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Sample records for astrocytic brain tumors

  1. INFLUENCE OF MALIGNIZATIONS LEVEL OF ASTROCYTIC HUMAN BRAIN TUMOR ON THE EXPRESSION OF CONNEXIN-43

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    Grankina A. O.

    2013-11-01

    Full Text Available Study was performed on 12 samples of astrocytic human brain tumors, which differ by the level of malignancy and histological indications. The study was conducted with the method of immunohistochemistry using a commercially available antibody anti-connexin-43 (Cx 43, a prior test of which was carried out on myocardium tissue of rats (positive control. The study showed that with the increasing of malignant level of astrocytomas, there was marked the decreased level of connexin-43 expression of, which is apparently to be associated with the destruction of intercellular gap junctions in tumor tissue

  2. THE ROLE OF GAP JUNCTIONS IN THE DEVELOPMENT OF ASTROCYTIC HUMAN BRAIN TUMOR

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    Grankina A. O.

    2015-01-01

    Full Text Available Recently, much attention is paid to research the role of cell-cell interactions by gap junctions in the process of malignant transformation and mechanisms of antitumor resistance. Meanwhile, the greatest interest is astrocytic tumors. Depending on the degree of malignancy, astrocytomas are divided into: pilocytic astrocytoma (Grade I, subependymal giant cell astrocytoma (Grade I, pleomorphic xanthoastrocytoma (Grade II, diffuse astrocytoma (Grade II, anaplastic astrocytoma (Grade III, glioblastoma (Grade IV gliomatosis cerebri (Grade IV. Information of literature devoted to astrocytic tumors (gliomas - the most common brain tumor in large part obtained in studies in cell cultures and different contradictions. Along with data on the reduction of glial tumors cells communicability through GJ, there is evidence of an opposite character - a functionally active GJ in gliomas and inhibition of tumor growth by reducing intercellular communicability by GJ. However, up to now there have been no studies of the effect and function of hemichannels in cancer cells, which would provide detailed information on: 1 the characteristic of presence and relative abundance of hemichannels in cancer cells; 2 evaluation of absorption / release of hemichannels mediated molecules in tumor cells than in non-tumor cells; 3 functional consequences of activation and blocking of hemichannels in tumor cells and 4 the prognostic value of the expression / activation of hemichannels in human malignancies

  3. Astrocytes Directly Influence Tumor Cell Invasion and Metastasis In Vivo

    OpenAIRE

    Wang, Ling; Cossette, Stephanie M.; Rarick, Kevin R.; Gershan, Jill; Michael B Dwinell; Harder, David R.; Ramchandran, Ramani

    2013-01-01

    Brain metastasis is a defining component of tumor pathophysiology, and the underlying mechanisms responsible for this phenomenon are not well understood. Current dogma is that tumor cells stimulate and activate astrocytes, and this mutual relationship is critical for tumor cell sustenance in the brain. Here, we provide evidence that primary rat neonatal and adult astrocytes secrete factors that proactively induced human lung and breast tumor cell invasion and metastasis capabilities. Among wh...

  4. Astrocytes directly influence tumor cell invasion and metastasis in vivo.

    Directory of Open Access Journals (Sweden)

    Ling Wang

    Full Text Available Brain metastasis is a defining component of tumor pathophysiology, and the underlying mechanisms responsible for this phenomenon are not well understood. Current dogma is that tumor cells stimulate and activate astrocytes, and this mutual relationship is critical for tumor cell sustenance in the brain. Here, we provide evidence that primary rat neonatal and adult astrocytes secrete factors that proactively induced human lung and breast tumor cell invasion and metastasis capabilities. Among which, tumor invasion factors namely matrix metalloprotease-2 (MMP-2 and MMP-9 were partly responsible for the astrocyte media-induced tumor cell invasion. Inhibiting MMPs reduced the ability of tumor cell to migrate and invade in vitro. Further, injection of astrocyte media-conditioned breast cancer cells in mice showed increased invasive activity to the brain and other distant sites. More importantly, blocking the preconditioned tumor cells with broad spectrum MMP inhibitor decreased the invasion and metastasis of the tumor cells, in particular to the brain in vivo. Collectively, our data implicate astrocyte-derived MMP-2 and MMP-9 as critical players that facilitate tumor cell migration and invasion leading to brain metastasis.

  5. Podocalyxin expression in malignant astrocytic tumors

    International Nuclear Information System (INIS)

    Podocalyxin is an anti-adhesive mucin-like transmembrane sialoglycoprotein that has been implicated in the development of aggressive forms of cancer. Podocalyxin is also known as keratan sulfate (KS) proteoglycan. Recently, we revealed that highly sulfated KS or another mucin-like transmembrane sialoglycoprotein podoplanin/aggrus is upregulated in malignant astrocytic tumors. The aim of this study is to examine the relationship between podocalyxin expression and malignant progression of astrocytic tumors. In this study, 51 astrocytic tumors were investigated for podocalyxin expression using immunohistochemistry, Western blot analysis, and quantitative real-time PCR. Immunohistochemistry detected podocalyxin on the surface of tumor cells in six of 14 anaplastic astrocytomas (42.9%) and in 17 of 31 glioblastomas (54.8%), especially around proliferating endothelial cells. In diffuse astrocytoma, podocalyxin expression was observed only in vascular endothelial cells. Podocalyxin might be associated with the malignant progression of astrocytic tumors, and be a useful prognostic marker for astrocytic tumors

  6. Podocalyxin expression in malignant astrocytic tumors.

    Science.gov (United States)

    Hayatsu, Norihito; Kaneko, Mika Kato; Mishima, Kazuhiko; Nishikawa, Ryo; Matsutani, Masao; Price, Janet E; Kato, Yukinari

    2008-09-19

    Podocalyxin is an anti-adhesive mucin-like transmembrane sialoglycoprotein that has been implicated in the development of aggressive forms of cancer. Podocalyxin is also known as keratan sulfate (KS) proteoglycan. Recently, we revealed that highly sulfated KS or another mucin-like transmembrane sialoglycoprotein podoplanin/aggrus is upregulated in malignant astrocytic tumors. The aim of this study is to examine the relationship between podocalyxin expression and malignant progression of astrocytic tumors. In this study, 51 astrocytic tumors were investigated for podocalyxin expression using immunohistochemistry, Western blot analysis, and quantitative real-time PCR. Immunohistochemistry detected podocalyxin on the surface of tumor cells in six of 14 anaplastic astrocytomas (42.9%) and in 17 of 31 glioblastomas (54.8%), especially around proliferating endothelial cells. In diffuse astrocytoma, podocalyxin expression was observed only in vascular endothelial cells. Podocalyxin might be associated with the malignant progression of astrocytic tumors, and be a useful prognostic marker for astrocytic tumors. PMID:18639524

  7. Brain Tumors

    Science.gov (United States)

    A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, or ... cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are metastatic, ...

  8. Brain Tumors

    Science.gov (United States)

    A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, ... cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are ...

  9. Notch Signaling and Brain Tumors

    DEFF Research Database (Denmark)

    Stockhausen, Marie; Kristoffersen, Karina; Poulsen, Hans Skovgaard

    2011-01-01

    Human brain tumors are a heterogenous group of neoplasms occurring inside the cranium and the central spinal cord. In adults and children, astrocytic glioma and medulloblastoma are the most common subtypes of primary brain tumors. These tumor types are thought to arise from cells in which Notch...

  10. Pyk2 is essential for astrocytes mobility following brain lesion.

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    Giralt, Albert; Coura, Renata; Girault, Jean-Antoine

    2016-04-01

    Proline-rich tyrosine kinase 2 (Pyk2) is a calcium-dependent, non-receptor protein-tyrosine kinase of the focal adhesion kinase (FAK) family. Pyk2 is enriched in the brain, especially the forebrain. Pyk2 is highly expressed in neurons but is also present in astrocytes, where its role is not known. We used Pyk2 knockout mice (Pyk2(-/-) ) developed in our laboratory to investigate the function of Pyk2 in astrocytes. Morphology and basic properties of astrocytes in vivo and in culture were not altered in the absence of Pyk2. However, following stab lesions in the motor cortex, astrocytes-mediated wound filling was slower in Pyk2(-/-) than in wild-type littermates. In an in vitro wound healing model, Pyk2(-/-) astrocytes migrated slower than Pyk2(+/+) astrocytes. The role of Pyk2 in actin dynamics was investigated by treating astrocytic cultures with the actin-depolymerizing drug latrunculin B. Actin filaments re-polymerization after latrunculin B treatment was delayed in Pyk2(-/-) astrocytes as compared with wild-type astrocytes. We mimicked wound-induced activation by treating astrocytes in culture with tumor-necrosis factor alpha (TNFα), which increased Pyk2 phosphorylation at Tyr402. TNFα increased PKC activity, and Rac1 phosphorylation at Ser71 similarly in wild-type and Pyk2-deficient astrocytes. Conversely, we found that gelsolin, an actin-capping protein known to interact with Pyk2 in other cell types, was less enriched at the leading edge of migrating Pyk2(-/-) astrocytes, suggesting that its lack of recruitment mediated in part the effects of the mutation. This work shows the critical role of Pyk2 in astrocytes migration during wound healing. GLIA 2016;64:620-634. PMID:26663135

  11. p53 protein alterations in adult astrocytic tumors and oligodendrogliomas

    Directory of Open Access Journals (Sweden)

    Nayak Anupma

    2004-04-01

    Full Text Available BACKGROUND: p53 is a tumor suppressor gene implicated in the genesis of a variety of malignancies including brain tumors. Overexpression of the p53 protein is often used as a surrogate indicator of alterations in the p53 gene. AIMS: In this study, data is presented on p53 protein expression in adult cases (>15 years of age of astrocytic (n=152 and oligodendroglial (n=28 tumors of all grades. Of the astrocytic tumors, 86% were supratentorial in location while remaining 14% were located infratentorially - 8 in the the cerebellum and 13 in the brainstem. All the oligodendrogliomas were supratentorial. MATERIALS AND METHODS: p53 protein expression was evaluated on formalin-fixed paraffin-embedded sections using streptavidin biotin immunoperoxidase technique after high temperature antigen retrieval. RESULTS: Overall 52% of supratentorial astrocytic tumors showed p53 immunopositivity with no correlation to the histological grade. Thus, 58.8% of diffuse astrocytomas (WHO Grade II, 53.8% of anaplastic astrocytomas (WHO Grade III and 50% of glioblastomas (WHO Grade IV were p53 protein positive. In contrast, all the infratentorial tumors were p53 negative except for one brainstem glioblastoma. Similarly, pilocytic astrocytomas were uniformly p53 negative irrespective of the location. Among oligodendroglial tumors, the overall frequency of p53 immunopositivity was lower (only 28%, though a trend of positive correlation with the tumor grade was noted - 25% in Grade II and 31.5% in grade III (anaplastic oligodendroglioma. Interestingly, p53 labeling index (p53 LI did not correlate with the histopathological grade in both astrocytic and oligodendroglial tumors. CONCLUSIONS: Thus, this study gives an insight into the genetic and hence biological heterogeneity of gliomas, not only between astrocytic tumors vs. oligodendrogliomas but also within astrocytic tumors with regard to their grade and location. With p53 gene therapy trials in progress, this will

  12. Stargazing: Monitoring subcellular dynamics of brain astrocytes.

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    Benjamin Kacerovsky, J; Murai, K K

    2016-05-26

    Astrocytes are major non-neuronal cell types in the central nervous system that regulate a variety of processes in the brain including synaptic transmission, neurometabolism, and cerebrovasculature tone. Recent discoveries have revealed that astrocytes perform very specialized and heterogeneous roles in brain homeostasis and function. Exactly how astrocytes fulfill such diverse roles in the brain remains to be fully understood and is an active area of research. In this review, we focus on the complex subcellular anatomical features of protoplasmic gray matter astrocytes in the mature, healthy brain that likely empower these cells with the ability to detect and respond to changes in neuronal and synaptic activity. In particular, we discuss how intricate processes on astrocytes allow these cells to communicate with neurons and their synapses and strategically deliver specific cellular organelles such as mitochondria and ribosomes to active compartments within the neuropil. Understanding the properties of these structural elements will lead to a better understanding of how astrocytes function in the healthy and diseased brain. PMID:26162237

  13. Risk factors for astrocytic glioma and primitive neuroectodermal tumor of the brain in young children: a report from the Children's Cancer Group.

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    Bunin, G R; Buckley, J D; Boesel, C P; Rorke, L B; Meadows, A T

    1994-01-01

    We conducted a matched case-control study to investigate risk factors for the two most common types of brain tumors in children, astrocytic glioma and primitive neuroectodermal tumor (PNET). Since the study focused on gestational exposures, we restricted it to young children because these exposures would be expected to act early in life. Parents of 155 astrocytic glioma cases, 166 PNET cases, and controls identified by random digit dialing completed telephone interviews. Few associations occurred with the hypothesized risk factors, which were gestational exposure to alcohol, hair coloring products, farms, and substances containing N-nitroso compounds (passive smoking, makeup, incense, new cars, pacifiers, baby bottles, beer). Of the products studied that contain N-nitroso compounds, only beer was associated with a significantly increased risk of either tumor type [odds ratio (OR) for PNET = 4.0; 95% confidence interval (CI), 1.1-22.1; P = 0.04]. Elevated ORs for PNET were observed for farm residence of the mother during the pregnancy (OR = 3.7; 95% CI, 0.8-23.9; P = 0.06) and of the child for at least a year (OR = 5.0; 95% CI, 1.1-46.8; P = 0.04). Significant associations with astrocytoma were observed for mother's use of kerosene (OR = 8.9; 95% CI, 1.1-71.1; P = 0.04) and birth by Caesarean section (OR = 1.8; 95% CI, 1.1-3.2; P = 0.03). History of miscarriage was associated with a lower risk of PNET (OR = 0.5; 95% CI, 0.3-0.9; P = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8019366

  14. Brain tumor

    International Nuclear Information System (INIS)

    BNCT in the past was not widely accepted because of poor usability of a nuclear reactor as a neutron source. Recently, technical advancements in the accelerator field have made accelerator-based BNCT feasible. Consequently, clinical trials of intractable brain tumors have started using it since 2012. In this review, our clinical results obtained from conventional reactor-based BNCT for treatment of brain tumors are introduced. It is strong hope that accelerator-based BNCT becomes a standard therapy for current intractable brain tumors. (author)

  15. Astrocytes.

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    Kimelberg, Harold K.; Norenberg, Michael D.

    1989-01-01

    Describes the astrocytes' function as equal partners with neurons in both the normal and the abnormal brain. Discusses the developmental scaffolds, inert scar tissue, Huntington's disease, psychiatric disorders, and the identification of these brain cells. (RT)

  16. Common astrocytic programs during brain development, injury and cancer

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    Silver, Daniel J.; Steindler, Dennis A.

    2009-01-01

    In addition to radial glial cells of neurohistogenesis, immature astrocytes with stem-cell-like properties cordon off emerging functional patterns in the developing brain. Astrocytes also can be stem cells during adult neurogenesis, and a proposed potency of injury-associated reactive astrocytes has recently been substantiated. Astrocytic cells might additionally be involved in cancer stem cell-associated gliomagenesis. Thus, there are distinguishing roles for stem-cell-like astrocytes during...

  17. Brain tumor - primary - adults

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    ... Vestibular schwannoma (acoustic neuroma) - adults; Meningioma - adults; Cancer - brain tumor (adults) ... Primary brain tumors include any tumor that starts in the brain. Primary brain tumors can start from brain cells, ...

  18. Calcium wave of Brain Astrocytes

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    Cornell Bell, A. H.

    1997-03-01

    Time lapse confocal scanning laser microscopy was used to study hippocampal astrocyte cultures loaded with a calcium indicator, Fluo3-AM (4 uM). kThe neurotransmitter kainate (100uM) overwhelms the Na+-buffering capacity of astrocytes within 100 sec resulting in reversal of the Na+/Ca2+ exchanger. This results in a subcellular site where Ca2+ entering the cytoplasm contributes to a long-distance Ca2+ wave which travels at 20 um/sec without decrement. Image analysis has shown calcium waves not only at a high Kainate dose, but also at a low Kainate dose, e.g. 10uM. These are, however, shortlived and burried in an extremely noisy background and only detectable by analyzing the calcium waves images for spatio-temporal coherence. As the kainate dose increases, more large scale coherent structures with visible geometric features (spiral waves and target waves) can be observed. Multiple spiral waves are produced when the Kainate dose increases to 100 uM. These waves travel at a constant velocity across entire microscope fields for long time periods (>30 mins). Na+ channels have no effect on the Kainate wave. Voltage-gated Ca2+ channels are not involved and Ca2+ enters through reversal of the exchanger. Ca2+ release from stores does not contribute to the kainate wave. Removal of Na+ or Ca2+ from outside and the specific Na+/Ca2+ exchange inhibitor benzamil (10 uM) inhibit the kainate wave. A functional antibody to alpha6-Integrin which is localized to membrane regions between cells inhibits the spread of the kainate wave in a dose and time-dependent manner. Fluorescence Recovery after Photobleach (FRAP) techniques indicate that gap junctions remain open between cells. This would imply that Ca2+ or IP3 need not pass through the gap junction, but reversal of the exchanger would propel the Ca2+ wave at the cell surface.

  19. Tumor Microenvironment in the Brain

    International Nuclear Information System (INIS)

    In addition to malignant cancer cells, tumors contain a variety of different stromal cells that constitute the tumor microenvironment. Some of these cell types provide crucial support for tumor growth, while others have been suggested to actually inhibit tumor progression. The composition of tumor microenvironment varies depending on the tumor site. The brain in particular consists of numerous specialized cell types such as microglia, astrocytes, and brain endothelial cells. In addition to these brain-resident cells, primary and metastatic brain tumors have also been shown to be infiltrated by different populations of bone marrow-derived cells. The role of different cell types that constitute tumor microenvironment in the progression of brain malignancies is only poorly understood. Tumor microenvironment has been shown to be a promising therapeutic target and diagnostic marker in extracranial malignancies. A better understanding of tumor microenvironment in the brain would therefore be expected to contribute to the development of improved therapies for brain tumors that are urgently required due to a poor availability of treatments for these malignancies. This review summarizes some of the known interactions between brain tumors and different stromal cells, and also discusses potential therapeutic approaches within this context

  20. Tumor Microenvironment in the Brain

    Energy Technology Data Exchange (ETDEWEB)

    Lorger, Mihaela [Leeds Institute of Molecular Medicine, University of Leeds, St. James’s University Hospital, Beckett Street, Leeds, LS9 7TF (United Kingdom)

    2012-02-22

    In addition to malignant cancer cells, tumors contain a variety of different stromal cells that constitute the tumor microenvironment. Some of these cell types provide crucial support for tumor growth, while others have been suggested to actually inhibit tumor progression. The composition of tumor microenvironment varies depending on the tumor site. The brain in particular consists of numerous specialized cell types such as microglia, astrocytes, and brain endothelial cells. In addition to these brain-resident cells, primary and metastatic brain tumors have also been shown to be infiltrated by different populations of bone marrow-derived cells. The role of different cell types that constitute tumor microenvironment in the progression of brain malignancies is only poorly understood. Tumor microenvironment has been shown to be a promising therapeutic target and diagnostic marker in extracranial malignancies. A better understanding of tumor microenvironment in the brain would therefore be expected to contribute to the development of improved therapies for brain tumors that are urgently required due to a poor availability of treatments for these malignancies. This review summarizes some of the known interactions between brain tumors and different stromal cells, and also discusses potential therapeutic approaches within this context.

  1. Brain tumor - children

    Science.gov (United States)

    ... children; Neuroglioma - children; Oligodendroglioma - children; Meningioma - children; Cancer - brain tumor (children) ... The cause of primary brain tumors is unknown. Primary brain tumors may ... (spread to nearby areas) Cancerous (malignant) Brain tumors ...

  2. Metabolic dysfunction in the brain: implications of astrocyte activation

    OpenAIRE

    Sonia Luz Albarracin

    2015-01-01

    Astrocytes are the most abundant cells in the central nervous system (CNS). They participate in different processes such as maintaining the blood–brain barrier and ion homeostasis, uptake and turnover of neurotransmitters, and formation of synapses. In addition, astrocytes also respond to brain insults to prevent the damage. For instance, astrocyte activation plays a central role in the cellular response to brain insults like trauma, infections, stroke, tumorigenesis, and neurodegeneration....

  3. Astrocytes mediate the neuroprotective effects of Tibolone following brain injury

    OpenAIRE

    Luis Miguel Garcia-Segura; Barreto, George E.

    2015-01-01

    Recently, astrocytes have become a key central player in mediating important functions in the brain. These physiological processes include neurotransmitter recycling, energy management, metabolic shuttle, immune sensing, K+ buffer, antioxidant supply and release of neurotrophic factors and gliotransmitters. These astrocytic roles are somehow altered upon brain injury, therefore strategies aimed at better protecting astrocytes are an essential asset to maintain brain homeostasis. In this cont...

  4. American Brain Tumor Association

    Science.gov (United States)

    ... For Health Care Professionals About Us Our Founders Board of Directors Staff Leadership Strategic Plan Financials News Careers Brain Tumor Information Brain Anatomy Brain Tumor Symptoms Diagnosis Types of Tumors Tumor Grade Risk Factors Brain Tumor Statistics ABTA Publications Brain Tumor ...

  5. Brain Tumor Surgery

    Science.gov (United States)

    ... Pediatric Caregiver Resource Center About Us Our Founders Board of Directors Staff Leadership Strategic Plan Financials News Careers Brain Tumor Information Brain Anatomy Brain Tumor Symptoms Diagnosis Types of Tumors Tumor Grade Risk Factors Brain Tumor Statistics ABTA Publications Brain Tumor ...

  6. Brain Tumors (For Parents)

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    ... Story" 5 Things to Know About Zika & Pregnancy Brain Tumors KidsHealth > For Parents > Brain Tumors Print A ... radiation therapy or chemotherapy, or both. Types of Brain Tumors There are many different types of brain ...

  7. Brain tumor (image)

    Science.gov (United States)

    Brain tumors are classified depending on the exact site of the tumor, the type of tissue involved, benign ... tendencies of the tumor, and other factors. Primary brain tumors can arise from the brain cells, the meninges ( ...

  8. Astrocyte heterogeneity in the brain: from development to disease

    Directory of Open Access Journals (Sweden)

    Marcos R Costa

    2015-03-01

    Full Text Available In the last decades, astrocytes have risen from passive supporters of neuronal activity to central players in brain function and cognition. Likewise, the heterogeneity of astrocytes starts to become recognized in contrast to the homogeneous population previously predicted. In this review, we focused on astrocyte heterogeneity in terms of their morphological, protein expression and functional aspects and debate in a historical perspective the diversity encountered in glial progenitors and how they may reflect mature astrocyte heterogeneity. We discussed data that show that different progenitors may have unsuspected roles in developmental processes. We have approached the functions of astrocyte subpopulations on the onset of psychiatric and neurological diseases.

  9. Adolescent and Pediatric Brain Tumors

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    ... abta.org Donate Now Menu Adolescent & Pediatric Brain Tumors Brain Tumors In Children Pediatric Brain Tumor Diagnosis Family ... or Complete our contact form Adolescent & Pediatric Brain Tumors Brain Tumors In Children Pediatric Brain Tumor Diagnosis Family ...

  10. Brain Tumor Diagnosis

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    ... Tumors Tumor Grading and Staging Types of Tumors Risk Factors Brain Tumor Statistics Webinars Anytime Learning About Us Our Founders Board of Directors Staff Leadership Strategic Plan Financials News Careers Brain ...

  11. Astrocytes and diffusive spread of substances in brain extracellular space

    OpenAIRE

    Sherpa, Ang D.; Hrabetova, Sabina

    2016-01-01

    Brain function is based on communication between individual cells, neurons and glia. From a traditional point of view, neurons play a central role in the fast transfer of information in the central nervous system while astrocytes, major type of glia, serve as housekeeping elements maintaining homeostasis of the extracellular microenvironment. This view has dramatically changed in recent years as many findings ascribe new roles to astrocytes. It is becoming evident that astrocytes communica...

  12. Astrocyte heterogeneity in the brain: from development to disease

    OpenAIRE

    Costa, Marcos R.; Cecilia Hedin-Pereira

    2015-01-01

    In the last decades, astrocytes have risen from passive supporters of neuronal activity to central players in brain function and cognition. Likewise, the heterogeneity of astrocytes starts to become recognized in contrast to the homogeneous population previously predicted. In this review, we focused on astrocyte heterogeneity in terms of their morphological, protein expression and functional aspects, and debate in a historical perspective the diversity encountered in glial progenitors and how...

  13. Astrocytes as therapeutic targets of estrogenic compounds following brain injuries

    Directory of Open Access Journals (Sweden)

    George E. Barreto

    2015-03-01

    Full Text Available For decades, astrocytes have been considered to be non-excitable support cells that are relatively resistant to brain injury. This view has changed radically during the past twenty years. Multiple essential functions are performed by astrocytes in normal brain. Astrocytes are dynamically involved in synaptic transmission, metabolic and ionic homeostasis, and inflammatory maintenance of the blood brain barrier. Advances in our understanding of astrocytes include new observations about their structure, organization, and function. Astrocytes play an active and important role in the pathophysiology of brain damage. Brain injury impairs mitochondrial function and this is accompanied by increased oxidative stress, leading to prominent astrogliosis, which involves changes in gene expression and morphology, and therefore glial scar formation. Recent works have demonstrated a protective role of reactive astrocytes after brain injury. Nevertheless, others have pointed to an inhibitory role of astrocytes in axonal regeneration after injury. Reactive astrogliosis is a complex phenomenon that includes a mixture of positive and negative responses for neuronal survival and regeneration. Reactive astroglia maintains the integrity of the blood-brain barrier and the survival of the perilesional tissue, but may prevent axonal and damaged tissue regeneration. Neuroprotective strategies aiming at reducing gliosis and enhance brain plasticity are of potential interest for translational neuroscience research in brain injuries. In this context, neurosteroids have shown to be a promising strategy to protect brain against injury, as their effects may rely on reducing gliosis, brain inflammation and potentially modulating recovery from brain injury by engaging mechanisms of neural plasticity. In conclusion, in this work we will consider particularly the two-edged sword role of reactive astrocytes, which is an experimental paradigm helpful in discriminating destructive

  14. Pediatric brain tumors of neuroepithelial tissue

    International Nuclear Information System (INIS)

    Tumors of neuroepithelial tissue represent the largest group of pediatric brain tumors by far and has therefore been divided into several discrete tumor subtypes each corresponding to a specific component of the neuropil. The neuropil contains several subtypes of glial cells, including astrocytes, oligodendrocytes, ependymal cells and modified ependymal cells that form the choroid plexus. This review discusses the imaging aspects of the most common pediatric tumors of neuroepithelial tissue. (orig.)

  15. Contributions of Glycogen to Astrocytic Energetics during Brain Activation

    OpenAIRE

    Dienel, Gerald A.; Nancy F Cruz

    2014-01-01

    Glycogen is the major store of glucose in brain and is mainly in astrocytes. Brain glycogen levels in unstimulated, carefully-handled rats are 10-12 mol/g, and assuming that astrocytes account for half the brain mass, astrocytic glycogen content is twice as high. Glycogen turnover is slow under basal conditions, but it is mobilized during activation. There is no net increase in incorporation of label from glucose during activation, whereas label release from pre-labeled glycogen exceeds net g...

  16. Brain tumor - primary - adults

    Science.gov (United States)

    ... Vestibular schwannoma (acoustic neuroma) - adults; Meningioma - adults; Cancer - brain tumor (adults) ... wireless devices Head injuries Smoking Hormone therapy SPECIFIC TUMOR TYPES Brain tumors are classified depending on: Location of the ...

  17. Childhood Brain Tumors

    Science.gov (United States)

    Brain tumors are abnormal growths inside the skull. They are among the most common types of childhood ... still be serious. Malignant tumors are cancerous. Childhood brain and spinal cord tumors can cause headaches and ...

  18. Selenoprotein S expression in reactive astrocytes following brain injury.

    Science.gov (United States)

    Fradejas, Noelia; Serrano-Pérez, Maria Del Carmen; Tranque, Pedro; Calvo, Soledad

    2011-06-01

    Selenoprotein S (SelS) is an endoplasmic reticulum (ER)-resident protein involved in the unfolded protein response. Besides reducing ER-stress, SelS attenuates inflammation by decreasing pro-inflammatory cytokines. We have recently shown that SelS is responsive to ischemia in cultured astrocytes. To check the possible association of SelS with astrocyte activation, here we investigate the expression of SelS in two models of brain injury: kainic acid (KA) induced excitotoxicity and cortical mechanical lesion. The regulation of SelS and its functional consequences for neuroinflammation, ER-stress, and cell survival were further analyzed using cultured astrocytes from mouse and human. According to our immunofluorescence analysis, SelS expression is prominent in neurons and hardly detectable in astrocytes from control mice. However, brain injury intensely upregulates SelS, specifically in reactive astrocytes. SelS induction by KA was evident at 12 h and faded out after reaching maximum levels at 3-4 days. Analysis of mRNA and protein expression in cultured astrocytes showed SelS upregulation by inflammatory stimuli as well as ER-stress inducers. In turn, siRNA-mediated SelS silencing combined with adenoviral overexpression assays demonstrated that SelS reduces ER-stress markers CHOP and spliced XBP-1, as well as inflammatory cytokines IL-1β and IL-6 in stimulated astrocytes. SelS overexpression increased astrocyte resistance to ER-stress and inflammatory stimuli. Conversely, SelS suppression compromised astrocyte viability. In summary, our results reveal the upregulation of SelS expression in reactive astrocytes, as well as a new protective role for SelS against inflammation and ER-stress that can be relevant to astrocyte function in the context of inflammatory neuropathologies. PMID:21456042

  19. Pediatric brain tumors

    International Nuclear Information System (INIS)

    Among all causes of death in children from solid tumors, pediatric brain tumors are the most common. This article includes an overview of a subset of infratentorial and supratentorial tumors with a focus on tumor imaging features and molecular advances and treatments of these tumors. Key to understanding the imaging features of brain tumors is a firm grasp of other disease processes that can mimic tumor on imaging. We also review imaging features of a common subset of tumor mimics. (orig.)

