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1

Rest EEG Hidden Dynamics as a Discriminant for Brain Tumour Classification  

Microsoft Academic Search

\\u000a The hard problem of brain tumour detection is investigated based on rest EEG analysis, trying to ascertain whether the EEG\\u000a signal contains more hidden useful information than what is clinically employed. A nonlinear analysis of the hidden dynamics\\u000a is applied to the pair (F3, F4) of EEG leads - describing the electrical activity of the frontal part of the left

Rosaria Silipol; Gustavo Deco; Helmut Bartsch

2

Brain tumour stem cells  

Microsoft Academic Search

The dogma that the genesis of new cells is a negligible event in the adult mammalian brain has long influenced our perception and understanding of the origin and development of CNS tumours. The discovery that new neurons and glia are produced throughout life from neural stem cells provides new possibilities for the candidate cells of origin of CNS neoplasias. The

Rossella Galli; Brent A. Reynolds; Angelo L. Vescovi

2006-01-01

3

Targeted therapy for brain tumours  

Microsoft Academic Search

Although previously considered untreatable, brain tumours no longer carry the same prognosis as they did even a decade ago. Recent advances in drug delivery to the central nervous system have not only bypassed physiological constraints such as the blood–brain barrier, but have, in fact, changed the course of treatment for patients with malignant brain tumours. The creation of targeted therapies,

Maciej S. Lesniak; Henry Brem

2004-01-01

4

Angiogenesis in brain tumours  

Microsoft Academic Search

Despite aggressive surgery, radiotherapy and chemotherapy, malignant gliomas remain uniformly fatal. To progress, these tumours stimulate the formation of new blood vessels through processes driven primarily by vascular endothelial growth factor (VEGF). However, the resulting vessels are structurally and functionally abnormal, and contribute to a hostile microenvironment (low oxygen tension and high interstitial fluid pressure) that selects for a more

Emmanuelle di Tomaso; Dan G. Duda; Jay S. Loeffler; A. Gregory Sorensen; Tracy T. Batchelor; Rakesh K. Jain

2007-01-01

5

A second brain tumour and irradiation  

Microsoft Academic Search

Three patients are described in whom irradiation of 2750 rad or more was used in the management of primary brain tumours, and 21 years or more later a second brain tumour of a different type occurred. One of the new tumours was a meningioma and the other two were cerebral astrocytomas. There is evidence to show that moderate doses of

R G Robinson

1978-01-01

6

Why are brain tumours still being missed?  

Microsoft Academic Search

The prediagnosis period of 74 children with primary brain tumours was assessed to examine their presentation and reasons for any delay in diagnosis. Medical case notes were reviewed and parents were interviewed and asked to complete psychological questionnaires. Mean (SD) duration of clinical history was 20.0 (29.1) weeks. Most common symptoms were vomiting (65%) and headache (64%). Only 34% of

J Edgeworth; P Bullock; A Bailey; A Gallagher; M Crouchman

1996-01-01

7

Tomotherapy planning of small brain tumours  

Microsoft Academic Search

Helical tomotherapy (HT) combines a rotating intensity modulated fan beam with integrated CT imaging for high precision radiotherapy. HT plans for 12 patients with small brain tumours were compared with five other radiotherapy techniques. Proton techniques gave overall the best results, while HT was shown to produce better target dose uniformity (average SD=1.3%) and kept irradiation of organs at risk

Slav Yartsev; Tomas Kron; Luca Cozzi; Antonella Fogliata; Glenn Bauman

2005-01-01

8

Neuropsychological Differences between Survivors of Supratentorial and Infratentorial Brain Tumours  

ERIC Educational Resources Information Center

Background: The purpose of this study is to evaluate the relationship between brain tumour location and core areas of cognitive and behavioural functioning for paediatric brain tumour survivors. The extant literature both supports and refutes an association between paediatric brain tumour location and neurocognitive outcomes. We examined…

Patel, S. K.; Mullins, W. A.; O'Neil, S. H.; Wilson, K.

2011-01-01

9

Neuropsychological Differences between Survivors of Supratentorial and Infratentorial Brain Tumours  

ERIC Educational Resources Information Center

|Background: The purpose of this study is to evaluate the relationship between brain tumour location and core areas of cognitive and behavioural functioning for paediatric brain tumour survivors. The extant literature both supports and refutes an association between paediatric brain tumour location and neurocognitive outcomes. We examined…

Patel, S. K.; Mullins, W. A.; O'Neil, S. H.; Wilson, K.

2011-01-01

10

Neuropathology and prognosis of foetal brain tumours  

Microsoft Academic Search

A survey of brain tumours that had been diagnosed prenatally by foetal sonography yielded 89 cases. The most commonly found\\u000a tumour entities were teratomas (53.9%), glioblastomas (14.6%), lipomas (9.0%), plexus papillomas (7.9%) and craniopharyngiomas\\u000a (5.6%). The mean gestational age at ultrasound diagnosis was 30.0 weeks, ranging between 25.4 weeks in craniopharyngiomas\\u000a and 35.3 weeks in lipomas. Girls were more frequently

Christian H. Rickert

1999-01-01

11

Combined texture feature analysis of segmentation and classification of benign and malignant tumour CT slices.  

PubMed

A computer software system is designed for the segmentation and classification of benign from malignant tumour slices in brain computed tomography (CT) images. This paper presents a method to find and select both the dominant run length and co-occurrence texture features of region of interest (ROI) of the tumour region of each slice to be segmented by Fuzzy c means clustering (FCM) and evaluate the performance of support vector machine (SVM)-based classifiers in classifying benign and malignant tumour slices. Two hundred and six tumour confirmed CT slices are considered in this study. A total of 17 texture features are extracted by a feature extraction procedure, and six features are selected using Principal Component Analysis (PCA). This study constructed the SVM-based classifier with the selected features and by comparing the segmentation results with the experienced radiologist labelled ground truth (target). Quantitative analysis between ground truth and segmented tumour is presented in terms of segmentation accuracy, segmentation error and overlap similarity measures such as the Jaccard index. The classification performance of the SVM-based classifier with the same selected features is also evaluated using a 10-fold cross-validation method. The proposed system provides some newly found texture features have an important contribution in classifying benign and malignant tumour slices efficiently and accurately with less computational time. The experimental results showed that the proposed system is able to achieve the highest segmentation and classification accuracy effectiveness as measured by jaccard index and sensitivity and specificity. PMID:23094909

Padma, A; Sukanesh, R

2012-10-24

12

Neural stem cells, tumour stem cells and brain tumours: Dangerous relationships?  

Microsoft Academic Search

Neural stem cells (NSC) have been implicated not only in brain development and neurogenesis but also in tumourigenesis. Brain tumour stem cells (BTSC) have been isolated from several paediatric or adult human brain tumours, however their origin is still disputed. This review discusses the normal role of NSC in the adult mammalian brain and their anatomical location. It compares the

Reto Sutter; Gokhan Yadirgi; Silvia Marino

2007-01-01

13

Impact of brain tumour treatment on quality of life  

Microsoft Academic Search

Measurement of Health Related Quality of Life (HRQL) in brain tumour patients is important because brain tumours and brain\\u000a tumour treatment usually affect physical, cognitive as well as emotional functioning. Measurement of HRQL is important for\\u000a the understanding of disease burden and for the impact of specific tumour treatment. Quality of Life is a multidimensional\\u000a concept consisting of physical, psychological

Jan J. Heimans; Martin J. B. Taphoorn

2002-01-01

14

The effectiveness of neuroendoscopic interventions in children with brain tumours  

Microsoft Academic Search

Object: The purpose of this study was to review the efficacy of neuroendoscopic interventions in children with brain tumours and tumour-related hydrocephalus. Methods: In all, 61 consecutive neuroendoscopic operations carried out in 53 children with brain tumours over a 6-year period were reviewed. The patients ranged in age from 5 months to 18 years (median 9 years). Forty of 61

D. C. Macarthur; N. Buxton; M. Vloeberghs; J. Punt

2001-01-01

15

Automated EEG signal analysis for identification of epilepsy seizures and brain tumour.  

PubMed

Abstract Electroencephalography (EEG) is a clinical test which records neuro-electrical activities generated by brain structures. EEG test results used to monitor brain diseases such as epilepsy seizure, brain tumours, toxic encephalopathies infections and cerebrovascular disorders. Due to the extreme variation in the EEG morphologies, manual analysis of the EEG signal is laborious, time consuming and requires skilled interpreters, who by the nature of the task are prone to subjective judegment and error. Further, manual analysis of the EEG results often fails to detect and uncover subtle features. This paper proposes an automated EEG analysis method by combining digital signal processing and neural network techniques, which will remove error and subjectivity associated with manual analysis and identifies the existence of epilepsy seizure and brain tumour diseases. The system uses multi-wavelet transform for feature extraction in which an input EEG signal is decomposed in a sub-signal. Irregularities and unpredictable fluctuations present in the decomposed signal are measured using approximate entropy. A feed-forward neural network is used to classify the EEG signal as a normal, epilepsy or brain tumour signal. The proposed technique is implemented and tested on data of 500 EEG signals for each disease. Results are promising, with classification accuracy of 98% for normal, 93% for epilepsy and 87% for brain tumour. Along with classification, the paper also highlights the EEG abnormalities associated with brain tumour and epilepsy seizure. PMID:24116656

Sharanreddy, M; Kulkarni, P K

2013-10-14

16

Gamma knife radiosurgery for metastatic tumours in the brain stem  

Microsoft Academic Search

Background. Stereotactic radiosurgery has become important in the treatment of metastatic brain tumours and is often the first choice modality for eloquent or deep locations such as the brain stem. This study evaluated the efficacy of gamma knife radiosurgery (GKS) for the treatment of brain stem metastases. Method. The medical records of 25 patients with 31 tumours, 11 men and

T. Shuto; H. Fujino; H. Asada; S. Inomori; H. Nagano

2003-01-01

17

Cognitive deficits in adult patients with brain tumours  

Microsoft Academic Search

Cognitive function, with survival and response on brain imaging, is increasingly regarded as an important outcome measure in patients with brain tumours. This measure provides us with information on a patient's clinical situation and adverse treatment effects. Radiotherapy has been regarded as the main cause of cognitive decline in these patients, because children with brain tumours can develop intellectual deterioration

Martin JB Taphoorn; Martin Klein

2004-01-01

18

On the Implementation of HealthAgents : Agent-Based Brain Tumour Diagnosis  

Microsoft Academic Search

This paper introduces HealthAgents, an EC-funded research project to improve the classification of brain tumours through multi-agent\\u000a decision support over a secure and distributed network of local databases or Data Marts. HealthAgents will not only develop\\u000a new pattern recognition methods for distributed classification and analysis of in vivo MRS and ex vivo\\/in vitro HRMAS and\\u000a DNA data, but also define

Magí Lluch-Ariet; Francesc Estanyol; Mariola Mier; Carla Delgado; Horacio González-Vélez; Tiphaine Dalmas; Montserrat Robles; Carlos Sáez; Javier Vicente; Sabine Huffel; Jan Luts; Carles Arús; Ana Paula Candiota Silveira; Margarida Julià-Sapé; Andrew Peet; Alex Gibb; Yu Sun; Bernardo Celda; Maria Carmen Martínez Bisbal; Giulia Valsecchi; David Dupplaw; Bo Hu; Paul Lewis

19

Apoptosis in human primary brain tumours: actions of arachidonic acid  

Microsoft Academic Search

It has been postulated that loss of proliferative control in tumour cells is a consequence of depletion of cellular arachidonic acid (AA) and that exogenous AA and n-6 fatty acids may restore control of proliferation. To test this hypothesis and to investigate the activity of AA, apoptosis in human primary brain tumour cells was analysed using flow terminal deoxynucleotide transferase

J. R. Williams; H. A. Leaver; J. W. Ironside; E. P. Miller; I. R. Whittle; A. Gregor

1998-01-01

20

The new challenge of stem cell: Brain tumour therapy  

Microsoft Academic Search

The surprising similarity of much brain tumour behavior to the intrinsic properties of the neural stem\\/progenitor cell has triggered a recent interest in both arming stem cells to track and help eradicate tumours and in viewing stem cell biology as somehow integral to the emergence and\\/or production of the neoplasm itself. Moreover, based on the unique capacity of neural stem

F. Colleoni; Y. Torrente

2008-01-01

21

Association of brain tumours and arterial intracranial aneurysms  

Microsoft Academic Search

Summary A review of 116 cases of coexistent brain tumours and intracranial arterial aneurysms is made. The cases were collected from the literature, personal experience (8 cases) and different neurosurgical centres all over the world.

H. W. Pia; S. Obrador; J. G. Martin

1972-01-01

22

Progression from first symptom to diagnosis in childhood brain tumours  

Microsoft Academic Search

This study was undertaken to investigate the evolution of clinical features between onset of symptoms and diagnosis in children\\u000a with brain tumours and to identify ways of shortening the time to diagnosis. One hundred and thirty-nine children with a brain\\u000a tumour were recruited from four UK paediatric neuro-oncology centres. Children had a median of one symptom or sign at symptom

Sophie Wilne; Jacqueline Collier; Colin Kennedy; Anna Jenkins; Joanne Grout; Shona Mackie; Karin Koller; Richard Grundy; David Walker

23

Burnout in Mothers and Fathers of Children Surviving Brain Tumour  

Microsoft Academic Search

The aim of this paper was to investigate the occurrence of burnout among parents of brain tumour survivors. Burnout was assessed\\u000a in 24 mothers and 20 fathers of childhood brain tumour survivors, using the Shirom–Melamed Burnout Questionnaire. Parents\\u000a of children with no history of chronic or serious diseases served as a reference group. Mothers’ burnout scores were significantly\\u000a higher compared

Annika Lindahl Norberg

2007-01-01

24

Existential support in brain tumour patients and their spouses  

Microsoft Academic Search

Caring for patients with brain tumours raises existential questions. The aims of this study were to describe the opinions of nurses, patients and next-of-kin on existential support and how this is prioritised. Patients and method: a total of 20 brain tumour patients, 16 family members and 16 nurses underwent explorative, tape-recorded, semi-structured interviews about existential issues. Results: the nurses' opinions

Susan Strang; Peter Strang; Britt-Marie Ternestedt

2001-01-01

25

Spectral and lifetime domain measurements of rat brain tumours  

NASA Astrophysics Data System (ADS)

During glioblastoma surgery, delineation of the brain tumour margins remains difficult especially since infiltrated and normal tissues have the same visual appearance. This problematic constitutes our research interest. We developed a fibre-optical fluorescence probe for spectroscopic and time domain measurements. First measurements of endogenous tissue fluorescence were performed on fresh and fixed rat tumour brain slices. Spectral characteristics, fluorescence redox ratios and fluorescence lifetime measurements were analysed. Fluorescence information collected from both, lifetime and spectroscopic experiments, appeared promising for tumour tissue discrimination. Two photon measurements were performed on the same fixed tissue. Different wavelengths are used to acquire two-photon excitation-fluorescence of tumorous and healthy sites.

Abi Haidar, D.; Leh, B.; Allaoua, K.; Genoux, A.; Siebert, R.; Steffenhagen, M.; Peyrot, D.; Sandeau, N.; Vever-Bizet, C.; Bourg-Heckly, G.; Chebbi, I.; Collado-Hilly, M.

2012-02-01

26

Towards drug discovery for brain tumours: interaction of kinins and tumours at the blood brain barrier interface.  

PubMed

Cancers of the brain are intrinsically more complicated to treat than systemic malignancies due to the unique anatomical features of the brain. The blood-brain barrier prevents chemotherapeutic agents from reaching brain neoplasms, and angiogenesis occurs as the metabolic needs of the tumour increase, thus further complicating treatment. The newly formed blood vessels form the blood-tumour barrier and are distinct from the blood-brain barrier in that they are more permeable. Being more permeable, these abnormal blood vessels lead to the formation of peri-tumoural edema, which is the cause of much morbidity and mortality associated with central nervous system neoplasms. While the cause of the increased permeability is unclear, kinins have been implicated in regulating the permeability of normal vasculature. Kinins are also known to exert many inflammatory actions affecting both normal and angiogenic blood vessels, as well as tumour cells. The vasodilatory and vascular permeabilizing effects of kinins, and particularly bradykinin and substance P, have been investigated with regard to delivery of chemotherapeutic agents to neoplastic brain tissue through both vascular barriers. In contrast, kinin receptor antagonists have been found to exert effects on tumour cells that result in decreased angiogenesis, tumour cell motility and growth. Thus, many recent patents describe kinin activity on brain vasculature, which may play an integral role in the development of treatments for malignancies in the central nervous system through amelioration of angiogenesis. In conjunction, patents that discuss the ability of kinins to decrease tumour cell migration and proliferation demonstrate that kinins may offer novel approaches to brain tumour therapy in the future. PMID:21073431

Harford-Wright, Elizabeth; Lewis, Kate M; Vink, Robert

2011-01-01

27

Brain tumour stem cells: the undercurrents of human brain cancer and their relationship to neural stem cells  

Microsoft Academic Search

Conceptual and technical advances in neural stem cell biology are being applied to the study of human brain tumours. These studies suggest that human brain tumours are organized as a hierarchy and are maintained by a small number of tumour cells that have stem cell properties. Most of the bulk population of human brain tumours comprise cells that have lost

Peter B. Dirks

2008-01-01

28

Residential Radon and Brain Tumour Incidence in a Danish Cohort  

PubMed Central

Background Increased brain tumour incidence over recent decades may reflect improved diagnostic methods and clinical practice, but remain unexplained. Although estimated doses are low a relationship between radon and brain tumours may exist. Objective To investigate the long-term effect of exposure to residential radon on the risk of primary brain tumour in a prospective Danish cohort. Methods During 1993–1997 we recruited 57,053 persons. We followed each cohort member for cancer occurrence from enrolment until 31 December 2009, identifying 121 primary brain tumour cases. We traced residential addresses from 1 January 1971 until 31 December 2009 and calculated radon concentrations at each address using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate-ratios (IRR) and 95% confidence intervals (CI) for the risk of primary brain tumours associated with residential radon exposure with adjustment for age, sex, occupation, fruit and vegetable consumption and traffic-related air pollution. Effect modification by air pollution was assessed. Results Median estimated radon was 40.5 Bq/m3. The adjusted IRR for primary brain tumour associated with each 100 Bq/m3 increment in average residential radon levels was 1.96 (95% CI: 1.07; 3.58) and this was exposure-dependently higher over the four radon exposure quartiles. This association was not modified by air pollution. Conclusions We found significant associations and exposure-response patterns between long-term residential radon exposure radon in a general population and risk of primary brain tumours, adding new knowledge to this field. This finding could be chance and needs to be challenged in future studies.

Brauner, Elvira V.; Andersen, Zorana J.; Andersen, Claus E.; Pedersen, Camilla; Gravesen, Peter; Ulbak, Kaare; Hertel, Ole; Loft, Steffen; Raaschou-Nielsen, Ole

2013-01-01

29

[Radiotherapy for brain tumours: Which margins should we apply?].  

PubMed

Radiotherapy is a major modality in the treatment of brain tumours. The target volumes definition has to be precise for the radiation planification. The gross target volume (GTV) is most of the time delineated within the fusion of the planning CT scan with the appropriated MRI sequences. The clinical target volume (CTV) definition is more complex: it varies in time following the evolution of scientific knowledge and also depending of the school of thought. This article offers a review of the literature about the margins applied in brain tumours radiotherapy for gliomas (high grade, anaplastic, low grade and brain stem gliomas), embryologic tumours (medulloblastomas and primitive neuroectodermal tumours [PNET]), ependymomas, atypical teratoid rahbdoid tumours (ATRT), craniopharyngiomas, pineal gland tumours, primary central nervous cell lymphomas, meningiomas and schwannomas. New imaging modalities such as diffusion-weighted imaging, dynamic contrast enhanced, spectroscopic MRI and PET scan will allow us to delineate more precisely the target volumes and to realise dose-painting by adapting the dose to the tumour metabolism. PMID:24011792

Martin, V; Moyal, E; Delannes, M; Padovani, L; Sunyach, M-P; Feuvret, L; Dhermain, F; Noël, G; Laprie, A

2013-09-05

30

The 2007 WHO Classification of Tumours of the Central Nervous System  

Microsoft Academic Search

The fourth edition of the World Health Organization (WHO) classification of tumours of the central nervous system, published\\u000a in 2007, lists several new entities, including angiocentric glioma, papillary glioneuronal tumour, rosette-forming glioneuronal\\u000a tumour of the fourth ventricle, papillary tumour of the pineal region, pituicytoma and spindle cell oncocytoma of the adenohypophysis.\\u000a Histological variants were added if there was evidence of

David N. Louis; Hiroko Ohgaki; Otmar D. Wiestler; Webster K. Cavenee; Peter C. Burger; Anne Jouvet; Bernd W. Scheithauer; Paul Kleihues

2007-01-01

31

The origin of experimental brain tumours: A sequential study  

Microsoft Academic Search

Summary A sequential study of rat brains treated transplacentally with the neurotropic carcinogen ethylnitrosourea reveals small foci of cell proliferations from the age of 8 weeks. These lesions consist mainly of undifferentiated cells of the subependymal plate type. They occur in those areas in which gliomas develop and represent the earliest, histologically detectable, changes in the development of brain tumours.

P. L. Lantos; D. J. Cox

1976-01-01

32

Increased aquaporin 1 water channel expression inhuman brain tumours  

Microsoft Academic Search

Aquaporin 1 is a water channel protein. There was little aquaporin 1 immunoreactivity in normal brain parenchyma. In astrocytomas, aquaporin 1 was expressed in microvessel endothelia and neoplastic astrocytes. In metastatic carcinomas, aquaporin 1 was present in microvessel endothelia and reactive astrocytes. Aquaporin 1 may participate in the formation of brain tumour oedema.

S Saadoun; M C Papadopoulos; D C Davies; B A Bell; S Krishna

2002-01-01

33

Cancers in the first-degree relatives of children with brain tumours  

Microsoft Academic Search

We used the nationwide Swedish Family-Cancer Database with 2060 childhood brain tumours diagnosed in the period 1958–1996 to analyse the risk of this tumour by parental cancers and in siblings of childhood brain tumour probands. Groups of patients were compared by calculating standardized incidence ratios (SIRs) for brain tumours in offspring. 1.3% of brain tumour patients had a parent with

K Hemminki; X Li; P Vaittinen; C Dong; K Hemminki

2000-01-01

34

Cytokine Patterns in Brain Tumour Progression  

PubMed Central

Inflammation represents the immune system response to external or internal aggressors such as injury or infection in certain tissues. The body's response to cancer has many parallels with inflammation and repair; the inflammatory cells and cytokines present in tumours are more likely to contribute to tumour growth, progression, and immunosuppression, rather than in building an effective antitumour defence. Using new proteomic technology, we have investigated serum profile of pro- (IL-1?, IL-6, IL-8, IL-12, GM-CSF, and TNF-?) and anti-inflammatory cytokines (IL-4, IL-10), along with angiogenic factors (VEGF, bFGF) in order to assess tumoural aggressiveness. Our results indicate significant dysregulation in serum levels of cytokines and angiogenic factors, with over threefold upregulation of IL-6, IL-1?, TNF-?, and IL-10 and up to twofold upregulation of VEGF, FGF-2, IL-8, IL-2, and GM-CSF. These molecules are involved in tumour progression and aggressiveness, and are also involved in a generation of disease associated pain.

Albulescu, Radu; Codrici, Elena; Popescu, Ionela Daniela; Mihai, Simona; Necula, Laura Georgiana; Petrescu, Daniel; Teodoru, Mihaela; Tanase, Cristiana Pistol

2013-01-01

35

Recent advances in embryonal tumours of the central nervous system  

Microsoft Academic Search

Introduction: Embryonal tumours of the central nervous system (CNS) are the commonest malignant paediatric brain tumours. This group includes medulloblastomas, supraten- torial primitive neuroectodermal tumours, atypical teratoid\\/rhabdoid tumours, ependymoblastomas, and medulloepitheliomas. Earlier, all these tumours were grouped under a broad category of primitive neuroec- todermal tumours (PNETs). However, the current WHO classification (2000) separates them into individual types based on

Chitra Sarkar; Prabal Deb; Mehar Chand Sharma

2005-01-01

36

The candidate tumour suppressor protein ING4 regulates brain tumour growth and angiogenesis  

Microsoft Academic Search

Gliomas are the most common primary tumours of the central nervous system, with nearly 15,000 diagnosed annually in the United States and a lethality approaching 80% within the first year of glioblastoma diagnosis. The marked induction of angiogenesis in glioblastomas suggests that it is a necessary part of malignant progression; however, the precise molecular mechanisms underlying the regulation of brain

Igor Garkavtsev; Sergey V. Kozin; Olga Chernova; Lei Xu; Frank Winkler; Edward Brown; Gene H. Barnett; Rakesh K. Jain

2004-01-01

37

Growth impairment in children treated for brain tumours  

Microsoft Academic Search

Growth and growth hormone (GH) secretion were studied in 14 children with brain tumours before radiation and chemotherapy and at various time intervals afterwards. The peak GH response to hypoglycaemia was normal in all patients before radiation. In 6 patients the peak GH response was impaired 1 year after radiation, and in a seventh it was normal at 1 year

S M Shalet; C G Beardwell; B M Aarons; D Pearson; P H Jones

1978-01-01

38

Thyroid dysfunction after radiotherapy and chemotherapy of brain tumours  

Microsoft Academic Search

We investigated thyroid function in 119 survivors of treatment for brain tumours not involving the hypothalamo-pituitary region. Cranial irradiation did not effect thyroid function but 11 of 47 children (23%) who had spinal irradiation had raised concentrations of thyroid stimulating hormone. Chemotherapy further increased the incidence of thyroid dysfunction: two of four patients who had cranial irradiation and chemotherapy and

E A Livesey; C G Brook

1989-01-01

39

Computer and robotic assisted resection of brain tumours  

Microsoft Academic Search

Six children ages 2 to 10 years harbouring deep brain tumours were operated upon using a computer and robotic assisted system. A radical excision was achieved in all cases with no significant morbidity or any mortality. The system consists of an interactive 3 dimensional (3D) display of computed tomography image contours and digitized cerebral angiograms taken using the BRW stereotactic

James M. Drake; Michael Joy; Andrew Goldenberg; David Kreindler

1991-01-01

40

The role of cytogenetics in the classification of soft tissue tumours  

Microsoft Academic Search

Soft tissue tumours represent a heterogeneous group of mesenchymal lesions, and their classification is the subject of continuous\\u000a debate. Chromosome analysis, molecular cytogenetics and molecular assays may become increasingly useful in diagnosis, and\\u000a this review summarises advances in the cytogenetic characterisation and classification of soft tissue tumours. Among the group\\u000a of fibrous lesions, superficial fibromatosis exhibits trisomy 8. This genomic

A. P. Dei Tos; Paola Dal Cin

1997-01-01

41

Iodine-125 brachytherapy for brain tumours - a review  

PubMed Central

Iodine-125 brachytherapy has been applied to brain tumours since 1979. Even though the physical and biological characteristics make these implants particularly attractive for minimal invasive treatment, the place for stereotactic brachytherapy is still poorly defined. An extensive review of the literature has been performed, especially concerning indications, results and complications. Iodine-125 seeds have been implanted in astrocytomas I-III, glioblastomas, metastases and several other tumour entities. Outcome data given in the literature are summarized. Complications are rare in carefully selected patients. All in all, for highly selected patients with newly diagnosed or recurrent primary or metastatic tumours, this method provides encouraging survival rates with relatively low complication rates and a good quality of life.

2012-01-01

42

Primary pulmonary solitary fibrous tumour with brain metastases.  

PubMed

Solitary fibrous tumour (SFT) is a mesenchymal neoplasm of subendothelial origin that can be found in all anatomical locations, but rarely in the lungs. A 71-year old female was referred to our hospital because of the increase in size of a solitary pulmonary mass. Chest contrast-enhanced dynamic computed tomography showed a well-circumscribed lobulated mass measuring 3.1 × 1.6 cm in the posterior segment of the right upper lobe of the lung. Positron emission tomography with (18)F-fluorodeoxyglucose (FDG) demonstrated that the mass had high FDG uptake. A right upper lobectomy of the lung and mediastinal lymphadenectomy were performed. The tumour was pathologically diagnosed as an SFT. Seven months later, the patient was found to have brain metastases of the tumour, which led to dizziness. A craniotomy and successive radiosurgery with a gamma knife were performed for the metastatic tumours. She is still alive without evidence of disease 12 months after the treatment of the metastases. Pulmonary SFT seldom behaves aggressively, and only two previous cases of primary pulmonary SFT with brain metastases have been reported. Local therapy including surgery and radiotherapy against metastases from SFT could help improve the survival of such patients. PMID:23711464

Ozeki, Naoki; Kawaguchi, Koji; Taniguchi, Tetsuo; Yokoi, Kohei

2013-05-27

43

Clinical effect of interferon in malignant brain tumours  

Microsoft Academic Search

Summary Phase I and phase II clinical studies of interferon (IFN) were conducted in malignant brain tumours (47 cases of glioblastoma, medulloblastoma and others) using three preparations of the drug. The drug was administered daily in doses 3.0 - 9.0 × 106 I.U. locally or intravenously (ß-type) or intramuscularly (a-type). The administration was continued as many days as possible, eight

Masakatsu Nagai; Toshimoto Arai

1984-01-01

44

Photodynamic assisted surgical resection and treatment of malignant brain tumours technique, technology and clinical application  

Microsoft Academic Search

Malignant brain tumours have a dismal prognosis with current state of the art technology. The main reasons for this lost battle in the battlefield of cancer are tumour cell invisibility to the surgical microscope and brain invasion. However, the vast majority of these tumours relapse locally making local radical removal the main strategy in their successful eradication. PDD and PDT

M. Sam Eljamel

2004-01-01

45

Making sense of brain tumour: A qualitative investigation of personal and social processes of adjustment  

Microsoft Academic Search

This study investigated personal and social processes of adjustment at different stages of illness for individuals with brain tumour. A purposive sample of 18 participants with mixed tumour types (9 benign and 9 malignant) and 15 family caregivers was recruited from a neurosurgical practice and a brain tumour support service. In-depth semi-structured interviews focused on participants' perceptions of their adjustment,

Tamara Ownsworth; Suzanne Chambers; Anna Hawkes; David G. Walker; David Shum

2011-01-01

46

Mobile phones, cordless phones and the risk for brain tumours.  

PubMed

The Hardell-group conducted during 1997-2003 two case control studies on brain tumours including assessment of use of mobile phones and cordless phones. The questionnaire was answered by 905 (90%) cases with malignant brain tumours, 1,254 (88%) cases with benign tumours and 2,162 (89%) population-based controls. Cases were reported from the Swedish Cancer Registries. Anatomical area in the brain for the tumour was assessed and related to side of the head used for both types of wireless phones. In the current analysis we defined ipsilateral use (same side as the tumour) as >or=50% of the use and contralateral use (opposite side) as <50% of the calling time. We report now further results for use of mobile and cordless phones. Regarding astrocytoma we found highest risk for ipsilateral mobile phone use in the >10 year latency group, OR=3.3, 95% CI=2.0-5.4 and for cordless phone use OR=5.0, 95% CI=2.3-11. In total, the risk was highest for cases with first use <20 years age, for mobile phone OR=5.2, 95% CI=2.2-12 and for cordless phone OR=4.4, 95% CI=1.9-10. For acoustic neuroma, the highest OR was found for ipsilateral use and >10 year latency, for mobile phone OR=3.0, 95% CI=1.4-6.2 and cordless phone OR=2.3, 95% CI=0.6-8.8. Overall highest OR for mobile phone use was found in subjects with first use at age <20 years, OR=5.0, 95% CI 1.5-16 whereas no association was found for cordless phone in that group, but based on only one exposed case. The annual age-adjusted incidence of astrocytoma for the age group >19 years increased significantly by +2.16%, 95% CI +0.25 to +4.10 during 2000-2007 in Sweden in spite of seemingly underreporting of cases to the Swedish Cancer Registry. A decreasing incidence was found for acoustic neuroma during the same period. However, the medical diagnosis and treatment of this tumour type has changed during recent years and underreporting from a single center would have a large impact for such a rare tumour. PMID:19513546

Hardell, Lennart; Carlberg, Michael

2009-07-01

47

The diagnosis of brain tumours in children: a guideline to assist healthcare professionals in the assessment of children who may have a brain tumour  

Microsoft Academic Search

BackgroundBrain tumours are the commonest solid tumour in children. Children with brain tumours are frequently unwell for months prior to diagnosis. A prolonged period between symptom onset and diagnosis is associated with increased morbidity.ObjectiveTo develop an evidence-based clinical guideline to support healthcare professionals in the identification, assessment and investigation of children presenting with symptoms and signs that could be due

Sophie Wilne; Karin Koller; Jacqueline Collier; Colin Kennedy; Richard Grundy; David Walker

2010-01-01

48

Neuropsychometric evaluation of long-term survivors of adult brain tumours: relationship with tumour and treatment parameters  

Microsoft Academic Search

Background: Cognitive deficits are the hallmark of dose limiting late radiation morbidity in the CNS. Little is known about the neuropsychometric morbidity of treatment in adults with primary brain tumours. We set out to evaluate systematically the neuropsychometric function of all long-term survivors in order to document the frequency and severity of impairment and study its relationship with tumour and

A. Gregor; A. Cull; E. Traynor; M. Stewart; F. Lander; S. Love

1996-01-01

49

Functional MRI and intraoperative brain mapping to evaluate brain plasticity in patients with brain tumours and hemiparesis  

Microsoft Academic Search

OBJECTIVETo support the hypothesis about the potential compensatory role of ipsilateral corticofugal pathways when the contralateral pathways are impaired by brain tumours.METHODSRetrospective analysis was carried out on the results of functional MRI (fMRI) of a selected group of five paretic patients with Rolandic brain tumours who exhibited an abnormally high ipsilateral\\/contralateral ratio of activation—that is, movements of the paretic hand

F E Roux; K Boulanouar; D Ibarrola; M Tremoulet; F Chollet; I Berry

2000-01-01

50

Functional imaging in adult and paediatric brain tumours.  

PubMed

Imaging is a key component in the management of brain tumours, with MRI being the preferred modality for most clinical scenarios. However, although conventional MRI provides mainly structural information, such as tumour size and location, it leaves many important clinical questions, such as tumour type, aggressiveness and prognosis, unanswered. An increasing number of studies have shown that additional information can be obtained using functional imaging methods (which probe tissue properties), and that these techniques can give key information of clinical importance. These techniques include diffusion imaging, which can assess tissue structure, and perfusion imaging and magnetic resonance spectroscopy, which measures tissue metabolite profiles. Tumour metabolism can also be investigated using PET, with 18F-deoxyglucose being the most readily available tracer. This Review discusses these methods and the studies that have investigated their clinical use. A strong emphasis is placed on the measurement of quantitative parameters, which is a move away from the qualitative nature of conventional radiological reporting and presents major challenges, particularly for multicentre studies. PMID:23149894

Peet, Andrew C; Arvanitis, Theodoros N; Leach, Martin O; Waldman, Adam D

2012-11-13

51

Multiproject–multicenter evaluation of automatic brain tumor classification by magnetic resonance spectroscopy  

Microsoft Academic Search

Justification  Automatic brain tumor classification by MRS has been under development for more than a decade. Nonetheless, to our knowledge,\\u000a there are no published evaluations of predictive models with unseen cases that are subsequently acquired in different centers.\\u000a The multicenter eTUMOUR project (2004–2009), which builds upon previous expertise from the INTERPRET project (2000–2002) has\\u000a allowed such an evaluation to take place.

Juan M. García-Gómez; Jan Luts; Margarida Julià-Sapé; Patrick Krooshof; Salvador Tortajada; Javier Vicente Robledo; Willem Melssen; Elies Fuster-García; Iván Olier; Geert Postma; Daniel Monleón; Àngel Moreno-Torres; Jesús Pujol; Ana-Paula Candiota; M. Carmen Martínez-Bisbal; Johan Suykens; Lutgarde Buydens; Bernardo Celda; Sabine Van Huffel; Carles Arús; Montserrat Robles

2009-01-01

52

Preprocessing and Meta-Classification for Brain-Computer Interfaces  

Microsoft Academic Search

A brain-computer interface (BCI) is a system which allows direct translation of brain states into actions, bypassing the usual muscular pathways. A BCI system works by extracting user brain signals, applying machine learning algorithms to classify the user's brain state, and performing a computer-controlled action. Our goal is to improve brain state classification. Perhaps the most obvious way to improve

Paul S. Hammon; Virginia R. de Sa

2007-01-01

53

Intelligence and adaptive function in children diagnosed with brain tumour during infancy  

Microsoft Academic Search

Background  Late effects of treatment in children diagnosed and treated for brain tumours in infancy is a major concern. Assessment of infants presenting with brain tumours is difficult and there is little information available regarding the development of infants prior to treatment and hence the impact of the tumour itself on developmental outcomes.Aim  To describe the development of children diagnosed with brain

Robyn Stargatt; Jeffrey V. Rosenfeld; Vicki Anderson; Timothy Hassall; Wirginia Maixner; David Ashley

2006-01-01

54

Heterogeneous data fusion for brain tumor classification.  

PubMed

Current research in biomedical informatics involves analysis of multiple heterogeneous data sets. This includes patient demographics, clinical and pathology data, treatment history, patient outcomes as well as gene expression, DNA sequences and other information sources such as gene ontology. Analysis of these data sets could lead to better disease diagnosis, prognosis, treatment and drug discovery. In this report, we present a novel machine learning framework for brain tumor classification based on heterogeneous data fusion of metabolic and molecular datasets, including state-of-the-art high-resolution magic angle spinning (HRMAS) proton (1H) magnetic resonance spectroscopy and gene transcriptome profiling, obtained from intact brain tumor biopsies. Our experimental results show that our novel framework outperforms any analysis using individual dataset. PMID:22842996

Metsis, Vangelis; Huang, Heng; Andronesi, Ovidiu C; Makedon, Fillia; Tzika, Aria

2012-07-25

55

Brain tumour targeting strategies via coated ferrociphenol lipid nanocapsules.  

PubMed

In this study, a new active targeting strategy to favour ferrociphenol (FcdiOH) internalisation into brain tumour cells was developed by the use of lipid nanocapsules (LNCs) coated with a cell-internalising peptide (NFL-TBS.40-63 peptide) that interacts with tubulin-binding sites. In comparison, OX26 murine monoclonal antibodies (OX26-MAb) targeting transferrin receptors were also inserted onto the LNC surface. The incorporation of OX26 or peptide did not influence the in vitro antiproliferative effect of FcdiOH-LNCs on the 9L cells since their IC50 values were found in the same range. In vivo, intracerebral administration of OX26-FcdiOH-LNCs or peptide-FcdiOH-LNCs by convection enhanced delivery did not enhance the animal median survival time in comparison with untreated rats (25 days). Interestingly, intra-carotid treatment with peptide-FcdiOH-LNCs led to an ameliorated survival time of treated rats with the presence of animals surviving until days 35, 40 and 44. Such results were not obtained with OX26-MAbs, demonstrating the benefit of NFL-TBS.40-63 peptide as an active ligand for peripheral drug delivery to the brain tumours. PMID:22561953

Laine, Anne-Laure; Huynh, Ngoc Trinh; Clavreul, Anne; Balzeau, Julien; Béjaud, Jérôme; Vessieres, Anne; Benoit, Jean-Pierre; Eyer, Joël; Passirani, Catherine

2012-04-26

56

Protoporphyrin IX for photodynamic therapy of brain tumours  

NASA Astrophysics Data System (ADS)

Protoporphyrin IX (PpIX) displays high tumour-selective uptake following oral administration of 5-aminolaevulinic acid (ALA), a fact that is being exploited for the fluorescence-guided resection (FGR) and photodynamic therapy (PDT) of human brain malignancies. A clinical procedure for interstitial PDT (iPDT) has been established including pre-treatment planning, optical fiber insertion under stereotactic guidance and therapeutic irradiation at non-thermal fluence rates. We have previously reported on median survival in the range of 15 months and the existence of some intriguing long-term survivors (>5 years) following iPDT. Such successful treatments rely on for example sufficient light, PpIX and oxygen levels. We have investigated the absolute PpIX concentration as well as the PDT-induced photobleaching kinetics in brain tissues. Tissue samples acquired during FGR contained PpIX concentrations up to 28 ?M. This observation implies that ALA-induced PpIX levels are sufficient for inducing PDT effects in viable tumour tissue upon therapeutic irradiation. However, regions of pre-existing necrosis were characterised by significantly lower photosensitiser levels. Fluorescence spectroscopy was implemented in parallel to iPDT with the aim to employ PpIX photobleaching as a tool for realtime treatment supervision and early treatment prognosis.

Johansson, A.; Kreth, F. W.; Ardeshiri, A.; Stummer, W.; Schnell, O.; Herms, J.; Palte, G.; Beyer, W.; Stepp, H.

2010-04-01

57

Levetiracetam therapy in patients with brain tumour and epilepsy.  

PubMed

Epilepsy is a common clinical problem in patients with brain tumours, strongly affecting patients' quality of life. Tumour-related seizures are often difficult to control, and the clinical picture is complicated by frequent interactions between antiepileptic drugs (AEDs) and antineoplastic agents. We studied the safety and efficacy of levetiracetam (LEV), a new AED with a different pharmacological profile from traditional anticonvulsants, in 19 patients (6 females; age range 28-70 years, mean 48 years) with supratentorial gliomas and epilepsy. Seizure types were simple partial in four patients, complex partial in 4, complex partial with secondary generalization in 7, and generalized tonic-clonic in 4. LEV was added to the existing AED treatment on account of persisting seizures, and titrated at dosages of 1,000-3,000 mg/day. Patients were seen at the Outpatient's Centre every 1-3 months, and followed-up for 7-50 months (mean 25 months, median 20 months). At the end of the observation period, nine patients were seizure free (seizure free period ranging from 7 to 33 months, mean 16, median 12) and five patients reported an improvement in seizure-frequency from daily to weekly (n=1) or from weekly to monthly (n=3). Seizure frequency was unmodified in four patients and increased (from monthly to weekly) in one. No LEV-related adverse effects were observed. LEV plasma concentrations monitored in 12 subjects ranged from 11.9 to 82.1 microg/ml. Our preliminary open data indicate that add-on treatment with LEV in patients with brain tumours is safe and appears to be effective in reducing seizure frequency. Controlled studies on larger populations are warranted to confirm these open observations. PMID:16685465

Maschio, Marta; Albani, Fiorenzo; Baruzzi, Agostino; Zarabla, Alessia; Dinapoli, Loredana; Pace, Andrea; Pompili, Alfredo; Carapella, Carmine Maria; Occhipinti, Emanuele; Jandolo, Bruno

2006-05-10

58

Modulation of the blood–brain barrier in oncology: therapeutic opportunities for the treatment of brain tumours?  

Microsoft Academic Search

Systemically administered chemotherapy is not very effective in the treatment of primary or metastatic brain tumours. An important reason for this low efficacy is insufficient drug delivery to the tumour site due to the presence of the blood–brain barrier (BBB). In this review, we give an overview of strategies that were tested to bypass the BBB or to increase its

E. Marleen Kemper; Willem Boogerd; Ingrid Thuis; Jos H Beijnen; Olaf van Tellingen

2004-01-01

59

The use of PET in evaluating patients with primary brain tumours: is it useful?  

Microsoft Academic Search

During an 18 month period 39 patients were evaluated with [18F] fluorodeoxyglucose-PET (FDG-PET) for primary brain tumours. These included patients with suspected newly diagnosed tumours and patients with known tumours who were being evaluated for possible recurrence or increasing tumour grade. Scans were performed on a 951-31 Siemen's PET scanner with 4 mm resolution. Scanning time was about 20 minutes

W C Olivero; S C Dulebohn; J R Lister

1995-01-01

60

An intensive multiagent chemotherapy regimen for brain tumours occurring in very young children  

Microsoft Academic Search

Standard treatment for the majority of malignant brain tumours consists of surgery and radiotherapy. This treatment has late morbidity which is accentuated in the very young child. As part of a strategy to improve quality of life and overall survival of young children with brain tumours, members of the United Kingdom Children's Cancer Study Group (UKCCSG) have piloted an intensive

L S Lashford; R H Campbell; H R Gattamaneni; K Robinson; D Walker; C Bailey

1996-01-01

61

Classification trees for fast segmentation of DTI brain fiber tracts  

Microsoft Academic Search

A method is proposed for modeling and classification of White Matter fiber tracts in the brain. The presented scheme uses classification trees in conjunction with spatial representation of the individual fibers, in order to capture the characteristic behavior of fibers belonging to a specific anatomical structure. The method is characterized by high classification speed, under 3 seconds for all the

Gali Zimmerman-Moreno; Arnaldo Mayer; Hayit Greenspan

2008-01-01

62

Early rehabilitation after surgery improves functional outcome in inpatients with brain tumours.  

PubMed

Clinical experience suggests that application of the fundamental principles of rehabilitation medicine can improve the care of patients with cancer. Despite the high incidence of neurological and functional deficits in patients affected by brain tumours (BTs), rehabilitation treatment of this population is not as well established as it is for patients with other neurological conditions. To assess functional outcome in brain tumour inpatients who underwent early rehabilitation after surgery. 75 patients who had undergone neurosurgery for primary BTs and 75 patients affected by stroke were enrolled in a case-control study. All patients were evaluated by means of a core set of clinical scales (Functional Independence Measure, Sitting Balance score, Standing Balance score, Hauser Index, Massachusetts General Hospital Functional Ambulation Classification). Patients were evaluated before the beginning (T0) and at the end (T1) of rehabilitation treatment. The neurorehabilitation programme consisted of individual 60-min sessions of treatment, administered once a day, six days a week, for four consecutive weeks. Speech therapy was included when aphasia was diagnosed. All the measures of outcome were indicative of substantial improvements for neuro-oncological and for stroke patients (P = 0.000). Analysis of subgroups showed that patients affected by meningioma achieved better results (in efficiency terms) as regards independence in activities of daily living (P = 0.02) and mobility (P = 0.04) compared with patients affected by glioblastoma or stroke. Rehabilitation after surgery can improve functional outcome, justifying the delivery of rehabilitation services, even during the acute phase, to BTs inpatients, irrespective of tumour type. PMID:22124725

Bartolo, Michelangelo; Zucchella, Chiara; Pace, Andrea; Lanzetta, Gaetano; Vecchione, Carmine; Bartolo, Marcello; Grillea, Giovanni; Serrao, Mariano; Tassorelli, Cristina; Sandrini, Giorgio; Pierelli, Francesco

2011-11-29

63

Brain tumour and infiltrations dosimetry of boron neutron capture therapy combined with 252Cf brachytherapy.  

PubMed

This article presents a dosimetric investigation of boron neutron capture therapy (BNCT) combined with (252)Cf brachytherapy for brain tumour control. The study was conducted through computational simulation in MCNP5 code, using a precise and discrete voxel model of a human head, in which a hypothetical brain tumour was incorporated. A boron concentration ratio of 1:5 for healthy-tissue: tumour was considered. Absorbed and biologically weighted dose rates and neutron fluency in the voxel model were evaluated. The absorbed dose rate results were exported to SISCODES software, which generates the isodose surfaces on the brain. Analyses were performed to clarify the relevance of boron concentrations in occult infiltrations far from the target tumour, with boron concentration ratios of 1:1 up to 1:50 for healthy-tissue:infiltrations and healthy-tissue:tumour. The average biologically weighted dose rates at tumour area exceed up to 40 times the surrounding healthy tissue dose rates. In addition, the biologically weighted dose rates from boron have the main contribution at the infiltrations, especially far from primary tumour. In conclusion, BNCT combined with (252)Cf brachytherapy is an alternative technique for brain tumour treatment because it intensifies dose deposition at the tumour and at infiltrations, sparing healthy brain tissue. PMID:21705767

Brandão, Sâmia F; Campos, Tarcísio P R

2011-06-24

64

Classification of brain tumors using PCA-ANN  

Microsoft Academic Search

The present study is conducted to assist radiologists in marking tumor boundaries and in decision making process for multiclass classification of brain tumors. Primary brain tumors and secondary brain tumors along with normal regions are segmented by Gradient Vector Flow (GVF)-a boundary based technique. GVF is a user interactive model for extracting tumor boundaries. These segmented regions of interest (ROIs)

Vinod Kumar; Jainy Sachdeva; Indra Gupta; Niranjan Khandelwal; Chirag Kamal Ahuja

2011-01-01

65

Ethics roundtable debate: Child with severe brain damage and an underlying brain tumour  

Microsoft Academic Search

A young person presents with a highly malignant brain tumour with hemiparesis and limited prognosis after resection. She then\\u000a suffers an iatrogenic cardiac and respiratory arrest that results in profound anoxic encephalopathy. A difference in opinion\\u000a between the treatment team and the parent is based on a question of futile therapy. Opinions from five intensivists from around\\u000a the world explore

Scott Gunn; Satoru Hashimoto; Michael Karakozov; Thomas Marx; Ian KS Tan; Dan R Thompson; Jean-Louis Vincent

2004-01-01

66

Prenatal X-ray exposure and childhood brain tumours: a population-based case-control study on tumour subtypes  

PubMed Central

We investigated childhood brain tumours by histological subtype in relation to prenatal X-ray among all children, less than 15 years of age, born in Sweden between 1975 and 1984. For each case, one control was randomly selected from the Medical Birth Register, and exposure data on prenatal X-ray were extracted blindly from antenatal medical records. Additional information on maternal reproductive history was obtained from the Medical Birth Register. We found no overall increased risk for childhood brain tumour after prenatal abdominal X-ray exposure (adjusted odds ratio (OR): 1.02, 95% confidence interval (CI): 0.64–1.62); primitive neuroectodermal tumours had the highest risk estimate (OR: 1.88, 95% CI: 0.92–3.83).

