Superficial siderosis of the central nervous system in a patient with asymptomatic sacral paraganglioma as source of chronic bleeding. / Siderosis superficial del sistema nervioso central en una paciente con paraganglioma sacro asintomático como fuente de sangrado crónico.

INTRODUCTION: Superficial siderosis of the central nervous system is an infrequent pathology secondary to chronic bleeding into the cerebrospinal fluid. Spinal tumors are infrequent cause of superficial siderosis being ependymoma the most common etiology. CASE REPORT: We report the case of a woman with sensorineural hearing loss and cerebellar ataxia, diagnosed of superficial siderosis on brain MRI. She had no previous history of axial back pain or radicular leg pain or bowel or bladder incontinence. On spine MRI an intradural lesion was found at the S1 level. No signs of intratumoral hemorrhage were observed on MRI gradient-echo images. At surgery, an intradural soft mass with signs of chronic bleeding was completely resected. Based on microscopic examination and immunohistochemistry of the specimen, a diagnosis of paraganglioma World Health Organization grade I was made. CONCLUSIONS: Since the only proven treatment able to prevent further deterioration from superficial siderosis is to stop chronic bleeding into subarachnoid space, is of paramount importance to establish an early diagnosis of the source of bleeding. Cases of unexplained superficial siderosis of central nervous system should include routine spinal MRI to rule out bleeding of spinal tumor even in asymptomatic patients. Due to severity of potential deterioration caused by superficial siderosis, any tumoral lesion observed on spinal MRI even without documented sings of bleeding should be considered for resection.

TITLE: Siderosis superficial del sistema nervioso central en una paciente con paraganglioma sacro asintomático como fuente de sangrado crónico.Introducción. La siderosis superficial del sistema nervioso central es una patología poco frecuente secundaria al sangrado crónico en el líquido cefalorraquídeo. Los tumores medulares son causa poco habitual de siderosis superficial, y el ependimoma es la etiología más común. Caso clínico. Mujer con pérdida auditiva neurosensorial y ataxia cerebelosa, diagnosticada de siderosis superficial en la resonancia magnética cerebral. No tenía antecedentes de dolor raquídeo axial, dolor radicular ni incontinencia esfinteriana. En la resonancia magnética de la columna se encontró una lesión intradural en S1. No se observaron signos de hemorragia intratumoral en las secuencias de resonancia magnética en eco de gradiente. En la cirugía, se apreció una masa blanda intradural con signos de sangrado crónico que se resecó. Basado en el examen microscópico e inmunohistoquímico de la muestra, se alcanzó el diagnóstico de paraganglioma de grado I de la Organización Mundial de la Salud. Conclusiones. Dado que el único tratamiento probado capaz de prevenir un mayor deterioro por la siderosis superficial es detener el sangrado crónico en el espacio subaracnoideo, es importante establecer un diagnóstico temprano de la fuente de sangrado. Los casos no justificados de siderosis superficial del sistema nervioso central deben incluir una resonancia magnética de la columna rutinaria para descartar el sangrado de un tumor medular, incluso en pacientes asintomáticos. Debido a la gravedad del deterioro potencial causado por la siderosis superficial, cualquier lesión tumoral observada en una resonancia magnética del raquis, incluso sin presentar signos de sangrado, debería ser objeto de indicación quirúrgica.

Bevacizumab dose adjustment to improve clinical outcomes of glioblastoma.

BACKGROUND: Glioblastoma (GBM) is one of the most aggressive and vascularized brain tumors in adults, with a median survival of 20.9 months. In newly diagnosed and recurrent GBM, bevacizumab demonstrated an increase in progression-free survival, but not in overall survival. METHODS: We conducted an in silico analysis of VEGF expression, in a cohort of 1082 glioma patients. Then, to determine whether appropriate bevacizumab dose adjustment could increase the anti-angiogenic response, we used in vitro and in vivo GBM models. Additionally, we analyzed VEGFA expression in tissue, serum, and plasma in a cohort of GBM patients before and during bevacizumab treatment. RESULTS: We identified that 20% of primary GBM did not express VEGFA suggesting that these patients would probably not respond to bevacizumab therapy as we proved in vitro and in vivo. We found that a specific dose of bevacizumab calculated based on VEGFA expression levels increases the response to treatment in cell culture and serum samples from mice bearing GBM tumors. Additionally, in a cohort of GBM patients, we observed a correlation of VEGFA levels in serum, but not in plasma, with bevacizumab treatment performance. CONCLUSIONS: Our data suggest that bevacizumab dose adjustment could improve clinical outcomes in Glioblastoma treatment.