  20. Pediatric brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Poussaint, Tina Y. [Department of Radiology, Boston, MA (United States); Panigrahy, Ashok [Children' s Hospital of Pittsburgh of University of Pittsburgh Medical Center, Department of Radiology, Pittsburgh, PA (United States); Huisman, Thierry A.G.M. [Charlotte R. Bloomberg Children' s Center, Johns Hopkins Hospital, Division of Pediatric Radiology and Pediatric Neuroradiology, Baltimore, MD (United States)

    2015-09-15

    Among all causes of death in children from solid tumors, pediatric brain tumors are the most common. This article includes an overview of a subset of infratentorial and supratentorial tumors with a focus on tumor imaging features and molecular advances and treatments of these tumors. Key to understanding the imaging features of brain tumors is a firm grasp of other disease processes that can mimic tumor on imaging. We also review imaging features of a common subset of tumor mimics. (orig.)

  1. Brain tumors

    International Nuclear Information System (INIS)

    Magnetic Resonance Tomography (MRT) is the method of choice for the diagnostics of cerebral gliomas, but the differentiation of tumour tissue from unspecific tissue changes is limited. Positron emission tomography (PET) and Single-Photon-Emission-Computed Tomography (SPECT) may offer relevant additional information which allows for a more accurate diagnostics in unclear situations. Especially, radiolabeled amino acids offer a better delineation of cerebral gliomas which allows an improved guidance of biopsy, planning of surgery and radiation therapy. Furthermore, amino acid imaging appears to be useful to differentiate tumor recurrence from unspecific posttherapeutic tissue, to predict the prognosis especially in low grade gliomas and to monitor the metabolic response during tumor therapy. (orig.)

  2. Pyk2 is essential for astrocytes mobility following brain lesion

    OpenAIRE

    Giralt, Albert; Coura, Renata; Girault, Jean-Antoine

    2016-01-01

    Proline-rich tyrosine kinase 2 (Pyk2) is a calcium-dependent, non-receptor protein-tyrosine kinase of the focal adhesion kinase (FAK) family. Pyk2 is enriched in the brain, especially the forebrain. Pyk2 is highly expressed in neurons but is also present in astrocytes, where its role is not known. We used Pyk2 knockout mice (Pyk2−/−) developed in our laboratory to investigate the function of Pyk2 in astrocytes. Morphology and basic properties of astrocytes in vivo and in culture were not alte...

  3. Pediatric Brain Tumor Foundation

    Science.gov (United States)

    ... you insights into your child's treatment. LEARN MORE Brain tumors and their treatment can be deadly so ... Michigan event celebrates 25 years Read more >> Pediatric Brain Tumor Foundation 302 Ridgefield Court, Asheville, NC 28806 ...

  4. Astrocytes mediate the neuroprotective effects of Tibolone following brain injury

    Directory of Open Access Journals (Sweden)

    Luis Miguel Garcia-Segura

    2015-04-01

    Full Text Available Recently, astrocytes have become a key central player in mediating important functions in the brain. These physiological processes include neurotransmitter recycling, energy management, metabolic shuttle, immune sensing, K+ buffer, antioxidant supply and release of neurotrophic factors and gliotransmitters. These astrocytic roles are somehow altered upon brain injury, therefore strategies aimed at better protecting astrocytes are an essential asset to maintain brain homeostasis. In this context, estrogenic compounds, such as Tibolone, have attracted attention for their beneficial effects in acute and chronic degenerative diseases. Tibolone may act through binding to estrogen, androgen or progesterone receptors and exert protective effects by reducing astrocytes cell death and oxidative stress signaling mechanisms. Although Tibolone has a multifactorial effect in the brain, its mechanisms of action are not completely understood. In this work, we highlight the role of Tibolone in brain protection upon damage, how astrocytes might mediate part of its neuroprotective actions and discuss the effects of Tibolone in diminishing the harmful consequences of a metabolic insult and energy failure in the setting of a pathological event.

  5. Brain and Spinal Tumors

    Science.gov (United States)

    ... Awards Enhancing Diversity Find People About NINDS NINDS Brain and Spinal Tumors Information Page Synonym(s): Spinal Cord ... en Español Additional resources from MedlinePlus What are Brain and Spinal Tumors? Tumors of the brain and ...

  6. Childhood Brain Tumors

    Science.gov (United States)

    ... They are among the most common types of childhood cancers. Some are benign tumors, which aren't ... can still be serious. Malignant tumors are cancerous. Childhood brain and spinal cord tumors can cause headaches ...

  7. Accumulation of silver nanoparticles by cultured primary brain astrocytes

    Science.gov (United States)

    Luther, Eva M.; Koehler, Yvonne; Diendorf, Joerg; Epple, Matthias; Dringen, Ralf

    2011-09-01

    Silver nanoparticles (AgNP) are components of various food industry products and are frequently used for medical equipment and materials. Although such particles enter the vertebrate brain, little is known on their biocompatibility for brain cells. To study the consequences of an AgNP exposure of brain cells we have treated astrocyte-rich primary cultures with polyvinylpyrrolidone (PVP)-coated AgNP. The incubation of cultured astrocytes with micromolar concentrations of AgNP for up to 24 h resulted in a time- and concentration-dependent accumulation of silver, but did not compromise the cell viability nor lower the cellular glutathione content. In contrast, the incubation of astrocytes for 4 h with identical amounts of silver as AgNO3 already severely compromised the cell viability and completely deprived the cells of glutathione. The accumulation of AgNP by astrocytes was proportional to the concentration of AgNP applied and significantly lowered by about 30% in the presence of the endocytosis inhibitors chloroquine or amiloride. Incubation at 4 °C reduced the accumulation of AgNP by 80% compared to the values obtained for cells that had been exposed to AgNP at 37 °C. These data demonstrate that viable cultured brain astrocytes efficiently accumulate PVP-coated AgNP in a temperature-dependent process that most likely involves endocytotic pathways.

  8. Accumulation of silver nanoparticles by cultured primary brain astrocytes

    International Nuclear Information System (INIS)

    Silver nanoparticles (AgNP) are components of various food industry products and are frequently used for medical equipment and materials. Although such particles enter the vertebrate brain, little is known on their biocompatibility for brain cells. To study the consequences of an AgNP exposure of brain cells we have treated astrocyte-rich primary cultures with polyvinylpyrrolidone (PVP)-coated AgNP. The incubation of cultured astrocytes with micromolar concentrations of AgNP for up to 24 h resulted in a time- and concentration-dependent accumulation of silver, but did not compromise the cell viability nor lower the cellular glutathione content. In contrast, the incubation of astrocytes for 4 h with identical amounts of silver as AgNO3 already severely compromised the cell viability and completely deprived the cells of glutathione. The accumulation of AgNP by astrocytes was proportional to the concentration of AgNP applied and significantly lowered by about 30% in the presence of the endocytosis inhibitors chloroquine or amiloride. Incubation at 4 0C reduced the accumulation of AgNP by 80% compared to the values obtained for cells that had been exposed to AgNP at 37 0C. These data demonstrate that viable cultured brain astrocytes efficiently accumulate PVP-coated AgNP in a temperature-dependent process that most likely involves endocytotic pathways.

  9. Accumulation of silver nanoparticles by cultured primary brain astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Luther, Eva M; Koehler, Yvonne; Dringen, Ralf [Center for Biomolecular Interactions Bremen, University of Bremen, PO Box 330440, D-28334 Bremen (Germany); Diendorf, Joerg; Epple, Matthias, E-mail: ralf.dringen@uni-bremen.de [Inorganic Chemistry and Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Universitaetsstrasse 5-7, D-45117 Essen (Germany)

    2011-09-16

    Silver nanoparticles (AgNP) are components of various food industry products and are frequently used for medical equipment and materials. Although such particles enter the vertebrate brain, little is known on their biocompatibility for brain cells. To study the consequences of an AgNP exposure of brain cells we have treated astrocyte-rich primary cultures with polyvinylpyrrolidone (PVP)-coated AgNP. The incubation of cultured astrocytes with micromolar concentrations of AgNP for up to 24 h resulted in a time- and concentration-dependent accumulation of silver, but did not compromise the cell viability nor lower the cellular glutathione content. In contrast, the incubation of astrocytes for 4 h with identical amounts of silver as AgNO{sub 3} already severely compromised the cell viability and completely deprived the cells of glutathione. The accumulation of AgNP by astrocytes was proportional to the concentration of AgNP applied and significantly lowered by about 30% in the presence of the endocytosis inhibitors chloroquine or amiloride. Incubation at 4 {sup 0}C reduced the accumulation of AgNP by 80% compared to the values obtained for cells that had been exposed to AgNP at 37 {sup 0}C. These data demonstrate that viable cultured brain astrocytes efficiently accumulate PVP-coated AgNP in a temperature-dependent process that most likely involves endocytotic pathways.

  10. Astrocytes Upregulate Survival Genes in Tumor Cells and Induce Protection from Chemotherapy

    Directory of Open Access Journals (Sweden)

    Sun-Jin Kim

    2011-03-01

    Full Text Available In the United States, more than 40% of cancer patients develop brain metastasis. The median survival for untreated patients is 1 to 2 months, which may be extended to 6 months with conventional radiotherapy and chemotherapy. The growth and survival of metastasis depend on the interaction of tumor cells with host factors in the organ microenvironment. Brain metastases are surrounded and infiltrated by activated astrocytes and are highly resistant to chemotherapy. We report here that coculture of human breast cancer cells or lung cancer cells with murine astrocytes (but not murine fibroblasts led to the up-regulation of survival genes, including GSTA5, BCL2L1, and TWIST1, in the tumor cells. The degree of up-regulation directly correlated with increased resistance to all tested chemotherapeutic agents. We further show that the up-regulation of the survival genes and consequent resistance are dependent on the direct contact between the astrocytes and tumor cells through gap junctions and are therefore transient. Knocking down these genes with specific small interfering RNA rendered the tumor cells sensitive to chemotherapeutic agents. These data clearly demonstrate that host cells in the microenvironment influence the biologic behavior of tumor cells and reinforce the contention that the organ microenvironment must be taken into consideration during the design of therapy.

  11. Studies on astrocyte function : potential roles in brain water homeostasis and neuroprotection

    OpenAIRE

    Song, Yutong

    2012-01-01

    Astrocytes are essential in brain homeostasis and function, including maintenance of water and ion balance. Astrocytes express the water channel aquaporin 4 (AQP4), implicated in both physiological functions and injury processes associated with brain edema, a common consequence of brain diseases. As part of the tripartite synapse astrocytes are tightly coupled to normal brain function via neuron-astrocyte interactions and by providing metabolic support to neurons as well as con...

  12. Activation of NF-κB mediates astrocyte swelling and brain edema in traumatic brain injury.

    Science.gov (United States)

    Jayakumar, Arumugam R; Tong, Xiao Y; Ruiz-Cordero, Roberto; Bregy, Amade; Bethea, John R; Bramlett, Helen M; Norenberg, Michael D

    2014-07-15

    Brain edema and associated increased intracranial pressure are major consequences of traumatic brain injury (TBI). While astrocyte swelling (cytotoxic edema) represents a major component of the brain edema in the early phase of TBI, its mechanisms are unclear. One factor known to be activated by trauma is nuclear factor-κB (NF-κB). Because this factor has been implicated in the mechanism of cell swelling/brain edema in other neurological conditions, we examined whether NF-κB might also be involved in the mediation of post-traumatic astrocyte swelling/brain edema. Here we show an increase in NF-κB activation in cultured astrocytes at 1 and 3 h after trauma (fluid percussion injury, FPI), and that BAY 11-7082, an inhibitor of NF-κB, significantly blocked the trauma-induced astrocyte swelling. Increased activities of nicotinamide adenine dinucleotide phosphate-oxidase and the Na(+), K(+), 2Cl(-) cotransporter were also observed in cultured astrocytes after trauma, and BAY 11-7082 reduced these effects. We also examined the role of NF-κB in the mechanism of cell swelling by using astrocyte cultures derived from transgenic (Tg) mice with a functional inactivation of astrocytic NF-κB. Exposure of cultured astrocytes from wild-type mice to in vitro trauma (3 h) caused a significant increase in cell swelling. By contrast, traumatized astrocyte cultures derived from NF-κB Tg mice showed no swelling. We also found increased astrocytic NF-κB activation and brain water content in rats after FPI, while BAY 11-7082 significantly reduced such effects. Our findings strongly suggest that activation of astrocytic NF-κB represents a key element in the process by which cytotoxic brain edema occurs after TBI. PMID:24471369

  13. Transport of 3-hydroxybutyrate by cultured rat brain astrocytes

    International Nuclear Information System (INIS)

    Studies by a number of investigators have shown that 3-hydroxybutyrate is a preferred energy substrate for brain during early development. Since recent studies by the authors group suggest that the utilization of oxidizable substrates by brain may be regulated in part by transport across the plasma membrane, the authors investigated the transport of [3H] D- and L-3-hydroxybutyrate and 3-hydroxy-[3-14C] butyrate by primary cultures of rat brain astrocytes. The data is consistent with the hypothesis that 3-hydroxybutyrate is taken up into cultured rat brain astrocytes by both diffusion and a carrier mediated transport system, and further support the concept that transport at the cellular level contributes to the regulation of substrate utilization by brain cells

  14. Pazopanib Inhibits the Activation of PDGFRβ-Expressing Astrocytes in the Brain Metastatic Microenvironment of Breast Cancer Cells

    OpenAIRE

    Gril, Brunilde; Palmieri, Diane; Qian, Yongzhen; Anwar, Talha; Liewehr, David J.; Steinberg, Seth M.; Andreu, Zoraida; Masana, Daniel; Fernández, Paloma; Steeg, Patricia S; Vidal-Vanaclocha, Fernando

    2013-01-01

    Brain metastases occur in more than one-third of metastatic breast cancer patients whose tumors overexpress HER2 or are triple negative. Brain colonization of cancer cells occurs in a unique environment, containing microglia, oligodendrocytes, astrocytes, and neurons. Although a neuroinflammatory response has been documented in brain metastasis, its contribution to cancer progression and therapy remains poorly understood. Using an experimental brain metastasis model, we characterized the brai...

  15. Astrocytes, Synapses and Brain Function: A Computational Approach

    Science.gov (United States)

    Nadkarni, Suhita

    2006-03-01

    Modulation of synaptic reliability is one of the leading mechanisms involved in long- term potentiation (LTP) and long-term depression (LTD) and therefore has implications in information processing in the brain. A recently discovered mechanism for modulating synaptic reliability critically involves recruitments of astrocytes - star- shaped cells that outnumber the neurons in most parts of the central nervous system. Astrocytes until recently were thought to be subordinate cells merely participating in supporting neuronal functions. New evidence, however, made available by advances in imaging technology has changed the way we envision the role of these cells in synaptic transmission and as modulator of neuronal excitability. We put forward a novel mathematical framework based on the biophysics of the bidirectional neuron-astrocyte interactions that quantitatively accounts for two distinct experimental manifestation of recruitment of astrocytes in synaptic transmission: a) transformation of a low fidelity synapse transforms into a high fidelity synapse and b) enhanced postsynaptic spontaneous currents when astrocytes are activated. Such a framework is not only useful for modeling neuronal dynamics in a realistic environment but also provides a conceptual basis for interpreting experiments. Based on this modeling framework, we explore the role of astrocytes for neuronal network behavior such as synchrony and correlations and compare with experimental data from cultured networks.

  16. The effects of trypsin on rat brain astrocyte activation.

    Directory of Open Access Journals (Sweden)

    Masoud Fereidoni

    2013-12-01

    Full Text Available Astrocytes are cells within the central nervous system which are activated in a wide spectrum of infections, and autoimmune and neurodegenerative diseases. In pathologic states, they produce inflammatory cytokines, chemokines, and nitric oxide (NO, and sometimes they induce apoptosis. Their protease-activated receptors (PARs can be activated by proteases, e.g. thrombin and trypsin, which are important in brain inflammation. The current study aimed to investigate the effects of different concentrations of trypsin (1 to 100U/ml on cultured astrocytes.In the present study, two-day rat infants' brains were isolated and homogenized after meninges removal, then cultivated in DMEM + 10% FBS medium. 10 days later, astrocytes were harvested and recultivated for more purification (up to 95%, using Immunocytochemistry method, in order to be employed for tests. They were affected by different concentrations of trypsin (1, 5, 10, 15, 20, 40, 60, 80, and 100 U/ml. To reveal the inflammation progress, NO concentrations (the Griess test were assessed after 24 and 48 hours.The results showed that trypsin concentration up to 20 U/ml caused a significant increase in NO, in a dose-dependent manner, on cultured astrocytes (P < 0.001. Trypsin 20 U/ml increased NO production fivefold the control group (P < 0.001. At higher concentrations than 20 U/ml, NO production diminished (P < 0.001. At 100 U/ml, NO production was less than the control group (P < 0.001.Inflammatory effects of trypsin 5-20 U/ml are probably due to the stimulation of astrocytes' PAR-2 receptors and the increasing of the activation of NF-κB, PKC, MAPKs. Stimulation of astrocytes' PAR-2 receptors causes an increase in iNOS activation which in turn leads to NO production. However, higher trypsin concentration possibly made astrocyte apoptosis; therefore, NO production diminished. These assumptions need to be further investigated.

  17. Integrated Brain Circuits: Astrocytic Networks Modulate Neuronal Activity and Behavior

    Science.gov (United States)

    Halassa, Michael M.; Haydon, Philip G.

    2011-01-01

    The past decade has seen an explosion of research on roles of neuron-astrocyte interactions in the control of brain function. We highlight recent studies performed on the tripartite synapse, the structure consisting of pre- and postsynaptic elements of the synapse and an associated astrocytic process. Astrocytes respond to neuronal activity and neuro-transmitters, through the activation of metabotropic receptors, and can release the gliotransmitters ATP, D-serine, and glutamate, which act on neurons. Astrocyte-derived ATP modulates synaptic transmission, either directly or through its metabolic product adenosine. D-serine modulates NMDA receptor function, whereas glia-derived glutamate can play important roles in relapse following withdrawal from drugs of abuse. Cell type–specific molecular genetics has allowed a new level of examination of the function of astrocytes in brain function and has revealed an important role of these glial cells that is mediated by adenosine accumulation in the control of sleep and in cognitive impairments that follow sleep deprivation. PMID:20148679

  18. Epilepsy and Brain Tumors

    Institute of Scientific and Technical Information of China (English)

    Zhi-yi Sha

    2009-01-01

    @@ Epidemiology It is estimated 61,414 new cases of primary brain tumors are expected to be diagnosed in 2009 in the U.S. The incidence statistic of 61,414 persons diagnosed per year includes both malignant (22,738) and non-malignant (38,677) brain tumors. (Data from American Brain Tumor Association). During the years 2004-2005, approximately 359,000 people in the United States were living with the diagnosis of a primary brain or central nervous system tumor. Specifically, more than 81,000 persons were living with a malignant tumor, more than 267,000 persons with a benign tumor. For every 100,000 people in the United States, approximately 131 are living following the diagnosis of a brain tumor. This represents a prevalence rate of 130.8 per 100,000 person years[1].

  19. Glutamate metabolism in the brain focusing on astrocytes

    DEFF Research Database (Denmark)

    Schousboe, Arne; Scafidi, Susanna; Bak, Lasse Kristoffer;

    2014-01-01

    Metabolism of glutamate, the main excitatory neurotransmitter and precursor of GABA, is exceedingly complex and highly compartmentalized in brain. Maintenance of these neurotransmitter pools is strictly dependent on the de novo synthesis of glutamine in astrocytes which requires both the anaplero...

  20. Brain Tumor Statistics

    Science.gov (United States)

    ... About Us Our Founders Board of Directors Staff Leadership Strategic Plan Financials News Press Releases Headlines Newsletter ABTA ... About Us Our Founders Board of Directors Staff Leadership Strategic Plan Financials News Careers Brain Tumor Information Brain ...

  1. Brain tumor - children

    Science.gov (United States)

    Glioblastoma multiforme - children; Ependymoma - children; Glioma - children; Astrocytoma - children; Medulloblastoma - children; Neuroglioma - children; Oligodendroglioma - children; Meningioma - children; Cancer - brain tumor (children)

  2. Phenotypic Heterogeneity and Plasticity of Isocortical and Hippocampal Astrocytes in the Human Brain

    OpenAIRE

    Sosunov, Alexander A.; Wu, Xiaoping; Tsankova, Nadejda M.; Guilfoyle, Eileen; Guy M McKhann; Goldman, James E.

    2014-01-01

    To examine the diversity of astrocytes in the human brain, we immunostained surgical specimens of temporal cortex and hippocampus and autopsy brains for CD44, a plasma membrane protein and extracellular matrix receptor. CD44 antibodies outline the details of astrocyte morphology to a degree not possible with glial fibrillary acidic protein (GFAP) antibodies. CD44+ astrocytes could be subdivided into two groups. First, CD44+ astrocytes with long processes were consistently found in the subpial...

  3. Direct Signaling from Astrocytes to Neurons in Cultures of Mammalian Brain Cells

    Science.gov (United States)

    Nedergaard, Maiken

    1994-03-01

    Although astrocytes have been considered to be supportive, rather than transmissive, in the adult nervous system, recent studies have challenged this assumption by demonstrating that astrocytes possess functional neurotransmitter receptors. Astrocytes are now shown to directly modulate the free cytosolic calcium, and hence transmission characteristics, of neighboring neurons. When a focal electric field potential was applied to single astrocytes in mixed cultures of rat forebrain astrocytes and neurons, a prompt elevation of calcium occurred in the target cell. This in turn triggered a wave of calcium increase, which propagated from astrocyte to astrocyte. Neurons resting on these astrocytes responded with large increases in their concentration of cytosolic calcium. The gap junction blocker octanol attenuated the neuronal response, which suggests that the astrocytic-neuronal signaling is mediated through intercellular connections rather than synaptically. This neuronal response to local astrocytic stimulation may mediate local intercellular communication within the brain.

  4. Brain Tumor Symptoms

    Science.gov (United States)

    ... experience symptoms associated with their tumor(s) and/or treatment(s). People with brain tumors often suffer from: Headaches Seizures Sensory (touch) and motor (movement control) loss Deep venous thrombosis (DVT, or blood clot) Hearing loss Vision loss ...

  5. The effects of trypsin on rat brain astrocyte activation

    OpenAIRE

    Masoud Fereidoni; Farzaneh Sabouni; Ali Moghimi; Shirin Hosseini

    2013-01-01

    Background Astrocytes are cells within the central nervous system which are activated in a wide spectrum of infections, and autoimmune and neurodegenerative diseases. In pathologic states, they produce inflammatory cytokines, chemokines, and nitric oxide (NO), and sometimes they induce apoptosis. Their protease-activated receptors (PARs) can be activated by proteases, e.g. thrombin and trypsin, which are important in brain inflammation. The current study aimed to investigate the effects of di...

  6. Understanding Brain Tumors

    Science.gov (United States)

    ... Our Mission Advance Research Clinical Trial Endpoints Defeat GBM Oligo Research Fund Pediatric Initiatives Funded Research & Accomplishments ... no symptoms when their brain tumor is discovered Recurrent headaches Issues with vision Seizures Changes in personality ...

  7. Brain Tumor Risk Factors

    Science.gov (United States)

    ... for example), unusual symptoms such as headaches or short-term memory loss can be investigated with your family history in mind. Click here to view our webinars on Causes and Risk Factors of Brain Tumors. Additional information ...

  8. Abundance of Flt3 and its ligand in astrocytic tumors

    Directory of Open Access Journals (Sweden)

    Eßbach C

    2013-05-01

    Full Text Available C Eßbach,1 N Andrae,1 D Pachow,1 J-P Warnke,2 A Wilisch-Neumann,1 E Kirches,1 C Mawrin11Department of Neuropathology, Otto-von-Guericke University, Magdeburg, 2Department of Neurosurgery, Paracelsus Hospital, Zwickau, GermanyBackground: Molecular targeted therapies for astrocytic tumors are the subject of growing research interest, due to the limited response of these tumors, especially glioblastoma multiforme, to conventional chemotherapeutic regimens. Several of these approaches exploit the inhibition of receptor tyrosine kinases. To date, it has not been elucidated if fms-like tyrosine kinase-3 (Flt3 and its natural ligand (Flt3L are expressed in astrocytic tumors, although some of the clinically intended small-molecule receptor tyrosine kinase inhibitors affect Flt3, while others do not. More importantly, the recent proof of principle for successful stimulation of the immune system against gliomas in preclinical models via local Flt3L application requires elucidation of this receptor tyrosine kinase pathway in these tumors in more detail. This therapy is based on recruitment of Flt3-positive dendritic cells, but may be corroborated by activity of this signaling pathway in glioma cells.Methods: Receptor and ligand expression was analyzed by real-time polymerase chain reaction in 31 astrocytic tumors (six diffuse and 11 anaplastic astrocytomas, 14 glioblastomas derived from patients of both genders and in glioblastoma cell lines. The two most common activating mutations of the Flt3 gene, ie, internal tandem duplication and D835 point mutation, were assessed by specific polymerase chain reaction.Results: A relatively high abundance of Flt3L mRNA (4%–6% of the reference, β2 microglobulin could be demonstrated in all tumor samples. Flt3 expression could generally be demonstrated by 40 specific polymerase chain reaction cycles and gel electrophoresis in 87% of the tumors, including all grades, although the small quantities of the receptor did

  9. In vivo astrocytic Ca2+ signaling in health and brain disorders

    OpenAIRE

    Ding, Shinghua

    2013-01-01

    Astrocytes are the predominant glial cell type in the CNS. Although astrocytes are electrically nonexcitable, their excitability is manifested by their Ca2+ signaling, which serves as a mediator of neuron–glia bidirectional interactions via tripartite synapses. Studies from in vivo two-photon imaging indicate that in healthy animals, the properties of spontaneous astrocytic Ca2+ signaling are affected by animal species, age, wakefulness and the location of astrocytes in the brain. Intercellul...

  10. Impairments of astrocytes are involved in the D-galactose-induced brain aging

    International Nuclear Information System (INIS)

    Astrocyte dysfunction is implicated in course of various age-related neurodegenerative diseases. Chronic injection of D-galactose can cause a progressive deterioration in learning and memory capacity and serve as an animal model of aging. To investigate the involvement of astrocytes in this model, oxidative stress biomarkers, biochemical and pathological changes of astrocytes were examined in the hippocampus of the rats with six weeks of D-galactose injection. D-galactose-injected rats displayed impaired antioxidant systems, an increase in nitric oxide levels, and a decrease in reduced glutathione levels. Consistently, western blotting and immunostaining of glial fibrillary acidic protein showed extensive activation of astrocytes. Double-immunofluorescent staining further showed activated astrocytes highly expressed inducible nitric oxide synthase. Electron microscopy demonstrated the degeneration of astrocytes, especially in the aggregated area of synapse and brain microvessels. These findings indicate that impairments of astrocytes are involved in oxidative stress-induced brain aging by chronic injection of D-galactose

  11. Adult brain tumors

    International Nuclear Information System (INIS)

    Radiotherapy plays an important role in the management of adults with brain tumors. This refresher course will focus on a wide variety of benign and malignant brain neoplasms and how contemporary radiotherapy affects survival. In each case the intent of radiation therapy is to destroy the neoplasm without affecting normal tissues. However, for many neoplasms serial post-treatment scans may show little change, and success is often measured more by absence of tumor progression than by scan normalization. Successful outcome after radiation therapy of brain tumors usually requires that (1) there is no tumor extension beyond the target volume, (2) adequate dose is delivered to the target volume, and (3) normal tissue tolerance doses are not exceeded. For some tumors it may be impossible to satisfy all three criteria. Three-dimensional treatment planning based on MRI or CT makes it possible to guarantee delivery of the full dose of radiation to gross tumor while minimizing the volume of normal tissue receiving high dose. Acceptable dose conformity can often be achieved with 2-4 static beams or arcs and are usually preferable to opposed lateral fields. Examples of planning solutions for a variety of tumor types, sizes, and anatomic location will be given. For some tumors, protocols involving substantial dose escalation require a large number of non-coplanar x-ray beams or particle therapy. Several concepts and techniques which relate to the treatment of brain tumors will be discussed, including conformal radiotherapy, brachytherapy, radiosurgery, fractionated stereotactic radiotherapy, altered fractionation, inverse treatment planning, re-irradiation and biologically effective dose (BED)

  12. Brain tumor stem cells.

    Science.gov (United States)

    Palm, Thomas; Schwamborn, Jens C

    2010-06-01

    Since the end of the 'no-new-neuron' theory, emerging evidence from multiple studies has supported the existence of stem cells in neurogenic areas of the adult brain. Along with this discovery, neural stem cells became candidate cells being at the origin of brain tumors. In fact, it has been demonstrated that molecular mechanisms controlling self-renewal and differentiation are shared between brain tumor stem cells and neural stem cells and that corruption of genes implicated in these pathways can direct tumor growth. In this regard, future anticancer approaches could be inspired by uncovering such redundancies and setting up treatments leading to exhaustion of the cancer stem cell pool. However, deleterious effects on (normal) neural stem cells should be minimized. Such therapeutic models underline the importance to study the cellular mechanisms implicated in fate decisions of neural stem cells and the oncogenic derivation of adult brain cells. In this review, we discuss the putative origins of brain tumor stem cells and their possible implications on future therapies. PMID:20370314

  13. Human Brain Astrocytes Mediate TRAIL-mediated Apoptosis after Treatment with IFN-γ

    OpenAIRE

    Lee, Jeonggi; Shin, Jeon-Soo; Choi, In-Hong

    2006-01-01

    TNF-related apoptosis inducing ligand (TRAIL) expressions were studied in primary human brain astrocytes in response to pro-inflammatory cytokines. When astrocytes were treated with IL-1β, TNF-α or IFN-γ, TRAIL was induced in cultured fetal astrocytes. In particular, IFN-γ induced the highest levels of TRAIL in cultured astrocytes. When astrocytes were prereated with IFN-γ, they induced apoptosis in TRAIL-sensitive Peer cells. Our results suggest that IFN-γ modulates the expression of TRAIL i...