Stalberg, K; Haglund, B; Axelsson, O; Cnattingius, S; Pfeifer, S; Kieler, H

2007-01-01

67

Pattern of self-organization in tumour systems: complex growth dynamics in a novel brain tumour spheroid model  

Microsoft Academic Search

We propose that a highly malignant brain tumour is an opportunistic, self- organizing and adaptive complex dynamic biosystem rather than an unorganized cell mass. To test the hypothesis of related key behaviour such as cell proliferation and invasion, we have developed a new in vitro assay capable of displaying several of the dynamic features of this multiparameter system in the

T. S. Deisboeck; M. E. Berens; A. R. Kansal; S. Torquato; A. O. Stemmer-Rachamimov; E. A. Chiocca

2001-01-01

68

Non-negative matrix factorisation methods for the spectral decomposition of MRS data from human brain tumours  

PubMed Central

Background In-vivo single voxel proton magnetic resonance spectroscopy (SV 1H-MRS), coupled with supervised pattern recognition (PR) methods, has been widely used in clinical studies of discrimination of brain tumour types and follow-up of patients bearing abnormal brain masses. SV 1H-MRS provides useful biochemical information about the metabolic state of tumours and can be performed at short (< 45 ms) or long (> 45 ms) echo time (TE), each with particular advantages. Short-TE spectra are more adequate for detecting lipids, while the long-TE provides a much flatter signal baseline in between peaks but also negative signals for metabolites such as lactate. Both, lipids and lactate, are respectively indicative of specific metabolic processes taking place. Ideally, the information provided by both TE should be of use for clinical purposes. In this study, we characterise the performance of a range of Non-negative Matrix Factorisation (NMF) methods in two respects: first, to derive sources correlated with the mean spectra of known tissue types (tumours and normal tissue); second, taking the best performing NMF method for source separation, we compare its accuracy for class assignment when using the mixing matrix directly as a basis for classification, as against using the method for dimensionality reduction (DR). For this, we used SV 1H-MRS data with positive and negative peaks, from a widely tested SV 1H-MRS human brain tumour database. Results The results reported in this paper reveal the advantage of using a recently described variant of NMF, namely Convex-NMF, as an unsupervised method of source extraction from SV1H-MRS. Most of the sources extracted in our experiments closely correspond to the mean spectra of some of the analysed tumour types. This similarity allows accurate diagnostic predictions to be made both in fully unsupervised mode and using Convex-NMF as a DR step previous to standard supervised classification. The obtained results are comparable to, or more accurate than those obtained with supervised techniques. Conclusions The unsupervised properties of Convex-NMF place this approach one step ahead of classical label-requiring supervised methods for the discrimination of brain tumour types, as it accounts for their increasingly recognised molecular subtype heterogeneity. The application of Convex-NMF in computer assisted decision support systems is expected to facilitate further improvements in the uptake of MRS-derived information by clinicians.

2012-01-01

69

Gene selection for brain cancer classification.  

PubMed

With the introduction of microarray, cancer classification, diagnosis and prediction are made more accurate and effective. However, the final outcome of the data analyses very much depend on the huge number of genes with relatively small number of samples present in each experiment. It is thus crucial to select relevant genes to be used for future specific cancer markers. Many feature selection methods have been proposed but none is able to classify all kinds of microarray data accurately, especially on those multi-class datasets. We propose a one-versus-one comparison method for selecting discriminatory features instead of performing the statistical test in a one-versus-all manner. Brain cancer is chosen as an example. Here, 3 types of statistics are used: signal-to-noise ratio (SNR), t-statistics and Pearson correlation coefficient. Results are verified by performing hierarchical and k-means clustering. Using our one-versus-one comparisons, best performance accuracies of 90.48% and 97.62% can be obtained by hierarchical and k-means clustering respectively. However best performance accuracies of 88.10% and 80.95% can be obtained respectively when using one-versus-all comparison. This shows that one-versus-one comparison is superior. PMID:17947170

Leung, Y Y; Chang, C Q; Hung, Y S; Fung, P C W

2006-01-01

70

What are the experiences of the child with a brain tumour and their parents?  

Microsoft Academic Search

Brain tumours are one of the most common forms of childhood cancer, affecting approximately 350 children in the UK each year (CancerBackup, 2005). The complex and long treatment for such tumours is often delivered in more than one place of care, as a result children and their families meet a large number of healthcare professionals from a variety of disciplines.

Louise Soanes; Darren Hargrave; Lauren Smith; Faith Gibson

2009-01-01

71

Elemental regional distribution in human brain tumours - PIXE analysis of biopsy and autopsy samples  

NASA Astrophysics Data System (ADS)

The elemental regional distribution in human brain tissue was obtained using PIXE analysis. A histo-pathological investigation was used to classify the samples into three different groups: (1) normal tissue, (2) tumour front and (3) tumour centre. Significant differences between the mean values of phosphorous, calcium, iron, zinc and selenium concentrations in each group are reported.

Tapper, U. A. S.; Malmqvist, K. G.; Brun, A.; Salford, L. G.

1987-03-01

72

A mathematical model of the treatment and survival of patients with high-grade brain tumours  

Microsoft Academic Search

More years of life per patient are lost as the result of primary brain tumours than any other form of cancer. The most aggressive of these is known as glioblastoma (GBM). The median survival time of patients with GBM is under 10 months and the outlook has hardly improved over the past 20 years. Generally, these tumours are remarkably resistant

Norman F. Kirkby; Sarah J. Jefferies; Raj Jena; Neil G. Burnet

2007-01-01

73

Genomics and Metabolomics Research for Brain Tumour Diagnosis Based on Machine Learning  

Microsoft Academic Search

The incorporation of new biomedical technologies in the diagnosis and prognosis of cancer is changing medicine to an evidence-based\\u000a diagnosis. We summarize some studies related to brain tumour research in Europe, based on the metabolic information provided\\u000a by in vivo Magnetic Resonance Spectroscopy (MRS) and transcriptomic profiling observed by DNA microarrays. The first result\\u000a presents the improvement in brain tumour

Juan Miguel García-gómez; Salvador Tortajada; Javier Vicente; Carlos Sáez; Xavier Castells; Jan Luts; Margarida Julià-sapé; Alfons Juan-císcar; Sabine Van Huffel; Anna Barcelo; Joaquín Ariño; Carles Arús; Montserrat Robles

2007-01-01

74

SMART syndrome: a late reversible complication after radiation therapy for brain tumours.  

PubMed

With intensified treatment leading to longer survival, complications of therapy for brain tumours are more frequently observed. Regarding radiation therapy, progressive and irreversible white matter disease with cognitive decline is most feared. We report on four patients with reversible clinical and radiological features occurring years after radiation for brain tumours, suggestive for the so called SMART syndrome (stroke-like migraine attacks after radiation therapy). All four patients (males, age 36-60 years) had been treated with focal brain radiation for a primary brain tumour or with whole-brain radiation therapy for brain metastases. Ranging from 2 to 10 years following radiation therapy patients presented with headache and focal neurological deficits, suggestive for tumour recurrence. Two patients also presented with focal seizures. MRI demonstrated typical cortical swelling and contrast enhancement, primarily in the parieto-occipital region. On follow-up both clinical and MRI features improved spontaneously. Three patients eventually proved to have tumour recurrence. The clinical and radiological picture of these patients is compatible with the SMART syndrome, a rare complication of radiation therapy which is probably under recognized in brain tumour patients. The pathophysiology of the SMART syndrome is poorly understood but bears similarities with the posterior reversible encephalopathy syndrome (PRES). These four cases underline that the SMART syndrome should be considered in patients formerly treated with radiation therapy for brain tumours, who present with new neurologic deficits. Before the diagnosis of SMART syndrome can be established other causes, such as local tumour recurrence, leptomeningeal disease or ischemic disease should be ruled out. PMID:21373901

Kerklaan, Joost P; Lycklama á Nijeholt, Geert J; Wiggenraad, Ruud G J; Berghuis, Bianca; Postma, Tjeerd J; Taphoorn, Martin J B

2011-03-04

75

SMART syndrome: a late reversible complication after radiation therapy for brain tumours  

Microsoft Academic Search

With intensified treatment leading to longer survival, complications of therapy for brain tumours are more frequently observed.\\u000a Regarding radiation therapy, progressive and irreversible white matter disease with cognitive decline is most feared. We report\\u000a on four patients with reversible clinical and radiological features occurring years after radiation for brain tumours, suggestive\\u000a for the so called SMART syndrome (stroke-like migraine attacks

Joost P. KerklaanGeert; Geert J. Lycklama á Nijeholt; Ruud G. J. Wiggenraad; Bianca Berghuis; Tjeerd J. Postma; Martin J. B. Taphoorn

2011-01-01

76

Supportive care needs of people with brain tumours and their carers  

Microsoft Academic Search

Goals of work  The diagnosis and treatment of a brain tumour may result in long-term changes in a patient’s functional and social abilities and\\/or in a greatly reduced life span. A qualitative investigation was conducted to examine the supportive care needs of patients with brain tumour and their carers.Materials and methods  Overall, 18 patients and 18 carers participated in focus groups or

Monika Janda; Elizabeth G. Eakin; Lucy Bailey; David Walker; Kate Troy

2006-01-01

77

Comparison of contrast in brightness mode and strain ultrasonography of glial brain tumours  

PubMed Central

Background Image contrast between normal tissue and brain tumours may sometimes appear to be low in intraoperative ultrasound. Ultrasound imaging of strain is an image modality that has been recently explored for intraoperative imaging of the brain. This study aims to investigate differences in image contrast between ultrasound brightness mode (B-mode) images and ultrasound strain magnitude images of brain tumours. Methods Ultrasound radiofrequency (RF) data was acquired during surgery in 15 patients with glial tumours. The data were subsequently processed to provide strain magnitude images. The contrast in the B-mode images and the strain images was determined in assumed normal brain tissue and tumour tissue at selected regions of interest (ROI). Three measurements of contrast were done in the ultrasound data for each patient. The B-mode and strain contrasts measurements were compared using the paired samples t- test. Results The statistical analysis of a total of 45 measurements shows that the contrasts in the strain magnitude images are significantly higher than in the conventional ultrasound B-mode images (P?brain tissue and glial tumour tissue than conventional ultrasound B-mode imaging. Ultrasound imaging of tissue strain therefore holds the potential of becoming a valuable adjunct to conventional intraoperative ultrasound imaging in brain tumour surgery.

2012-01-01

78

MR imaging-guided cryoablation of metastatic brain tumours: initial experience in six patients  

Microsoft Academic Search

Objective  The objective was to evaluate the initial experience and safety of magnetic resonance imaging (MRI)-guided transcranial cryoablation\\u000a in cystic metastatic brain tumours.\\u000a \\u000a \\u000a \\u000a Material and methods  Seven cystic metastatic brain tumours in six patients were treated with cryoablation. The approval from the local ethics committee\\u000a and individual patient consent were acquired before the study. Before the procedure the tumours were detected with

Chengli Li; Lebin Wu; Jiqing Song; Ming Liu; Yubo Lv; Roberto Blanco Sequeiros

2010-01-01

79

Influence of GSM Microwaves on Fractal Structure of brain tumours  

Microsoft Academic Search

Fractal dimension of C-6 rat glioma tumours growing in microwave field generated by signal simulation of the Global System for Mobile communications (GSM) with frequency 960 MHz was found significantly enhanced as compared with field free tumours growing at different temperatures. The Mandelbrot answer to Richardson question: \\

M. Babincová; P. Sourivong; D. Leszczynska; P. Babinec

2003-01-01

80

Flow-through fluorocytophotometry of different brain tumours  

Microsoft Academic Search

The flow-through cytophotometric method was used to investigate the single-cell DNA content in 60 tumours of the CNS and allied structures (9 meningiomas, 5 ependymomas, 15 astrocytomas, 11 anaplastic astrocytomas, 8 glioblastomas, 7 medulloblastomas, 2 oligodendrogliomas, 1 anaplastic oligodendroglioma, and 2 neurinomas). The cytophotometric parameters were correlated with morphological and clinical data of the tumours. The results are summarised in

J. Lehmann; H. Krug

1980-01-01

81

Virtual brain tumours (gliomas) enhance the reality of medical imaging and highlight inadequacies of current therapy  

Microsoft Academic Search

Gliomas are brain tumours that differ from most other cancers by their diffuse invasion of the surrounding normal tissue and their notorious recurrence following all forms of therapy. We have developed a mathematical model to quantify the spatio- temporal growth and invasion of gliomas in three dimensions throughout a virtual human brain. The model quantifies the extent of tumorous invasion

KR Swanson; EC Alvord Jr; JD Murray

82

The creation of protection and hope in patients with malignant brain tumours  

Microsoft Academic Search

The malignant brain tumour disease condenses much of the anguish of cancer diseases. The brain is a vital and delicate organ, and the prognosis is generally unfavourable. The patient is exposed and has to rely on cognitive manoeuvres to manage the mental stress. The purpose of this study was to generate new insights into how the patient constructs a new

Pär Salander; Tommy Bergenheim; Roger Henriksson

1996-01-01

83

Virtual brain tumours (gliomas) enhance the reality of medical imaging and highlight inadequacies of current therapy  

Microsoft Academic Search

Gliomas are brain tumours that differ from most other cancers by their diffuse invasion of the surrounding normal tissue and their notorious recurrence following all forms of therapy. We have developed a mathematical model to quantify the spatio-temporal growth and invasion of gliomas in three dimensions throughout a virtual human brain. The model quantifies the extent of tumorous invasion of

K R Swanson; E C Alvord; J D Murray

2002-01-01

84

Diagnostic segregation of human brain tumours using Fourier-transform infrared and/or Raman spectroscopy coupled with discriminant analysis†  

PubMed Central

The most common initial treatment received by patients with a brain tumour is surgical removal of the growth. Precise histopathological diagnosis of brain tumours is to some extent subjective. Furthermore, currently available diagnostic imaging techniques to delineate the excision border during cytoreductive surgery lack the required spatial precision to aid surgeons. We set out to determine whether infrared (IR) and/or Raman spectroscopy combined with multivariate analysis could be applied to discriminate between normal brain tissue and different tumour types (meningioma, glioma and brain metastasis) based on the unique spectral “fingerprints” of their biochemical composition. Formalin-fixed paraffin-embedded tissue blocks of normal brain and different brain tumours were de-waxed, mounted on low-E slides and desiccated before being analyzed using attenuated total reflection Fourier-transform IR (ATR-FTIR) and Raman spectroscopy. ATR-FTIR spectroscopy showed a clear segregation between normal and different tumour subtypes. Discrimination of tumour classes was also apparent with Raman spectroscopy. Further analysis of spectral data revealed changes in brain biochemical structure associated with different tumours. Decreased tentatively-assigned lipid-to-protein ratio was associated with increased tumour progression. Alteration in cholesterol esters-to-phenylalanine ratio was evident in grade IV glioma and metastatic tumours. The current study indicates that IR and/or Raman spectroscopy have the potential to provide a novel diagnostic approach in the accurate diagnosis of brain tumours and have potential for application in intra-operative diagnosis.

Gajjar, Ketan; Heppenstall, Lara D.; Pang, Weiyi; Ashton, Katherine M.; Trevisan, Julio; Patel, Imran I.; Llabjani, Valon; Stringfellow, Helen F.; Martin-Hirsch, Pierre L.; Dawson, Timothy; Martin, Francis L.

2013-01-01

85

Simple Fully Automated Group Classification on Brain fMRI  

SciTech Connect

We propose a simple, well grounded classification technique which is suited for group classification on brain fMRI data sets that have high dimensionality, small number of subjects, high noise level, high subject variability, imperfect registration and capture subtle cognitive effects. We propose threshold-split region as a new feature selection method and majority voteas the classification technique. Our method does not require a predefined set of regions of interest. We use average acros ssessions, only one feature perexperimental condition, feature independence assumption, and simple classifiers. The seeming counter-intuitive approach of using a simple design is supported by signal processing and statistical theory. Experimental results in two block design data sets that capture brain function under distinct monetary rewards for cocaine addicted and control subjects, show that our method exhibits increased generalization accuracy compared to commonly used feature selection and classification techniques.

Honorio, J.; Goldstein, R.; Honorio, J.; Samaras, D.; Tomasi, D.; Goldstein, R.Z.

2010-04-14

86

Overexpression of the p53-inducible brain-specific angiogenesis inhibitor 1 suppresses efficiently tumour angiogenesis  

Microsoft Academic Search

The brain-specific angiogenesis inhibitor 1 gene has been isolated in an attempt to find fragments with p53 “functional” binding sites. As reported herein and by others, brain-specific angiogenesis inhibitor 1 expression is present in some normal tissues, but is reduced or lost in tumour tissues. Such data and its particular structure prompted the hypothesis that brain-specific angiogenesis inhibitor 1 may

D G Duda; M Sunamura; L Lozonschi; T Yokoyama; T Yatsuoka; F Motoi; A Horii; K Tani; S Asano; Y Nakamura; S Matsuno

2002-01-01

87

Risk of second brain tumour after conservative surgery and radiotherapy for pituitary adenoma  

Microsoft Academic Search

OBJECTIVE--To assess the risk of second brain tumour in patients with pituitary adenoma treated with conservative surgery and external beam radiotherapy. DESIGN--Long term follow up of a cohort of patients with pituitary adenoma and comparison of tumour occurrence with population incidence rates. SETTING--The Royal Marsden Hospital. SUBJECTS--334 patients with pituitary adenoma treated with conservative surgery and radiotherapy (median dose 45

M. Brada; D. Ford; S. Ashley; J. M. Bliss; S. Crowley; M. Mason; B. Rajan; D. Traish

1992-01-01

88

Bone morphogenetic proteins inhibit the tumorigenic potential of human brain tumour-initiating cells  

Microsoft Academic Search

Transformed, oncogenic precursors, possessing both defining neural-stem-cell properties and the ability to initiate intracerebral tumours, have been identified in human brain cancers. Here we report that bone morphogenetic proteins (BMPs), amongst which BMP4 elicits the strongest effect, trigger a significant reduction in the stem-like, tumour-initiating precursors of human glioblastomas (GBMs). Transient in vitro exposure to BMP4 abolishes the capacity of

S. G. M. Piccirillo; B. A. Reynolds; N. Zanetti; G. Lamorte; E. Binda; G. Broggi; H. Brem; A. Olivi; F. Dimeco; A. L. Vescovi

2006-01-01

89

Brain tumours and exposure to pesticides: a case-control study in southwestern France  

PubMed Central

Background Brain tumours are often disabling and rapidly lethal; their aetiology is largely unknown. Among potential risk factors, pesticides are suspected. Objective To examine the relationship between exposure to pesticides and brain tumours in adults in a population?based case–control study in southwestern France. Methods Between May 1999 and April 2001, 221 incident cases of brain tumours and 442 individually matched controls selected from the general population were enrolled. Histories of occupational and environmental exposures, medical and lifestyle information were collected. A cumulative index of occupational exposure to pesticides was created, based on expert review of lifelong jobs and tasks. Separate analyses were performed for gliomas and meningiomas. Results A non?statistically significant increase in risk was found for brain tumours when all types of occupational exposure to pesticides were considered (OR?=?1.29, 95% CI 0.87 to 1.91) and slightly higher but still non?statistically significant when gliomas were considered separately (OR?=?1.47, 95% CI 0.81 to 2.66). In the highest quartile of the cumulative index, a significant association was found for brain tumours (OR?=?2.16, 95% CI 1.10 to 4.23) and for gliomas (OR?=?3.21, 95% CI 1.13 to 9.11), but not for meningiomas. A significant increase in risk was also seen for the treatment of home plants (OR?=?2.24, 95% CI 1.16 to 4.30) owing to environmental exposure to pesticides. Conclusions These data suggest that a high level of occupational exposure to pesticides might be associated with an excess risk of brain tumours, and especially of gliomas.

Provost, Dorothee; Cantagrel, Anne; Lebailly, Pierre; Jaffre, Anne; Loyant, Veronique; Loiseau, Hugues; Vital, Anne; Brochard, Patrick; Baldi, Isabelle

2007-01-01

90

Electroencephalogram signals processing for topographic brain mapping and epilepsies classification  

Microsoft Academic Search

In this study, topographic brain mapping and wavelet transform–neural network method are used for the classification of grand mal (clonic stage) and petit mal (absence) epilepsies into healthy, ictal and interictal (EEGs). Preprocessing is included to remove artifacts occurred by blinking, wandering baseline (electrodes movement) and eyeball movement using the Discrete Wavelet Transformation (DWT). De-noising EEG signals from the AC

Mohammad Reza Arab; Amir Abolfazl Suratgar; Alireza Rezaei Ashtiani

2010-01-01

91

Targeting brain gliomas energy metabolism for classification purposes  

Microsoft Academic Search

The aim of this study is to reveal the discriminative potential of energy related metabolites in brain gliomas classification. The proposed analysis considers two aspects, the statistical and biological verification of metabolites' effects. In particular, Magnetic Resonance Spectroscopic Imaging (MRSI) is first employed for the statistical evaluation of metabolites. Five of the identified significant metabolites, namely glucose, pyruvate, lactate, alanine

M. G. Kounelakis; M. E. Zervakis; G. J. Postma; L. M. C. Buydens; G. C. Giakos; C. Narayan; S. Marotta; D. Natarajamani; X. Kotsiakis

2010-01-01

92

Brain MRI Tissue Classification Based on Local Markov Random Fields  

PubMed Central

A new method for tissue classification of brain magnetic resonance images (MRI) of the brain is proposed. The method is based on local image models where each models the image content in a subset of the image domain. With this local modeling approach, the assumption that tissue types have the same characteristics over the brain needs not to be evoked. This is important because tissue type characteristics, such as T1 and T2 relaxation times and proton density, vary across the individual brain and the proposed method offers improved protection against intensity non-uniformity artifacts that can hamper automatic tissue classification methods in brain MRI. A framework in which local models for tissue intensities and Markov Random Field priors are combined into a global probabilistic image model is introduced. This global model will be an inhomogeneous Markov Random Field and it can be solved by standard algorithms such as iterative conditional modes. The division of the whole image domain into local brain regions possibly having different intensity statistics is realized via sub-volume probabilistic atlases. Finally, the parameters for the local intensity models are obtained without supervision by maximizing the weighted likelihood of a certain finite mixture model. For the maximization task, a novel genetic algorithm almost free of initialization dependency is applied. The algorithm is tested on both simulated and real brain MR images. The experiments confirm that the new method offers a useful improvement of the tissue classification accuracy when the basic tissue characteristics vary across the brain and the noise level of the images is reasonable. The method also offers better protection against intensity non-uniformity artifact than the corresponding method based on a global (whole image) modeling scheme.

Dinov, Ivo D.; Shattuck, David W.; Toga, Arthur W.

2010-01-01

93

Theoretical considerations in relation to the treatment of brain tumours by means of local hyperthermia generated by ultrasound fields.  

PubMed

Brain tumours comprise a significant fraction of all tumours in the human body. Despite the development of technology in clinical oncology, these tumours still present a difficult challenge. The margin between destruction of tumour and damage to normal tissue is narrow in the brain. The price paid for producing tissue damage outside the tumour is high in terms of quality of survival. Results of many experiments with ultrasound hyperthermia show that this new technique is successful for treating certain types of malignant tumours. In the case of brain tumours, applying focused fields should have the advantage of selectively destroying the tumour and leaving surrounding tissues intact. Previous attempts at applying ultrasound to the field of neurosurgery are reviewed. Those factors which have effects on the generation of thermal fields in brain tissues are considered in relation to the possible treatment of human brain tumours. Calculated thermal fields in a 2-D brain model generated by an applicator built in our laboratory are also presented. PMID:1936292

Quan, K M; Watmough, D J; Mallard, J R

1991-10-01

94

Characterisation of Walker 256 breast carcinoma cells from two tumour cell banks as assessed using two models of secondary brain tumours  

PubMed Central

Background Metastatic brain tumours are a common end stage of breast cancer progression, with significant associated morbidity and high mortality. Walker 256 is a rat breast carcinoma cell line syngeneic to Wistar rats and commonly used to induce secondary brain tumours. Previously there has been the assumption that the same cancer cell line from different cell banks behave in a similar manner, although recent studies have suggested that cell lines may change their characteristics over time in vitro. Methods In this study internal carotid artery injection and direct cerebral inoculation models of secondary brain tumours were used to determine the tumorigenicity of Walker 256 cells obtained from two cell banks, the American Type Culture Collection (ATCC), and the Cell Resource Centre for Medical Research at Tohoku University (CRCTU). Results Tumour incidence and volume, plus immunoreactivity to albumin, IBA1 and GFAP, were used as indicators of tumorigenicity and tumour interaction with the host brain microenvironment. CRCTU Walker 256 cells showed greater incidence, larger tumour volume, pronounced blood–brain barrier disruption and prominent glial response when compared to ATCC cell line. Conclusions These findings indicate that immortalised cancer cell lines obtained from different cell banks may have diverse characteristics and behaviour in vivo.

2013-01-01

95

Strain processing of intraoperative ultrasound images of brain tumours: Initial results  

Microsoft Academic Search

The purpose of the study was to investigate a method for strain calculation and its ability to discriminate between brain tumour and normal brain. During surgery of a low-grade astrocytoma and a metastasis, we acquired ultrasound (US) radiofrequency (RF) data with a hand-held probe at the dura mater. Using cross-correlation and phase-sensitive processing, we quantified the tissue displacements between consecutive

Tormod Selbekk; Jon Bang; Geirmund Unsgaard

2005-01-01

96

Childhood brain tumour information on the Internet in the Chinese language  

Microsoft Academic Search

Background  Internet information, now available in many different languages, can become a major source of information for patients and families in their own mother tongue. Chinese represent one of most frequently spoken language in the world. The aims of this study were to critically appraise the quantity and quality of Internet health information in childhood brain tumour in the Chinese language

Loretta Lau; Darren R. Hargrave; Ute Bartels; Carlos Esquembre; Eric Bouffet

2006-01-01

97

Use of cellular telephones and brain tumour risk in urban and rural areas  

Microsoft Academic Search

Aims: To investigate the association between the use of cellular or cordless telephones and the risk for brain tumours in different geographical areas, urban and rural.Methods: Patients aged 20–80 years, living in the middle part of Sweden, and diagnosed between 1 January 1997 and 30 June 2000 were included. One control matched for sex and age in five year age

L Hardell; M Carlberg; K Hansson Mild

2005-01-01

98

Paediatric brain tumours treated at a single, tertiary paediatric neurosurgical referral centre from 1999 to 2010 in Australia.  

PubMed

Paediatric brain tumours are the most common solid tumour of childhood and the most common cancer cause of death among children. A retrospective review of 313 histopathologically proven brain tumours over an 11-year period has been performed at the Children's Hospital Westmead, New South Wales, Australia, to determine proportions and locations of different tumours, age distribution, survival rates and usage of various treatment modalities. Pilocytic astrocytoma was the most common paediatric brain tumour (29%) followed by medulloblastoma (12%) and ependymoma (6%). Most tumours were histologically benign (59%), and 42% of tumours were located in the posterior fossa. The average age at diagnosis was 7.9 years. About 50% of children were treated with surgery alone, whereas the other 50% had surgery or biopsy plus adjuvant treatment. The overall one-year survival rate was 89% and the five-year survival rate was 80%. The five-year survival rates for pilocytic astrocytoma was 91%; medulloblastoma, 75%; ependymoma, 82%; and high grade glioma, 15%. Thus, a large proportion of paediatric brain tumours were histologically benign and were treated with surgery alone, but a subset of benign tumours required adjuvant treatment and were associated with mortality (25%). The overall survival rates were high and are improving, although for some tumours, such as high grade glioma, the outlook remains poor. PMID:22898201

Ramanan, Mahesh; Chaseling, Raymond

2012-08-14

99

Oesophageal squamous cell carcinoma: relationship between fluorine-18 fludeoxyglucose positron emission tomography CT maximum standardised uptake value, metabolic tumour volume, and tumour, node and metastasis classification  

PubMed Central

Objectives We aimed to evaluate the relationships between primary tumour, maximum standardised uptake value, metabolic tumour volume and seventh edition American Joint Committee on Cancer (AJCC) classification in oesophageal squamous cell carcinoma (OSCC) patients. Methods Fluorine-18 fludeoxyglucose (18F-FDG) positron emission tomography (PET)-CT scans of 41 consecutive newly diagnosed OSCC patients were retrospectively reviewed. Maximum standard uptake value (SUVmax) and metabolic tumour volume (MTV) were recorded. Two-tailed Spearman's correlation was used to analyse the relationships between the metabolic parameters and the AJCC staging system. Results Positive correlations were observed between SUVmax, MTV and tumour (T) stage, in addition to node (N) stage and AJCC stage. Both metabolic parameters were independent variables that significantly affected the N stage and AJCC stage, and SUVmax was the only independent variable that significantly affected the T stage. Conclusion The metabolic parameters derived from 18F-FDG PET-CT were positively correlated with T, N and AJCC stage in primary OSCC. Our findings may suggest a complementary role of these parameters to seventh-edition AJCC staging in the prognostication of OSCC patients.

Zhu, W-Q; Sun, X; Xing, L; Li, M; Yue, J; Qu, W; Sun, X; Kong, L; Yu, J

2012-01-01

100

Classification of Traumatic Brain Injury for Targeted Therapies  

PubMed Central

Abstract The heterogeneity of traumatic brain injury (TBI) is considered one of the most significant barriers to finding effective therapeutic interventions. In October, 2007, the National Institute of Neurological Disorders and Stroke, with support from the Brain Injury Association of America, the Defense and Veterans Brain Injury Center, and the National Institute of Disability and Rehabilitation Research, convened a workshop to outline the steps needed to develop a reliable, efficient and valid classification system for TBI that could be used to link specific patterns of brain and neurovascular injury with appropriate therapeutic interventions. Currently, the Glasgow Coma Scale (GCS) is the primary selection criterion for inclusion in most TBI clinical trials. While the GCS is extremely useful in the clinical management and prognosis of TBI, it does not provide specific information about the pathophysiologic mechanisms which are responsible for neurological deficits and targeted by interventions. On the premise that brain injuries with similar pathoanatomic features are likely to share common pathophysiologic mechanisms, participants proposed that a new, multidimensional classification system should be developed for TBI clinical trials. It was agreed that preclinical models were vital in establishing pathophysiologic mechanisms relevant to specific pathoanatomic types of TBI and verifying that a given therapeutic approach improves outcome in these targeted TBI types. In a clinical trial, patients with the targeted pathoanatomic injury type would be selected using an initial diagnostic entry criterion, including their severity of injury. Coexisting brain injury types would be identified and multivariate prognostic modeling used for refinement of inclusion/exclusion criteria and patient stratification. Outcome assessment would utilize endpoints relevant to the targeted injury type. Advantages and disadvantages of currently available diagnostic, monitoring, and assessment tools were discussed. Recommendations were made for enhancing the utility of available or emerging tools in order to facilitate implementation of a pathoanatomic classification approach for clinical trials.

Saatman, Kathryn E.; Duhaime, Ann-Christine; Bullock, Ross; Maas, Andrew I.R.; Valadka, Alex

2008-01-01

101

Analysis of Fluid in Cysts Accompanying Various Primary and Metastatic Brain Tumours: Proteins, Lactate and pH  

Microsoft Academic Search

Summary   There is a growing interest in cystic lesions of the brain. By examining the cyst content of brain tumours more insight into\\u000a the pathogenesis of cyst formation has been found. In this study, 39 samples of cyst fluid of 34 patients with a cyst accompanying\\u000a a brain tumour were collected and studied biochemically regarding their protein content, lactate and

P. N. M. Lohle; H. A. L. Wurzer; P. J. Seelen; L. M. Kingma; K. G. Go

1998-01-01

102

Role of diffusion-weighted echo-planar MRI in distinguishing between brain abscess and tumour: a preliminary report  

Microsoft Academic Search

Our purpose was to evaluate diffusion-weighted (DW) echo-planar MRI in differentiating between brain abscess and tumour.\\u000a We examined two patients with surgically confirmed pyogenic brain abscess and 18 with metastatic brain tumours or high-grade\\u000a glioma, using a 1.5 T system. The apparent diffusion coefficient (ADC) of each necrotic or solid contrast-enhancing lesion\\u000a was measured with two different b values (20

K. Noguchi; N. Watanabe; T. Nagayoshi; T. Kanazawa; S. Toyoshima; M. Shimizu; H. Seto

1999-01-01

103

Photodynamic therapy of malignant brain tumours: A complementary approach to conventional therapies.  

PubMed

The poor outcome of primary malignant brain tumours is predominantly due to local invasion and local recurrence and their prognosis is highly dependent on the degree of resection. They have no border and, at best, a marginal zone that remains invisible to the surgeon. Photodynamic therapy (PDT) appears to be an interesting modality to fill the need for a targeted treatment that may reduce recurrence and extend survival with minimal side effects. In this review, we summarize the different technologies of brain tumour PDT employed such as interstitial PDT, and PDT-associated surgical resection, describing new light delivery devices. The role of dosimetry - one of the key factors behind successful brain tumour PDT - is discussed. This can be achieved by integrating results from in vivo studies. In this context, the development of new therapeutic photosensitizer delivery systems is also an area of significant research interest. Multifunctionality can be engineered into a single nanoplatform to provide tumour-specific detection, treatment, and follow-up. Such multitasking systems appear to be complementary to conventional technologies. PMID:22858248

Bechet, Denise; Mordon, Serge R; Guillemin, François; Barberi-Heyob, Muriel A

2012-08-01

104

Intra-operative 3-T MRI for paediatric brain tumours: challenges and perspectives.  

PubMed

MRI is the ideal modality for imaging intracranial tumours. Intraoperative MRI (ioMRI) makes it possible to obtain scans during a neurosurgical operation that can aid complete macroscopic tumour resection—a major prognostic factor in the majority of brain tumours in children. Intraoperative MRI can also help limit damage to normal brain tissue. It therefore has the potential to improve the survival of children with brain tumours and to minimise morbidity, including neurological deficits. The use of ioMRI is also likely to reduce the need for second look surgery, and may reduce the need for chemotherapy and radiotherapy. Highfield MRI systems provide better anatomical information and also enable effective utilisation of advanced MRI techniques such as perfusion imaging, diffusion tensor imaging, and magnetic resonance spectroscopy. However, high-field ioMRI facilities require substantial capital investment, and careful planning is required for optimal benefit. Safe ioMRI requires meticulous attention to detail and rigorous application of magnetic field safety precautions. Interpretation of ioMRI can be challenging and requires experience and understanding of artefacts that are common in the intra-operative setting. PMID:22286342

Abernethy, L J; Avula, S; Hughes, G M; Wright, E J; Mallucci, C L

2012-02-01

105

Imaging patients with suspected brain tumour: guidance for primary care  

PubMed Central

The number of referrals by primary care practitioners to secondary care neurology services, particularly for headache, may be difficult to justify. Access to imaging by primary care practitioners could avoid referral without compromising patient outcomes, but the decision to refer is based on a number of complex factors. Due to the paucity of rigorous evidence in this area, available data are combined with expert opinion to offer support for GPs. The study suggests management for three levels of risk of tumour: red flags >1%; orange flags 0.1–1%; and yellow flags <0.1% but above the background population rate of 0.01%. Clinical presentations are stratified into these three groups. Important secondary causes of headache where imaging is normal should not be overlooked, and normal investigation does not eliminate the need for follow-up or appropriate management of headache.

Kernick, David P; Ahmed, Fayyaz; Bahra, Anish; Dowson, Andrew; Elrington, Giles; Fontebasso, Manuela; Giffin, Nicola J; Lipscombe, Sue; MacGregor, Anne; Peatfield, Richard; Weatherby, Stuart; Whitmarsh, Tom; Goadsby, Peter J

2008-01-01

106

Imaging patients with suspected brain tumour: guidance for primary care.  

PubMed

The number of referrals by primary care practitioners to secondary care neurology services, particularly for headache, may be difficult to justify. Access to imaging by primary care practitioners could avoid referral without compromising patient outcomes, but the decision to refer is based on a number of complex factors. Due to the paucity of rigorous evidence in this area, available data are combined with expert opinion to offer support for GPs. The study suggests management for three levels of risk of tumour: red flags>1%; orange flags 0.1-1%; and yellow flags<0.1% but above the background population rate of 0.01%. Clinical presentations are stratified into these three groups. Important secondary causes of headache where imaging is normal should not be overlooked, and normal investigation does not eliminate the need for follow-up or appropriate management of headache. PMID:19068162

Kernick, David P; Ahmed, Fayyaz; Bahra, Anish; Dowson, Andrew; Elrington, Giles; Fontebasso, Manuela; Giffin, Nicola J; Lipscombe, Sue; MacGregor, Anne; Peatfield, Richard; Weatherby, Stuart; Whitmarsh, Tom; Goadsby, Peter J

2008-12-01

107

Diffusion Tensor Imaging of Brain Tumours at 3 T: A Potential Tool for Assessing White Matter Tract Invasion?  

Microsoft Academic Search

AIM: To determine whether diffusion tensor imaging (DTI) of brain tumours can demonstrate abnormalities distal to hyperintensities on T2-weighted images, and possibly relate these to tumour grade.MATERIALS AND METHODS: Twenty patients with histologically confirmed supratentorial tumours, both gliomas (high and low grade) and metastases, were imaged at 3T using T2-weighted and DTI sequences. Regions of interest (ROI) were drawn within

S. J. Price; N. G. Burnet; T. Donovan; H. A. L. Green; A. Peña; N. M. Antoun; J. D. Pickard; T. A. Carpenter; J. H. Gillard

2003-01-01

108

Reaching a moveable visual target: dissociations in brain tumour patients.  

PubMed

Damage to the posterior parietal cortex (PPC) can lead to Optic Ataxia (OA), in which patients misreach to peripheral targets. Recent research suggested that the PPC might be involved not only in simple reaching tasks toward peripheral targets, but also in changing the hand movement trajectory in real time if the target moves. The present study investigated whether patients with a lesion arising from operation for prefrontal, premotor or parietal tumours are selectively impaired in three experimental pointing conditions: (i) pointing to peripheral targets, (ii) pointing to fixatable targets, and (iii) pointing to moved targets (on-line movement corrections). The study confirmed the selective importance of the parietal cortex in all three tasks. Surprisingly, given clinical claims about OA, the degree of peripheral reaching errors correlated strongly in parietal patients with that to fixatable targets. However, there was no relation between peripheral reaching errors and the 'shift cost' of making on-line correction to moved targets, and classical double dissociations between the two skills were observed. The findings suggest that deficits in pointing to peripheral and to moved targets reflect two at least partly independent processes. PMID:23501699

Buiatti, Tania; Skrap, Miran; Shallice, Tim

2013-03-16

109

Interaction between human brain tumour biopsies and fetal rat brain tissue in vitro  

Microsoft Academic Search

The invasiveness of human intracranial tumours was studied in an organ culture system. Biopsies from six glioblastomas, four astrocytomas, two mixed gliomas, one ependymoma, four meningiomas and two carcinoma metastases were cut into fragments of 0.5 mm diameter, and placed in agar overlay tissue culture. The tumour specimens formed spheroids which were co-cultured with cell aggregates or fragments from fetal

O. Engebraaten; R. Bjerkvig; M. Lund-Johansen; K. Wester; P.-H. Pedersen; S. Mork; E.-O. Backlund; O. D. Laerum

1990-01-01

110

Extracellular vesicles as prospective carriers of oncogenic protein signatures in adult and paediatric brain tumours.  

PubMed

Extracellular vesicles (EVs), including exosomes, act as biological effectors and as carriers of oncogenic signatures in human cancer. The molecular composition and accessibility of EVs in biofluids open unprecedented diagnostic opportunities in malignancies where tumour tissue is difficult to sample, especially in primary and metastatic brain tumours. The ongoing genetic discovery of driver mutations defines the ever increasing numbers of distinct molecular subtypes of brain tumours (orphan diseases), a complexity that may soon be translated into alterations in functional proteins and their oncogenic networks. This may likely be extended to real time changes engendered by the disease progression, tumour heterogeneity, inter-individual variations and therapeutic responses. Meeting these challenges through EV analysis is dependent on technological progress in such areas as generation of mutation- and phospho-specific antibodies, antibody array platforms, nanotechnology, microfluidics, NMR spectroscopy, MS and MRM approaches of quantitative proteomics, which should not be underestimated. Still, vesiculation emerges as a unique process that could be harnessed for the benefit of more individualised patient care. PMID:23505048

Garnier, Delphine; Jabado, Nada; Rak, Janusz

2013-04-20

111

Diffusion tensor imaging demonstrates deviation of fibres in normal appearing white matter adjacent to a brain tumour  

Microsoft Academic Search

the objective was to study fibre orientation in the cerebral white matter of a patient with a brain tumour using diffusion tensor imaging (DTI). A patient with a mild left hemiparesis and a tumour in the right frontal lobe and 20 healthy volunteers were scanned with a DTI sequence. The scans were spatially normalised and the fibre orientation in the

U C Wieshmann; M R Symms; G J M Parker; C A Clark; L Lemieux; G J Barker; S D Shorvon

2000-01-01

112

Classification brain MR images through a fuzzy multiwavelets based GMM and probabilistic neural networks  

Microsoft Academic Search

In this paper, a new approach for classification of brain tissues into White Matter, Gray Matter, Cerebral Spinal Fluid, Glial Matter, Connective and MS lesion in multiple sclerosis is introduced. This work considers fuzzy multiwavelets, Gaussian Mixture Model (GMM) and Weighted Probabilistic Neural Networks (WPNN) for the classification of the brain tissues. Multiwavelet packet transformation is employed on brain MR

S. Ramakrishnan

2011-01-01

113

Childhood brain tumour risk and its association with wireless phones: a commentary  

PubMed Central

Case-control studies on adults point to an increased risk of brain tumours (glioma and acoustic neuroma) associated with the long-term use of mobile phones. Recently, the first study on mobile phone use and the risk of brain tumours in children and adolescents, CEFALO, was published. It has been claimed that this relatively small study yielded reassuring results of no increased risk. We do not agree. We consider that the data contain several indications of increased risk, despite low exposure, short latency period, and limitations in the study design, analyses and interpretation. The information certainly cannot be used as reassuring evidence against an association, for reasons that we discuss in this commentary.

2011-01-01

114

Childhood brain tumour risk and its association with wireless phones: a commentary.  

PubMed

Case-control studies on adults point to an increased risk of brain tumours (glioma and acoustic neuroma) associated with the long-term use of mobile phones. Recently, the first study on mobile phone use and the risk of brain tumours in children and adolescents, CEFALO, was published. It has been claimed that this relatively small study yielded reassuring results of no increased risk. We do not agree. We consider that the data contain several indications of increased risk, despite low exposure, short latency period, and limitations in the study design, analyses and interpretation. The information certainly cannot be used as reassuring evidence against an association, for reasons that we discuss in this commentary. PMID:22182218

Söderqvist, Fredrik; Carlberg, Michael; Hansson Mild, Kjell; Hardell, Lennart

2011-12-19

115

Radiobiological and Magnetic Resonance Studies of Combined Radiation and Cisplatin Therapy in the 9l Rat Brain Tumour Model.  

NASA Astrophysics Data System (ADS)

The prognosis for adult patients with primary malignant brain tumours is poor. Radiation therapy is a standard adjutant to surgery in the treatment of these patients, but is rarely curative. The extreme radio-resistance of primary malignant brain tumours is due in part to their enhanced capacity for repair of potentially lethal radiation damage. The chemotherapeutic agent cisplatin has been shown to inhibit repair of radiation damage. Therefore combined cisplatin and radiation therapy could be a key to enhanced therapeutic gain in the treatment of primary malignant brain tumours. In this project, the 9L rat brain tumour model was used to investigate combined radiation and cisplatin treatments. In vitro experiments showed the 9L cell line to be highly radioresistant and, like human malignant brain tumour cells, to have a high capacity for repair of potentially lethal radiation damage. These cells were found to be moderately resistant to the cytotoxic effects of cisplatin. In vitro exposure to cisplatin at clinically relevant concentrations caused inhibition of potentially lethal damage repair, with the amount of inhibition depending on cisplatin dose and treatment sequence. Magnetic resonance imaging (MRI) was used to monitor the effects of combined radiation and cisplatin treatments of implanted intracranial 9L tumours in rats. A new technique for implanting experimental tumours was developed which resulted in more uniform tumour growth, and methods for radiation and cisplatin treatment of experimental intracranial tumours were developed and evaluated. Non-invasive measurements of tumour size using MRI were found to correlate well with measurements made from histological sections. Intraperitoneal administration of gadolinium contrast agent immediately before T1-weighted MRI was shown to be the most accurate and reliable method for MRI measurement of intracranial tumour size. The capability of MRI to provide early indications of radiation injury to normal brain tissue was evaluated in the rat, and MRI changes were found to occur on average 130 days following partial brain irradiation. Combined radiation and cisplatin treatments of intracranial 9L tumours did not result in tumour regression observable by MRI, despite histopathological evidence of increased tumour necrosis compared with radiation or cisplatin treatments alone.

Wilkins, David E.

1993-01-01

116

What is new in the surgical approach for malignant brain tumours  

Microsoft Academic Search

Summary  Maligant gliomas occur at an incidence from 2 to 10\\/100,000 (Japan vs. Sweden) constituting up 50% of all patients suffering\\u000a from brain tumours. Despite all therapeutic approaches the median survival for glioblastomas is 15 months and for anaplastic\\u000a gliomas Grade III are 30 months. Surgery is the first step in the therapeutic cascade of the patients. There is still debate

H. Kostron

2009-01-01

117

Incremental Gaussian Discriminant Analysis based on Graybill and Deal weighted combination of estimators for brain tumour diagnosis.  

PubMed

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 when new data are collected. In this study, an incremental learning algorithm for Gaussian Discriminant Analysis (iGDA) based on the Graybill and Deal weighted combination of estimators is introduced. Each time a new set of data becomes available, a new estimation is carried out and a combination with a previous estimation is performed. iGDA does not require access to the previously used data and is able to include new classes that were not in the original analysis, thus allowing the customization of the models to the distribution of data at a particular clinical center. An evaluation using five benchmark databases has been used to evaluate the behaviour of the iGDA algorithm in terms of stability-plasticity, class inclusion and order effect. Finally, the iGDA algorithm has been applied to automatic brain tumour classification with magnetic resonance spectroscopy, and compared with two state-of-the-art incremental algorithms. The empirical results obtained show the ability of the algorithm to learn in an incremental fashion, improving the performance of the models when new information is available, and converging in the course of time. Furthermore, the algorithm shows a negligible instance and concept order effect, avoiding the bias that such effects could introduce. PMID:21377545

Tortajada, Salvador; Fuster-Garcia, Elies; Vicente, Javier; Wesseling, Pieter; Howe, Franklyn A; Julià-Sapé, Margarida; Candiota, Ana-Paula; Monleón, Daniel; Moreno-Torres, Angel; Pujol, Jesús; Griffiths, John R; Wright, Alan; Peet, Andrew C; Martínez-Bisbal, M Carmen; Celda, Bernardo; Arús, Carles; Robles, Montserrat; García-Gómez, Juan Miguel

2011-03-04

118

Development and piloting of a brain tumour-specific question prompt list.  

PubMed

The objective of this research was to develop a question prompt list aimed at increasing question asking and reducing the unmet information needs of adults with primary brain tumours, and to pilot the question prompt list to determine its suitability for the intended population. Thematic analysis of existing resources was used to create a draft which was refined via interviews with 12 brain tumour patients and six relatives, readability testing and review by health professionals. A non-randomised before-after pilot study with 20 brain tumour patients was used to assess the acceptability and usefulness of the question prompt list, compared with a 'standard brochure', and the feasibility of evaluation strategies. The question prompt list developed covered seven main topics (diagnosis, prognosis, symptoms and changes, treatment, support, after treatment finishes and the health professional team). Pilot study participants provided with the question prompt list agreed that it was helpful (7/7), contained questions that were useful to them (7/7) and prompted them to ask their medical oncologist questions (5/7). The question prompt list is acceptable to patients and contains questions relevant to them. Research is now needed to assess its effectiveness in increasing question asking and reducing unmet information needs. PMID:22309311

Langbecker, D; Janda, M; Yates, P

2012-02-06

119

Brain tumour imaging with carbon-11 choline: comparison with FDG PET and gadolinium-enhanced MR imaging  

Microsoft Academic Search

The purpose of this study was to assess the clinical potential of methyl-11C-choline (11C-choline) in the diagnosis of brain tumours. To this end, the results of 11C-choline positron emission tomography (PET) in 22 patients suspected of having brain tumours were compared with the findings of contrast-enhanced magnetic resonance (MR) imaging and fluorine-18 fluorodeoxyglucose PET. A histopathological diagnosis was made for

Toshiyuki Ohtani; Hideyuki Kurihara; Shogo Ishiuchi; Nobuhito Saito; Noboru Oriuchi; Tomio Inoue; Tomio Sasaki

2001-01-01

120

Clinical role of technetium-99m sestamibi single-photon emission tomography in evaluating pretreated patients with brain tumours  

Microsoft Academic Search

One of the main problems regarding the follow-up of patients with brain tumours treated with radiotherapy is the distinction between radiation necrosis and tumour relapse. In many cases computed tomography (CT) scan is unable to distinguish between the two. We assessed the usefulness of brain single-photon emission tomography (SPET) with technetium-99m-sestamibi in cases where CT scan was not conclusive. The

Lorenzo Maffioli; Massimo Gasparini; Arturo Chiti; Alberto Gramaglia; Valeria Mongioj; Annalisa Pozzi; Emilio Bombardieri

1996-01-01

121

Topology-preserving tissue classification of magnetic resonance brain images.  

PubMed

This paper presents a new framework for multiple object segmentation in medical images that respects the topological properties and relationships of structures as given by a template. The technique, known as topology-preserving, anatomy-driven segmentation (TOADS), combines advantages of statistical tissue classification, topology-preserving fast marching methods, and image registration to enforce object-level relationships with little constraint over the geometry. When applied to the problem of brain segmentation, it directly provides a cortical surface with spherical topology while segmenting the main cerebral structures. Validation on simulated and real images characterises the performance of the algorithm with regard to noise, inhomogeneities, and anatomical variations. PMID:17427736

Bazin, Pierre-Louis; Pham, Dzung L

2007-04-01

122

Use of mobile phones and risk of brain tumours: update of Danish cohort study  

PubMed Central

Objective To investigate the risk of tumours in the central nervous system among Danish mobile phone subscribers. Design Nationwide cohort study. Setting Denmark. Participants All Danes aged ?30 and born in Denmark after 1925, subdivided into subscribers and non-subscribers of mobile phones before 1995. Main outcome measures Risk of tumours of the central nervous system, identified from the complete Danish Cancer Register. Sex specific incidence rate ratios estimated with log linear Poisson regression models adjusted for age, calendar period, education, and disposable income. Results 358?403 subscription holders accrued 3.8 million person years. In the follow-up period 1990-2007, there were 10?729 cases of tumours of the central nervous system. The risk of such tumours was close to unity for both men and women. When restricted to individuals with the longest mobile phone use—that is, ?13 years of subscription—the incidence rate ratio was 1.03 (95% confidence interval 0.83 to 1.27) in men and 0.91 (0.41 to 2.04) in women. Among those with subscriptions of ?10 years, ratios were 1.04 (0.85 to 1.26) in men and 1.04 (0.56 to 1.95) in women for glioma and 0.90 (0.57 to 1.42) in men and 0.93 (0.46 to 1.87) in women for meningioma. There was no indication of dose-response relation either by years since first subscription for a mobile phone or by anatomical location of the tumour—that is, in regions of the brain closest to where the handset is usually held to the head. Conclusions In this update of a large nationwide cohort study of mobile phone use, there were no increased risks of tumours of the central nervous system, providing little evidence for a causal association.