Polyethylene glycol improves current methods for circulating extracellular vesicle-derived DNA isolation.

BACKGROUND: Extracellular vesicles (EVs) are small membrane-bound vesicles which play an important role in cell-to-cell communication. Their molecular cargo analysis is presented as a new source for biomarker detection, and it might provide an alternative to traditional solid biopsies. However, the most effective approach for EV isolation is not yet well established. RESULTS: Here, we study the efficiency of the most common EV isolation methods-ultracentrifugation, Polyethlyene glycol and two commercial kits, Exoquick® and PureExo®. We isolated circulating EVs from the bloodstream of healthy donors, characterized the size and yield of EVs and analyzed their protein profiles and concentration. Moreover, we have used for the first time Digital-PCR to identify and detect specific gDNA sequences, which has several implications for diagnostic and monitoring many types of diseases. CONCLUSIONS: Our findings present Polyethylene glycol precipitation as the most feasible and less cost-consuming EV isolation technique.

Adhesion modification of neural stem cells induced by nanoscale ripple patterns.

We have studied the influence of anisotropic nanopatterns (ripples) on the adhesion and morphology of mouse neural stem cells (C17.2) on glass substrates using cell viability assay, optical microscopy and atomic force microscopy. The ripples were produced by defocused ion beam sputtering with inert Ar ions, which physically remove atoms from the surface at the energy of 800 eV. The ripple periodicity (∼200 nm) is comparable to the thickness of the cytoplasmatic microspikes (filopodia) which link the stem cells to the substrate. All methods show that the cell adhesion is significantly lowered compared to the same type of cells on flat glass surfaces. Furthermore, the AFM analysis reveals that the filopodia tend to be trapped parallel or perpendicular to the ripples, which limits the spreading of the stem cell on the rippled substrate. This opens the perspective of controlling the micro-adhesion of stem cells and the orientation of their filopodia by tuning the anisotropic substrate morphology without chemical reactions occurring at the surface.

Supraorbital trans-eyebrow craniotomy and fluorescence-guided resection of fronto-basal high grade gliomas.

OBJECT: To determine the effectiveness of fluorescence-guided resection of fronto-basal high grade gliomas by using the supraorbital trans-eyebrow craniotomy. METHODS: We present a single-institution experience of 6 consecutive patients presenting high grade brain glioma located on the fronto-basal area that were operated through a supraorbital trans-eyebrow craniotomy. Previous to surgery all patients were administered 20mg/kg of 5 aminolevulic acid so microscopic fluorescence-guided resection could be accomplished. Tumors were located on gyrus rectus (3 patients), medial orbital gyrus (2 patients), and anterior orbital gyrus (1 patient). RESULTS: Despite the narrow surgical corridor, fluorescence was useful in all cases. Fluorescence-guided resection allowed inclusion into the margins of resection of areas previously considered as normal under white light. Complete resection was obtained in 5 patients. No neurological postoperative new deficit was observed in this series. All six cases corresponded to glioblastoma. Only one case of superficial infection with delayed wound healing was reported as complication. All patients expressed a high level of satisfaction related to cosmetic result. CONCLUSIONS: Fluorescence-guided resection of fronto-basal high grade gliomas can be successfully achieved through supraorbital trans-eyebrow craniotomy. Benefits of supraorbital craniotomy in the management of fronto-basal high grade gliomas as well as usefulness of fluorescence-guided resection through a very narrow corridor are exposed.