  14. Adult brain tumors

    International Nuclear Information System (INIS)

    Radiotherapy plays an important role in the management of adults with brain tumors. This refresher course will focus on a variety of benign and malignant brain neoplasms and how contemporary radiotherapy affects outcome. Successful outcome after radiotherapy requires that (1) there is no tumor extension beyond the selected target volume, (2) adequate dose is delivered to the target volume, and (3) normal tissue tolerance dose is not exceeded. For many neoplasms serial post-treatment scans may show little change, and success is often measured more by absence of tumor progression than by scan normalization. Three-dimensional treatment planning based on MRI or CT makes it possible to guarantee delivery of the full prescription dose to gross tumor while minimizing the volume of normal tissue receiving high dose. Acceptable dose conformity can often be achieved with 2-4 static beams or arcs, which is usually preferable to opposed lateral fields. Protocols involving substantial dose escalation require a large number of non-coplanar x-ray beams or particle therapy. This course will cover important concepts and techniques which relate to the treatment of brain tumors, including conformal radiotherapy, brachytherapy, radiosurgery, fractionated stereotactic radiotherapy, altered fractionation, inverse treatment planning, re-irradiation, and biologically effective dose (BED). Examples of planning solutions for a variety of tumor types, size and anatomical locations will be given

  15. Children's Brain Tumor Foundation

    Science.gov (United States)

    ... 3 families will mourn the loss of their child to a brain or spinal cord tumor. Friends, family and community will try to make sense of an untimely death and the unfulfilled promise of a life. 6 families will transition to survivorship. A mother may be too exhausted from providing constant care ...

  16. Drugs Approved for Brain Tumors

    Science.gov (United States)

    ... Ask about Your Treatment Research Drugs Approved for Brain Tumors This page lists cancer drugs approved by the ... that are not listed here. Drugs Approved for Brain Tumors Afinitor (Everolimus) Afinitor Disperz (Everolimus) Avastin (Bevacizumab) Becenum ( ...

  17. Adult brain tumors

    International Nuclear Information System (INIS)

    Radiotherapy plays an important role in the management of adults with brain tumors. This refresher course will focus on a variety of benign and malignant brain neoplasms and how contemporary radiotherapy affects outcome. Successful outcome after radiotherapy requires that (1) there is no tumor extension beyond the selected target volume, (2) adequate dose is delivered to the target volume, and (3) normal tissue tolerance dose is not exceeded. For many neoplasms serial post-treatment scans may show little change, and success is often measured more by absence of tumor progression than by scan normalization. Three-dimensional treatment planning based on MRI or CT makes it possible to guarantee delivery of the full prescription dose to gross tumor while minimizing the volume of normal tissue receiving high dose. Acceptable dose conformity can often be achieved with 2-4 static beams or arcs, which is usually preferable to opposed lateral fields. Protocols involving substantial dose escalation require a large number of non-coplanar x-ray beams or particle therapy. This course will cover important concepts and techniques which relate to the treatment of brain tumors, including conformal radiotherapy, brachytherapy, radiosurgery, fractionated stereotactic radiotherapy, altered fractionation, inverse treatment planning, re-irradiation, and biologically effective dose (BED). Examples of planning solutions for a variety of tumor types, size and anatomical locations will be given. Note: I will incorporate examples of interesting, difficult and unusual cases from other practices as time permits, provided slides and descriptive materials are sent to me in advance of the course

  18. Intraaxial brain tumors

    International Nuclear Information System (INIS)

    The incidence of primary intracranial tumors in the United States is approximately 15,0000 new cases per year. It has been estimated that 80--85% of all intracranial tumors occur in adults; the majority are situated in the supratentorial compartment. In the pediatric population, intracranial tumors are extraordinarily common---the CNS is the second most common site of pediatric neoplasia. Excluding the first year of life and adolescence, the location of intracranial tumors in the pediatric age group is infratentorial in 60--70% of cases, of which 75% involve the cerebellum and 25% reside in the brainstem. The limitations of neuroimaging are often revealed by understanding the microscopic pathology of these lesions, just as the neuropathologist would find if he or she relied solely on gross pathology. The general correlation between pathology and imaging will be stressed in this paper. Innumerable schemes for tumor classification have been devised; unfortunately, no classification is perfect. For the purposes of this discussion, the author has modified the proposed classifications of tumors in an attempt to combine typical neuroanatomic sites with the complex divisions traditionally formed on the basis of histopathology, since it is well recognized that the clinical behavior of brain tumors can depend largely on their sites of origin

  19. Expression and cellular function of vSNARE proteins in brain astrocytes.

    Science.gov (United States)

    Ropert, N; Jalil, A; Li, D

    2016-05-26

    Gray matter protoplasmic astrocytes, a major type of glial cell in the mammalian brain, extend thin processes ensheathing neuronal synaptic terminals. Albeit electrically silent, astrocytes respond to neuronal activity with Ca(2+) signals that trigger the release of gliotransmitters, such as glutamate, d-serine, and ATP, which modulate synaptic transmission. It has been suggested that the astrocytic processes, together with neuronal pre- and post-synaptic elements, constitute a tripartite synapse, and that astrocytes actively regulate information processing. Astrocytic vesicles expressing VAMP2 and VAMP3 vesicular SNARE (vSNARE) proteins have been suggested to be a key feature of the tripartite synapse and mediate gliotransmitter release through Ca(2+)-regulated exocytosis. However, the concept of exocytotic release of gliotransmitters by astrocytes has been challenged. Here we review studies investigating the expression profile of VAMP2 and VAMP3 vSNARE proteins in rodent astrocytes, and the functional implication of VAMP2/VAMP3 vesicles in astrocyte signaling. We also discuss our recent data suggesting that astrocytic VAMP3 vesicles regulate the trafficking of glutamate transporters at the plasma membrane and glutamate uptake. A better understanding of the functional consequences of the astrocytic vSNARE vesicles on glutamate signaling, neuronal excitability and plasticity, will require the development of new strategies to selectively interrogate the astrocytic vesicles trafficking in vivo. PMID:26518463

  20. Epidemiological features of brain tumors

    Directory of Open Access Journals (Sweden)

    Živković Nenad

    2013-01-01

    Full Text Available Brain tumors account for 1.4% of all cancers and 2.4% of all cancer-related deaths. The incidence of brain tumors varies and it is higher in developed countries of Western Europe, North America, Australia and New Zealand. In Serbia, according to data from 2009, malignant brain tumors account for 2. 2 of all tumors, and from all cancer­related deaths, 3.2% is caused by malignant brain tumors. According to recent statistical reports, an overall incidence of brain tumors for benign and malignant tumors combined is 18.71 per 100,000 persons/year. The most common benign brain tumor in adults is meningioma, which is most present in women, and the most common malignant tumor is glioblastoma, which is most present in adult men. Due to high mortality, especially in patients diagnosed with glioblastoma and significant brain tumor morbidity, there is a constant interest in understanding its etiology in order to possibly prevent tumor occurrence in future and enable more efficient treatment strategies for this fatal brain disease. Despite the continuously growing number of epidemiological studies on possible factors of tumor incidence, the etiology remains unclear. The only established environmental risk factor of gliomas is ionizing radiation exposure. Exposure to radiofrequency electromagnetic fields via cell phone use has gained a lot of attention as a potential risk factor of brain tumor development. However, studies have been inconsistent and inconclusive, so more definite results are still expected.

  1. Central role of maladapted astrocytic plasticity in ischemic brain edema formation

    Directory of Open Access Journals (Sweden)

    Yu-Feng eWang

    2016-05-01

    Full Text Available Brain edema formation and the ensuing brain damages are the major cause of high mortality and long term disability following the occurrence of ischemic stroke. In this process, oxygen and glucose deprivation and the ensuing reperfusion injury play primary roles. In response to the ischemic insult, the neurovascular unit experiences both intracellular and extracellular edemas; the two processes are interactive closely under the driving of maladapted astrocytic plasticity. The astrocytic plasticity includes both morphologic and functional plasticity. The former involves a reactive gliosis and the ensuing glial retraction. It relates to the capacity of astrocytes to buffer changes in extracellular chemical levels, particularly K+ and glutamate, as well as the integrity of the blood-brain barrier. The latter involves the expression and activity of a series of ion and water transport proteins. These molecules are grouped together around glial fibrillary acidic protein and water channel protein aquaporin 4 to form functional networks, regulate hydromineral balance across cell membranes and maintain the integrity of the blood-brain barrier. Intense ischemic challenges can disrupt these capacities of astrocytes and result in their maladaptation. The maladapted astrocytic plasticity in ischemic stroke cannot only disrupt the hydromineral homeostasis across astrocyte membrane and the blood-brain barrier, but also lead to disorders of the whole neurovascular unit. This review focuses on how the maladapted astrocytic plasticity in ischemic stroke plays the central role in the brain edema formation.

  2. Assessment of C-phycocyanin effect on astrocytes-mediated neuroprotection against oxidative brain injury using 2D and 3D astrocyte tissue model.

    Science.gov (United States)

    Min, Seul Ki; Park, Jun Sang; Luo, Lidan; Kwon, Yeo Seon; Lee, Hoo Cheol; Shim, Hyun Jung; Kim, Il-Doo; Lee, Ja-Kyeong; Shin, Hwa Sung

    2015-01-01

    Drugs are currently being developed to attenuate oxidative stress as a treatment for brain injuries. C-phycocyanin (C-Pc) is an antioxidant protein of green microalgae known to exert neuroprotective effects against oxidative brain injury. Astrocytes, which compose many portions of the brain, exert various functions to overcome oxidative stress; however, little is known about how C-Pc mediates the antioxidative effects of astrocytes. In this study, we revealed that C-Pc intranasal administration to the middle cerebral artery occlusion (MCAO) rats ensures neuroprotection of ischemic brain by reducing infarct size and improving behavioral deficits. C-Pc also enhanced viability and proliferation but attenuated apoptosis and reactive oxygen species (ROS) of oxidized astrocytes, without cytotoxicity to normal astrocytes and neurons. To elucidate how C-Pc leads astrocytes to enhance neuroprotection and repair of ischemia brain, we firstly developed 3D oxidized astrocyte model. C-Pc had astrocytes upregulate antioxidant enzymes such as SOD and catalase and neurotrophic factors BDNF and NGF, while alleviating inflammatory factors IL-6 and IL-1β and glial scar. Additionally, C-Pc improved viability of 3D oxidized neurons. In summary, C-Pc was concluded to activate oxidized astrocytes to protect and repair the ischemic brain with the combinatorial effects of improved antioxidative, neurotrophic, and anti-inflammatory mechanisms. PMID:26399322

  3. Co-culture of astrocytes with neurons from injured brain A time-dependent dichotomy

    Institute of Scientific and Technical Information of China (English)

    Xiaojing Xu; Min Wang; Jing Liu; Jingya Lv; Yanan Hu; Huanxiang Zhang

    2011-01-01

    As supportive cells for neuronal growth and development, much effort has been devoted to the role of astrocytes in the normal state. However, the effect of the astrocytes after injury remains elusive. In the present study, neurons isolated from the subventricular zone of injured neonatal rat brains were co-cultured with astrocytes. After 6 days, these astrocytes showed a mature neuron-like appearance and the number of survivingneurons, primary dendrites and total branches was significantly higher than those at 3 days. The neurons began to shrink at 9 days after co-culture with shorter and thinner processes and the number of primary dendrites and total branches was significantly reduced. These experimental findings indicate that astrocytes in the injured brain promote the development of neurons in the early stages of co-culture while these cells reversely inhibit neuronal growth and development at the later states.

  4. Modelling the anesthetized brain with ensembles of neuronal and astrocytic oscillators

    Science.gov (United States)

    Hansard, T.; Hale, A. C.; Stefanovska, A.

    2013-01-01

    We propose a minimalistic model of the anesthetized brain in order to study the generation of rhythms observed in electroencephalograms (EEGs) recorded from anesthetized humans. We propose that non-neuronal brain cells-astrocytes-play an important role in brain dynamics and that oscillation-based models may provide a simple way to study such dynamics. The model is capable of replicating the main features (i.e. slow and alpha oscillations) observed in EEGs. In addition, this model suggests that astrocytes are integral to the generation of slow EEG (˜0.7 Hz) rhythms. By including astrocytes in the model we take a first step towards investigating the interaction of the brain and cardiovasular system which are primarily connected via astrocytes. The model also illustrates that rich nonlinear dynamics can arise from basic oscillatory "building blocks" and therefore complex systems may be modelled in an uncomplicated way.

  5. Astrocytic Ephrin-B1 Regulates Synapse Remodeling Following Traumatic Brain Injury

    OpenAIRE

    Nikolakopoulou, Angeliki M.; Koeppen, Jordan; Garcia, Michael; Leish, Joshua; Obenaus, Andre; Iryna M Ethell

    2016-01-01

    Traumatic brain injury (TBI) can result in tissue alterations distant from the site of the initial injury, which can trigger pathological changes within hippocampal circuits and are thought to contribute to long-term cognitive and neuropsychological impairments. However, our understanding of secondary injury mechanisms is limited. Astrocytes play an important role in brain repair after injury and astrocyte-mediated mechanisms that are implicated in synapse development are likely important in ...

  6. Sulfonylurea Receptor 1 Contributes to the Astrocyte Swelling and Brain Edema in Acute Liver Failure

    OpenAIRE

    Jayakumar, A.R.; Valdes, V.; Tong, X. Y.; Shamaladevi, N.; W Gonzalez; Norenberg, M.D.

    2014-01-01

    Astrocyte swelling (cytotoxic brain edema) is the major neurological complication of acute liver failure (ALF), a condition in which ammonia has been strongly implicated in its etiology. Ion channels and transporters are known to be involved in cell volume regulation and a disturbance in these systems may result in cell swelling. One ion channel known to contribute to astrocyte swelling/brain edema in other neurological disorders is the ATP-dependent, non-selective cation channel (NCCa-ATP ch...

  7. Central Role of Maladapted Astrocytic Plasticity in Ischemic Brain Edema Formation.

    Science.gov (United States)

    Wang, Yu-Feng; Parpura, Vladimir

    2016-01-01

    Brain edema formation and the ensuing brain damages are the major cause of high mortality and long term disability following the occurrence of ischemic stroke. In this process, oxygen and glucose deprivation and the resulting reperfusion injury play primary roles. In response to the ischemic insult, the neurovascular unit experiences both intracellular and extracellular edemas, associated with maladapted astrocytic plasticity. The astrocytic plasticity includes both morphological and functional plasticity. The former involves a reactive gliosis and the subsequent glial retraction. It relates to the capacity of astrocytes to buffer changes in extracellular chemical levels, particularly K(+) and glutamate, as well as the integrity of the blood-brain barrier (BBB). The latter involves the expression and activity of a series of ion and water transport proteins. These molecules are grouped together around glial fibrillary acidic protein (GFAP) and water channel protein aquaporin 4 (AQP4) to form functional networks, regulate hydromineral balance across cell membranes and maintain the integrity of the BBB. Intense ischemic challenges can disrupt these capacities of astrocytes and result in their maladaptation. The maladapted astrocytic plasticity in ischemic stroke cannot only disrupt the hydromineral homeostasis across astrocyte membrane and the BBB, but also leads to disorders of the whole neurovascular unit. This review focuses on how the maladapted astrocytic plasticity in ischemic stroke plays the central role in the brain edema formation. PMID:27242440

  8. NANOROBOTS IN BRAIN TUMOR

    Directory of Open Access Journals (Sweden)

    Sayyed Tarannum, Garje Dattatray H

    2011-02-01

    Full Text Available Nanomedicine is the process of diagnosing, treating, and preventing disease and traumatic injury, of relieving pain, and of preserving and improving human health, using molecular tools and molecular knowledge of the human body. In the relatively near term, nanomedicine can address many important medical problems by using nanoscale-structured materials and simple nanodevices that can be manufactured today, including the interaction of nanostructured materials with biological systems. The authors predict that technology-assisted medicine and robotics in particular, will have a significant impact over the next few decades. Robots will augment the surgeon’s motor performance, diagnosis capability, and senses with haptics (feel, augmented reality (sight, and ultrasound (sound. Robotic devices have been used in cardiac surgery, urology, fetal surgery, pediatrics, neurosurgery, orthopedics, and many other medical disciplines. In this article, we present the Nanorobot drug delivery to brain tumor, paying special attention to the transformation trends of organizations, and the integration of robots in brain tumor and underscoring potential repercussions which may deserve more attention and further research.

  9. Assessment of C-phycocyanin effect on astrocytes-mediated neuroprotection against oxidative brain injury using 2D and 3D astrocyte tissue model

    OpenAIRE

    Seul Ki Min; Jun Sang Park; Lidan Luo; Yeo Seon Kwon; Hoo Cheol Lee; Hyun Jung Shim; Il-Doo Kim; Ja-Kyeong Lee; Hwa Sung Shin

    2015-01-01

    Drugs are currently being developed to attenuate oxidative stress as a treatment for brain injuries. C-phycocyanin (C-Pc) is an antioxidant protein of green microalgae known to exert neuroprotective effects against oxidative brain injury. Astrocytes, which compose many portions of the brain, exert various functions to overcome oxidative stress; however, little is known about how C-Pc mediates the antioxidative effects of astrocytes. In this study, we revealed that C-Pc intranasal administrati...

  10. Imaging of brain tumors

    International Nuclear Information System (INIS)

    The contents are diagnostic approaches, general features of tumors -hydrocephalus, edema, attenuation and/or intensity value, hemorrhage, fat, contrast enhancement, intra-axial supratentorial tumors - tumors of glial origin, oligodendrogliomas, ependymomas, subependymomas, subependymal giant cell astrocytomas, choroid plexus papilloma; midline tumors - colloid cysts, craniopharyngiomas; pineal region tumors and miscellaneous tumors i.e. primary intracerebral lymphoma, primitive neuroectodermal tumors, hemangioblastomas; extraaxial tumors - meningiomas; nerve sheath tumors -schwannomas, epidermoids, dermoids, lipomas, arachnoid cysts; metastatic tumors (8 refs.)

  11. Generation of primary cultures of bovine brain endothelial cells and setup of cocultures with rat astrocytes

    DEFF Research Database (Denmark)

    Helms, Hans C; Brodin, Birger

    2014-01-01

    -brain barrier. The present protocol describes the setup of an in vitro coculture model based on primary cultures of endothelial cells from bovine brain microvessels and primary cultures of rat astrocytes. The model displays a high electrical tightness and expresses blood-brain barrier marker proteins....

  12. A Role for Astrocytes in Sensing the Brain Microenvironment and Neuro-Metabolic Integration.

    Science.gov (United States)

    Teschemacher, A G; Gourine, A V; Kasparov, S

    2015-12-01

    Astrocytes occupy a strategic position in the brain where they can act as an interface between neurones and blood vessels, and neurones and the cerebro-spinal fluid. This location is ideal for functioning as interoceptors, as they may sense changes in brain microenvironment and contribute to the adaptive homeostatic responses coordinated by neuronal networks. Here we briefly review some of the recent evidence, which implicates the involvement of astrocytes in the central nervous control of breathing, sympathetic tone and blood glucose levels. L-lactate appears a potentially crucial signaling molecule in the communication between astrocytes and neurones. Based on the available evidence, we conclude that astrocytes contribute to the homeostasis by playing a significant role in the brain's interoceptive mechanisms. PMID:25837670

  13. Efficient gene delivery and selective transduction of astrocytes in the mammalian brain using viral vectors

    Directory of Open Access Journals (Sweden)

    Nicolas eMerienne

    2013-07-01

    Full Text Available Astrocytes are now considered as key players in brain information processing because of their newly discovered roles in synapse formation and plasticity, energy metabolism and blood flow regulation. However, our understanding of astrocyte function is still fragmented compared to other brain cell types. A better appreciation of the biology of astrocytes requires the development of tools to generate animal models in which astrocyte-specific proteins and pathways can be manipulated. In addition, it is becoming increasingly evident that astrocytes are also important players in many neurological disorders. Targeted modulation of protein expression in astrocytes would be critical for the development of new therapeutic strategies. Gene transfer is valuable to target a subpopulation of cells and explore their function in experimental models. In particular, viral-mediated gene transfer provides a rapid, highly flexible and cost-effective, in vivo paradigm to study the impact of genes of interest during CNS development or in adult animals. We will review the different strategies that led to the recent development of efficient viral vectors that can be successfully used to selectively transduce astrocytes in the mammalian brain.

  14. Living with a Brain Tumor

    Science.gov (United States)

    ... when you have been diagnosed with a brain tumor diagnosis. Dealing with changes to your appearance – such as losing your hair or losing weight is difficult for most of us. Keep in mind that your life is not so much ... with a brain tumor may mean rethinking your work and professional goals, ...

  15. Brain Tumor Epidemiology Consortium (BTEC)

    Science.gov (United States)

    The Brain Tumor Epidemiology Consortium is an open scientific forum organized to foster the development of multi-center, international and inter-disciplinary collaborations that will lead to a better understanding of the etiology, outcomes, and prevention of brain tumors.

  16. The metabolism of malate by cultured rat brain astrocytes

    International Nuclear Information System (INIS)

    Since malate is known to play an important role in a variety of functions in the brain including energy metabolism, the transfer of reducing equivalents and possibly metabolic trafficking between different cell types; a series of biochemical determinations were initiated to evaluate the rate of 14CO2 production from L-[U-14C]malate in rat brain astrocytes. The 14CO2 production from labeled malate was almost totally suppressed by the metabolic inhibitors rotenone and antimycin A suggesting that most of malate metabolism was coupled to the electron transport system. A double reciprocal plot of the 14CO2 production from the metabolism of labeled malate revealed biphasic kinetics with two apparent Km and Vmax values suggesting the presence of more than one mechanism of malate metabolism in these cells. Subsequent experiments were carried out using 0.01 mM and 0.5 mM malate to determine whether the addition of effectors would differentially alter the metabolism of high and low concentrations of malate. Effectors studied included compounds which could be endogenous regulators of malate metabolism and metabolic inhibitors which would provide information regarding the mechanisms regulating malate metabolism. Both lactate and aspartate decreased 14CO2 production from malate equally. However, a number of effectors were identified which selectively altered the metabolism of 0.01 mM malate including aminooxyacetate, furosemide, N-acetylaspartate, oxaloacetate, pyruvate and glucose, but had little or no effect on the metabolism of 0.5 mM malate. In addition, alpha-ketoglutarate and succinate decreased 14CO2 production from 0.01 mM malate much more than from 0.5 mM malate. In contrast, a number of effectors altered the metabolism of 0.5 mM malate more than 0.01 mM. These included methionine sulfoximine, glutamate, malonate, alpha-cyano-4-hydroxycinnamate and ouabain

  17. Cellular pathways of energy metabolism in the brain: is glucose used by neurons or astrocytes?

    Science.gov (United States)

    Nehlig, Astrid; Coles, Jonathan A

    2007-09-01

    Most techniques presently available to measure cerebral activity in humans and animals, i.e. positron emission tomography (PET), autoradiography, and functional magnetic resonance imaging, do not record the activity of neurons directly. Furthermore, they do not allow the investigator to discriminate which cell type is using glucose, the predominant fuel provided to the brain by the blood. Here, we review the experimental approaches aimed at determining the percentage of glucose that is taken up by neurons and by astrocytes. This review is integrated in an overview of the current concepts on compartmentation and substrate trafficking between astrocytes and neurons. In the brain in vivo, about half of the glucose leaving the capillaries crosses the extracellular space and directly enters neurons. The other half is taken up by astrocytes. Calculations suggest that neurons consume more energy than do astrocytes, implying that astrocytes transfer an intermediate substrate to neurons. Experimental approaches in vitro on the honeybee drone retina and on the isolated vagus nerve also point to a continuous transfer of intermediate metabolites from glial cells to neurons in these tissues. Solid direct evidence of such transfer in the mammalian brain in vivo is still lacking. PET using [(18)F]fluorodeoxyglucose reflects in part glucose uptake by astrocytes but does not indicate to which step the glucose taken up is metabolized within this cell type. Finally, the sequence of metabolic changes occurring during a transient increase of electrical activity in specific regions of the brain remains to be clarified. PMID:17659529

  18. Treatment of Pediatric Brain Tumors

    OpenAIRE

    Karajannis, Matthias; Allen, Jeffrey C.; Newcomb, Elizabeth W.

    2008-01-01

    Over the past decades considerable advances have been made in neurosurgery, radiotherapy and chemotherapy resulting in improved survival and cure rates for children with brain tumors. Here we review four of the most common subtypes of pediatric brain tumors, low-grade and high-grade astrocytomas, medulloblastomas and ependymomas, highlighting their molecular features regarding their tumor biology and promising potential therapeutic targets that may hold promise for finding new “molecularly ta...

  19. Astrocyte cultures derived from human brain tissue express angiotensinogen mRNA

    Energy Technology Data Exchange (ETDEWEB)

    Milsted, A.; Barna, B.P.; Ransohoff, R.M.; Brosnihan, K.B.; Ferrario, C.M. (Cleveland Clinic Foundation, OH (USA))

    1990-08-01

    The authors have identified human cultured cell lines that are useful for studying angiotensinogen gene expression and its regulation in the central nervous system. A model cell system of human central nervous system origin expressing angiotensinogen has not previously been available. Expression of angiotensinogen mRNA appears to be a basal property of noninduced human astrocytes, since astrocytic cell lines derived from human glioblastomas or nonneoplastic human brain tissue invariably produced angiotensinogen mRNA. In situ hybridization histochemistry revealed that angiotensinogen mRNA production was not limited to a subpopulation of astrocytes because >99% of cells in these cultures contained angiotensinogen mRNA. These cell lines will be useful in studies of the molecular mechanisms controlling angiotensin synthesis and the role of biologically active angiotensin in the human brain by allowing the authors to examine regulation of expression of the renin-angiotensin system in human astrocyte cultures.

  20. Astrocyte cultures derived from human brain tissue express angiotensinogen mRNA

    International Nuclear Information System (INIS)

    The authors have identified human cultured cell lines that are useful for studying angiotensinogen gene expression and its regulation in the central nervous system. A model cell system of human central nervous system origin expressing angiotensinogen has not previously been available. Expression of angiotensinogen mRNA appears to be a basal property of noninduced human astrocytes, since astrocytic cell lines derived from human glioblastomas or nonneoplastic human brain tissue invariably produced angiotensinogen mRNA. In situ hybridization histochemistry revealed that angiotensinogen mRNA production was not limited to a subpopulation of astrocytes because >99% of cells in these cultures contained angiotensinogen mRNA. These cell lines will be useful in studies of the molecular mechanisms controlling angiotensin synthesis and the role of biologically active angiotensin in the human brain by allowing the authors to examine regulation of expression of the renin-angiotensin system in human astrocyte cultures

  1. Differential erbB signaling in astrocytes from the cerebral cortex and the hypothalamus of the human brain. : ErbB signaling in human astrocytes

    OpenAIRE

    Sharif, Ariane; Duhem-Tonnelle, Véronique; Allet, Cécile; Baroncini, Marc; Loyens, Anne; Kerr-Conte, Julie; Collier, Francis; Blond, Serge; Ojeda, Sergio; Junier, Marie-Pierre; Prévot, Vincent

    2009-01-01

    Studies in rodents have shown that astroglial erbB tyrosine kinase receptors are key regulatory elements in neuron-glia communication. Although both astrocytes and deregulation of erbB functions have been implicated in the pathogenesis of many common human brain disorders, erbB signaling in native human brain astrocytes has never been explored. Taking advantage of our ability to perform primary cultures from the cortex and the hypothalamus of human fetuses, we conducted a thorough analysis of...

  2. Astrocytic modulation of Blood Brain Barrier: Perspectives on Parkinson´s Disease

    Directory of Open Access Journals (Sweden)

    Ricardo eCabezas

    2014-08-01

    Full Text Available TThe blood–brain barrier (BBB is a tightly regulated interface in the Central Nervous System that regulates the exchange of molecules in and out from the brain thus maintaining the CNS homeostasis. It is mainly composed of endothelial cells, pericytes and astrocytes that create a neurovascular unit with the adjacent neurons. Astrocytes are essential for the formation and maintenance of the BBB by providing secreted factors that lead to the adequate association between the cells of the BBB and the formation of strong tight junctions. Under neurological disorders, such as chronic cerebral ischemia, brain trauma, Epilepsy, Alzheimer and Parkinson´s Diseases, a disruption of the BBB takes place, involving a lost in the permeability of the barrier and phenotypical changes in both the endothelial cells and astrocytes. In this aspect, it has been established that the process of reactive gliosis is a common feature of astrocytes during BBB disruption, which has a detrimental effect on the barrier function and a subsequent damage in neuronal survival. In this review we discuss the implications of astrocyte functions in the protection of the BBB, and in the development of Parkinson´s disease and related disorders. Additionally, we highlight the current and future strategies in astrocyte protection aimed at the development of restorative therapies for the BBB in pathological conditions.

  3. Behavioral stress reduces RIP140 expression in astrocyte and increases brain lipid accumulation

    OpenAIRE

    Feng, Xudong; Lin, Yu-Lung; Wei, Li-Na

    2015-01-01

    Receptor-interacting protein 140 (RIP140) is highly expressed in the brain, and acts in neurons and microglia to affect emotional responses. The present study reveals an additional function of RIP140 in the brain, which is to regulate brain lipid homeostasis via its action in astrocytes. We found forced swim stress (FSS) significantly reduces the expression level of RIP140 and elevates cholesterol content in the brain. Mechanistically, FSS elevates endoplasmic reticulum stress, which suppress...

  4. All astrocytes are not created equal—the role of astroglia in brain injury

    OpenAIRE

    Moore, Darcie L; Jessberger, Sebastian

    2013-01-01

    In two recent papers published in Nature Neuroscience and Cell Stem Cells, Magdalena Götz and colleagues shed new light on the in vivo response of glial cells to brain injury and characterize a highly heterogeneous behavior of astrocytes to chronic and acute brain injury.

  5. Glucose-coated gold nanoparticles transfer across human brain endothelium and enter astrocytes in vitro.

    Directory of Open Access Journals (Sweden)

    Radka Gromnicova

    Full Text Available The blood-brain barrier prevents the entry of many therapeutic agents into the brain. Various nanocarriers have been developed to help agents to cross this barrier, but they all have limitations, with regard to tissue-selectivity and their ability to cross the endothelium. This study investigated the potential for 4 nm coated gold nanoparticles to act as selective carriers across human brain endothelium and subsequently to enter astrocytes. The transfer rate of glucose-coated gold nanoparticles across primary human brain endothelium was at least three times faster than across non-brain endothelia. Movement of these nanoparticles occurred across the apical and basal plasma membranes via the cytosol with relatively little vesicular or paracellular migration; antibiotics that interfere with vesicular transport did not block migration. The transfer rate was also dependent on the surface coating of the nanoparticle and incubation temperature. Using a novel 3-dimensional co-culture system, which includes primary human astrocytes and a brain endothelial cell line hCMEC/D3, we demonstrated that the glucose-coated nanoparticles traverse the endothelium, move through the extracellular matrix and localize in astrocytes. The movement of the nanoparticles through the matrix was >10 µm/hour and they appeared in the nuclei of the astrocytes in considerable numbers. These nanoparticles have the correct properties for efficient and selective carriers of therapeutic agents across the blood-brain barrier.