2011-01-01

123

VIPARnd - GeVero® tool in planning of TPS scheduled brain tumour radiotherapy  

NASA Astrophysics Data System (ADS)

In this paper, VIPARnd - GeVero® tool is presented for the first time in an application to a brain tumour radiotherapy. Whereas usefulness of VIPARnd polymer gel in various radiotherapy techniques has recently been confirmed, GeVero® software for calculation of MRI polymer gel data and comparison with TPS dose distribution simulation is now examined. The results demonstrate satisfactory agreement between polymer gel dosimetry-MRI and TPS dose distributions and prove helpfulness of the software and VIPARnd polymer gel in radiotherapy dosimetry. It is also believed that the software facilitates data processing and therefore should be of further support in po-gel dosimetry studies.

Kozicki, Marek; Maras, Piotr; Rybka, Krzysztof; Biega?ski, Tadeusz

2009-05-01

124

Brain tissue segmentation in 4D CT using voxel classification  

NASA Astrophysics Data System (ADS)

A method is proposed to segment anatomical regions of the brain from 4D computer tomography (CT) patient data. The method consists of a three step voxel classification scheme, each step focusing on structures that are increasingly difficult to segment. The first step classifies air and bone, the second step classifies vessels and the third step classifies white matter, gray matter and cerebrospinal fluid. As features the time averaged intensity value and the temporal intensity change value were used. In each step, a k-Nearest-Neighbor classifier was used to classify the voxels. Training data was obtained by placing regions of interest in reconstructed 3D image data. The method has been applied to ten 4D CT cerebral patient data. A leave-one-out experiment showed consistent and accurate segmentation results.

van den Boom, R.; Oei, M. T. H.; Lafebre, S.; Oostveen, L. J.; Meijer, F. J. A.; Steens, S. C. A.; Prokop, M.; van Ginneken, B.; Manniesing, R.

2012-02-01

125

Childhood brain tumours and use of mobile phones: comparison of a case-control study with incidence data  

PubMed Central

The first case–control study on mobile phone use and brain tumour risk among children and adolescents (CEFALO study) has recently been published. In a commentary published in Environmental Health, Söderqvist and colleagues argued that CEFALO suggests an increased brain tumour risk in relation to wireless phone use. In this article, we respond and show why consistency checks of case–control study results with observed time trends of incidence rates are essential, given the well described limitations of case–control studies and the steep increase of mobile phone use among children and adolescents during the last decade. There is no plausible explanation of how a notably increased risk from use of wireless phones would correspond to the relatively stable incidence time trends for brain tumours among children and adolescents observed in the Nordic countries. Nevertheless, an increased risk restricted to heavy mobile phone use, to very early life exposure, or to rare subtypes of brain tumours may be compatible with stable incidence trends at this time and thus further monitoring of childhood brain tumour incidence rate time trends is warranted.

2012-01-01

126

Multidisciplinary care of gastrointestinal stromal tumour: A review and a proposal for a pre-treatment classification.  

PubMed

The introduction of receptor tyrosine kinase inhibitors (TKIs) has revolutionized the management of gastrointestinal stromal tumour (GIST). Strong evidence supports the use of imatinib as first-line treatment in metastatic or unresectable tumours and its efficacy in the post-operative adjuvant setting has been confirmed by phase III trials. There are a number of reports concerning the administration of imatinib in the pre-operative setting, however, the heterogeneity of the terminology used and the indications for pre-operative treatment make it difficult to determine the true value of pre-operative imatinib. Larger studies, or a phase III trial could be helpful but patient accrual and standardization of care could be difficult. We propose a pre-treatment classification of GIST in order to facilitate the comparison and collection of data from different institutions, and overcome the difficulties related to accrual. Moreover, in the current era of multidisciplinary treatment of GIST, an appropriate classification is mandatory to properly design clinical trials and plan stage-adapted treatment. PMID:24063969

Cananzi, F C M; Judson, I; Lorenzi, B; Benson, C; Mudan, S

2013-09-07

127

Low temperature magnetic analysis in the identification of iron compounds from human brain tumour tissue  

NASA Astrophysics Data System (ADS)

In the brain, iron plays an important role, but also is potentially toxic if iron metabolism is disrupted. Excess iron accumulation in the brain has been shown to be associated with neurodegenerative diseases. However, identification of iron compounds in human tissue is difficult because concentrations are very low. Three types of magnetic methods were used to characterize iron compounds in tumour tissue from epileptic patients. Isothermal Remanent Magnetization (IRM) was measured at 77 K and 300 K and reveals a low-coercivity phase with the properties of magnetite or maghemite. Induced magnetization was measured between 2 K and 300 K after cooling in zero-field and in a 50 mT field. These curves reveal an average blocking temperature of 11 K, which is compatible with ferritin. The results of this study show that the combination of different magnetic methods provides a useful and sensitive tool for the characterisation of magnetic iron compounds in human tissue.

Brem, F.; Hirt, A. M.; Simon, C.; Wieser, H.-G.; Dobson, J.

2005-01-01

128

Nuclear microprobe analysis of the selective boron uptake obtained with BPA in brain tumour tissue  

NASA Astrophysics Data System (ADS)

The tumour selective ability of the boron compound boronophenylalanine (BPA), today used in Boron Neutron Capture Therapy in Sweden, has been investigated with the Lund Nuclear Microprobe. The tumour to tissue ratio of the boron concentration, as well as the location of boron within the cells, is critical for the efficiency of the therapy. It is desirable that the boron is accumulated as close as possible to the cell nucleus, since the alpha particles produced in the 10B(n,?)7Li reaction only have a range of about 10 microns, i.e. a cell diameter. The nuclear reaction 11B(p,?)2?, which has an especially high cross-section (300 mb) for 660 keV protons, has been used to analyse brain tissue from BPA-injected rats. Previous studies on other boron compounds have shown significant background problems when the alpha particles are detected in the backward direction. By a specially designed set-up, alpha particles in the forward and backward direction are detected simultaneously, and only the coincidences between the two directions are considered to be true boron events. In this way we could achieve excellent background suppression. The analysis shows that BPA indeed is tumour selective. Quantifications show a boron abundance of 150+/-20 ng/cm2 in normal tissue and 567+/-70 ng/cm2 in tumour tissue. If the rat is fed with l-dopa before the injection of BPA the uptake increases 3-4 times. The boron is homogeneously distributed in the cellular structure and no specific intracellular accumulation has been shown.

Wegdén, M.; Kristiansson, P.; Ceberg, C.; Munck Af Rosenschöld, P.; Auzelyte, V.; Elfman, M.; Malmqvist, K. G.; Nilsson, C.; Pallon, J.; Shariff, A.

2004-06-01

129

Ongoing transitions: the impact of a malignant brain tumour on patient and family.  

PubMed

Although primary malignant brain tumours represent only 1.4% of all cancers, it is considered one of the most devastating types of cancers in adults. From the time of diagnosis, the patient and family embark on a "roller coaster" ride of uncertainty, fear and hope. Despite improved medical outcomes, patients often experience severe functional impairment, as well as behavioural and cognitive dysfunction. Subsequently, they suffer from greater dependency and hopelessness than other cancer patients. The family caregivers are faced with multiple demands such as taking on new roles within the family and caring for their loved one while grieving the loss of the person they knew. The role of the nurse is to support the patient and the family throughout the illness trajectory, identify and promote their strengths and mobilize the necessary resources to facilitate patient and family coping. The purpose of this paper is to present, via a detailed case study, the impact of a malignant brain tumour on the patient and the family. The nursing strategies used to help them make the necessary transitions throughout the illness trajectory are discussed. PMID:17682686

Khalili, Yasmin

2007-01-01

130

Estimating progression-free survival in paediatric brain tumour patients when some progression statuses are unknown  

PubMed Central

Summary In oncology, progression-free survival time, which is defined as the minimum of the times to disease progression or death, often is used to characterize treatment and covariate effects. We are motivated by the desire to estimate the progression time distribution on the basis of data from 780 paediatric patients with choroid plexus tumours, which are a rare brain cancer where disease progression always precedes death. In retrospective data on 674 patients, the times to death or censoring were recorded but progression times were missing. In a prospective study of 106 patients, both times were recorded but there were only 20 non-censored progression times and 10 non-censored survival times. Consequently, estimating the progression time distribution is complicated by the problems that, for most of the patients, either the survival time is known but the progression time is not known, or the survival time is right censored and it is not known whether the patient’s disease progressed before censoring. For data with these missingness structures, we formulate a family of Bayesian parametric likelihoods and present methods for estimating the progression time distribution. The underlying idea is that estimating the association between the time to progression and subsequent survival time from patients having complete data provides a basis for utilizing covariates and partial event time data of other patients to infer their missing progression times. We illustrate the methodology by analysing the brain tumour data, and we also present a simulation study.

Yuan, Ying; Thall, Peter F.; Wolff, Johannes E.

2012-01-01

131

Position-dependent expression of GADD45? in rat brain tumours  

Microsoft Academic Search

Although the complex and multifactorial process of tumour growth has been extensively studied for decades, our understanding\\u000a of the fundamental relationship between tumour growth dynamics and genetic expression profile remains incomplete. Recent studies\\u000a of tumour dynamics indicate that gene expression in solid tumours would depend on the distance from the centre of the tumour.\\u000a Since tumour proliferative activity is mainly

Antonio Brú; Carlos del Fresno; Alessandra Soares-Schanoski; Sonia Albertos; Isabel Brú; Amelia Porres; Eduardo Rollán-Landeras; Ana Dopazo; David Casero; Vanesa Gómez-Piña; Lourdes García; Francisco Arnalich; Rebeca Alvarez; Alexandro Rodríguez-Rojas; Pablo Fuentes-Prior; Eduardo López-Collazo

2007-01-01

132

Brain tumours in childhood in Bombay: I: Histopathology showing changing patterns; II: Tissue culture with light and electronmicroscopy, stressing ingestion & degradation of bacteria by glial cells in vitro  

Microsoft Academic Search

The pathological pattern of 86 braintumours’ in childhood during the years 1981–85 (out of a total of 586 for all ages), showed a higher proportion of neoplasms and a much lower of tuberculomas compared to the preceding three decades. A large number of histologically unusual cases was revealed. Through tissue culture of brain tumours we carried out morphological, histochemical

Darab K. Dastur; Sharda R. Kankonkar; Daya K. Manghani; Tanaaz H. Vakil; Usha P. Dave; Sanat N. Bhagwati

1989-01-01

133

Quality and readability of information materials for people with brain tumours and their families.  

PubMed

Written information is commonly used to inform patients about their disease and treatment but must be evidence-based and understandable to be useful. This study assessed the quality of the content and the readability of information brochures for people affected by brain tumours. We randomly selected 18 publicly available brochures. Brochures were assessed by criteria to assess the quality of content using the DISCERN instrument. Readability was tested using three commonly used formulas, which yield the reading grade level required to comprehend the brochure (sixth grade level recommended). The mean overall DISCERN score was 3.17 out of a maximum of 5 (moderate quality); only one achieved a rating greater than 4 (high quality). Only one brochure met the sixth grade readability criteria. Although brochures may have accurate content, few satisfied all of the recommended criteria to evaluate their content. Existing brochures need to be critically reviewed and simplified and consumer-focused brochures, produced. PMID:22918795

Langbecker, Danette; Janda, Monika

2012-12-01

134

TOPICAL REVIEW: A review of classification algorithms for EEG-based brain computer interfaces  

Microsoft Academic Search

In this paper we review classification algorithms used to design brain-computer interface (BCI) systems based on electroencephalography (EEG). We briefly present the commonly employed algorithms and describe their critical properties. Based on the literature, we compare them in terms of performance and provide guidelines to choose the suitable classification algorithm(s) for a specific BCI.

F. Lotte; M. Congedo; A. Lécuyer; F. Lamarche; B. Arnaldi

2007-01-01

135

Brain tumour imaging with PET: a comparison between [18F]fluorodopa and [11C]methionine.  

PubMed

Imaging of amino acid transport in brain tumours is more sensitive than fluorine-18 2-fluoro-deoxyglucose positron emission tomography (PET). The most frequently used tracer in this field is carbon-11 methionine (MET), which is unavailable for PET centres without a cyclotron because of its short half-life. The purpose of this study was to evaluate the performance of 3,4-dihydroxy-6-[(18)F]fluoro-phenylalanine (FDOPA) in this setting, in comparison with MET. Twenty patients with known supratentorial brain lesions were referred for PET scans with FDOPA and MET. The diagnoses were 18 primary brain tumours, one metastasis and one non-neoplastic cerebral lesion. All 20 patients underwent PET with FDOPA (100 MBq, 20 min p.i.), and 19 of them also had PET scans with MET (800 MBq, 20 min p.i.). In all but one patient a histological diagnosis was available. In 15 subjects, histology was known from previous surgical interventions; in five of these patients, as well as in four previously untreated patients, histology was obtained after PET. In one untreated patient, confirmation of PET was possible solely by correlation with MRI; a histological diagnosis became available 10 months later. MET and FDOPA images matched in all patients and showed all lesions as hot spots with higher uptake than in the contralateral brain. Standardised uptake value ratios, tumour/contralateral side (mean+/-SD), were 2.05+/-0.91 for MET and 2.04+/-0.53 for FDOPA (NS). The benign lesion, which biopsy revealed to be a focal demyelination, was false positive, showing increased uptake of MET and FDOPA. We conclude that FDOPA is accurate as a surrogate for MET in imaging amino acid transport in malignant cerebral lesions for the purpose of visualisation of vital tumour tissue. It combines the good physical properties of (18)F with the pharmacological properties of MET and might therefore be a valuable PET radiopharmaceutical in brain tumour imaging. PMID:14579097

Becherer, Alexander; Karanikas, Georgios; Szabó, Monica; Zettinig, Georg; Asenbaum, Susanne; Marosi, Christine; Henk, Christine; Wunderbaldinger, Patrick; Czech, Thomas; Wadsak, Wolfgang; Kletter, Kurt

2003-07-23

136

Diagnostic assessment of brain tumours and non-neoplastic brain disorders in vivo using proton nuclear magnetic resonance spectroscopy and artificial neural networks  

Microsoft Academic Search

Purpose\\u000a : Experiments were carried out to assess the potential of artificial neural network (ANN) analysis in the differential diagnosis\\u000a of brain tumours (low- and high-grade gliomas) from non-neoplastic focal brain lesions (tuberculomas and abscesses), using\\u000a proton magnetic resonance spectroscopy (1H MRS) as input data. Methods\\u000a : Single-voxel stimulated echo acquisition mode (STEAM) (echo time of 20?ms) spectra were acquired

Harish Poptani; Jouni Kaartinen; Rakesh K. Gupta; Matthias Niemitz; Yrjö Hiltunen; Risto A. Kauppinen

1999-01-01

137

The INTERPRET Decision-Support System version 3.0 for evaluation of Magnetic Resonance Spectroscopy data from human brain tumours and other abnormal brain masses  

Microsoft Academic Search

BACKGROUND: Proton Magnetic Resonance (MR) Spectroscopy (MRS) is a widely available technique for those clinical centres equipped with MR scanners. Unlike the rest of MR-based techniques, MRS yields not images but spectra of metabolites in the tissues. In pathological situations, the MRS profile changes and this has been particularly described for brain tumours. However, radiologists are frequently not familiar to

Alexander Pérez-Ruiz; Margarida Julià-Sapé; Guillem Mercadal; Iván Olier; Carles Majós; Carles Arús

2010-01-01

138

The oxidation states and chemical environments of iron and zinc as potential indicators of brain tumour malignancy grade - preliminary results.  

PubMed

Despite the enormous advances in medicine, brain tumours are still among the lesser-known types of tumours and carry the worst prognoses. Transition metals are believed to play an essential role in carcinogenesis. The aim of this study was to determine differences in the average oxidation state and trends in the changes in the chemical environment of iron and zinc contained in healthy and neoplastic tissues of the human brain. For this purpose, X-ray Absorption Spectroscopy was used, which enables the study of disordered matter. The samples were taken intraoperatively and then immediately frozen to slow down chemical processes. Sixteen tumour samples with various malignancy grades were studied as well as one control sample. For each sample four to eight spectra were recorded, with a shift between them not greater than 0.2 eV. In all of the samples, iron occurred in compounds with both Fe(2+) and Fe(3+). However, the ratio of Fe(ii) to Fe(iii) content in the tissue visibly increased with the tumour malignancy grade. The change in the oxidation state of iron did not correlate with the hypoxia level of the tissues. Analysis of EXAFS spectra of zinc atoms showed that the chemical environment of zinc atoms differed with the tumour malignancy grade. Additionally, cryogenic conditions were found to produce positive results in studies of biological samples, whose form under such conditions is close to their native state, without preparation-caused artefacts. PMID:23945910

Wandzilak, Aleksandra; Czyzycki, Mateusz; Wrobel, Pawel; Szczerbowska-Boruchowska, Magdalena; Radwanska, Edyta; Adamek, Dariusz; Lankosz, Marek

2013-10-23

139

Sparse representation-based classification scheme for motor imagery-based brain-computer interface systems  

NASA Astrophysics Data System (ADS)

Motor imagery (MI)-based brain-computer interface systems (BCIs) normally use a powerful spatial filtering and classification method to maximize their performance. The common spatial pattern (CSP) algorithm is a widely used spatial filtering method for MI-based BCIs. In this work, we propose a new sparse representation-based classification (SRC) scheme for MI-based BCI applications. Sensorimotor rhythms are extracted from electroencephalograms and used for classification. The proposed SRC method utilizes the frequency band power and CSP algorithm to extract features for classification. We analyzed the performance of the new method using experimental datasets. The results showed that the SRC scheme provides highly accurate classification results, which were better than those obtained using the well-known linear discriminant analysis classification method. The enhancement of the proposed method in terms of the classification accuracy was verified using cross-validation and a statistical paired t-test (p < 0.001).

Shin, Younghak; Lee, Seungchan; Lee, Junho; Lee, Heung-No

2012-10-01

140

A Weighted K-means Algorithm applied to Brain Tissue Classification  

Microsoft Academic Search

Tissue classification in Magnetic Resonance (MR) brain images is an important issue in the analysis of several brain dementias. This paper presents a modification of the classical K-means algorithm taking into account the number of times specific features appear in an image, employing, for that purpose, a weighted mean to calculate the centroid of every cluster. Pattern Recognition techniques allow

Guillermo N. Abras; Virginia L. Ballarin

2005-01-01

141

Brain Stem Gliomas: A Classification System Based on Magnetic Resonance Imaging  

Microsoft Academic Search

MR scans of 87 pediatric patients with brain stem gliomas were retrospectively reviewed to develop a new classification scheme based on MR imaging. The scheme that has been developed utilizes primarily T2-weighted images, as these most accurately show tumor extent. Tumors are characterized as to location of origin, focality, direction and extent of tumor growth, degree of brain stem enlargement,

A. J. Barkovich; J. Krischer; L. A. Kun; R. J. Packer; R. A. Zimmerman; C. R. Freeman; W. M. Wara; L. Albright; J. C. Allen

1991-01-01

142

Motor Imagery Signal Classification for a Four State Brain Machine Interface  

Microsoft Academic Search

Motor imagery classification provides an important basis for designing Brain Machine Interfaces (BMI). A BMI captures and decodes brain EEG signals and transforms human thought into actions. The ability of an individual to control his EEG through imaginary mental tasks enables him to control devices through the BMI. This paper presents a method to design a four state BMI using

S. Yaacob; A. H. Adom; R Nagarajan

2008-01-01

143

Quality of life in patients with stable disease after surgery, radiotherapy, and chemotherapy for malignant brain tumour  

PubMed Central

OBJECTIVES—to evaluate quality of life in patients with malignant brain tumour with stable disease after combined treatments in comparison to patients with other chronic neurological conditions, and to explore the relation of quality of life to clinical, pathological, affective and cognitive factors.?METHODS—fifty seven patients who were stable after surgery, radiotherapy and chemotherapy and 24 controls with spastic paraparesis, peripheral neuropathies, myasthenia, ataxia, Parkinson's disease, or multiple sclerosis, were studied. Patients were evaluated by functional living index-cancer, Karnofsky performance status, activity of daily living, self-rating depression scale, state-trait anxiety inventory, and tests for cognitive abilities.?RESULTS—separate Mann-Whitney test comparisons did not show any difference in measures of health related quality of life (functional living index-cancer), autonomy in daily life (activity of daily living), or mood between tumour and control patients, although the first had slower mental speed and worse attention. Seventy three per cent of patients with brain tumour and 58% of the control patients continued or resumed previous work activity. Quality of life was significantly associated with depression, state anxiety, and performance status in the patients with brain tumour, whereas in control patients, state anxiety was the only factor related to quality of life.?CONCLUSIONS—after intensive multimodality treatments, selected patients with brain tumour with stable disease may have satisfactory quality of life that may be not worse than in patients with other chronic neurological illnesses. During the period of stable disease, depressed mood, possibly a reaction to impaired physical and cognitive performance, seems to play a major role in determining quality of life.??

Giovagnoli, A.

1999-01-01

144

“Now we have to cope with the rest of our lives”. Existential issues related to parenting a child surviving a brain tumour  

Microsoft Academic Search

Aim  The aim of the paper was to explore the existential issues expressed by parents of children who had been treated for brain\\u000a tumours.\\u000a \\u000a \\u000a \\u000a \\u000a Background  A brain tumour in childhood is an event that triggers acute traumatic stress and it has long-term consequences for the child\\u000a as well as for the parents. Due to advanced treatment techniques, more children survive brain tumours

Ulla Forinder; Annika Lindahl Norberg

2010-01-01

145

Meta-analysis of long-term mobile phone use and the association with brain tumours.  

PubMed

We evaluated long-term use of mobile phones and the risk for brain tumours in case-control studies published so far on this issue. We identified ten studies on glioma and meta-analysis yielded OR = 0.9, 95% CI = 0.8-1.1. Latency period of > or =10-years gave OR = 1.2, 95% CI = 0.8-1.9 based on six studies, for ipsilateral use (same side as tumour) OR = 2.0, 95% CI = 1.2-3.4 (four studies), but contralateral use did not increase the risk significantly, OR = 1.1, 95% CI = 0.6-2.0. Meta-analysis of nine studies on acoustic neuroma gave OR = 0.9, 95% CI = 0.7-1.1 increasing to OR = 1.3, 95% CI = 0.6-2.8 using > or =10-years latency period (four studies). Ipsilateral use gave OR = 2.4, 95% CI = 1.1-5.3 and contra-lateral OR = 1.2, 95% CI = 0.7-2.2 in the > or =10-years latency period group (three studies). Seven studies gave results for meningioma yielding overall OR = 0.8, 95% CI = 0.7-0.99. Using > or =10-years latency period OR = 1.3, 95% CI = 0.9-1.8 was calculated (four studies) increasing to OR = 1.7, 95% CI = 0.99-3.1 for ipsilateral use and OR = 1.0, 95% CI = 0.3-3.1 for contralateral use (two studies). We conclude that this meta-analysis gave a consistent pattern of an association between mobile phone use and ipsilateral glioma and acoustic neuroma using > or =10-years latency period. PMID:18425337

Hardell, Lennart; Carlberg, Michael; Söderqvist, Fredrik; Hansson Mild, Kjell

2008-05-01

146

NG2 expression regulates vascular morphology and function in human brain tumours  

Microsoft Academic Search

Tumour angiogenesis is a tightly regulated process involving cross-talk between tumour cells and the host tissue. The underlying mechanisms that regulate such interactions remain largely unknown. NG2 is a transmembrane proteoglycan whose presence on transformed cells has been demonstrated to increase proliferation in vitro and angiogenesis in vivo. To study the effects of NG2 during tumour growth and progression, we

C. Brekke; A. Lundervold; P. Ø. Enger; C. Brekken; E. Stålsett; T. B. Pedersen; O. Haraldseth; P. G. Krüger; R. Bjerkvig; M. Chekenya

2006-01-01

147

Real-time classification of activated brain areas for fMRI-based human-brain-interfaces  

NASA Astrophysics Data System (ADS)

Functional MR imaging (fMRI) enables to detect different activated brain areas according to the performed tasks. However, data are usually evaluated after the experiment, which prohibits intra-experiment optimization or more sophisticated applications such as biofeedback experiments. Using a human-brain-interface (HBI), subjects are able to communicate with external programs, e.g. to navigate through virtual scenes, or to experience and modify their own brain activation. These applications require the real-time analysis and classification of activated brain areas. Our paper presents first results of different strategies for real-time pattern analysis and classification realized within a flexible experiment control system that enables the volunteers to move through a 3D virtual scene in real-time using finger tapping tasks, and alternatively only thought-based tasks.

Moench, Tobias; Hollmann, Maurice; Grzeschik, Ramona; Mueller, Charles; Luetzkendorf, Ralf; Baecke, Sebastian; Luchtmann, Michael; Wagegg, Daniela; Bernarding, Johannes

2008-04-01

148

Perioperative thromboprophylaxis in patients with craniotomy for brain tumours: a systematic review.  

PubMed

Venous thromboembolism (VTE) events are frequent in neurooncological patients in perioperative period thus increasing mortality and morbidity. The role of prophylaxis has not yet been established with certainty, and in various neurosurgery and intensive care units the practice is inconsistent. A better definition of the risk/cost/benefit ratio of the various methods, both mechanical (intermittent pneumatic compression-IPC, graduated compression stockings-GCS) and pharmacological (unfractionated heparin-UFH or low molecular weight heparin-LMWH), is warranted. We aim to define the optimal prophylactic treatment in the perioperative period in neurooncological patients. A systematic review of the literature was performed in Medline, Embase and Cochrane Library. Thirteen randomized controlled trials (RCTs) were identified, in which physical methods (IPC or GCS) and/or drugs (UFH or LMWHs) were evaluated in perioperative prophylaxis of neurological patients, mostly with brain cancer not treated with anticoagulants for other diseases. The analysis was conducted on a total of 1,932 randomized patients of whom 1,558 had brain tumours. Overall data show a trend of reduction of VTE in patients treated with mechanical methods (IPC or GCS) that should be initiated preoperatively and continued until discharge or longer in case of persistence of risk factors. The addition of enoxaparin starting the day after surgery, significantly reduces clinically manifest VTE, despite an increase in major bleeding events. Further studies are needed to delineate the types of patients with an increase of VTE risk and risk/benefits ratio of physical and pharmacological treatments in the perioperative period. PMID:23543244

Salmaggi, Andrea; Simonetti, Giorgia; Trevisan, Elisa; Beecher, Deirdre; Carapella, Carmine Maria; DiMeco, Francesco; Conti, Laura; Pace, Andrea; Filippini, Graziella

2013-03-30

149

Differences in target outline delineation from CT scans of brain tumours using different methods and different observers  

Microsoft Academic Search

Purpose: To assess errors resulting from manual transfer of contour information for three-dimensional (3-D) target reconstruction, and to determine variations in target volume delineation of brain tumours by different radiation oncologists.Materials and methods: Images of 18 patients with intracranial astrocytomas were used for retrospective treatment planning by five radiation oncologists. In this study, the target outline was delineated on sequential

Masashi Yamamoto; Yasushi Nagata; Kaoru Okajima; Takashi Ishigaki; Rumi Murata; Takashi Mizowaki; Masaki Kokubo; Masahiro Hiraoka

1999-01-01

150

The monoclonal antibody Ki67 as a marker for proliferating cells in stereotactic biopsies of brain tumours  

Microsoft Academic Search

Summary The monoclonal antibody Ki-67 has been tested as a marker of proliferating cells in 52 stereotactic brain tumour biopsies. The antibody reacts with a nuclear protein expressed in G1,S, G2n and Mphases of the cell cycle. Using the immunoperoxidase technique on squash preparations the percentage of Ki-67 positive cells was determined as a fraction of the total number of

C. B. Ostertag; B. Volk; T. Shibata; P. Burger; P. Kleihues

1987-01-01

151

Respiratory Deleted in Malignant Brain Tumours 1 (DMBT1) levels increase during lung maturation and infection.  

PubMed

Deleted in Malignant Brain Tumours 1 (DMBT1) is a secreted scavenger receptor cysteine-rich protein that binds and aggregates various bacteria and viruses in vitro. Studies in adults have shown that DMBT1 is expressed mainly by mucosal epithelia and glands, in particular within the respiratory tract, and plays a role in innate immune defence. We hypothesized that respiratory DMBT1 levels may be influenced by various developmental and clinical factors such as maturity, age and bacterial infection. DMBT1 levels were studied in 205 tracheal aspirate samples of 82 ventilated preterm and full-term infants by enzyme-linked immunosorbent assay. Possible effects of various clinical parameters were tested by multiple regression analysis. DMBT1 levels increased significantly with lung maturity (P < 0.0001 for both gestational and postnatal age) and in small-for-gestational-age infants (P = 0.0179). An increase of respiratory DMBT1 levels was detected in neonatal infections (P < 0.0001). These results were supported by Western blotting. Immunohistochemical analyses of archived newborn lung sections (n = 17) demonstrated high concentrations of DMBT1 in lungs of neonates with bacterial infections. Our data show that preterm infants are able to up-regulate DMBT1 in infection as an unspecific immune reaction. PMID:17991292

Müller, H; End, C; Weiss, C; Renner, M; Bhandiwad, A; Helmke, B M; Gassler, N; Hafner, M; Poustka, A; Mollenhauer, J; Poeschl, J

2007-11-07

152

The influence of mineralising radionecrosis on the dose distribution in interstitial radiation therapy of brain tumours.  

PubMed

The influences of radionecroses arising during interstitial radiation of brain tumours with 125I, 192Ir or 198Au on dose distribution was investigated using Monte Carlo methods. The necroses have a higher density than normal tissue due to radiation-induced changes in tissue composition as well as mineral deposits. They can have a diameter of up to 1 cm around the single seeds. The higher density and changed chemical composition compared to homogeneous normal tissue leads to increased absorption of radiation around the necroses which results in a lower dose rate in the surrounding tissue. It is shown that the formation of necroses during treatment with higher energy radiation such as 192Ir (340 keV) or 198Au (400 keV) may be neglected during therapy planning as the dose rate is affected by less than 2%. If low energy radiation, e.g. 125I (28 keV) is used, the dose rate can be reduced by more than 30%. In this case the influence of the necroses on dose distribution, at least for permanent 125I implantation, may not be negligible. PMID:1410584

Herbold, G; Hartmann, G H; Lorenz, W J

1992-09-01

153

Fitness to drive in patients with brain tumours: the influence of mandatory reporting legislation on radiation oncologists in Canada  

PubMed Central

Background Certain jurisdictions in Canada legally require that physicians report unfit drivers. Physician attitudes and patterns of practice have yet to be evaluated in Canada for patients with brain tumours. Methods We conducted a survey of 97 radiation oncologists, eliciting demographics, knowledge of reporting laws, and attitudes on reporting guidelines for unfit drivers. Eight scenarios with varying disability levels were presented to determine the likelihood of a patient being reported as unfit to drive. Statistical comparisons were made using the Fisher exact test. Results Of physicians approached, 99% responded, and 97 physicians participated. Most respondents (87%) felt that laws in their province governing the reporting of medically unfit drivers were unclear. Of the responding physicians, 23 (24%) were unable to correctly identify whether their province had mandatory reporting legislation. Physicians from provinces without mandatory reporting legislation were significantly less likely to consider reporting patients to provincial authorities (p = 0.001), and for all clinical scenarios, the likelihood of reporting significantly depended on the physician’s provincial legal obligations. Conclusions The presence of provincial legislation is of primary importance in determining whether physicians will report brain tumour patients to drivers’ licensing authorities. In Canada, clear guidelines have to be developed to help in the assessment of whether brain tumour patients should drive.

Louie, A.V.; D'Souza, D.P.; Palma, D.A.; Bauman, G.S.; Lock, M.; Fisher, B.; Patil, N.; Rodrigues, G.B.

2012-01-01

154

Pooled analysis of two case–control studies on use of cellular and cordless telephones and the risk for malignant brain tumours diagnosed in 1997–2003  

Microsoft Academic Search

Objectives: To study the use of cellular and cordless telephones and the risk for malignant brain tumours. Methods: Two case–control studies on malignant brain tumours diagnosed during 1997–2003 included answers from 905 (90%) cases and 2,162 (89%) controls aged 20–80 years. We present pooled analysis of the results in the two studies. Results: Cumulative lifetime use for >2,000 h yielded for analogue

Lennart Hardell; Michael Carlberg; Kjell Hansson Mild

2006-01-01

155

Automated segmentation and classification of multispectral magnetic resonance images of brain using artificial neural networks  

Microsoft Academic Search

Presents a fully automated process for segmentation and classification of multispectral magnetic resonance (MR) images. This hybrid neural network method uses a Kohonen self-organizing neural network for segmentation and a multilayer backpropagation neural network for classification. To separate different tissue types, this process uses the standard T1-, T2-, and PD-weighted MR images acquired in clinical examinations. Volumetric measurements of brain

Wilburn E. Reddick; John O. Glass; Edwin N. Cook; T. David Elkin; Russell J. Deaton

1997-01-01

156

FUZZY ARTMAP CLASSIFICATION FOR MOTOR IMAGINARY BASED BRAIN COMPUTER INTERFACE  

Microsoft Academic Search

The rapid advancement of Brain Machine Interface (BMI) or Brain Computer Interface (BCI) research over the recent years is concentrated to the development of new technologies which adopts the easiest procedures since the expected beneficiaries are of disabled in nature. Most of the locked-in patients possess strong mental ability in terms of imagining and thinking but they are extremely unable

Vickneswaran Jeyabalan; Andrews Samraj; Loo Chu Kiong

157

Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study  

PubMed Central

Summary Background Although CT scans are very useful clinically, potential cancer risks exist from associated ionising radiation, in particular for children who are more radiosensitive than adults. We aimed to assess the excess risk of leukaemia and brain tumours after CT scans in a cohort of children and young adults. Methods In our retrospective cohort study, we included patients without previous cancer diagnoses who were first examined with CT in National Health Service (NHS) centres in England, Wales, or Scotland (Great Britain) between 1985 and 2002, when they were younger than 22 years of age. We obtained data for cancer incidence, mortality, and loss to follow-up from the NHS Central Registry from Jan 1, 1985, to Dec 31, 2008. We estimated absorbed brain and red bone marrow doses per CT scan in mGy and assessed excess incidence of leukaemia and brain tumours cancer with Poisson relative risk models. To avoid inclusion of CT scans related to cancer diagnosis, follow-up for leukaemia began 2 years after the first CT and for brain tumours 5 years after the first CT. Findings During follow-up, 74 of 178?604 patients were diagnosed with leukaemia and 135 of 176?587 patients were diagnosed with brain tumours. We noted a positive association between radiation dose from CT scans and leukaemia (excess relative risk [ERR] per mGy 0·036, 95% CI 0·005–0·120; p=0·0097) and brain tumours (0·023, 0·010–0·049; p<0·0001). Compared with patients who received a dose of less than 5 mGy, the relative risk of leukaemia for patients who received a cumulative dose of at least 30 mGy (mean dose 51·13 mGy) was 3·18 (95% CI 1·46–6·94) and the relative risk of brain cancer for patients who received a cumulative dose of 50–74 mGy (mean dose 60·42 mGy) was 2·82 (1·33–6·03). Interpretation Use of CT scans in children to deliver cumulative doses of about 50 mGy might almost triple the risk of leukaemia and doses of about 60 mGy might triple the risk of brain cancer. Because these cancers are relatively rare, the cumulative absolute risks are small: in the 10 years after the first scan for patients younger than 10 years, one excess case of leukaemia and one excess case of brain tumour per 10?000 head CT scans is estimated to occur. Nevertheless, although clinical benefits should outweigh the small absolute risks, radiation doses from CT scans ought to be kept as low as possible and alternative procedures, which do not involve ionising radiation, should be considered if appropriate. Funding US National Cancer Institute and UK Department of Health.

Pearce, Mark S; Salotti, Jane A; Little, Mark P; McHugh, Kieran; Lee, Choonsik; Kim, Kwang Pyo; Howe, Nicola L; Ronckers, Cecile M; Rajaraman, Preetha; Craft, Alan W; Parker, Louise; de Gonzalez, Amy Berrington

2012-01-01

158

Brain Activity-Based Image Classification From Rapid Serial Visual Presentation  

Microsoft Academic Search

We report the design and performance of a brain-computer interface (BCI) system for real-time single-trial binary classification of viewed images based on participant-specific dynamic brain response signatures in high-density (128-channel) electroencephalographic (EEG) data acquired during a rapid serial visual presentation (RSVP) task. Image clips were selected from a broad area image and presented in rapid succession (12\\/s) in 4.1-s bursts.

Nima Bigdely-Shamlo; Andrey Vankov; Rey R. Ramirez; Scott Makeig

2008-01-01

159

Transient mutism and speech disorders after posterior fossa surgery in children with brain tumours  

Microsoft Academic Search

Summary Four patients aged 5 to 9 years with large tumours located in the posterior fossa (PNET, ependymoma or astrocytoma) are presented. Patients received standard neuropsychological assessments, including speech evaluation, prior to surgery. Following tumour resection, these 4 children developed transient mutism or different types of speech and cognitive disorders, associated with behavioural disturbances.

A. Kingma; J. J. A. Mooij; J. D. M. Metzemaekers; J. A. Leeuw

1994-01-01

160

Potential of anti-cancer therapy based on anti-miR-155 oligonucleotides in glioma and brain tumours.  

PubMed

MicroRNAs are aberrantly expressed in many cancers and can exert tumour-suppressive or oncogenic functions. As oncomirs promote growth of cancer cells and support survival during chemotherapy, thus microRNA-silencing therapies could be a valuable approach to be associated with anticancer drugs and chemotherapy treatments. miR-155 microRNA was found overexpressed in different types of cancer, such as leukaemias (PML, B-cell lymphomas), lung cancer and glioblastoma. GABA-A receptor downregulation was found correlated with glioma grading, with decreasing levels associated with higher grade of malignancies. A relationship between knock-down of miR-155 and re-expression of GABRA 1 protein in vivo was recently individuated. This finding has implication on the effectiveness of RNA-silencing approaches against miR-155 with the scope to control proliferation and signalling pathways regulated by GABA-A receptor. Applying microRNAs for treatment of brain tumours poses several problems, and fields to be solved are mainly the passage of the brain-blood barrier and the targeted delivery to specific cell types. Glioblastoma multiforme cells bud off microvesicles that deliver cytoplasmic contents to nearby cells. Thus, the exploitation of these mechanisms to deliver antagomir therapeutics targeting microvescicles in the brain could take the lead in the near future in the treatment for brain cancers in substitution of invasive surgical intervention. PMID:22834637

Poltronieri, Palmiro; D'Urso, Pietro I; Mezzolla, Valeria; D'Urso, Oscar F

2013-01-01

161

PPAR? agonists regulate the expression of stemness and differentiation genes in brain tumour stem cells  

PubMed Central

Background: Brain tumour stem cells (BTSCs) are a small population of cancer cells that exhibit self-renewal, multi-drug resistance, and recurrence properties. We have shown earlier that peroxisome proliferator-activated receptor gamma (PPAR?) agonists inhibit the expansion of BTSCs in T98G and U87MG glioma. In this study, we analysed the influence of PPAR? agonists on the expression of stemness and differentiation genes in BTSCs. Methods: The BTSCs were isolated from T98G and DB29 glioma cells, and cultured in neurobasal medium with epidermal growth factor+basic fibroblast growth factor. Proliferation was measured by WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2?H-5-tetrazolio]-1,3-benzene disulphonate) and 3H thymidine uptake assays, and gene expression was analysed by quantitative reverse--transcription PCR and Taqman array. The expression of CD133, SRY box 2, and nanog homeobox (Nanog) was also evaluated by western blotting, immunostaining, and flow cytometry. Results: We found that PPAR? agonists, ciglitazone and 15-deoxy-?12,14-ProstaglandinJ2, inhibited cell viability and proliferation of T98G- and DB29-BTSCs. The PPAR? agonists reduced the expansion of CD133+ BTSCs and altered the expression of stemness and differentiation genes. They also inhibited Sox2 while enhancing Nanog expression in BTSCs. Conclusion: These findings highlight that PPAR? agonists inhibit BTSC proliferation in association with altered expression of Sox2, Nanog, and other stemness genes. Therefore, targeting stemness genes in BTSCs could be a novel strategy in the treatment of glioblastoma.

Pestereva, E; Kanakasabai, S; Bright, J J

2012-01-01

162

EEG Classification using Radial Basis PSO Neural Network for Brain Machine Interfaces  

Microsoft Academic Search

Brain machine interfaces use the cognitive abilities of patients with neuromuscular disorders to restore communication and motor functions. At present, only EEG and related methods, which have relatively short time constants, can function in most environments, they also require relatively simple and inexpensive equipment. In this paper we propose a mental task classification algorithm using a particle swarm optimization (PSO)

M. P. Paulraj; C. R. Hema; R. Nagarajan; S. Yaacob; A. H. Adorn

2007-01-01

163

Pattern Classification of Large-Scale Functional Brain Networks: Identification of Informative Neuroimaging Markers for Epilepsy  

PubMed Central

The accurate prediction of general neuropsychiatric disorders, on an individual basis, using resting-state functional magnetic resonance imaging (fMRI) is a challenging task of great clinical significance. Despite the progress to chart the differences between the healthy controls and patients at the group level, the pattern classification of functional brain networks across individuals is still less developed. In this paper we identify two novel neuroimaging measures that prove to be strongly predictive neuroimaging markers in pattern classification between healthy controls and general epileptic patients. These measures characterize two important aspects of the functional brain network in a quantitative manner: (i) coordinated operation among spatially distributed brain regions, and (ii) the asymmetry of bilaterally homologous brain regions, in terms of their global patterns of functional connectivity. This second measure offers a unique understanding of brain asymmetry at the network level, and, to the best of our knowledge, has not been previously used in pattern classification of functional brain networks. Using modern pattern-recognition approaches like sparse regression and support vector machine, we have achieved a cross-validated classification accuracy of 83.9% (specificity: 82.5%; sensitivity: 85%) across individuals from a large dataset consisting of 180 healthy controls and epileptic patients. We identified significantly changed functional pathways and subnetworks in epileptic patients that underlie the pathophysiological mechanism of the impaired cognitive functions. Specifically, we find that the asymmetry of brain operation for epileptic patients is markedly enhanced in temporal lobe and limbic system, in comparison with healthy individuals. The present study indicates that with specifically designed informative neuroimaging markers, resting-state fMRI can serve as a most promising tool for clinical diagnosis, and also shed light onto the physiology behind complex neuropsychiatric disorders. The systematic approaches we present here are expected to have wider applications in general neuropsychiatric disorders.

Zhang, ZhiQiang; Lu, WenLian; Lu, GuangMing; Feng, Jianfeng

2012-01-01

164

Pharmaco-thermodynamics of deuterium-induced oedema in living rat brain via 1H2O MRI: implications for boron neutron capture therapy of malignant brain tumours  

NASA Astrophysics Data System (ADS)

In addition to its common usage as a tracer in metabolic and physiological studies, deuterium possesses anti-tumoural activity and confers protection against ?-irradiation. A more recent interest in deuterium emanates from the search for alternatives capable of improving neutron penetrance whilst reducing healthy tissue radiation dose deposition in boron neutron capture therapy of malignant brain tumours. Despite this potential clinical application, deuterium induces brain oedema, which is detrimental to neutron capture therapy. In this study, five adult male rats were titrated with deuterated drinking water while brain oedema was monitored via water proton magnetic resonance imaging. This report concludes that deuterium, as well as deuterium-induced brain oedema, possesses a uniform brain bio-distribution. At a steady-state blood fluid deuteration value of 16%, when the deuterium isotope fraction in drinking water was 25%, a mean oedematous volume change of 9 ± 2% (p-value <0.001) was observed in the rat brain—this may account for neurological and behavioural abnormalities found in mammals drinking highly deuterated water. In addition to characterizing the pharmaco-thermodynamics of deuterium-induced oedema, this report also estimates the impact of oedema on thermal neutron enhancement and effective dose reduction factors using simple linear transport calculations. While body fluid deuteration enhances thermal neutron flux penetrance and reduces dose deposition, oedema has the opposite effect because it increases the volume of interest, e.g., the brain volume. Thermal neutron enhancement and effective dose reduction factors could be reduced by as much as ~10% in the presence of a 9% water volume increase (oedema). All three authors have contributed equally to this work.

Medina, Daniel C.; Li, Xin; Springer, Charles S., Jr.

2005-05-01

165

Kinetic analysis of novel mono- and multivalent VHH-fragments and their application for molecular imaging of brain tumours  

PubMed Central

Background and purpose: The overexpression of epidermal growth factor receptor (EGFR) and its mutated variant EGFRvIII occurs in 50% of glioblastoma multiforme. We developed antibody fragments against EGFR/EGFRvIII for molecular imaging and/or therapeutic targeting applications. Experimental approach: An anti–EGFR/EGFRvIII llama single-domain antibody (EG2) and two higher valency format constructs, bivalent EG2-hFc and pentavalent V2C-EG2 sdAbs, were analysed in vitro for their binding affinities using surface plasmon resonance and cell binding studies, and in vivo using pharmacokinetic, biodistribution, optical imaging and fluorescent microscopy studies. Key results: Kinetic binding analyses by surface plasmon resonance revealed intrinsic affinities of 55 nM and 97 nM for the monovalent EG2 to immobilized extracellular domains of EGFR and EGFRvIII, respectively, and a 10- to 600-fold increases in apparent affinities for the multivalent binders, V2C-EG2 and EG2-hFc, respectively. In vivo pharmacokinetic and biodistribution studies in mice revealed plasma half-lives for EG2, V2C-EG2 and EG2-hFc of 41 min, 80 min and 12.5 h, respectively, as well as a significantly higher retention of EG2-hFc compared to the other two constructs in EGFR/EGFRvIII-expressing orthotopic brain tumours, resulting in the highest signal in the tumour region in optical imaging studies. Time domain volumetric optical imaging fusion with high-resolution micro-computed tomography of microvascular brain network confirmed EG2-hFc selective accumulation/retention in anatomically defined tumour regions. Conclusions: Single domain antibodies can be optimized for molecular imaging applications by methods that improve their apparent affinity and prolong plasma half-life and, at the same time, preserve their ability to penetrate tumour parenchyma.

Iqbal, U; Trojahn, U; Albaghdadi, H; Zhang, J; O'Connor-McCourt, M; Stanimirovic, D; Tomanek, B; Sutherland, G; Abulrob, A

2010-01-01

166

Real-time support vector classification and feedback of multiple emotional brain states.  

PubMed

An important question that confronts current research in affective neuroscience as well as in the treatment of emotional disorders is whether it is possible to determine the emotional state of a person based on the measurement of brain activity alone. Here, we first show that an online support vector machine (SVM) can be built to recognize two discrete emotional states, such as happiness and disgust from fMRI signals, in healthy individuals instructed to recall emotionally salient episodes from their lives. We report the first application of real-time head motion correction, spatial smoothing and feature selection based on a new method called Effect mapping. The classifier also showed robust prediction rates in decoding three discrete emotional states (happiness, disgust and sadness) in an extended group of participants. Subjective reports ascertained that participants performed emotion imagery and that the online classifier decoded emotions and not arbitrary states of the brain. Offline whole brain classification as well as region-of-interest classification in 24 brain areas previously implicated in emotion processing revealed that the frontal cortex was critically involved in emotion induction by imagery. We also demonstrate an fMRI-BCI based on real-time classification of BOLD signals from multiple brain regions, for each repetition time (TR) of scanning, providing visual feedback of emotional states to the participant for potential applications in the clinical treatment of dysfunctional affect. PMID:20692351

Sitaram, Ranganatha; Lee, Sangkyun; Ruiz, Sergio; Rana, Mohit; Veit, Ralf; Birbaumer, Niels

2010-08-06

167

Adaptive classification on brain-computer interfaces using reinforcement signals.  

PubMed

We introduce a probabilistic model that combines a classifier with an extra reinforcement signal (RS) encoding the probability of an erroneous feedback being delivered by the classifier. This representation computes the class probabilities given the task related features and the reinforcement signal. Using expectation maximization (EM) to estimate the parameter values under such a model shows that some existing adaptive classifiers are particular cases of such an EM algorithm. Further, we present a new algorithm for adaptive classification, which we call constrained means adaptive classifier, and show using EEG data and simulated RS that this classifier is able to significantly outperform state-of-the-art adaptive classifiers. PMID:22845827

Llera, A; Gómez, V; Kappen, H J

2012-07-30

168

Diagnostic benefits of presurgical fMRI in patients with brain tumours in the primary sensorimotor cortex  

Microsoft Academic Search

Objectives  Reliable imaging of eloquent tumour-adjacent brain areas is necessary for planning function-preserving neurosurgery. This\\u000a study evaluates the potential diagnostic benefits of presurgical functional magnetic resonance imaging (fMRI) in comparison\\u000a to a detailed analysis of morphological MRI data.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Standardised preoperative functional and structural neuroimaging was performed on 77 patients with rolandic mass lesions at\\u000a 1.5 Tesla. The central region of both

Martina Wengenroth; M. Blatow; J. Guenther; M. Akbar; V. M. Tronnier; C. Stippich

2011-01-01

169

The Risk of Haemorrhage after Image Guided Stereotactic Biopsy of Intra-Axial Brain Tumours – A Prospective Study  

Microsoft Academic Search

Summary  ?Objective. To analyze prospectively the frequency and the risk of symptomatic and asymptomatic haemorrhage after image guided stereotactic\\u000a biopsy of intra-axial brain tumours.\\u000a \\u000a ?Methods. The study was conducted within a time frame of 24 months (April 1998–April 2000). 326 patients (150 males, 176 females; mean\\u000a age 56.8 years) were included and 345 computerized tomography (CT)-guided stereotactic biopsies were performed\\/supervised\\u000a by

F. W. Kreth; A. Muacevic; R. Medele; K. Bise; T. Meyer; H.-J. Reulen

2001-01-01

170

CLASSIFICATION  

NSDL National Science Digital Library

Students will learn about classification Go into the Carnivorous Plant site and find 5 facts about carnivorous plants and write them in your science journal. Carnivorous Plants Using the animal classification site, click on the animals shown and write information about 2 of them in your journal. animal classification Use the animal diversity web page and write down ...

Kirby, Ms.

2009-09-23

171

Recursive Feature Elimination for Brain Tumor Classification using Desorption Electrospray Ionization Mass Spectrometry Imaging  

PubMed Central

The metabolism and composition of lipids is of increasing interest for understanding and detecting disease processes. Lipid signatures of tumor type and grade have been demonstrated using magnetic resonance spectroscopy. Clinical management and ultimate prognosis of brain tumors depend largely on the tumor type, subtype, and grade. Mass spectrometry, a well-known analytical technique used to identify molecules in a given sample based on their mass, can significantly improve the problem of tumor type classification. This work focuses on the problem of identifying lipid features to use as input for classification. Feature selection could result in improvements in classifier performance, discovery of biomarkers, improved data interpretation, and patient treatment.

