132 research outputs found

    Metástasis mandibular por carcinoma hepático: un infrecuente caso con severa hemorragia

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    El carcinoma hepatocelular (CH) es relativamente infrecuente en Europa y Estados Unidos, a pesar de que en este último país se diagnostican más de 13.000 nuevos casos cada año. Las metástasis mandibulares por CH son inusuales, recogiéndose en la literatura hasta el momento, 50 casos. En el presente trabajo se documenta un nuevo caso, correspondiente a un varón de 54 años que presentó una metástasis por HC en el cuerpo mandibular derecho, al año del tratamiento de su tumor primario. El curetaje-biopsia de la lesión se acompañó de una profusa hemorragia. El paciente falleció a los seis meses de la biopsia, con múltiples metástasis. Se describen las posibles vías de diseminación hematógena de la enfermedad.Hepatocellular carcinoma (HCC) is quite uncommon in Europe and USA, although in this last country more than 13,000 new cases are diagnosed every year. Mandibular metastases are unusual, with only 50 cases documented. In this article, we present a 54 year-old male patient with a metastasis of HCC in right mandibular body, one year after treating the primary tumor. Curettage and biopsy of the lesion was performed, followed by a profuse hemorrhage. The patient expired six months after the biopsy, with multiple metastases. We describe the different paths for hematogenic dissemination of the process

    in vivo toxicity of the ribosome-inactivating lectin ebulin f in elderly mice

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    Producción CientíficaEbulin f is a ribosome-inactivating protein (RIP) present in green fruits of the dwarf elder (Sambucus ebulus L). Since dwarf elder fruits are used for food and as a medicine, we assessed the study of toxicological effects and safety of ebulin f in elderly mice, comparing these results with those reported in young animals and with other RIPs. Female Swiss mice aged 6 and 12 months of age were intraperitoneally injected with a single dose from 1.4 to 4.5 mg/kg ebulin f. Heart, stomach, intestines, lung, kidney, liver, spleen, pancreas, adrenal gland, uterus, ovary and brain were studied. Histology analysis was carried out by staining with hematoxylin and eosin and Masson's trichrome observed with a light microscope, or apoptosis detection by TUNEL method observed with a confocal laser microscope. Treated animals injected with the lower dose could recover their weights, but after 14 days half of them died. The higher dose caused a progressive loss of body weight leading to death. In the animals of the experimental groups it was found atrophy of Lieberkühn's crypts, pneumonia, nephronal degeneration, myocardial atrophy, centrolobular hepatic necrosis, splenic white pulp necrosis foci and increased rate of apoptosis in the intestines and liver, in which apoptoses were mainly located in the vicinity of the lobular central vein. We conclude that ebulin f affects vital organs in elderly mice.UVa-GIR Inmunotoxinas AntitumoralesUCM-CAM Research group 95024

    High-Pressure and High-Temperature Chemistry of Phosphorus and Nitrogen: Synthesis and Characterization of α- and γ-P3N5

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    The direct chemical reactivity between phosphorus and nitrogen was induced under high-pressure and high-temperature conditions (9.1 GPa and 2000-2500 K), generated by a laser-heated diamond anvil cell and studied by synchrotron X-ray diffraction, Raman spectroscopy, and DFT calculations. alpha-P3N5 and gamma-P3N5 were identified as reaction products. The structural parameters and vibrational frequencies of gamma-P3N5 were characterized as a function of pressure during room-temperature compression and decompression to ambient conditions, determining the equation of state of the material up to 32.6 GPa and providing insight about the lattice dynamics of the unit cell during compression, which essentially proceeds through the rotation of the PN5 square pyramids and the distortion of the PN4 tetrahedra. Although the identification of alpha-P3N5 demonstrates for the first time the direct synthesis of this compound from the elements, its detection in the outer regions of the laser-heated area suggests alpha-P3N5 as an intermediate step in the progressive nitridation of phosphorus toward the formation of gamma-P3N5 with increasing coordination number of P by N from 4 to 5. No evidence of a higher-pressure phase transition was observed, excluding the existence of predicted structures containing octahedrally hexacoordinated P atoms in the investigated pressure range

    Importancia de la embolización preoperatoria en el tratamiento del quiste óseo aneurismático: Presentación de un caso clínico

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    Se describe el tratamiento de un quiste óseo aneurismático localizado en el raquis dorsal, en un niño de 8 años de edad. El quiste óseo aneurismático es una lesión benigna y a menudo extremadamente vascular. En la columna puede causar extensa destrucción ósea y compromiso de las estructuras neurales. Se demuestra el valor de la embolización preoperatoria reduciendo la vascularización y permitiendo su extirpación quirúrgica total.I n this report, th e managemen t o f a n aneurysma l bon e cyst i n th e thoraci c spin e o f an 8 year s ol d bo y is described . Aneurysma l bon e is a histologicall y benig n lesio n tha t is ofte n extremel y vascular . I n th e spine , it ca n caus e extensiv e bon e destructio n an d compress neura l structures. Th e valu e o f preoperativ e embo - lizatio n t o reduc e vascularity , allowin g tota l excisio n is demonstrated

    Charge analysis in (RE)CrO4 scheelites by combined Raman spectroscopy and computer simulations