  6. Pathological advances in pediatric brain tumors

    OpenAIRE

    Wang, Li-Feng; Wang, Rui-Fen; Guan, Wen-bin; Yan, Yu

    2015-01-01

    Pediatric brain tumors are the most common solid tumors in children. Compared with brain tumors in adults, pediatric brain tumors have characteristic clinicopathological features and molecular mechanisms. The accurate diagnosis and classification of brain tumors in children is important for patients to have an individualized therapy and to improve the survival rate. With the further study of pediatric brain tumors, there are some new viewpoints on pilocytic astrocytoma (PA), ependymoma,...

  7. Implications of astrocytes in mediating the protective effects of Selective Estrogen Receptor Modulators upon brain damage

    Directory of Open Access Journals (Sweden)

    George E. Barreto

    2015-04-01

    Full Text Available Selective Estrogen Receptor Modulators (SERMs are steroidal or non-steroidal compounds that are already used in clinical practice for the treatment of breast cancer, osteoporosis and menopausal symptoms. While SERMs actions in the breast, bone, and uterus have been well characterized, their actions in the brain are less well understood. Previous works have demonstrated the beneficial effects of SERMs in different chronic neurodegenerative diseases like Alzheimer, Parkinson’s disease and Multiple sclerosis, as well as acute degeneration as stroke and traumatic brain injury. Moreover, these compounds exhibit similar protective actions as those of estradiol in the Central Nervous System, overt any secondary effect. For these reasons, in the past few years, there has been a growing interest in the neuroprotective effects exerted directly or indirectly by SERMs in the SNC. In this context, astrocytes play an important role in the maintenance of brain metabolism, and antioxidant support to neurons, thus indicating that better protection of astrocytes are an important asset targeting neuronal protection. Moreover, various clinical and experimental studies have reported that astrocytes are essential for the neuroprotective effects of SERMs during neuronal injuries, as these cells express different estrogen receptors in cell membrane, demonstrating that part of SERMs effects upon injury may be mediated by astrocytes. The present work highlights the current evidence on the protective mechanisms of SERMs, such as tamoxifen and raloxifene, in the SNC, and their modulation of astrocytic properties as promising therapeutic targets during brain damage.

  8. Role of perfusion-weighted imaging at 3 T in the histopathological differentiation between astrocytic and oligodendroglial tumors

    International Nuclear Information System (INIS)

    Objective: The differentiation of oligodendroglial tumors from astrocytic tumors is important clinically, because oligodendroglial tumors are more chemosensitive than astrocytic tumors. This study was designed to clarify the usefulness of 3 T MR perfusion imaging (PWI) in the histopathological differentiation between astrocytic and oligodendroglial tumors. This is because there is a growing interest in the diagnostic performance of 3 T MR imaging, which has the advantages of a higher signal-to-noise ratio (SNR) and greater spatial and temporal resolution. Materials and methods: This study retrospectively included 24 consecutive patients with supratentorial, WHO grade II and III astrocytic and oligodendroglial tumors (7 astrocytic, 10 oligoastrocytic, and 7 oligodendroglial tumors) that were newly diagnosed and resected between November 2006 and December 2009 at Hiroshima University Hospital. These patients underwent dynamic susceptibility contrast-enhanced (DSC) PWI relative cerebral blood volume (rCBV) measurements before treatment. Astrocytic tumors were designated as the astrocytic group, and oligoastrocytic and oligodendroglial tumors as the oligodendroglial group. The regions of interest with the maximum rCBV values within the tumors were normalized relative to the contra-lateral white matter (rCBVmax). Results: The average rCBVmax of astrocytic tumors (2.01 ± 0.68) was significantly lower than that of the oligoastrocytic (4.60 ± 1.05) and oligodendroglial tumors (6.17 ± 0.867) (P < 0.0001). A cut-off value of 3.0 allowed to differentiate the oligodendroglial group from the astrocytic group at 100% sensitivity and 87.5% specificity. Conclusion: The rCBVmax values obtained from 3 T MR PWI may be useful as an adjunct to the postoperative histopathological diagnosis of glioma patients.

  9. The impact of dietary isoflavonoids on malignant brain tumors.

    Science.gov (United States)

    Sehm, Tina; Fan, Zheng; Weiss, Ruth; Schwarz, Marc; Engelhorn, Tobias; Hore, Nirjhar; Doerfler, Arnd; Buchfelder, Michael; Eyüpoglu, Iiker Y; Savaskan, Nic E

    2014-08-01

    Poor prognosis and limited therapeutic options render malignant brain tumors one of the most devastating diseases in clinical medicine. Current treatment strategies attempt to expand the therapeutic repertoire through the use of multimodal treatment regimens. It is here that dietary fibers have been recently recognized as a supportive natural therapy in augmenting the body's response to tumor growth. Here, we investigated the impact of isoflavonoids on primary brain tumor cells. First, we treated glioma cell lines and primary astrocytes with various isoflavonoids and phytoestrogens. Cell viability in a dose-dependent manner was measured for biochanin A (BCA), genistein (GST), and secoisolariciresinol diglucoside (SDG). Dose-response action for the different isoflavonoids showed that BCA is highly effective on glioma cells and nontoxic for normal differentiated brain tissues. We further investigated BCA in ex vivo and in vivo experimentations. Organotypic brain slice cultures were performed and treated with BCA. For in vivo experiments, BCA was intraperitoneal injected in tumor-implanted Fisher rats. Tumor size and edema were measured and quantified by magnetic resonance imaging (MRI) scans. In vascular organotypic glioma brain slice cultures (VOGIM) we found that BCA operates antiangiogenic and neuroprotective. In vivo MRI scans demonstrated that administered BCA as a monotherapy was effective in reducing significantly tumor-induced brain edema and showed a trend for prolonged survival. Our results revealed that dietary isoflavonoids, in particular BCA, execute toxicity toward glioma cells, antiangiogenic, and coevally neuroprotective properties, and therefore augment the range of state-of-the-art multimodal treatment approach. PMID:24898306

  10. Negative brain scintigrams in brain tumors

    International Nuclear Information System (INIS)

    With 53 histologically verified and 2 histologically not identified brain tumors, that showed a negative scintigram, it was tried to find reasons for the wrong and negative dropout of these scintigrams. The electroencephalograms and angiograms, that were made simultaneously were taken into consideration with respect to their propositional capability and were compared with the scintigram findings. For the formation of the negative brain scintigrams there could be found no unique cause or causal constellation. The scintigraphic tumor representation is likely based on a complex process. Therefore the reasons for the negativity of the brain scintigrams can be a manifold of causes. An important role plays the vascularisation of the tumor, but not in a sole way. As well the tumor localisation gains some importance; especially in the temporal lobe or in the deeper structures situated tumors can be negative in the scintigram. To hold down the rate of wrong-negative quote in the case of intracranial tumor search, one is advised to continue with an further exposure after 2 to 4 hours besides the usual exposures, unless a sequential scintigraphy was made from the beginning. (orig./MG)

  11. Modulation of Intercellular Calcium Signaling by Melatonin, in Avian and Mammalian Astrocytes, is Brain Region Specific

    OpenAIRE

    Peters, Jennifer L.; Earnest, Barbara J.; Tjalkens, Ronald B.; Cassone, Vincent M.; Zoran, Mark J.

    2005-01-01

    Calcium waves among glial cells impact many central nervous system functions, including neural integration and brain metabolism. Here, we have characterized the modulatory effects of melatonin, a pineal neurohormone that mediates circadian and seasonal processes, on glial calcium waves derived from different brain regions and species. Diencephalic and telencephalic astrocytes, from both chick and mouse brains, expressed melatonin receptor proteins. Further, using the calcium-sensitive dye Flu...

  12. Study of the apparent diffusion coefficient values in the grading of cerebral astrocytic tumors

    International Nuclear Information System (INIS)

    Objective: To investigate the diagnostic value of the apparent diffusion coefficient (ADC) values in the grading of cerebral astrocytic tumors. Methods: Diffusion weighted MR imaging (DWI) was performed for 56 cases of cerebral astrocytic tumors proved pathologically. The ADC and the exponential diffusion coefficient (EDC) values were measured at the tumoral core, per/tumoral edematous region, peritumoral normal-appearance white matter and the contralateral white matter. The rADC and rEDC values of the tumoral core, peritumoral edematous region and peritumoral normal-appearance white matter were calculated. The relationship between the various diffusion coefficient values and tumor grading was analyzed. Results: Fifty six cases of cerebral astrocytic tumors included 2 pilocytic astrocytoma (grade I), 33 astrocytoma (grade II), 8 anaplastic astrocytoma (grade III), 13 glioblastoma multiforme (grade IV). The ADC values of the tumor core of low grade astrocytoma, anaplastic astrocytoma and glioblastoma multiforme were (1.44 ± 0.26) x 10-3, (0.98 ± 0.22) x 10-3 and (0.83 ± 0.15) x 10-3 mm2/s respectively, and the rADC values were (1.91±0.39)%, (1.34±0.33)% and (1.06± 0.20)% respectively. The EDC values were 0.26±0.11, 0.39±0.09 and 0.44±0.07 respectively, and the rEDC values were (0.55±0.20)%, (0.81±0.19)% and (0.98±0.16)% respectively. Significant differences of these values at the tumoral core were seen between different pathological grades of the astrocytic tumors (F=36.189, 31.756, 19.623 and 24.760, P=0.000). The ADC and rADC values of high-grade astrocytic tumors were (0.89 ± 0.19) x 10-3 mm2/s and (1.17±0.28)% respectively, which were lower than those of low-grade astrocytic tumors (t=8.332 and 7.620, P=0.000), while the EDC and rEDC values of high-grade tumors were 0.42±0.08 and (0.91±0.18)% respectively, being higher than those of low-grade turnors (t=-6.082 and -6.776, P=0.000). The accuracy was 89.3% when rADC of 1.52% was set as the

  13. Brain and Spinal Cord Tumors in Adults

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    ... saved articles window. My Saved Articles » My ACS » Brain and Spinal Cord Tumors in Adults Download Printable ... the topics below to get started. What Is Brain/CNS Tumors In Adults? What are adult brain ...

  14. Specific in vivo staining of astrocytes in the whole brain after intravenous injection of sulforhodamine dyes.

    Directory of Open Access Journals (Sweden)

    Florence Appaix

    Full Text Available Fluorescent staining of astrocytes without damaging or interfering with normal brain functions is essential for intravital microscopy studies. Current methods involved either transgenic mice or local intracerebral injection of sulforhodamine 101. Transgenic rat models rarely exist, and in mice, a backcross with GFAP transgenic mice may be difficult. Local injections of fluorescent dyes are invasive. Here, we propose a non-invasive, specific and ubiquitous method to stain astrocytes in vivo. This method is based on iv injection of sulforhodamine dyes and is applicable on rats and mice from postnatal age to adulthood. The astrocytes staining obtained after iv injection was maintained for nearly half a day and showed no adverse reaction on astrocytic calcium signals or electroencephalographic recordings in vivo. The high contrast of the staining facilitates the image processing and allows to quantify 3D morphological parameters of the astrocytes and to characterize their network. Our method may become a reference for in vivo staining of the whole astrocytes population in animal models of neurological disorders.

  15. Monitoring Radiographic Brain Tumor Progression

    Directory of Open Access Journals (Sweden)

    John H. Sampson

    2011-03-01

    Full Text Available Determining radiographic progression in primary malignant brain tumors has posed a significant challenge to the neuroncology community. Glioblastoma multiforme (GBM, WHO Grade IV through its inherent heterogeneous enhancement, growth patterns, and irregular nature has been difficult to assess for progression. Our ability to detect tumor progression radiographically remains inadequate. Despite the advanced imaging techniques, detecting tumor progression continues to be a clinical challenge. Here we review the different criteria used to detect tumor progression, and highlight the inherent challenges with detection of progression.

  16. Expression of iron-related genes in human brain and brain tumors

    Directory of Open Access Journals (Sweden)

    Britton Robert S

    2009-04-01

    Full Text Available Abstract Background Defective iron homeostasis may be involved in the development of some diseases within the central nervous system. Although the expression of genes involved in normal iron balance has been intensively studied in other tissues, little is known about their expression in the brain. We investigated the mRNA levels of hepcidin (HAMP, HFE, neogenin (NEO1, transferrin receptor 1 (TFRC, transferrin receptor 2 (TFR2, and hemojuvelin (HFE2 in normal human brain, brain tumors, and astrocytoma cell lines. The specimens included 5 normal brain tissue samples, 4 meningiomas, one medulloblastoma, 3 oligodendrocytic gliomas, 2 oligoastrocytic gliomas, 8 astrocytic gliomas, and 3 astrocytoma cell lines. Results Except for hemojuvelin, all genes studied had detectable levels of mRNA. In most tumor types, the pattern of gene expression was diverse. Notable findings include high expression of transferrin receptor 1 in the hippocampus and medulla oblongata compared to other brain regions, low expression of HFE in normal brain with elevated HFE expression in meningiomas, and absence of hepcidin mRNA in astrocytoma cell lines despite expression in normal brain and tumor specimens. Conclusion These results indicate that several iron-related genes are expressed in normal brain, and that their expression may be dysregulated in brain tumors.

  17. Insensitivity of astrocytes to interleukin 10 signaling following peripheral immune challenge results in prolonged microglial activation in the aged brain.

    Science.gov (United States)

    Norden, Diana M; Trojanowski, Paige J; Walker, Frederick R; Godbout, Jonathan P

    2016-08-01

    Immune-activated microglia from aged mice produce exaggerated levels of cytokines. Despite high levels of microglial interleukin (IL)-10 in the aged brain, neuroinflammation was prolonged and associated with depressive-like deficits. Because astrocytes respond to IL-10 and, in turn, attenuate microglial activation, we investigated if astrocyte-mediated resolution of microglial activation was impaired with age. Here, aged astrocytes had a dysfunctional profile with higher glial fibrillary acidic protein, lower glutamate transporter expression, and significant cytoskeletal re-arrangement. Moreover, aged astrocytes had reduced expression of growth factors and IL-10 receptor-1 (IL-10R1). After in vivo lipopolysaccharide immune challenge, aged astrocytes had a molecular signature associated with reduced responsiveness to IL-10. This IL-10 insensitivity of aged astrocytes resulted in a failure to induce IL-10R1 and transforming growth factor β and resolve microglial activation. In addition, adult astrocytes reduced microglial activation when co-cultured ex vivo, whereas aged astrocytes did not. Consistent with the aging studies, IL-10R(KO) astrocytes did not augment transforming growth factor β after immune challenge and failed to resolve microglial activation. Collectively, a major cytokine-regulatory loop between activated microglia and astrocytes is impaired in the aged brain. PMID:27318131

  18. MRI of high-grade astrocytic tumors: early appearance and evolution

    International Nuclear Information System (INIS)

    The clinical management and prognosis of patients with diffusely infiltrating astrocytomas are dependent on neuropathological grading of the tumors. The characteristics of MR images of high-grade astrocytic tumors are well known, but the early MRI appearance and the MRI evolution of high-grade astrocytic tumors have rarely been examined. We retrospectively reviewed MR images obtained from 4 months to 3 years and 3 months before admission, as well as MR images on admission, for five patients with pathologically proven high-grade astrocytic tumors (two glioblastomas and three anaplastic astrocytomas). In two patients, neoplastic lesions were not detectable on initial MRI, even retrospectively. In the remaining three patients, however, hyperintense areas with little or no mass effect were demonstrated on T2-weighted imaging. These lesions were misinterpreted as non-neoplastic processes, such as ischemic lesion or infarction, or demyelinating processes. All tumors showed gadolinium enhancement on admission, that emerged from the previously existing hyperintense areas on T2-weighted images without gadolinium enhancement, except for one de novo glioblastoma. Development of a small central cyst without gadolinium enhancement was demonstrated in one case before the emergence of an enhancing area. (orig.)

  19. Heterogeneity in expression of functional ionotropic glutamate and GABA receptors in astrocytes across brain regions: insights from the thalamus

    OpenAIRE

    Höft, Simon; Griemsmann, Stephanie; Seifert, Gerald; Steinhäuser, Christian

    2014-01-01

    Astrocytes may express ionotropic glutamate and gamma-aminobutyric acid (GABA) receptors, which allow them to sense and to respond to neuronal activity. However, so far the properties of astrocytes have been studied only in a few brain regions. Here, we provide the first detailed receptor analysis of astrocytes in the murine ventrobasal thalamus and compare the properties with those in other regions. To improve voltage-clamp control and avoid indirect effects during drug applications, freshly...

  20. Spectrum of pediatric brain tumors in India: A multi-institutional study

    Directory of Open Access Journals (Sweden)

    Ayushi Jain

    2011-01-01

    Full Text Available Background : Till date there is no published multi-institutional data regarding the epidemiological profile of pediatric brain tumors in India. Aim : The present retrospective study analyses the histological spectrum of pediatric age group brain tumors in seven tertiary care hospitals in India. Material and Methods : Data regarding frequencies of various primary brain tumors (diagnosed according to the World Health Organization (WHO classification, in 3936 pediatric patients (<18 yrs of age, was collected from seven tertiary care hospitals in India.Results : The most common primary pediatric brain tumors were astrocytic tumors (34.7%, followed by medulloblastoma and supratentorial primitive neuro-ectodermal tumors (22.4%, craniopharyngiomas (10.2% and ependymal tumors (9.8%. The most common astrocytic tumor was pilocytic astrocytoma. In comparison to adults, oligodendrogliomas and lymphomas were rare in children. Conclusions : Our study is the first such report on the histological spectrum of brain tumors in children in India. Except for a slightly higher frequency of craniopharyngiomas, the histological profile of pediatric brain tumors in India is similar to that reported in the Western literature.

  1. Extra-axial brain tumors.

    Science.gov (United States)

    Rapalino, Otto; Smirniotopoulos, James G

    2016-01-01

    Extra-axial brain tumors are the most common adult intracranial neoplasms and encompass a broad spectrum of pathologic subtypes. Meningiomas are the most common extra-axial brain tumor (approximately one-third of all intracranial neoplasms) and typically present as slowly growing dural-based masses. Benign meningiomas are very common, and may occasionally be difficult to differentiate from more aggressive subtypes (i.e., atypical or malignant varieties) or other dural-based masses with more aggressive biologic behavior (e.g., hemangiopericytoma or dural-based metastases). Many neoplasms that typically affect the brain parenchyma (intra-axial), such as gliomas, may also present with primary or secondary extra-axial involvement. This chapter provides a general and concise overview of the common types of extra-axial tumors and their typical imaging features. PMID:27432671

  2. Brain tumors; Hirntumoren

    Energy Technology Data Exchange (ETDEWEB)

    Langen, K.J. [Forschungszentrum Juelich (Germany). Inst. fuer Neurowissenschaften und Biophysik; Stoffels, G. [Duesseldorf Univ. (Germany). C. und O. Vogt Inst. fuer Hirnforschung

    2007-09-15

    Magnetic Resonance Tomography (MRT) is the method of choice for the diagnostics of cerebral gliomas, but the differentiation of tumour tissue from unspecific tissue changes is limited. Positron emission tomography (PET) and Single-Photon-Emission-Computed Tomography (SPECT) may offer relevant additional information which allows for a more accurate diagnostics in unclear situations. Especially, radiolabeled amino acids offer a better delineation of cerebral gliomas which allows an improved guidance of biopsy, planning of surgery and radiation therapy. Furthermore, amino acid imaging appears to be useful to differentiate tumor recurrence from unspecific posttherapeutic tissue, to predict the prognosis especially in low grade gliomas and to monitor the metabolic response during tumor therapy. (orig.)

  3. Repair of astrocytes, blood vessels, and myelin in the injured brain: possible roles of blood monocytes

    OpenAIRE

    Jeong, Hey-Kyeong; Ji, Kyung-min; Kim, Jun; Jou, Ilo; Joe, Eun-hye

    2013-01-01

    Inflammation in injured tissue has both repair functions and cytotoxic consequences. However, the issue of whether brain inflammation has a repair function has received little attention. Previously, we demonstrated monocyte infiltration and death of neurons and resident microglia in LPS-injected brains (Glia. 2007. 55:1577; Glia. 2008. 56:1039). Here, we found that astrocytes, oligodendrocytes, myelin, and endothelial cells disappeared in the damage core within 1–3 d and then re-appeared at 7...

  4. Brain tumors imaging

    International Nuclear Information System (INIS)

    At the beginning of the illness, we should use an anatomical technique for brain exploration (CT scan or MRI) to see the boundaries of the lesion before the diagnostic biopsy. After treatment (chemotherapy and/or radiotherapy and/or surgery), the evolution of the lesion can be observed with functional techniques (SPECT Thallium or MIBI or PET scan). (author)

  5. Detection of mouse endogenous type B astrocytes migrating towards brain lesions

    Directory of Open Access Journals (Sweden)

    Gema Elvira

    2015-01-01

    Full Text Available Neuroblasts represent the predominant migrating cell type in the adult mouse brain. There are, however, increasing evidences of migration of other neural precursors. This work aims at identifying in vivo endogenous early neural precursors, different from neuroblasts, able to migrate in response to brain injuries. The monoclonal antibody Nilo1, which unequivocally identifies type B astrocytes and embryonic radial glia, was coupled to magnetic glyconanoparticles (mGNPs. Here we show that Nilo1–mGNPs in combination with magnetic resonance imaging in living mice allowed the in vivo identification of endogenous type B astrocytes at their niche, as well as their migration to the lesion site in response to glioblastoma, demyelination, cryolesion or mechanical injuries. In addition, Nilo1+ adult radial glia-like structures were identified at the lesion site a few hours after damage. For all damage models used, type B astrocyte migration was fast and orderly. Identification of Nilo1+ cells surrounding an induced glioblastoma was also possible after intraperitoneal injection of the antibody. This opens up the possibility of an early identification of the initial damage site(s after brain insults, by the migration of type B astrocytes.

  6. Uptake of dimercaptosuccinate-coated magnetic iron oxide nanoparticles by cultured brain astrocytes

    Science.gov (United States)

    Geppert, Mark; Hohnholt, Michaela C.; Thiel, Karsten; Nürnberger, Sylvia; Grunwald, Ingo; Rezwan, Kurosch; Dringen, Ralf

    2011-04-01

    Magnetic iron oxide nanoparticles (Fe-NP) are currently considered for various diagnostic and therapeutic applications in the brain. However, little is known on the accumulation and biocompatibility of such particles in brain cells. We have synthesized and characterized dimercaptosuccinic acid (DMSA) coated Fe-NP and have investigated their uptake by cultured brain astrocytes. DMSA-coated Fe-NP that were dispersed in physiological medium had an average hydrodynamic diameter of about 60 nm. Incubation of cultured astrocytes with these Fe-NP caused a time- and concentration-dependent accumulation of cellular iron, but did not lead within 6 h to any cell toxicity. After 4 h of incubation with 100-4000 µM iron supplied as Fe-NP, the cellular iron content reached levels between 200 and 2000 nmol mg - 1 protein. The cellular iron content after exposure of astrocytes to Fe-NP at 4 °C was drastically lowered compared to cells that had been incubated at 37 °C. Electron microscopy revealed the presence of Fe-NP-containing vesicles in cells that were incubated with Fe-NP at 37 °C, but not in cells exposed to the nanoparticles at 4 °C. These data demonstrate that cultured astrocytes efficiently take up DMSA-coated Fe-NP in a process that appears to be saturable and strongly depends on the incubation temperature.

  7. Uptake of dimercaptosuccinate-coated magnetic iron oxide nanoparticles by cultured brain astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Geppert, Mark; Hohnholt, Michaela C; Dringen, Ralf [Center for Biomolecular Interactions Bremen, University of Bremen, PO Box 330440, D-28334 Bremen (Germany); Thiel, Karsten; Grunwald, Ingo [Fraunhofer Institute for Manufacturing Technology and Advanced Materials, Wiener Strasse 12, D-28359 Bremen (Germany); Nuernberger, Sylvia [Department of Traumatology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Rezwan, Kurosch, E-mail: ralf.dringen@uni-bremen.de [Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, D-28359 Bremen (Germany)

    2011-04-08

    Magnetic iron oxide nanoparticles (Fe-NP) are currently considered for various diagnostic and therapeutic applications in the brain. However, little is known on the accumulation and biocompatibility of such particles in brain cells. We have synthesized and characterized dimercaptosuccinic acid (DMSA) coated Fe-NP and have investigated their uptake by cultured brain astrocytes. DMSA-coated Fe-NP that were dispersed in physiological medium had an average hydrodynamic diameter of about 60 nm. Incubation of cultured astrocytes with these Fe-NP caused a time- and concentration-dependent accumulation of cellular iron, but did not lead within 6 h to any cell toxicity. After 4 h of incubation with 100-4000 {mu}M iron supplied as Fe-NP, the cellular iron content reached levels between 200 and 2000 nmol mg{sup -1} protein. The cellular iron content after exposure of astrocytes to Fe-NP at 4 deg. C was drastically lowered compared to cells that had been incubated at 37 deg. C. Electron microscopy revealed the presence of Fe-NP-containing vesicles in cells that were incubated with Fe-NP at 37 deg. C, but not in cells exposed to the nanoparticles at 4 deg. C. These data demonstrate that cultured astrocytes efficiently take up DMSA-coated Fe-NP in a process that appears to be saturable and strongly depends on the incubation temperature.

  8. Uptake of dimercaptosuccinate-coated magnetic iron oxide nanoparticles by cultured brain astrocytes

    International Nuclear Information System (INIS)

    Magnetic iron oxide nanoparticles (Fe-NP) are currently considered for various diagnostic and therapeutic applications in the brain. However, little is known on the accumulation and biocompatibility of such particles in brain cells. We have synthesized and characterized dimercaptosuccinic acid (DMSA) coated Fe-NP and have investigated their uptake by cultured brain astrocytes. DMSA-coated Fe-NP that were dispersed in physiological medium had an average hydrodynamic diameter of about 60 nm. Incubation of cultured astrocytes with these Fe-NP caused a time- and concentration-dependent accumulation of cellular iron, but did not lead within 6 h to any cell toxicity. After 4 h of incubation with 100-4000 μM iron supplied as Fe-NP, the cellular iron content reached levels between 200 and 2000 nmol mg-1 protein. The cellular iron content after exposure of astrocytes to Fe-NP at 4 deg. C was drastically lowered compared to cells that had been incubated at 37 deg. C. Electron microscopy revealed the presence of Fe-NP-containing vesicles in cells that were incubated with Fe-NP at 37 deg. C, but not in cells exposed to the nanoparticles at 4 deg. C. These data demonstrate that cultured astrocytes efficiently take up DMSA-coated Fe-NP in a process that appears to be saturable and strongly depends on the incubation temperature.

  9. Astrocyte sodium signaling and neuro-metabolic coupling in the brain.

    Science.gov (United States)

    Rose, C R; Chatton, J-Y

    2016-05-26

    At tripartite synapses, astrocytes undergo calcium signaling in response to release of neurotransmitters and this calcium signaling has been proposed to play a critical role in neuron-glia interaction. Recent work has now firmly established that, in addition, neuronal activity also evokes sodium transients in astrocytes, which can be local or global depending on the number of activated synapses and the duration of activity. Furthermore, astrocyte sodium signals can be transmitted to adjacent cells through gap junctions and following release of gliotransmitters. A main pathway for activity-related sodium influx into astrocytes is via high-affinity sodium-dependent glutamate transporters. Astrocyte sodium signals differ in many respects from the well-described glial calcium signals both in terms of their temporal as well as spatial distribution. There are no known buffering systems for sodium ions, nor is there store-mediated release of sodium. Sodium signals thus seem to represent rather direct and unbiased indicators of the site and strength of neuronal inputs. As such they have an immediate influence on the activity of sodium-dependent transporters which may even reverse in response to sodium signaling, as has been shown for GABA transporters for example. Furthermore, recovery from sodium transients through Na(+)/K(+)-ATPase requires a measurable amount of ATP, resulting in an activation of glial metabolism. In this review, we present basic principles of sodium regulation and the current state of knowledge concerning the occurrence and properties of activity-related sodium transients in astrocytes. We then discuss different aspects of the relationship between sodium changes in astrocytes and neuro-metabolic coupling, putting forward the idea that indeed sodium might serve as a new type of intracellular ion signal playing an important role in neuron-glia interaction and neuro-metabolic coupling in the healthy and diseased brain. PMID:25791228

  10. STRUCTURAL AND FUNCTIONAL HETEROGENEITY OF ASTROCYTES IN THE BRAIN: ROLE IN NEURODEGENERATION AND NEUROINFLAMMATION

    Directory of Open Access Journals (Sweden)

    A. V. Morgun

    2014-01-01

    Full Text Available The review covers the current concepts on structural and functional heterogeneity of brain astrocytes that serve for numerous (pathophysiological processes in the central nervous system. Astrocytes from various subpopulations demonstrate different sensitivity to the action of pathogenic factors, varied behaviors in reactive processes and within the local immune response. Key functions of astrocytes like neurogenesis, neuron-astroglia metabolic coupling, glial control of local blood flow greatly depend on the origin and characteristics of astroglial cells. Changes at the initial stages of neurodegeneration or in neurodevelopmental disorders are associated with significant alterations in astroglial structural and functional properties, thus suggesting new approaches to therapeutic strategies implementing astroglia-expressing molecules and targets for effective

  11. Protective and Antioxidant Effects of a Chalconoid from Pulicaria incisa on Brain Astrocytes

    Directory of Open Access Journals (Sweden)

    Anat Elmann

    2013-01-01

    Full Text Available Oxidative stress is involved in the pathogenesis of neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. Astrocytes, the most abundant glial cells in the brain, protect neurons from reactive oxygen species (ROS and provide them with trophic support, such as glial-derived neurotrophic factor (GDNF. Thus, any damage to astrocytes will affect neuronal survival. In the present study, by activity-guided fractionation, we have purified from the desert plant Pulicaria incisa two protective compounds and determined their structures by spectroscopic methods. The compounds were found to be new chalcones—pulichalconoid B and pulichalconoid C. This is the first study to characterize the antioxidant and protective effects of these compounds in any biological system. Using primary cultures of astrocytes, we have found that pulichalconoid B attenuated the accumulation of ROS following treatment of these cells with hydrogen peroxide by 89% and prevented 89% of the H2O2-induced death of astrocytes. Pulichalconoid B exhibited an antioxidant effect both in vitro and in the cellular antioxidant assay in astrocytes and microglial cells. Pulichalconoid B also caused a fourfold increase in GDNF transcription in these cells. Thus, this chalcone deserves further studies in order to evaluate if beneficial therapeutic effect exists.