Gholami, Behnood; Norton, Isaiah; Tannenbaum, Allen R.; Agar, Nathalie Y. R.

2013-01-01

172

Health related quality of life in the first year after diagnosis in children with brain tumours compared with matched healthy controls; a prospective longitudinal study  

Microsoft Academic Search

This paper compares parent- and self-report health-related quality of life (HRQL) in children aged 2–16 years with brain tumours, one, six and twelve months after diagnosis with matched normal controls. HRQL was assessed using the PedsQL generic core scales. 37 tumour patients and 42 controls were included in analysis of parent-report, and 27 patients and 31 controls in self-report HRQL.

Anthony Penn; Stephen P. Lowis; Linda P. Hunt; Robert I. Shortman; Michael C. G. Stevens; Renee L. McCarter; Andrew L. Curran; Peta M. Sharples

2008-01-01

173

Sensitivity and specificity of thallium-201 single-photon emission tomography in the functional detection and differential diagnosis of brain tumours  

Microsoft Academic Search

The aim of this retrospective study was to assess the contribution of thallium-201 single-photon emission tomography (SPET) in the detection and differential diagnosis of brain tumours. In 90 patients 201Tl SPET was performed because of clinical or radiological suspicion of tumoral invasion, completed by technetium-99m hexamethylpropylene amine oxime and 99mTc-sestamibi SPET in some patients. For all tumours, diagnosis was based

R. A. Dierckx; J. J. Martin; A. Dobbeleir; R. Crols; I. Neetens; P. P. Deyn

1994-01-01

174

Vidarabin-monophosphate, BCNU, VM26--an in vitro comparative study of active agents in the treatment of malignant human brain tumours.  

PubMed Central

BCNU (carmustine), VM26 (teniposide) and ARA-A5'P (vidarabin-monophosphate) were compared in their activity against 30 cell lines of primary (N = 21) and metastatic (N = 9) human brain tumours, which were characterized in tissue culture by cytochemical, immunological and cytogenetic criteria. In vivo achievable concentration-time products c X t were correlated with in vitro pharmacokinetic data in order to evaluate in vitro drug sensitivity at relevant exposure doses. A microcytotoxicity assay was employed to screen for drug toxicity in individual tumour cell lines. Following drug exposure and 5 to 8 population doubling times of untreated controls, RNA-synthesis - as a parameter of cell metabolism and proliferation - was determined by incorporation of [5,6-3H]-uridine into cellular RNA (liquid scintillation counting protocol). The cytotoxic effect of each drug on individual cell lines was expressed in terms of a sensitivity index (SI); by these means effects of different drugs on individual tumour cell lines could be compared. Mean sensitivity indices of ARA-A5'P, BCNU and VM26 for primary brain tumour cell lines were 0.59, 0.82 and 0.54. ARA-A5'P and VM26 had almost similar activities against brain tumour cell lines, whereas BCNU was significantly (P less than 0.001) less active. High grade gliomas were less sensitive to all three agents than low grade and infratentorial gliomas. ARA-A5'P was also able to effectively reduce colony formation in brain tumour cell lines. A cross-resistance of ARA-A5'P to either BCNU or VM26 could not be observed. Clearly, ARA-A5'P is an effective drug in treatment of brain tumour cells in vitro.

Bogdahn, U.; Zapf, J.; Weber, H.; Dunisch, G.; Lobering, H. G.; Martin, R.; Mertens, H. G.

1987-01-01

175

Pooled analysis of two Swedish case-control studies on the use of mobile and cordless telephones and the risk of brain tumours diagnosed during 1997-2003.  

PubMed

Here we present the pooled analysis of 2 case-control studies on the association of brain tumours with mobile phone use. Use of analogue cellular phones increased the risk for acoustic neuroma by 5%, 95% confidence interval (CI) = 2-9% per 100 hrs of use. The risk increased for astrocytoma grade III-IV with latency period with highest estimates using >10-year time period from first use of these phone types. The risk increased per one year of use of analogue phones by 10%, 95% CI = 6-14%, digital phones by 11%, 95% CI = 6-16%, and cordless phones by 8%, 95% CI = 5-12%. For all studied phone types OR for brain tumours, mainly acoustic neuroma and malignant brain tumours, increased with latency period, especially for astrocytoma grade III-IV. PMID:17362659

Mild, Kjell Hansson; Hardell, Lennart; Carlberg, Michael

2007-01-01

176

Length of hospital stay and contributing variables in supratentorial craniotomy patients with brain tumour: a pre-care map study.  

PubMed

The study included 70 patients admitted to Neurosurgical ICU (NICU) with the diagnosis of Supratentorial Craniotomy for Brain Tumour. These patients were followed throughout their hospitalization in NICU, to the ward and until discharge from hospital. The purposes of the study were (a) to indicated the NICU and floor length of stay (LOS) in this group of patients, prior to the use of care map and compare it to a developed care map, and (b) to identify the variables that contribute toe overall prolonged hospital LOS. The findings indicated that, prior to the use of care map, 68.8% of Supratentorial Craniotomy Patients with Brain Tumour had an ICU LOS of one day. However, only 38.6% of these patients were discharged from hospital within the care map indicated 5 day post ICU, floor LOS. The findings also showed that the overall hospital LOS, in 71.4% of the patients, was over 7 days, as indicated on the developed care cap. Several variables such as patient complications, consults, rehab/placement, patient falls and additional diagnostic tests contributed to the overall pronged hospital LOS. Thus, by monitoring these variables with the use of a care map, may produce measurements to evaluate cost effectiveness, and allow health care professionals to provide more effective and quality patient care. PMID:7857865

Sarkissian, S

1994-06-01

177

Classification of Alzheimer's disease using regional saliency maps from brain MR volumes  

NASA Astrophysics Data System (ADS)

Accurate diagnosis of Alzheimer's disease (AD) from structural Magnetic Resonance (MR) images is difficult due to the complex alteration of patterns in brain anatomy that could indicate the presence or absence of the pathology. Currently, an effective approach that allows to interpret the disease in terms of global and local changes is not available in the clinical practice. In this paper, we propose an approach for classification of brain MR images, based on finding pathology-related patterns through the identification of regional structural changes. The approach combines a probabilistic Latent Semantic Analysis (pLSA) technique, which allows to identify image regions through latent topics inferred from the brain MR slices, with a bottom-up Graph-Based Visual Saliency (GBVS) model, which calculates maps of relevant information per region. Regional saliency maps are finally combined into a single map on each slice, obtaining a master saliency map of each brain volume. The proposed approach includes a one-to-one comparison of the saliency maps which feeds a Support Vector Machine (SVM) classifier, to group test subjects into normal or probable AD subjects. A set of 156 brain MR images from healthy (76) and pathological (80) subjects, splitted into a training set (10 non-demented and 10 demented subjects) and one testing set (136 subjects), was used to evaluate the performance of the proposed approach. Preliminary results show that the proposed method reaches a maximum classification accuracy of 87.21%.

Pulido, Andrea; Rueda, Andrea; Romero, Eduardo

2013-02-01

178

Long-term outcome in patients with germ cell tumours treated with POMB/ACE chemotherapy: comparison of commonly used classification systems of good and poor prognosis.  

PubMed Central

We analysed outcome in 206 consecutive male patients treated for metastatic non-seminomatous germ cell tumour (NSGCT) of testicular or extragonadal origin treated with the POMB/ACE (cisplatin, vincristine, methotrexate, bleomycin, actinomycin D, cyclophosphamide, etoposide) regimen after division into prognostic groups by commonly used clinical classification systems and definitions of adverse prognosis. The adverse prognostic groups of all classification systems and definitions examined showed similar, but only moderate, sensitivity (71-81%) and specificity (52-56%) in predicting death. A simple definition of poor prognosis based on raised initial levels of serum tumour markers alpha fetoprotein (aFP) and human chorionic gonadotrophin (hCG) proved at least as useful (sensitivity 80%, specificity 55%) as other more complicated systems in predicting failure to achieve long-term survival. Comparison of survival between ultra-high dose cisplatin-based combination chemotherapy and patients treated with POMB/ACE shows no advantage from this more toxic approach. This suggests that good results in adverse prognosis patients can be achieved using conventional dose regimens administered intensively.

Hitchins, R. N.; Newlands, E. S.; Smith, D. B.; Begent, R. H.; Rustin, G. J.; Bagshawe, K. D.

1989-01-01

179

Verbal Fluency Indicators of Malingering in Traumatic Brain Injury: Classification Accuracy in Known Groups  

Microsoft Academic Search

A known-groups design was used to determine the classification accuracy of verbal fluency variables in detecting Malingered Neurocognitive Dysfunction (MND) in traumatic brain injury (TBI). Participants were 204 TBI and 488 general clinical patients. The Slick et al. (1999) criteria were used to classify the TBI patients into non-MND and MND groups. An educationally corrected FAS Total Correct word T-score

Kelly L. Curtis; Laura K. Thompson; Kevin W. Greve; Kevin J. Bianchini

2008-01-01

180

Motor imagery classification by means of source analysis for brain computer interface applications  

Microsoft Academic Search

We report a pilot study of performing classification of motor imagery for brain-computer interface applications, by means of source analysis of scalp-recorded EEGs. Independent component analysis (ICA) was used as a spatio-temporal filter extracting signal components relevant to left or right motor imagery (MI) tasks. Source analysis methods including equivalent dipole analysis and cortical current density imaging were applied to

Lei Qin; Lei Ding; Bin He

2004-01-01

181

Multi-kernel SVM based classification for brain tumor segmentation of MRI multi-sequence  

Microsoft Academic Search

In this paper, the multi-kernel SVM (Support Vector Machine) classification, integrated with a fusion process, is proposed to segment brain tumor from multi-sequence MRI images (T2, PD, FLAIR). The objective is to quantify the evolution of a tumor during a therapeutic treatment. As the procedure develops, a manual learning process about the tumor is carried out just on the first

Nan Zhang; Su Ruan; Stéphane Lebonvallet; Qingmin Liao; Yuemin Zhu

2009-01-01

182

Automatic and adaptive classification of electroencephalographic signals for brain computer interfaces.  

PubMed

Extracting knowledge from electroencephalographic (EEG) signals has become an increasingly important research area in biomedical engineering. In addition to its clinical diagnostic purposes, in recent years there have been many efforts to develop brain computer interface (BCI) systems, which allow users to control external devices only by using their brain activity. Once the EEG signals have been acquired, it is necessary to use appropriate feature extraction and classification methods adapted to the user in order to improve the performance of the BCI system and, also, to make its design stage easier. This work introduces a novel fast adaptive BCI system for automatic feature extraction and classification of EEG signals. The proposed system efficiently combines several well-known feature extraction procedures and automatically chooses the most useful features for performing the classification task. Three different feature extraction techniques are applied: power spectral density, Hjorth parameters and autoregressive modelling. The most relevant features for linear discrimination are selected using a fast and robust wrapper methodology. The proposed method is evaluated using EEG signals from nine subjects during motor imagery tasks. Obtained experimental results show its advantages over the state-of-the-art methods, especially in terms of classification accuracy and computational cost. PMID:23117792

Rodríguez-Bermúdez, Germán; García-Laencina, Pedro J

2012-11-02

183

In vitro inhibition of human malignant brain tumour cell line proliferation by anti-urokinase-type plasminogen activator monoclonal antibodies.  

PubMed Central

A brain tumour-associated marker, urokinase (UK), was investigated using rabbit anti-UK polyclonal and murine anti-UK monoclonal antibodies, which were prepared by immunization with low molecular weight UK (LMW-UK) and high molecular weight urokinase (HMW-UK) synthetic peptide respectively. The polyclonal antibody cross-reacted with both LMW-UK and HMW-UK, whereas the murine MAbs were specific for HMW-UK. These immunological probes were used to study urokinase in glioma extracts, tissues, sera and cell lines that had been prepared from primary cultures of freshly dissected gliomas. Radioimmunoassays showed that glioma extracts had much higher level (5- to 44-fold) of UK than normal human brain extracts. This result was confirmed by immunoblotting of electrophoresis gels of glioma and human brain extracts. Immunohistochemical study using anti-UK MAb demonstrated much higher levels of UK in glioma tissue than normal brain tissue. Immunohistochemical study using anti-UK MAbs localized UK on the cell surface of glioma cells. Anti-UK MAbs inhibited the proliferation of AA cell lines and GB cell lines (50% to > 90%) and exerted minor effects (< or = 20%) on normal human liver, intestine and lymphocyte cell lines. Taken together, these results suggest that anti-UK MAbs may have therapeutic potential for human gliomas and cancer metastasis. Images Figure 2 Figure 3

Abaza, M. S.; Shaban, F. A.; Narayan, R. K.; Atassi, M. Z.

1998-01-01

184

Identification of primary tumors of brain metastases by SIMCA classification of IR spectroscopic images.  

PubMed

Brain metastases are secondary intracranial lesions which occur more frequently than primary brain tumors. The four most abundant types of brain metastasis originate from primary tumors of lung cancer, colorectal cancer, breast cancer and renal cell carcinoma. As metastatic cells contain the molecular information of the primary tissue cells and IR spectroscopy probes the molecular fingerprint of cells, IR spectroscopy based methods constitute a new approach to determine the origin of brain metastases. IR spectroscopic images of 4 by 4 mm2 tissue areas were recorded in transmission mode by a FTIR imaging spectrometer coupled to a focal plane array detector. Unsupervised cluster analysis revealed variances within each cryosection. Selected clusters of five IR images with known diagnoses trained a supervised classification model based on the algorithm soft independent modeling of class analogies (SIMCA). This model was applied to distinguish normal brain tissue from brain metastases and to identify the primary tumor of brain metastases in 15 independent IR images. All specimens were assigned to the correct tissue class. This proof-of-concept study demonstrates that IR spectroscopy can complement established methods such as histopathology or immunohistochemistry for diagnosis. PMID:16787638

Krafft, Christoph; Shapoval, Larysa; Sobottka, Stephan B; Geiger, Kathrin D; Schackert, Gabriele; Salzer, Reiner

2006-05-19

185

Feature Extraction from Subband Brain Signals and Its Classification  

NASA Astrophysics Data System (ADS)

This paper considers both the non-stationarity as well as independence/uncorrelated criteria along with the asymmetry ratio over the electroencephalogram (EEG) signals and proposes a hybrid approach of the signal preprocessing methods before the feature extraction. A filter bank approach of the discrete wavelet transform (DWT) is used to exploit the non-stationary characteristics of the EEG signals and it decomposes the raw EEG signals into the subbands of different center frequencies called as rhythm. A post processing of the selected subband by the AMUSE algorithm (a second order statistics based ICA/BSS algorithm) provides the separating matrix for each class of the movement imagery. In the subband domain the orthogonality as well as orthonormality criteria over the whitening matrix and separating matrix do not come respectively. The human brain has an asymmetrical structure. It has been observed that the ratio between the norms of the left and right class separating matrices should be different for better discrimination between these two classes. The alpha/beta band asymmetry ratio between the separating matrices of the left and right classes will provide the condition to select an appropriate multiplier. So we modify the estimated separating matrix by an appropriate multiplier in order to get the required asymmetry and extend the AMUSE algorithm in the subband domain. The desired subband is further subjected to the updated separating matrix to extract subband sub-components from each class. The extracted subband sub-components sources are further subjected to the feature extraction (power spectral density) step followed by the linear discriminant analysis (LDA).

Mukul, Manoj Kumar; Matsuno, Fumitoshi

186

Which method of posttraumatic stress disorder classification best predicts psychosocial function in children with traumatic brain injury?  

Microsoft Academic Search

Controversy surrounds the classification of posttraumatic stress disorder (PTSD), particularly in children and adolescents with traumatic brain injury (TBI). In these populations, it is difficult to differentiate TBI-related organic memory loss from dissociative amnesia. Several alternative PTSD classification algorithms have been proposed for use with children. This paper investigates DSM-IV-TR and alternative PTSD classification algorithms, including and excluding the dissociative

Greg Iselin; Robyne Le Brocque; Justin Kenardy; Vicki Anderson; Lynne McKinlay

2010-01-01

187

Embedding filtering criteria into a wrapper marker selection method for brain tumor classification: an application on metabolic peak area ratios  

Microsoft Academic Search

The purpose of this study is to identify reliable sets of metabolic markers that provide accurate classification of complex brain tumors and facilitate the process of clinical diagnosis. Several ratios of metabolites are tested alone or in combination with imaging markers. A wrapper feature selection and classification methodology is studied, employing Fisher's criterion for ranking the markers. The set of

M. G. Kounelakis; M. E. Zervakis; G. C. Giakos; G. J. Postma; L. M. C. Buydens; X. Kotsiakis

2011-01-01

188

From genotypes to phenotypes: classification of the tumour profiles for different variants of the cadherin adhesion pathway  

NASA Astrophysics Data System (ADS)

The E-cadherin adhesive profile expressed by a tumour is a characterization of the intracellular and intercellular protein interactions that control cell-cell adhesion. Within the intracellular proteins that determine the tumour adhesive profile, Src and PI3 are two essentials to initiate the formation of the E-cadherin adhesion complex. On the other hand, Src has also the capability of disrupting the ?-catenin-E-cadherin complex and down-regulating cell-cell adhesion. In this paper, using a multi-scale mathematical model, we study the role of each of these proteins in the adhesive profile and invasive properties of the tumour. To do this, we create three versions of an intracellular model that explains the interplay between the proteins E-cadherin, ?-catenin, Src and PI3; and we couple them to the strength of the cell-cell adhesion forces within an individual-cell-based model. The simulation results show how the tumour profile and its aggressive potential may change depending on the intrinsic characteristics of the protein pathways, and how these pathways may influence the early stages of cancer invasion. Our major findings may be summarized as follows. (1) Intermediate levels of Src synthesis rates generate the least invasive tumour phenotype. (2) Conclusions drawn from findings obtained from the intracellular molecular dynamics (here cadherin-catenin binding complexes) to the multi-cellular invasive potential of a tumour may be misleading or erroneous. The conclusions should be validated in a multi-cellular context on timescales relevant for population growth. (3) Monoclonal populations of more cohesive cells with otherwise equal properties tend to grow slower. (4) Less cohesive cells tend to outcompete more cohesive cells. (5) Less cohesive cells have a larger probability of invasion as migration forces can more easily outbalance cohesive forces.

Ramis-Conde, Ignacio; Drasdo, Dirk

2012-06-01

189

Feed-forward hierarchical model of the ventral visual stream applied to functional brain image classification.  

PubMed

Functional brain imaging is a common tool in monitoring the progression of neurodegenerative and neurological disorders. Identifying functional brain imaging derived features that can accurately detect neurological disease is of primary importance to the medical community. Research in computer vision techniques to identify objects in photographs have reported high accuracies in that domain, but their direct applicability to identifying disease in functional imaging is still under investigation in the medical community. In particular, Serre et al. ([2005]: In: IEEE Conference on Computer Vision and Pattern Recognition (CVPR-05). pp 994-1000) introduced a biophysically inspired filtering method emulating visual processing in striate cortex which they applied to perform object recognition in photographs. In this work, the model described by Serre et al. [2005] is extended to three-dimensional volumetric images to perform signal detection in functional brain imaging (PET, SPECT). The filter outputs are used to train both neural network and logistic regression classifiers and tested on two distinct datasets: ADNI Alzheimer's disease 2-deoxy-D-glucose (FDG) PET and National Football League players Tc99m HMPAO SPECT. The filtering pipeline is analyzed to identify which steps are most important for classification accuracy. Our results compare favorably with other published classification results and outperform those of a blinded expert human rater, suggesting the utility of this approach. Hum Brain Mapp, 2012. © 2012 Wiley Periodicals, Inc. PMID:22847891

Keator, David B; Fallon, James H; Lakatos, Anita; Fowlkes, Charless C; Potkin, Steven G; Ihler, Alexander

2012-07-30

190

An antigen associated with mesenchyme in human tumours that cross-reacts with brain glycoprotein.  

PubMed Central

Anti-NSA3 antiserum was found to react with many kinds of benign and malignant tumours, as well as foetal skin and intestinal extracts. The corresponding antigens isolated from nervous tissue, benign breast adenoma, and a fibrosarcoma were compared. Immunoprecipitation cannot distinguish between these antigens, and their amino-acid contents were comparable. However, immuno-absorption identified an antigenic determinant that was confined to nervous tissue. Indirect immunofluorescence further confirmed the validity of the concept of a nervous form vs a mesenchymal form of the antigen. Furthermore, immunofluorescence enabled the localization of the antigen found in non-nervous tissue to mesenchyme (mesenchyme-associated antigen: MAA), whether the mesenchymal tissue be normal (foetal organs), tumoral (fibrosarcoma) or reactional (connective-tissue stroma of epithelial tumours). Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6

Delpech, B.; Delpech, A.; Girard, N.; Chauzy, C.; Laumonier, R.

1979-01-01

191

Case-control study on risk factors for leukaemia and brain tumours in children under 5 years in Germany.  

PubMed

In the context of a case control study on the cancer risk for children under five by distance to the nearest nuclear power plant, we collected information on other risk factors in a subset. We present the interview study as if it had been an independent study. Parents of 471 cases with Leukaemia, Lymphoma or CNS (Central Nervous System)-tumour from the German Childhood Cancer Registry, diagnosed at age under 5 in the years 1993-2003, and 1,457 matched controls were to be interviewed. For Leukaemia, 243 cases/604 controls, and for CNS 102 cases/246 controls participated, lymphoma cases were too few. Questions related to social status, ionizing radiation, pregnancy and birth, immune system, and selected toxins. The analysis is exploratory in nature; variables were selected by backward elimination. For leukaemia we found a significant protective effect of social contacts (OR=0.50, 95% CI [0.29;0.87]) and a risk for high birth weight (OR=1.96 95% CI [1.12;3.41] comparing >4,000 g to "normal"). We could not reproduce other associations reported in the literature such as a negative association with allergies. For CNS tumours we found a significant protective effect of social contacts (OR=0.30 95% CI [0.13;0.72]), of pesticides and herbicides (OR=0.39 95% CI [0.18;0.83]) and an increased risk for low birth weight (p=0.0232). This study on risk factors for childhood leukaemia and brain tumours is relatively small and exploratory. We could reproduce some major associations reported in the literature (leukaemia: social contacts and high birth weight) but not others. Some observations may be reporting artefacts or self selection artefacts. PMID:19890788

Spix, C; Schulze-Rath, R; Kaatsch, P; Blettner, M

2009-11-04

192

Wireless brain-machine interface using EEG and EOG: brain wave classification and robot control  

NASA Astrophysics Data System (ADS)

A brain-machine interface (BMI) links a user's brain activity directly to an external device. It enables a person to control devices using only thought. Hence, it has gained significant interest in the design of assistive devices and systems for people with disabilities. In addition, BMI has also been proposed to replace humans with robots in the performance of dangerous tasks like explosives handling/diffusing, hazardous materials handling, fire fighting etc. There are mainly two types of BMI based on the measurement method of brain activity; invasive and non-invasive. Invasive BMI can provide pristine signals but it is expensive and surgery may lead to undesirable side effects. Recent advances in non-invasive BMI have opened the possibility of generating robust control signals from noisy brain activity signals like EEG and EOG. A practical implementation of a non-invasive BMI such as robot control requires: acquisition of brain signals with a robust wearable unit, noise filtering and signal processing, identification and extraction of relevant brain wave features and finally, an algorithm to determine control signals based on the wave features. In this work, we developed a wireless brain-machine interface with a small platform and established a BMI that can be used to control the movement of a robot by using the extracted features of the EEG and EOG signals. The system records and classifies EEG as alpha, beta, delta, and theta waves. The classified brain waves are then used to define the level of attention. The acceleration and deceleration or stopping of the robot is controlled based on the attention level of the wearer. In addition, the left and right movements of eye ball control the direction of the robot.

Oh, Sechang; Kumar, Prashanth S.; Kwon, Hyeokjun; Varadan, Vijay K.

2012-03-01

193

Corticosteroids induce chemotherapy resistance in the majority of tumour cells from bone, brain, breast, cervix, melanoma and neuroblastoma.  

PubMed

Glucocorticoids (GCs) such as dexamethasone (DEX) have been widely used as co-medication in cancer therapy because they have potent proapoptotic properties in lymphoid cells, can reduce nausea, and alleviate acute toxic effects in healthy tissue. However, GCs are used in a supportive-care role, even though no prospective clinical studies have assessed the effect of these steroids on the growth of solid tumours. Data from preclinical and, to some extent, clinical studies, suggest that GCs induce treatment resistance in some solid tumours. Since it is unknown whether GC-induced resistance occurs only occasionally or is a more common phenomenon, we performed a screening study using several established cell lines from bone, brain, breast and cervix carcinoma as well as melanoma and neuroblastoma together with fresh surgical resections from patients with breast cancer. We found that DEX inhibits cisplatin and 5-fluorouracil-induced apoptosis and promotes the growth of the majority of examined malignant cells. In contrast, and as expected, DEX acted pro-apoptotically and promoted the cytotoxic effect of chemotherapy in established and primary lymphoid cells. Thus, these data demonstrate the need for detailed molecular studies to clarify the mechanism of differential glucocorticoid signaling as well as controlled, prospective clinical studies. PMID:17016664

Zhang, Chengwen; Beckermann, Benjamin; Kallifatidis, Georgios; Liu, Zheng; Rittgen, Werner; Edler, Lutz; Büchler, Peter; Debatin, Klaus-Michael; Büchler, Markus W; Friess, Helmut; Herr, Ingrid

2006-11-01

194

A parameter study to determine the optimal source neutron energy in boron neutron capture therapy of brain tumours  

NASA Astrophysics Data System (ADS)

The values of the parameters used in boron neutron capture therapy (BNCT) to calculate a given dose to human tissue vary with patients due to different physical, biological and/or medical circumstances. Parameters include the tissue dimensions, the 10B concentration and the relative biological effectiveness (RBE) factors for the different dose components associated with BNCT. Because there is still no worldwide agreement on RBE values, more often than not, average values for these parameters are used. It turns out that the RBE-problem can be circumvented by taking into account all imaginable parameter values. Approaching this quest from another angle: the outcome will also provide the parameters (and values) which influence the optimal source neutron energy. For brain tumours it turns out that the 10B concentration, the RBE factors for 10B as well as fast neutrons, together with the dose limit set for healthy tissue, affect the optimal BNCT source neutron energy. By using source neutrons of a few keV together with neutrons of a few eV, it ensures that, under all imaginable circumstances, a maximum of alpha (and lithium) particles can be delivered in the tumour.

Nievaart, V. A.; Moss, R. L.; Kloosterman, J. L.; van der Hagen, T. H. J. J.; van Dam, H.

2004-09-01

195

In-phantom two-dimensional thermal neutron distribution for intraoperative boron neutron capture therapy of brain tumours  

NASA Astrophysics Data System (ADS)

The aim of this study was to determine the in-phantom thermal neutron distribution derived from neutron beams for intraoperative boron neutron capture therapy (IOBNCT). Gold activation wires arranged in a cylindrical water phantom with (void-in-phantom) or without (standard phantom) a cylinder styrene form placed inside were irradiated by using the epithermal beam (ENB) and the mixed thermal-epithermal beam (TNB-1) at the Japan Research Reactor No 4. With ENB, we observed a flattened distribution of thermal neutron flux and a significantly enhanced thermal flux delivery at a depth compared with the results of using TNB-1. The thermal neutron distribution derived from both the ENB and TNB-1 was significantly improved in the void-in-phantom, and a double high dose area was formed lateral to the void. The flattened distribution in the circumference of the void was observed with the combination of ENB and the void-in-phantom. The measurement data suggest that the ENB may provide a clinical advantage in the form of an enhanced and flattened dose delivery to the marginal tissue of a post-operative cavity in which a residual and/or microscopically infiltrating tumour often occurs. The combination of the epithermal neutron beam and IOBNCT will improve the clinical results of BNCT for brain tumours.

Yamamoto, T.; Matsumura, A.; Yamamoto, K.; Kumada, H.; Shibata, Y.; Nose, T.

2002-07-01

196

Classification of mathematics deficiency using shape and scale analysis of 3D brain structures  

NASA Astrophysics Data System (ADS)

We investigate the use of a recent technique for shape analysis of brain substructures in identifying learning disabilities in third-grade children. This Riemannian technique provides a quantification of differences in shapes of parameterized surfaces, using a distance that is invariant to rigid motions and re-parameterizations. Additionally, it provides an optimal registration across surfaces for improved matching and comparisons. We utilize an efficient gradient based method to obtain the optimal re-parameterizations of surfaces. In this study we consider 20 different substructures in the human brain and correlate the differences in their shapes with abnormalities manifested in deficiency of mathematical skills in 106 subjects. The selection of these structures is motivated in part by the past links between their shapes and cognitive skills, albeit in broader contexts. We have studied the use of both individual substructures and multiple structures jointly for disease classification. Using a leave-one-out nearest neighbor classifier, we obtained a 62.3% classification rate based on the shape of the left hippocampus. The use of multiple structures resulted in an improved classification rate of 71.4%.

Kurtek, Sebastian; Klassen, Eric; Gore, John C.; Ding, Zhaohua; Srivastava, Anuj

2011-03-01

197

Biomarker expression and St Gallen molecular subtype classification in primary tumours, synchronous lymph node metastases and asynchronous relapses in primary breast cancer patients with 10 years' follow-up.  

PubMed

Molecular profiles of asynchronous breast cancer metastases are of clinical relevance to individual patients' treatment, whereas the role of profiles in synchronous lymph node metastases is not defined. The present study aimed to assess individual biomarkers and molecular subtypes according to the St Gallen classification in primary breast tumours, synchronous lymph node metastases and asynchronous relapses and relate the results to 10-year breast cancer mortality (BCM). Tissue microarrays were constructed from archived tissue blocks of primary tumours (N = 524), synchronous lymph node metastases (N = 147) and asynchronous relapses (N = 36). The samples were evaluated by two independent pathologists according to oestrogen receptor (ER), progesterone receptor (PR), Ki67 and human epidermal growth factor receptor 2 (HER2) by immunohistochemistry and in situ hybridisation. The expression of biomarkers and molecular subtypes in the primary tumour was compared with that in the synchronous lymph node metastases and relapses, and related to 10-year BCM. Discordances were found between primary tumours and relapses (ER: p = 0.006, PR: p = 0.04, Ki67: p = 0.02, HER2: p = 0.02, St Gallen subtypes: p = 0.07) but not between primary tumours and metastatic lymph node. Prognostic information was gained by the molecular subtype classification in primary tumours and nodal metastases; triple negative subtype had the highest BCM compared with the luminal A subtype (primary tumours: HR 4.0; 95 % CI 2.0-8.2, p < 0.001, lymph node metastases: HR 3.5; 95 % CI 1.3-9.7, p = 0.02). When a shift in subtype inherence between primary tumour and metastatic lymph node was identified, the prognosis seemed to follow the subtype of the lymph node. Molecular profiles are not stable throughout tumour progression in breast cancer. Prognostic information for individual patients appears to be available from the analysis of biomarker expression in synchronous metastatic lymph nodes. The study supports biomarker analysis also in asynchronous relapses. PMID:23807420

Falck, Anna-Karin; Bendahl, Pär-Ola; Chebil, Gunilla; Olsson, Hans; Fernö, Mårten; Rydén, Lisa

2013-06-27

198

[Acquired brain injury: a proposal for its definition, diagnostic criteria and classification].  

PubMed

Acquired brain injury is a heterogeneous clinical concept that goes beyond the limits of the classical medical view, which tends to define processes and diseases on the grounds of a single causation. Although in the medical literature it appears fundamentally associated to traumatic brain injury, there are many other causes and management is similar in all of them, during the post-acute and chronic phases, as regards the measures to be taken concerning rehabilitation and attention to dependence. Yet, despite being an important health issue, today we do not have a set of diagnostic criteria or a classification for this condition. This is a serious handicap when it comes to carrying out epidemiological studies, designing specific care programmes and comparing results among different programmes and centres. Accordingly, the Extremadura Acquired Brain Injury Health Care Plan working group has drawn up these proposed diagnostic criteria, definition and classification. The proposal is intended to be essentially practical, its main purpose being to allow correct identification of the cases that must be attended to and to optimise the use of neurorehabilitation and attention to dependence resources, thereby ensuring attention is provided on a fair basis. PMID:22403149

Castellanos-Pinedo, Fernando; Cid-Gala, Manuel; Duque, Pablo; Ramirez-Moreno, José M; Zurdo-Hernández, José M

2012-03-16

199

Development of a new autofluorescence probe for the analysis of normal and tumour brain tissues  

NASA Astrophysics Data System (ADS)

Fluorescence spectroscopy of endogenous emission of brain tumors, in particular glioblastoma multiforme, will be used for intraoperative localization of brain tumor margins. Our future surgeon's probe aims to discriminate tumor from normal brain tissues using beta and autofluorescence detection at the same time. Within this study we have implemented C6 glioma cells into rat brains to analyze the endogenous fluorescence of tumor and normal rat brain tissue. Systematic differences have been observed when comparing the autofluorescence spectra obtained from white and grey matters: both the fluorescence intensity and the shape of the spectra differ. These results were obtained by means of a 2-fiber probe, one used to guide the laser to the tissue, the other for fluorescence light collection. Excitation light was delivered by a 405 nm picosecond laser and fluorescence detection was realized by a CCD-camera. In parallel we have developed brain phantoms allowing systematic analysis of fiber - sample geometries. Based on gelatin gels, they include silica particles with 235 and 329 nm diameters to simulate the diffusion characteristics of the tissue, ink for the absorption characteristics of the tissue and organic dyes like Rhodamin B to replace biofluorophores.

Siebert, R.; Vu Thi, M. H.; Jean, F.; Charon, Y.; Collado-Hilly, M.; Duval, M. A.; Mandat, T.; Menard, L.; Palfi, S.; Tordjmann, T.

2008-05-01

200

A quantitative comparison of metabolite signals as detected by in vivo MRS with ex vivo 1H HR-MAS for childhood brain tumours.  

PubMed

(1)H MRS provides a powerful method for investigating tumour metabolism by allowing the measurement of metabolites in vivo. Recently, the technique of (1)H high-resolution magic angle spinning (HR-MAS) has been shown to produce high-quality data, allowing the accurate measurement of many metabolites present in unprocessed biopsy tissue. The purpose of this study was to evaluate the agreement between the techniques of in vivo MRS and ex vivo HR-MAS for investigating childhood brain tumours. Short-TE (30 ms), single-voxel, in vivo MRS was performed on 16 paediatric patients with brain tumours at 1.5 T. A frozen biopsy sample was available for each patient. HR-MAS was performed on the biopsy samples, and metabolite quantities were determined from the MRS and HR-MAS data using the LCModel and TARQUIN algorithms, respectively. Linear regression was performed on the metabolite quantities to asses the agreement between MRS and HR-MAS. Eight of the 12 metabolite quantities were found to correlate significantly (P < 0.05). The four worst correlating metabolites were aspartate, scyllo-inositol, glycerophosphocholine and N-acetylaspartate, and, except for glycerophosphocholine, this error was reflected in their higher Cramer-Rao lower bounds (CRLBs), suggesting that low signal-to-noise was the greatest source of error for these metabolites. Glycerophosphocholine had a lower CRLB implying that interference with phosphocholine and choline was the most significant source of error. The generally good agreement observed between the two techniques suggests that both MRS and HR-MAS can be used to reliably estimate metabolite quantities in brain tumour tissue and that tumour heterogeneity and metabolite degradation do not have an important effect on the HR-MAS metabolite profile for the tumours investigated. HR-MAS can be used to improve the analysis and understanding of MRS data. PMID:19067434

Wilson, Martin; Davies, Nigel P; Grundy, Richard G; Peet, Andrew C

2009-02-01

201

CLASSIFICATION  

NSDL National Science Digital Library

Project Overview: Classification is grouping similar objects together. When you go into a grocery store, you see fresh fruits and vegetables, frozen food, cereal, and pet suplies in different aisles. Imagine how difficult life would be if you went into a store, and the aisles were not labeled to tell you where to find the items! You don't have to be a scientist to use classification! You use classification when you group your IPOD music into different genres and when you divide your dark colored clothing from light colors to do laundry. You might even use it to sort Halloween candy into 4 groups: chocolate candy, hard candy, chewy candy, and gum. The science of classification is called taxonomy. Taxonomy classifies organisms based on evolutionary relationships and describes and names organisms with a two-part name: genus and species. Scientists use taxonomy to identify unknown organisms by using books called field guides or by using taxonomic keys (also called dichomotous keys). Project Objective: As a class,you will be previewing and answering some questions about some classification resources to learn how to use a dichotomous key, how to key a specimen, and to help you write your own dichotomous key for school items. Project: Get a sheet of notebook paper and pencil and refer to the websites to find the answers to the questions. One way to classify objects is to create a "tree" to group similar objects together.Open hierarchical classfication of objects to the second page and find the diagram of common household objects. See how all the ...

Ballew, Mrs.

2010-10-17

202

Effect of transfection of a Drosophila topoisomerase II gene into a human brain tumour cell line intrinsically resistant to etoposide.  

PubMed Central

The human brain tumour cell line HBT20 is intrinsically resistant to etoposide and does not express mdr-1 mRNA. These studies were conducted to determine whether transfecting a Drosophila (D) topoisomerase II (topo II) gene into HBT20 cells could increase their sensitivity to etoposide. A D-topo II construct in a pMAMneo vector under the control of a mouse mammary tumour virus (MMTV) promoter was transfected into HBT20 cells. The gene is inducible by dexamethasone (Dex). The growth rate of the transfected cells and percentage of the cells in G1, S and G2M was no different than the parental cells. Survival after etoposide exposure (10 microM x 2 h) was measured by colony formation. Parental cells and cells transfected by pMAMneo vector alone showed no enhanced etoposide sensitivity after 24 h of Dex stimulation. By contrast, D-topo II transfected cells were sensitised 3-fold when etoposide treatment was preceded by 24 h Dex stimulation. Northern blotting and Western blotting confirmed that Dex had induced D-topo II expression in the sensitised cells. However, in D-topo II-transfected cells increasing the duration of Dex stimulation to 48 h eliminated the sensitisation to etoposide although increased MMTV promoter activity and expression of the D-topo II gene persisted. Measurement of endogenous human topo-II mRNA and protein revealed a decrease after Dex exposure of greater than 24 h. At these distal times, the total cellular topo II levels (endogenous + exogenous) may be decreased, which may explain why increased sensitivity to etoposide could no longer be demonstrated. This model suggests that D-topo II gene transfection can sensitise de novo resistant HBT20 cells to etoposide but that the time frame of that sensitisation is limited. Images Figure 1 Figure 2 Figure 3 Figure 5

Asano, T.; Zwelling, L. A.; An, T.; McWatters, A.; Herzog, C. E.; Mayes, J.; Loughlin, S. M.; Kleinerman, E. S.

1996-01-01

203

In vivo measurements of regional cerebral blood flow and blood volume in patients with brain tumours using positron emission tomography  

Microsoft Academic Search

Summary In 21 patients with cerebral tumours regional cerebral blood flow (rCBF) and blood volume (rCBV) were measured. In the tumours, blood flow and volume were variable and unrelated even in tumours of the same type and grade.

A. A. Lammertsma; R. J. S. Wise; T. Jones

1983-01-01

204

Classification of motor imagery tasks for brain-computer interface applications by means of two equivalent dipoles analysis  

Microsoft Academic Search

We have developed a novel approach using source analysis for classifying motor imagery tasks. Two-equivalent-dipoles analysis was proposed to aid classification of motor imagery tasks for brain-computer interface (BCI) applications. By solving the electroencephalography (EEG) inverse problem of single trial data, it is found that the source analysis approach can aid classification of motor imagination of left- or right-hand movement

Baharan Kamousi; Zhongming Liu; Bin He

2005-01-01

205

Voxel-based discriminant map classification on brain ventricles for Alzheimer's disease  

NASA Astrophysics Data System (ADS)

One major hallmark of the Alzheimer's disease (AD) is the loss of neurons in the brain. In many cases, medical experts use magnetic resonance imaging (MRI) to qualitatively measure the neuronal loss by the shrinkage or enlargement of the structures-of-interest. Brain ventricle is one of the popular choices. It is easily detectable in clinical MR images due to the high contrast of the cerebro-spinal fluid (CSF) with the rest of the parenchyma. Moreover, atrophy in any periventricular structure will directly lead to ventricle enlargement. For quantitative analysis, volume is the common choice. However, volume is a gross measure and it cannot capture the entire complexity of the anatomical shape. Since most existing shape descriptors are complex and difficult-to-reproduce, more straightforward and robust ways to extract ventricle shape features are preferred in the diagnosis. In this paper, a novel ventricle shape based classification method for Alzheimer's disease has been proposed. Training process is carried out to generate two probability maps for two training classes: healthy controls (HC) and AD patients. By subtracting the HC probability map from the AD probability map, we get a 3D ventricle discriminant map. Then a matching coefficient has been calculated between each training subject and the discriminant map. An adjustable cut-off point of the matching coefficients has been drawn for the two classes. Generally, the higher the cut-off point that has been drawn, the higher specificity can be achieved. However, it will result in relatively lower sensitivity and vice versa. The benchmarked results against volume based classification show that the area under the ROC curves for our proposed method is as high as 0.86 compared with only 0.71 for volume based classification method.

Wang, Jingnan; de Haan, Gerard; Unay, Devrim; Soldea, Octavian; Ekin, Ahmet

2009-02-01

206

Correction for the Presence of Intravascular Oxygen15 in the Steady-State Technique for Measuring Regional Oxygen Extraction Ratio in the Brain: 2. Results in Normal Subjects and Brain Tumour and Stroke Patients  

Microsoft Academic Search

Summary: Values of regional cerebral oxygen extraction ratio and oxygen utilisation obtained with the oxygen-15 steady-state inhalation technique have been found to be overestimated due to the signal from intravascular oxygen-15. A previously described method to correct for this intravascular component has been applied to a series of studies on normal subjects, and on brain tumour and stroke patients. With

Adriaan A. Lammertsma; Richard J. S. Wise; Jon D. Heather; Jeremy M. Gibbs; Klaus L. Leenders; Richard S. J. Frackowiak; Christopher G. Rhodes; Terry Jones; Lammertsma

1983-01-01

207

Challenges relating to solid tumour brain metastases in clinical trials, part 1: patient population, response, and progression. A report from the RANO group.  

PubMed

Therapeutic outcomes for patients with brain metastases need to improve. A critical review of trials specifically addressing brain metastases shows key issues that could prevent acceptance of results by regulatory agencies, including enrolment of heterogeneous groups of patients and varying definitions of clinical endpoints. Considerations specific to disease, modality, and treatment are not consistently addressed. Additionally, the schedule of CNS imaging and consequences of detection of new or progressive brain metastases in trials mainly exploring the extra-CNS activity of systemic drugs are highly variable. The Response Assessment in Neuro-Oncology (RANO) working group is an independent, international, collaborative effort to improve the design of trials in patients with brain tumours. In this two-part series, we review the state of clinical trials of brain metastases and suggest a consensus recommendation for the development of criteria for future clinical trials. PMID:23993384

Lin, Nancy U; Lee, Eudocia Q; Aoyama, Hidefumi; Barani, Igor J; Baumert, Brigitta G; Brown, Paul D; Camidge, D Ross; Chang, Susan M; Dancey, Janet; Gaspar, Laurie E; Harris, Gordon J; Hodi, F Stephen; Kalkanis, Steven N; Lamborn, Kathleen R; Linskey, Mark E; Macdonald, David R; Margolin, Kim; Mehta, Minesh P; Schiff, David; Soffietti, Riccardo; Suh, John H; van den Bent, Martin J; Vogelbaum, Michael A; Wefel, Jeffrey S; Wen, Patrick Y

2013-09-01

208

The neurodevelopmental price of survival in children with malignant brain tumours  

Microsoft Academic Search

Increasing survival rates in malignant brain tumors treatment have directed attention to the side effects of long-term disease\\u000a control. Nevertheless, although the treatment protocols are continuously remodelled, the quality of life of children surviving\\u000a for a long time is still poor. The most severe sequelae are neurocognitive disorders, which are associated with neurobehavioural\\u000a alterations. The last are partly derived directly

Daria Riva; Cesare Giorgi

2000-01-01

209

Survival analysis for apparent diffusion coefficient measures in children with embryonal brain tumours.  

PubMed

Embryonal brain tumors constitute a large and important subgroup of pediatric brain tumors. Apparent diffusion coefficient (ADC) measures have been previously used in the analysis of these tumors. We investigated a newly described ADC-derived parameter, the apparent transient coefficient in tumor (ATCT), a measure of the gradient change of ADC from the peri-tumoral edema into the tumor core, to study whether ATCT correlates with survival outcome. Sixty-one patients with histologically proven embryonal brain tumors and who had diffusion-weighted imaging (DWI) as part of their clinical imaging were enrolled in a retrospective study correlating ADC measures with survival. Kaplan-Meier survival curves were constructed for extent of surgical resection, age <3 years at diagnosis, tumor type, and metastasis at presentation. A multivariate survival analysis was performed that took into consideration ATCT and variables found to be significant in the Kaplan-Meier analysis as covariates. Results from the multivariate analysis showed that ATCT was the only significant covariate (P < .001). Survival analysis using Kaplan-Meier curves, dividing the patients into 4 groups of increasing values of ATCT, showed that more negative values of ATCT were significantly associated with a poorer prognosis (P < .001). A statistically significant difference was observed for survival data with respect to the change in ADC from edema into the tumor volume. Results show that more negative ATCT values are significantly associated with a poorer survival among children with embryonal brain tumors, irrespective of tumor type, extent of resection, age <3 years at diagnosis, and metastasis at presentation. PMID:22954494

Grech-Sollars, Matthew; Saunders, Dawn E; Phipps, Kim P; Clayden, Jonathan D; Clark, Chris A

2012-09-06

210

Classification  

NASA Astrophysics Data System (ADS)

A supervised learning task involves constructing a mapping from input data (normally described by several features) to the appropriate outputs. A set of training examples— examples with known output values—is used by a learning algorithm to generate a model. This model is intended to approximate the mapping between the inputs and outputs. This model can be used to generate predicted outputs for inputs that have not been seen before. Within supervised learning, one type of task is a classification learning task, in which each output is one or more classes to which the input belongs. For example, we may have data consisting of observations of sunspots. In a classification learning task, our goal may be to learn to classify sunspots into one of several types. Each example may correspond to one candidate sunspot with various measurements or just an image. A learning algorithm would use the supplied examples to generate a model that approximates the mapping between each supplied set of measurements and the type of sunspot. This model can then be used to classify previously unseen sunspots based on the candidate’s measurements. The generalization performance of a learned model (how closely the target outputs and the model’s predicted outputs agree for patterns that have not been presented to the learning algorithm) would provide an indication of how well the model has learned the desired mapping. More formally, a classification learning algorithm L takes a training set T as its input. The training set consists of |T| examples or instances. It is assumed that there is a probability distribution D from which all training examples are drawn independently—that is, all the training examples are independently and identically distributed (i.i.d.). The ith training example is of the form (x_i, y_i), where x_i is a vector of values of several features and y_i represents the class to be predicted.* In the sunspot classification example given above, each training example would represent one sunspot’s classification (y_i) and the corresponding set of measurements (x_i). The output of a supervised learning algorithm is a model h that approximates the unknown mapping from the inputs to the outputs. In our example, h would map from the sunspot measurements to the type of sunspot. We may have a test set S—a set of examples not used in training that we use to test how well the model h predicts the outputs on new examples. Just as with the examples in T, the examples in S are assumed to be independent and identically distributed (i.i.d.) draws from the distribution D. We measure the error of h on the test set as the proportion of test cases that h misclassifies: 1/|S| Sigma(x,y union S)[I(h(x)!= y)] where I(v) is the indicator function—it returns 1 if v is true and 0 otherwise. In our sunspot classification example, we would identify additional examples of sunspots that were not used in generating the model, and use these to determine how accurate the model is—the fraction of the test samples that the model classifies correctly. An example of a classification model is the decision tree shown in Figure 23.1. We will discuss the decision tree learning algorithm in more detail later—for now, we assume that, given a training set with examples of sunspots, this decision tree is derived. This can be used to classify previously unseen examples of sunpots. For example, if a new sunspot’s inputs indicate that its "Group Length" is in the range 10-15, then the decision tree would classify the sunspot as being of type “E,” whereas if the "Group Length" is "NULL," the "Magnetic Type" is "bipolar," and the "Penumbra" is "rudimentary," then it would be classified as type "C." In this chapter, we will add to the above description of classification problems. We will discuss decision trees and several other classification models. In particular, we will discuss the learning algorithms that generate these classification models, how to use them to classify new

Oza, Nikunj

2012-03-01

211

Improved CSF classification and lesion detection in MR brain images with multiple sclerosis  

NASA Astrophysics Data System (ADS)

The study deals with the challenging task of automatic segmentation of MR brain images with multiple sclerosis lesions (MSL). Multi-Channel data is used, including "fast fluid attenuated inversion recovery" (fast FLAIR or FF), and statistical modeling tools are developed, in order to improve cerebrospinal fluid (CSF) classification and to detect MSL. Two new concepts are proposed for use within an EM framework. The first concept is the integration of prior knowledge as it relates to tissue behavior in different MRI modalities, with special attention given to the FF modality. The second concept deals with running the algorithm on a subset of the input that is most likely to be noise- and artifact-free data. This enables a more reliable learning of the Gaussian mixture model (GMM) parameters for brain tissue statistics. The proposed method focuses on the problematic CSF intensity distribution, which is a key to improved overall segmentation and lesion detection. A level-set based active contour stage is performed for lesion delineation, using gradient and shape properties combined with previously learned region intensity statistics. In the proposed scheme there is no need for preregistration of an atlas, a common characteristic in brain segmentation schemes. Experimental results on real data are presented.

Wolff, Yulian; Miron, Shmuel; Achiron, Anat; Greenspan, Hayit

2007-03-01

212

Classification of brain tumor type and grade using MRI texture and shape in a machine learning scheme  

PubMed Central

The objective of this study is to investigate the use of pattern classification methods for distinguishing different types of brain tumors, such as primary gliomas from metastases, and also for grading of gliomas. The availability of an automated computer analysis tool that is more objective than human readers can potentially lead to more reliable and reproducible brain tumor diagnostic procedures. A computer-assisted classification method combining conventional MRI and perfusion MRI is developed and used for differential diagnosis. The proposed scheme consists of several steps including ROI definition, feature extraction, feature selection and classification. The extracted features include tumor shape and intensity characteristics as well as rotation invariant texture features. Feature subset selection is performed using Support Vector Machines (SVMs) with recursive feature elimination. The method was applied on a population of 102 brain tumors histologically diagnosed as metastasis (24), meningiomas (4), gliomas WHO grade 2 (22), gliomas WHO grade 3 (18), and glioblastomas (34). The binary SVM classification accuracy, sensitivity, and specificity, assessed by leave-one-out cross-validation, were respectively 85%, 87%, and 79% for discrimination of metastases from gliomas, and 88%, 85%, and 96% for discrimination of high grade (grade III and IV) from low grade (grade II) neoplasms. Multi-class classification was also performed via a one-versus-all voting scheme.

