Search results for "Brain Neoplasm"
showing 10 items of 249 documents
Towards a glioma model for surgical technique evaluation in the rat.
2013
Evaluation of new surgical techniques in animal models is frequently challenging. This article describes the pitfalls, peculiarities and the final best applicable model for evaluating surgical techniques for glioma resection.The C6 glioma cell line and the Sprague-Dawley rat strain were selected. Fifty-thousand glioma cells were stereotactically transplanted in the left hemisphere of 137 male adult rats. Evaluation of solid tumour formation, tumour growth and scheduling of surgical resection was performed by MR scanning at 1, 2, and 4 weeks after transplantation and 3 and 6 months after tumour resection. Microsurgical tumour resection was performed with conventional techniques or with the w…
The role of computed tomography in the diagnosis of brain tumors in infants and children.
1978
CT has considerably facilitated the diagnosis of intracranial tumors, especially in infants and children. The authors review their experience with a series of 260 children with proven brain tumors. In most cases CT is so conclusive that other diagnostic techniques are no longer often needed. Pneumoencephalography in particular has largely been replaced by CT in recent years in the authors' departments, and the frequency of central ventriculography with contrast material has decreased substantially. Particular diagnostic difficulties with regard to tumors near to or within the caudal brain stem, some posterior fossa tumors, small vermian tumors, and tumors of the cerebral hemispheres are dis…
Diagnostic performance of whole brain volume perfusion CT in intra-axial brain tumors: preoperative classification accuracy and histopathologic corre…
2012
Abstract Background To evaluate the preoperative diagnostic power and classification accuracy of perfusion parameters derived from whole brain volume perfusion CT (VPCT) in patients with cerebral tumors. Methods Sixty-three patients (31 male, 32 female; mean age 55.6 ± 13.9 years), with MRI findings suspected of cerebral lesions, underwent VPCT. Two readers independently evaluated VPCT data. Volumes of interest (VOIs) were marked circumscript around the tumor according to maximum intensity projection volumes, and then mapped automatically onto the cerebral blood volume (CBV), flow (CBF) and permeability Ktrans perfusion datasets. A second VOI was placed in the contra lateral cortex, as cont…
Cognitive Reserve Proxies Do Not Differentially Account for Cognitive Performance in Patients with Focal Frontal and Non-Frontal Lesions
2020
AbstractObjective:Cognitive reserve (CR) suggests that premorbid efficacy, aptitude, and flexibility of cognitive processing can aid the brain’s ability to cope with change or damage. Our previous work has shown that age and literacy attainment predict the cognitive performance of frontal patients on frontal-executive tests. However, it remains unknown whether CR also predicts the cognitive performance of non-frontal patients.Method:We investigated the independent effect of a CR proxy, National Adult Reading Test (NART) IQ, as well as age and lesion group (frontal vs. non-frontal) on measures of executive function, intelligence, processing speed, and naming in 166 patients with focal, unila…
Apoptosis in malignant glioma cells triggered by the temozolomide-induced DNA lesion O6-methylguanine
2006
Methylating drugs such as temozolomide (TMZ) are widely used in the treatment of brain tumours (malignant gliomas). The mechanism of TMZ-induced glioma cell death is unknown. Here, we show that malignant glioma cells undergo apoptosis following treatment with the methylating agents N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and TMZ. Cell death determined by colony formation and apoptosis following methylation is greatly stimulated by p53. Transfection experiments with O(6)-methylguanine-DNA methyltransferase (MGMT) and depletion of MGMT by O(6)-benzylguanine showed that, in gliomas, the apoptotic signal originates from O(6)-methylguanine (O(6)MeG) and that repair of O(6)MeG by MGMT prevent…
Isolation of Abiotrophia adiacens from a brain abscess which developed in a patient after neurosurgery.
1999
ABSTRACT We report the case of a patient who developed a large brain abscess after neurosurgery. Cerebrospinal fluid from the abscess drainage yielded Abiotrophia adiacens -specific PCR products and microorganisms that were identified by conventional microbiological methods and by 16S ribosomal DNA analysis as Abiotrophia adiacens , which was formerly classified as a member of nutritionally variant streptococci.
Multicolor 3D Printing of Complex Intracranial Tumors in Neurosurgery.
2020
Three-dimensional (3D) printing technologies offer the possibility of visualizing patient-specific pathologies in a physical model of correct dimensions. The model can be used for planning and simulating critical steps of a surgical approach. Therefore, it is important that anatomical structures such as blood vessels inside a tumor can be printed to be colored not only on their surface, but throughout their whole volume. During simulation this allows for the removal of certain parts (e.g., with a high-speed drill) and revealing internally located structures of a different color. Thus, diagnostic information from various imaging modalities (e.g., CT, MRI) can be combined in a single compact …
Redistribution of aquaporin-4 in human glioblastoma correlates with loss of agrin immunoreactivity from brain capillary basal laminae
2003
Vasogenic edema is one of the most serious clinical problems in brain tumors and tightly connected to water shifts between the different fluid compartments in the brain. Aquaporin water channels have been recognized to have an important impact on the development of edematous swelling in the brain. Astrocytes, which are believed to induce or at least maintain the blood-brain barrier in the brain capillary endothelial cells, express the aquaporin isoform AQP4. Normally, AQP4 is highly concentrated in the glial membrane where astrocytes contact mesenchymal space, such as perivascular or brain superficial regions. Parenchymal membranes do not show any immunocytochemical AQP4-specific signal. We…
Multiproject–multicenter evaluation of automatic brain tumor classification by magnetic resonance spectroscopy
2008
[EN] Automatic brain tumor classification by MRS has been under development for more than a decade. Nonetheless, to our knowledge, there are no published evaluations of predictive models with unseen cases that are subsequently acquired in different centers. The multicenter eTUMOUR project (2004-2009), which builds upon previous expertise from the INTERPRET project (2000-2002) has allowed such an evaluation to take place. A total of 253 pairwise classifiers for glioblastoma, meningioma, metastasis, and low-grade glial diagnosis were inferred based on 211 SV short TE INTERPRET MR spectra obtained at 1.5 T (PRESS or STEAM, 20-32 ms) and automatically pre-processed. Afterwards, the classifiers …
Implications of irradiating the subventricular zone stem cell niche
2016
Radiation therapy is a standard treatment for brain tumor patients. However, it comes with side effects, such as neurological deficits. While likely multi-factorial, the effect may in part be associated with the impact of radiation on the neurogenic niches. In the adult mammalian brain, the neurogenic niches are localized in the subventricular zone (SVZ) of the lateral ventricles and the dentate gyrus of the hippocampus, where the neural stem cells (NSCs) reside. Several reports showed that radiation produces a drastic decrease in the proliferative capacity of these regions, which is related to functional decline. In particular, radiation to the SVZ led to a reduced long-term olfactory memo…