  12. More Complete Removal of Malignant Brain Tumors by Fluorescence-Guided Surgery

    Science.gov (United States)

    2016-05-13

    Benign Neoplasms, Brain; Brain Cancer; Brain Neoplasms, Benign; Brain Neoplasms, Malignant; Brain Tumor, Primary; Brain Tumor, Recurrent; Brain Tumors; Intracranial Neoplasms; Neoplasms, Brain; Neoplasms, Intracranial; Primary Brain Neoplasms; Primary Malignant Brain Neoplasms; Primary Malignant Brain Tumors; Gliomas; Glioblastoma

  13. Brain angiogenesis: Mechanism and Therapeutic Intervention in Brain Tumors

    OpenAIRE

    Kim, Woo-Young; Lee, Ho-Young

    2009-01-01

    Formation of new blood vessels is required for growth and metastasis of all solid tumors. New blood vessels are established in tumors mainly through angiogenesis. Brain tumors in particular are highly angiogenic. Therefore, interventions designed to prevent angiogenesis may be effective at controlling brain tumors. Indeed, many recent findings from preclinical and clinical studies of antiangiogenic therapy for brain tumors showed that it is a promising approach to managing this deadly disease...

  14. Evaluating brain tumors with SPECT

    International Nuclear Information System (INIS)

    The evaluation of cerebral blood flow and metabolism using functional imaging in combination with morphological imaging by CT and MRI has recently been attracting attention in neuroradiological diagnosis of brain tumor. This report assesses the clinical usefulness of SPECT for brain tumor. Because 201TlCl SPECT is useful in determining the degree of brain tumor malignancy and clearly reflects tumor metabolism after radiochemotherapy, it is capable of determining therapeutic outcomes earlier than MRI. To increase the diagnostic performance of 201TlCl SPECT, time-course accumulation dynamics were investigated using early and delayed imaging. Three-dimensional SPECT imaging using N-isopropyl-p[123I]-iodoamphetamine (123I-IMP) is a new diagnostic method that not only visually evaluates the lesion but also quantifies the expansion volume of the hypoperfusion area associated with the lesion. Development of functional imaging may lead to a new therapeutic method by providing clinical images that more faithfully reproduce the pathological state. (author)

  15. Fiber tracking for brain tumor

    International Nuclear Information System (INIS)

    The purpose of this study was to validate an innovative scanning method for patients diagnosed with brain tumors. Using a 1.5 Tesla whole body magnetic resonance (MR) imager, 23 patients with brain tumors were scanned. The recorded data points of the diffusion-tensor imaging (DTI) sequences were 128 x 37 with the parallel imaging technique. The parallel imaging technique was equivalent to a true resolution of 128 x 74. The scan parameters were repetition time (TR)=6000, echo time (TE)=88, 6 averaging with a b-value of 800 s/mm2. The total scan time for DTI was 4 minutes and 24 seconds. DTI scans and subsequent fiber tracking were successfully applied in all cases. All fiber tracts on the contralesional side were visualized in the expected locations. Fiber tracts on the lesional side had varying degrees of displacement, disruption, or a combination of displacement and disruption due to the tumor. Tract disruption resulted from direct tumor involvement, compression upon the tract, and vasogenic edema surrounding the tumor. This DTI method using a parallel imaging technique allows for clinically feasible fiber tracking that can be incorporated into a routine MR examination. (author)

  16. Brain and Spinal Tumors: Hope through Research

    Science.gov (United States)

    ... and worsen as the tumor grows. The most obvious sign of a brain tumor in infants is ... blood flow, antidepressants to treat anxiety or ease depression that might occur following a tumor diagnosis, and ...

  17. Human T-cell lymphotropic virus type 1-infected T lymphocytes impair catabolism and uptake of glutamate by astrocytes via Tax-1 and tumor necrosis factor alpha.

    Science.gov (United States)

    Szymocha, R; Akaoka, H; Dutuit, M; Malcus, C; Didier-Bazes, M; Belin, M F; Giraudon, P

    2000-07-01

    Human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of a chronic progressive myelopathy called tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM). In this disease, lesions of the central nervous system (CNS) are associated with perivascular infiltration by lymphocytes. We and others have hypothesized that these T lymphocytes infiltrating the CNS may play a prominent role in TSP/HAM. Here, we show that transient contact of human or rat astrocytes with T lymphocytes chronically infected by HTLV-1 impairs some of the major functions of brain astrocytes. Uptake of extracellular glutamate by astrocytes was significantly decreased after transient contact with infected T cells, while the expression of the glial transporters GLAST and GLT-1 was decreased. In two-compartment cultures avoiding direct cell-to-cell contact, similar results were obtained, suggesting possible involvement of soluble factors, such as cytokines and the viral protein Tax-1. Recombinant Tax-1 and tumor necrosis factor alpha (TNF-alpha) decreased glutamate uptake by astrocytes. Tax-1 probably acts by inducing TNF-alpha, as the effect of Tax-1 was abolished by anti-TNF-alpha antibody. The expression of glutamate-catabolizing enzymes in astrocytes was increased for glutamine synthetase and decreased for glutamate dehydrogenase, the magnitudes of these effects being correlated with the level of Tax-1 transcripts. In conclusion, Tax-1 and cytokines produced by HTLV-1-infected T cells impair the ability of astrocytes to manage the steady-state level of glutamate, which in turn may affect neuronal and oligodendrocytic functions and survival. PMID:10864655

  18. Aerobic glycolysis during brain activation: adrenergic regulation and influence of norepinephrine on astrocytic metabolism.

    Science.gov (United States)

    Dienel, Gerald A; Cruz, Nancy F

    2016-07-01

    Aerobic glycolysis occurs during brain activation and is characterized by preferential up-regulation of glucose utilization compared with oxygen consumption even though oxygen level and delivery are adequate. Aerobic glycolysis is a widespread phenomenon that underlies energetics of diverse brain activities, such as alerting, sensory processing, cognition, memory, and pathophysiological conditions, but specific cellular functions fulfilled by aerobic glycolysis are poorly understood. Evaluation of evidence derived from different disciplines reveals that aerobic glycolysis is a complex, regulated phenomenon that is prevented by propranolol, a non-specific β-adrenoceptor antagonist. The metabolic pathways that contribute to excess utilization of glucose compared with oxygen include glycolysis, the pentose phosphate shunt pathway, the malate-aspartate shuttle, and astrocytic glycogen turnover. Increased lactate production by unidentified cells, and lactate dispersal from activated cells and lactate release from the brain, both facilitated by astrocytes, are major factors underlying aerobic glycolysis in subjects with low blood lactate levels. Astrocyte-neuron lactate shuttling with local oxidation is minor. Blockade of aerobic glycolysis by propranolol implicates adrenergic regulatory processes including adrenal release of epinephrine, signaling to brain via the vagus nerve, and increased norepinephrine release from the locus coeruleus. Norepinephrine has a powerful influence on astrocytic metabolism and glycogen turnover that can stimulate carbohydrate utilization more than oxygen consumption, whereas β-receptor blockade 're-balances' the stoichiometry of oxygen-glucose or -carbohydrate metabolism by suppressing glucose and glycogen utilization more than oxygen consumption. This conceptual framework may be helpful for design of future studies to elucidate functional roles of preferential non-oxidative glucose utilization and glycogen turnover during brain

  19. The impact of dietary isoflavonoids on malignant brain tumors

    International Nuclear Information System (INIS)

    Poor prognosis and limited therapeutic options render malignant brain tumors one of the most devastating diseases in clinical medicine. Current treatment strategies attempt to expand the therapeutic repertoire through the use of multimodal treatment regimens. It is here that dietary fibers have been recently recognized as a supportive natural therapy in augmenting the body's response to tumor growth. Here, we investigated the impact of isoflavonoids on primary brain tumor cells. First, we treated glioma cell lines and primary astrocytes with various isoflavonoids and phytoestrogens. Cell viability in a dose-dependent manner was measured for biochanin A (BCA), genistein (GST), and secoisolariciresinol diglucoside (SDG). Dose–response action for the different isoflavonoids showed that BCA is highly effective on glioma cells and nontoxic for normal differentiated brain tissues. We further investigated BCA in ex vivo and in vivo experimentations. Organotypic brain slice cultures were performed and treated with BCA. For in vivo experiments, BCA was intraperitoneal injected in tumor-implanted Fisher rats. Tumor size and edema were measured and quantified by magnetic resonance imaging (MRI) scans. In vascular organotypic glioma brain slice cultures (VOGIM) we found that BCA operates antiangiogenic and neuroprotective. In vivo MRI scans demonstrated that administered BCA as a monotherapy was effective in reducing significantly tumor-induced brain edema and showed a trend for prolonged survival. Our results revealed that dietary isoflavonoids, in particular BCA, execute toxicity toward glioma cells, antiangiogenic, and coevally neuroprotective properties, and therefore augment the range of state-of-the-art multimodal treatment approach

  20. Therapy of malignant brain tumors

    International Nuclear Information System (INIS)

    The tumors of the brain claim for a separate position in scientific medicine regarding biology, morphology, features of clinical manifestation, diagnostics and therapy. During the past years due to rapid progress in medical biotechnics the situation of the neuroclinician in front of brain tumors has been dramatically changed. The prerequisites for early and accurate diagnosis as well as for successful treatment also of malignant neoplasms have increased and remarkably improved. At the same time the information necessary for an appropriate pragmatic use of the available cognitive methods and therapeutic means increased along the same scale. These facts necessitate the preparation of publications in which the state of the art is presented in possible completeness, systematic order and proper dis-posability for rational management and therapeutic strategies. The primary aim of the present book is to serve these purposes. With 8 chapters, two of them are indexed for INIS, the collective of competent authors deal on the biology, pathology and immunology of malignant brain tumors of adults and of children including relevant basic and recent data of experimental research; further on the available methods of therapy: neurosurgery, radiology and chemotherapy, the fundamental principals of their efficacy and the differing models of single respective combined application, in comprehensive critical form. 111 figs

  1. Pathological advances in pediatric brain tumors

    Directory of Open Access Journals (Sweden)

    Li-feng WANG

    2015-10-01

    Full Text Available Pediatric brain tumors are the most common solid tumors in children. Compared with brain tumors in adults, pediatric brain tumors have characteristic clinicopathological features and molecular mechanisms. The accurate diagnosis and classification of brain tumors in children is important for patients to have an individualized therapy and to improve the survival rate. With the further study of pediatric brain tumors, there are some new viewpoints on pilocytic astrocytoma (PA, ependymoma, medulloblastoma (MB, atypical teratoid/rhabdoid tumor (AT/RT, etc. In this article, an overview about pathological advances in the common pediatric brain tumors will be shown. DOI: 10.3969/j.issn.1672-6731.2015.10.002

  2. Contribution of gap junctional communication between tumor cells and astroglia to the invasion of the brain parenchyma by human glioblastomas

    Directory of Open Access Journals (Sweden)

    Venance Laurent

    2005-02-01

    Full Text Available Abstract Background Gliomas are "intraparenchymally metastatic" tumors, invading the brain in a non-destructive way that suggests cooperation between glioma cells and their environment. Recent studies using an engineered rodent C6 tumor cell line have pointed to mechanisms of invasion that involved gap junctional communication (GJC, with connexin 43 as a substrate. We explored whether this concept may have clinical relevance by analyzing the participation of GJC in human glioblastoma invasion. Results Three complementary in vitro assays were used: (i seeding on collagen IV, to analyze homocellular interactions between tumor cells (ii co-cultures with astrocytes, to study glioblastoma/astrocytes relationships and (iii implantation into organotypic brain slice cultures, that mimic the three-dimensional parenchymal environment. Carbenoxolone, a potent blocker of GJC, inhibited cell migration in the two latter models. It paradoxically increased it in the first one. These results showed that homocellular interaction between tumor cells supports intercellular adhesion, whereas heterocellular glioblastoma/astrocytes interactions through functional GJC conversely support tumor cell migration. As demonstrated for the rodent cell line, connexin 43 may be responsible for this heterocellular functional coupling. Its levels of expression, high in astrocytes, correlated positively with invasiveness in biopsied tumors. Conclusions our results underscore the potential clinical relevance of the concept put forward by other authors based on experiments with a rodent cell line, that glioblastoma cells use astrocytes as a substrate for their migration by subverting communication through connexin 43-dependent gap junctions.

  3. Analysis of EZH2: micro-RNA network in low and high grade astrocytic tumors.

    Science.gov (United States)

    Sharma, Vikas; Purkait, Suvendu; Takkar, Sonam; Malgulwar, Prit Benny; Kumar, Anupam; Pathak, Pankaj; Suri, Vaishali; Sharma, Mehar C; Suri, Ashish; Kale, Shashank Sharad; Kulshreshtha, Ritu; Sarkar, Chitra

    2016-04-01

    Enhancer of Zeste homologue2 (EZH2) is an epigenetic regulator that functions as oncogene in astrocytic tumors, however, EZH2 regulation remains little studied. In this study, we measured EZH2 levels in low (Gr-II,DA) and high grade (Gr-IV,GBM) astrocytic tumors and found significant increased EZH2 transcript level with grade(median DA-8.5, GBM-28.9).However, a different trend was reflected in protein levels, with GBMs showing high EZH2 LI(median-26.5) compared to DA (median 0.3). This difference in correlation of EZH2 protein and RNA levels suggested post-transcriptional regulation of EZH2, likely mediated by miRNAs. We selected eleven miRNAs that strongly predicted to target EZH2 and measured their expression. Three miRNAs (miR-26a-5p,miR27a-3p and miR-498) showed significant correlation with EZH2 protein, suggesting them as regulators of EZH2, however miR-26a-5p levels decreased with grade. ChIP analyses revealed H3K27me3 modifications in miR-26a promoter suggesting feedback loop between EZH2 and miR26a. We further measured six downstream miRNA targets of EZH2 and found significant downregulation of four (miR-181a/b and 200b/c) in GBM. Interestingly, EZH2 associated miRNAs were predicted to target 25 genes in glioma-pathway, suggesting their role in tumor formation or progression. Collectively, our work suggests EZH2 and its miRNA interactors may serve as promising biomarkers for progression of astrocytic tumors and may offer novel therapeutic strategies. PMID:26746204

  4. Effects of fractionated radiation on the brain vasculature in a murine model: Blood-brain barrier permeability, astrocyte proliferation, and ultrastructural changes

    International Nuclear Information System (INIS)

    Purpose: Radiation therapy of CNS tumors damages the blood-brain barrier (BBB) and normal brain tissue. Our aims were to characterize the short- and long-term effects of fractionated radiotherapy (FRT) on cerebral microvasculature in mice and to investigate the mechanism of change in BBB permeability in mice. Methods and Materials: Intravital microscopy and a cranial window technique were used to measure BBB permeability to fluorescein isothiocyanate (FITC)-dextran and leukocyte endothelial interactions before and after cranial irradiation. Daily doses of 2 Gy were delivered 5 days/week (total, 40 Gy). We immunostained the molecules to detect the expression of glial fibrillary acidic protein and to demonstrate astrocyte activity in brain parenchyma. To relate the permeability changes to endothelial ultrastructural changes, we used electron microscopy. Results: Blood-brain barrier permeability did not increase significantly until 90 days after FRT, at which point it increased continuously until 180 days post-FRT. The number of adherent leukocytes did not increase during the study. The number of astrocytes in the cerebral cortex increased significantly; vesicular activity in endothelial cells increased beginning 90 days after irradiation, and most tight junctions stayed intact, although some were shorter and less dense at 120 and 180 days. Conclusions: The cellular and microvasculature response of the brain to FRT is mediated through astrogliosis and ultrastructural changes, accompanied by an increase in BBB permeability. The response to FRT is delayed as compared with single-dose irradiation treatment, and does not involve leukocyte adhesion. However, FRT induces an increase in the BBB permeability, as in the case of single-dose irradiation

  5. Expression of the Astrocyte Water Channel Aquaporin-4 in the Mouse Brain.

    Science.gov (United States)

    Hubbard, Jacqueline A; Hsu, Mike S; Seldin, Marcus M; Binder, Devin K

    2015-01-01

    Aquaporin-4 (AQP4) is a bidirectional water channel that is found on astrocytes throughout the central nervous system. Expression is particularly high around areas in contact with cerebrospinal fluid, suggesting that AQP4 plays a role in fluid exchange between the cerebrospinal fluid compartments and the brain. Despite its significant role in the brain, the overall spatial and region-specific distribution of AQP4 has yet to be fully characterized. In this study, we used Western blotting and immunohistochemical techniques to characterize AQP4 expression and localization throughout the mouse brain. We observed AQP4 expression throughout the forebrain, subcortical areas, and brainstem. AQP4 protein levels were highest in the cerebellum with lower expression in the cortex and hippocampus. We found that AQP4 immunoreactivity was profuse on glial cells bordering ventricles, blood vessels, and subarachnoid space. Throughout the brain, AQP4 was expressed on astrocytic end-feet surrounding blood vessels but was also heterogeneously expressed in brain tissue parenchyma and neuropil, often with striking laminar specificity. In the cerebellum, we showed that AQP4 colocalized with the proteoglycan brevican, which is synthesized by and expressed on cerebellar astrocytes. Despite the high abundance of AQP4 in the cerebellum, its functional significance has yet to be investigated. Given the known role of AQP4 in synaptic plasticity in the hippocampus, the widespread and region-specific expression pattern of AQP4 suggests involvement not only in fluid balance and ion homeostasis but also local synaptic plasticity and function in distinct brain circuits. PMID:26489685

  6. Glycogen distribution in the microwave-fixed mouse brain reveals heterogeneous astrocytic patterns.

    Science.gov (United States)

    Oe, Yuki; Baba, Otto; Ashida, Hitoshi; Nakamura, Kouichi C; Hirase, Hajime

    2016-09-01

    In the brain, glycogen metabolism has been implied in synaptic plasticity and learning, yet the distribution of this molecule has not been fully described. We investigated cerebral glycogen of the mouse by immunohistochemistry (IHC) using two monoclonal antibodies that have different affinities depending on the glycogen size. The use of focused microwave irradiation yielded well-defined glycogen immunoreactive signals compared with the conventional periodic acid-Schiff method. The IHC signals displayed a punctate distribution localized predominantly in astrocytic processes. Glycogen immunoreactivity (IR) was high in the hippocampus, striatum, cortex, and cerebellar molecular layer, whereas it was low in the white matter and most of the subcortical structures. Additionally, glycogen distribution in the hippocampal CA3-CA1 and striatum had a 'patchy' appearance with glycogen-rich and glycogen-poor astrocytes appearing in alternation. The glycogen patches were more evident with large-molecule glycogen in young adult mice but they were hardly observable in aged mice (1-2 years old). Our results reveal brain region-dependent glycogen accumulation and possibly metabolic heterogeneity of astrocytes. GLIA 2016;64:1532-1545. PMID:27353480

  7. Treatment of Newly Diagnosed and Recurrent Childhood Brain Tumors

    Science.gov (United States)

    ... Treatment of Newly Diagnosed and Recurrent Childhood Brain Tumors The brain is made of different kinds of cells . Childhood ... following: What You Need To Know About™ Brain Tumors Pediatric Brain Tumor Consortium (PBTC) For more childhood cancer information ...

  8. 90K/Mac-2 BP在人脑星形细胞瘤中的表达%Expression of 90K/ Mac-2 BP in human brain astrocytic tumors

    Institute of Scientific and Technical Information of China (English)

    陈鑫; 刘运生; 刘志雄; 杨魁; 李春涛; 曾瑜; 龚璇; 陈敏

    2012-01-01

    目的 分析90K/ Mac-2 BP(Mac-2 binding protein)在人脑星形细胞瘤中的表达.方法 RT-PCR和WB(Western blot)检测90K蛋白在人脑星形细胞瘤以及正常脑组织中的表达.结果 RT-PCR发现90K mRNA在正常脑组织中微量表达,相对表达量为0.116±0.017;而在人脑星形细胞瘤中高表达,相对表达量为0.407±0.151,两组相比有显著差异(t=6.065,P<0.05).低级别组(WHOⅠ-Ⅱ级)与高级别组(WHO Ⅲ-Ⅳ级)相对表达量分别为0.295±0.067和0.516±0.128,两组相比有显著差异(=8.138,P<0.05).WB发现90K蛋白在正常脑组织中微量表达,相对表达量为0.291±0.064,星形细胞瘤中90K蛋白相对表达量为1.163±0.391,两组相比有显著差异(t=15.68,P<0.05).低级别组与高级别组90K蛋白相对表达量分别为0.902±0.272和1.415±0.318,两组相比有显著差异(t=6.539,P<0.05).WB结果表明90K蛋白在星形细胞瘤中的表达情况与RT-PCR结果表明90K mRNA在星形细胞瘤中的表达情况一致.结论 90K在星形细胞瘤中的表达显著升高,高级别星形细胞瘤中的表达较低级别更高,提示90K可能在星形细胞瘤的发生发展过程中发挥了重要作用,90K蛋白可能是星形细胞瘤相关抗原,在今后的免疫治疗中可能作为一种目标抗原.%Objective To investigate the expression of 90K mRNA and protein in human brain astrocytomas. Methods The expression of 90K mRNA in human normal brain tissue and astrocytoma tissue was detected by RT-PCR; The expression of 90K protein in human normal brain tissue and astrocytoma tissue was detected by WB. Results RT-PCR reveal that 90K mRNA was lowly expressed in normal human brain tissues(0. 116 ±0.017). The 90K mRNA expression was significantly higher in astrocytomas (0. 407 ±0. 151 ) than that in normal human brain tissues (t = 6. 065, P < 0. 05) , and significantly higher in high grade astrocytomas ( WHO III-IV) (0.516 ±0. 128) than in low grade(WH0 I-II) (0.295 ±0.067) (t =8. 138, P<0

  9. Histamine in brain development and tumors.

    Science.gov (United States)

    Panula, P; Lintunen, M; Karlstedt, K

    2000-02-01

    Histamine is found in developing mammalian brain in both neurons and mast cells. Under normal conditions, histamine H1 and H2 receptors are found in neural, glial and endothelial cells, and H3 receptors at least on neurons. Experimental brain tumors display both H1 and H2 receptors, and histamine increases permeability in the tumors and in the neighboring areas. Many studies have addressed histaminergic signalling mechanisms in cell lines originating from brain tumors. However, the role of histamine in normal development of brain structures, proliferation and differentiation of neurons and glial cells, and growth of malignant tumors in situ is still poorly understood. PMID:10888266

  10. Non-invasive quantification of brain tumor-induced astrogliosis

    Directory of Open Access Journals (Sweden)

    Baird Andrew

    2011-01-01

    Full Text Available Abstract Background CNS injury including stroke, infection, and tumor growth lead to astrogliosis, a process that involves upregulation of glial fibrillary acidic protein (GFAP in astrocytes. However, the kinetics of astrogliosis that is related to these insults (i.e. tumor is largely unknown. Results Using transgenic mice expressing firefly luciferase under the regulation of the GFAP promoter (GFAP-luc, we developed a model system to monitor astrogliosis upon tumor growth in a rapid, non-invasive manner. A biphasic induction of astrogliosis was observed in our xenograft model in which an early phase of activation of GFAP was associated with inflammatory response followed by a secondary, long-term upregulation of GFAP. These animals reveal GFAP activation with kinetics that is in parallel with tumor growth. Furthermore, a strong correlation between astrogliosis and tumor size was observed. Conclusions Our results suggest that non-invasive, quantitative bioluminescent imaging using GFAP-luc reporter animal is a useful tool to monitor temporal-spatial kinetics of host-mediated astrogliosis that is associated with glioma and metastatic brain tumor growth.

  11. Disruption of the blood-brain interface in neonatal rat neocortex induces a transient expression of metallothionein in reactive astrocytes

    DEFF Research Database (Denmark)

    Penkowa, M; Moos, T

    1995-01-01

    rats were subjected to a localized freeze lesion of the neocortex of the right temporal cortex. This lesion results in a disrupted blood-brain interface, leading to extravasation of plasma proteins. From 16 h, reactive astrocytosis, defined as an increase in the number and size of cells expressing GFAP......Exposure of the adult rat brain parenchyma to zinc induces an increase in the intracerebral expression of the metal-binding protein, metallothionein, which is normally confined to astrocytes, ependymal cells, choroid plexus epithelial cells, and brain endothelial cells. Metallothionein is expressed...... only in diminutive amounts in astrocytes of the neonatal rat brain, which could imply that neonatal rats are devoid of the capacity to detoxify free metals released from a brain wound. In order to examine the influence of a brain injury on the expression of metallothionein in the neonatal brain, PO...

  12. Cancer stem cells and brain tumors

    OpenAIRE

    Pérez Castillo, Ana; Aguilar Morante, Diana; Morales-García, José A.; Dorado, Jorge

    2008-01-01

    Besides the role of normal stem cells in organogenesis, cancer stem cells are thought to be crucial for tumorigenesis. Most current research on human tumors is focused on molecular and cellular analysis of the bulk tumor mass. However, evidence in leukemia and, more recently, in solid tumors suggests that the tumor cell population is heterogeneous. In recent years, several groups have described the existence of a cancer stem cell population in different brain tumors. These neural cancer stem ...

  13. Radiosensitized treatment of malignant brain tumors

    Science.gov (United States)

    Bloznelyte-Plesniene, Laima

    2003-12-01

    Around 12,000 deaths from glioblastoma occurs within the European Community annually. At present, the best available treatment for malignant brain tumors results in a median survival of patients of 15 months despite surgery, radiotherapy, and chemotherapy. The purpose of this paper is to review our results of radiosensitized treatment of malignant brain tumors.

  14. From reverse transcription to human brain tumors

    Directory of Open Access Journals (Sweden)

    Dmitrenko V. V.

    2013-05-01

    Full Text Available Reverse transcriptase from avian myeloblastosis virus (AMV was the subject of the study, from which the investi- gations of the Department of biosynthesis of nucleic acids were started. Production of AMV in grams quantities and isolation of AMV reverse transcriptase were established in the laboratory during the seventies of the past cen- tury and this initiated research on the cDNA synthesis, cloning and investigation of the structure and functions of the eukaryotic genes. Structures of salmon insulin and insulin-like growth factor (IGF family genes and their transcripts were determined during long-term investigations. Results of two modern techniques, microarray-ba- sed hybridization and SAGE, were used for the identification of the genes differentially expressed in astrocytic gliomas and human normal brain. Comparison of SAGE results on the genes overexpressed in glioblastoma with the results of microarray analysis revealed a limited number of common genes. 105 differentially expressed genes, common to both methods, can be included in the list of candidates for the molecular typing of glioblastoma. The first experiments on the classification of glioblastomas based on the data of the 20 genes expression were conducted by using of artificial neural network analysis. The results of these experiments showed that the expression profiles of these genes in 224 glioblastoma samples and 74 normal brain samples could be according to the Koho- nen’s maps. The CHI3L1 and CHI3L2 genes of chitinase-like cartilage protein were revealed among the most overexpressed genes in glioblastoma, which could have prognostic and diagnostic potential. Results of in vitro experiments demonstrated that both proteins, CHI3L1 and CHI3L2, may initiate the phosphorylation of ERK1/ ERK2 and AKT kinases leading to the activation of MAPK/ERK1/2 and PI3K/AKT signaling cascades in human embryonic kidney 293 cells, human glioblastoma U87MG, and U373 cells. The new human cell line

  15. Mutant ubiquitin attenuates interleukin-1β- and tumor necrosis factor-α-induced pro-inflammatory signaling in human astrocytic cells.

    Directory of Open Access Journals (Sweden)

    Kyungsun Choi

    Full Text Available A frameshift mutation of ubiquitin called ubiquitin(+1 (UBB(+1 was found in the aging and Alzheimer's disease brains and thought to be associated with neuronal dysfuction and degeneration. Even though ubiquitylation has been known to regulate vital cellular functions mainly through proteasome-dependent degradation of polyubiquitinated substrates, proteolysis-independent roles of ubiquitylation have emerged as key mechanisms in various signaling cascades. In this study, we have investigated the effect of UBB(+1 on proinflammatory signaling such as interleukin-1β (IL-1β and tumor necrosis factor-α (TNF-α in human astrocytes. Treatment with TNF-α and IL-1β induced expression of CCL2 and CXCL8 by human astrocytic cells; while ectopic expression of UBB(+1 significantly abrogated the proinflammatory cytokine-induced expression of chemokines. Ectopic expression of UBB(+1 suppressed TNF-α- and IL-1β-induced activation of NF-κB and JNK signaling pathway. Furthermore, we have demonstrated that polyubiquitylation of TRAFs and subsequent phosphorylation of TAK1 were significantly inhibited by stable expression of UBB(+1. Collectively, these results suggest that UBB(+1 may affect proinflammatory signaling in the central nervous system via inhibitory mechanisms of ubiquitin-dependent signaling in human astrocytes.

  16. Recent advances in imaging of brain tumors

    OpenAIRE

    D A Sanghvi

    2009-01-01

    The recent advances in brain tumor imaging offer unique anatomical as well as pathophysiological information that provides new insights on brain tumors, directed at facilitating therapeutic decisions and providing information regarding prognosis. This information is presently utilized in clinical practice for initial diagnosis and noninvasive, preoperative grading of tumors, biopsy planning, surgery, and radiation portal planning, as well as, prognostication. The newer advances described in t...

  17. What underlies the diversity of brain tumors?

    OpenAIRE

    Swartling, Fredrik J.; Hede, Sanna-Maria; Weiss, William A.

    2013-01-01

    Glioma and medulloblastoma represent the most commonly occurring malignant brain tumors in adults and in children respectively. Recent genomic and transcriptional approaches present a complex group of diseases, and delineate a number of molecular subgroups within tumors that share a common histopathology. Differences in cells of origin, regional niches, developmental timing and genetic events all contribute to this heterogeneity. In an attempt to recapitulate the diversity of brain tumors, an...