Zacharaki, Evangelia I.; Wang, Sumei; Chawla, Sanjeev; Yoo, Dong Soo; Wolf, Ronald; Melhem, Elias R.; Davatzikos, Christos

2010-01-01

213

Epidemiology of childhood brain tumours in Yorkshire, UK, 1974-95: geographical distribution and changing patterns of occurrence.  

PubMed Central

From a high-quality population-based register of children with cancer, 455 cases diagnosed with central nervous system (CNS) tumours were analysed to examine patterns of occurrence and geographical distribution. There was a significant increase of 1.8% (95% CI 0.5-3.1, P < 0.01) in average annual incidence for all CNS tumours, mainly accounted for by a 3.1% rise (95% CI 0.1-6.1, P < 0.05) in primitive neuroectodermal tumours (PNETs) over the 22-year period 1974-95. These increases were not explained by an increase in the proportion of histologically verified tumours. In the most recent time period (1986-95), astrocytomas occurred more commonly than previously in 0 to 4-year olds. Geographical differences in incidence were evident at a large scale, between counties, for all tumours and astrocytomas, with lower rates in the most urbanized areas. At the level of census district and electoral wards, no association between incidence of CNS tumours and socioeconomic group, person-based population density or ethnicity was observed using Poisson regression modelling. Based on small-scale census geography, the patterns of distribution of CNS tumours do not suggest strong associations with geographical determinants of risk. This study finds a rising incidence of all CNS tumours and particularly primitive neuroectodermal tumours and shows that astrocytomas appear to be occurring at a younger age, most probably because of improved diagnosis with non-invasive technology.

McKinney, P. A.; Parslow, R. C.; Lane, S. A.; Bailey, C. C.; Lewis, I.; Picton, S.; Cartwright, R. A.

1998-01-01

214

Multichannel fusion models for the parametric classification of differential brain activity.  

PubMed

This paper introduces parametric multichannel fusion models to exploit the different but complementary brain activity information recorded from multiple channels in order to accurately classify differential brain activity into their respective categories. A parametric weighted decision fusion model and two parametric weighted data fusion models are introduced for the classification of averaged multichannel evoked potentials (EPs). The decision fusion model combines the independent decisions of each channel classifier into a decision fusion vector and a parametric classifier is designed to determine the EP class from the discrete decision fusion vector. The data fusion models include the weighted EP-sum model in which the fusion vector is a linear combination of the multichannel EPs and the EP-concatenation model in which the fusion vector is a vector-concatenation of the multichannel EPs. The discrete Karhunen-Loeve transform (DKLT) is used to select features for each channel classifier and from each data fusion vector. The difficulty in estimating the probability density function (PDF) parameters from a small number of averaged EPs is identified and the class conditional PDFs of the feature vectors of averaged EPs are, therefore, derived in terms of the PDFs of the single-trial EPs. Multivariate parametric classifiers are developed for each fusion strategy and the performances of the different strategies are compared by classifying 14-channel EPs collected from five subjects involved in making explicit match/mismatch comparisons between sequentially presented stimuli. It is shown that the performance improves by incorporating weights in the fusion rules and that the best performance is obtained using multichannel EP concatenation. It is also noted that the fusion strategies introduced are also applicable to other problems involving the classification of multicategory multivariate signals generated from multiple sources. PMID:16285391

Gupta, Lalit; Chung, Beomsu; Srinath, Mandyam D; Molfese, Dennis L; Kook, Hyunseok

2005-11-01

215

Effects of a Dynamic Reference Frame in Mental Task Classification for EEG-Based Brain-Machine Interface  

Microsoft Academic Search

We study the effects of a moving reference frame on the classification of different mental tasks in a brain-machine interface (BMI). We use the band powers and power differences of the electroencephalogram (EEG) signals from 8 surface electrodes during 5 pre-determined mental tasks as the features for the neural network (NN) mental task classifier. We compare the NN classifier performance

M. S. Abundo; L. G. Sison

2006-01-01

216

Mild traumatic brain injury literature review and proposed changes to classification.  

PubMed

Mild traumatic brain injury (mTBI) reportedly occurs in 8-22% of U.S. servicemembers who conduct combat operations in Afghanistan and Iraq. The current definition for mTBI found in the medical literature, to include the Department of Defense (DoD) and Veterans Administration (VA) clinical practice guidelines is limited by the parameters of loss of consciousness, altered consciousness, or post-traumatic amnesia, and does not account for other constellations of potential symptoms. Although mTBI symptoms typically resolve within seven days, some servicemembers experience symptoms that continue for weeks, months, or years following an injury. Mild TBI is one of few disorders in medicine where a benign and misleading diagnostic classification is bestowed on patients at the time of injury, yet still can be associated with lifelong complications. This article comprehensively reviews the clin ical literature over the past 20 years and proposes a new classification for TBI that addresses acute, sub-acute, and chronic phases, and includes neurocognitive, somatic, and psychological symptom presentation. PMID:22173595

Krainin, Benjamin M; Forsten, Robert D; Kotwal, Russ S; Lutz, Robert H; Guskiewicz, Kevin M

2011-01-01

217

A method for automatic detection and classification of stroke from brain CT images.  

PubMed

Computed tomographic (CT) images are widely used in the diagnosis of stroke. In this paper, we present an automated method to detect and classify an abnormality into acute infarct, chronic infarct and hemorrhage at the slice level of non-contrast CT images. The proposed method consists of three main steps: image enhancement, detection of mid-line symmetry and classification of abnormal slices. A windowing operation is performed on the intensity distribution to enhance the region of interest. Domain knowledge about the anatomical structure of the skull and the brain is used to detect abnormalities in a rotation- and translation-invariant manner. A two-level classification scheme is used to detect abnormalities using features derived in the intensity and the wavelet domain. The proposed method has been evaluated on a dataset of 15 patients (347 image slices). The method gives 90% accuracy and 100% recall in detecting abnormality at patient level; and achieves an average precision of 91% and recall of 90% at the slice level. PMID:19965232

Chawla, Mayank; Sharma, Saurabh; Sivaswamy, Jayanthi; Kishore, L

2009-01-01

218

Detection of keratin subtypes in routinely processed cervical tissue: implications for tumour classification and the study of cervix cancer aetiology.  

PubMed

We investigated the expression of keratin subtypes 7, 8, 10, 13, 14, 17, 18 and 19 in the normal cervix, in cervical intraepithelial neoplasia (CIN) lesions and in cervical carcinomas, using a selected panel of monoclonal keratin antibodies, reactive with routinely processed, formalin fixed paraffin embedded tissue fragments. The reaction patterns derived for each keratin antibody were compared with known expression patterns of the various epithelia, previously examined in frozen tissues. Although the reactivity of the antibodies was generally acceptable, considerable modifications to the manufacturers' staining instructions were often necessary. For some antibodies, which were previously thought to be reactive with fresh frozen tissue only, we developed staining protocols rendering them reactive with routinely processed material. As with previous findings in frozen sections we observed increasing expression of keratins 7, 8, 17, 18 and 19 with increasing grade of CIN. In cervical carcinomas the differences in keratin detectability between the main categories were more pronounced than in frozen sections, probably due to fixation and processing. For routine pathology, keratin phenotyping of cervical lesions may be of value in classification. The fact that keratin 7 was detected for the first time in reserve cells, and that this keratin was also found to be expressed in a considerable number of CIN lesions and cervical carcinomas supports the suggestion that reserve cells are a common progenitor cell for these lesions. PMID:7524976

Smedts, F; Ramaekers, F; Link, M; Lauerova, L; Troyanovsky, S; Schijf, C; Vooijs, G P

1994-01-01

219

A toolbox for real-time subject-independent and subject-dependent classification of brain states from fMRI signals  

PubMed Central

There is a recent increase in the use of multivariate analysis and pattern classification in prediction and real-time feedback of brain states from functional imaging signals and mapping of spatio-temporal patterns of brain activity. Here we present MANAS, a generalized software toolbox for performing online and offline classification of fMRI signals. MANAS has been developed using MATLAB, LIBSVM, and SVMlight packages to achieve a cross-platform environment. MANAS is targeted for neuroscience investigations and brain rehabilitation applications, based on neurofeedback and brain-computer interface (BCI) paradigms. MANAS provides two different approaches for real-time classification: subject dependent and subject independent classification. In this article, we present the methodology of real-time subject dependent and subject independent pattern classification of fMRI signals; the MANAS software architecture and subsystems; and finally demonstrate the use of the system with experimental results.

Rana, Mohit; Gupta, Nalin; Dalboni Da Rocha, Josue L.; Lee, Sangkyun; Sitaram, Ranganatha

2013-01-01

220

A toolbox for real-time subject-independent and subject-dependent classification of brain states from fMRI signals.  

PubMed

There is a recent increase in the use of multivariate analysis and pattern classification in prediction and real-time feedback of brain states from functional imaging signals and mapping of spatio-temporal patterns of brain activity. Here we present MANAS, a generalized software toolbox for performing online and offline classification of fMRI signals. MANAS has been developed using MATLAB, LIBSVM, and SVMlight packages to achieve a cross-platform environment. MANAS is targeted for neuroscience investigations and brain rehabilitation applications, based on neurofeedback and brain-computer interface (BCI) paradigms. MANAS provides two different approaches for real-time classification: subject dependent and subject independent classification. In this article, we present the methodology of real-time subject dependent and subject independent pattern classification of fMRI signals; the MANAS software architecture and subsystems; and finally demonstrate the use of the system with experimental results. PMID:24151454

Rana, Mohit; Gupta, Nalin; Dalboni Da Rocha, Josue L; Lee, Sangkyun; Sitaram, Ranganatha

2013-10-17

221

Pooled analysis of two case-control studies on the use of cellular and cordless telephones and the risk of benign brain tumours diagnosed during 1997-2003.  

PubMed

The use of cellular and cordless telephones and the risk of brain tumours is of concern since the brain is a high exposure area. We present the results of a pooled analysis of two case-control studies on benign brain tumours diagnosed during 1997-2003 including answers from 1,254 (88%) cases and 2,162 (89%) controls aged 20-80 years. For acoustic neuroma, the use of analogue cellular phones gave an odds ratio (OR) of 2.9 and a 95% confidence interval (CI) of 2.0-4.3; for digital cellular phones, OR=1.5; 95% CI=1.1-2.1; and for cordless telephones, OR=1.5, 95% CI=1.04-2.0. The highest OR was found for analogue phones with a latency period of >15 years; OR=3.8, 95% CI=1.4-10. Regarding meningioma, the results were as follows: for analogue phones, OR=1.3, 95% CI=0.99-1.7; for digital phones, OR=1.1, 95% CI=0.9-1.3; and for cordless phones, OR=1.1, 95% CI=0.9-1.4. In the multivariate analysis, a significantly increased risk of acoustic neuroma was found with the use of analogue phones. PMID:16391807

Hardell, Lennart; Carlberg, Michael; Hansson Mild, Kjell

2006-02-01

222

Interactions between pre-processing and classification methods for event-related-potential classification: best-practice guidelines for brain-computer interfacing.  

PubMed

Detecting event related potentials (ERPs) from single trials is critical to the operation of many stimulus-driven brain computer interface (BCI) systems. The low strength of the ERP signal compared to the noise (due to artifacts and BCI irrelevant brain processes) makes this a challenging signal detection problem. Previous work has tended to focus on how best to detect a single ERP type (such as the visual oddball response). However, the underlying ERP detection problem is essentially the same regardless of stimulus modality (e.g., visual or tactile), ERP component (e.g., P300 oddball response, or the error-potential), measurement system or electrode layout. To investigate whether a single ERP detection method might work for a wider range of ERP BCIs we compare detection performance over a large corpus of more than 50 ERP BCI datasets whilst systematically varying the electrode montage, spectral filter, spatial filter and classifier training methods. We identify an interesting interaction between spatial whitening and regularised classification which made detection performance independent of the choice of spectral filter low-pass frequency. Our results show that pipeline consisting of spectral filtering, spatial whitening, and regularised classification gives near maximal performance in all cases. Importantly, this pipeline is simple to implement and completely automatic with no expert feature selection or parameter tuning required. Thus, we recommend this combination as a "best-practice" method for ERP detection problems. PMID:23250668

Farquhar, J; Hill, N J

2013-04-01

223

Validation of the RTOG recursive partitioning analysis (RPA) classification for small-cell lung cancer-only brain metastases  

SciTech Connect

Purpose: Radiation Therapy Oncology Group (RTOG) developed a prognostic classification based on a recursive partitioning analysis (RPA) of patient pretreatment characteristics from three completed brain metastases randomized trials. Clinical trials for patients with brain metastases generally exclude small-cell lung cancer (SCLC) cases. We hypothesize that the RPA classes are valid in the setting of SCLC brain metastases. Methods and Materials: A retrospective review of 154 SCLC patients with brain metastases treated between April 1983 and May 2005 was performed. RPA criteria used for class assignment were Karnofsky performance status (KPS), primary tumor status (PT), presence of extracranial metastases (ED), and age. Results: Median survival was 4.9 months, with 4 patients (2.6%) alive at analysis. Median follow-up was 4.7 months (range, 0.3-40.3 months). Median age was 65 (range, 42-85 years). Median KPS was 70 (range, 40-100). Number of patients with controlled PT and no ED was 20 (13%) and with ED, 27 (18%); without controlled PT and ED, 34 (22%) and with ED, 73 (47%). RPA class distribution was: Class I: 8 (5%); Class II: 96 (62%); Class III: 51 (33%). Median survivals (in months) by RPA class were: Class I: 8.6; Class II: 4.2; Class III: 2.3 (p = 0.0023). Conclusions: Survivals for SCLC-only brain metastases replicate the results from the RTOG RPA classification. These classes are therefore valid for brain metastases from SCLC, support the inclusion of SCLC patients in future brain metastases trials, and may also serve as a basis for historical comparisons.

Videtic, Gregory M.M. [Department of Radiation Oncology, Cleveland Clinic Foundation, Cleveland, OH (United States)]. E-mail: videtig@ccf.org; Adelstein, David J. [Department of Medical Oncology, Cleveland Clinic Foundation, Cleveland, OH (United States); Mekhail, Tarek M. [Department of Medical Oncology, Cleveland Clinic Foundation, Cleveland, OH (United States); Rice, Thomas W. [Department of Thoracic Surgery, Cleveland Clinic Foundation, Cleveland, OH (United States); Stevens, Glen H.J. [Brain Tumor Institute, Cleveland Clinic Foundation, Cleveland, OH (United States); Lee, S.-Y. [Department of Radiation Oncology, Cleveland Clinic Foundation, Cleveland, OH (United States); Suh, John H. [Department of Radiation Oncology, Cleveland Clinic Foundation, Cleveland, OH (United States); Brain Tumor Institute, Cleveland Clinic Foundation, Cleveland, OH (United States)

2007-01-01

224

Case-control study of the association between malignant brain tumours diagnosed between 2007 and 2009 and mobile and cordless phone use.  

PubMed

Previous studies have shown a consistent association between long-term use of mobile and cordless phones and glioma and acoustic neuroma, but not for meningioma. When used these phones emit radiofrequency electromagnetic fields (RF-EMFs) and the brain is the main target organ for the handheld phone. The International Agency for Research on Cancer (IARC) classified in May, 2011 RF-EMF as a group 2B, i.e. a 'possible' human carcinogen. The aim of this study was to further explore the relationship between especially long-term (>10 years) use of wireless phones and the development of malignant brain tumours. We conducted a new case-control study of brain tumour cases of both genders aged 18-75 years and diagnosed during 2007-2009. One population-based control matched on gender and age (within 5 years) was used to each case. Here, we report on malignant cases including all available controls. Exposures on e.g. use of mobile phones and cordless phones were assessed by a self-administered questionnaire. Unconditional logistic regression analysis was performed, adjusting for age, gender, year of diagnosis and socio-economic index using the whole control sample. Of the cases with a malignant brain tumour, 87% (n=593) participated, and 85% (n=1,368) of controls in the whole study answered the questionnaire. The odds ratio (OR) for mobile phone use of the analogue type was 1.8, 95% confidence interval (CI)=1.04?3.3, increasing with >25 years of latency (time since first exposure) to an OR=3.3, 95% CI=1.6-6.9. Digital 2G mobile phone use rendered an OR=1.6, 95% CI=0.996-2.7, increasing with latency >15-20 years to an OR=2.1, 95% CI=1.2-3.6. The results for cordless phone use were OR=1.7, 95% CI=1.1-2.9, and, for latency of 15-20 years, the OR=2.1, 95% CI=1.2-3.8. Few participants had used a cordless phone for >20-25 years. Digital type of wireless phones (2G and 3G mobile phones, cordless phones) gave increased risk with latency >1-5 years, then a lower risk in the following latency groups, but again increasing risk with latency >15-20 years. Ipsilateral use resulted in a higher risk than contralateral mobile and cordless phone use. Higher ORs were calculated for tumours in the temporal and overlapping lobes. Using the meningioma cases in the same study as reference entity gave somewhat higher ORs indicating that the results were unlikely to be explained by recall or observational bias. This study confirmed previous results of an association between mobile and cordless phone use and malignant brain tumours. These findings provide support for the hypothesis that RF-EMFs play a role both in the initiation and promotion stages of carcinogenesis. PMID:24064953

Hardell, Lennart; Carlberg, Michael; Söderqvist, Fredrik; Mild, Kjell Hansson

2013-09-24

225

Brain machine interface: Classification of mental tasks using short-time PCA and recurrent neural networks  

Microsoft Academic Search

Brain machine interface provides a communication channel between the human brain and an external device. Brain interfaces are studied to provide rehabilitation to patients with neurodegenerative diseases; such patients loose all communication pathways except for their sensory and cognitive functions. One of the possible rehabilitation methods for these patients is to provide a brain machine interface (BMI) for communication, using

C. R. Hema; M. P. Paulraj; S. Yaacob; A. Hamid Adom; R. Nagarajan

2007-01-01

226

Molecular classification of brain tumor biopsies using solid-state magic angle spinning proton magnetic resonance spectroscopy and robust classifiers  

PubMed Central

Brain tumors are one of the leading causes of death in adults with cancer; however, molecular classification of these tumors with in vivo magnetic resonance spectroscopy (MRS) is limited because of the small number of metabolites detected. In vitro MRS provides highly informative biomarker profiles at higher fields, but also consumes the sample so that it is unavailable for subsequent analysis. In contrast, ex vivo high-resolution magic angle spinning (HRMAS) MRS conserves the sample but requires large samples and can pose technical challenges for producing accurate data, depending on the sample testing temperature. We developed a novel approach that combines a two-dimensional (2D), solid-state, HRMAS proton (1H) NMR method, TOBSY (total through-bond spectroscopy), which maximizes the advantages of HRMAS and a robust classification strategy. We used 2 mg of tissue at -8°C from each of 55 brain biopsies, and reliably detected 16 different molecules. We compared two classification strategies, the support vector machine (SVM) classifier and a feed-forward neural network using the Levenberg-Marquardt back-propagation algorithm. We used the minimum redundancy/maximum relevance (MRMR) method as a powerful feature-selection scheme along with the SVM classifier. We also used the minimum redundancy/maximum relevance (MRMR) method as a powerful feature-selection scheme along with the SVM classifier.

Andronesi, Ovidiu C.; Blekas, Konstantinos D.; Mintzopoulos, Dionyssios; Astrakas, Loukas; Black, Peter M.; Tzika, A. Aria

2008-01-01

227

Pattern classification of brain activation during emotional processing in subclinical depression: psychosis proneness as potential confounding factor  

PubMed Central

We used Support Vector Machine (SVM) to perform multivariate pattern classification based on brain activation during emotional processing in healthy participants with subclinical depressive symptoms. Six-hundred undergraduate students completed the Beck Depression Inventory II (BDI-II). Two groups were subsequently formed: (i) subclinical (mild) mood disturbance (n = 17) and (ii) no mood disturbance (n = 17). Participants also completed a self-report questionnaire on subclinical psychotic symptoms, the Community Assessment of Psychic Experiences Questionnaire (CAPE) positive subscale. The functional magnetic resonance imaging (fMRI) paradigm entailed passive viewing of negative emotional and neutral scenes. The pattern of brain activity during emotional processing allowed correct group classification with an overall accuracy of 77% (p = 0.002), within a network of regions including the amygdala, insula, anterior cingulate cortex and medial prefrontal cortex. However, further analysis suggested that the classification accuracy could also be explained by subclinical psychotic symptom scores (correlation with SVM weights r = 0.459, p = 0.006). Psychosis proneness may thus be a confounding factor for neuroimaging studies in subclinical depression.

Mechelli, Andrea; Pettersson-Yeo, William; Allen, Paul; McGuire, Philip; Aleman, Andre

2013-01-01

228

Pattern classification of brain activation during emotional processing in subclinical depression: psychosis proneness as potential confounding factor.  

PubMed

We used Support Vector Machine (SVM) to perform multivariate pattern classification based on brain activation during emotional processing in healthy participants with subclinical depressive symptoms. Six-hundred undergraduate students completed the Beck Depression Inventory II (BDI-II). Two groups were subsequently formed: (i) subclinical (mild) mood disturbance (n = 17) and (ii) no mood disturbance (n = 17). Participants also completed a self-report questionnaire on subclinical psychotic symptoms, the Community Assessment of Psychic Experiences Questionnaire (CAPE) positive subscale. The functional magnetic resonance imaging (fMRI) paradigm entailed passive viewing of negative emotional and neutral scenes. The pattern of brain activity during emotional processing allowed correct group classification with an overall accuracy of 77% (p = 0.002), within a network of regions including the amygdala, insula, anterior cingulate cortex and medial prefrontal cortex. However, further analysis suggested that the classification accuracy could also be explained by subclinical psychotic symptom scores (correlation with SVM weights r = 0.459, p = 0.006). Psychosis proneness may thus be a confounding factor for neuroimaging studies in subclinical depression. PMID:23638379

Modinos, Gemma; Mechelli, Andrea; Pettersson-Yeo, William; Allen, Paul; McGuire, Philip; Aleman, Andre

2013-02-26

229

Adrenal Tumours  

Microsoft Academic Search

Benign or malignant tumours within the adrenal glands can give rise to of a number of hypersecretion syndromes dependent on where the tumour is located. These include oversecretion of aldosterone (Conn syndrome), cortisol (Cushing syndrome) or androgens (androgenital syndrome) and adrenaline or noradrenaline (pheochromocytoma). It is very difficult to distinguish benign and malignant adrenocortical tumours. However, a number of criteria

L Jarolim; J Breza; H Wunderlich

2003-01-01

230

A comparison of classification techniques for a gaze-independent P300-based brain-computer interface  

NASA Astrophysics Data System (ADS)

This off-line study aims to assess the performance of five classifiers commonly used in the brain-computer interface (BCI) community, when applied to a gaze-independent P300-based BCI. In particular, we compared the results of four linear classifiers and one nonlinear: Fisher's linear discriminant analysis (LDA), stepwise linear discriminant analysis (SWLDA), Bayesian linear discriminant analysis (BLDA), linear support vector machine (LSVM) and Gaussian supported vector machine (GSVM). Moreover, different values for the decimation of the training dataset were tested. The results were evaluated both in terms of accuracy and written symbol rate with the data of 19 healthy subjects. No significant differences among the considered classifiers were found. The optimal decimation factor spanned a range from 3 to 24 (12 to 94 ms long bins). Nevertheless, performance on individually optimized classification parameters is not significantly different from a classification with general parameters (i.e. using an LDA classifier, about 48 ms long bins).

Aloise, F.; Schettini, F.; Aricò, P.; Salinari, S.; Babiloni, F.; Cincotti, F.

2012-08-01

231

Monitoring individual response to brain-tumour chemotherapy: proton MR spectroscopy in a patient with recurrent glioma after stereotactic radiotherapy.  

PubMed

Since antineoplastic activity varies, sensitive methods for individual assessment of efficacy are needed. We demonstrate the clinical value of MR spectroscopy in monitoring chemotherapy in a patient with recurrent glioma after stereotactic radiotherapy. Diagnostic imaging before and after chemotherapy included contrast-enhanced MRI, single-voxel proton MR spectroscopy ((1)H MRS), (1)H MR spectroscopic imaging ((1)H SI), and fluorodeoxyglucose (FDG) positron-emission tomography (PET). A significant decrease in choline signal intensity was observed 2 months after chemotherapy indicating tumour chemosensitivity, in line with tumour shrinkage on MRI and decreased uptake of FDG. Assessment of early response by MRS may help to improve treatment protocols in other patients. PMID:14685797

Lichy, M P; Bachert, P; Henze, M; Lichy, C M; Debus, J; Schlemmer, H P

2003-12-18

232

The colorectal tumour suppressor APC is present in the NMDA-receptor-PSD-95 complex in the brain  

Microsoft Academic Search

Background: The synaptic protein PSD-95\\/SAP90 interacts with ion channels such as the N-methyl-D- aspartate-receptor (NMDA-R) via its PDZ domain, and is involved in their clustering. Moreover, it interacts with signalling molecules and plays an important role in coupling NMDA-R to pathways that control synaptic plasticity and learning. Results: We report that PSD-95 interacts with the adenomatous polyposis coli (APC) tumour

Hiroyuki Yanai; Kiyotoshi Satoh; Akihiko Matsumine; Tetsu Akiyama

2000-01-01

233

Classification and Lateralization of Temporal Lobe Epilepsies with and without Hippocampal Atrophy Based on Whole-Brain Automatic MRI Segmentation  

PubMed Central

Brain images contain information suitable for automatically sorting subjects into categories such as healthy controls and patients. We sought to identify morphometric criteria for distinguishing controls (n?=?28) from patients with unilateral temporal lobe epilepsy (TLE), 60 with and 20 without hippocampal atrophy (TLE-HA and TLE-N, respectively), and for determining the presumed side of seizure onset. The framework employs multi-atlas segmentation to estimate the volumes of 83 brain structures. A kernel-based separability criterion was then used to identify structures whose volumes discriminate between the groups. Next, we applied support vector machines (SVM) to the selected set for classification on the basis of volumes. We also computed pairwise similarities between all subjects and used spectral analysis to convert these into per-subject features. SVM was again applied to these feature data. After training on a subgroup, all TLE-HA patients were correctly distinguished from controls, achieving an accuracy of 96 ± 2% in both classification schemes. For TLE-N patients, the accuracy was 86 ± 2% based on structural volumes and 91 ± 3% using spectral analysis. Structures discriminating between patients and controls were mainly localized ipsilaterally to the presumed seizure focus. For the TLE-HA group, they were mainly in the temporal lobe; for the TLE-N group they included orbitofrontal regions, as well as the ipsilateral substantia nigra. Correct lateralization of the presumed seizure onset zone was achieved using hippocampi and parahippocampal gyri in all TLE-HA patients using either classification scheme; in the TLE-N patients, lateralization was accurate based on structural volumes in 86 ± 4%, and in 94 ± 4% with the spectral analysis approach. Unilateral TLE has imaging features that can be identified automatically, even when they are invisible to human experts. Such morphometric image features may serve as classification and lateralization criteria. The technique also detects unsuspected distinguishing features like the substantia nigra, warranting further study.

Keihaninejad, Shiva; Heckemann, Rolf A.; Gousias, Ioannis S.; Hajnal, Joseph V.; Duncan, John S.; Aljabar, Paul; Rueckert, Daniel; Hammers, Alexander

2012-01-01

234

Identification of primary tumors of brain metastases by SIMCA classification of IR spectroscopic images  

Microsoft Academic Search

Brain metastases are secondary intracranial lesions which occur more frequently than primary brain tumors. The four most abundant types of brain metastasis originate from primary tumors of lung cancer, colorectal cancer, breast cancer and renal cell carcinoma. As metastatic cells contain the molecular information of the primary tissue cells and IR spectroscopy probes the molecular fingerprint of cells, IR spectroscopy

Christoph Krafft; Larysa Shapoval; Stephan B. Sobottka; Kathrin D. Geiger; Gabriele Schackert; Reiner Salzer

2006-01-01

235

Supervised classification of brain tissues through local multi-scale texture analysis by coupling DIR and FLAIR MR sequences  

NASA Astrophysics Data System (ADS)

The automatic segmentation of brain tissues in magnetic resonance (MR) is usually performed on T1-weighted images, due to their high spatial resolution. T1w sequence, however, has some major downsides when brain lesions are present: the altered appearance of diseased tissues causes errors in tissues classification. In order to overcome these drawbacks, we employed two different MR sequences: fluid attenuated inversion recovery (FLAIR) and double inversion recovery (DIR). The former highlights both gray matter (GM) and white matter (WM), the latter highlights GM alone. We propose here a supervised classification scheme that does not require any anatomical a priori information to identify the 3 classes, "GM", "WM", and "background". Features are extracted by means of a local multi-scale texture analysis, computed for each pixel of the DIR and FLAIR sequences. The 9 textures considered are average, standard deviation, kurtosis, entropy, contrast, correlation, energy, homogeneity, and skewness, evaluated on a neighborhood of 3x3, 5x5, and 7x7 pixels. Hence, the total number of features associated to a pixel is 56 (9 textures x3 scales x2 sequences +2 original pixel values). The classifier employed is a Support Vector Machine with Radial Basis Function as kernel. From each of the 4 brain volumes evaluated, a DIR and a FLAIR slice have been selected and manually segmented by 2 expert neurologists, providing 1st and 2nd human reference observations which agree with an average accuracy of 99.03%. SVM performances have been assessed with a 4-fold cross-validation, yielding an average classification accuracy of 98.79%.

Poletti, Enea; Veronese, Elisa; Calabrese, Massimiliano; Bertoldo, Alessandra; Grisan, Enrico

2012-02-01

236

Real-time classification of activated brain areas for fMRI-based human-brain-interfaces  

Microsoft Academic Search

Functional MR imaging (fMRI) enables to detect different activated brain areas according to the performed tasks. However, data are usually evaluated after the experiment, which prohibits intra-experiment optimization or more sophisticated applications such as biofeedback experiments. Using a human-brain-interface (HBI), subjects are able to communicate with external programs, e.g. to navigate through virtual scenes, or to experience and modify their

Tobias Moench; Maurice Hollmann; Ramona Grzeschik; Charles Mueller; Ralf Luetzkendorf; Sebastian Baecke; Michael Luchtmann; Daniela Wagegg; Johannes Bernarding

2008-01-01

237

Canadian Study of Determinants of Endometabolic Health in ChIlDrEn (CanDECIDE study): a cohort study protocol examining the mechanisms of obesity in survivors of childhood brain tumours  

PubMed Central

Background Childhood obesity has reached epidemic proportions and is impacting children's health globally. In adults, obesity is associated with chronic low-grade inflammation that leads to insulin resistance, which is one of the important mechanisms through which dysregulation of metabolism occurs. There is limited information available about the contribution of inflammation to metabolic health in obese children, and how individual and lifestyle factors impact this risk. One of the paediatric groups at risk of higher rates of obesity includes the survivors of childhood brain tumours. The aim of this study was to evaluate the mechanisms that contribute to inflammation in obese survivors of childhood brain tumours. Methods and analysis This is a prospective cohort study. We will recruit lean and obese survivors of childhood brain tumours, and a control group composed of lean and obese children with no history of tumours. We will measure circulating and urinary cytokine levels and cytokine gene expression in monocytes. In addition, the methylation patterns of cytokine genes and that of toll-like receptor genes will be evaluated. These will be correlated with individual and lifestyle factors including age, sex, ethnicity, puberty, body mass index, fasting lipid levels, insulin sensitivity, diet, exercise, sleep, stress and built environment. The sample size calculation showed that we need 25 participants per arm Ethics and dissemination This study has received ethics approval from the institutional review board. Once completed, we will publish this work in peer-reviewed journals and share the findings in presentations and posters in meetings. Discussion This study will permit the interrogation of inflammation as a contributor to obesity and its complications in obese survivors of childhood brain tumours and compare them with lean survivors and lean and obese controls with no history of tumours, which may help identify therapeutic and preventative interventions to combat the rising tide of obesity.

Samaan, M Constantine; Thabane, Lehana; Burrow, Sarah; Dillenburg, Rejane F; Scheinemann, Katrin

2013-01-01

238

Classification of Biopsy-Confirmed Brain Tumors Using Single-Voxel MR Spectroscopy  

Microsoft Academic Search

BACKGROUND AND PURPOSE: Our purpose was to develop a classification scheme and method of presentation of in vivo single-voxel proton spectroscopic data from astrocytomas that most closely match the classification scheme determined from biopsy specimens. Since in vivo proton spectroscopy is noninvasive, it may be an attractive alternative to intracranial biopsy. METHODS: Single-voxel spectra were acquired using the point-resolved spectroscopic

M. Elizabeth Meyerand; J. Marc Pipas; Alex Mamourian; Tor D. Tosteson; Jeffery F. Dunn

1999-01-01

239

Preliminary data on classification of normal and brain-damaged elderly subjects  

Microsoft Academic Search

Classification of “normal” or “impaired” performance using conventional neuropsychological cut-off scores was studied in a sample of 134 normal subjects, and 94 subjects with independently confirmed cerebral damage. Conventional cut-off scores misclassified a large percentage of normal subjects as impaired. Based on raw score distributions, cut-off scores were identified which markedly improved the correct classification rates for normals. Similar analyses

R. A. Bornstein; C. Paniak; W. Obrien

1987-01-01

240

New Zealand adolescents' cellphone and cordless phone user-habits: are they at increased risk of brain tumours already? A cross-sectional study  

PubMed Central

Background Cellphone and cordless phone use is very prevalent among early adolescents, but the extent and types of use is not well documented. This paper explores how, and to what extent, New Zealand adolescents are typically using and exposed to active cellphones and cordless phones, and considers implications of this in relation to brain tumour risk, with reference to current research findings. Methods This cross-sectional study recruited 373 Year 7 and 8 school students with a mean age of 12.3 years (range 10.3-13.7 years) from the Wellington region of New Zealand. Participants completed a questionnaire and measured their normal body-to-phone texting distances. Main exposure-metrics included self-reported time spent with an active cellphone close to the body, estimated time and number of calls on both phone types, estimated and actual extent of SMS text-messaging, cellphone functions used and people texted. Statistical analyses used Pearson Chi2 tests and Pearson’s correlation coefficient (r). Analyses were undertaken using SPSS version 19.0. Results Both cellphones and cordless phones were used by approximately 90% of students. A third of participants had already used a cordless phone for ? 7 years. In 4 years from the survey to mid-2013, the cordless phone use of 6% of participants would equal that of the highest Interphone decile (? 1640 hours), at the surveyed rate of use. High cellphone use was related to cellphone location at night, being woken regularly, and being tired at school. More than a third of parents thought cellphones carried a moderate-to-high health risk for their child. Conclusions While cellphones were very popular for entertainment and social interaction via texting, cordless phones were most popular for calls. If their use continued at the reported rate, many would be at increased risk of specific brain tumours by their mid-teens, based on findings of the Interphone and Hardell-group studies.

2013-01-01

241

Pooled analysis of case-control studies on malignant brain tumours and the use of mobile and cordless phones including living and deceased subjects.  

PubMed

We studied the association between use of mobile and cordless phones and malignant brain tumours. Pooled analysis was performed of two case-control studies on patients with malignant brain tumours diagnosed during 1997-2003 and matched controls alive at the time of study inclusion and one case-control study on deceased patients and controls diagnosed during the same time period. Cases and controls or relatives to deceased subjects were interviewed using a structured questionnaire. Replies were obtained for 1,251 (85%) cases and 2,438 (84%) controls. The risk increased with latency period and cumulative use in hours for both mobile and cordless phones. Highest risk was found for the most common type of glioma, astrocytoma, yielding in the >10 year latency group for mobile phone use odds ratio (OR) = 2.7, 95% confidence interval (CI) = 1.9-3.7 and cordless phone use OR = 1.8, 95% CI = 1.2-2.9. In a separate analysis, these phone types were independent risk factors for glioma. The risk for astrocytoma was highest in the group with first use of a wireless phone before the age of 20; mobile phone use OR = 4.9, 95% CI = 2.2-11, cordless phone use OR = 3.9, 95% CI = 1.7-8.7. In conclusion, an increased risk was found for glioma and use of mobile or cordless phone. The risk increased with latency time and cumulative use in hours and was highest in subjects with first use before the age of 20. PMID:21331446

Hardell, Lennart; Carlberg, Michael; Hansson Mild, Kjell

2011-02-17

242

Neuroendocrine Tumours of the Breast  

Microsoft Academic Search

\\u000a There is debate about the existence of neuroendocrine cells in the normal breast, however, tumours with varying degrees of\\u000a neuroendocrine differentiation occur. The latest WHO classification identifies solid neuroendocrine carcinoma, small and large\\u000a cell carcinoma. In addition mucinous carcinoma contributes to a large number of tumours with neuroendocrine differentiation.\\u000a The biology and molecular pathology of solid neuroendocrine and mucinous carcinomas

Andrew M. Hanby; Rebecca A. Brannan

243

Prediction of passive blood-brain partitioning: straightforward and effective classification models based on in silico derived physicochemical descriptors  

PubMed Central

The distribution of compounds between blood and brain is a very important consideration for new candidate drug molecules. In this paper, we describe the derivation of two linear discriminant analysis (LDA) models for the prediction of passive blood-brain partitioning, expressed in terms of log BB values. The models are based on computationally derived physicochemical descriptors, namely the octanol/water partition coefficient (log P), the topological polar surface area (TPSA) and the total number of acidic and basic atoms, and were obtained using a homogeneous training set of 307 compounds, for all of which the published experimental log BB data had been determined in vivo. In particular, since molecules with log BB > 0.3 cross the blood-brain barrier (BBB) readily while molecules with log BB < ?1 are poorly distributed to the brain, on the basis of these thresholds we derived two distinct models, both of which show a percentage of good classification of about 80%. Notably, the predictive power of our models was confirmed by the analysis of a large external dataset of compounds with reported activity on the central nervous system (CNS) or lack thereof. The calculation of straightforward physicochemical descriptors is the only requirement for the prediction of the log BB of novel compounds through our models, which can be conveniently applied in conjunction with drug design and virtual screenings.

Vilar, Santiago; Chakrabarti, Mayukh; Costanzi, Stefano

2010-01-01

244

Overcoming fear and anxiety during awake resection of brain tumours: family support can be pivotal to a successful outcome.  

PubMed

Patient anxiety and fear about an awake craniotomy can affect the patient's choice about having an operation despite comprehensive pre-operative counselling. We report three cases in which a family member came into theatre during the procedure to support the patient during surgery. All three cases, which involved intra-operative cortical and subcortical stimulations and intra-operative patient testing, were successfully completed with major tumour resections and no post-operative complications. We suggest that family support should be considered in patients who have extreme fear and anxiety about awake surgery. PMID:22894659

Whittle, Ian R; Lim, Jia X

2012-08-15

245

Classification of wheelchair commands using brain computer interface: comparison between able-bodied persons and patients with tetraplegia.  

PubMed

This paper presents a three-class mental task classification for an electroencephalography based brain computer interface. Experiments were conducted with patients with tetraplegia and able bodied controls. In addition, comparisons with different time-windows of data were examined to find the time window with the highest classification accuracy. The three mental tasks used were letter composing, arithmetic and imagery of a Rubik's cube rolling forward; these tasks were associated with three wheelchair commands: left, right and forward, respectively. An eyes closed task was also recorded for the algorithms testing and used as an additional on/off command. The features extraction method was based on the spectrum from a Hilbert-Huang transform and the classification algorithm was based on an artificial neural network with a fuzzy particle swarm optimization with cross-mutated operation. The results show a strong eyes closed detection for both groups with average accuracy at above 90%. The overall result for the combined groups shows an improved average accuracy of 70.6% at 1s, 74.8% at 2s, 77.8% at 3s, 79.6% at 4s and 81.4% at 5s. The accuracy for individual groups were lower for patients with tetraplegia compared to the able-bodied group, however, does improve with increased duration of the time-window. PMID:24109856

Chai, Rifai; Ling, Sai Ho; Hunter, Gregory P; Tran, Yvonne; Nguyen, Hung T

2013-07-01

246

Biophysical models of tumour growth  

NASA Astrophysics Data System (ADS)

Tumour growth is a multifactorial process, which has stimulated in recent decades the development of numerous models trying to figure out the mechanisms controlling solid tumours morphogenesis. While the earliest models were focusing on cell proliferation kinetics, modulated by the availability of supplied nutrients, new modelling approaches emphasize the crucial role of several biophysical processes, including local matrix remodelling, active cell migration and traction, and reshaping of host tissue vasculature. After a brief presentation of this experimental background, this review will outline a number of representative models describing, at different scales, the growth of avascular and vascularized tumours. Special attention will be paid to the formulation of tumour-host tissue interactions that selectively drive changes in tumour size and morphology, and which are notably mediated by the mechanical status and elasticity of the tumour microenvironment. Emergence of invasive behaviour through growth instabilities at the tumour-host interface will be presented considering both reaction-diffusion and mechano-cellular models. In the latter part of the review, patient-oriented implications of tumour growth modelling are outlined in the context of brain tumours. Some conceptual views of the adaptive strategies and selective barriers that govern tumour evolution are presented in conclusion as potential guidelines for the development of future models.

Tracqui, P.

2009-05-01

247

The value of tumour spread, grading and growth pattern as morphological predictive parameters in bladder carcinoma. A critical revision of the 1987 TNM classification  

Microsoft Academic Search

A group of 343 patients with bladder carcinomas was uniformly staged, both clinico-radiologically and pathologically. In accordance with pathological staging, they were treated from 1983 to 1990 and follow-up was closed on January 1992. No systemic chemotherapy regime was used. The present study was designed to assess the value of classical morphological parameters (tumour extension, histological subtype, grade and growth

Javier C. Angulo; Jose I. Lopez; Nicolas Flores; Juan D. Toledo

1993-01-01

248

In vivo PET evaluation in tumour-bearing rats of 2-[18F]fluoromethyl-L-phenylalanine as a new potential tracer for molecular imaging of brain and extra-cranial tumours in humans with PET  

NASA Astrophysics Data System (ADS)

The Na+-independent L-type LAT1 amino acid transport system for large and neutral amino acids has been shown to be expressed higher in tumour tissue relative to normal tissue and has been regarded as a key point for the development of new amino acid based tumour tracers for molecular imaging. We developed a new fluorinated phenylalanine analogue, 2-[18F]fluoromethyl-L-phenylalanine, considering that the spatial volume of FCH3 is comparable with that of the iodine atom in 2-I-L-phenylalanine, of which we have proven that it is taken up excellently in tumours by the LAT1 system. The substrate molecule for radiolabeling, Boc-2-bromomethyl-L-phenylalanine-tButylester, was prepared by radical bromination of Boc-2-methyl-L-phenylalanine-tButylester. [18F-] for bromine exchange is performed within 3 min in conditions comparable to the [18F]FDG synthesis with a radiochemical yield of at least 85%. After deprotection and semi-preparative HPLC purification, the 2-[18F]fluoromethyl-L-phenylalanine is recovered n.c.a. (57%) with a high purity and 3.7 MBq were injected into R1M rhabdomyosarcoma tumour-bearing rats. Imaging was performed with a human PET camera from 5 to 45 min p.i. The tumour/background and tumour/blood ratios obtained from PET acquisition were at least 2.5. DUR values for the tumours were at least about 5. Furthermore, a small tumour implanted near a kidney could be well visualized completely separated from this kidney. Moreover in all tumours the “active” tumour tissue can clearly be differentiated from less active tumour tissue. This proves that 2-[18F]fluoromethyl-L-phenylalanine has a great potential as a new tracer for specific tumour diagnosis with PET.

Kersemans, Ken; Bauwens, Matthias; Lahoutte, Tony; Bossuyt, Axel; Mertens, John

2007-02-01

249

Tumours of the thymus  

PubMed Central

Eighty-eight cases of thymoma are discussed with the object of trying to co-ordinate the histological and clinical features. The pathological specimens were in all cases obtained at operation. The pathology classification introduced by Thomson and Thackray in 1957 has been found to correspond adequately with the clinical pattern. The most common groups of tumours are basically epithelial and can be separated into five or six subdivisions, each of which has a separate pattern of behaviour. Lymphoid and teratomatous tumours also occur, but there were only two examples in this series. Clinically, separation of patients who suffered from myasthenia (38) and those who did not (50) affords the first main grouping. The majority of patients who had myasthenia gravis had tumours classified as epidermoid (19) and lymphoepithelial (14), the former with a more malignant appearance and behaviour than the latter. Removal of the tumour with or without radiation gave considerable and sometimes complete relief from myasthenic symptoms. Non-myasthenic thymoma (50) was usually discovered as a result of pressure signs or in the course of routine radiography. Spindle or oval celled tumours followed a benign pattern whereas undifferentiated thymoma was in every sense malignant, as also were teratomatous growths. Granulomatous or Hodgkin-like thymomas were of special interest and had an unpredictable course, some patients surviving many years after what was regarded as inadequate treatment. The place of radiotherapy as a pre- or post-operative agent complementary to surgery is discussed. Images

Sellors, T. Holmes; Thackray, A. C.; Thomson, A. D.

1967-01-01

250

Classification of Motor Imaginary Signals for Machine Commmunication - A Novel Approach for Brain Machine Interface Design  

Microsoft Academic Search

A great interest for brain machine interface (BMI) is in the arising nowadays, instigated by several promising scientific and technological outcomes. The methods of measuring, processing and classifying brain activities, in order to interpret neuronal signals into machine control is often regarded as a challenging possibility as the expected beneficiaries are patients affected by motor disorders and paralyses. Aiming at

Vickneswaran Jeyabalan; Samraj Andrews; Chu Kiong Loo

2009-01-01

251

Single trial motor imagery classification for a four state brain machine interface  

Microsoft Academic Search

Motor imagery is the mental simulation of a motor act which can be used to design brain machine interfaces [BMI]. A BMI is a digital communication system, which connects the human brain directly to an external device bypassing the peripheral nervous system and muscular system. Thus a BMI opens up possibilities for a new communication channel for people with neuromuscular

C. R. Hema; M. P. Paulraj; S. Yaacob; A. H. Adom; R. Nagarajan

2009-01-01

252

Fuzzy Based Classification of EEG Mental Tasks for a Brain Machine Interface  

Microsoft Academic Search

Patients with neurodegenerative diseases loose all motor movements including impairment of speech, leaving the patients totally locked-in. One possible option for rehabilitation of such patients is using a brain machine interfaces (BMI) which uses their active cognition capabilities to control external devices and their environment. BMIs are designed using the electrical activity of the brain detected by scalp EEG electrodes.

C. R. Hema; M. P. Paulraj; R. Nagarajan; S. Yaacob; A. H. Adorn

2007-01-01

253

Brain classification reveals the right cerebellum as the best biomarker of dyslexia  

PubMed Central

Background Developmental dyslexia is a specific cognitive disorder in reading acquisition that has genetic and neurological origins. Despite histological evidence for brain differences in dyslexia, we recently demonstrated that in large cohort of subjects, no differences between control and dyslexic readers can be found at the macroscopic level (MRI voxel), because of large variances in brain local volumes. In the present study, we aimed at finding brain areas that most discriminate dyslexic from control normal readers despite the large variance across subjects. After segmenting brain grey matter, normalizing brain size and shape and modulating the voxels' content, normal readers' brains were used to build a 'typical' brain via bootstrapped confidence intervals. Each dyslexic reader's brain was then classified independently at each voxel as being within or outside the normal range. We used this simple strategy to build a brain map showing regional percentages of differences between groups. The significance of this map was then assessed using a randomization technique. Results The right cerebellar declive and the right lentiform nucleus were the two areas that significantly differed the most between groups with 100% of the dyslexic subjects (N = 38) falling outside of the control group (N = 39) 95% confidence interval boundaries. The clinical relevance of this result was assessed by inquiring cognitive brain-based differences among dyslexic brain subgroups in comparison to normal readers' performances. The strongest difference between dyslexic subgroups was observed between subjects with lower cerebellar declive (LCD) grey matter volumes than controls and subjects with higher cerebellar declive (HCD) grey matter volumes than controls. Dyslexic subjects with LCD volumes performed worse than subjects with HCD volumes in phonologically and lexicon related tasks. Furthermore, cerebellar and lentiform grey matter volumes interacted in dyslexic subjects, so that lower and higher lentiform grey matter volumes compared to controls differently modulated the phonological and lexical performances. Best performances (observed in controls) corresponded to an optimal value of grey matter and they dropped for higher or lower volumes. Conclusion These results provide evidence for the existence of various subtypes of dyslexia characterized by different brain phenotypes. In addition, behavioural analyses suggest that these brain phenotypes relate to different deficits of automatization of language-based processes such as grapheme/phoneme correspondence and/or rapid access to lexicon entries.

Pernet, Cyril R; Poline, Jean Baptiste; Demonet, Jean Francois; Rousselet, Guillaume A

2009-01-01

254

Aged-related changes in brain activity classification with respect to age by means of graph indexes.  

PubMed

Recent studies have investigated changes in the human brain network organization during the normal aging. A reduction of the connectivity between brain areas was demonstrated by combining neuroimaging technologies and graph theory. Clustering, characteristic path length and small-worldness are key topological measures and they are widely used in literature. In this paper we propose a new methodology that combine advanced techniques of effective connectivity estimation, graph theoretical approach and classification by SVM method. EEG signals recording during rest condition from 20 young subjects and 20 mid-aged adults were studied. Partial Directed Coherence was computed by means of General Linear Kalman Filter and graph indexes were extracted from estimated patterns. At last small-worldness was used as feature for the SVM classifier. Results show that topological differences of brain networks exist between young and mid-aged adults: small-worldness is significantly different between the two populations and it can be used to classify the subjects with respect to age with an accuracy of 69%. PMID:24110696

Petti, M; Toppi, J; Pichiorri, F; Cincotti, F; Salinari, S; Babiloni, F; Astolfi, L; Mattia, D

2013-07-01

255

Outcome Classification of Preschool Children With Autism Spectrum Disorders Using MRI Brain Measures  

Microsoft Academic Search

ObjectiveTo test the hypothesis that a combination of magnetic resonance imaging (MRI) brain measures obtained during early childhood distinguish children with autism spectrum disorders (ASD) from typically developing children and is associated with functional outcome.

Natacha Akshoomoff; Catherine Lord; Alan J. Lincoln; Rachel Y. Courchesne; Ruth A. Carper; Jeanne Townsend; Eric Courchesne

2004-01-01

256

Tumours of the liver and biliary system  

PubMed Central

In this histological classification of liver and gall bladder tumours the tumour types largely correspond to those found in man. The most common tumours in this group are liver cell adenoma, hepatocellular carcinoma, and cholangiocarcinoma. ImagesFig. 5Fig. 6Fig. 7Fig. 8Fig. 13Fig. 14Fig. 1Fig. 2Fig. 3Fig. 4Fig. 9Fig. 10Fig. 11Fig. 12

Ponomarkov, V.; Mackey, L. J.