Caracterización molecular de células progenitoras del parénquima subcortical cerebral humano adulto / Molecular characterization of progenitor cells from subcortical parenchyma of adult human brain

Objetivo: Caracterizar los patrones de expresión de marcadores de indiferenciación y diferenciación y las alteraciones morfológicas de las células progenitoras procedentes de parénquima cerebral humano adulto a lo largo de los pases en cultivo, evaluando su potencial para ser empleadas como fuente de progenitores de oligodendrocitos. Materiales y Métodos: Las células progenitoras se aislaron a partir de dos muestras obtenidas de pacientes sometidos a exéresis temporal por epilepsia. Para comprobar la evolución de los niveles de expresión de marcadores moleculares de diferenciación e indiferenciación en dichas células, se procedió a la extracción de ARNm en cada pase y a su estudio mediante RT-PCR. Se llevó a cabo un análisis de su capacidad proliferativa mediante inmunocitoquímica y un estudio de la evolución morfológica mediante microscopía. Resultados: Las células mostraron capacidad proliferativa durante los primeros pases en cultivo. Además, detectamos la expresión de marcadores de indiferenciación y diferenciación temprana a oligodendrocitos. Conclusión: Las células progenitoras aisladas de parénquima subcortical de cerebro humano pueden ser susceptibles de diferenciación a oligodendrocitos maduros, aunque en protocolos de diferenciación sólo deberían utilizarse pases tempranos (AU)

Objetive: characterize the behavior of progenitor cells isolated from subcortical parenchyma of human brain in culture. We have analyzed the changes in expression patterns of differentiation/undifferentiation markers as well as cell morphology along the passages and evaluated the potential to be further used as oligodendrocyte progenitors source. Material and Methods: We isolated progenitor cells from two different samples of subcortical parenchyma human brain of patients suffering from epilepsy. Cells were kept in culture until they became quiescent/senescent. Every other passages RNAs were isolated and checked for the expression of differentiation and undifferentiation markers by using RT-PCR. Proliferation was also addressed by RT-PCR and immunocytochemistry. We carried out cell morphology studies on semithin and ultrathin sections of cells. Results: We observed decreasing proliferative capacity of both two cell lines which became quiescent/senescent around passages 8-10. We detected the expression of either undifferentiation or early neural and oligodendrocytes differentiation markers. Conclusions: As for the expression of molecular markers, progenitor cells isolated from subcortical parenchyma of human brain have the potential to differentiate into mature oligodendrocytes (AU)

p73 deficiency results in impaired self renewal and premature neuronal differentiation of mouse neural progenitors independently of p53.

The question of how neural progenitor cells maintain its self-renewal throughout life is a fundamental problem in cell biology with implications in cancer, aging and neurodegenerative diseases. In this work, we have analyzed the p73 function in embryonic neural progenitor cell biology using the neurosphere (NS)-assay and showed that p73-loss has a significant role in the maintenance of neurosphere-forming cells in the embryonic brain. A comparative study of NS from Trp73-/-, p53KO, p53KO;Trp73-/- and their wild-type counterparts demonstrated that p73 deficiency results in two independent, but related, phenotypes: a smaller NS size (related to the proliferation and survival of the neural-progenitors) and a decreased capacity to form NS (self-renewal). The former seems to be the result of p53 compensatory activity, whereas the latter is p53 independent. We also demonstrate that p73 deficiency increases the population of neuronal progenitors ready to differentiate into neurons at the expense of depleting the pool of undifferentiated neurosphere-forming cells. Analysis of the neurogenic niches demonstrated that p73-loss depletes the number of neural-progenitor cells, rendering deficient niches in the adult mice. Altogether, our study identifies TP73 as a positive regulator of self-renewal with a role in the maintenance of the neurogenic capacity. Thus, proposing p73 as an important player in the development of neurodegenerative diseases and a potential therapeutic target.

New PCR primers for the screening of NRPS and PKS-I systems in actinomycetes: detection and distribution of these biosynthetic gene sequences in major taxonomic groups.

Nonribosomal peptide synthetases (NRPS) and type I polyketide synthases (PKS-I) are biosynthetic systems involved in the synthesis of a large number of important biologically active compounds produced by microorganisms, among others by actinomycetes. In order to assess the occurrence of these biosynthetic systems in this metabolically active bacterial group, we designed new PCR primers targeted to specifically amplify NRPS and PKS-I gene sequences from actinomycetes. The sequence analysis of amplified products cloned from two model systems and used to validate these molecular tools has shown the extreme richness of NRPS or PKS-I-like sequences in the actinomycete genome. When these PCR primers were tested on a large collection of 210 reference strains encompassing all major families and genera in actinomycetes, we observed that the wide distribution of these genes in the well-known productive Streptomyces species is also extended to other minor lineages where in some cases very few bioactive compounds have been identified to date.