  18. Influence of X-rays on early response gene expression in rat astrocytes and brain tumour cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Vrdoljak, E.; Borchardt, P.E.; Bill, C.A.; Stephens, L.C.; Tofilon, P.J. [Anderson (M.D.) Cancer Center, Houston, TX (United States)

    1994-12-01

    The effects of ionizing radiation on c-fos, c-jun and jun-B mRNA levels were determined in cultures of rat perinatal type 1 astrocytes and two rat brain tumour cell lines, 175A and 9L. In astrocyte cultures X-ray doses as low as 1 Gy induced the expression of c-fos and jun-B but had essentially no effect on c-jun. The maximum increase in expression was found 1 h after irradiation, which then rapidly returned to control levels. These findings suggest that astrocytes may play a role in mediating the radiation response of the central nervous system via X-ray-induced changes in gene expression. In contrast, doses of up to 20 Gy had no effect on c-fos, c-jun and jun-B mRNA levels in the two brain tumour cell lines. In addition, whereas 12-0-tetradecanoylphorbol-13-acetate induced the expression of these genes in astrocytes, it had little or no effect on fos or jun expression in 9L or 175A cells. These results suggest that the signal transduction pathways mediating radiation-induced genes expression may be different in normal astrocytes and brain tumour cells. (author).

  19. Angiotensin II receptor subtypes are coupled with distinct signal-transduction mechanisms in neurons and astrocytes from rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Sumners, C.; Wei Tang; Zelezna, B.; Raizada, M.K. (Univ. of Florida, Gainesville (United States))

    1991-09-01

    Both neurons and astrocytes contain specific receptors for angiotensin II (AII). The authors used selective ligands for the AT{sub 1} and AT{sub 2} types of AII receptors to investigate the expression of functional receptor subtypes in astrocyte cultures and neuron cultures from 1-day-old (neonatal) rat brain. In astrocyte cultures, competition of {sup 125}I-labeled AII ({sup 125}I-AII) specific binding with AT{sub 1} (DuP753) or AT{sub 2} {l brace}PD123177, CGP42112A, (Phe(p-NH{sub 2}){sup 6})AII{r brace} selective receptor ligands revealed a potency series of AII > DuP753 > > > CGP42112A > (Phe(p-NH{sub 2}){sup 6})AII > PD123177. These results suggest a predominance of the AT{sub 1} receptor subtype in neonatal astrocytes. {sup 125}I-AII specific binding to neonate neuronal cultures was reduced 73-84% by 1 {mu} MPD123177, and the residual {sup 125}I-AII specific binding was eliminated by DuP753. The results suggest that astrocyte cultures from neonatal rat brains contain predominantly AT{sub 1} receptors that are coupled to a stimulation of inositophospholipid hydrolysis. In contrast, neuron cultures from neonatal rat brain contain mostly AT{sub 2} receptors that are coupled to a reduction in basal cGMP levels, but a smaller population of AT{sub 1} receptors is also present in these neurons.

  20. Influence of X-rays on early response gene expression in rat astrocytes and brain tumour cell lines

    International Nuclear Information System (INIS)

    The effects of ionizing radiation on c-fos, c-jun and jun-B mRNA levels were determined in cultures of rat perinatal type 1 astrocytes and two rat brain tumour cell lines, 175A and 9L. In astrocyte cultures X-ray doses as low as 1 Gy induced the expression of c-fos and jun-B but had essentially no effect on c-jun. The maximum increase in expression was found 1 h after irradiation, which then rapidly returned to control levels. These findings suggest that astrocytes may play a role in mediating the radiation response of the central nervous system via X-ray-induced changes in gene expression. In contrast, doses of up to 20 Gy had no effect on c-fos, c-jun and jun-B mRNA levels in the two brain tumour cell lines. In addition, whereas 12-0-tetradecanoylphorbol-13-acetate induced the expression of these genes in astrocytes, it had little or no effect on fos or jun expression in 9L or 175A cells. These results suggest that the signal transduction pathways mediating radiation-induced genes expression may be different in normal astrocytes and brain tumour cells. (author)

  1. Acute and chronic glucocorticoid treatments regulate astrocyte-enriched mRNAs in multiple brain regions in vivo

    Directory of Open Access Journals (Sweden)

    BradleyS.Carter

    2013-08-01

    Full Text Available Previous studies have primarily interpreted gene expression regulation by glucocorticoids in the brain in terms of impact on neurons; however, less is known about the corresponding impact of glucocorticoids on glia and specifically astrocytes in vivo. Recent microarray experiments have identified glucocorticoid-sensitive mRNAs in primary astrocyte cell culture, including a number of mRNAs that have reported astrocyte-enriched expression patterns relative to other brain cell types. Here, we have tested whether elevations of glucocorticoids regulate a subset of these mRNAs in vivo following acute and chronic corticosterone exposure in adult mice. Acute corticosterone exposure was achieved by a single injection of 10 mg/kg corticosterone, and tissue samples were harvested two hours post-injection. Chronic corticosterone exposure was achieved by administering 10 mg/mL corticosterone via drinking water for two weeks. Gene expression was then assessed in two brain regions associated with glucocorticoid action (prefrontal cortex and hippocampus by qPCR and by in situ hybridization. The majority of measured mRNAs regulated by glucocorticoids in astrocytes in vitro were similarly regulated by acute and/or chronic glucocorticoid exposure in vivo. In addition, the expression levels for mRNAs regulated in at least one corticosterone exposure condition (acute/chronic demonstrated moderate positive correlation between the two conditions by brain region. In situ hybridization analyses suggest that select mRNAs are regulated by chronic corticosterone exposure specifically in astroctyes based on (1 similar general expression patterns between corticosterone-treated and vehicle-treated animals and (2 similar expression patterns to the pan-astrocyte marker Aldh1l1. Our findings demonstrate that glucocorticoids regulate astrocyte-enriched mRNAs in vivo and suggest that glucocorticoids regulate gene expression in the brain in a cell type-dependent fashion.

  2. BNCT for malignant brain tumors in children

    International Nuclear Information System (INIS)

    BSH-based intra-operative BNCT as an initial treatment underwent in 4 children with malignant brain tumors since 1998. There were 2 glioblastomas, one primitive neuroectodermal tumor (PNET) and one anaplastic ependymoma patient. They included two children under 3-year-old. All GBM patients were died of CSF dissemination without tumor regrowth in the primary site. Another PNET and anaplastic ependymoma patients are still alive without tumor recurrence. We can consider BNCT is optimal treatment modality for malignant brain tumor in children. (author)

  3. Brain tumors in children; Hirntumoren beim Kind

    Energy Technology Data Exchange (ETDEWEB)

    Harting, I.; Seitz, A. [Universitaetsklinikum Heidelberg (Germany). Abt. Neuroradiologie

    2009-06-15

    Brain tumors are common in children; in Germany approximately 400 children are diagnosed every year. In the posterior fossa, cerebellar neoplasms outnumber brainstem gliomas. In contrast to their rarity in adults, brainstem gliomas are not uncommon in children. Supratentorial tumors can be subdivided by location into neoplasms of the cerebral hemispheres, suprasellar and pineal tumors. Astrocytoma is the most common pediatric brain tumor followed by medulloblastoma, ependymoma and craniopharyngeoma. The combination of imaging morphology, tumor localisation and patient age at manifestation form the basis of the neuroradiological differential diagnosis. (orig.)

  4. Brain tumors in patients primarly treated psychiatrically

    Directory of Open Access Journals (Sweden)

    Ignjatović-Ristić Dragana

    2011-01-01

    Full Text Available Introduction. Psychiatric symptoms are not rare manifestations of brain tumors. Brain tumors presented by symptoms of raised intracranial pressure, focal neurological signs, or convulsions are usually first seen by the neurologist or less frequently by the neurosurgeon in routine diagnostic procedures. On the other hand, when psychiatric symptoms are the first manifestation in “neurologically silent” brain tumors, the patients are sent to the psychiatrist for the treatment of psychiatric symptoms and brain tumors are left misdiagnosed for a long period of time. Case Report. We presented three patients with the diagnosed brain tumor where psychiatrist had been the first specialist to be consulted. In all three cases neurological examination was generally unremarkable with no focal signs or features of raised intracranial pressure. CT scan demonstrated right insular tumor in a female patient with obsessive-compulsive disorder (OCD; right parietal temporal tumor in a patient with delusions and depression and left frontal tumor in a patient with history of alcohol dependency. Conclusion. Psychiatric symptoms/disorders in patients with brain tumors are not specific enough and can have the same clinical presentation as the genuine psychiatric disorder. Therefore, we emphasize the consideration of neuroimaging in patients with abrupt beginning of psychiatric symptoms, in those with a change in mental status, or when headaches suddenly appear or in cases of treatment resistant psychiatric disorders regardless the lack of neurological symptoms.

  5. TTF-1 may not be a Reliable Marker for Differentiating Metastasis from Brain Tumors

    Directory of Open Access Journals (Sweden)

    Betül ÜNAL

    2014-09-01

    Full Text Available Objective: TTF-1 is widely used as an immunohistochemical marker of lung and thyroid tumors. However, TTF-1 expression has been described in tumors from other sites. The presence of TTF-1 expression in primary brain tumors is largely unclear and has not been clearly specified yet. We characterized expression of two TTF-1 clones in primary brain tumors with relevance to tumor types and grades. Material and Method: We studied immunohistochemistry with tissue micro-array, using both clones (8G7G3/1 and SPT24 in 45 primary brain tumors of different types and grades. Our cases consisted of 1 grade I, 7 grade II, 4 grade III, 20 grade IV astrocytic tumors; 9 meningiomas, 2 oligodendrogliomas, 1 schwannoma and 1 medulloblastoma. Results: We have found TTF-1 nuclear staining using the SPT24 clone in 4 cases (3 cases were grade IV and 1 was grade III. Focal and weak staining was seen in three cases and moderate-strong and diffuse staining was seen in one case. All the tumors were negative with clone 8G7G3/1. Clone SPT24 was more sensitive but less specific. Conclusion: TTF-1 can also be expressed in primary brain tumors, particularly grade III to IV tumors. TTF-1 expression was a rare finding in previous studies, however strong and diffuse staining was not observed until today. We think that TTF-1 nuclear expression in high-grade astrocytic tumors cannot rule out primaries even when diffuse and strong staining. Clinical and pathological parameters should be evaluated together.

  6. Brain tumors: Special characters for research and banking

    OpenAIRE

    Majid Kheirollahi; Sepideh Dashti; Zahra Khalaj; Fatemeh Nazemroaia; Parvin Mahzouni

    2015-01-01

    A brain tumor is an intracranial neoplasm within the brain or in the central spinal canal. Primary malignant brain tumors affect about 200,000 people worldwide every year. Brain cells have special characters. Due to the specific properties of brain tumors, including epidemiology, growth, and division, investigation of brain tumors and the interpretation of results is not simple. Research to identify the genetic alterations of human tumors improves our knowledge of tumor biology, genetic inter...

  7. The presence of serum alters the properties of iron oxide nanoparticles and lowers their accumulation by cultured brain astrocytes

    International Nuclear Information System (INIS)

    Iron oxide nanoparticles (IONPs) are considered for various diagnostic and therapeutic applications. Such particles are able to cross the blood–brain barrier and are taken up into brain cells. To test whether serum components affect the properties of IONPs and/or their uptake into brain cells, we have incubated dimercaptosuccinate-coated magnetic IONPs without and with fetal calf serum (FCS) and have exposed cultured brain astrocytes with IONPs in the absence or presence of FCS. Incubation with FCS caused a concentration-dependent increase in the average hydrodynamic diameter of the particles and of their zeta-potential. In the presence of 10 % FCS, the diameter of the IONPs increased from 57 ± 2 to 107 ± 6 nm and the zeta-potential of the particles from −22 ± 5 to −9 ± 1 mV. FCS affected also strongly the uptake of IONPs by cultured astrocytes. The efficient time- and temperature-dependent cellular accumulation of IONPs was lowered with increasing concentration of FCS by up to 90 %. In addition, in the absence of serum, endocytosis inhibitors did not alter the IONP accumulation by astrocytes, while chlorpromazine or wortmannin lowered significantly the accumulation of IONPs in the presence of FCS, suggesting that clathrin-mediated endocytosis and macropinocytosis are involved in astrocytic IONP uptake from serum-containing medium. These data demonstrate that the presence of FCS strongly affects the properties of IONPs as well as their accumulation by cultured brain cells.

  8. The presence of serum alters the properties of iron oxide nanoparticles and lowers their accumulation by cultured brain astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Geppert, Mark; Petters, Charlotte [University of Bremen, Centre for Biomolecular Interactions Bremen (Germany); Thiel, Karsten [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (Germany); Dringen, Ralf, E-mail: ralf.dringen@uni-bremen.de [University of Bremen, Centre for Biomolecular Interactions Bremen (Germany)

    2013-01-15

    Iron oxide nanoparticles (IONPs) are considered for various diagnostic and therapeutic applications. Such particles are able to cross the blood-brain barrier and are taken up into brain cells. To test whether serum components affect the properties of IONPs and/or their uptake into brain cells, we have incubated dimercaptosuccinate-coated magnetic IONPs without and with fetal calf serum (FCS) and have exposed cultured brain astrocytes with IONPs in the absence or presence of FCS. Incubation with FCS caused a concentration-dependent increase in the average hydrodynamic diameter of the particles and of their zeta-potential. In the presence of 10 % FCS, the diameter of the IONPs increased from 57 {+-} 2 to 107 {+-} 6 nm and the zeta-potential of the particles from -22 {+-} 5 to -9 {+-} 1 mV. FCS affected also strongly the uptake of IONPs by cultured astrocytes. The efficient time- and temperature-dependent cellular accumulation of IONPs was lowered with increasing concentration of FCS by up to 90 %. In addition, in the absence of serum, endocytosis inhibitors did not alter the IONP accumulation by astrocytes, while chlorpromazine or wortmannin lowered significantly the accumulation of IONPs in the presence of FCS, suggesting that clathrin-mediated endocytosis and macropinocytosis are involved in astrocytic IONP uptake from serum-containing medium. These data demonstrate that the presence of FCS strongly affects the properties of IONPs as well as their accumulation by cultured brain cells.

  9. Correlation of the indices of susceptibility weighted imaging and perfusion imaging with the expression of microvessel density and vascular endothelial growth factor in astrocytic tumor

    Institute of Scientific and Technical Information of China (English)

    韩彤

    2014-01-01

    Objective To detect the correlation of the expression of microvessel density(MVD)and vascular endothelial growth factor(VEGF)with the semi-quantivative indices of susceptibility weighted imaging(SWI)and perfusion imaging(PI)in astrocytic tumor.Methods SWI and PI were performed in 98 patients with varing grades of astrocytic tumors.According to the World Health Organization(WHO)classification of central nervous system tumors and grading criteria:8 cases of pilocytic astrocytoma(gradeⅠ,1

  10. A Case Report of Brain Stem Tumor

    Directory of Open Access Journals (Sweden)

    R Nazari

    2004-07-01

    Full Text Available Background: Brain and spinal cord tumors are the most frequent neoplasms after leukemia in children. Brain stem glioma is responsible for 10-20% of brain tumors in this group and often found in pons presenting with cerebellar signs, cranial nerve palsies, pyramidal signs and eventually increased intracranial pressure Case Report: In this article we reported an 11 year old girl affected with brain stem tumor with signs of headache, dizziness, vomiting and ataxia. Strabismus due to palsy of sixth cranial nerve, and dysarthria was observed. Conclusion: Children complaining of vomiting, headache and dizziness for a long time must be assessed for brain tumor in posterior fossa that sometimes may lead to increased intracranial pressure. An exact neurological examination can be worth guide to diagnosis.

  11. The pivotal role of astrocytes in an in-vitro stroke model of the blood-brain barrier

    Directory of Open Access Journals (Sweden)

    Winfried Neuhaus

    2014-10-01

    Full Text Available Stabilization of the blood-brain barrier during and after stroke can lead to less adverse outcome. For elucidation of underlying mechanisms and development of novel therapeutic strategies validated in-vitro disease models of the blood-brain barrier could be very helpful. To mimic in-vitro stroke conditions we have established a blood-brain barrier in-vitro model based on mouse cell line cerebEND and applied oxygen/glucose deprivation (OGD. The role of astrocytes in this disease model was investigated by using cell line C6. Transwell studies pointed out that addition of astrocytes during OGD increased the barrier damage significantly in comparison to the endothelial monoculture shown by changes of transendothelial electrical resistance as well as fluorescein permeability data. Analysis on mRNA and protein levels by qPCR, western blotting and immunofluorescence microscopy of tight junction molecules claudin-3,-5,-12, occludin and ZO-1 revealed that their regulation and localisation is associated with the functional barrier breakdown. Furthermore, soluble factors of astrocytes, OGD and their combination were able to induce changes of functionality and expression of ABC-transporters Abcb1a (P-gp, Abcg2 (bcrp and Abcc4 (mrp4. Moreover, the expression of proteases (matrixmetalloproteinases MMP-2, MMP-3 and MMP-9 and t-PA as well as of their endogenous inhibitors (TIMP-1, TIMP-3, PAI-1 was altered by astrocyte factors and OGD which resulted in significant changes of total MMP and t-PA activity. Morphological rearrangements induced by OGD and treatment with astrocyte factors were confirmed at a nanometer scale using atomic force microscopy. In conclusion, astrocytes play a major role in blood-brain barrier breakdown during OGD in vitro.

  12. Vasodilation by in vivo activation of astrocyte endfeet via two-photon calcium uncaging as a strategy to prevent brain ischemia

    Science.gov (United States)

    Chen, Yuanxin; Mancuso, James; Zhao, Zhen; Li, Xuping; Cheng, Jie; Roman, Gustavo; Wong, Stephen T. C.

    2013-12-01

    Decreased cerebral blood flow causes brain ischemia and plays an important role in the pathophysiology of many neurodegenerative diseases, including Alzheimer's disease and vascular dementia. In this study, we photomodulated astrocytes in the live animal by a combination of two-photon calcium uncaging in the astrocyte endfoot and in vivo imaging of neurovasculature and astrocytes by intravital two-photon microscopy after labeling with cell type specific fluorescent dyes. Our study demonstrates that photomodulation at the endfoot of a single astrocyte led to a 25% increase in the diameter of a neighboring arteriole, which is a crucial factor regulating cerebral microcirculation in downstream capillaries. Two-photon uncaging in the astrocyte soma or endfoot near veins does not show the same effect on microcirculation. These experimental results suggest that infrared photomodulation on astrocyte endfeet may be a strategy to increase cerebral local microcirculation and thus prevent brain ischemia.

  13. Asymptomatic brain tumor detected at brain check-up

    Energy Technology Data Exchange (ETDEWEB)

    Onizuka, Masanari; Suyama, Kazuhiko; Shibayama, Akira; Hiura, Tsuyoshi; Horie, Nobutaka; Miyazaki, Hisaya [Sankoukai Miyazaki Hospital, Isahaya, Nagasaki (Japan)

    2001-09-01

    Brain check-up was performed in 4000 healthy subjects who underwent medical and radiological examinations for possible brain diseases in our hospital from April 1996 to March 2000. Magnetic resonance imaging revealed 11 brain tumors which consisted of six meningiomas, three pituitary adenomas, one astrocytoma, and one epidermoid cyst. The detection rate of incidental brain tumor in our hospital was 0.3%. Nine patients underwent surgery, with one case of morbidity due to postoperative transient oculomotor nerve paresis. The widespread use of brain check-up may increasingly detect asymptomatic brain tumors. Surgical indications for such lesions remain unclear, and the strategy for treatment should be determined with consideration of the patient's wishes. (author)

  14. Frequent loss of heterozygosity and altered expression of the candidate tumor suppressor gene 'FAT' in human astrocytic tumors

    International Nuclear Information System (INIS)

    We had earlier used the comparison of RAPD (Random Amplification of Polymorphic DNA) DNA fingerprinting profiles of tumor and corresponding normal DNA to identify genetic alterations in primary human glial tumors. This has the advantage that DNA fingerprinting identifies the genetic alterations in a manner not biased for locus. In this study we used RAPD-PCR to identify novel genomic alterations in the astrocytic tumors of WHO grade II (Low Grade Diffuse Astrocytoma) and WHO Grade IV (Glioblastoma Multiforme). Loss of heterozygosity (LOH) of the altered region was studied by microsatellite and Single Nucleotide Polymorphism (SNP) markers. Expression study of the gene identified at the altered locus was done by semi-quantitative reverse-transcriptase-PCR (RT-PCR). Bands consistently altered in the RAPD profile of tumor DNA in a significant proportion of tumors were identified. One such 500 bp band, that was absent in the RAPD profile of 33% (4/12) of the grade II astrocytic tumors, was selected for further study. Its sequence corresponded with a region of FAT, a putative tumor suppressor gene initially identified in Drosophila. Fifty percent of a set of 40 tumors, both grade II and IV, were shown to have Loss of Heterozygosity (LOH) at this locus by microsatellite (intragenic) and by SNP markers. Semi-quantitative RT-PCR showed low FAT mRNA levels in a major subset of tumors. These results point to a role of the FAT in astrocytic tumorigenesis and demonstrate the use of RAPD analysis in identifying specific alterations in astrocytic tumors

  15. Brain tumor stem cell dancing

    Directory of Open Access Journals (Sweden)

    Giuseppina Bozzuto

    2014-09-01

    Full Text Available Background. Issues regarding cancer stem cell (CSC movement are important in neurosphere biology as cell-cell or cell-environment interactions may have significant impacts on CSC differentiation and contribute to the heterogeneity of the neurosphere. Aims. Despite the growing body of literature data on the biology of brain tumor stem cells, floating CSC-derived neurospheres have been scarcely characterized from a morphological and ultrastructural point of view. Results. Here we report a morphological and ultrastructural characterization performed by live imaging and scanning electron microscopy. Glioblastoma multiforme (GBM CSC-derived neurospheres are heterogeneous and are constituted by cells, morphologically different, capable of forming highly dynamic structures. These dynamic structures are regulated by not serendipitous cell-cell interactions, and they synchronously pulsate following a cyclic course made of "fast" and "slow" alternate phases. Autocrine/paracrine non canonical Wnt signalling appears to be correlated with the association status of neurospheres. Conclusions. The results obtained suggest that GBM CSCs can behave both as independents cells and as "social" cells, highly interactive with other members of its species, giving rise to a sort of "multicellular organism".

  16. Proteome-wide lysine acetylation in cortical astrocytes and alterations that occur during infection with brain parasite Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Anne Bouchut

    Full Text Available Lysine acetylation is a reversible post-translational modification (PTM that has been detected on thousands of proteins in nearly all cellular compartments. The role of this widespread PTM has yet to be fully elucidated, but can impact protein localization, interactions, activity, and stability. Here we present the first proteome-wide survey of lysine acetylation in cortical astrocytes, a subtype of glia that is a component of the blood-brain barrier and a key regulator of neuronal function and plasticity. We identified 529 lysine acetylation sites across 304 proteins found in multiple cellular compartments that largely function in RNA processing/transcription, metabolism, chromatin biology, and translation. Two hundred and seventy-seven of the acetylated lysines we identified on 186 proteins have not been reported previously in any other cell type. We also mapped an acetylome of astrocytes infected with the brain parasite, Toxoplasma gondii. It has been shown that infection with T. gondii modulates host cell gene expression, including several lysine acetyltransferase (KAT and deacetylase (KDAC genes, suggesting that the host acetylome may also be altered during infection. In the T. gondii-infected astrocytes, we identified 34 proteins exhibiting a level of acetylation >2-fold and 24 with a level of acetylation <2-fold relative to uninfected astrocytes. Our study documents the first acetylome map for cortical astrocytes, uncovers novel lysine acetylation sites, and demonstrates that T. gondii infection produces an altered acetylome.

  17. The multifaceted responses of primary human astrocytes and brain microvascular endothelial cells to the Lyme disease spirochete, Borrelia burgdorferi

    Directory of Open Access Journals (Sweden)

    Catherine A. Brissette

    2013-08-01

    Full Text Available The vector-borne pathogen, Borrelia burgdorferi, causes a multi-system disorder including neurological complications. These neurological disorders, collectively termed neuroborreliosis, can occur in up to 15% of untreated patients. The neurological symptoms are probably a result of a glial-driven, host inflammatory response to the bacterium. However, the specific contributions of individual glial and other support cell types to the pathogenesis of neuroborreliosis are relatively unexplored. The goal of this project was to characterize specific astrocyte and endothelial cell responses to B. burgdorferi. Primary human astrocytes and primary HBMEC (human brain microvascular endothelial cells were incubated with B. burgdorferi over a 72-h period and the transcriptional responses to the bacterium were analyzed by real-time PCR arrays. There was a robust increase in several surveyed chemokine and related genes, including IL (interleukin-8, for both primary astrocytes and HBMEC. Array results were confirmed with individual sets of PCR primers. The production of specific chemokines by both astrocytes and HBMEC in response to B. burgdorferi, including IL-8, CXCL-1, and CXCL-10, were confirmed by ELISA. These results demonstrate that primary astrocytes and HBMEC respond to virulent B. burgdorferi by producing a number of chemokines. These data suggest that infiltrating phagocytic cells, particularly neutrophils, attracted by chemokines expressed at the BBB (blood–brain barrier may be important contributors to the early inflammatory events associated with neuroborreliosis.

  18. Culturing of PC12 Cells, Neuronal Cells, Astrocytes Cultures and Brain Slices in an Open Microfluidic System

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Bakmand, Tanya; Rømer Sørensen, Ane;

    culturing PC12 cells, neuronal cells, astrocytes cultures and brain slices. The microfluidic system provides efficient nutrient delivery, waste removal, access to oxygen, fine control over the neurochemical environment and access to modern microscopy. Additionally, the setup consists of an in vitro...

  19. Cognitive deficits in patients with brain tumor

    Institute of Scientific and Technical Information of China (English)

    SHEN Chao; BAO Wei-min; YANG Bo-jie; XIE Rong; CAO Xiao-yun; LUAN Shi-hai; MAO Ying

    2012-01-01

    Objective To discuss the present status and progress of clinical research on the cognitive effects caused by different types of brain tumors and common treatments.Data sources The data used in this review were mainly from PubMed articles published in English from 1990 to Febuary 2012.Research terms were "cognitive deficits" or "cognitive dysfunction".Study selection Articals including any information about brain tumor related cognitive deficits were selected.Results It is widely accepted that brain tumors and related treatments can impair cognitive function across manydomains,and can impact on patients' quality of life.Tumor localization,lateralization,surgery,drugs,radiotherapy and chemotherapy are all thought to be important factors in this process.However,some conflicting findings regarding brain tumor-related cognitive deficits have been reported.It can be difficult to determine the mechanism of these treatments,such as chemotherapy,antibiotics,antiepileptics,and steroids.Future research is needed to clarify these potential treatment effects.Conclusions Cognitive function is important for patients with brain tumor.Much more focus has been paid on this field.It should be regarded as an important prognostic index for the patients with brain tumor,and neuropsychological tests should be used in regular examinations.

  20. Copper Metabolism of Astrocytes

    OpenAIRE

    Ralf Dringen; Scheiber, Ivo F.; Julian FB Mercer

    2013-01-01

    This short review will summarize the current knowledge on the uptake, storage, and export of copper ions by astrocytes and will address the potential roles of astrocytes in copper homeostasis in the normal and diseased brain. Astrocytes in culture efficiently accumulate copper by processes that include both the copper transporter Ctr1 and Ctr1-independent mechanisms. Exposure of astrocytes to copper induces an increase in cellular glutathione (GSH) content as well as synthesis of metallothion...

  1. Brain Tumor Epidemiology Consortium Membership Information

    Science.gov (United States)

    BTEC welcomes new members interested in the development of multi-center, inter-disciplinary collaborations that will lead to a better understanding of the etiology, outcomes and prevention of all brain tumors.

  2. Neurogenic effect of VEGF is related to increase of astrocytes transdifferentiation into new mature neurons in rat brains after stroke.

    Science.gov (United States)

    Shen, Shu-Wen; Duan, Chun-Ling; Chen, Xian-Hua; Wang, Yong-Quan; Sun, Xiao; Zhang, Qiu-Wan; Cui, Hui-Ru; Sun, Feng-Yan

    2016-09-01

    To study the cellular mechanism of vascular endothelial growth factor (VEGF)-enhanced neurogenesis in ischemic brain injury, we used middle cerebral artery occlusion (MCAO) model to induce transient focal ischemic brain injury. The results showed that ischemic injury significantly increased glial fibrillary acidic protein immunopositive (GFAP(+)) and nestin(+) cells in ipsilateral striatum 3 days following MCAO. Most GFAP(+) cells colocalized with nestin (GFAP(+)-nestin(+)), Pax6 (GFAP(+)-Pax6(+)), or Olig2 (GFAP(+)-Olig2(+)). VEGF further increased GFAP(+)-nestin(+) and GFAP(+)-Pax6(+) cells, and decreased GFAP(+)-Olig2(+) cells. We used striatal injection of GFAP targeted enhanced green fluorescence protein (pGfa2-EGFP) vectors combined with multiple immunofluorescent staining to trace the neural fates of EGFP-expressing (GFP(+)) reactive astrocytes. The results showed that MCAO-induced striatal reactive astrocytes differentiated into neural stem cells (GFP(+)-nestin(+) cells) at 3 days after MCAO, immature (GFP(+)-Tuj-1(+) cells) at 1 week and mature neurons (GFP(+)-MAP-2(+) or GFP(+)-NeuN(+) cells) at 2 weeks. VEGF increased GFP(+)-NeuN(+) and BrdU(+)-MAP-2(+) newborn neurons after MCAO. Fluorocitrate, an astrocytic inhibitor, significantly decreased GFAP and nestin expression in ischemic brains, and also reduced VEGF-enhanced neurogenic effects. This study is the first time to report that VEGF-mediated increase of newly generated neurons is dependent on the presence of reactive astrocytes. The results also illustrate cellular mechanism of VEGF-enhanced neural repair and functional plasticity in the brains after ischemic injury. We concluded that neurogenic effect of VEGF is related to increase of striatal astrocytes transdifferentiation into new mature neurons, which should be very important for the reconstruction of neurovascular units/networks in non-neurogenic regions of the mammalian brain. PMID:26603138

  3. Role of astrocytic leptin receptor subtypes on leptin permeation across hCMEC/D3 human brain endothelial cells

    OpenAIRE

    Hsuchou, Hung; Kastin, Abba J; Tu, Hong; Abbott, N Joan; Couraud, Pierre-Olivier; Pan, Weihong

    2010-01-01

    Astrocytic leptin receptors (ObR) can be upregulated in conditions such as adult-onset obesity. To determine whether the levels and subtypes of astrocytic ObR modulate leptin transport, we co-cultured hCMEC/D3 human brain endothelial cells and C6 astrocytoma cells in the Transwell system, and tested leptin permeation from apical to basolateral chambers. In comparison with hCMEC alone, co-culture of C6 cells reduced the permeability of paracellular markers and leptin. Unexpectedly, ObRb overex...