1976-01-01

257

Classification of traumatic brain injury severity using informed data reduction in a series of binary classifier algorithms.  

PubMed

Assessment of medical disorders is often aided by objective diagnostic tests which can lead to early intervention and appropriate treatment. In the case of brain dysfunction caused by head injury, there is an urgent need for quantitative evaluation methods to aid in acute triage of those subjects who have sustained traumatic brain injury (TBI). Current clinical tools to detect mild TBI (mTBI/concussion) are limited to subjective reports of symptoms and short neurocognitive batteries, offering little objective evidence for clinical decisions; or computed tomography (CT) scans, with radiation-risk, that are most often negative in mTBI. This paper describes a novel methodology for the development of algorithms to provide multi-class classification in a substantial population of brain injured subjects, across a broad age range and representative subpopulations. The method is based on age-regressed quantitative features (linear and nonlinear) extracted from brain electrical activity recorded from a limited montage of scalp electrodes. These features are used as input to a unique "informed data reduction" method, maximizing confidence of prospective validation and minimizing over-fitting. A training set for supervised learning was used, including: "normal control," "concussed," and "structural injury/CT positive (CT+)." The classifier function separating CT+ from the other groups demonstrated a sensitivity of 96% and specificity of 78%; the classifier separating "normal controls" from the other groups demonstrated a sensitivity of 81% and specificity of 74%, suggesting high utility of such classifiers in acute clinical settings. The use of a sequence of classifiers where the desired risk can be stratified further supports clinical utility. PMID:22855231

Prichep, Leslie S; Jacquin, Arnaud; Filipenko, Julie; Dastidar, Samanwoy Ghosh; Zabele, Stephen; Vodencarevi?, Asmir; Rothman, Neil S

2012-07-26

258

Topology-corrected segmentation and local intensity estimates for improved partial volume classification of brain cortex in MRI.  

PubMed

In magnetic resonance imaging (MRI), accuracy and precision with which brain structures may be quantified are frequently affected by the partial volume (PV) effect. PV is due to the limited spatial resolution of MRI compared to the size of anatomical structures. Accurate classification of mixed voxels and correct estimation of the proportion of each pure tissue (fractional content) may help to increase the precision of cortical thickness estimation in regions where this measure is particularly difficult, such as deep sulci. The contribution of this work is twofold: on the one hand, we propose a new method to label voxels and compute tissue fractional content, integrating a mechanism for detecting sulci with topology preserving operators. On the other hand, we improve the computation of the fractional content of mixed voxels using local estimation of pure tissue intensity means. Accuracy and precision were assessed using simulated and real MR data and comparison with other existing approaches demonstrated the benefits of our method. Significant improvements in gray matter (GM) classification and cortical thickness estimation were brought by the topology correction. The fractional content root mean squared error diminished by 6.3% (p<0.01) on simulated data. The reproducibility error decreased by 8.8% (p<0.001) and the Jaccard similarity measure increased by 3.5% on real data. Furthermore, compared with manually guided expert segmentations, the similarity measure was improved by 12.0% (p<0.001). Thickness estimation with the proposed method showed a higher reproducibility compared with the measure performed after partial volume classification using other methods. PMID:20193712

Rueda, Andrea; Acosta, Oscar; Couprie, Michel; Bourgeat, Pierrick; Fripp, Jurgen; Dowson, Nicholas; Romero, Eduardo; Salvado, Olivier

2010-03-01

259

WAIS Digit Span-Based Indicators of Malingered Neurocognitive Dysfunction: Classification Accuracy in Traumatic Brain Injury  

ERIC Educational Resources Information Center

|The present study determined specificity and sensitivity to malingered neurocognitive dysfunction (MND) in traumatic brain injury (TBI) for several Wechsler Adult Intelligence Scale (WAIS) Digit Span scores. TBI patients (n = 344) were categorized into one of five groups: no incentive, incentive only, suspect, probable MND, and definite MND.…

Heinly, Matthew T.; Greve, Kevin W.; Bianchini, Kevin J.; Love, Jeffrey M.; Brennan, Adrianne

2005-01-01

260

Automatic segmentation of brain MR images using an adaptive balloon snake model with fuzzy classification.  

PubMed

Skull-stripping in magnetic resonance (MR) images is one of the most important preprocessing steps in medical image analysis. We propose a hybrid skull-stripping algorithm based on an adaptive balloon snake (ABS) model. The proposed framework consists of two phases: first, the fuzzy possibilistic c-means (FPCM) is used for pixel clustering, which provides a labeled image associated with a clean and clear brain boundary. At the second stage, a contour is initialized outside the brain surface based on the FPCM result and evolves under the guidance of an adaptive balloon snake model. The model is designed to drive the contour in the inward normal direction to capture the brain boundary. The entire volume is segmented from the center slice toward both ends slice by slice. Our ABS algorithm was applied to numerous brain MR image data sets and compared with several state-of-the-art methods. Four similarity metrics were used to evaluate the performance of the proposed technique. Experimental results indicated that our method produced accurate segmentation results with higher conformity scores. The effectiveness of the ABS algorithm makes it a promising and potential tool in a wide variety of skull-stripping applications and studies. PMID:23744446

Liu, Hung-Ting; Sheu, Tony W H; Chang, Herng-Hua

2013-06-07

261

Motion classification by epidural potential measurement of rat for low-invasive brain-machine interface  

Microsoft Academic Search

A low-invasive method to record neural activity is required for safe and practical brain-machine interfaces (BMI). BMIs are expected to be used to reintegrate motor functions of physically disabled persons; however, conventional invasive methods require electrodes inside the dura mater. In this study, the authors used epidural electrodes, which are located between the skull and dura mater, to record rat

Takeshi Uejima; Toshiyuki Fujii; Hiroshi Yokoi; Masatoshi Takita

2009-01-01

262

Outcome Classification of Preschool Children with Autism Spectrum Disorders Using Mri Brain Measures.  

ERIC Educational Resources Information Center

Objective: To test the hypothesis that a combination of magnetic resonance imaging (MRI) brain measures obtained during early childhood distinguish children with autism spectrum disorders (ASD) from typically developing children and is associated with functional outcome. Method: Quantitative MRI technology was used to measure gray and white matter…

Akshoomoff, Natacha; Lord, Catherine; Lincoln, Alan J.; Courchesne, Rachel Y.; Carper, Ruth A.; Townsend, Jeanne; Courchesne, Eric

2004-01-01

263

WAIS Digit Span-Based Indicators of Malingered Neurocognitive Dysfunction: Classification Accuracy in Traumatic Brain Injury  

ERIC Educational Resources Information Center

The present study determined specificity and sensitivity to malingered neurocognitive dysfunction (MND) in traumatic brain injury (TBI) for several Wechsler Adult Intelligence Scale (WAIS) Digit Span scores. TBI patients (n = 344) were categorized into one of five groups: no incentive, incentive only, suspect, probable MND, and definite MND.…

Heinly, Matthew T.; Greve, Kevin W.; Bianchini, Kevin J.; Love, Jeffrey M.; Brennan, Adrianne

2005-01-01

264

Atlas Guided Identification of Brain Structures by Combining 3D Segmentation and SVM Classification  

Microsoft Academic Search

This study presents a novel automatic approach for the iden- tification of anatomical brain structures in magnetic resonance images (MRI). The method combines a fast multiscale multi-channel three di- mensional (3D) segmentation algorithm providing a rich feature vocab- ulary together with a support vector machine (SVM) based classifier. The segmentation produces a full hierarchy of segments, expressed by an irregular

Ayelet Akselrod-ballin; Meirav Galun; Moshe John Gomori; Ronen Basri; Achi Brandt

2006-01-01

265

Classification of Imagined Beats for use in a Brain Computer Interface  

Microsoft Academic Search

The power spectrum of an EEG signal shows differences with respect to its baseline the moment a subject is hearing, or expecting, a tone. As this difference also occurs when one is not actually hearing it, a Brain Computer Interface can be developed in which imagined rhythms are used to transfer information. Four healthy subjects participated in this study in

Bas J. de Kruif; Rebecca Schaefer; Peter Desain

2007-01-01

266

Support vector machine classification and characterization of age-related reorganization of functional brain networks.  

PubMed

Most of what is known about the reorganization of functional brain networks that accompanies normal aging is based on neuroimaging studies in which participants perform specific tasks. In these studies, reorganization is defined by the differences in task activation between young and old adults. However, task activation differences could be the result of differences in task performance, strategy, or motivation, and not necessarily reflect reorganization. Resting-state fMRI provides a method of investigating functional brain networks without such confounds. Here, a support vector machine (SVM) classifier was used in an attempt to differentiate older adults from younger adults based on their resting-state functional connectivity. In addition, the information used by the SVM was investigated to see what functional connections best differentiated younger adult brains from older adult brains. Three separate resting-state scans from 26 younger adults (18-35 yrs) and 26 older adults (55-85) were obtained from the International Consortium for Brain Mapping (ICBM) dataset made publically available in the 1000 Functional Connectomes project www.nitrc.org/projects/fcon_1000. 100 seed-regions from four functional networks with 5mm(3) radius were defined based on a recent study using machine learning classifiers on adolescent brains. Time-series for every seed-region were averaged and three matrices of z-transformed correlation coefficients were created for each subject corresponding to each individual's three resting-state scans. SVM was then applied using leave-one-out cross-validation. The SVM classifier was 84% accurate in classifying older and younger adult brains. The majority of the connections used by the classifier to distinguish subjects by age came from seed-regions belonging to the sensorimotor and cingulo-opercular networks. These results suggest that age-related decreases in positive correlations within the cingulo-opercular and default networks, and decreases in negative correlations between the default and sensorimotor networks, are the distinguishing characteristics of age-related reorganization. PMID:22227886

Meier, Timothy B; Desphande, Alok S; Vergun, Svyatoslav; Nair, Veena A; Song, Jie; Biswal, Bharat B; Meyerand, Mary E; Birn, Rasmus M; Prabhakaran, Vivek

2011-12-28

267

Distributed effects of methylphenidate on the network structure of the resting brain: a connectomic pattern classification analysis.  

PubMed

Methylphenidate is a psychostimulant medication that produces improvements in functions associated with multiple neurocognitive systems. To investigate the potentially distributed effects of methylphenidate on the brain's intrinsic network architecture, we coupled resting state imaging with multivariate pattern classification. In a within-subject, double-blind, placebo-controlled, randomized, counterbalanced, cross-over design, 32 healthy human volunteers received either methylphenidate or placebo prior to two fMRI resting state scans separated by approximately one week. Resting state connectomes were generated by placing regions of interest at regular intervals throughout the brain, and these connectomes were submitted for support vector machine analysis. We found that methylphenidate produces a distributed, reliably detected, multivariate neural signature. Methylphenidate effects were evident across multiple resting state networks, especially visual, somatomotor, and default networks. Methylphenidate reduced coupling within visual and somatomotor networks. In addition, default network exhibited decoupling with several task positive networks, consistent with methylphenidate modulation of the competitive relationship between these networks. These results suggest that connectivity changes within and between large-scale networks are potentially involved in the mechanisms by which methylphenidate improves attention functioning. PMID:23684862

Sripada, Chandra Sekhar; Kessler, Daniel; Welsh, Robert; Angstadt, Michael; Liberzon, Israel; Phan, K Luan; Scott, Clayton

2013-05-16

268

Brain tissue classification based on DTI using an improved Fuzzy C-means algorithm with spatial constraints.  

PubMed

We present an effective method for brain tissue classification based on diffusion tensor imaging (DTI) data. The method accounts for two main DTI segmentation obstacles: random noise and magnetic field inhomogeneities. In the proposed method, DTI parametric maps were used to resolve intensity inhomogeneities of brain tissue segmentation because they could provide complementary information for tissues and define accurate tissue maps. An improved fuzzy c-means with spatial constraints proposal was used to enhance the noise and artifact robustness of DTI segmentation. Fuzzy c-means clustering with spatial constraints (FCM_S) could effectively segment images corrupted by noise, outliers, and other imaging artifacts. Its effectiveness contributes not only to the introduction of fuzziness for belongingness of each pixel but also to the exploitation of spatial contextual information. We proposed an improved FCM_S applied on DTI parametric maps, which explores the mean and covariance of the feature spatial information for automated segmentation of DTI. The experiments on synthetic images and real-world datasets showed that our proposed algorithms, especially with new spatial constraints, were more effective. PMID:23891435

Wen, Ying; He, Lianghua; von Deneen, Karen M; Lu, Yue

2013-07-25

269

Identification and characterisation of childhood cerebellar tumours by in vivo proton MRS.  

PubMed

(1)H MRS has great potential for the clinical investigation of childhood brain tumours, but the low incidence in, and difficulties of performing trials on, children have hampered progress in this area. Most studies have used a long-TE, thus limiting the metabolite information obtained, and multivariate analysis has been largely unexplored. Thirty-five children with untreated cerebellar tumours (18 medulloblastomas, 12 pilocytic astrocytomas and five ependymomas) were investigated using a single-voxel short-TE PRESS sequence on a 1.5 T scanner. Spectra were analysed using LCModel to yield metabolite profiles, and key metabolite assignments were verified by comparison with high-resolution magic-angle-spinning NMR of representative tumour biopsy samples. In addition to univariate metabolite comparisons, the use of multivariate classifiers was investigated. Principal component analysis was used for dimension reduction, and linear discriminant analysis was used for variable selection and classification. A bootstrap cross-validation method suitable for estimating the true performance of classifiers in small datasets was used. The discriminant function coefficients were stable and showed that medulloblastomas were characterised by high taurine, phosphocholine and glutamate and low glutamine, astrocytomas were distinguished by low creatine and high N-acetylaspartate, and ependymomas were differentiated by high myo-inositol and glycerophosphocholine. The same metabolite features were seen in NMR spectra of ex vivo samples. Successful classification was achieved for glial-cell (astrocytoma + ependymoma) versus non-glial-cell (medulloblastoma) tumours, with a bootstrap 0.632 + error, e(B.632+), of 5.3%. For astrocytoma vs medulloblastoma and astrocytoma vs medulloblastoma vs ependymoma classification, the e(B.632+) was 6.9% and 7.1%, respectively. The study showed that (1)H MRS detects key differences in the metabolite profiles for the main types of childhood cerebellar tumours and that discriminant analysis of metabolite profiles is a promising tool for classification. The findings warrant confirmation by larger multi-centre studies. PMID:18613254

Davies, N P; Wilson, M; Harris, L M; Natarajan, K; Lateef, S; Macpherson, L; Sgouros, S; Grundy, R G; Arvanitis, T N; Peet, A C

2008-10-01

270

Brain Tumor Classification Using AFM in Combination with Data Mining Techniques  

PubMed Central

Although classification of astrocytic tumors is standardized by the WHO grading system, which is mainly based on microscopy-derived, histomorphological features, there is great interobserver variability. The main causes are thought to be the complexity of morphological details varying from tumor to tumor and from patient to patient, variations in the technical histopathological procedures like staining protocols, and finally the individual experience of the diagnosing pathologist. Thus, to raise astrocytoma grading to a more objective standard, this paper proposes a methodology based on atomic force microscopy (AFM) derived images made from histopathological samples in combination with data mining techniques. By comparing AFM images with corresponding light microscopy images of the same area, the progressive formation of cavities due to cell necrosis was identified as a typical morphological marker for a computer-assisted analysis. Using genetic programming as a tool for feature analysis, a best model was created that achieved 94.74% classification accuracy in distinguishing grade II tumors from grade IV ones. While utilizing modern image analysis techniques, AFM may become an important tool in astrocytic tumor diagnosis. By this way patients suffering from grade II tumors are identified unambiguously, having a less risk for malignant transformation. They would benefit from early adjuvant therapies.

Huml, Marlene; Silye, Rene; Zauner, Gerald

2013-01-01

271

Brain tumor classification using AFM in combination with data mining techniques.  

PubMed

Although classification of astrocytic tumors is standardized by the WHO grading system, which is mainly based on microscopy-derived, histomorphological features, there is great interobserver variability. The main causes are thought to be the complexity of morphological details varying from tumor to tumor and from patient to patient, variations in the technical histopathological procedures like staining protocols, and finally the individual experience of the diagnosing pathologist. Thus, to raise astrocytoma grading to a more objective standard, this paper proposes a methodology based on atomic force microscopy (AFM) derived images made from histopathological samples in combination with data mining techniques. By comparing AFM images with corresponding light microscopy images of the same area, the progressive formation of cavities due to cell necrosis was identified as a typical morphological marker for a computer-assisted analysis. Using genetic programming as a tool for feature analysis, a best model was created that achieved 94.74% classification accuracy in distinguishing grade II tumors from grade IV ones. While utilizing modern image analysis techniques, AFM may become an important tool in astrocytic tumor diagnosis. By this way patients suffering from grade II tumors are identified unambiguously, having a less risk for malignant transformation. They would benefit from early adjuvant therapies. PMID:24062997

Huml, Marlene; Silye, René; Zauner, Gerald; Hutterer, Stephan; Schilcher, Kurt

2013-08-25

272

A parametric feature extraction and classification strategy for brain-computer interfacing  

Microsoft Academic Search

Parametric modeling strategies are explored in conjunction with linear discriminant analysis for use in an electroencephalogram (EEG)-based brain-computer interface (BCI). A left\\/right self-paced typing exercise is analyzed by extending the usual autoregressive (AR) model for EEG feature extraction with an AR with exogenous input (ARX) model for combined filtering and feature extraction. The ensemble averaged Bereitschaftspotential (an event related potential

Dave P. Burke; Simon P. Kelly; Philip de Chazal; Richard B. Reilly; Ciarán Finucane

2005-01-01

273

Classification of Brain Glioma by Using SVMs Bagging with Feature Selection  

Microsoft Academic Search

\\u000a The degree of malignancy in brain glioma needs to be assessed by MRI findings and clinical data before operations. There have\\u000a been previous attempts to solve this problem by using fuzzy max-min neural networks and support vector machines (SVMs), while\\u000a in this paper, a novel algorithm named PRIFEB is proposed by combining bagging of SVMs with embedded feature selection for

Guo-zheng Li; Tian-yu Liu; Victor S. Cheng

2006-01-01

274

O6-Methylguanine-DNA methyltransferase protein expression by immunohistochemistry in brain and non-brain systemic tumours: systematic review and meta-analysis of correlation with methylation-specific polymerase chain reaction  

PubMed Central

Background The DNA repair protein O6-Methylguanine-DNA methyltransferase (MGMT) confers resistance to alkylating agents. Several methods have been applied to its analysis, with methylation-specific polymerase chain reaction (MSP) the most commonly used for promoter methylation study, while immunohistochemistry (IHC) has become the most frequently used for the detection of MGMT protein expression. Agreement on the best and most reliable technique for evaluating MGMT status remains unsettled. The aim of this study was to perform a systematic review and meta-analysis of the correlation between IHC and MSP. Methods A computer-aided search of MEDLINE (1950-October 2009), EBSCO (1966-October 2009) and EMBASE (1974-October 2009) was performed for relevant publications. Studies meeting inclusion criteria were those comparing MGMT protein expression by IHC with MGMT promoter methylation by MSP in the same cohort of patients. Methodological quality was assessed by using the QUADAS and STARD instruments. Previously published guidelines were followed for meta-analysis performance. Results Of 254 studies identified as eligible for full-text review, 52 (20.5%) met the inclusion criteria. The review showed that results of MGMT protein expression by IHC are not in close agreement with those obtained with MSP. Moreover, type of tumour (primary brain tumour vs others) was an independent covariate of accuracy estimates in the meta-regression analysis beyond the cut-off value. Conclusions Protein expression assessed by IHC alone fails to reflect the promoter methylation status of MGMT. Thus, in attempts at clinical diagnosis the two methods seem to select different groups of patients and should not be used interchangeably.

2011-01-01

275

A discriminative model-constrained EM approach to 3D MRI brain tissue classification and intensity non-uniformity correction.  

PubMed

We describe a fully automated method for tissue classification, which is the segmentation into cerebral gray matter (GM), cerebral white matter (WM), and cerebral spinal fluid (CSF), and intensity non-uniformity (INU) correction in brain magnetic resonance imaging (MRI) volumes. It combines supervised MRI modality-specific discriminative modeling and unsupervised statistical expectation maximization (EM) segmentation into an integrated Bayesian framework. While both the parametric observation models and the non-parametrically modeled INUs are estimated via EM during segmentation itself, a Markov random field (MRF) prior model regularizes segmentation and parameter estimation. Firstly, the regularization takes into account knowledge about spatial and appearance-related homogeneity of segments in terms of pairwise clique potentials of adjacent voxels. Secondly and more importantly, patient-specific knowledge about the global spatial distribution of brain tissue is incorporated into the segmentation process via unary clique potentials. They are based on a strong discriminative model provided by a probabilistic boosting tree (PBT) for classifying image voxels. It relies on the surrounding context and alignment-based features derived from a probabilistic anatomical atlas. The context considered is encoded by 3D Haar-like features of reduced INU sensitivity. Alignment is carried out fully automatically by means of an affine registration algorithm minimizing cross-correlation. Both types of features do not immediately use the observed intensities provided by the MRI modality but instead rely on specifically transformed features, which are less sensitive to MRI artifacts. Detailed quantitative evaluations on standard phantom scans and standard real-world data show the accuracy and robustness of the proposed method. They also demonstrate relative superiority in comparison to other state-of-the-art approaches to this kind of computational task: our method achieves average Dice coefficients of 0.93 ± 0.03 (WM) and 0.90 ± 0.05 (GM) on simulated mono-spectral and 0.94 ± 0.02 (WM) and 0.92 ± 0.04 (GM) on simulated multi-spectral data from the BrainWeb repository. The scores are 0.81 ± 0.09 (WM) and 0.82 ± 0.06 (GM) and 0.87 ± 0.05 (WM) and 0.83 ± 0.12 (GM) for the two collections of real-world data sets-consisting of 20 and 18 volumes, respectively-provided by the Internet Brain Segmentation Repository. PMID:21558592

Wels, Michael; Zheng, Yefeng; Huber, Martin; Hornegger, Joachim; Comaniciu, Dorin

2011-05-10

276

The Pathogenesis of Tumour Associated Epilepsy  

Microsoft Academic Search

Summary  ??Tumour associated epilepsy (TAE) is a poorly understood manifestation of many gliomas, meningiomas and metastatic brain\\u000a tumours that has important clinical and social implications. Etiological mechanisms underlying tumour associated epilepsy\\u000a include theories invoking peritumoural amino acid disturbances, local metabolic imbalances, cerebral oedema, pH abnormalities,\\u000a morphological changes in the neuropil, changes in neuronal and glial enzyme and protein expression and altered

A. Beaumont; I. R. Whittle

2000-01-01

277

The classification of microglial activation phenotypes on neurodegeneration and regeneration in Alzheimer's disease brain.  

PubMed

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive decline of cognitive function. There is no therapy that can halt or reverse its progression. Contemporary research suggests that age-dependent neuroinflammatory changes may play a significant role in the decreased neurogenesis and cognitive impairments in AD. The innate immune response is characterized by pro-inflammatory (M1) activation of macrophages and subsequent production of specific cytokines, chemokines, and reactive intermediates, followed by resolution and alternative activation for anti-inflammatory signaling (M2a) and wound healing (M2c). We propose that microglial activation phenotypes are analogous to those of macrophages and that their activation plays a significant role in regulating neurogenesis in the brain. Microglia undergo a switch from an M2- to an M1-skewed activation phenotype during aging. This review will assess the neuroimmunological studies that led to characterization of the different microglial activation states in AD mouse models. It will also discuss the roles of microglial activation on neurogenesis in AD and propose anti-inflammatory molecules as exciting therapeutic targets for research. Molecules such as interleukin-4 and CD200 have proven to be important anti-inflammatory mediators in the regulation of neuroinflammation in the brain, which will be discussed in detail for their therapeutic potential. PMID:22710659

Varnum, Megan M; Ikezu, Tsuneya

2012-06-19

278

EEG brain mapping and brain connectivity index for subtypes classification of attention deficit hyperactivity disorder children during the eye-opened period.  

PubMed

Attention deficit hyperactivity disorder (ADHD) is one of the most prevalent neurological disorders. It is classified by the DSM-IV into three subtypes, i.e. 1) predominately inattentive type, 2) predominately hyperactive-impulsive type, and (3) combined type. In order to make the treatment via the neurofeedback or the occupational therapy, quantitative evaluations as well as ADHD subtype classification are the important problems to be solved to enhance an alternative way to treat ADHD. Hence, in this paper, we systematically classify all of these three subtypes by the 19-channel EEG data. Three brain mapping (QEEG) techniques, i.e. absolute power of frequency bands, coherence, and phase lag, are employed to visualize each type of the ADHD. ADHD children with combined type have deficit in delta theta and alpha activity. For the inattentive type, there are excessive delta and theta absolute power in the frontal area as well as the excessive coherence in beta and high beta frequency bands. For the hyperactivity and impulsive type, the behavior is dominated by the slow wave. This information will give benefits to the psychiatrist, psychologist, neurofeedback therapist as well as the occupational therapist for quantitatively planning and analyzing the treatment. PMID:24111455

Rodrak, Supassorn; Wongsawat, Yodchanan

2013-07-01

279

Method for the display, analysis, classification, and correlation of electrical brain function potentials  

US Patent & Trademark Office Database

An actuarial method for statistically determining the probable truth or falsity of a statement concerning a human subject and whether responses or statements made by the subject precede either a knowing representation by the subject of a truth or a lie. The method enables the correlation of a video image of a human subject, including mannerisms of the human subject, a selected plurality of eclectroencephalographic signals gathered from a plurality of electrodes located at specific points on the head of the subject, and a simultaneous detection or display of the subject's responses from a single video monitor combined with a computer analysis of the electroencephalographs to determine the subject's knowledge regarding a fact, a personal experience, and/or the truth or falsity of a particular statement by using a set of regression equations which establish before-truth, before-lie, during-truth, and during-lie base actuarial profiles for correlation and comparative analysis via computer. A system provides remote audio communication between the human subject and an examiner, a computer for analyzing electroencephalographic responses of the subject and comparing same with the base acturial profiles is provided and connected for receiving and sending a video image of the subjects face onto a portion of a monitor while simultaneously processing, sending and displaying the plurality of brain electrical waves on a another portion of the monitor. The electrical signals from the subject's brain are acquired using a novel disposable elastic skull cap with 19 electrodes pre-inserted in the cap in pre-selected positions. The computer digitizes each electrical signal over a unit of time and compares digitized signals for different epochs of times with the signals generated from selected epochs serving as actuarial base line signals.

1996-10-15

280

Somatostatin, cortistatin and their receptors in tumours  

Microsoft Academic Search

Somatostatin (SS) and its synthetic analogs have a role in the treatment of neuroendocrine tumours both in terms of symptoms control and antiproliferative activities. These effects are mediated by five SS receptors, widely expressed in both human neuroendocrine and non-neuroendocrine tumours, which were demonstrated to be diagnostically and therapeutically valuable targets. Cortistatin (CST), a brain cortex peptide, partially homologous to

M. Volante; R. Rosas; E. Allìa; R. Granata; A. Baragli; G. Muccioli; M. Papotti

2008-01-01

281

Extracting Multiscale Pattern Information of fMRI Based Functional Brain Connectivity with Application on Classification of Autism Spectrum Disorders  

PubMed Central

We employed a multi-scale clustering methodology known as “data cloud geometry” to extract functional connectivity patterns derived from functional magnetic resonance imaging (fMRI) protocol. The method was applied to correlation matrices of 106 regions of interest (ROIs) in 29 individuals with autism spectrum disorders (ASD), and 29 individuals with typical development (TD) while they completed a cognitive control task. Connectivity clustering geometry was examined at both “fine” and “coarse” scales. At the coarse scale, the connectivity clustering geometry produced 10 valid clusters with a coherent relationship to neural anatomy. A supervised learning algorithm employed fine scale information about clustering motif configurations and prevalence, and coarse scale information about intra- and inter-regional connectivity; the algorithm correctly classified ASD and TD participants with sensitivity of and specificity of . Most of the predictive power of the logistic regression model resided at the level of the fine-scale clustering geometry, suggesting that cellular versus systems level disturbances are more prominent in individuals with ASD. This article provides validation for this multi-scale geometric approach to extracting brain functional connectivity pattern information and for its use in classification of ASD.

Wang, Hui; Chen, Chen; Fushing, Hsieh

2012-01-01

282

Comparing implementations of magnetic-resonance-guided fluorescence molecular tomography for diagnostic classification of brain tumors  

NASA Astrophysics Data System (ADS)

Fluorescence molecular tomography (FMT) systems coupled to conventional imaging modalities such as magnetic resonance imaging (MRI) and computed tomography provide unique opportunities to combine data sets and improve image quality and content. Yet, the ideal approach to combine these complementary data is still not obvious. This preclinical study compares several methods for incorporating MRI spatial prior information into FMT imaging algorithms in the context of in vivo tissue diagnosis. Populations of mice inoculated with brain tumors that expressed either high or low levels of epidermal growth factor receptor (EGFR) were imaged using an EGF-bound near-infrared dye and a spectrometer-based MRI-FMT scanner. All data were spectrally unmixed to extract the dye fluorescence from the tissue autofluorescence. Methods to combine the two data sets were compared using student's t-tests and receiver operating characteristic analysis. Bulk fluorescence measurements that made up the optical imaging data set were also considered in the comparison. While most techniques were able to distinguish EGFR(+) tumors from EGFR(-) tumors and control animals, with area-under-the-curve values=1, only a handful were able to distinguish EGFR(-) tumors from controls. Bulk fluorescence spectroscopy techniques performed as well as most imaging techniques, suggesting that complex imaging algorithms may be unnecessary to diagnose EGFR status in these tissue volumes.

Davis, Scott C.; Samkoe, Kimberley S.; O'Hara, Julia A.; Gibbs-Strauss, Summer L.; Paulsen, Keith D.; Pogue, Brian W.

2010-09-01

283

O -(2-[ 18 F]Fluoroethyl)- l -tyrosine and l -[methyl- 11 C]methionine uptake in brain tumours: initial results of a comparative study  

Microsoft Academic Search

.   \\u000a O-(2-[18F]Fluoroethyl)-l-tyrosine (FET) is a recently described amino acid analogue that has shown high accumulation in animal tumours. The aim of\\u000a this study was to compare the uptake of FET with that of l-[methyl-11C]methionine (MET) in patients with suspected primary or recurrent intracerebral tumours. Sixteen consecutive patients with\\u000a intracerebral lesions were studied on the same day by positron emission

Wolfgang A. Weber; Hans-Jürgen Wester; Anca L. Grosu; Michael Herz; Brigitte Dzewas; Horst-Jürgen Feldmann; Michael Molls; Gerhard Stöcklin; Markus Schwaiger

2000-01-01

284

Tumours of the upper alimentary tract  

PubMed Central

Tumours of the oropharynx of domestic animals are common in most parts of the world, but squamous cell carcinoma of the upper alimentary tract shows differences in prevalence in different geographical areas and occurs at different sites in the various species. Oral tumours of the melanogenic system are more common in dogs than in man. The following main histological categories, which broadly correspond to those used in the classification of tumours of man, are described: papilloma; squamous cell carcinoma; salivary gland tumours; malignant melanoma; tumours of soft (mesenchymal) tissues; tumours of the facial bones; tumours of haematopoietic and related tissues; and odontogenic tumours and jaw cysts. Papilloma, squamous cell carcinoma, malignant melanoma, fibroma, and fibrosarcoma account for about 80% of the tumours that occur in the upper alimentary tract of domestic animals. ImagesFig. 6Fig. 7Fig. 8Fig. 9Fig. 34Fig. 35Fig. 36Fig. 37Fig. 2Fig. 3Fig. 4Fig. 5Fig. 22Fig. 23Fig. 24Fig. 25Fig. 26Fig. 27Fig. 28Fig. 29Fig. 14Fig. 15Fig. 16Fig. 17Fig. 30Fig. 31Fig. 32Fig. 33Fig. 18Fig. 19Fig. 20Fig. 21Fig. 10Fig. 11Fig. 12Fig. 13Fig. 1

Head, K. W.

1976-01-01

285

Urogenital tumours in childhood  

PubMed Central

Abstract The commonest urogenital tumours in childhood are Wilms tumour of the kidney and rhabdomyosarcoma in the pelvis. We review these tumours along with other primary renal tumours and less common ovarian and testicular tumours in childhood. Current clinical concepts, relevant staging investigations and imaging features are described.

Swinson, S.

2011-01-01

286

Carcinoid tumours.  

PubMed Central

The use of long-acting and potent somatostatin analogues is a major advance in the management of carcinoid tumours. In addition to providing effective symptom relief in malignant carcinoid syndrome, octreotide can also be used for diagnostic purposes. Despite its expense, octreotide is the current agent of choice for the treatment of this condition while analogues with different receptor specificities and pharmacokinetics hold promise for the future. Gastric carcinoids have aroused interest because of their experimental association with chronic hypergastrinaemia, a condition now commonplace because of the widespread use of H2-blockers and proton-pump inhibitors. This subject is reviewed. The slow evolution of many tumours demands prolonged follow-up and the active use of a variety of palliative interventions. These include measures such as hepatic and cardiac surgery, which might be deemed inappropriate for patients with other types of metastatic malignancy. Interferons may have a role when first-line treatments have failed. Chemotherapy is, generally, of limited value. Images Figure 1 Figure 2

Janmohamed, S.; Bloom, S. R.

1997-01-01

287

Prediction of central nervous system embryonal tumour outcome based on gene expression  

Microsoft Academic Search

Embryonal tumours of the central nervous system (CNS) represent a heterogeneous group of tumours about which little is known biologically, and whose diagnosis, on the basis of morphologic appearance alone, is controversial. Medulloblastomas, for example, are the most common malignant brain tumour of childhood, but their pathogenesis is unknown, their relationship to other embryonal CNS tumours is debated, and patients'

Scott L. Pomeroy; Pablo Tamayo; Michelle Gaasenbeek; Lisa M. Sturla; Michael Angelo; Margaret E. McLaughlin; John Y. H. Kim; Liliana C. Goumnerova; Peter M. Black; Ching Lau; Jeffrey C. Allen; David Zagzag; James M. Olson; Tom Curran; Cynthia Wetmore; Jaclyn A. Biegel; Tomaso Poggio; Shayan Mukherjee; Ryan Rifkin; Andrea Califano; Gustavo Stolovitzky; David N. Louis; Jill P. Mesirov; Eric S. Lander; Todd R. Golub

2002-01-01

288

Feature Extraction and Classification of EEG Signals Using Wavelet Transform, SVM and Artificial Neural Networks for Brain Computer Interfaces  

Microsoft Academic Search

Brain Computer Interface one of hopeful interface technologies between humans and machines. Electroencephalogram-based Brain Computer Interfaces have become a hot spot in the research of neural engineering, rehabilitation, and brain science. The artifacts are disturbance that can occur during the signal acquisition and that can alter the analysis of the signals themselves. Detecting artifacts produced in electroencephalography data by muscle

Mohammad Reza Nazari Kousarrizi; AbdolReza Asadi Ghanbari; Mohammad Teshnehlab; Mahdi Aliyari Shoorehdeli; Ali Gharaviri

2009-01-01

289

Radiotherapy by particle beams (hadrontherapy) of intracranial tumours: a survey on pathology  

Microsoft Academic Search

A review of the principal contributions of radiotherapy of brain tumours by beam particles is carried out. Neutrons, protons and light ions are considered along with their pros and cons in relation to types and locations of brain tumours. A particular emphasis is given to the pathologic studies of their effects directly on tumours and on the normal nervous tissue,

2005-01-01

290

Incidence and survival of childhood CNS tumours in the Region of Lombardy, Italy  

Microsoft Academic Search

Summary Incidence rates for CNS tumours in children of age 0-14 years in the Region of Lombardy, Italy, during the period 1988-93 were analysed; survival probability updated to December 1995 was also estimated. CNS tumours defined according to the International Classification of Diseases for Oncology codes were actively searched for. CNS tumours were diagnosed in 296 children. The age- standardized

Mariangela Farinotti; Massimo Ferrarini; Alessandra Solari; Graziella Filippini

1998-01-01

291

Motor Imaginary Signal Classification Using Adaptive Recursive Bandpass Filter and Adaptive Autoregressive Models for Brain Machine Interface Designs  

Microsoft Academic Search

The noteworthy point in the advancement of Brain Machine Interface (BMI) research is the ability to accurately extract features of the brain signals and to classify them into targeted control action with the easiest procedures since the expected beneficiaries are of disabled. In this paper, a new feature extraction method using the combination of adaptive band pass filters and adaptive

Vickneswaran Jeyabalan; Andrews Samraj; Loo Chu

2008-01-01

292

Elucidating a Magnetic Resonance Imaging-Based Neuroanatomic Biomarker for Psychosis: Classification Analysis Using Probabilistic Brain Atlas and Machine Learning Algorithms  

PubMed Central

Background No objective diagnostic biomarkers or laboratory tests have yet been developed for psychotic illness. Magnetic resonance imaging (MRI) studies consistently find significant abnormalities in multiple brain structures in psychotic patients relative to healthy control subjects, but these abnormalities show substantial overlap with anatomic variation that is in the normal range and therefore nondiagnostic. Recently, efforts have been made to discriminate psychotic patients from healthy individuals using machine-learning-based pattern classification methods on MRI data. Methods Three-dimensional cortical gray matter density (GMD) maps were generated for 36 patients with recent-onset psychosis and 36 sex- and age-matched control subjects using a cortical pattern matching method. Between-group differences in GMD were evaluated. Second, the sparse multinomial logistic regression classifier included in the Multivariate Pattern Analysis in Python machine-learning package was applied to the cortical GMD maps to discriminate psychotic patients from control subjects. Results Patients showed significantly lower GMD, particularly in prefrontal, cingulate, and lateral temporal brain regions. Pattern classification analysis achieved 86.1% accuracy in discriminating patients from controls using leave-one-out cross-validation. Conclusions These results suggest that even at the early stage of illness, psychotic patients present distinct patterns of regional cortical gray matter changes that can be discriminated from the normal pattern. These findings indicate that we can detect complex patterns of brain abnormality in early stages of psychotic illness, which has critical implications for early identification and intervention in individuals at ultra-high risk for developing psychosis/schizophrenia.

Sun, Daqiang; van Erp, Theo G.M.; Thompson, Paul M.; Bearden, Carrie E.; Daley, Melita; Kushan, Leila; Hardt, Molly E.; Nuechterlein, Keith H.; Toga, Arthur W.; Cannon, Tyrone D.

2011-01-01

293

[Genetics of neuroendocrine tumours, hereditary tumour syndromes].  

PubMed

Neuroendocrine tumours occur in some hereditary tumour syndromes, and the molecular pathophysiological mechanisms involved in these are also important in their sporadic counterparts which representing the majority of neuroendocrine tumours. These syndromes include multiple endocrine neoplasia type 1, von Hippel-Lindau syndrome, neurofibromatosis type 1 and tuberous sclerosis. All these follow an autosomal dominant inheritance. The primarily affected molecular pathways are Ras-MAPK signalling, hypoxia induced factor 1?, and mTOR signalling that are also involved in sporadic tumours and may even represent potential molecular targets of therapy. In this review, the major characteristics of hereditary tumour syndromes, their molecular genetics and the pathophysiological mechanisms involved in sporadic tumours are discussed. Orv. Hetil., 2013, 154, 1541-1548. PMID:24058099

Igaz, Péter

2013-09-01

294

The tumour-associated carbonic anhydrases CA II, CA IX and CA XII in a group of medulloblastomas and supratentorial primitive neuroectodermal tumours: an association of CA IX with poor prognosis  

Microsoft Academic Search

BACKGROUND: Medulloblastomas (MBs) and supratentorial primitive neuroectodermal tumours (PNETs) are the most common highly aggressive paediatric brain tumours. In spite of extensive research on these tumours, there are only few known biomarkers or therapeutic target proteins, and the prognosis of patients with these tumours remains poor. Our aim was to investigate whether carbonic anhydrases (CAs), enzymes commonly overexpressed in various

Kristiina Nordfors; Joonas Haapasalo; Miikka Korja; Anssi Niemelä; Jukka Laine; Anna-Kaisa Parkkila; Silvia Pastorekova; Jaromir Pastorek; Abdul Waheed; William S Sly; Seppo Parkkila; Hannu Haapasalo

2010-01-01

295

Brain Metastases From Breast Carcinoma: Validation of the Radiation Therapy Oncology Group Recursive Partitioning Analysis Classification and Proposition of a New Prognostic Score  

SciTech Connect

Purpose: To validate the Radiation Therapy Oncology Group Recursive Partitioning Analysis (RTOG RPA) classification and determine independent prognostic factors, to create a simple and specific prognostic score for patients with brain metastases (BM) from breast carcinoma treated with whole-brain radiotherapy (WBRT). Methods and Materials: From January 1998 through December 2003, 132 patients with BM from breast carcinoma were treated with WBRT. We analyzed several potential predictors of survival after WBRT: age, Karnofsky performance status, RTOG-RPA class, number of BM, presence and site of other systemic metastases, interval between primary tumor and BM, tumor hormone receptor (HR) status, lymphocyte count, and HER-2 overexpression. Results: A total of 117 patients received exclusive WBRT and were analyzed. Median survival with BM was 5 months. One-year and 2-year survival rates were 27.6% (95% confidence interval [CI] 19.9-36.8%) and 12% (95% CI 6.5-21.2%), respectively. In multivariate analysis, RTOG RPA Class III, lymphopenia ({<=}0.7 x 10{sup 9}/L) and HR negative status were independent prognostic factors for poor survival. We constructed a three-factor prognostic scoring system that predicts 6-month and 1-year rates of overall survival in the range of 76.1-29.5% (p = 0.00033) and 60.9-15.9% (p = 0.0011), respectively, with median survival of 15 months, 5 months, or 3 months for patients with none, one, or more than one adverse prognostic factor(s), respectively. Conclusions: This study confirms the prognostic value of the RTOG RPA classification, lymphopenia, and tumor HR status, which can be used to form a prognostic score for patients with BM from breast carcinoma.

Le Scodan, Romuald [Department of Radiation Oncology, Centre Rene Huguenin, Saint Cloud (France)], E-mail: lescodan@crh1.org; Massard, Christophe [Department of Radiation Oncology, Centre Rene Huguenin, Saint Cloud (France); Mouret-Fourme, Emmanuelle [Department of Medical Statistics, Centre Rene Huguenin, Saint Cloud (France); Guinebretierre, Jean Marc [Department of Pathology, Centre Rene Huguenin, Saint Cloud (France); Cohen-Solal, Christine; De Lalande, Brigitte; Moisson, Patricia; Breton-Callu, Christelle; Gardner, Miriam [Department of Radiation Oncology, Centre Rene Huguenin, Saint Cloud (France); Goupil, Alain [Department of Medical Oncology, Centre Rene Huguenin, Saint Cloud (France); Renody, Nicole; Floiras, Jean Louis; Labib, Alain [Department of Radiation Oncology, Centre Rene Huguenin, Saint Cloud (France)

2007-11-01

296

Cardiac tumours in children  

Microsoft Academic Search

Cardiac tumours are benign or malignant neoplasms arising primarily in the inner lining, muscle layer, or the surrounding pericardium of the heart. They can be primary or metastatic. Primary cardiac tumours are rare in paediatric practice with a prevalence of 0.0017 to 0.28 in autopsy series. In contrast, the incidence of cardiac tumours during foetal life has been reported to

Orhan Uzun; Dirk G Wilson; Gordon M Vujanic; Jonathan M Parsons; Joseph V De Giovanni

2007-01-01

297

Speeding up classification of multi-channel brain-computer interfaces: common spatial patterns for slow cortical potentials  

Microsoft Academic Search

During the last years interest has been growing to find an effective communication channel which translates human intentions into control signals for a computer, the so called brain-computer interface (BCI). One main goal of research is to help patients with severe neuromuscular disabilities by substituting normal motor outputs. Various cortical processes were identified which are suitable for implementing such a

Guido Dornhege; Benjamin Blankertz; Gabriel Curio

2003-01-01

298

Molecular mechanisms of brain tumor edema  

Microsoft Academic Search

Despite their diverse histological types, most brain tumours cause brain oedema, which is a significant cause of patient morbidity and mortality. Brain tumour oedema occurs when plasma-like fluid enters the brain extracellular space through impaired capillary endothelial tight junctions in tumours. Under-expression of the tight junction proteins occludin, claudin-1 and claudin-5 are key molecular abnormalities responsible for the increased permeability

M. C. Papadopoulos; S. Saadoun; D. K. Binder; G. T. Manley; S. Krishna; A. S. Verkman

2004-01-01

299

Case of tumour rickets.  

PubMed Central

A 10-year-old boy, with widespread soft tissue tumours of bone, developed hypophosphataemic rickets due to impaired renal tubular reabsorption of phosphate. Biopsy of the largest tumour showed a nonosteogenic fibroma. We believe this boy is another example of 'tumour rickets', as other causes of rickets were excluded clinically and biochemically. Cases of rickets or osteomalacia associated with a tumour, have generally been reported to be cured by surgical removal of the tumour, implicating it as the cause of rickets or osteomalacia. Owing to the large number of tumours in this boy, surgical removal was not possible, and he required large doses of vitamin D, together with oral phosphate, before his rickets healed. It is suggested that the tumour produces a phosphaturic hormone. Images Fig. 1 Fig. 2 Fig. 4

Moncrieff, M W; Brenton, D P; Arthur, L J

1978-01-01

300

Colorectal gastrointestinal mesenchymal tumours. Report of a stromal case of the rectum (GIST) and a leiomyosarcoma of the transverse colon  

Microsoft Academic Search

Background Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract. They are positive to C-kit (CD 117), more common in the older males, and mostly in the stomach, less in the colon and rectum and oesophagus. Benign tumours are more common than the malignant ones. Classification of GISTs is based on morphology and immunochemistry. Methods

A. Michalopoulos; V. N. Papadopoulos; G. Basdanis; E. Haralabopoulos; A. Zatagias; S. Netta; S. Apostolidis; E. Fahantidis

2004-01-01

301

HSV1716 injection into the brain adjacent to tumour following surgical resection of high-grade glioma: safety data and long-term survival  

Microsoft Academic Search

Following standard treatment, the prognosis remains poor in patients with high-grade glioma and new therapies are urgently required. Herpes simplex virus 1716 (HSV1716) is an ICP34.5 null mutant that is selectively replication competent and shown to be safe and to replicate following injection into high-grade glioma. We demonstrate that following surgical resection, HSV1716 is safe when injected into the brain

S Harrow; V Papanastassiou; J Harland; R Mabbs; R Petty; M Fraser; D Hadley; J Patterson; S M Brown; R Rampling

2004-01-01

302

Circulating tumour cells: insights into tumour heterogeneity.  

PubMed

Tumour heterogeneity is a major barrier to cure breast cancer. It can exist between patients with different intrinsic subtypes of breast cancer or within an individual patient with breast cancer. In the latter case, heterogeneity has been observed between different metastatic sites, between metastatic sites and the original primary tumour, and even within a single tumour at either a metastatic or a primary site. Tumour heterogeneity is a function of two separate, although linked, processes. First, genetic instability is a hallmark of malignancy, and results in 'fixed' genetic changes that are almost certainly carried forward through progression of the cancer over time, with increasingly complex additional genetic changes in new metastases as they arise. The second type of heterogeneity is due to differential but 'plastic' expression of various genes important in the biology and response to various therapies. Together, these processes result in highly variable cancers with differential response, and resistance, to both targeted (e.g. endocrine or anti-human epithelial growth receptor type 2 (HER2) agents) and nontargeted therapies (e.g. chemotherapy). Ideally, tumour heterogeneity would be monitored over time, especially in relation to therapeutic strategies. However, biopsies of metastases require invasive and costly procedures, and biopsies of multiple metastases, or serially over time, are impractical. Circulating tumour cells (CTCs) represent a potential surrogate for tissue-based cancer and therefore might provide the opportunity to monitor serial changes in tumour biology. Recent advances have enabled accurate and reliable quantification and molecular characterization of CTCs with regard to a number of important biomarkers including oestrogen receptor alpha and HER2. Preliminary data have demonstrated that expression of these markers between CTCs in individual patients with metastatic breast cancer reflects the heterogeneity of the underlying tumours. Future studies are designed to determine the clinical utility of these novel technologies in either research or routine clinical settings. PMID:23844916

Hayes, D F; Paoletti, C

2013-08-01

303

Brain source localization: A new method based on MUltiple SIgnal Classification algorithm and spatial sparsity of the field signal for electroencephalogram measurements  

NASA Astrophysics Data System (ADS)

Brain activity can be recorded by means of EEG (Electroencephalogram) electrodes placed on the scalp of the patient. The EEG reflects the activity of groups of neurons located in the head, and the fundamental problem in neurophysiology is the identification of the sources responsible of brain activity, especially if a seizure occurs and in this case it is important to identify it. The studies conducted in order to formalize the relationship between the electromagnetic activity in the head and the recording of the generated external field allow to know pattern of brain activity. The inverse problem, that is given the sampling field at different electrodes the underlying asset must be determined, is more difficult because the problem may not have a unique solution, or the search for the solution is made difficult by a low spatial resolution which may not allow to distinguish between activities involving sources close to each other. Thus, sources of interest may be obscured or not detected and known method in source localization problem as MUSIC (MUltiple SIgnal Classification) could fail. Many advanced source localization techniques achieve a best resolution by exploiting sparsity: if the number of sources is small as a result, the neural power vs. location is sparse. In this work a solution based on the spatial sparsity of the field signal is presented and analyzed to improve MUSIC method. For this purpose, it is necessary to set a priori information of the sparsity in the signal. The problem is formulated and solved using a regularization method as Tikhonov, which calculates a solution that is the better compromise between two cost functions to minimize, one related to the fitting of the data, and another concerning the maintenance of the sparsity of the signal. At the first, the method is tested on simulated EEG signals obtained by the solution of the forward problem. Relatively to the model considered for the head and brain sources, the result obtained allows to have a significant improvement compared to the classical MUSIC method, with a small margin of uncertainty about the exact location of the sources. In fact, the constraints of the spatial sparsity on the signal field allow to concentrate power in the directions of active sources, and consequently it is possible to calculate the position of the sources within the considered volume conductor. Later, the method is tested on the real EEG data too. The result is in accordance with the clinical report even if improvements are necessary to have further accurate estimates of the positions of the sources.

Vergallo, P.; Lay-Ekuakille, A.

2013-08-01

304

Brain source localization: a new method based on MUltiple SIgnal Classification algorithm and spatial sparsity of the field signal for electroencephalogram measurements.  

