Search results for "Brain Neoplasm"
showing 10 items of 249 documents
Incremental Gaussian Discriminant Analysis based on Graybill and Deal weighted combination of estimators for brain tumour diagnosis
2011
In the last decade, machine learning (ML) techniques have been used for developing classifiers for automatic brain tumour diagnosis. However, the development of these ML models rely on a unique training set and learning stops once this set has been processed. Training these classifiers requires a representative amount of data, but the gathering, preprocess, and validation of samples is expensive and time-consuming. Therefore, for a classical, non-incremental approach to ML, it is necessary to wait long enough to collect all the required data. In contrast, an incremental learning approach may allow us to build an initial classifier with a smaller number of samples and update it incrementally…
Regression of advanced rat and human gliomas by local or systemic treatment with oncolytic parvovirus H-1 in rat models
2010
Oncolytic virotherapy is a potential treatment modality under investigation for various malignancies including malignant brain tumors. Unlike some other natural or modified viruses that show oncolytic activity against cerebral neoplasms, the rodent parvovirus H-1 (H-1PV) is completely apathogenic in humans. H-1PV efficiently kills a number of tumor cells without harm to corresponding normal ones. In this study, the concept of H-1PV-based virotherapy of glioma was tested for rat (RG-2 cell-derived) and for human (U87 cell-derived) gliomas in immunocompetent and immunodeficient rat models, respectively. Large orthotopic rat and human glioma cell-derived tumors were treated with either single …
Magnetic Resonance Microscopy Contribution to Interpret High-Resolution Magic Angle Spinning Metabolomic Data of Human Tumor Tissue
2010
[EN] HRMAS NMR is considered a valuable technique to obtain detailed metabolic profile of unprocessed tissues. To properly interpret the HRMAS metabolomic results, detailed information of the actual state of the sample inside the rotor is needed. MRM (Magnetic Resonance Microscopy) was applied for obtaining structural and spatially localized metabolic information of the samples inside the HRMAS rotors. The tissue was observed stuck to the rotor wall under the effect of HRMAS spinning. MRM spectroscopy showed a transference of metabolites from the tissue to the medium. The sample shape and the metabolite transfer after HRMAS indicated that tissue had undergone alterations and it can not be s…
Selection of suitable housekeeping genes for expression analysis in glioblastoma using quantitative RT-PCR
2009
Abstract Background Considering the broad variation in the expression of housekeeping genes among tissues and experimental situations, studies using quantitative RT-PCR require strict definition of adequate endogenous controls. For glioblastoma, the most common type of tumor in the central nervous system, there was no previous report regarding this issue. Results Here we show that amongst seven frequently used housekeeping genes TBP and HPRT1 are adequate references for glioblastoma gene expression analysis. Evaluation of the expression levels of 12 target genes utilizing different endogenous controls revealed that the normalization method applied might introduce errors in the estimation of…
Identification of New Genetic Clusters in Glioblastoma Multiforme: EGFR Status and ADD3 Losses Influence Prognosis
2020
Glioblastoma multiforme (GB) is one of the most aggressive tumors. Despite continuous efforts to improve its clinical management, there is still no strategy to avoid a rapid and fatal outcome. EGFR amplification is the most characteristic alteration of these tumors. Although effective therapy against it has not yet been found in GB, it may be central to classifying patients. We investigated somatic-copy number alterations (SCNA) by multiplex ligation-dependent probe amplification in a series of 137 GB, together with the detection of EGFRvIII and FISH analysis for EGFR amplification. Publicly available data from 604 patients were used as a validation cohort. We found statistical associations…
A novel framework for MR image segmentation and quantification by using MedGA
2019
BACKGROUND AND OBJECTIVES: Image segmentation represents one of the most challenging issues in medical image analysis to distinguish among different adjacent tissues in a body part. In this context, appropriate image pre-processing tools can improve the result accuracy achieved by computer-assisted segmentation methods. Taking into consideration images with a bimodal intensity distribution, image binarization can be used to classify the input pictorial data into two classes, given a threshold intensity value. Unfortunately, adaptive thresholding techniques for two-class segmentation work properly only for images characterized by bimodal histograms. We aim at overcoming these limitations and…
Determination of metabolite concentrations in human brain tumour biopsy samples using HR-MAS and ERETIC measurements.
2009
Accurate determination of the concentration of the metabolites contained in intact human biopsies of 10 glioblastoma multiforme samples was achieved using one-dimensional 1H high-resolution magic angle spinning (HR-MAS) NMR combined with ERETIC™ (electronic reference to in vivo concentrations) measurements. The amount of sample used ranged from 6.8 to 12.9 mg. Metabolite concentrations were measured in each sample using two methods: with DSS (2,2-dimethyl-2-silapentane-5-sulfonate sodium salt) as an internal reference and with ERETIC™ as an external electronically generated reference. The ERETIC™ signal was shown to be highly reproducible and did not affect the spectral quality. The concent…
MRI abnormalities following repeated and incoming seizures.
2010
Abstract Neuroimaging, an important diagnostic tool frequently used in the evaluation of patients with epilepsy, has mainly the aim to identify structural abnormalities needing a treatment and to contribute to the definition of the aetiology. Brain magnetic resonance imaging (MRI) in epilepsy is more sensitive than computerized tomography (CT) scan for detecting abnormalities. Status epilepticus (SE) and repeated incoming seizures may determine extensive and transient or long lasting pronounced MRI changes. We describe a case of a 41-year-old woman with a history of brain neoplasm, whose contrast-enhanced MRI images following repeated and incoming seizures were characterized either by rever…
A smart and operator independent system to delineate tumours in Positron Emission Tomography scans
2018
Abstract Positron Emission Tomography (PET) imaging has an enormous potential to improve radiation therapy treatment planning offering complementary functional information with respect to other anatomical imaging approaches. The aim of this study is to develop an operator independent, reliable, and clinically feasible system for biological tumour volume delineation from PET images. Under this design hypothesis, we combine several known approaches in an original way to deploy a system with a high level of automation. The proposed system automatically identifies the optimal region of interest around the tumour and performs a slice-by-slice marching local active contour segmentation. It automa…
Three-dimensional invasion of human glioblastoma cells remains unchanged by X-ray and carbon ion irradiation in vitro.
2012
Purpose Cell invasion represents one of the major determinants that treatment has failed for patients suffering from glioblastoma. Contrary findings have been reported for cell migration upon exposure to ionizing radiation. Here, the migration and invasion capability of glioblastoma cells on and in collagen type I were evaluated upon irradiation with X-rays or carbon ions. Methods and Materials Migration on and invasion in collagen type I were evaluated in four established human glioblastoma cell lines exposed to either X-rays or carbon ions. Furthermore, clonogenic radiation survival, proliferation (5-bromo-2-deoxyuridine positivity), DNA double-strand breaks (γH2AX/53BP1-positive foci), a…