  4. Significance of the astrocyte domain organization for qualitative information structuring in the brain

    OpenAIRE

    Bernhard J Mitterauer

    2010-01-01

    Astrocytes, the dominant glial cell type, modulate synaptic information transmission. Each astrocyte is organized in non-overlapping domains. Here, a formally based model of the possible significance of astrocyte domain organization is proposed. It is hypothesized that each astrocyte contacting n neurons with m synapses via its processes generates dynamic domains of synaptic interactions based on qualitative criteria so that it exerts a structuring of neuronal information processing. The form...

  5. Similarity on neural stem cells and brain tumor stem cells in transgenic brain tumor mouse models

    OpenAIRE

    Qiao, Guanqun; Li, Qingquan; Peng, Gang; Ma, Jun; Fan, Hongwei; Li, Yingbin

    2013-01-01

    Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are still unclear. In this study, we used stable doxycycline-inducible transgenic mouse brain tumor models (c-myc+/SV40Tag+/Tet-on+) to explore the malignant trans-formation potential of neural stem cells by observing the differences of neural stem cells and brain tumor stem cells in the tumor models. Results showed that chromosome instability occurred in brain t...

  6. Astrocyte-targeted expression of IL-6 protects the CNS against a focal brain injury

    DEFF Research Database (Denmark)

    Penkowa, Milena; Giralt, Mercedes; Lago, Natalia;

    2003-01-01

    study demonstrated that transgenic IL-6 production significantly increased wound healing following the cryolesion. Thus, at 20 days postlesion (dpl) the GFAP-IL6 mice showed almost complete wound healing compared to litter mate nontransgenic controls. It seems likely that a reduced inflammatory response...... in the long term could be responsible for this IL-6-related effect. Thus, while in the acute phase following cryolesion (1-6 dpl) the recruitment of macrophages and T lymphocytes was higher in GFAP-IL6 mice, at 10-20 dpl it was significantly reduced compared to controls. Reactive astrogliosis was...... as to the transgenic IL-6-induced increase of the antioxidant, neuroprotective proteins metallothionein-I + II. These results indicate that although in the brain the chronic astrocyte-targeted expression of IL-6 spontaneously induces an inflammatory response causing significant damage, during an...

  7. Permeability imaging in pediatric brain tumors

    OpenAIRE

    Lam, Sandi; Lin, Yimo; Warnke, Peter C.

    2014-01-01

    While traditional computed tomography (CT) and magnetic resonance (MR) imaging illustrate the structural morphology of brain pathology, newer, dynamic imaging techniques are able to show the movement of contrast throughout the brain parenchyma and across the blood-brain barrier (BBB). These data, in combination with pharmacokinetic models, can be used to investigate BBB permeability, which has wide-ranging applications in the diagnosis and management of central nervous system (CNS) tumors in ...

  8. Similarity on neural stem cells and brain tumor stem cells in transgenic brain tumor mouse models

    Institute of Scientific and Technical Information of China (English)

    Guanqun Qiao; Qingquan Li; Gang Peng; Jun Ma; Hongwei Fan; Yingbin Li

    2013-01-01

    Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are stil unclear. In this study, we used stable doxycycline-inducible transgenic mouse brain tumor models (c-myc+/SV40Tag+/Tet-on+) to explore the malignant trans-formation potential of neural stem cells by observing the differences of neural stem cel s and brain tumor stem cells in the tumor models. Results showed that chromosome instability occurred in brain tumor stem cells. The numbers of cytolysosomes and autophagosomes in brain tumor stem cells and induced neural stem cel s were lower and the proliferative activity was obviously stronger than that in normal neural stem cells. Normal neural stem cells could differentiate into glial fibril ary acidic protein-positive and microtubule associated protein-2-positive cells, which were also negative for nestin. However, glial fibril ary acidic protein/nestin, microtubule associated protein-2/nestin, and glial fibril ary acidic protein/microtubule associated protein-2 double-positive cells were found in induced neural stem cells and brain tumor stem cel s. Results indicate that induced neural stem cells are similar to brain tumor stem cells, and are possibly the source of brain tumor stem cells.

  9. Fluorescent Nanoparticle Uptake for Brain Tumor Visualization

    Directory of Open Access Journals (Sweden)

    Rachel Tréhin

    2006-04-01

    Full Text Available Accurate delineation of tumor margins is vital to the successful surgical resection of brain tumors. We have previously developed a multimodal nanoparticle CLIO-Cy5.5, which is detectable by both magnetic resonance imaging and fluorescence, to assist in intraoperatively visualizing tumor boundaries. Here we examined the accuracy of tumor margin determination of orthotopic tumors implanted in hosts with differing immune responses to the tumor. Using a nonuser-based signal intensity method applied to fluorescent micrographs of 9L gliosarcoma green fluorescent protein (GFP tumors, mean overestimations of 2 and 24 µm were obtained using Cy5.5 fluorescence, compared to the true tumor margin determined by GFP fluorescence, in nude mice and rats, respectively. To resolve which cells internalized the nanoparticle and to quantitate degree of uptake, tumors were disaggregated and cells were analyzed by flow cytometry and fluorescence microscopy. Nanoparticle uptake was seen in both CD11b+ cells (representing activated microglia and macrophages and tumor cells in both animal models by both methods. CD11b+ cells were predominantly found at the tumor margin in both hosts, but were more pronounced at the margin in the rat model. Additional metastatic (CT26 colon and primary (Gli36 glioma brain tumor models likewise demonstrated that the nanoparticle was internalized both by tumor cells and by host cells. Together, these observations suggest that fluorescent nanoparticles provide an accurate method of tumor margin estimation based on a combination of tumor cell and host cell uptake for primary and metastatic tumors in animal model systems and offer potential for clinical translation.

  10. Bleomycin treatment of brain tumors: an evaluation

    DEFF Research Database (Denmark)

    Linnert, Mette; Gehl, Julie

    2009-01-01

    Bleomycin has been used in the treatment of brain tumors for over 30 years. Currently, we are evaluating electrochemotherapy (the use of electric pulses to enhance uptake of bleomycin) for patients with secondary brain tumors. We, therefore, reviewed the literature with specific reference...... to the tolerability and toxicity of bleomycin. Using the keywords 'brain' and 'bleomycin', a database search without date restriction was performed and over 500 articles were found. Twenty-five articles were used for this study based on relevance determined by: (i) clinical studies, (ii) use of bleomycin, and (iii...

  11. Proton MRS imaging in pediatric brain tumors.

    Science.gov (United States)

    Zarifi, Maria; Tzika, A Aria

    2016-06-01

    Magnetic resonance (MR) techniques offer a noninvasive, non-irradiating yet sensitive approach to diagnosing and monitoring pediatric brain tumors. Proton MR spectroscopy (MRS), as an adjunct to MRI, is being more widely applied to monitor the metabolic aspects of brain cancer. In vivo MRS biomarkers represent a promising advance and may influence treatment choice at both initial diagnosis and follow-up, given the inherent difficulties of sequential biopsies to monitor therapeutic response. When combined with anatomical or other types of imaging, MRS provides unique information regarding biochemistry in inoperable brain tumors and can complement neuropathological data, guide biopsies and enhance insight into therapeutic options. The combination of noninvasively acquired prognostic information and the high-resolution anatomical imaging provided by conventional MRI is expected to surpass molecular analysis and DNA microarray gene profiling, both of which, although promising, depend on invasive biopsy. This review focuses on recent data in the field of MRS in children with brain tumors. PMID:27233788

  12. Multiparametric MR assessment of pediatric brain tumors

    International Nuclear Information System (INIS)

    MR assessment of pediatric brain tumors has expanded to include physiologic information related to cellular metabolites, hemodynamic and diffusion parameters. The purpose of this study was to investigate the relationship between MR and proton MR spectroscopic imaging in children with primary brain tumors. Twenty-one patients (mean age 9 years) with histologically verified brain tumors underwent conventional MR imaging, hemodynamic MR imaging (HMRI) and proton MR spectroscopic imaging (MRSI). Fourteen patients also had diffusion-weighted MR imaging (DWMRI). Metabolic indices including choline-containing compounds (Cho), total creatine (tCr) and lipids/lactate (L) were derived by proton MRSI, relative cerebral blood volume (rCBV) by HMRI, and apparent tissue water diffusion coefficients (ADC) by DWMRI. Variables were examined by linear regression and correlation as well as by ANOVA. Cho (suggestive of tumor cellularity and proliferative activity) correlated positively with rCBV, while the relationship between Cho and ADC (suggestive of cellular density) was inverse (P<0.001). The relationship between rCBV and ADC was also inverse (P=0.004). Cho and lipids (suggestive of necrosis and/or apoptosis) were not significantly correlated (P=0.51). A positive relationship was found between lipids and ADC (P=0.002). The relationships between Cho, rCBV, ADC and lipids signify that tumor physiology is influenced by the tumor's physical and chemical environment. Normalized Cho and lipids distinguished high-grade from low-grade tumors (P<0.05). Multiparametric MR imaging using MRSI, HMRI and DWMRI enhances assessment of brain tumors in children and improves our understanding of tumor physiology while promising to distinguish higher- from lower-malignancy tumors, a distinction that is particularly clinically important among inoperable tumors. (orig.)

  13. Differential tumor necrosis factor alpha expression by astrocytes from experimental allergic encephalomyelitis-susceptible and -resistant rat strains

    OpenAIRE

    1991-01-01

    There is evidence that the cytokine tumor necrosis factor alpha (TNF- alpha) contributes to the pathogenesis of neurological autoimmune diseases such as multiple sclerosis (MS) and experimental allergic encephalomyelitis (EAE). TNF-alpha exerts damaging effects on oligodendrocytes, the myelin-producing cell of the central nervous system (CNS), and myelin itself. We have recently demonstrated TNF- alpha expression from astrocytes induced by lipopolysaccharide (LPS), interferon gamma (IFN-gamma...

  14. Tumor necrosis factor receptor superfamily member 9 is upregulated in the endothelium and tumor cells in melanoma brain metastasis

    Directory of Open Access Journals (Sweden)

    Patrick N Harter

    2014-12-01

    Full Text Available Aim: The cytokine receptor tumor necrosis factor receptor superfamily member 9 (TNFRSF9 is mainly considered to be a co-stimulatory activation marker in hematopoietic cells. Several preclinical models have shown a dramatic beneficial effect of treatment approaches targeting TNFRSF9 with agonistic antibodies. However, preliminary clinical phase I/II studies were stopped after the occurrence of several severe deleterious side effects. In a previous study, it was demonstrated that TNFRSF9 was strongly expressed by reactive astrocytes in primary central nervous system (CNS tumors, but was largely absent from tumor or inflammatory cells. The aim of the present study was to address the cellular source of TNFRSF9 expression in the setting of human melanoma brain metastasis, a highly immunogenic tumor with a prominent tropism to the CNS. Methods: Melanoma brain metastasis was analyzed in a cohort of 78 patients by immunohistochemistry for TNFRSF9 and its expression was correlated with clinicopathological parameters including sex, age, survival, tumor size, number of tumor spots, and BRAF V600E expression status. Results: Tumor necrosis factor receptor superfamily member 9 was frequently expressed independently on both melanoma and endothelial cells. In addition, TNFRSF9 was also present on smooth muscle cells of larger vessels and on a subset of lymphomonocytic tumor infiltrates. No association between TNFRSF9 expression and patient survival or other clinicopathological parameters was seen. Of note, several cases showed a gradual increase in TNFRSF9 expression on tumor cells with increasing distance from blood vessels, an observation that might be linked to hypoxia-driven TNFRSF9 expression in tumor cells. Conclusion: The findings indicate that the cellular source of TNFRSF9 in melanoma brain metastasis largely exceeds the lymphomonocytic pool, and therefore further careful (re- assessment of potential TNFRSF9 functions in cell types other than

  15. P2X7 receptor activation in rat brain cultured astrocytes increases the biosynthetic release of cysteinyl leukotrienes.

    Science.gov (United States)

    Ballerini, P; Ciccarelli, R; Caciagli, F; Rathbone, M P; Werstiuk, E S; Traversa, U; Buccella, S; Giuliani, P; Jang, S; Nargi, E; Visini, D; Santavenere, C; Di Iorio, P

    2005-01-01

    Astrocytes have been recognized as important elements in controlling inflammatory as well as immune processes in the central nervous system (CNS). Recently, glial cells have been shown to produce cysteinyl leukotrienes (CysLTs) which are known lipid mediators of inflammation and whose extracellular concentrations rise under different pathological conditions in the brain. In the same conditions also extracellular concentrations of ATP dramatically increase reaching levels able to activate P2X7 ionotropic receptors for which an emerging role in neuroinflammation and neurodegeneration has been claimed. RTPCR analysis showed that primary cultures of rat brain astrocytes express P2X7 receptors. Application of the selective P2X7 agonist benzoyl benzoly ATP (BzATP) markedly increased [Ca2+]i which was mediated by a calcium influx from the extracellular milieu. The P2X7 antagonist, oATP, suppressed the BzATP-induced calcium increase. Consistent with the evidence that increased calcium levels activate the leukotriene biosynthetic pathway, challenge of astrocytes with either the calcium ionophore A23187 or BzATP significantly increased CysLT production and the cell pre-treatment with EGTA abolished these effects. Again the P2X7 antagonist prevented the BzATP-mediated CysLT efflux, whereas the astrocyte pretreatment with MK-571, a CysLT1 receptor antagonist, was ineffective. The astrocyte pre-treatment with a cocktail of inhibitors of ATP binding cassette (ABC) proteins reduced the BzATP-mediated CysLT production confirming that ABC transporters are involved in the release of CysLTs. The astrocyte P2X7- evoked rise of CysLT efflux was abolished in the presence of MK-886, an inhibitor of 5-lipoxygenase activating protein (FLAP) whose expression, along with that of 5-lipoxygenase (5-LO) was reported by Northern Blot analysis. The stimulation of P2X7 induced an up-regulation of FLAPmRNA that was reduced by the antagonist oATP. These data suggest that in rat brain cultured

  16. Recent developments in brain tumor predisposing syndromes.

    Science.gov (United States)

    Johansson, Gunnar; Andersson, Ulrika; Melin, Beatrice

    2016-01-01

    The etiologies of brain tumors are in the most cases unknown, but improvements in genetics and DNA screening have helped to identify a wide range of brain tumor predisposition disorders. In this review we are discussing some of the most common predisposition disorders, namely: neurofibromatosis type 1 and 2, schwannomatosis, rhabdoid tumor predisposition disorder, nevoid basal cell carcinoma syndrome (Gorlin), tuberous sclerosis complex, von Hippel-Lindau, Li-Fraumeni and Turcot syndromes. Recent findings from the GLIOGENE collaboration and the newly identified glioma causing gene POT1, will also be discussed. Genetics. We will describe these disorders from a genetic and clinical standpoint, focusing on the difference in clinical symptoms depending on the underlying gene or germline mutation. Central nervous system (CNS) tumors. Most of these disorders predispose the carriers to a wide range of symptoms. Herein, we will focus particularly on tumors affecting the CNS and discuss improvements of targeted therapy for the particular disorders. PMID:26634384

  17. Imaging of non tumorous and tumorous human brain tissue with full-field optical coherence tomography

    CERN Document Server

    Assayag, Osnath; Devaux, Bertrand; Harms, Fabrice; Pallud, Johan; Chretien, Fabrice; Boccara, Claude; Varlet, Pascale

    2013-01-01

    A prospective study was performed on neurosurgical samples from 18 patients to evaluate the use of Full-Field Optical Coherence Tomography (FF-OCT) in brain tumor diagnosis. FF-OCT captures en face slices of tissue samples at 1\\mum resolution in 3D with a typical 200\\mum imaging depth. A 1cm2 specimen is scanned at a single depth and processed in about 5 minutes. This rapid imaging process is non-invasive and 30 requires neither contrast agent injection nor tissue preparation, which makes it particularly well suited to medical imaging applications. Temporal chronic epileptic parenchyma and brain tumors such as meningiomas, low- grade and high-grade gliomas, and choroid plexus papilloma were imaged. A subpopulation of neurons, myelin fibers and CNS vasculature were clearly identified. Cortex could be discriminated from white matter, but individual glial cells as astrocytes (normal or reactive) or oligodendrocytes were not observable. This study reports for the first time on the feasibility of using FF-OCT in a...

  18. Silver nanoparticles induce tight junction disruption and astrocyte neurotoxicity in a rat blood–brain barrier primary triple coculture model

    Directory of Open Access Journals (Sweden)

    Xu L

    2015-09-01

    Full Text Available Liming Xu,1,2,* Mo Dan,1,* Anliang Shao,1 Xiang Cheng,1,3 Cuiping Zhang,4 Robert A Yokel,5 Taro Takemura,6 Nobutaka Hanagata,6 Masami Niwa,7,8 Daisuke Watanabe7,81National Institutes for Food and Drug Control, No 2, Temple of Heaven, Beijing, 2School of Information and Engineering, Wenzhou Medical University, Wenzhou, 3School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 4Beijing Neurosurgical Institute, Capital Medical University, Beijing, People’s Republic of China; 5College of Pharmacy, University of Kentucky, Lexington, KY, USA; 6Nanotechnology Innovation Station for Nanoscale Science and Technology, National Institute for Materials Science, Tsukuba, Ibaraki, 7Department of Pharmacology, Nagasaki University, 8BBB Laboratory, PharmaCo-Cell Company, Ltd., Nagasaki, Japan*These authors contributed equally to this workBackground: Silver nanoparticles (Ag-NPs can enter the brain and induce neurotoxicity. However, the toxicity of Ag-NPs on the blood–brain barrier (BBB and the underlying mechanism(s of action on the BBB and the brain are not well understood.Method: To investigate Ag-NP suspension (Ag-NPS-induced toxicity, a triple coculture BBB model of rat brain microvascular endothelial cells, pericytes, and astrocytes was established. The BBB permeability and tight junction protein expression in response to Ag-NPS, NP-released Ag ions, and polystyrene-NP exposure were investigated. Ultrastructural changes of the microvascular endothelial cells, pericytes, and astrocytes were observed using transmission electron microscopy (TEM. Global gene expression of astrocytes was measured using a DNA microarray.Results: A triple coculture BBB model of primary rat brain microvascular endothelial cells, pericytes, and astrocytes was established, with the transendothelial electrical resistance values >200 Ω·cm2. After Ag-NPS exposure for 24 hours, the BBB permeability was significantly increased and expression of the

  19. Endotoxemia-induced cytokine-mediated responses of hippocampal astrocytes transmitted by cells of the brain-immune interface.

    Science.gov (United States)

    Hasegawa-Ishii, Sanae; Inaba, Muneo; Umegaki, Hiroyuki; Unno, Keiko; Wakabayashi, Keiji; Shimada, Atsuyoshi

    2016-01-01

    Systemic inflammation shifts the brain microenvironment towards a proinflammatory state. However, how peripheral inflammation mediates changes in the brain remains to be clarified. We aimed to identify hippocampal cells and cytokines that respond to endotoxemia. Mice were intraperitoneally injected with lipopolysaccharide (LPS) or saline, and examined 1, 4, and 24 h after injection. Tissue cytokine concentrations in the spleens and hippocampi were determined by multiplex assays. Another group of mice were studied immunohistologically. Fourteen cytokines showed an increased concentration in the spleen, and 10 showed an increase in the hippocampus after LPS injection. Cytokines increased at 4 h (CCL2, CXCL1, CXCL2, and interleukin-6) were expressed by leptomeningeal stromal cells, choroid plexus stromal cells, choroid plexus epithelial cells, and hippocampal vascular endothelial cells, all of which were located at the brain-immune interface. Receptors for these cytokines were expressed by astrocytic endfeet. Cytokines increased at 24 h (CCL11, CXCL10, and granulocyte-colony stimulating factor) were expressed by astrocytes. Cells of the brain-immune interface therefore respond to endotoxemia with cytokine signals earlier than hippocampal parenchymal cells. In the parenchyma, astrocytes play a key role in responding to signals by using endfeet located in close apposition to the interface cells via cytokine receptors. PMID:27149601

  20. Astrocyte elevated gene-1 regulates astrocyte responses to neural injury: implications for reactive astrogliosis and neurodegeneration

    Directory of Open Access Journals (Sweden)

    Vartak-Sharma Neha

    2012-08-01

    Full Text Available Abstract Background Reactive astrogliosis is a ubiquitous but poorly understood hallmark of central nervous system pathologies such as trauma and neurodegenerative diseases. In vitro and in vivo studies have identified proinflammatory cytokines and chemokines as mediators of astrogliosis during injury and disease; however, the molecular mechanism remains unclear. In this study, we identify astrocyte elevated gene-1 (AEG-1, a human immunodeficiency virus 1 or tumor necrosis factor α-inducible oncogene, as a novel modulator of reactive astrogliosis. AEG-1 has engendered tremendous interest in the field of cancer research as a therapeutic target for aggressive tumors. However, little is known of its role in astrocytes and astrocyte-mediated diseases. Based on its oncogenic role in several cancers, here we investigate the AEG-1-mediated regulation of astrocyte migration and proliferation during reactive astrogliosis. Methods An in vivo brain injury mouse model was utilized to show AEG-1 induction following reactive astrogliosis. In vitro wound healing and cell migration assays following AEG-1 knockdown were performed to analyze the role of AEG-1 in astrocyte migration. AEG-1-mediated regulation of astrocyte proliferation was assayed by quantifying the levels of cell proliferation markers, Ki67 and proliferation cell nuclear antigen, using immunocytochemistry. Confocal microscopy was used to evaluate nucleolar localization of AEG-1 in cultured astrocytes following injury. Results The in vivo mouse model for brain injury showed reactive astrocytes with increased glial fibrillary acidic protein and AEG-1 colocalization at the wound site. AEG-1 knockdown in cultured human astrocytes significantly reduced astrocyte migration into the wound site and cell proliferation. Confocal analysis showed colocalization of AEG-1 to the nucleolus of injured cultured human astrocytes. Conclusions The present findings report for the first time the novel role of AEG-1

  1. Brain tumor and Gliadel wafer treatment

    Directory of Open Access Journals (Sweden)

    M Panigrahi

    2011-01-01

    Full Text Available Glioblastoma is a rapidly progressive and extremely fatal form of brain tumor with poor prognosis. It is the most common type of primary brain tumor. Even with the most aggressive conventional treatment that comprises surgery followed by radiotherapy and chemotherapy, most patients die within a year of diagnosis. Developments in molecular and cell biology have led to better understanding of tumor development, leading to novel treatment strategies including biological therapy and immunotherapy to combat the deadly disease. Targeted drug delivery strategies to circumvent the blood-brain barrier have shown efficiency in clinical trials. Gliadel wafer is a new approach to the treatment of glioblastoma, which involves controlled release delivery of carmustine from biodegradable polymer wafers. It has shown promising results and provides a silver lining for glioblastoma patients.

  2. Modulation of. beta. -adrenergic response in rat brain astrocytes by serum and hormones

    Energy Technology Data Exchange (ETDEWEB)

    Wu, D.K.; Morrison, R.S.; de Vellis, J.

    1985-01-01

    Purified astrocyte cultures from neonatal rat cerebrum respond to isoproterenol, a ..beta..-adrenergic agonist, with a transient rise in cAMP production. This astroglial property was regulated by serum, a chemically defined medium (serum-free medium plus hydrocortisone, putrescine, prostaglandin F/sub 2/, insulin, and fibroblast growth factor) and epidermal growth factor. Compared to astrocytes grown in serum-supplemented medium, astrocytes grown in the chemically defined medium were nonresponsive to isoproterenol stimulation, and this difference did not appear to be due to selection of a subpopulation of cells by either medium. The data suggest that a decreased ..beta..-adrenergic receptor number and an increased degradation of cAMP may account for the reduced response to ..beta..-adrenergic stimulation. The nonresponsive state of astrocytes in the defined medium was reversible when the medium was replaced with serum-supplemented medium. An active substance(s) in serum was responsible for restoring the responsiveness of astrocytes. Each of the five components of the defined medium had little effect by itself; however, together they acted synergistically to desensitize astrocytes to ..beta..-adrenergic stimulation. On the other hand, epidermal growth factor, a potent mitogen for astrocytes, was very competent by itself in reducing the cAMP response of astrocytes to ..beta..-adrenergic stimulation. Thus purified astrocytes grown in the chemically defined medium appear to be a good model for the study of hormonal interactions and of serum factors which may modulate the ..beta..-adrenergic response.

  3. Linac radiosurgery for metastatic brain tumor

    International Nuclear Information System (INIS)

    Metastatic brain tumors are usually the final stage in cancer progression. The aim of this study was to retrospectively determine optimal treatment strategies for linear accelerator stereotactic radiosurgery (SRS) and to investigate possible prognostic factors. Of 156 patients treated from 1990 to 2001, 124 patients with 312 lesions were treated with SRS alone, and followed-up for periods ranging from 15 days to 24 months (median 8.2 months). There were 86 males and 38 females, with a median age of 62.8 years. Tumor volume ranged from 0.04 to 50.5 ccm (median 7.9 ccm), and radiation doses ranged from 18 to 50 Gy (median 26.6 Gy in one fraction). Univariate and multivariate analyses of survival and tumor volume reduction rate were performed using Kaplan-Meier Curves, analysis of variance and log-rank test techniques. Median survival time was 8.2 months after SRS. The overall tumor control rate was 97.2%, with a complete or partial remission rate of 84.4%. The median follow-up time was 8.2 months following SRS. During follow-up, there was one case of fetal intracerebral hemorrhage (1.0%) and 6 cases of cerebral herniation (6.3%). Tumor reduction rate was related to tumor histology (p<0.01). Survival rate correlated with pre-SRS Karnofsky Performance Score (KPS) (p<0.01), a number of brain lesions (p=0.0075) and primary disease status (p<0.05), but was not related to progression of extracranial disease, age, lesion volume or lesion site. SRS is indicated for brain metastases under the following circumstances: lesions ≤40 mm in diameter, irradiation after reduction of tumor by paracentesis and suction of cystic lesion, a maximum of three tumors irradiated in one SRS, no concomitant whole brain irradiation, in general. (author)

  4. [Chemotherapy for brain tumors in adult patients].

    Science.gov (United States)

    Weller, M

    2008-02-01

    Chemotherapy has become a third major treatment option for patients with brain tumors, in addition to surgery and radiotherapy. The role of chemotherapy in the treatment of gliomas is no longer limited to recurrent disease. Temozolomide has become the standard of care in newly diagnosed glioblastoma. Several ongoing trials seek to define the role of chemotherapy in the primary care of other gliomas. Some of these studies are no longer only based on histological diagnoses, but take into consideration molecular markers such as MGMT promoter methylation and loss of genetic material on chromosomal arms 1p and 19q. Outside such clinical trials chemotherapy is used in addition to radiotherapy, e.g., in anaplastic astrocytoma, medulloblastoma or germ cell tumors, or as an alternative to radiotherapy, e.g., in anaplastic oligodendroglial tumors or low-grade gliomas. In contrast, there is no established role for chemotherapy in other tumors such as ependymomas, meningiomas or neurinomas. Primary cerebral lymphomas are probably the only brain tumors which can be cured by chemotherapy alone and only by chemotherapy. The chemotherapy of brain metastases follows the recommendations for the respective primary tumors. Further, strategies of combined radiochemotherapy using mainly temozolomide or topotecan are currently explored. Leptomeningeal metastases are treated by radiotherapy or systemic or intrathecal chemotherapy depending on their pattern of growth. PMID:18253773

  5. Galunisertib inhibits glioma vasculogenic mimicry formation induced by astrocytes

    OpenAIRE

    Chao Zhang; Wenliang Chen; Xin Zhang; Bin Huang; Aanjing Chen; Ying He; Jian Wang; Xingang Li

    2016-01-01

    Gliomas are among the most lethal primary brain tumors found in humans. In high-grade gliomas, vasculogenic mimicry is often detected and has been correlated with prognosis, thus suggesting its potential as a therapeutic target. Vasculogenic mimicry mainly forms vascular-like channels independent of endothelial cells; however, little is known about the relationship between astrocytes and vasculogenic mimicry. In our study, we demonstrated that the presence of astrocytes promoted vasculogenic ...

  6. Pediatric brain tumors of neuroepithelial tissue; Hirntumoren des neuroepithelialen Gewebes im Kindesalter

    Energy Technology Data Exchange (ETDEWEB)

    Papanagiotou, P.; Politi, M. [Klinikum Bremen-Mitte/Bremen-Ost, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Bremen (Germany); Bergmann, M. [Klinikum Bremen-Mitte, Institut fuer Klinische Neuropathologie, Bremen (Germany); Pekrun, A. [Klinikum Bremen-Mitte, Klinik fuer Kinder- und Jugendmedizin, paed. Haematologie/Onkologie, Neonatologie, Bremen (Germany); Juergens, K.U. [Klinikum Bremen-Mitte, ZEMODI-Zentrum fuer moderne Diagnostik, MRT, Nuklearmedizin und PET-CT, Bremen (Germany)

    2014-08-15

    Tumors of neuroepithelial tissue represent the largest group of pediatric brain tumors by far and has therefore been divided into several discrete tumor subtypes each corresponding to a specific component of the neuropil. The neuropil contains several subtypes of glial cells, including astrocytes, oligodendrocytes, ependymal cells and modified ependymal cells that form the choroid plexus. This review discusses the imaging aspects of the most common pediatric tumors of neuroepithelial tissue. (orig.) [German] Tumoren des neuroepithelialen Gewebes stellen die mit Abstand groesste Gruppe der paediatrischen Hirntumoren dar und werden je nach deren Ursprung in diversen Subtypen unterteilt. Das Neuropil beinhaltet diverse Subtypen von Gliazellen: Astrozyten, Oligodendrozyten, ependymale Zellen und modifizierte ependymale Zellen, die den Plexus choroideus formen. In diesem Review werden die bildgebenden Aspekte mittels CT und MRT der haeufigsten Tumoren des neuroepithelialen Gewebes diskutiert. (orig.)

  7. Calcium-activated potassium channels mediated blood-brain tumor barrier opening in a rat metastatic brain tumor model

    OpenAIRE

    2007-01-01

    Background The blood-brain tumor barrier (BTB) impedes the delivery of therapeutic agents to brain tumors. While adequate delivery of drugs occurs in systemic tumors, the BTB limits delivery of anti-tumor agents into brain metastases. Results In this study, we examined the function and regulation of calcium-activated potassium (KCa) channels in a rat metastatic brain tumor model. We showed that intravenous infusion of NS1619, a KCa channel agonist, and bradykinin selectively enhanced BTB perm...