PubMed

Brain activity can be recorded by means of EEG (Electroencephalogram) electrodes placed on the scalp of the patient. The EEG reflects the activity of groups of neurons located in the head, and the fundamental problem in neurophysiology is the identification of the sources responsible of brain activity, especially if a seizure occurs and in this case it is important to identify it. The studies conducted in order to formalize the relationship between the electromagnetic activity in the head and the recording of the generated external field allow to know pattern of brain activity. The inverse problem, that is given the sampling field at different electrodes the underlying asset must be determined, is more difficult because the problem may not have a unique solution, or the search for the solution is made difficult by a low spatial resolution which may not allow to distinguish between activities involving sources close to each other. Thus, sources of interest may be obscured or not detected and known method in source localization problem as MUSIC (MUltiple SIgnal Classification) could fail. Many advanced source localization techniques achieve a best resolution by exploiting sparsity: if the number of sources is small as a result, the neural power vs. location is sparse. In this work a solution based on the spatial sparsity of the field signal is presented and analyzed to improve MUSIC method. For this purpose, it is necessary to set a priori information of the sparsity in the signal. The problem is formulated and solved using a regularization method as Tikhonov, which calculates a solution that is the better compromise between two cost functions to minimize, one related to the fitting of the data, and another concerning the maintenance of the sparsity of the signal. At the first, the method is tested on simulated EEG signals obtained by the solution of the forward problem. Relatively to the model considered for the head and brain sources, the result obtained allows to have a significant improvement compared to the classical MUSIC method, with a small margin of uncertainty about the exact location of the sources. In fact, the constraints of the spatial sparsity on the signal field allow to concentrate power in the directions of active sources, and consequently it is possible to calculate the position of the sources within the considered volume conductor. Later, the method is tested on the real EEG data too. The result is in accordance with the clinical report even if improvements are necessary to have further accurate estimates of the positions of the sources. PMID:24007117

Vergallo, P; Lay-Ekuakille, A

2013-08-01

305

Somatostatin, cortistatin and their receptors in tumours.  

PubMed

Somatostatin (SS) and its synthetic analogs have a role in the treatment of neuroendocrine tumours both in terms of symptoms control and antiproliferative activities. These effects are mediated by five SS receptors, widely expressed in both human neuroendocrine and non-neuroendocrine tumours, which were demonstrated to be diagnostically and therapeutically valuable targets. Cortistatin (CST), a brain cortex peptide, partially homologous to SS and having similar functions is also expressed in peripheral tissues and tumours. CST binds all SS receptors, and, differently from SS, also the ghrelin receptor GHSR1a and the CST specific receptor MrgX2. The expression profile of CST is mostly restricted to neuroendocrine tumours (gastrointestinal, pancreas, lung, parathyroid, thyroid, adrenal). In these tumours, CST probably acts via the SS or ghrelin receptor, the MrgX2 receptor being absent. Thus, in comparison to SS analogs, CST synthetic analogs may represent additional diagnostic/therapeutic tools in those tumours expressing the receptors for SS, for ghrelin or for both peptides. PMID:18248880

Volante, M; Rosas, R; Allìa, E; Granata, R; Baragli, A; Muccioli, G; Papotti, M

2007-12-08

306

Paediatric brachytherapy. II. Brain implantation.  

PubMed

The case histories of four children with brain tumours, for whom stereotactic brachytherapy was indicated, are presented from the St Bartholomew's Hospital intracranial brachytherapy programme. The recent evolution of the computed-tomography-directed stereotactic technique is described and the uses of different radionuclides (198Au, 192Ir) are discussed. The future of brachytherapy for paediatric brain tumours is debated. PMID:2539219

Thomson, E S; Afshar, F; Plowman, P N

1989-03-01

307

Imaging of sacral tumours  

Microsoft Academic Search

All components of the sacrum (bone, cartilage, bone marrow, meninges, nerves, notochord remnants, etc.) can give rise to benign\\u000a or malignant tumours. Bone metastases and intraosseous sites of haematological malignancies, lymphoma and multiple myeloma\\u000a are the most frequent aetiologies, while primary bone tumours and meningeal or nerve tumours are less common. Some histological\\u000a types have a predilection for the sacrum,

S. Gerber; L. Ollivier; J. Leclère; D. Vanel; G. Missenard; H. Brisse; G. de Pinieux; S. Neuenschwander

2008-01-01

308

Acquired brain injury  

Microsoft Academic Search

Acquired brain injury in childhood is not uncommon and arises from trauma, metabolic conditions, CNS tumours and infection, toxins or as a result of treatment. Injury to the brain can occur any time from just after conception onwards. Age of injury is a critical variable in determining outcome, as is the mechanism of injury. When the brain is in a

Judith A Middleton

2005-01-01

309

Hypoxia: targeting the tumour.  

PubMed

Solid tumours contain regions of very low oxygen concentrations that are said to be hypoxic. Hypoxia is a natural phenotype of solid tumours resulting from an imperfect vascular network. There are a number of consequences associated with tumour hypoxia including: resistance to ionising radiation, resistance to chemotherapy and the magnification of mutated p53. In addition tissue hypoxia has been regarded as a key factor for tumour aggressiveness and metastasis by activation of signal transduction pathways and gene regulatory mechanisms. It is clear that hypoxia in solid tumours promotes a strong oncogenic phenotype and is a phenomenon that occurs in all solid tumours. As such this provides a significant target for drug discovery particularly for tumour-targeting agents. A range of chemical classes (N-oxides, quinones, nitro-aromatics) have been explored as bioreductive agents that target tumour hypoxia. The most advanced agent, tirapazamine, is in phase III clinical trials in combination with cis-platin. The aim of this review is to give a brief overview of the current molecules and strategies being explored for targeting tumour hypoxia. PMID:16842231

Boyle, Robert George; Travers, Stuart

2006-07-01

310

Carcinoid tumour secreting dopa.  

PubMed Central

A middle aged woman referred for an abdominal mass was found to have large amounts of dopa (3-4-dihydroxyphenylalanine) metabolites in her urine. At operation a tumour affecting almost the entire left lobe of the liver was removed. Histologically the tumour was a metastatic carcinoid. After operation the excretion of dopa metabolites fell substantially, confirming that the tumour was the source. Apparently, owing to an enzyme defect the tumour had been unable to decarboxylate dopa. These findings are further evidence of a neural origin for the endocrine system of the gut.

Sharma, B K; Smits, B J; Robinson, R; Burns, S; Trounson, E N

1984-01-01

311

The tumour suppressor L(3)mbt inhibits neuroepithelial proliferation and acts on insulator elements  

Microsoft Academic Search

In Drosophila, defects in asymmetric cell division often result in the formation of stem-cell-derived tumours. Here, we show that very similar terminal brain tumour phenotypes arise through a fundamentally different mechanism. We demonstrate that brain tumours in l(3)mbt mutants originate from overproliferation of neuroepithelial cells in the optic lobes caused by derepression of target genes in the Salvador–Warts–Hippo (SWH) pathway.

Constance Richter; Katarzyna Oktaba; Jonas Steinmann; Jürg Müller; Juergen A. Knoblich

2011-01-01

312

The perivascular niche regulates breast tumour dormancy.  

PubMed

In a significant fraction of breast cancer patients, distant metastases emerge after years or even decades of latency. How disseminated tumour cells (DTCs) are kept dormant, and what wakes them up, are fundamental problems in tumour biology. To address these questions, we used metastasis assays in mice and showed that dormant DTCs reside on microvasculature of lung, bone marrow and brain. We then engineered organotypic microvascular niches to determine whether endothelial cells directly influence breast cancer cell (BCC) growth. These models demonstrated that endothelial-derived thrombospondin-1 induces sustained BCC quiescence. This suppressive cue was lost in sprouting neovasculature; time-lapse analysis showed that sprouting vessels not only permit, but accelerate BCC outgrowth. We confirmed this surprising result in dormancy models and in zebrafish, and identified active TGF-?1 and periostin as tumour-promoting factors derived from endothelial tip cells. Our work reveals that stable microvasculature constitutes a dormant niche, whereas sprouting neovasculature sparks micrometastatic outgrowth. PMID:23728425

Ghajar, Cyrus M; Peinado, Héctor; Mori, Hidetoshi; Matei, Irina R; Evason, Kimberley J; Brazier, Hélène; Almeida, Dena; Koller, Antonius; Hajjar, Katherine A; Stainier, Didier Y R; Chen, Emily I; Lyden, David; Bissell, Mina J

2013-06-02

313

Warburg tumours and the mechanisms of mitochondrial tumour suppressor genes. Barking up the right tree?  

PubMed

The past decade has seen a revival of interest in the metabolic adaptations of tumours, named for their original discoverer, Otto Warburg. Warburg reported a high rate of glycolysis in tumours, and a concurrent defect in mitochondrial respiration. The rediscovery of Warburg's hypothesis coincided with the discovery of mitochondrial tumours suppressor genes that may conform to Warburg's hypothesis. Succinate dehydrogenase and fumarate hydratase are mitochondrial proteins of the TCA cycle and the respiratory chain and when mutated lead to tumours of the nervous system known as paragangliomas and pheochromocytomas, and in the case of fumarate hydratase, cutaneous and uterine leiomyomas and renal cell cancer. Recently a novel mitochondrial protein, SDHAF2 (SDH5), was also shown to be a paraganglioma-related tumour suppressor gene. Another mitochondrial and TCA cycle-related protein, isocitrate dehydrogenase 2 is, together with IDH1, frequently mutated in the brain tumour glioblastoma. There are currently many competing hypotheses on the role of these genes in tumourigenesis, but frequent themes are the stabilization of hypoxia inducible factor 1 and upregulation of genes involved in angiogenesis, glucose transport and glycolysis. Other postulated mechanisms include the inhibition of developmental apoptosis, altered gene expression due to histone deregulation and the acquisition of novel catalytic properties. Here we discuss these diverse hypotheses and highlight very recent findings on the possible effects of IDH gene mutations. PMID:20304625

Bayley, Jean-Pierre; Devilee, Peter

2010-03-19

314

Tumeurs et malformations vasculaires, classification anatomopathologique et imagerie  

Microsoft Academic Search

The understanding of vascular anomalies (vascular tumours and vascular malformations) was obscured, for a long time, by confusion and uncertainties in nosology and terminology. The International Society for the Study of Vascular Anomalies (ISSVA) recently adopted a classification scheme, clearly separating vascular tumours (hemangiomas of different types) which result from active cell proliferation, from vascular malformations, which are inborn defects

M. Wassef; R. Vanwijck; P. Clapuyt; L. Boon; G. Magalon

2006-01-01

315

Tumour angiogenesis and response to radiotherapy.  

PubMed

The important role of angiogenesis as a predictive factor of response to cytotoxic and radiation therapy has been recently raised. Poor tumour oxygenation is a well recognised feature related to radio-resistance. Since the vascular density is linked to the availability of oxygen and drugs to the tumoural stroma, poor density should be a potent marker of reduced blood perfusion and, therefore, hypoxia and low drug intratumoural concentration. On the other hand, high vascular density and angiogenic ability of cancer is not synonymous with high blood flow since the geometry of the vascular/epithelial component distribution, vascular collapse due to increased interstitial blood pressure, or non-functional vasculature due to an immature structure of the vessels may not allow the establishment of an adequate blood flow, which results in tissue hypoxia. Moreover, activation of angiogenic pathways confer a cancer cell proliferation/apoptosis advantage and trigger an angiogenic regeneration process during fractionated radiotherapy or between the courses of chemotherapy, resulting in rapid tumour re-growth and failure of radiotherapy due to reasons independent of hypoxia and blood flow. The present study reviews the literature on angiogenesis and radiotherapy and suggests a classification of tumours according to their angiogenic ability, which could become a useful tool for the identification of sub-groups of patients that could benefit from specific radiotherapy schedules or combination regimens with cytotoxic and anti-angiogenic compounds. PMID:11908683

Koukourakis, M I

316

Gastrointestinal stromal tumour.  

PubMed

Gastrointestinal stromal tumours (GISTs) are mesenchymal neoplasms that arise in the gastrointestinal tract, usually in the stomach or the small intestine and rarely elsewhere in the abdomen. They can occur at any age, the median age being 60-65 years, and typically cause bleeding, anaemia, and pain. GISTs have variable malignant potential, ranging from small lesions with a benign behaviour to fatal sarcomas. Most tumours stain positively for the mast/stem cell growth factor receptor KIT and anoctamin 1 and harbour a kinase-activating mutation in either KIT or PDGFRA. Tumours without such mutations could have alterations in genes of the succinate dehydrogenase complex or in BRAF, or rarely RAS family genes. About 60% of patients are cured by surgery. Adjuvant treatment with imatinib is recommended for patients with a substantial risk of recurrence, if the tumour has an imatinib-sensitive mutation. Tyrosine kinase inhibitors substantially improve survival in advanced disease, but secondary drug resistance is common. PMID:23623056

Joensuu, Heikki; Hohenberger, Peter; Corless, Christopher L

2013-04-24

317

Disrupting tumour blood vessels  

Microsoft Academic Search

Low-molecular-weight vascular-disrupting agents (VDAs) cause a pronounced shutdown in blood flow to solid tumours, resulting in extensive tumour-cell necrosis, while they leave the blood flow in normal tissues relatively intact. The largest group of VDAs is the tubulin-binding combretastatins, several of which are now being tested in clinical trials. DMXAA (5,6-dimethylxanthenone-4-acetic acid) — one of a structurally distinct group of

Chryso Kanthou; Bruce C. Baguley; Gillian M. Tozer

2005-01-01

318

Carotid body tumour. Exicsion with resection of carotid arteries.  

PubMed

A case of carotid body tumour is reported and the salient features of its histopathology have been described. Its excision with resection of the carotid arteries can be safely undertaken if the tumour is of long duration, the angiography shows marked displacement of the carotid arteries and if the blood pressure is maintained during surgery by regulating the blood transfusion and lowering the head end of the patient, thereby preventing fatal brain hypoxia. The fact that it is a potentially malignant and radioresistant tumour, makes its excision with or without ligation of the carotid arteries almost imperative. PMID:1255014

Gupta, S; Gupta, O P; Verma, D N; Rastogi, B L

1976-03-01

319

Case Report: Meningioma with Intra-tumoural Haemorrhage Secondary to Ruptured Distal Anterior Cerebral Artery Aneurysm  

PubMed Central

Background: Brain tumours that are associated with cerebral aneurysms are rare occurrences, whereas the coexistence of brain tumours and intra-tumoural aneurysms is even rarer. There have been 12 brain tumour cases that have been reported in the literature that describe an aneurysm within a brain tumour, with 4 of these tumours being meningiomas. Case description: A 34-year-old male patient presented with sudden-onset headache, and an inter-hemispheric meningioma with intra-tumoural bleeding was found due to a ruptured embedded anterior cerebral artery aneurysm. The aneurysm was diagnosed incidentally on the third cerebral angiogram, while the initial 2 angiograms were negative. The patient was treated with endovascular aneurysm embolisation that was followed by tumour resection. Conclusion: This paper is the first case report to describe the coexistence of a meningioma and an aneurysm, which presented with intra-tumoural haemorrhage that was negative on the initial cerebral angiogram. Unlike previous case reports, the aneurysm in this case was located with an anterior cerebral artery distribution.

Alnaami, Ibrahim

2013-01-01

320

Leaf Classification  

NSDL National Science Digital Library

The purpose of this resource is to develop a classification system for a set of objects and learn about hierarchical classification systems. Any set of objects, such as insects or rocks, may be used as well.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

321

Predicting tumour response.  

PubMed

Response prediction is an important emerging concept in oncologic imaging, with tailored, individualized treatment regimens increasingly becoming the standard of care. This review aims to define tumour response and illustrate the ways in which imaging techniques can demonstrate tumour biological characteristics that provide information on the likely benefit to be received by treatment. Two imaging approaches are described: identification of therapeutic targets and depiction of the treatment-resistant phenotype. The former approach is exemplified by the use of radionuclide imaging to confirm target expression before radionuclide therapy but with angiogenesis imaging and imaging correlates for genetic response predictors also demonstrating potential utility. Techniques to assess the treatment-resistant phenotype include demonstration of hypoperfusion with dynamic contrast-enhanced computed tomography and magnetic resonance imaging (MRI), depiction of necrosis with diffusion-weighted MRI, imaging of hypoxia and tumour adaption to hypoxia, and 99mTc-MIBI imaging of P-glycoprotein mediated drug resistance. To date, introduction of these techniques into clinical practice has often been constrained by inadequate cross-validation of predictive criteria and lack of verification against appropriate response end points such as survival. With further refinement, imaging predictors of response could play an important role in oncology, contributing to individualization of therapy based on the specific tumour phenotype. This ability to predict tumour response will have implications for improving efficacy of treatment, cost-effectiveness and omission of futile therapy. PMID:24061161

Kyle, Samuel D; Law, W Phillip; Miles, Kenneth A

2013-09-23

322

Vascular endothelial growth factor is a potential tumour angiogenesis factor in human gliomas in vivo  

NASA Astrophysics Data System (ADS)

CLINICAL and experimental studies suggest that angiogenesis is a prerequisite for solid tumour growth1,2. Several growth factors with mitogenic or chemotactic activity for endothelial cells in vitro have been described, but it is not known whether these mediate tumour vascularization in vivo3,4. Glioblastoma, the most common and most malignant brain tumour in humans, is distinguished from astrocytoma by the presence of necroses and vascular prolifer-ations5'6. Here we show that expression of an endothelial cell-specific mitogen, vascular endothelial growth factor (VEGF), is induced in astrocytoma cells but is dramatically upregulated in two apparently different subsets of glioblastoma cells. The high-affinity tyrosine kinase receptor for VEGF, flt, although not expressed in normal brain endothelium, is upregulated in tumour endothelial cells in vivo. These observations strongly support the concept that tumour angiogenesis is regulated by paracrine mechanisms and identify VEGF as a potential tumour angiogenesis factor in vivo.

Plate, Karl H.; Breier, Georg; Weich, Herbert A.; Risau, Werner

1992-10-01

323

Bronchial carcinoid tumours  

PubMed Central

Some features of 22 cases of carcinoid tumour are described. The histology of the tumour was the criterion for inclusion in the series. The histology was reviewed by an observer unfamiliar with the clinical features. Six patients, each with an entirely endobronchial tumour of typical histology treated satisfactorily by surgery, are excluded from further consideration; the remaining 16 are considered for factors which may be significant in assessing the long-term prognosis, in addition to a histological assessment. The experience in this series is compared with a number of considerably larger series from the literature. The conclusion is reached that no single feature, histological or clinical, can be a basis for reaching a reliable prognosis. Lobectomy is regarded as the operation of choice in treatment. Images

Smith, R. Abbey

1969-01-01

324

Tumour related cutaneous elastophagocytosis.  

PubMed Central

Dermal granulomatous inflammation was identified immediately adjacent to seven (77%) of nine atypical fibroxanthomas arising in sun damaged skin. Concomitant elastophagocytosis was observed in five (56%) of these seven patients. Similar inflammation with elastophagocytosis was found in association with only two (6%) of 36 epithelial tumours arising on the same background (10 basal and 10 squamous cell carcinomas, 10 nodular malignant melanomas, and six keratocanthomas). Granulomatous inflammation is an unusual dermal reaction to tumour and elastophagocytosis is rare. The fact that both of these features occur with inordinate frequency in association with atypical fibroxanthomas, when compared with other, more common skin tumours, suggests that atypical fibroxanthomas might modulate the inflammatory response, either passively, by its dermal location, or actively, by secreting locally effective cytokines. Images

Sweeney, E C; McDermott, M

1996-01-01

325

Neonatal soft tissue tumours.  

PubMed Central

Thirty-five different soft tissue tumours occurring in the first month of life are described and classified into five Clinical Groups. A. Excellent prognosis with no treatment or simple surgical excision. B. Good prognosis. Treatment depends upon anatomical site. C. Good prognosis. Treatment usually surgical but chemotherapy may be indicated in certain situations. D. Intermediate prognosis. Treatment as for older child, usually surgery or chemotherapy. E. Poor prognosis. Treatment palliative or experimental. The relatively good prognosis of tumours in this age group and the importance of avoiding over-treatment are emphasised. Treatment guidelines are given and the value of obtaining tissue for biological studies to improve our understanding of these rare tumours is stressed. Images Figure 2 Figure 3 Figure 1 Figure 4

Spicer, R. D.

1992-01-01

326

An Epicurean learning approach to gene-expression data classification  

Microsoft Academic Search

We investigate the use of perceptrons for classification of microarray data where we use two datasets that were published in [Nat. Med. 7 (6) (2001) 673] and [Science 286 (1999) 531]. The classification problem studied by Khan et al. is related to the diagnosis of small round blue cell tumours (SRBCT) of childhood which are difficult to classify both clinically

Andreas Alexander Albrecht; Staal A. Vinterbo; Lucila Ohno-machado

2003-01-01

327

Tumour-educated macrophages promote tumour progression and metastasis  

Microsoft Academic Search

Evidence from clinical and experimental studies indicates that macrophages promote solid-tumour progression and metastasis. Macrophages are educated by the tumour microenvironment, so that they adopt a trophic role that facilitates angiogenesis, matrix breakdown and tumour-cell motility — all of which are elements of the metastatic process. During an inflammatory response, macrophages also produce many compounds — ranging from mutagenic oxygen

Jeffrey W. Pollard

2004-01-01

328

Survival of patients with nonseminomatous germ cell cancer: a review of the IGCC classification by Cox regression and recursive partitioning  

Microsoft Academic Search

The International Germ Cell Consensus (IGCC) classification identifies good, intermediate and poor prognosis groups among patients with metastatic nonseminomatous germ cell tumours (NSGCT). It uses the risk factors primary site, presence of nonpulmonary visceral metastases and tumour markers alpha-fetoprotein (AFP), human chorionic gonadotrophin (HCG) and lactic dehydrogenase (LDH). The IGCC classification is easy to use and remember, but lacks flexibility.

M R van Dijk; E W Steyerberg; S P Stenning; E Dusseldorp; J D F Habbema; van Dijk

2004-01-01

329

Aligning brains and minds  

PubMed Central

In this issue of Neuron, Haxby and colleagues describe a new method for aligning functional brain activity patterns across participants. Their study demonstrates that objects are similarly represented across different brains, allowing for reliable classification of one person’s brain activity based on another’s.

Tong, Frank

2012-01-01

330

Management of testicular tumours  

Microsoft Academic Search

Testis cancer is rare, but it is the commonest cause of malignancy in young men.Painless scrotal masses must be investigated with ultrasound imaging and tumour marker assay before being treated urgently with radical inguinal orchidectomy. Disease localized to the scrotum is curable with surgery alone in most cases, but high-risk features in clinical stage 1 disease predict failure in a

Noel W. Clarke; Lynsey McHugh

2010-01-01

331

VEGFA and tumour angiogenesis.  

PubMed

In this review we summarize the current understanding of signal transduction downstream of vascular endothelial growth factor A (VEGFA) and its receptor VEGFR2, and the relationship between these signal transduction pathways and the hallmark responses of VEGFA, angiogenesis and vascular permeability. These physiological responses involve a number of effectors, including extracellular signal-regulated kinases (ERKs), Src, phosphoinositide 3 kinase (PI3K)/Akt, focal adhesion kinase (FAK), Rho family GTPases, endothelial NO and p38 mitogen-activated protein kinase (MAPK). Several of these factors are involved in the regulation of both angiogenesis and vascular permeability. Tumour angiogenesis primarily relies on VEGFA-driven responses, which to a large extent result in a dysfunctional vasculature. The reason for this remains unclear, although it appears that certain aspects of the VEGFA-stimulated angiogenic milieu (high level of microvascular density and permeability) promote tumour expansion. The high degree of redundancy and complexity of VEGFA-driven tumour angiogenesis may explain why tumours commonly develop resistance to anti-angiogenic therapy targeting VEGFA signal transduction. PMID:23216836

Claesson-Welsh, L; Welsh, M

2013-02-01

332

Gating and tracking, 4D in thoracic tumours.  

PubMed

The limited ability to control for a tumour's location compromises the accuracy with which radiation can be delivered to tumour-bearing tissue. The resultant requirement for larger treatment volumes to accommodate target uncertainty restricts the radiation dose because more surrounding normal tissue is exposed. With image-guided radiation therapy (IGRT), these volumes can be optimized and tumouricidal doses may be delivered, achieving maximum tumour control with minimal complications. Moreover, with the ability of high precision dose delivery and real-time knowledge of the target volume location, IGRT has initiated the exploration of new indications in radiotherapy such as hypofractionated radiotherapy (or stereotactic body radiotherapy), deliberate inhomogeneous dose distributions coping with tumour heterogeneity (dose painting by numbers and biologically conformal radiation therapy), and adaptive radiotherapy. In short: "individualized radiotherapy". Tumour motion management, especially for thoracic tumours, is a particular problem in this context both for the delineation of tumours and organs at risk as well as during the actual treatment delivery. The latter will be covered in this paper with some examples based on the experience of the UZ Brussel. With the introduction of the NOVALIS system (BrainLAB, Feldkirchen, Germany) in 2000 and consecutive prototypes of the ExacTrac IGRT system, gradually a hypofractionation treatment protocol was introduced for the treatment of lung tumours and liver metastases evolving from motion-encompassing techniques towards respiratory-gated radiation therapy with audio-visual feedback and most recently dynamic tracking using the VERO system (BrainLAB, Feldkirchen, Germany). This evolution will be used to illustrate the recent developments in this particular field of research. PMID:20673737

Verellen, D; Depuydt, T; Gevaert, T; Linthout, N; Tournel, K; Duchateau, M; Reynders, T; Storme, G; De Ridder, M

2010-07-31

333

Fatty tumours of the uterus.  

PubMed Central

Uterine fatty tumours (UFT) are uncommon and have received little attention in the English literature. They have aroused interest as a consequence of occasional diagnostic confusion with sarcomas and the continuing unresolved dispute as to their histogenesis. Three cases of UFT are described and the pathological features of note discussed. The viewpoint that these tumours are hamartomas/choristomas is rejected. UFT most probably represent tumour metaplasia within a leiomyoma. There is no uniform accepted nomenclature for such tumours and it is suggested that they be designated "uterine fatty tumours" and subdivided into "lipoma" and "mixed lipoma/leiomyoma" (synonym lipoleiomyoma). Images

Pounder, D J

1982-01-01

334

Malignant tumours of the jaws.  

PubMed

Almost all variants of malignant primary and secondary tumours of bone have been described as occurring within the jaws. Odontogenic carcinomas and sarcomas are peculiar to the jawbones and are distinctly uncommon. Non-odontogenic tumours in comparison arise with more frequency, yet the maxilla and mandible remain unusual sites for most primary and secondary non-odontogenic tumours of bone. The most commonly occurring primary bone tumours affecting the jaws include osteosarcoma, Burkitt's lymphoma and multiple myeloma, while secondary or metastatic tumours to the jaws are rare in contrast to the remainder of the skeleton. PMID:23957100

Coleman, H; Sukumar, S

2012-11-01

335

Management of extracolonic tumours in patients with Lynch syndrome  

Microsoft Academic Search

Hereditary nonpolyposis colorectal cancer, or Lynch syndrome, is responsible for 2-3% of all colorectal cancers. Lynch syndrome is also associated with a high risk of extracolonic cancers, including endometrial, stomach, small bowel, pancreas, biliary tract, ovary, urinary tract, brain, and skin cancer. In this Review, we discuss the risks, surveillance tests, and guidelines for the management of extracolonic tumours associated

Jan J Koornstra; Marian JE Mourits; Rolf H Sijmons; Annemarie M Leliveld; Harry Hollema; Jan H Kleibeuker

2009-01-01

336

Fingerprint classification  

Microsoft Academic Search

A fingerprint classification algorithm is presented in this paper. Fingerprints are classified into five categories: arch, tented arch, left loop, right loop and whorl. The algorithm extracts singular points (cores and deltas) in a fingerprint image and performs classification based on the number and locations of the detected singular points. The classifier is invariant to rotation, translation and small amounts

Kalle Karu; Anil K. Jain

1996-01-01

337

Tumours of the spleen.  

PubMed

The spleen has been considered a 'forgotten organ' even if it is included and well demonstrated on every CT and MRI of the abdomen. Tumours of the spleen are rare; however, radiologists need to be aware of the main tumoral features and patterns in order to try to distinguish between benign and malignant masses often discovered incidentally. The principal tumoral masses, benign (cysts, haemangiomas, litteral cell angioma, lymphangioma) and malignant (lymphoma, metastases haemangiosarcoma), are described. PMID:16154823

Giovagnoni, Andrea; Giorgi, Chiara; Goteri, Gaia

2005-07-25

338

Thymic tumours: An update.  

PubMed

Thymic malignancies are relatively uncommon tumours that display significant clinical, pathological, and molecular heterogeneity. Their management requires a multidisciplinary approach; because of their rarity, current indications are based on data from smaller, mostly institutional, series or retrospective analyses and controversies still exist. This article focuses on the principles of treatment of thymic malignancies. In the future, collaboration between many different institutions will open the opportunity to achieve a better understanding and management of the disease. PMID:23998928

Polo, Valentina; Girard, Nicolas; Besse, Benjamin

2013-08-30

339

Epidemiology of Neuroendocrine Tumours  

Microsoft Academic Search

Neuroendocrine tumours account for only 0.5% of all malignancies. The incidence is approximately 2\\/100,000 with a female preponderance under the age of 50 years due to appendiceal location. The main primary sites are the gastrointestinal tract (62–67%) and the lung (22–27%). Presentation with metastatic disease accounts for 12–22%. In the last decades, the incidence has been rising. This might be

B. G. Taal; O. Visser

2004-01-01

340

Borderline ovarian tumours.  

PubMed

Borderline ovarian tumours account for 10-20% of all epithelial ovarian cancer. Historically, standard primary surgery has included borderline ovarian tumours, omentectomy, peritoneal washing and multiple biopsies. As one-third of borderline ovarian tumours are diagnosed in women under the age of 40 years, fertility-sparing treatment has been more frequently used in the past 10 years. Fertility drugs are well tolerated in women with infertility after fertility-sparing surgery. Careful selection of candidates is necessary. Laparoscopic techniques can be used, but should be reserved for oncologic surgeons. This conservative treatment increases the rate of recurrence, albeit with no effect on survival. The pregnancy rate is nearly 50%, and most are achieved spontaneously. These women should be closely followed up. The question is whether this is acceptable from a gynaecologic oncologic point of view. For this reason, we will discuss recently published studies and gynaecologic oncologic concerns about the mode of fertility-sparing surgery and its consequences. PMID:22321906

Tropé, Claes Göran; Kaern, Janne; Davidson, Ben

2012-02-07

341

Clinical management of brain metastasis  

Microsoft Academic Search

Brain metastasis is a common complication ocurring in about 15–20% of all cancer patients. For the initial management, distinguishing\\u000a between three types of presentation is essential: de novo brain metastasis, simultaneous presentation of both brain metastasis\\u000a and the primary tumour (usually lung carcinoma), and the presentation of a patient known to have systemic cancer developing\\u000a a brain metastasis. For de

Ch. J. Vecht; Daniel den Hoed

1998-01-01

342

Graz brain-computer interface II: towards communication between humans and computers based on online classification of three different EEG patterns  

Microsoft Academic Search

The paper describes work on the brain-computer interface (BCI). The BCI is designed to help patients with severe motor impairment\\u000a (e.g. amyotropic lateral sclerosis) to communicate with their environment through wilful modification of their EEG. To establish\\u000a such a communication channel, two major prerequisites have to be fulfilled: features that reliably describe several distinctive\\u000a brain states have to be available,

J. Kalcher; D. Flotzinger; Ch. Neuper; S. Gölly; G. Pfurtscheller

1996-01-01

343

Molecular study of the tumour suppressor gene PTEN in gastric adenocarcinoma in Brazil  

Microsoft Academic Search

\\u000a Abstract\\u000a   Among all tumours diagnosed worldwide, gastric adenocarcinoma is the second most frequent type of malignancy. In Brazil, it\\u000a is estimated to be the fifth most frequent type of neoplasia. According to the classification of Laurén, these tumours are\\u000a divided into well differentiated and ill differentiated gastric adenocarcinomas. There are studies suggesting that the first\\u000a type develops through remodulation of

E. M. Lima; J. J. Araújo; M. L. Harada; P. P. Assumpção; R. R. Burbano; C. Casartelli

2005-01-01

344

[Surgical therapy for adrenal tumours].  

PubMed

Four endoscopic and four open accesses are available for the surgery of adrenal tumours. The decision to use one of the available techniques depends on tumour size, body mass index, previous abdominal surgery and the experience of the surgeon. Currently, the lateral laparoscopic and the dorsal retroperitoneoscopic approaches are most frequently used. Conventional surgery should be used if malignancy is suspected, especially for tumours larger than 6 cm. In individual cases, even tumours up to 10 cm can be operated laparoscopically if there is no suspicion of invasive growth or lymphatic metastases. Each surgeon should choose the most familiar access. The retroperitoneoscopic and laparoscopic accesses for benign adrenal tumours up to 6 cm are considered to be equivalent. The surgeon should also be able to approach adrenal tumours conventionally. PMID:20549586

Agha, A; Iesalnieks, I; Glockzin, G; Schlitt, H J

2010-06-14

345

Mineral Classification  

NSDL National Science Digital Library

This problem set challenges students to determine the chemical classification of minerals based on their chemical formula (provided). For oxygen-bearing minerals, students must also provide the valences of the various cations.

346

Brenner tumour of the vagina.  

PubMed Central

Polyps of the vagina are rare and are either of inflammatory/reactive or neoplastic origin. A case of extraovarian Brenner tumour of the vagina in a postmenopausal woman, who presented with a vaginal polyp, is described. The polyp was excised and on histological examination, had the triphasic pattern (transitional, glandular and stromal) characteristic of Brenner tumour. The histogenesis of Brenner tumour is discussed in the context of this unusual location and the controversy of its origin. Images

Rashid, A M; Fox, H

1995-01-01

347

Brenner tumour of the vagina.  

PubMed

Polyps of the vagina are rare and are either of inflammatory/reactive or neoplastic origin. A case of extraovarian Brenner tumour of the vagina in a postmenopausal woman, who presented with a vaginal polyp, is described. The polyp was excised and on histological examination, had the triphasic pattern (transitional, glandular and stromal) characteristic of Brenner tumour. The histogenesis of Brenner tumour is discussed in the context of this unusual location and the controversy of its origin. PMID:7560181

Rashid, A M; Fox, H

1995-07-01

348

A human tumour model.  

PubMed

An approach to the management of patients with large (greater than 4 cm) operable breast cancers is described. The conventional sequence of mastectomy followed by systemic therapy is reversed, allowing accurate measurements of response to individual forms of endocrine therapy or chemotherapy. Such a method not only permits individual selection of appropriate systemic therapy, but also allows clinical response to be related to histological and biochemical tumour parameters. A response was observed in eleven of twenty-three patients to endocrine treatment and in twelve of thirteen to combination chemotherapy. In five of the latter the response was histologically complete. PMID:2876282

Forrest, A P; Levack, P A; Chetty, U; Hawkins, R A; Miller, W R; Smyth, J F; Anderson, T J

1986-10-11

349

Tumour angiogenesis in latent prostatic carcinoma  

Microsoft Academic Search

Unrestrained growth of various malignant tumours has been shown to depend upon a critical number of tumour cells which have switched to the angiogenic phenotype. Angiogenic phenotypes were noted in the early stage of prostatic carcinoma (PCa). We investigated 65 cases of latent PCa to define the correlation between tumour angiogenesis and tumour volume. Tumour angiogenesis was determined by the

M Furusato; S Wakui; H Sasaki; K Ito; S Ushigome

1994-01-01

350

Tumour endothelial cells acquire drug resistance in a tumour microenvironment.  

PubMed

Tumour growth is dependent on angiogenesis, and tumour blood vessels are recognized as an important target for cancer therapy. Tumour endothelial cells (TECs) are the main targets of anti-angiogenic therapy. Unlike the traditionally held view, some TECs may be genetically abnormal and might acquire drug resistance. Therefore, we investigated the drug resistance of TECs and the mechanism by which it is acquired. TECs show resistance to paclitaxel through greater mRNA expression of multidrug resistance 1, which encodes P-glycoprotein, as compared with normal endothelial cells. We found that high levels of vascular endothelial growth factor in tumour-conditioned medium may be responsible for upregulated P-glycoprotein expression. This is a novel mechanism for the acquisition of drug resistance by TECs in a tumour microenvironment. This review focuses on the possibility that TECs can acquire drug resistance. PMID:23293323

Hida, Kyoko; Akiyama, Kosuke; Ohga, Noritaka; Maishi, Nako; Hida, Yasuhiro

2013-01-03

351

Equine sarcoid tumour treated by autogenous tumour vaccine.  

PubMed

Twenty-one horses with sarcoid tumours were treated by bio-immunotherapy using autogenous vaccines during 1991-1997. At operation the base of the tumour was left in the skin and autovaccines were made from extirpated tumour tissue by polymerization. The horses thus formed their own internal control group. One of 12 horses having a primary tumour, and four of 9 horses suffering recurrent tumours, prior to bio-immunotherapy, developed single recurrences. Four of these five horses suffering recurrence were treated anew, leading to remission. Disease-free intervals were longer for primary (P = 0.0005) and recurrent sarcoids (P = 0.0156) than for conventional surgery alone. Mitochondrial events seem to effect the healing. PMID:10629622

Kinnunen, R E; Tallberg, T; Stenbäck, H; Sarna, S

352

A brain–computer interface (BCI) for the locked-in: comparison of different EEG classifications for the thought translation device  

Microsoft Academic Search

Objective: The Thought Translation Device (TTD) for brain–computer interaction was developed to enable totally paralyzed patients to communicate. Patients learn to regulate slow cortical potentials (SCPs) voluntarily with feedback training to select letters. This study reports the comparison of different methods of electroencephalographic (EEG) analysis to improve spelling accuracy with the TTD on a data set of 6650 trials of

Thilo Hinterberger; Andrea Kübler; Jochen Kaiser; Nicola Neumann; Niels Birbaumer

2003-01-01

353

Terrain classification  

NASA Astrophysics Data System (ADS)

This work presents methods for terrain classification that support adaptive selection of parameters for Terrain Classification system. Work is also presented for water body detection and we present results from experiments conducted for water detection methods utilizing LADAR, color camera and polarization filter based sensors. Use of multiple sensors can provide better water detection capability. An approach for adaptive terrain classification is shown for existing rule-based classification algorithms. This approach allows us to develop a set of rules for various representative terrain types from various sites and operating conditions (light level, humidity, season, etc.) and exploit the onboard vehicle situational knowledge to select the most suitable set of rules for operation. An important element of this work requires use of data collected for different seasons and locations or terrain types in order to provide sensitivity measures. Existing terrain classification algorithms can utilize input from multiple sensors such as: Color, LADAR, FLIR and Multi-Spectral imagery. The performance of these algorithms is expected to improve as we acquire an increasing number of additional data sets that includes features of interest taken under various conditions of terrain-types types, illumination, temperature, humidity etc. and allow us to build a database of terrain knowledge. Environmental nformation and ground-truth is also collected along with the sensor data data. A Geographical Information System (GIS) interface is utilized along with related public-domain tools. Such tools are integrated to our system and used to provide data-management, spatial-modeling, and visualization.

Sarwal, Alok; Simon, David; Rajagopalan, Venkat

2003-09-01

354

Non-adenomatous pituitary tumours.  

PubMed

Apart from pituitary adenomas, a number of tumours may arise from within the sella presenting a diagnostic and therapeutic challenge at a multidisciplinary specialist level. This article focus on the most commonly diagnosed non-adenomatous pituitary tumours (craniopharyngiomas, Rathke's cleft cysts and meningiomas) and provides data on their pathogenesis, diagnosis and treatment. PMID:19945029

Karavitaki, Niki; Wass, John A H

2009-10-01

355

Integrin signalling during tumour progression  

Microsoft Academic Search

During progression from tumour growth to metastasis, specific integrin signals enable cancer cells to detach from neighbouring cells, re-orientate their polarity during migration, and survive and proliferate in foreign microenvironments. There is increasing evidence that certain integrins associate with receptor tyrosine kinases (RTKs) to activate signalling pathways that are necessary for tumour invasion and metastasis. The effect of these integrins

Wenjun Guo; Filippo G. Giancotti

2004-01-01

356

Tumour Banking: The Spanish Design  

Microsoft Academic Search

In the last decade the technical advances in high throughput techniques to analyze DNA, RNA and proteins have had a potential major impact on prevention, diagnosis, prognosis and treatment of many human diseases. Key pieces in this process, mainly thinking about the future, are tumour banks and tumour bank networks. To face these challenges, diverse suitable models and designs can

M. M. Morente; E. de Alava; P. L. Fernandez

2007-01-01

357

Accumulation of exogenous sensitizers in rat brain  

Microsoft Academic Search

Background. Nowadays fluorescence diagnostics can be applied for tumour boundary deline- ation. One of the most important sensitizer's characteristics in fluorescence diagnostics is ac- cumulation and distribution in biological tissue. However, the blood-brain barrier protects the brain, and, as a consequence, the accumulation of sensitizers in the brain should be restricted. Unfortunately, there are not enough comparative studies about the

Vytautas Kulvietis; Juozas Lapienis

358

Classification Fun  

NSDL National Science Digital Library

Taxonomic information shows the evolutionary relationships between organisms. In this lesson plan, students will classify organisms by kingdom and apply their own understanding of classification to identify organisms. The students should already have an understanding of the basics of the five kindoms and the seven categories of classification. The document includes a pre-test on the topic to gauge student understanding and two classroom activities. The activity is intended for sixth grade students, and should take three to four class periods to complete.

Shubinski, Carol

2012-06-11

359

The tumour suppressor L(3)mbt inhibits neuroepithelial proliferation and acts on insulator elements.  

PubMed

In Drosophila, defects in asymmetric cell division often result in the formation of stem-cell-derived tumours. Here, we show that very similar terminal brain tumour phenotypes arise through a fundamentally different mechanism. We demonstrate that brain tumours in l(3)mbt mutants originate from overproliferation of neuroepithelial cells in the optic lobes caused by derepression of target genes in the Salvador-Warts-Hippo (SWH) pathway. We use ChIP-sequencing to identify L(3)mbt binding sites and show that L(3)mbt binds to chromatin insulator elements. Mutating l(3)mbt or inhibiting expression of the insulator protein gene mod(mdg4) results in upregulation of SWH pathway reporters. As l(3)mbt tumours are rescued by mutations in bantam or yorkie or by overexpression of Expanded, the deregulation of SWH pathway target genes is an essential step in brain tumour formation. Therefore, very different primary defects result in the formation of brain tumours, which behave quite similarly in their advanced stages. PMID:21857667

Richter, Constance; Oktaba, Katarzyna; Steinmann, Jonas; Müller, Jürg; Knoblich, Juergen A

2011-08-21

360

'Tumour-induced osteomalacia'.  

PubMed

A 60-year-old man presented 2 years before his diagnosis with long-standing muscle cramping, progressive generalised weakness and chronic hip pain. The patient was found to have bilateral femoral neck pathologic fractures therefore, underwent reamed intramedullary nailing of both femurs. Laboratory studies showed hypophosphataemia. Bone marrow biopsy was negative for malignancy. Positron emission tomography demonstrated fludeoxyglucose uptake only in the posterior neck. Bone scan showed innumerable foci of increased activity throughout the skeleton consistent with pseudofractures seen in osteomalacia. Fine needle aspiration from the mass in the neck revealed a phosphaturic mesenchymal tumour of mixed connective tissue type. Resection of the mass in the neck resulted in resolution of generalised complaints with no evidence of recurrence with a follow-up of 12 months. PMID:22736784

Munoz, Javier; Michel Ortega, Rosa; Celzo, Florence; Donthireddy, Vijayalakshmi

2012-06-25

361

Role of stereotactic biopsy in multifocal brain lesions: considerations on 100 consecutive cases  

Microsoft Academic Search

One hundred patients affected by multifocal brain lesions were investigated by serial stereotactic biopsy. Systemic diseases and primary neoplasms elsewhere were previously ruled out. The histological diagnosis obtained in this series comprises malignant gliomas in 37% of patients; primary non-Hodgkin's brain lymphoma in 15%; metastatic brain tumours in 15% (no evidence of the primary tumour at the time of stereotactic

A Franzini; F Leocata; C Giorgi; A Allegranza; D Servello; G Broggi

1994-01-01

362

Histopathological Diagnostic Discrepancies in Soft Tissue Tumours Referred to a Specialist Centre  

PubMed Central

Aims. A study was performed to determine areas of diagnostic discrepancy in the reporting of cases of soft tissue tumours referred to a specialist sarcoma unit. This was to pinpoint common discrepancies and to determine their causes. Methods and Results. We compared the sarcoma unit's histopathology reports with referring reports on 349 specimens from 277 patients with suspected or proven soft tissue tumours in a one-year period. Conclusions. Diagnostic agreement was found in 256 of 349 cases (73.4%), with minor diagnostic discrepancy in 55 cases (15.7%) and major discrepancy in 38 cases (10.9%). Benign/malignant discordances accounted for only 5% of all discrepancies (5 cases). The most common discrepancies occurred in tumour classification, including diagnosis of gastrointestinal stromal tumour and leiomyosarcoma and the subtyping of spindle cell sarcomas, as well as in tumour grading that could conceivably lead to changes in clinical management. Major diagnostic discrepancies leading to management change occurred in a relatively select range of tumour groups, and almost all discrepancies occurred due to differences in tumour interpretation between general or nonsoft tissue pathologists, and pathologists at the specialist unit. The findings support guidelines by the National Institute for Health and Clinical Excellence that diagnostic review of soft tissue tumours should be performed by specialist soft tissue pathologists.

Thway, Khin; Fisher, Cyril

2009-01-01

363

Image Classification  

NSDL National Science Digital Library

In this exercise, students get experience with image classification. Images are an increasingly important source of information about land cover and land use over time because comparisons of historic and current images can provide an estimate of change in the landscape.

Cote, Paul; Welch, Brian C.

2008-10-14

364

[Medical treatment of neuroendocrine tumours].  

PubMed

The author aims to review the established medical treatment options of neuroendocrine tumours, which have expanded greatly in recent years and present the most important aspects to be considered in planning patients' management. Medical treatment is usually considered in advanced stages of these tumours, as well as in cases of hormone overproduction. Somatostatin analogues have been known to be effective in alleviating hormone excess syndromes, especially carcinoid syndrome for the past 25 years. There is a convincing evidence that the somatostatin analogue octreotide is useful as an antitumor agent, at least in well-differentiated small intestinal neuroendocrine tumours and probably also in those of pancreatic origin. Interferons may be also used and the indications for their use may be almost the same. Optimal patient selection is mandatory for the use of cytotoxic chemotherapy. Streptozotocin- and, recently, temozolomide-based chemotherapies should be considered in progressive phases of well differentiated (G1/G2) pancreatic neuroendocrine tumours. A cisplatin-etoposide combination is the first choice for the treatment of G3 neuroendocrine carcinomas of any origin. Recently, the mammalian target of rapamycin inhibitor everolimus and the combined tyrosine kinase inhibitor sunitinib were registered for the treatment of G1/G2 pancreatic neuroendocrine tumours. The most recent drug treatment recommendations and therapeutic algorithms to improve systemic therapy in patients with neuroendocrine tumours are summarized and novel drug candidates with particular potential for future management of these tumours are outlined. PMID:24058101

Tóth, Miklós

2013-09-29

365

Institutional experience of paediatric high-grade central nervous system tumours: an analysis of 74 patients and review of the literature  

PubMed Central

Aim of the study Although the survival for children with certain central nervous system (CNS) tumour types has improved through current surgical and adjuvant treatment modalities, the prognosis of many high-grade tumours remains poor despite aggressive treatment. The aim of this study is to analyse patients with high-grade brain tumours in our institution to determine the histopathology, clinical characteristics, treatment modalities, and survival. Material and methods A total of 74 patients with a diagnosis of high-grade brain tumour were analysed. There were a total of 31 patients with embryonal tumours, 27 patients with high-grade glial tumours, 12 patients with brain stem gliomas and 4 patients with other high-grade brain tumours. Results There were 48 (65%) boys and 26 (35%) girls (ratio: 1.85) with a median age of 99.7 months (range = 2-204 months). The median follow-up period was 19 months (range = 1-204 months). Tumour recurrence was observed in 38 patients (51.4%). The overall survival rate and event-free survival rate of our patients were 27% and 19.5%, respectively. Conclusions Pediatric high-grade CNS tumours have a very aggressive behaviour and a significant number of children eventually succumb to disease despite multimodal treatment. There is a need of more effective therapeutic approaches for these tumours with poor prognosis. The future improvement in childhood high-grade brain tumour management depends on a better understanding of the molecular genetics and biology of brain tumours.

Oguz, Aynur; Karadeniz, Ceyda; Okur, Arzu; Sarac, Avni; Baykaner, Kemali; Bora, Huseyin; Poyraz, Aylar

2012-01-01

366

Microsatellite instability in thyroid tumours and tumour-like lesions  

Microsoft Academic Search

Fifty-one thyroid tumours and tumour-like lesions were analysed for instability at ten dinucleotide microsatellite loci and at two coding mononucleotide repeats within the transforming growth factor ? (TGF-?) type II receptor (T?RII) and insulin-like growth factor II (IGF-II) receptor (IGFIIR) genes respectively. Microsatellite instability (MI) was detected in 11 out of 51 cases (21.5%), including six (11.7%) with MI at

D Lazzereschi; R Palmirotta; A Ranieri; L Ottini; M C Verì; A Cama; F Cetta; F Nardi; G Colletta; R Mariani-Costantini

1999-01-01

367

Isolated cerebellar tuberculoma mimicking posterior cranial fossa tumour.  

PubMed

Isolated central nervous system (CNS) tuberculoma is a rare disease. This disease is associated with high morbidity and mortality, despite modern methods of detection and treatment. CNS tuberculosis can present as meningitis, arachnoiditis, tuberculomas or the uncommon form of tuberculous subdural empyema and brain abscess. We present the clinical, radiological and pathological findings of cerebellar tuberculoma in an Iranian immunocompetent patient mimicking a malignant tumour. PMID:23966456

Binesh, Fariba; Zahir, Shokouh Taghipour; Bovanlu, Taghi Roshan

2013-08-21

368

Novel use of Empirical Mode Decomposition in single-trial classification of motor imagery for use in brain-computer interfaces.  

