Cranial chordoma heterogeneity : Two case reports

Cordomas são neoplasias raras originadas da notocorda primitiva, que se localizam predominantemente em região sacroccígena e menos freqüentemente intracranianas, correspondendo de 3 a 5% dos tumores primários cerebrais. Os cordomas intracranianos são de manejo difícil, a ressecção cirúrgica geralmente é incompleta e os pacientes podem evoluir para óbito em decorrência do crescimento incontrolável do tumor e/ou compressão de estruturas nobres adjacentes. Neste trabalho os autores relatam dois pacientes com cordoma intracraniano cuja evolução clínica foi absolutamente distinta, dissertando sobre os diversos aspectos relacionados ao diagnóstico, tratamento e evolução dos dois casos.Chordomas are very rare primitive notochord-related tumors localized most frequently in sacrococcygeal and cranial regions. Intracranial lesions correspond to 3-5% of the primary tumors. Clinical management is very difficult; surgical ressection is usually incomplete, and can be associated with rapid tumor growth and multiple neurological involvement. In this study, the authors report on two cases of intracranial chordomas with diverse presentation and evolution, and discuss the diagnosis and the management of these patients

Cranial chordoma heterogeneity : Two case reports

Cordomas são neoplasias raras originadas da notocorda primitiva, que se localizam predominantemente em região sacroccígena e menos freqüentemente intracranianas, correspondendo de 3 a 5% dos tumores primários cerebrais. Os cordomas intracranianos são de manejo difícil, a ressecção cirúrgica geralmente é incompleta e os pacientes podem evoluir para óbito em decorrência do crescimento incontrolável do tumor e/ou compressão de estruturas nobres adjacentes. Neste trabalho os autores relatam dois pacientes com cordoma intracraniano cuja evolução clínica foi absolutamente distinta, dissertando sobre os diversos aspectos relacionados ao diagnóstico, tratamento e evolução dos dois casos.Chordomas are very rare primitive notochord-related tumors localized most frequently in sacrococcygeal and cranial regions. Intracranial lesions correspond to 3-5% of the primary tumors. Clinical management is very difficult; surgical ressection is usually incomplete, and can be associated with rapid tumor growth and multiple neurological involvement. In this study, the authors report on two cases of intracranial chordomas with diverse presentation and evolution, and discuss the diagnosis and the management of these patients

Estudo comparativo dos cariótipos na Síndrome de Turner : HCPA x literatura

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Electrocatalytic Reduction of Aldonic Acids to Aldoses on Gold Electrodes

Spent sulfite liquor, a side-stream from the pulp and paper industry, is an abundantly available carbon source for bio-based platform chemicals. The biotechnological valorization of side streams in biorefineries is hampered by the inability of many microorganisms to metabolize and deal with aldonic acids. Based on the principles of Green Chemistry, the electrochemical reduction of aldonic acids into the corresponding biomass sugars appears as a prospective process for the conversion of these acids into fermentable carbohydrates. In our paper, the investigation of electrochemical reduction of gluconic and xylonic acids into glucose and xylose, respectively, is presented. The proposed mechanism on a gold-coated silver electrode was determined via ReaxFF molecular dynamics simulations and quantum chemistry calculations. Model solutions with an aldonic acid concentration of 2.5 wt % were used for the experiments. Compared to a two-electrode compartment cell, the amounts of glucose and xylose produced in the undivided cell were more than 4 and 5.5 times higher, respectively. The electrode surface was analyzed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Despite the relatively low conversion rate, our results show that electrochemical reduction of aldonic acids into their corresponding aldoses in model solutions is possible, which represents an important step toward side-stream valorization