomed Mater Res A ; 105(8): 2228-2240, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28426158

RESUMEN

Autografts represent the gold standard for peripheral nerve reconstruction but their limited availability, the discrepancy of nerve caliber, and long surgical times are drawbacks. Allografts have therefore become a valid alternative option. In particular, acellular nerve allografts (ANAs) rather than fresh allografts do not need immunosuppression and appear to be safe and effective based on recent studies. An innovative method was conceived to obtain ANAs, so as to speed up nerve decellularization, without compromising nerve architecture, and without breaking the asepsis chain. Several detergent-based techniques, integrated with sonication and mechanical stirring, were tested in vitro on rabbit nerves, to identify, by microscopy and immunohistochemistry, the most effective protocol in terms of cell lysis and cellular debris clearance, while maintaining nerve architecture. Furthermore, a pilot in vivo study was performed: ANAs were implanted into tibial nerve defects of three rabbits, and autografts, representing the gold standard, in other three animals. Twelve weeks postoperatively, rabbits were clinically evaluated and euthanasized; grafts were harvested and microscopically and histomorphometrically analyzed. The method proved to be effective in vitro: the treatment removed axons, myelin and cells, without altering nerve architecture. The in vivo study did not reveal any adverse effect: animals maintained normal weight and function of posterior limb during the entire experimental time. A mild fibrotic reaction was observed, macrophages and leukocytes were rare or absent; ANAs regenerated fascicles and bundles were comparable versus autografts. Based on these results, this decellularization protocol is encouraging and deserves deeper investigations with further preclinical and clinical studies. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2228-2240, 2017.


Asunto(s)
Regeneración Tisular Dirigida/métodos , Regeneración Nerviosa , Nervios Periféricos/citología , Nervios Periféricos/trasplante , Andamios del Tejido , Aloinjertos , Animales , Detergentes/química , Masculino , Nervios Periféricos/fisiología , Nervios Periféricos/cirugía , Conejos , Sonicación/métodos , Andamios del Tejido/química , Trasplante Homólogo/métodos
18.
J Vet Intern Med ; 31(2): 498-504, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28144987

RESUMEN

BACKGROUND: Ascending/descending myelomalacia (ADMM) is a severe complication of thoracolumbar intervertebral disk herniation (TL-IVDH) in dogs. HYPOTHESIS/OBJECTIVES: To investigate the prevalence and risk factors for ADMM in nonambulatory dogs with surgically treated TL-IVDH. ANIMALS: Six-hundred and fifty-two client-owned dogs evaluated for TL-IVDH that underwent decompressive spinal surgery. METHODS: Retrospective medical record review from February 2007 through December 2015. RESULTS: Thirteen dogs developed ADMM, with an overall prevalence of 2.0%. The prevalence of ADMM was 0% in dogs with neurological signs graded 1 or 2 at admission or before magnetic resonance imaging (MRI) or surgical procedures, 0.6% in dogs with neurological signs graded 3, 2.7% in dogs with neurological signs graded 4, and 14.5% in dogs with neurological signs graded 5. Age (<5.8 years), neurological status (grade 5), site of disk herniation (L5-L6), duration of clinical signs before becoming nonambulatory (<24 hours), detection of intramedullary T2-weighted (T2W) hyperintensity, and a T2 length ratio >4.57 were significant risk factors in the univariate analysis for development of ADMM. CONCLUSIONS AND CLINICAL IMPORTANCE: The factors identified in this study may be useful for the prediction of ADMM. Multicenter studies with a higher number of dogs with ADMM are required to confirm these data.


Asunto(s)
Enfermedades de los Perros/epidemiología , Desplazamiento del Disco Intervertebral/veterinaria , Enfermedades de la Médula Espinal/veterinaria , Traumatismos de la Médula Espinal/veterinaria , Médula Espinal/patología , Animales , Enfermedades de los Perros/patología , Enfermedades de los Perros/cirugía , Perros , Femenino , Disco Intervertebral/lesiones , Disco Intervertebral/cirugía , Desplazamiento del Disco Intervertebral/complicaciones , Desplazamiento del Disco Intervertebral/epidemiología , Desplazamiento del Disco Intervertebral/cirugía , Masculino , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Enfermedades de la Médula Espinal/epidemiología , Enfermedades de la Médula Espinal/patología , Enfermedades de la Médula Espinal/cirugía , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/epidemiología , Traumatismos de la Médula Espinal/patología
20.
Sci Rep ; 6: 32602, 2016 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-27586846

RESUMEN

Purinergic signaling is involved in inflammation and cancer. Extracellular ATP accumulates in tumor interstitium, reaching hundreds micromolar concentrations, but its functional role on tumor vasculature and endothelium is unknown. Here we show that high ATP doses (>20 µM) strongly inhibit migration of endothelial cells from human breast carcinoma (BTEC), but not of normal human microvascular EC. Lower doses (1-10 µM result ineffective. The anti-migratory activity is associated with cytoskeleton remodeling and is significantly prevented by hypoxia. Pharmacological and molecular evidences suggest a major role for P2X7R and P2Y11R in ATP-mediated inhibition of TEC migration: selective activation of these purinergic receptors by BzATP mimics the anti-migratory effect of ATP, which is in turn impaired by their pharmacological or molecular silencing. Downstream pathway includes calcium-dependent Adenilyl Cyclase 10 (AC10) recruitment, cAMP release and EPAC-1 activation. Notably, high ATP enhances TEC-mediated attraction of human pericytes, leading to a decrease of endothelial permeability, a hallmark of vessel normalization. Finally, we provide the first evidence of in vivo P2X7R expression in blood vessels of murine and human breast carcinoma. In conclusion, we have identified a purinergic pathway selectively acting as an antiangiogenic and normalizing signal for human tumor-derived vascular endothelium.


Asunto(s)
Neoplasias de la Mama/patología , Movimiento Celular , AMP Cíclico/metabolismo , Células Endoteliales/patología , Receptores Purinérgicos P2X7/metabolismo , Receptores Purinérgicos P2/metabolismo , Transducción de Señal , Adenosina Trifosfato/farmacología , Animales , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Citoesqueleto/efectos de los fármacos , Citoesqueleto/metabolismo , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Femenino , Humanos , Ratones Endogámicos BALB C , Modelos Biológicos , Transducción de Señal/efectos de los fármacos
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