PubMed

This paper presents a novel method, based on multi-channel Empirical Mode Decomposition (EMD), of classifying the electroencephalogram (EEG) recordings of imagined movement by a subject within a brain-computer interfacing (BCI) framework. EMD is a technique that divides any non-linear or non-stationary signal into groups of frequency harmonics, called Intrinsic Mode Functions (IMFs). As frequency is a key component of both IMFs and the ? rhythm (8-13 Hz brain activity generated during motor imagery), IMFs are then grouped by frequency. EMD is applied to the recordings from two electrodes for each trial and the resulting IMFs are grouped according to peak-frequency band via Hierarchical Clustering Analysis (HCA). The cluster containing the frequency band of the ? rhythm (8-13 Hz) is then selected and the sum-total of the IMFs from each electrode are summed together. A simple linear classifier is then sufficient to classify the motor-imagery with 89% sensitivity from a separate test set. PMID:24111009

Davies, Simon R H; James, Christopher J

2013-07-01

369

Brain drug delivery technologies: novel approaches for transporting therapeutics  

Microsoft Academic Search

The blood–brain barrier (BBB) denies many therapeutic agents access to brain tumours and other diseases of the central nervous system (CNS). Despite remarkable advances in our understanding of the mechanisms involved in the development of the brain diseases and the actions of neuroactive agents, drug delivery to the brain remains a challenge. For more than 20 years, extensive efforts have

Jamal Temsamani; Jean-Michel Scherrmann; Anthony R Rees; Michel Kaczorek

2000-01-01

370

An update on molecular genetics of gastrointestinal stromal tumours  

PubMed Central

Gastrointestinal stromal tumours (GISTs) are the most common primary mesenchymal tumours of the gastrointestinal tract. Most of them show activating mutations of the genes coding for KIT or platelet?derived growth factor receptor ? (PDGFR?), two receptor tyrosine kinases (RTKs). The RTK inhibitor Imatinib (Gleevec®, Novartis, Switzerland), induces regression of the tumour. The level of response to treatment, together with other clinicopathological parameters is related to the type and site of the activating mutation, thus suggesting that these tumours should be classified according to the molecular context. This is confirmed also by the phenomenon of the resistance to treatment, which arises because of different mechanisms (second mutation, amplification, activation of other RTKs) and can be fought only by specific RTK inhibitors, that are at present under development. RTK activation involves an homogeneous transduction pathway whose components (MAPK, AKT, PI3K, mTOR and RAS) are possible targets of new molecular treatment. A new paradigm of classification integrating the classic pathological criteria with the molecular changes will permit personalised prognosis and treatment.

Tornillo, L; Terracciano, L M

2006-01-01

371

Audit of tumour histopathology reviewed by a regional oncology centre.  

PubMed Central

AIMS--To analyse the diagnostic differences in reporting tumour histopathology between a district general hospital and a regional oncology centre. METHODS--Tumour histopathology reports (n = 227) extracted from Bolton General Hospital files between 1988 and 1992 were compared with the corresponding Christie Hospital (oncology centre) reports, the same material having been seen at both hospitals. RESULTS--Diagnostic agreement existed in 77% of all cases. The incidence of major discrepancies was 8.37%. Of the diagnoses, 19 (36%) cases involved major discrepancies and 34 (64%) cases minor discrepancies. Most discrepancies occurred in the lymphoma group and involved subclassification of Hodgkin's and non-Hodgkin's lymphoma. Ki1 anaplastic large cell lymphoma and T cell rich B cell lymphoma were problematic diagnoses. The correct grading of follicle centre cell lymphomas using the Kiel classification was another problem area. In 19 cases certain aspects of immunohistochemistry produced discrepancies. In one case an incorrect diagnosis was made at the oncology centre and in another both centres gave an incorrect diagnosis. CONCLUSIONS--Areas of diagnostic difficulty mainly involve the subclassification of lymphomas. Review of tumour pathology by experts is recommended, at least in certain categories, to ensure correct diagnosis and uniformity in subclassification of tumours.

Prescott, R J; Wells, S; Bisset, D L; Banerjee, S S; Harris, M

1995-01-01

372

Pericytes: gatekeepers in tumour cell metastasis?  

PubMed

Tumour cells use two major routes to spread during metastasis, e.g. lymph vessels and blood vessels within or surrounding the primary tumour. The growth rate of the primary tumour often correlates with the quantity of new blood vessels that form within the tumour. However, qualitative abnormalities of the tumour vasculature profoundly affect the perfusion of the primary tumour and the escape of tumour cells into the circulation. In this paper, we review recent evidence for a novel role of the supporting mural cells in limiting blood-borne metastasis. PMID:17891366

Gerhardt, Holger; Semb, Henrik

2007-09-22

373

Ablative therapy for liver tumours  

PubMed Central

Established ablative therapies for the treatment of primary and secondary liver tumours, including percutaneous ethanol injection, cryotherapy, and radiofrequency ablation, are discussed. Newer techniques such as magnetic resonance imaging guided laser interstitial thermal therapy of liver tumours has produced a median survival rate of 40.8 months after treatment. The merits of this newly emerging technique are discussed, together with future developments, such as focused ultrasound therapy, which holds the promise of non-invasive thermoablation treatment on an outpatient basis.

Dick, E A; Taylor-Robinson, S D; Thomas, H C; Gedroyc, W M W

2002-01-01

374

Retroperitoneal tumours: review of management  

PubMed Central

INTRODUCTION The retroperitoneum can host a wide spectrum of pathologies, including a variety of rare benign tumours and malignant neoplasms that can be either primary or metastatic lesions. Retroperitoneal tumours can cause a diagnostic dilemma and present several therapeutic challenges because of their rarity, relative late presentation and anatomical location, often in close relationship with several vital structures in the retroperitoneal space. MATERIALS AND METHODS A comprehensive literature search was conducted using PubMed. Relevant international articles published in the last ten years were assessed. The keywords for search purposes included: retroperitoneum, benign, sarcoma, neoplasm, diagnosis and surgery, radiotherapy, chemotherapy. The search was limited to articles published in English. All articles were read in full by the authors and selected for inclusion based on relevance to this article. RESULTS Tumours usually present late and cause symptoms or become palpable once they have reached a significant size. Retroperitoneal tumours are best evaluated with good quality cross-sectional imaging and preoperative histology by core needle biopsy is required when imaging is non-diagnostic. Sarcomas comprise a third of retroperitoneal tumours. Other retroperitoneal neoplasms include lymphomas and epithelial tumours or might represent metastatic disease from known or unknown primary sites. The most common benign pathologies encountered in the retroperitoneum include benign neurogenic tumours, paragangliomas, fibromatosis, renal angiomyolipomas and benign retroperitoneal lipomas. CONCLUSIONS Complete surgical resection is the only potential curative treatment modality for retroperitoneal sarcomas and is best performed in high-volume centres by a multidisciplinary sarcoma team. The ability completely to resect a retroperitoneal sarcoma and tumour grade remain the most important predictors of local recurrence and disease-specific survival.

Strauss, Dirk C; Hayes, Andrew J; Thomas, J Meirion

2011-01-01

375

Nitric oxide synthase is expressed in experimental malignant glioma and influences tumour blood flow.  

PubMed

The distribution and function of nitric oxide synthase (NOS) was studied in the rodent C6 implantation glioma model. Using a histochemical stain for NADPH diaphorase, which colocalises with NOS, morphological studies revealed non homogenous staining of the constituent tumour cells and the neoplastic endothelium. Immunocytochemical staining for macrophages (ED1, ED2) showed dense positivity at the tumour brain interface with more patchy positivity within the tumour mass. This finding suggests that both macrophages, which are known to produce large amounts of NO, and the C6 cells contribute to the NADPH diaphorase positivity. Administration of the NOS inhibitor Ng-nitro-L-argine methyl ester (L-NAME) significantly reduced both tumour (40%) and contralateral local cerebral blood flow (20%) compared to control animals. These findings demonstrate that (i) NOS is present in experimental malignant glioma; (ii) NO mediated mechanisms contribute to tumour blood vessel dilatation and blood flow regulation; and (iii) using this model there is a significant differential sensitivity of the tumour and brain parenchymal vascular beds to a NOS inhibitor. Further investigations are required to determine the potential therapeutic and biological relevance of these findings and the relative contributions of tumour cells, neoplastic endothelium and reactive macrophages to NO mechanism in gliomas. PMID:8869716

Whittle, I R; Collins, F; Kelly, P A; Ritchie, I; Ironside, J W

1996-01-01

376

Orthotopic human melanoma xenograft model systems for studies of tumour angiogenesis, pathophysiology, treatment sensitivity and metastatic pattern.  

PubMed Central

Adequate tumour models are a prerequisite in experimental cancer research. The purpose of the present work was to establish and assess the validity of four new orthotopic human melanoma xenograft model systems (A-07, D-12, R-18, U-25). Permanent cell lines were established in monolayer culture from subcutaneous metastases of four different melanoma patients by using an in vivo-in vitro procedure, and cells from these lines were inoculated intradermally in Balb/c nu/nu mice to form tumours. Individual xenografted tumours of the same line differed substantially in growth and pathophysiological parameters, probably as a consequence of differences between inoculation sites in host factors which influence tumour angiogenesis. Nevertheless, xenografted tumours of different lines showed distinctly different biological characteristics. Several biological characteristics of the donor patients' tumours were retained in the xenografted tumours, including angiogenic potential; growth, histopathological and pathophysiological parameters; and sensitivity to radiation, heat and dacarbazine treatment. Moreover, the organ-specific metastatic pattern of the xenografted tumours reflected the pattern of distant metastases in the donor patients. The organs of preference for distant metastases were lungs (A-07, D-12), lymph nodes (R-18) and brain (U-25). R-18 lymph node metastases and U-25 brain metastases developed in the absence of lung involvement. The four orthotopic human melanoma xenograft model systems show great promise for future studies of tumour angiogenesis, pathophysiology, treatment sensitivity and metastatic pattern. Images Figure 1 Figure 4 Figure 5 Figure 7

Rofstad, E. K.

1994-01-01

377

Echocardiographic pattern of right atrial tumour motion.  

PubMed Central

Propagation of Wilm's tumour to the right atrium was diagnosed by echocardiography. The tumour prolapsed into the right ventricle during each atrial systole. The presence of the tumour and its motion were confirmed by cardiac catheterization, cineangiography, and surgical exploration. Successful resection of the tumour was accomplished. Echocardiography was helpful in detecting the presence of the right atrial tumour and accurately reflected the pattern of its atrioventricular motion. Images

Farooki, Z Q; Green, E W; Arciniegas, E

1976-01-01

378

Brain metastasis from medullary thyroid carcinoma  

PubMed Central

The brain is an exceedingly rare site of metastasis in medullary thyroid carcinoma (MTC). A 50-year-old female who had a history of micro-MTC 11 years prior developed a cerebellar metastasis which was incidentally discovered. Imaging revealed a right cerebellar hemispheric mass with contrast enhancement on CT scans. Histopathologic exam demonstrated a metastatic tumour composed of nodules and sheets of large tumour cells with abundant cytoplasm. Immunohistochemistry confirmed the origin from a MTC. This case report highlights the unique features of an unusual metastatic brain tumour, which followed an indolent course for a long time despite multiple distant metastases.

Borcek, P; Asa, S L; Gentili, F; Ezzat, S; Kiehl, T-R

2010-01-01

379

Choice of tumour markers in patients with neuroendocrine tumours is dependent on the histological grade. A marker study of Chromogranin A, Neuron specific enolase, Progastrin-releasing peptide and cytokeratin fragments  

Microsoft Academic Search

BackgroundChromogranin A (CgA) is the most important tumour marker for well-differentiated neuroendocrine tumours (NET) and neuron specific enolase (NSE) for poorly differentiated neuroendocrine carcinoma (NEC). This study investigated whether the markers progastrin-releasing peptide (proGRP) and cytokeratin fragments (CKfr) CK8, CK18 and CK19 (MonoTotal®) can be of additional value to the histological classification and help predict survival in these patients.

Catharina M. Korse; Babs G. Taal; Andrew Vincent; Marie-Louise F. van Velthuysen; Paul Baas; Johanna C. G. M. Buning-Kager; Theodora C. Linders; Johannes M. G. Bonfrer

380

Application of Data Mining Techniques for Medical Image Classification  

Microsoft Academic Search

Breast cancer represents the second leading cause of cancer deaths in women today and it is the most common type of cancer in women. This paper presents some experiments for tumour detection in digital mammography. We inves- tigate the use of different data mining techniques, neural networks and association rule mining, for anomaly detec- tion and classification. The results show

Maria-luiza Antonie; Osmar R. Zaïane; Alexandru Coman

2001-01-01

381

Microsatellite instability in thyroid tumours and tumour-like lesions.  

PubMed

Fifty-one thyroid tumours and tumour-like lesions were analysed for instability at ten dinucleotide microsatellite loci and at two coding mononucleotide repeats within the transforming growth factor beta (TGF-beta) type II receptor (TbetaRII) and insulin-like growth factor II (IGF-II) receptor (IGFIIR) genes respectively. Microsatellite instability (MI) was detected in 11 out of 51 cases (21.5%), including six (11.7%) with MI at one or two loci and five (9.8%) with MI at three or more loci (RER+ phenotype). No mutations in the TbetaRII and IGFIIR repeats were observed. The overall frequency of MI did not significantly vary in relation to age, gender, benign versus malignant status and tumour size. However, widespread MI was significantly more frequent in follicular adenomas and carcinomas than in papillary and Hürthle cell tumours: three out of nine tumours of follicular type (33.3%) resulted in replication error positive (RER+), versus 1 out of 29 papillary carcinomas (3.4%, P = 0.01), and zero out of eight Hürthle cell neoplasms. Regional lymph node metastases were present in five MI-negative primary cancers and resulted in MI-positive in two cases. PMID:9888478

Lazzereschi, D; Palmirotta, R; Ranieri, A; Ottini, L; Verì, M C; Cama, A; Cetta, F; Nardi, F; Colletta, G; Mariani-Costantini, R

1999-01-01

382

Microsatellite instability in thyroid tumours and tumour-like lesions  

PubMed Central

Fifty-one thyroid tumours and tumour-like lesions were analysed for instability at ten dinucleotide microsatellite loci and at two coding mononucleotide repeats within the transforming growth factor ? (TGF-?) type II receptor (T?RII) and insulin-like growth factor II (IGF-II) receptor (IGFIIR) genes respectively. Microsatellite instability (MI) was detected in 11 out of 51 cases (21.5%), including six (11.7%) with MI at one or two loci and five (9.8%) with Ml at three or more loci (RER+ phenotype). No mutations in the T?RII and IGFIIR repeats were observed. The overall frequency of MI did not significantly vary in relation to age, gender, benign versus malignant status and tumour size. However, widespread MI was significantly more frequent in follicular adenomas and carcinomas than in papillary and Hürthle cell tumours: three out of nine tumours of follicular type (33.3%) resulted in replication error positive (RER+), versus 1 out of 29 papillary carcinomas (3.4%, P = 0.01), and zero out of eight Hürthle cell neoplasms. Regional lymph node metastases were present in five MI-negative primary cancers and resulted in MI-positive in two cases. © 1999 Cancer Research Campaign

Lazzereschi, D; Palmirotta, R; Ranieri, A; Ottini, L; Veri, M C; Cama, A; Cetta, F; Nardi, F; Colletta, G; Mariani-Costantini, R

1999-01-01

383

Constraint Classification for Multiclass Classification and Ranking  

Microsoft Academic Search

The constraint classification framework captures many flavors of mul- ticlass classification including winner-take-all multiclass classification, multilabel classification and ranking. We present a meta-algorithm for learning in this framework that learns via a single linear classifier in high dimension. We discuss distribution independent as well as margin-based generalization bounds and present empirical and theoretical evidence showing that constraint classification benefits over

Sariel Har-peled; Dan Roth; Dav Zimak

2002-01-01

384

Childhood Adrenocortical Tumours: a Review  

PubMed Central

Childhood adrenocortical tumour (ACT) is not a common disease, but in southern Brazil the prevalence is 15 times higher than in other parts of the world. One hundred and thirty-seven patients have been identified and followed by our group over the past four decades. Affected children are predominantly girls, with a female-to-male ratio of 3.5:1 in patients below 4 years of age. Virilization alone (51.6%) or mixed with Cushing's syndrome (42.0%) was the predominant clinical picture observed in these patients. Tumours are unilateral, affecting both glands equally. TP53 R337H germline mutations underlie most childhood ACTs in southern Brazil. Epidemiological data from our casuistic studies revealed that this mutation has ~10% penetrance for ACT. Surgery is the definitive treatment, and a complete resection should always be attempted. Although adjuvant chemotherapy has shown some encouraging results, its influence on overall outcome is small. The survival rate is directly correlated to tumour size; patients with small, completely excised tumours have survival rates close to 90%, whereas in those patients with inoperable tumours and/or metastatic disease it is less than 10%. In the group of patients with large, excisable tumours, half of them have an intermediate outcome. Recent molecular biology techniques and genomic approaches may help us to better understand the pathogenesis of ACT, the risk of developing a tumour when TP53 R337H is present, and to predict its outcome. An ongoing pilot study consisting of close monitoring of healthy carriers of the TP53 R337H mutation - siblings and first-degree relatives of known affected cases - aims at the early detection of ACTs and an improvement of the cure rate.

2006-01-01

385

Neural-network-based classification of cognitively normal, demented, Alzheimer disease and vascular dementia from single photon emission with computed tomography image data from brain.  

PubMed Central

Single photon emission with computed tomography (SPECT) hexamethylphenylethyleneamineoxime technetium-99 images were analyzed by an optimal interpolative neural network (OINN) algorithm to determine whether the network could discriminate among clinically diagnosed groups of elderly normal, Alzheimer disease (AD), and vascular dementia (VD) subjects. After initial image preprocessing and registration, image features were obtained that were representative of the mean regional tissue uptake. These features were extracted from a given image by averaging the intensities over various regions defined by suitable masks. After training, the network classified independent trials of patients whose clinical diagnoses conformed to published criteria for probable AD or probable/possible VD. For the SPECT data used in the current tests, the OINN agreement was 80 and 86% for probable AD and probable/possible VD, respectively. These results suggest that artificial neural network methods offer potential in diagnoses from brain images and possibly in other areas of scientific research where complex patterns of data may have scientifically meaningful groupings that are not easily identifiable by the researcher. Images Fig. 1

deFigueiredo, R J; Shankle, W R; Maccato, A; Dick, M B; Mundkur, P; Mena, I; Cotman, C W

1995-01-01

386

Canine Mammary Mixed Tumours: A Review  

PubMed Central

Mammary mixed tumours are the most frequent neoplasias in female dogs. In humans, mixed tumours are frequently found in the salivary glands and are known as pleomorphic adenomas. In addition to their histomorphologic similarities, mixed tumours and pleomorphic adenomas have the potential to become malignant and give rise to carcinomas in mixed tumours and carcinomas ex-pleomorphic adenoma, respectively. The factors associated with malignant transformation are still poorly known in the case of canine mixed tumours. However, this form of neoplasia tends to be associated with a better prognosis than other malignant histological types. This paper discusses the main features associated with female canine mammary mixed tumours.

Dantas Cassali, Geovanni; Cavalheiro Bertagnolli, Angelica; Ferreira, Enio; Araujo Damasceno, Karine; de Oliveira Gamba, Conrado; Bonolo de Campos, Cecilia

2012-01-01

387

Tumour-associated eosinophilia: a review.  

PubMed Central

In a recent study of cervical carcinoma, 13 cases with a marked eosinophil infiltrate around the tumour were found. The histological appearance of the tumours was distinctive and suggested a specific response, similar to the lymphocyte infiltration in medullary carcinoma of the breast and seminoma. A review of published reports shows that tumour-associated tissue eosinophilia (TATE) and tumour-associated blood eosinophilia (TABE) may be seen in tumours of different histological types from different anatomical sites, and may occur together or separately. Tumours with TATE alone appear to have a better prognosis that those without, while TABE is associated with tumor spread and a poor prognosis. Images

Lowe, D; Jorizzo, J; Hutt, M S

1981-01-01

388

Lymphocytic tumours of the conjunctiva  

PubMed Central

Twenty-six cases of lymphocytic tumour of the conjunctiva, which were originally classified as benign lymphoma and lymphosarcoma, were followed up for more than five years, They were then reclassified into non-disseminating and disseminating groups. Only when germinal follicles are present can a histological diagnosis of benign lymphoma be made. Moreover, it is only when lymphoblasts are seen to be infiltrating the tissues that a definitive diagnosis of lymphosarcoma can be made. The remaining tumours, which represent the large majority of lesions, show a very similar or identical histological picture, and a diagnosis of benignity or malignancy can only be made after a prolonged follow up. The possible nature of the non-disseminating lymphocytic tumours is briefly discussed. Images

Morgan, Gwyn

1971-01-01

389

Monoclonal antibodies in solid tumours.  

PubMed

Monoclonal antibodies (mAbs) have become an integral part of therapeutic strategies used to treat solid tumours. Directed against membrane-bound receptors or extracellular ligands with high specificity, they target elements upstream in the signal transduction pathways that contribute to malignant growth, proliferation, survival, angiogenesis and spread. Several mAbs have now received regulatory approval - trastuzumab, cetuximab, panitumumab, bevacizumab and catumaxomab-across multiple solid tumour types, including breast, colorectal, and non-small cell lung cancers, amongst others. Despite these successes there have been ample disappointments, which in turn is stimulating ongoing research and development efforts. Nevertheless, greater initiative and vision in this development process is needed, from intelligent compound design to enrichment of patient populations during clinical development, biomarker discovery and ultimately tailored, individualised treatment decisions. In this commentary we review those mAbs now in routine use for solid tumours, interesting aspects of their use and future directions. PMID:20406174

Markman, Ben; Tabernero, Josep

2010-08-01

390

Inhibition in multiclass classification.  

PubMed

The role of inhibition is investigated in a multiclass support vector machine formalism inspired by the brain structure of insects. The so-called mushroom bodies have a set of output neurons, or classification functions, that compete with each other to encode a particular input. Strongly active output neurons depress or inhibit the remaining outputs without knowing which is correct or incorrect. Accordingly, we propose to use a classification function that embodies unselective inhibition and train it in the large margin classifier framework. Inhibition leads to more robust classifiers in the sense that they perform better on larger areas of appropriate hyperparameters when assessed with leave-one-out strategies. We also show that the classifier with inhibition is a tight bound to probabilistic exponential models and is Bayes consistent for 3-class problems. These properties make this approach useful for data sets with a limited number of labeled examples. For larger data sets, there is no significant comparative advantage to other multiclass SVM approaches. PMID:22594829

Huerta, Ramón; Vembu, Shankar; Amigó, José M; Nowotny, Thomas; Elkan, Charles

2012-05-17

391

Molecular aspects of tumour hypoxia.  

PubMed

Hypoxia is an important feature of the microenvironment of a wide range of solid tumours. Its critical role in radio- and chemoresistance and its significance as an adverse prognostic factor have been well established over the last decades. On a cellular level, hypoxia evokes a complex molecular response with a central role for the HIF-1 pathway. The cellular processes under control of HIF-1 contain important prognostic information and comprise potential candidates for directing hypoxia-modifying therapies. This review will provide an overview of the current knowledge on the molecular aspects of tumour hypoxia and the link to clinical practice. PMID:19383328

Rademakers, Saskia E; Span, Paul N; Kaanders, Johannes H A M; Sweep, Fred C G J; van der Kogel, Albert J; Bussink, Johan

2008-03-27

392

The semaphorins: versatile regulators of tumour progression and tumour angiogenesis  

Microsoft Academic Search

The semaphorins and their receptors, the neuropilins and the plexins, were originally characterized as constituents of the complex regulatory system responsible for the guidance of axons during the development of the central nervous system. However, a growing body of evidence indicates that various semaphorins can either promote or inhibit tumour progression through the promotion or inhibition of processes such as

Ofra Kessler; Gera Neufeld

2008-01-01

393

Classification Management Tutorial.  

National Technical Information Service (NTIS)

The purpose of this Classification Management tutorial is to provide detailed supplemental guidance to Original Classification Authorities (OCAs) for the development of United States (US) Army security classification guides (SCGs) or guidance. Army Regula...

2006-01-01

394

Peripheral mucoepidermoid tumour of the lung.  

PubMed Central

Mucoepidermoid tumours of the bronchial tree are uncommon neoplasms, which are believed to arise from terminal ducts of the proximal tracheobronchial tree. The first case of a peripheral mucoepidermoid tumour of the lung is reported. Images

Green, L. K.; Gallion, T. L.; Gyorkey, F.

1991-01-01

395

Stereotactic fractionated radiotherapy for Klatskin tumours  

Microsoft Academic Search

Background and purposeIn spite of various efforts perihilar cholangiocellular carcinoma (Klatskin tumour) has still a bad prognosis. The treatment of patients with inoperable Klatskin tumours by stereotactic fractionated radiotherapy (SFRT) was analysed retrospectively.

Felix Momm; Eva Schubert; Karl Henne; Norbert Hodapp; Hermann Frommhold; Jan Harder; Anca-Ligia Grosu; Gerhild Becker

2010-01-01

396

Effects of Day-to-Day Variability of Physiological Data on Operator Functional State Classification.  

National Technical Information Service (NTIS)

The application of pattern classification techniques to physiological data has undergone rapid expansion. Tasks as varied as the diagnosis of disease from magnetic resonance images, brain-computer interfaces for the disabled, and the decoding of brain fun...

C. A. Russell G. F. Wilson J. C. Christensen J. R. Estepp K. M. Thomas

2013-01-01

397

Maltoma of thyroid: a rare thyroid tumour.  

PubMed

Introduction. Primary thyroid lymphomas constitute up to 5% of all thyroid malignancies and can be divided into non-Hodgkin's lymphomas (NHLs) of B- and T-cell types, as well as Hodgkin's lymphomas. Mucosa-associated lymphoid tissue (MALT) lymphomas are a relatively recently recognized subset of B-cell NHLs, and they are listed as extranodal marginal zone lymphomas according to the revised European-American lymphoma classification. Case Report. We report an uncommon case of a 44-year-old man, who noted a painless, growing mass on right side of his neck of the three-month duration. Thyroid profile was within normal limits. FNAC showed lymphocytic thyroiditis. The patient underwent a right hemithyroidectomy. The histologic examination and the immunohistochemistry showed an extra nodal marginal B-cell type maltoma (malt lymphoma). CHOP chemotherapy with rituximab was given. The clinical course has been favourable in the first year of followup, with no evidence of local or systemic recurrence of the disease. Discussion. Marginal zone lymphoma encompasses a heterogeneous group of B-cell tumours that variously arise within the lymph nodes, spleen, or extranodal tissues. A case of maltoma of thyroid is presented for its rarity and diagnostic dilemmas. Conclusion. Maltomas are slow-growing lymphomas. The optimal treatment and followup of patients with thyroid maltomas remain controversial at present. PMID:23476858

Latheef, Navisha; Shenoy, Vijendra; Kamath, M Panduranga; Hegde, Mahesh Chandra; Rao, A Raghavendra

2013-02-11

398

Maltoma of Thyroid: A Rare Thyroid Tumour  

PubMed Central

Introduction. Primary thyroid lymphomas constitute up to 5% of all thyroid malignancies and can be divided into non-Hodgkin's lymphomas (NHLs) of B- and T-cell types, as well as Hodgkin's lymphomas. Mucosa-associated lymphoid tissue (MALT) lymphomas are a relatively recently recognized subset of B-cell NHLs, and they are listed as extranodal marginal zone lymphomas according to the revised European-American lymphoma classification. Case Report. We report an uncommon case of a 44-year-old man, who noted a painless, growing mass on right side of his neck of the three-month duration. Thyroid profile was within normal limits. FNAC showed lymphocytic thyroiditis. The patient underwent a right hemithyroidectomy. The histologic examination and the immunohistochemistry showed an extra nodal marginal B-cell type maltoma (malt lymphoma). CHOP chemotherapy with rituximab was given. The clinical course has been favourable in the first year of followup, with no evidence of local or systemic recurrence of the disease. Discussion. Marginal zone lymphoma encompasses a heterogeneous group of B-cell tumours that variously arise within the lymph nodes, spleen, or extranodal tissues. A case of maltoma of thyroid is presented for its rarity and diagnostic dilemmas. Conclusion. Maltomas are slow-growing lymphomas. The optimal treatment and followup of patients with thyroid maltomas remain controversial at present.

Latheef, Navisha; Shenoy, Vijendra; Kamath, M. Panduranga; Hegde, Mahesh Chandra; Rao, A. Raghavendra

2013-01-01

399

Fluorescence-guided surgical sampling of glioblastoma identifies phenotypically distinct tumour-initiating cell populations in the tumour mass and margin  

PubMed Central

Background: Acquiring clinically annotated, spatially stratified tissue samples from human glioblastoma (GBM) is compromised by haemorrhage, brain shift and subjective identification of ‘normal' brain. We tested the use of 5-aminolevulinic acid (5-ALA) fluorescence to objective tissue sampling and to derive tumour-initiating cells (TICs) from mass and margin. Methods: The 5-ALA was administered to 30 GBM patients. Samples were taken from the non-fluorescent necrotic core, fluorescent tumour mass and non-fluorescent margin. We compared the efficiency of isolating TICs from these areas in 5-ALA versus control patients. HRMAS 1H NMR was used to reveal metabolic alterations due to 5-ALA. We then characterised TICs for self-renewal in vitro and tumorigenicity in vivo. Results: The derivation of TICs was not compromised by 5-ALA and the metabolic profile was similar between tumours from 5-ALA patients and controls. The TICs from the fluorescent mass were self-renewing in vitro and tumour-forming in vivo, whereas TICs from non-fluorescent margin did not self-renew in vitro but did form tumours in vivo. Conclusion: Our data show that 5-ALA does not compromise the derivation of TICs. It also reveals that the margin contains TICs, which are phenotypically different from those isolated from the corresponding mass.

Piccirillo, S G M; Dietz, S; Madhu, B; Griffiths, J; Price, S J; Collins, V P; Watts, C

2012-01-01

400

Magnetic resonance imaging of primary tumours and tumour-like lesions of bone  

Microsoft Academic Search

The experience with magnetic resonance imaging (MRI) of 81 patients with primary bone tumours and tumour-like lesions is reported. MRI proved to be a sensitive method of detecting primary bone tumours. Intramedullary and extraosseous parts of bone tumours were, delineated better than by plain films and computed tomography (CT). Surgical clips and Harrington rods did not appreciably limit the estimation

K. Bohndorf; M. Reiser; B. Lochner; W. Féaux de Lacroix; W. Steinbrich

1986-01-01

401

Chromosomal organization of Drosophila tumours  

Microsoft Academic Search

In otu mutants of Drosophila melanogaster ovarian tumours develop because of the high mitotic activity of the mutant cystocytes; the latter are normally endopolyploid. In certain alleles of otu, however, a varying proportion of the mutant ovarian cystocytes undergo polyteny. Mutant cystocytes with polytene chromosomes are termed pseudonurse cells (PNC). Polytene chromosome morphology and banding patterns in PNC of otu1\\/otu3

P. Sinha; Arati Mishra; S. C. Lakhotia

1987-01-01

402

Wilms' tumour: trials and tribulation.  

PubMed

Surgery, radiotherapy and chemotherapy are currently the basis of multimodal treatment of Wilms' tumor. Surgery plays the central role in the management of this tumour and will cure 25% of patients if employed alone. Surgical mortality has been reduced to 1.5% at major centres and the most dangerous intra-operative complication is a venacaval tumour embolising into the pulmonary artery. Patients found to be initially inoperable who then have local and systemic therapy, followed by successful secondary surgery, have a reduced survival rate. Definite statements on bilateral tumours are difficult to make. The most fundamental determinants of survival are the histological characteristics of the tumour and the stage of the disease at presentation. Just as the quality of surgery has improved, so have radiotherapy techniques been refined. However, radiotherapy has been replaced by chemotherapy in many instances. The advent of chemotherapy has added to clinical success with a further improvement of survival figures by 25%. Chemotherapy is most effective in controlling micrometastases. However, it must be remembered that the treatment is toxic and needs skillful handling and modification. PMID:2536483

Gough, D C

1989-01-01

403

Lifestyle issues and genitourinary tumours  

Microsoft Academic Search

A variety of lifestyle factors, including physical activity, artificial sweeteners, alcohol consumption and smoking, have been reported to contribute to the risk of developing urological malignancies. A great number of epidemiological studies suggest that sports and physical activity may have a preventive influence on genitourinary tumours, especially on the incidence of prostate cancer. Smoking appears to be the most relevant

Frank Sommer; Theo Klotz; Bernd J. Schmitz-Dräger

2004-01-01

404

Drug penetration in solid tumours  

Microsoft Academic Search

To be most effective anticancer drugs must penetrate tissue efficiently, reaching all the cancer cells that comprise the target population in a concentration sufficient to exert a therapeutic effect. Most research into the resistance of cancers to chemotherapy has concentrated on molecular mechanisms of resistance, whereas the role of limited drug distribution within tumours has been neglected. We summarize the

Andrew I. Minchinton; Ian F. Tannock

2006-01-01

405

Primary intracranial germ cell tumours  

Microsoft Academic Search

A histological study has been made of a retrospective series of 17 primary intracranial germ cell tumours found in a collection of 3550 intracranial neoplasms (incidence of 0.48%). All, except for two differentiated teratomas (one extracerebral in a neonate and another in the lateral ventricle), were situated in the midline in persons aged 5 to 37 years (13 males, 4

K. Jellinger

1973-01-01

406

Surgical treatment of Pancoast tumours  

Microsoft Academic Search

Due to its localisation in the apex of the lung with invasion of the lower part of the brachial plexus, first ribs, vertebrae, subclavian vessels or stellate ganglion, a superior sulcus tumour causes characteristic symptoms, like arm or shoulder pain or Horner's syndrome. If rib invasion is the only feature, lysis of the rib must be evident on the chest

Cordula C. M Pitz; Aart Brutel de la Rivière; Henry A van Swieten; Vincent A. M Duurkens; Jan-Willem J Lammers; Jules M. M van den Bosch

2004-01-01

407

Surgical treatment of Pancoast tumours  

Microsoft Academic Search

Summary Due to its localisation in the apex of the lung with invasion of the lower part of the brachial plexus, first ribs, vertebrae, subclavian vessels or stellate ganglion, a superior sulcus tumour causes characteristic symptoms, like arm or shoulder pain or Horner's syndrome. If rib invasion is the only feature, lysis of the rib must be evident on the

Cordula C. M. Pitz; Henry A. van Swieten; Vincent A. M. Duurkens; Jan-Willem J. Lammers

408

[Subcutaneous tumour in an adolescent].  

PubMed

A 13-year-old adolescent presented with an enlarging subcutaneous mass beneath the right eyebrow. Clinically suspicious for dermoid cyst or pilomatrixoma, it was decided to remove the tumour completely. Based on histopathological examination the diagnosis of intravascular papillary endothelial hyperplasia (IPEH) was made. Histopathological features are discussed with regard to the possible pathogenesis. PMID:20393725

Herwig, M C; Wabbels, B; Holz, F G; Loeffler, K U

2010-07-01

409

Interventional Treatment of Gastrointestinal Neuroendocrine Tumours  

Microsoft Academic Search

Neuroendocrine (NE) tumours of the gastrointestinal tract (carcinoids and endocrine pancreatic tumours) are rare diseases. In the presence of liver metastases these patients may suffer from disabling symptoms due to hormone overproduction. Patients with localized disease can be resected for cure and also patients with liver metastases can undergo potentially curative tumour resection. However, long-term follow-up of the latter cases

H. Ahlman; B. Wängberg; S. Jansson; S. Friman; M. Olausson; U. Tylén; O. Nilsson

2000-01-01

410

Management of Non-Epithelial Ovarian Tumours  

Microsoft Academic Search

Ovarian tumours of non-epithelial origin are less common than those of epithelial origin but must be distinguished from these as their natural history and management differ. As these tumours are rare, histological review by an expert in the field is essential. There have been no randomised trials to outline the management of these tumours and therefore this paper represents a

John A. Bridgewater; Gordon J. S. Rustin

1999-01-01

411

Optimization of Tumour Therapy with Ionizing Radiations.  

National Technical Information Service (NTIS)

The results of tumour therapy with ionizing radiation seem not to be optimal since the tumour cells are less damaged than the normal tissue due to the lack of oxygen and the tumour cells also are able to repair much of the radiation damage. From this reas...

W. Pohlit

1980-01-01

412

Colonic Gastrointestinal Stromal Tumour Presenting as Intussusception  

PubMed Central

Gastrointestinal stromal tumours (GIST) are rare in paediatric patients and have a discrete clinicopathological and molecular divergence from that observed in adults. In the present report we present a case of a 2-month-old female in whom colonic gastrointestinal stromal tumour acted as a lead point of colocolic intussusception. Laparoscopically assisted reduction of the intussusception and resection of tumour was done.

Goel, Garima; Sobti, Parul; Khurana, Nita; Mathur, Mohit; Sinha, Shandip K; Aggarwal, Satish K

2013-01-01

413

Tumour stem cells and drug resistance  

Microsoft Academic Search

The contribution of tumorigenic stem cells to haematopoietic cancers has been established for some time, and cells possessing stem-cell properties have been described in several solid tumours. Although chemotherapy kills most cells in a tumour, it is believed to leave tumour stem cells behind, which might be an important mechanism of resistance. For example, the ATP-binding cassette (ABC) drug transporters

Tito Fojo; Susan Bates; Michael Dean

2005-01-01

414

The MEN1 Gene and Pituitary Tumours  

Microsoft Academic Search

Sporadic multiple endocrine neoplasia type 1 (MEN1) is defined as the occurrence of tumours in two of three main endocrine tissue types: parathyroid, pituitary and pancreaticoduodenal. A prolactinoma variant or Burin variant of MEN1 was found to occur in three large kindreds, with more prolactinomas and fewer gastrinomas than typical MEN1. MEN1 tumours differ from common tumours by showing features

Sunita K. Agarwal; Atsushi Ozawa; Carmen M. Mateo; Stephen J. Marx

2009-01-01

415

Increasing occurence of tumour cell — Tumour cell emperipolesis in the regenerating JB1 ascites tumour  

Microsoft Academic Search

During the investigation of JB-1 ascites tumour cells in recurrent growth several cases of emperipolesis were observed. Different types of emperipolesis are presented. Light microscopical serial sections, autoradiography and transmission electron microscopy indicate that the cells involved in emperipolesis are separate cells, and the authors suggest that cytophagocytosis is the initial mechanism in the development of emperipolesis.

J. Chemnitz; P. Skaaring; P. Bichel

1975-01-01

416

Adaptive, template moderated, spatially varying statistical classification.  

PubMed

A novel image segmentation algorithm was developed to allow the automatic segmentation of both normal and abnormal anatomy from medical images. The new algorithm is a form of spatially varying statistical classification, in which an explicit anatomical template is used to moderate the segmentation obtained by statistical classification. The algorithm consists of an iterated sequence of spatially varying classification and nonlinear registration, which forms an adaptive, template moderated (ATM), spatially varying statistical classification (SVC). Classification methods and nonlinear registration methods are often complementary, both in the tasks where they succeed and in the tasks where they fail. By integrating these approaches the new algorithm avoids many of the disadvantages of each approach alone while exploiting the combination. The ATM SVC algorithm was applied to several segmentation problems, involving different image contrast mechanisms and different locations in the body. Segmentation and validation experiments were carried out for problems involving the quantification of normal anatomy (MRI of brains of neonates) and pathology of various types (MRI of patients with multiple sclerosis, MRI of patients with brain tumors, MRI of patients with damaged knee cartilage). In each case, the ATM SVC algorithm provided a better segmentation than statistical classification or elastic matching alone. PMID:10972320

Warfield, S K; Kaus, M; Jolesz, F A; Kikinis, R

2000-03-01

417

Targeting hypoxic tumour cells to overcome metastasis  

PubMed Central

The microenvironment within solid tumours can influence the metastatic dissemination of tumour cells, and recent evidence suggests that poorly oxygenated (hypoxic) cells in primary tumours can also affect the survival and proliferation of metastatic tumour cells in distant organs. Hypoxic tumour cells have been historically targeted during radiation therapy in attempts to improve loco-regional control rates of primary tumours since hypoxic cells are known to be resistant to ionizing radiation-induced DNA damage. There are, therefore, a number of therapeutic strategies to directly target hypoxic cells in primary (and metastatic) tumours, and several compounds are becoming available to functionally inhibit hypoxia-induced proteins that are known to promote metastasis. This mini-review summarizes several established and emerging experimental strategies to target hypoxic cells in primary tumours with potential clinical application to the treatment of patients with tumour metastases or patients at high risk of developing metastatic disease. Targeting hypoxic tumour cells to reduce metastatic disease represents an important advance in the way scientists and clinicians view the influence of tumour hypoxia on therapeutic outcome.

2011-01-01

418

21 CFR 882.1935 - Near Infrared (NIR) Brain Hematoma Detector.  

Code of Federal Regulations, 2013 CFR

... Near Infrared (NIR) Brain Hematoma Detector. ...Near Infrared (NIR) Brain Hematoma Detector is...to evaluate suspected brain hematomas. (b) Classification...special controls). The special controls for this...distribution, and use of this device are...

2013-04-01

419

Cellular Immortality in Brain Tumors: An Overview  

Microsoft Academic Search

\\u000a Brain tumors are a diverse group of neoplasms that continue to present a formidable challenge in our attempt to achieve cures\\u000a and a reduction in morbidity. Our conceptual framework of human brain cancer has been redrawn in the current decade. There\\u000a is a growing acceptance that brain tumour formation is a phenotypic outcome of dysregulated neurogenesis, with tumors viewed\\u000a as

Ruman Rahman; Richard G. Grundy

420

Mobile phones and head tumours. The discrepancies in cause-effect relationships in the epidemiological studies - how do they arise?  

PubMed Central

Background Whether or not there is a relationship between use of mobile phones (analogue and digital cellulars, and cordless) and head tumour risk (brain tumours, acoustic neuromas, and salivary gland tumours) is still a matter of debate; progress requires a critical analysis of the methodological elements necessary for an impartial evaluation of contradictory studies. Methods A close examination of the protocols and results from all case-control and cohort studies, pooled- and meta-analyses on head tumour risk for mobile phone users was carried out, and for each study the elements necessary for evaluating its reliability were identified. In addition, new meta-analyses of the literature data were undertaken. These were limited to subjects with mobile phone latency time compatible with the progression of the examined tumours, and with analysis of the laterality of head tumour localisation corresponding to the habitual laterality of mobile phone use. Results Blind protocols, free from errors, bias, and financial conditioning factors, give positive results that reveal a cause-effect relationship between long-term mobile phone use or latency and statistically significant increase of ipsilateral head tumour risk, with biological plausibility. Non-blind protocols, which instead are affected by errors, bias, and financial conditioning factors, give negative results with systematic underestimate of such risk. However, also in these studies a statistically significant increase in risk of ipsilateral head tumours is quite common after more than 10 years of mobile phone use or latency. The meta-analyses, our included, examining only data on ipsilateral tumours in subjects using mobile phones since or for at least 10 years, show large and statistically significant increases in risk of ipsilateral brain gliomas and acoustic neuromas. Conclusions Our analysis of the literature studies and of the results from meta-analyses of the significant data alone shows an almost doubling of the risk of head tumours induced by long-term mobile phone use or latency.

2011-01-01

421

Maxillary dentinogenic ghost cell tumour.  

PubMed

Dentinogenic ghost cell tumours are extremely rare, and pose significant diagnostic and therapeutic challenges as this case clearly demonstrates. An awareness of different clinical presentations and distinct histopathological features is important in establishing an early definitive diagnosis and instituting appropriate management. Furthermore, there is little precedent in the literature to guide management in such a case, and we therefore consider this report to be noteworthy and instructive in this respect. PMID:23827283

Biggs, T C; Hayes, S M; Harries, P G; Salib, R J

2013-04-01

422

Mobile phones and head tumours. The discrepancies in cause-effect relationships in the epidemiological studies - how do they arise?  

Microsoft Academic Search

Background  Whether or not there is a relationship between use of mobile phones (analogue and digital cellulars, and cordless) and head\\u000a tumour risk (brain tumours, acoustic neuromas, and salivary gland tumours) is still a matter of debate; progress requires\\u000a a critical analysis of the methodological elements necessary for an impartial evaluation of contradictory studies.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  A close examination of the protocols and

Angelo G Levis; Nadia Minicuci; Paolo Ricci; Valerio Gennaro; Spiridione Garbisa

2011-01-01

423

MRI of a microcystic adnexal carcinoma of the skin mimicking a fibrous tumour: case report and literature review  

PubMed Central

Microcystic adnexal carcinoma of the skin is a very rare malignant tumour arising from the sweat glands. As far as we know, the MRI features of this tumour have not been described in the literature before. In this report we present the MRI features and pathological description of a case of a microcystic adnexal carcinoma in the cheek that was incidentally imaged during brain MRI examination. A review of the relevant literature as well as a discussion of MRI of skin tumours is also presented.

Tawfik, A M; Kreft, A; Wagner, W; Vogl, T J

2011-01-01

424

The application of the movement classification system in the diagnosis of children with Cerebral Palsy  

Microsoft Academic Search

Cerebral Palsy is mean damage to the brain, causing non-progressive brain injury, such as hemiplegia, limbs palsy, epilepsy, involuntary movements, poor coordination. This paper proposes a movement evaluation and classification system, in view Cerebral Palsy children hand movement smoothness evaluation. In addition, the application of the movement classification system in the diagnosis of children with cerebral palsy is also discussed.

Tzyh-Chyang Chang; Jiann-Der Lee; Kai-Wei Wang; Li-Chang Liu; Ching-Yi Wu

2008-01-01

425

Resistance to tumour challenge after tumour laser thermotherapy is associated with a cellular immune response.  

PubMed

Previous studies in our laboratory have shown that interstitial laser thermotherapy (ILT) of an experimental liver tumour is superior to surgical excision, at least partly due to a laser-induced immunological effect. The aim of the present study was to investigate the time-response relationship of the ILT-induced immunisation and the cellular response of macrophages and lymphocytes. A dimethylhydrazine-induced adenocarcinoma was transplanted into the liver of syngeneic rats. Rats with tumour were treated 6-8 days later (tumour size 0.25-0.40 cm(3)) with ILT of tumour or resection of the tumour-bearing lobe. Two groups of rats without tumour were treated with resection of a normal liver lobe or ILT of normal liver. A challenging tumour was implanted into the liver of each rat 2, 5 or 10 weeks after primary treatment. Rats were killed 6, 12 and 48 days (or earlier due to their condition) after challenge (n = 8 in all groups). Immunohistochemical techniques were used to determine lymphocytes (CD8, CD4) and macrophages (ED1, ED2) in rats having had treatment of a primary tumour. Interstitial laser thermotherapy of the first tumour was followed by eradication of challenging tumour and absence of tumour spread. This contrasted with rapid growth and spread of challenging tumour in the other groups. In the challenging vital tumour tissue and in the interface between the tumour and surroundings, the number of ED1 macrophages and CD8 lymphocytes was higher in rats having been treated with the ILT of tumour than in those having undergone resection of the tumour-bearing lobe. The number of ED2 macrophages and CD4 lymphocytes was low and did not vary between these two groups. Interstitial laser thermotherapy elicited an immune response that eradicated a challenging tumour and was associated with increased numbers of tumour-infiltrating macrophages and CD8 lymphocytes. PMID:16091763

Ivarsson, K; Myllymäki, L; Jansner, K; Stenram, U; Tranberg, K-G

2005-08-22

426

Resistance to tumour challenge after tumour laser thermotherapy is associated with a cellular immune response  

PubMed Central

Previous studies in our laboratory have shown that interstitial laser thermotherapy (ILT) of an experimental liver tumour is superior to surgical excision, at least partly due to a laser-induced immunological effect. The aim of the present study was to investigate the time–response relationship of the ILT-induced immunisation and the cellular response of macrophages and lymphocytes. A dimethylhydrazine-induced adenocarcinoma was transplanted into the liver of syngeneic rats. Rats with tumour were treated 6–8 days later (tumour size 0.25–0.40?cm3) with ILT of tumour or resection of the tumour-bearing lobe. Two groups of rats without tumour were treated with resection of a normal liver lobe or ILT of normal liver. A challenging tumour was implanted into the liver of each rat 2, 5 or 10 weeks after primary treatment. Rats were killed 6, 12 and 48 days (or earlier due to their condition) after challenge (n=8 in all groups). Immunohistochemical techniques were used to determine lymphocytes (CD8, CD4) and macrophages (ED1, ED2) in rats having had treatment of a primary tumour. Interstitial laser thermotherapy of the first tumour was followed by eradication of challenging tumour and absence of tumour spread. This contrasted with rapid growth and spread of challenging tumour in the other groups. In the challenging vital tumour tissue and in the interface between the tumour and surroundings, the number of ED1 macrophages and CD8 lymphocytes was higher in rats having been treated with the ILT of tumour than in those having undergone resection of the tumour-bearing lobe. The number of ED2 macrophages and CD4 lymphocytes was low and did not vary between these two groups. Interstitial laser thermotherapy elicited an immune response that eradicated a challenging tumour and was associated with increased numbers of tumour-infiltrating macrophages and CD8 lymphocytes.

Ivarsson, K; Myllymaki, L; Jansner, K; Stenram, U; Tranberg, K-G

2005-01-01

427

Feature selection for the classification of movements from single movement-related potentials  

Microsoft Academic Search

Classification of movement-related potentials recorded from the scalp to their corresponding limb is a crucial task in brain-computer interfaces based on such potentials. Many features can be extracted from raw electroencephalographic signals to be used for classification, but the utilization of irrelevant or superfluous features is detrimental to the performance of classification algorithms. It is, therefore, necessary to select a

Elad Yom-Tov; Gideon F. Inbar

2002-01-01

428

Rare oesophageal tumours: experience of one centre.  

PubMed

AIM OF STUDY: The aim of this study is to compare demographic and clinical data as well as applied treatment methods in patients with rare benign and malignant tumours of the oesophagus. METHODS: Eight hundred and thirty patients with oesophageal cancer were treated in the Department of Surgical Oncology in 1960-2005. In 15 cases (1.8 %), rare benign (n?=?11) or malignant (n?=?4) types of tumours were diagnosed. Patients with rare oesophageal tumours were included in the study, excluding those with squamous cell carcinoma or adenocarcinoma of the oesophagus. Demographic and clinical data were analysed from each patient qualified for the study. Oesophageal X-rays with contrast medium, gastroscopies and, as of 1991, computed tomographies (CTs) were performed as preoperative diagnostic procedures. RESULTS: In the postoperative histopathological examinations, all benign tumours proved to be oesophageal leiomyomas. Four different malignant tumours-a sarcoma, a neuroendocrine carcinoma, a lymphoma, and a squamous cell carcinoma in a patient with Crohn's disease, were diagnosed in the other four patients. In a group of 15 patients with rare oesophageal tumours there were ten (66.7 %) males and five (33.3 %) females. In patients with benign and malignant tumours, the mean age for the benign group reached 44 years (range: 26-75 years old) and 54.7 years (range: 47-59 years old) for the malignant group. In the preoperative period, symptoms such as swallowing disturbances, retrosternal pains, and epigastric pains were observed. Dysphagia was the leading symptom in patients with benign and malignant oesophageal tumours. Out of 15 patients