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    The quest for structure-property relationships in scheelite-type (RE)CrO4 compounds (where RE is a rare earth element) is a difficult task due to the number of exceptions found in RE empirical trends and the uncommon Cr(V) oxidation state. In this work, we experimentally and computationally analyse how the stretching vibrational frequencies ν1(Ag) and ν3(Eg) associated with the [CrO4] tetrahedral units evolve in the (RE)CrO4 crystal family (RE ¼ Nd, Gd, Dy, Ho, and Lu). Since previously reported Cr–O distances and volume changes along with the RE series are not sufficiently accurate to explain the monotonic decrease observed for the ν1(Ag) and ν3(Eg) frequencies, a deeper analysis was performed involving the well-known fact that the bond strength (force constant) decreases as the interatomic distance increases. Our results demonstrates that structural and spectroscopic parameters can be reconciled with classical solid state chemistry ideas when charge effects are considered. This analysis provides a new method for predicting chromium oxidation states from Raman spectroscopy that can be generalised to the study of other crystal families

    Arginine deprivation alters microglial polarity and synergizes with radiation to eradicate non-arginine-auxotrophic glioblastoma tumors

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    New approaches for the management of glioblastoma (GBM) are an urgent and unmet clinical need. Here, we illustrate that the efficacy of radiotherapy for GBM is strikingly potentiated by concomitant therapy with the arginine-depleting agent ADI-PEG20 in a non-arginine-auxotrophic cellular background (argininosuccinate synthetase 1 positive). Moreover, this combination led to durable and complete radiological and pathological response, with extended disease-free survival in an orthotopic immune-competent model of GBM, with no significant toxicity. ADI-PEG20 not only enhanced the cellular sensitivity of argininosuccinate synthetase 1–positive GBM to ionizing radiation by elevated production of nitric oxide (˙NO) and hence generation of cytotoxic peroxynitrites, but also promoted glioma-associated macrophage/microglial infiltration into tumors and turned their classical antiinflammatory (protumor) phenotype into a proinflammatory (antitumor) phenotype. Our results provide an effective, well-tolerated, and simple strategy to improve GBM treatment that merits consideration for early evaluation in clinical trials.Fondo de Desarrollo Regional (FEDER). Programa Operativo Epiro 2014-2020National Strategic Reference Frameworks de la Unión Europea. NSRF 2014-2020-5033092Ministerio de Ciencia, Innovación y Universidades de España y fondos FEDER. RTI2018-098645-B-100Consejería de Economía y Conocimiento de la Junta de Andalucía y fondos FEDER. P18- RT-1372Universidad de Sevilla. US-126480

    Highs and Lows of Bond Lengths: Is There Any Limit?

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    Two distinct points on the potential energy curve (PEC) of a pairwise interaction, the zero-energy crossing point and the point where the stretching force constant vanishes, allow us to anticipate the range of possible distances between two atoms in diatomic, molecular moieties and crystalline systems. We show that these bond-stability boundaries are unambiguously defined and correlate with topological descriptors of electron-density-based scalar fields, and can be calculated using generic PECs. Chemical databases and quantum-mechanical calculations are used to analyze a full set of diatomic bonds of atoms from the s-p main block. Emphasis is placed on the effect of substituents in C-C covalent bonds, concluding that distances shorter than 1.14 Å or longer than 2.0 Å are unlikely to be achieved, in agreement with ultra-high-pressure data and transition-state distances, respectively. Presumed exceptions are used to place our model in the correct framework and to formulate a conjecture for chained interactions, which offers an explanation for the multimodal histogram of O-H distances reported for hundreds of chemical systems

    A Chemical Pressure-Induced Phase Transition Controlled by Lone Electron Pair Activity

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    The chemical pressure approach offers a new paradigm for property control in functional materials. In this work, we disclose a correlation between the β → α pressureinduced phase transition in SnMoO4 and the substitution process of Mo6+ by W6+ in SnMo1−xWxO4 solid solutions (x = 0-1). Special attention is paid to discriminating the role of the lone pair Sn2+ cation from the structural distortive effect along the Mo/W substitution process, which is crucial to disentangle the driven force of the transition phase. Furthermore, the reverse α → β transition observed at high temperature in SnWO4 is rationalized on the same basis as a negative pressure effect associated with a decreasing of W6+ percentage in the solid solution. This work opens a versatile chemical approach in which the types of interactions along the formation of solid solutions are clearly differentiated and can also be used to tune their properties, providing opportunities for the development of new materials

    Pressure-Driven Metallization in Hafnium Diselenide

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    The quest for new transition metal dichalcogenides (TMDs) with outstanding electronic properties operating at ambient conditions draws us to investigate the 1T-HfSe2 polytype under hydrostatic pressure. Diamond anvil cell (DAC) devices coupled to in- situ synchrotron X-ray, Raman and optical (VIS-NIR) absorption experiments along with density functional theory (DFT) based calculations prove that: (i) bulk 1T-HfSe2 exhibits strong structural and vibrational anisotropies, being the interlayer direction especially sensitive to pressure changes, (ii) the indirect gap of 1T-HfSe2 trend to vanish by a -0.1 eV/GPa pressure rate, slightly faster than MoS2 or WS2, (iii) the onset of the metallic behavior appears at Pmet ~10 GPa, which is to date the lowest pressure among common TMDs, and finally (iv) the electronic transition is explained by the bulk modulus B0-Pmet correlation, along with the pressure coefficient of the band gap, in terms of the electronic overlap between chalcogenide p-type and metal d-type orbitals
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