  8. A subconvulsive dose of kainate selectively compromises astrocytic metabolism in the mouse brain in vivo

    DEFF Research Database (Denmark)

    Walls, Anne B; Eyjolfsson, Elvar M; Schousboe, Arne;

    2014-01-01

    cerebral metabolism and particularly that associated with astrocytes. We investigated astrocytic and neuronal metabolism in the cerebral cortex of adult mice after treatment with saline (controls), a subconvulsive or a mildly convulsive dose of kainate. A combination of [1,2-(13)C]acetate and [1-(13)C......]glucose was injected and subsequent nuclear magnetic resonance spectroscopy of cortical extracts was employed to distinctively map astrocytic and neuronal metabolism. The subconvulsive dose of kainate led to an instantaneous increase in the cortical lactate content, a subsequent reduction in the amount of [4......,5-(13)C]glutamine and an increase in the calculated astrocytic TCA cycle activity. In contrast, the convulsive dose led to decrements in the cortical content and (13)C labeling of glutamate, glutamine, GABA, and aspartate. Evidence is provided that astrocytic metabolism is affected by a subconvulsive dose...

  9. Recent advances in imaging of brain tumors

    Directory of Open Access Journals (Sweden)

    D A Sanghvi

    2009-01-01

    The next decade will witness further sophistication of these techniques, with data available from larger studies. It is expected that imaging will continue to provide new and unique insights in neuro-oncology, which should hopefully contribute to the better management of patients with brain tumors.

  10. MicroRNA and Brain Tumors

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    MicroRNAs (miRNAs) were first described in 1993 by Lee and colleagues, and the term microRNA was only introduced in 2001 in a set of three articles in Science[1]. One of the biggest surprises in the past few years has been the emergence of miRNAs as a major new class of gene expression regulators. Recent studies suggest that miRNA alterations are involved in the initiation and progression of human cancer. The brain tumor,glioblastoma multiforme, is the most malignant and deadly form of gliomas.The prognosis is poor and the median survival with combined radiotherapy and chemotherapy is only 14.6 months. With the discovery of miRNA, the miRNA profiles may become useful biomarkers for brain tumor diagnostics,and miRNA therapy could be a powerful tool for brain tumor prevention and therapeutics. This review outlines the background of miRNA and its expression and therapeutic potential for brain tumors.

  11. In vitro model of the blood-brain barrier established by co-culture of primary cerebral microvascular endothelial and astrocyte cells

    OpenAIRE

    Yan Wang; Ning Wang; Biao Cai; Guang-yun Wang; Jing Li; Xing-xing Piao

    2015-01-01

    Drugs for the treatment and prevention of nervous system diseases must permeate the blood-brain barrier to take effect. In vitro models of the blood-brain barrier are therefore important in the investigation of drug permeation mechanisms. However, to date, no unified method has been described for establishing a blood-brain barrier model. Here, we modified an in vitro model of the blood-brain barrier by seeding brain microvascular endothelial cells and astrocytes from newborn rats on a polyest...

  12. The electroencephalogram in metastatic brain tumors

    Directory of Open Access Journals (Sweden)

    P. Pinto Pupo

    1967-12-01

    Full Text Available Sixty cases of intracranial metastatic tumors diagnosed either clinically or by neurosurgery (28 operative cases, 26 with radiological contrast examinations and 6 with clinical diagnosis only are reported. The EEG tests had been made previously to the diagnosis of metastasis. The EEG results are analysed according to the previous impression gained from this test and are presented in 5 tables, on which the cases are divided as per the brain topography of the metastasis. The positive EEG data are analysed and the possibility of topographic diagnosis discussed. The results agree with those presented in the literature. The AA. reach the following conclusions: 1 in patients with suspect brain metastasis the normal EEG allows with great probability to exclude the possibility; 2 in patients with malignant tumor the EEG signs of involvement of the nervous parenchyma are the most important elements for positive diagnosis of brain metastasis; 3 in the cases of metastasis developing at the posterior fossa, either there were indicative signs of the process at that level or the EEG was normal; 4 the EEG signs of an irritant process at the brain cortex were less frequent and, in the majority of cases, appeared in the temporal and parietal areas; 5 the signs of involvement of the mesodiencephalic structures in tumors of the brain hemispheres appeared only when the tumor was located in the median part of the hemisphere (temporal or parietal lobes; 6 signs of depression of the basal electric brain activity in the affected areas appeared rarely and in cases of parietal or occipital tumors; 7 the electric brain activity of other areas of the involved hemisphere or in the opposite hemisphere was normal in the majority of the cases observed. Considering the results of the literature and their own the AA. believe that the EEG could be a semiological method to be used at the preoperative examinations of patients with malignant tumors, with a view at establishing the

  13. Malignant brain tumor treatments and hyperbaric oxygenation

    Energy Technology Data Exchange (ETDEWEB)

    Kohshi, Kiyotaka [Univ. of Occupational and Environmental Health, Kitakyushu, Fukuoka (Japan)

    2000-09-01

    Malignant brain tumor treatment and hyperbaric oxygenation: Combined hyperbaric oxygenation (HBO) therapy and radiation therapy of malignant gliomas is reviewed. Malignant glioma tissue is hypoxic, and the efficacy of radiation therapy is increased by raising the oxygen density in glioma tissue. Residual tumor was reduced by a radiation dose of approximately 40 Gy in many cases when radiation therapy was begun within 15 minutes after HBO. In the experiment in animal models with different hypoxic fractions (HFs) of cells (SCCVII and 9L gliosarcoma), the tumor reduction effect was more significant in the SCCVII model, which has a higher HF. When the SCCVII model was irradiated within 30 minutes after HBO, the improvement effect was more significant (1.60-1.78 times) than by irradiation alone. HBO was effective in the treatment of radionecrosis of the brain. However, there were some cases in which radionecrosis progressed when the HBO treatments were discontinued, and the optimal duration of HBO treatment should be determined. It is difficult to differentiate between radionecrosis and tumor recurrence after radiosurgery of a malignant intracranial tumor. When no lesion reduction is observed in response to HBO treatment and steroid administration for about one month, the lesion is concluded to be a recurrence of the tumor, and additional irradiation should be performed. HBO treatment in combination with chemotherapy is also discussed. (K.H.)

  14. Malignant brain tumor treatments and hyperbaric oxygenation

    International Nuclear Information System (INIS)

    Malignant brain tumor treatment and hyperbaric oxygenation: Combined hyperbaric oxygenation (HBO) therapy and radiation therapy of malignant gliomas is reviewed. Malignant glioma tissue is hypoxic, and the efficacy of radiation therapy is increased by raising the oxygen density in glioma tissue. Residual tumor was reduced by a radiation dose of approximately 40 Gy in many cases when radiation therapy was begun within 15 minutes after HBO. In the experiment in animal models with different hypoxic fractions (HFs) of cells (SCCVII and 9L gliosarcoma), the tumor reduction effect was more significant in the SCCVII model, which has a higher HF. When the SCCVII model was irradiated within 30 minutes after HBO, the improvement effect was more significant (1.60-1.78 times) than by irradiation alone. HBO was effective in the treatment of radionecrosis of the brain. However, there were some cases in which radionecrosis progressed when the HBO treatments were discontinued, and the optimal duration of HBO treatment should be determined. It is difficult to differentiate between radionecrosis and tumor recurrence after radiosurgery of a malignant intracranial tumor. When no lesion reduction is observed in response to HBO treatment and steroid administration for about one month, the lesion is concluded to be a recurrence of the tumor, and additional irradiation should be performed. HBO treatment in combination with chemotherapy is also discussed. (K.H.)

  15. Brain tumors in childhood; Hirntumoren im Kindesalter

    Energy Technology Data Exchange (ETDEWEB)

    Sinzig, M.; Gasser, J.; Hausegger, K.A. [Landeskrankenhaus Klagenfurt, Kinderradiologie RZI, Klagenfurt (Austria); Jauk, B. [Landeskrankenhaus Klagenfurt, Abt. fuer Kinder- und Jugendheilkunde, Klagenfurt (Austria)

    2008-10-15

    Central nervous system (CNS) tumors are the most common solid neoplasms in childhood and the second most common malignancies after leukemia in the pediatric age group. Supratentorial tumors are more common in children younger than 2 years old and in adolescents, whereas in patients between 2 and 12 years of age brain tumors originating in the posterior fossa dominate. This implies a relationship between the type of tumor, its location and the age of the patient, which has to be considered in differential diagnoses. Medulloblastoma represents the most common malignant brain tumor in childhood. In the posterior fossa medulloblastomas are approximately as frequent as astrocytomas. Supratentorial astrocytomas are by far the main tumor type. In this report some typical CNS neoplasms in children are discussed and their neuroradiological features are demonstrated. (orig.) [German] Hirntumoren sind die haeufigsten soliden Tumoren des Kindesalters und repraesentieren nach den Leukaemien die zweithaeufigsten malignen Erkrankungen bei Kindern. Waehrend bei Kleinkindern und Adoleszenten supratentorielle Hirntumoren ueberwiegen, ist bei Patienten zwischen 2 und 12 Jahren haeufiger die hintere Schaedelgrube Ursprungsort dieser Malignome. Daraus geht hervor, dass gewisse Tumortypen eine gewisse Alterspraedilektion aufweisen, was neben der radiologischen Morphologie der Raumforderung fuer differenzialdiagnostische Ueberlegungen ueberaus hilfreich sein kann. Das Medulloblastom ist das haeufigste ZNS-Malignom des Kindesalters und repraesentiert zusammen mit zerebellaeren Astrozytomen auch den haeufigsten Tumortyp der hinteren Schaedelgrube. Supratentoriell stehen die Astrozytome ganz im Vordergrund. In dieser Arbeit werden einige typische kindliche infra- und supratentorielle Hirntumoren diskutiert und ihre neuroradiologischen Merkmale dargestellt. (orig.)

  16. Role of astrocytic leptin receptor subtypes on leptin permeation across hCMEC/D3 human brain endothelial cells.

    Science.gov (United States)

    Hsuchou, Hung; Kastin, Abba J; Tu, Hong; Joan Abbott, N; Couraud, Pierre-Olivier; Pan, Weihong

    2010-12-01

    Astrocytic leptin receptors (ObR) can be up-regulated in conditions such as adult-onset obesity. To determine whether the levels and subtypes of astrocytic ObR modulate leptin transport, we co-cultured hCMEC/D3 human brain endothelial cells and C6 astrocytoma cells in the Transwell system, and tested leptin permeation from apical to basolateral chambers. In comparison with hCMEC alone, co-culture of C6 cells reduced the permeability of paracellular markers and leptin. Unexpectedly, ObRb over-expression in C6 cells increased leptin permeation whereas ObRa over-expression showed no effect when compared with the control group of pcDNA-transfected C6 cells. By contrast, the paracellular permeability to the sodium fluorescein control was unchanged by over-expression of ObR subtypes. Leptin remained intact after crossing the monolayer as shown by HPLC and acid precipitation, and this was not affected by C6 cell co-culture or the over-expression of different ObR subtypes. Thus, increased expression of ObRb (and to a lesser extent ObRe) in C6 cells specifically increased the permeation of leptin across the hCMEC monolayer. Consistent with the evidence that the most apparent regulatory changes of ObR during obesity and inflammation occur in astrocytes, the results indicate that astrocytes actively regulate leptin transport across the blood-brain barrier, a mechanism independent of reduction of paracellular permeability. PMID:20977476

  17. The Neurogenic Potential of Astrocytes Is Regulated by Inflammatory Signals.

    Science.gov (United States)

    Michelucci, Alessandro; Bithell, Angela; Burney, Matthew J; Johnston, Caroline E; Wong, Kee-Yew; Teng, Siaw-Wei; Desai, Jyaysi; Gumbleton, Nigel; Anderson, Gregory; Stanton, Lawrence W; Williams, Brenda P; Buckley, Noel J

    2016-08-01

    Although the adult brain contains neural stem cells (NSCs) that generate new neurons throughout life, these astrocyte-like populations are restricted to two discrete niches. Despite their terminally differentiated phenotype, adult parenchymal astrocytes can re-acquire NSC-like characteristics following injury, and as such, these 'reactive' astrocytes offer an alternative source of cells for central nervous system (CNS) repair following injury or disease. At present, the mechanisms that regulate the potential of different types of astrocytes are poorly understood. We used in vitro and ex vivo astrocytes to identify candidate pathways important for regulation of astrocyte potential. Using in vitro neural progenitor cell (NPC)-derived astrocytes, we found that exposure of more lineage-restricted astrocytes to either tumor necrosis factor alpha (TNF-α) (via nuclear factor-κB (NFκB)) or the bone morphogenetic protein (BMP) inhibitor, noggin, led to re-acquisition of NPC properties accompanied by transcriptomic and epigenetic changes consistent with a more neurogenic, NPC-like state. Comparative analyses of microarray data from in vitro-derived and ex vivo postnatal parenchymal astrocytes identified several common pathways and upstream regulators associated with inflammation (including transforming growth factor (TGF)-β1 and peroxisome proliferator-activated receptor gamma (PPARγ)) and cell cycle control (including TP53) as candidate regulators of astrocyte phenotype and potential. We propose that inflammatory signalling may control the normal, progressive restriction in potential of differentiating astrocytes as well as under reactive conditions and represent future targets for therapies to harness the latent neurogenic capacity of parenchymal astrocytes. PMID:26138449

  18. Targeted Toxins in Brain Tumor Therapy

    Directory of Open Access Journals (Sweden)

    Walter A. Hall

    2010-11-01

    Full Text Available Targeted toxins, also known as immunotoxins or cytotoxins, are recombinant molecules that specifically bind to cell surface receptors that are overexpressed in cancer and the toxin component kills the cell. These recombinant proteins consist of a specific antibody or ligand coupled to a protein toxin. The targeted toxins bind to a surface antigen or receptor overexpressed in tumors, such as the epidermal growth factor receptor or interleukin-13 receptor. The toxin part of the molecule in all clinically used toxins is modified from bacterial or plant toxins, fused to an antibody or carrier ligand. Targeted toxins are very effective against cancer cells resistant to radiation and chemotherapy. They are far more potent than any known chemotherapy drug. Targeted toxins have shown an acceptable profile of toxicity and safety in early clinical studies and have demonstrated evidence of a tumor response. Currently, clinical trials with some targeted toxins are complete and the final results are pending. This review summarizes the characteristics of targeted toxins and the key findings of the important clinical studies with targeted toxins in malignant brain tumor patients. Obstacles to successful treatment of malignant brain tumors include poor penetration into tumor masses, the immune response to the toxin component and cancer heterogeneity. Strategies to overcome these limitations are being pursued in the current generation of targeted toxins.

  19. Gene Expression Analysis of Neurons and Astrocytes Isolated by Laser Capture Microdissection from Frozen Human Brain Tissues.

    Science.gov (United States)

    Tagliafierro, Lidia; Bonawitz, Kirsten; Glenn, Omolara C; Chiba-Falek, Ornit

    2016-01-01

    Different cell types and multiple cellular connections characterize the human brain. Gene expression analysis using a specific population of cells is more accurate than conducting analysis of the whole tissue homogenate, particularly in the context of neurodegenerative diseases, where a specific subset of cells is affected by the different pathology. Due to the difficulty of obtaining homogenous cell populations, gene expression in specific cell-types (neurons, astrocytes, etc.) has been understudied. To leverage the use of archive resources of frozen human brains in studies of neurodegenerative diseases, we developed and calibrated a method to quantify cell-type specific-neuronal, astrocytes-expression profiles of genes implicated in neurodegenerative diseases, including Parkinson's and Alzheimer's diseases. Archive human frozen brain tissues were used to prepare slides for rapid immunostaining using cell-specific antibodies. The immunoreactive-cells were isolated by Laser Capture Microdissection (LCM). The enrichment for a particular cell-type of interest was validated in post-analysis stage by the expression of cell-specific markers. We optimized the technique to preserve the RNA integrity, so that the RNA was suitable for downstream expression analyses. Following RNA extraction, the expression levels were determined digitally using nCounter Single Cell Gene Expression assay (NanoString Technologies®). The results demonstrated that using our optimized technique we successfully isolated single neurons and astrocytes from human frozen brain tissues and obtained RNA of a good quality that was suitable for mRNA expression analysis. We present here new advancements compared to previous reported methods, which improve the method's feasibility and its applicability for a variety of downstream molecular analyses. Our new developed method can be implemented in genetic and functional genomic research of neurodegenerative diseases and has the potential to significantly

  20. Potential of Neural Stem Cells for the Treatment of Brain Tumors

    Directory of Open Access Journals (Sweden)

    P. Taupin

    2008-01-01

    Full Text Available Neural stem cells (NSCs are self-renewing multipotent cells that generate the main phenotypes of the nervous system, neurons, astrocytes and oligodendrocytes. As such they hold the promise to treat a broad range of neurological diseases and injuries. Neural progenitor and stem cells have been isolated and characterized in vitro, from adult, fetal and post-mortem tissues, providing sources of material for cellular therapy. However, NSCs are still elusive cells and remain to be unequivocally identified and characterized, limiting their potential use for therapy. Neural progenitor and stem cells, isolated and cultured in vitro, can be genetically modified and when transplanted migrate to tumor sites in the brain. These intrinsic properties of neural progenitor and stem cells provide tremendous potential to bolster the translation of NSC research to therapy. It is proposed to combine gene therapy and cellular therapy to treat brain cancers. Hence, neural progenitor and stem cells provide new opportunities for the treatment of brain cancers.

  1. Mapping of language brain areas in patients with brain tumors.

    Science.gov (United States)

    Hyder, Rasha; Kamel, Nidal; Boon, Tang Tong; Reza, Faruque

    2015-08-01

    Language cortex in the human brain shows high variability among normal individuals and may exhibit a considerable shift from its original position due to tumor growth. Mapping the precise location of language areas is important before surgery to avoid postoperative language deficits. In this paper, the Magnetoencephalography (MEG) recording and the MRI scanning of six brain tumorous subjects are used to localize the language specific areas. MEG recordings were performed during two silent reading tasks; silent word reading and silent picture naming. MEG source imaging is performed using distributed source modeling technique called CLARA ("Classical LORETA Analysis Recursively Applied"). Estimated MEG sources are overlaid on individual MRI of each patient to improve interpretation of MEG source imaging results. The results show successful identification of the essential language areas and clear definition of the time course of neural activation connecting them. PMID:26736340

  2. Brain tumors in man and animals: report of a workshop.

    OpenAIRE

    1986-01-01

    This report summarizes the results of a workshop on brain tumors in man and animals. Animals, especially rodents are often used as surrogates for man to detect chemicals that have the potential to induce brain tumors in man. Therefore, the workshop was focused mainly on brain tumors in the F344 rat and B6C3F1 mouse because of the frequent use of these strains in long-term carcinogenesis studies. Over 100 brain tumors in F344 rats and more than 50 brain tumors in B6C3F1 mice were reviewed and ...

  3. Brain Tumor Detection Based On Symmetry Information

    OpenAIRE

    G., Narkhede Sachin; Khairnar, Vaishali

    2013-01-01

    Advances in computing technology have allowed researchers across many fields of endeavor to collect and maintain vast amounts of observational statistical data such as clinical data, biological patient data, data regarding access of web sites, financial data, and the like. This paper addresses some of the challenging issues on brain magnetic resonance (MR) image tumor segmentation caused by the weak correlation between magnetic resonance imaging (MRI) intensity and anatomical meaning. With th...

  4. Copper Metabolism of Astrocytes

    Directory of Open Access Journals (Sweden)

    Ralf eDringen

    2013-03-01

    Full Text Available This short review will summarize the current knowledge on the uptake, storage and export of copper ions by astrocytes and will address the potential roles of astrocytes in copper homeostasis in the normal and diseased brain. Astrocytes in culture efficiently accumulate copper by processes that include both the copper transporter Ctr1 and Ctr1-independent mechanisms. Exposure of astrocytes to copper induces an increase in cellular glutathione (GSH content as well as synthesis of metallothioneins, suggesting that excess of copper is stored as complex with GSH and in metallothioneins. Furthermore, exposure of astrocytes to copper accelerates the release of GSH and of glycolytically generated lactate. Astrocytes are able to export copper and express the Menkes protein ATP7A. This protein undergoes reversible, copper-dependent trafficking between the trans-Golgi network and vesicular structures. The ability of astrocytes to efficiently take up, store and export copper suggests that astrocytes play a key role in the supply of neurons with copper and that astrocytes should be considered as target for therapeutic inventions that aim to correct disturbances in brain copper homeostasis.

  5. Effects of atrial and brain natriuretic peptides upon cyclic GMP levels, potassium transport, and receptor binding in rat astrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Beaumont, K.; Tan, P.K. (Univ. of California, San Diego, La Jolla (USA))

    1990-02-01

    The ability of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) to alter cyclic GMP levels and NaKCl cotransport in rat neocortical astrocytes was determined. At concentrations of 10(-9)-10(-6) M, rat ANP99-126 (rANF), rat ANP102-126 (auriculin B), and rat ANP103-126 (atriopeptin III) stimulated 6- to 100-fold increases in cyclic GMP levels. Porcine BNP (pBNP) and rat BNP (rBNP) were 20%-90% as effective as rANF over most of this concentration range, although 10(-6) M pBNP produced a greater effect than rANF. NaKCl cotransport as measured by bumetanide-sensitive 86Rb+ influx was not altered by exposure of astrocytes to 10(-6)M rANF, pBNP, or rBNP. Both pBNP and rBNP, as well as rat ANP103-123 (atriopeptin I) and des(gl18, ser19, gly20, leu21, gly22) ANF4-23-NH2 (C-ANF4-23) strongly competed for specific 125I-rANF binding sites in astrocyte membranes with affinities ranging from 0.03 to 0.4 nM, suggesting that virtually all binding sites measured at subnanomolar concentrations of 125I-rANF were of the ANP-C (ANF-R2) receptor subtype. These receptors are thought to serve a clearance function and may be linked to a guanylate cyclase activity that is chemically and pharmacologically distinct from that coupled to ANP-A (ANF-R1) receptors. ANP receptors on astrocytes may function in limiting the access of ANP and BNP to neurons involved in body fluid and cardiovascular regulation.

  6. Astrocyte-derived proinflammatory cytokines induce hypomyelination in the periventricular white matter in the hypoxic neonatal brain.

    Directory of Open Access Journals (Sweden)

    Yiyu Deng

    Full Text Available Hypoxic exposure in the perinatal period causes periventricular white matter damage (PWMD, a condition associated with myelination abnormalities. Under hypoxic conditions, glial cells were activated and released a large number of inflammatory mediators in the PWM in neonatal brain, which may result in oligodendrocyte (OL loss and axonal injury. This study aims to determine if astrocytes are activated and generate proinflammatory cytokines that may be coupled with the oligodendroglial loss and hypomyelination observed in hypoxic PWMD. Twenty-four 1-day-old Wistar rats were exposed to hypoxia for 2 h. The rats were then allowed to recover under normoxic conditions for 7 or 28 days before being killed. Another group of 24 rats kept outside the chamber was used as age-matched controls. Upregulated expression of TNF-α and IL-1β was observed in astrocytes in the PWM of P7 hypoxic rats by double immunofluorescence, western blotting and real time RT-PCR. This was linked to apoptosis and enhanced expression of TNF-R1 and IL-1R1 in APC(+ OLs. PLP expression was decreased significantly in the PWM of P28d hypoxic rats. The proportion of myelinated axons was markedly reduced by electron microscopy (EM and the average g-ratios were higher in P28d hypoxic rats. Upregulated expression of TNF-α and IL-1β in primary cultured astrocytes as well as their corresponding receptors in primary culture APC(+ oligodendrocytes were detected under hypoxic conditions. Our results suggest that following a hypoxic insult, astrocytes in the PWM of neonatal rats produce inflammatory cytokines such as TNF-α and IL-1β, which induce apoptosis of OLs via their corresponding receptors associated with them. This results in hypomyelination in the PWM of hypoxic rats.

  7. Effects of atrial and brain natriuretic peptides upon cyclic GMP levels, potassium transport, and receptor binding in rat astrocytes

    International Nuclear Information System (INIS)

    The ability of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) to alter cyclic GMP levels and NaKCl cotransport in rat neocortical astrocytes was determined. At concentrations of 10(-9)-10(-6) M, rat ANP99-126 (rANF), rat ANP102-126 (auriculin B), and rat ANP103-126 (atriopeptin III) stimulated 6- to 100-fold increases in cyclic GMP levels. Porcine BNP (pBNP) and rat BNP (rBNP) were 20%-90% as effective as rANF over most of this concentration range, although 10(-6) M pBNP produced a greater effect than rANF. NaKCl cotransport as measured by bumetanide-sensitive 86Rb+ influx was not altered by exposure of astrocytes to 10(-6)M rANF, pBNP, or rBNP. Both pBNP and rBNP, as well as rat ANP103-123 (atriopeptin I) and des[gl18, ser19, gly20, leu21, gly22] ANF4-23-NH2 (C-ANF4-23) strongly competed for specific 125I-rANF binding sites in astrocyte membranes with affinities ranging from 0.03 to 0.4 nM, suggesting that virtually all binding sites measured at subnanomolar concentrations of 125I-rANF were of the ANP-C (ANF-R2) receptor subtype. These receptors are thought to serve a clearance function and may be linked to a guanylate cyclase activity that is chemically and pharmacologically distinct from that coupled to ANP-A (ANF-R1) receptors. ANP receptors on astrocytes may function in limiting the access of ANP and BNP to neurons involved in body fluid and cardiovascular regulation

  8. Cerebral radiofrequency exposures during adolescence: Impact on astrocytes and brain functions in healthy and pathologic rat models.

    Science.gov (United States)

    Petitdant, Nicolas; Lecomte, Anthony; Robidel, Franck; Gamez, Christelle; Blazy, Kelly; Villégier, Anne-Sophie

    2016-07-01

    The widespread use of mobile phones by adolescents raises concerns about possible health effects of radiofrequency electromagnetic fields (RF EMF 900 MHz) on the immature brain. Neuro-development is a period of particular sensitivity to repeated environmental challenges such as pro-inflammatory insults. Here, we used rats to assess whether astrocyte reactivity, perception, and emotionality were affected by RF EMF exposures during adolescence. We also investigated if adolescent brains were more sensitive to RF EMF exposures after neurodevelopmental inflammation. To do so, we either performed 80 μg/kg intra-peritoneal injections of lipopolysaccharides during gestation or 1.25 μg/h intra-cerebro-ventricular infusions during adolescence. From postnatal day (P)32 to 62, rats were subjected to 45 min RF EMF exposures to the brain (specific absorption rates: 0, 1.5, or 6 W/kg, 5 days/week). From P56, they were tested for perception of novelty, anxiety-like behaviors, and emotional memory. To assess astrocytic reactivity, Glial Fibrillary Acidic Protein was measured at P64. Our results did not show any neurobiological impairment in healthy and vulnerable RF EMF-exposed rats compared to their sham-exposed controls. These data did not support the hypothesis of a specific cerebral sensitivity to RF EMF of adolescents, even after a neurodevelopmental inflammation. Bioelectromagnetics. 37:338-350, 2016. © 2016 Wiley Periodicals, Inc. PMID:27272062

  9. Extracellular Vesicles in Brain Tumor Progression.

    Science.gov (United States)

    D'Asti, Esterina; Chennakrishnaiah, Shilpa; Lee, Tae Hoon; Rak, Janusz

    2016-04-01

    Brain tumors can be viewed as multicellular 'ecosystems' with increasingly recognized cellular complexity and systemic impact. While the emerging diversity of malignant disease entities affecting brain tissues is often described in reference to their signature alterations within the cellular genome and epigenome, arguably these cell-intrinsic changes can be regarded as hardwired adaptations to a variety of cell-extrinsic microenvironmental circumstances. Conversely, oncogenic events influence the microenvironment through their impact on the cellular secretome, including emission of membranous structures known as extracellular vesicles (EVs). EVs serve as unique carriers of bioactive lipids, secretable and non-secretable proteins, mRNA, non-coding RNA, and DNA and constitute pathway(s) of extracellular exit of molecules into the intercellular space, biofluids, and blood. EVs are also highly heterogeneous as reflected in their nomenclature (exosomes, microvesicles, microparticles) attempting to capture their diverse origin, as well as structural, molecular, and functional properties. While EVs may act as a mechanism of molecular expulsion, their non-random uptake by heterologous cellular recipients defines their unique roles in the intercellular communication, horizontal molecular transfer, and biological activity. In the central nervous system, EVs have been implicated as mediators of homeostasis and repair, while in cancer they may act as regulators of cell growth, clonogenicity, angiogenesis, thrombosis, and reciprocal tumor-stromal interactions. EVs produced by specific brain tumor cell types may contain the corresponding oncogenic drivers, such as epidermal growth factor receptor variant III (EGFRvIII) in glioblastoma (and hence are often referred to as 'oncosomes'). Through this mechanism, mutant oncoproteins and nucleic acids may be transferred horizontally between cellular populations altering their individual and collective phenotypes. Oncogenic pathways

  10. Angiotensin II induces secretion of plasminogen activator inhibitor 1 and a tissue metalloprotease inhibitor-related protein from rat brain astrocytes

    International Nuclear Information System (INIS)

    The present study investigates angiotensin (Ang) II effects on secretory protein synthesis in brain astrocytes cultured from neonatal and 21-day-old rats. Ang II-induced changes in the de novo synthesis of [35S]methionine-labeled secretory proteins were visualized using two-dimensional NaDodSO4/PAGE. Astrocytes from 21-day-old rat brain possess specific high-affinity receptors for Ang II. These cells express two Ang II-induced secretory proteins with Mr 55,000 (AISP-55K) and Mr 30,000 (AISP-30K), which were time- and dose-dependent (EC50, 1 nM). [Sar1, Ile8]Ang II (where Sar is sarcosine) inhibited Ang II-induced secretion of AISP-55K but not AISP-30K. N-terminal amino acid sequencing indicates that AISP-55K is identical to rat plasminogen activator inhibitor 1, whereas AISP-30K exhibits 72-81% identity to three closely related proteins: human tissue inhibitor of metalloproteases, a rat phorbol ester-induced protein, and the murine growth-responsive protein 16C8. Immunofluorescent staining with rat plasminogen activator inhibitor 1 antibody was induced in the majority of cells in culture after Ang II treatment of astrocytes from 21-day-old rat brains. Absence of this response to Ang II in astrocytes from neonatal rat brain provides evidence that this action of Ang II on astrocytes is developmentally regulated

  11. Gamma knife radiosurgery for metastatic brain tumors from lung cancer

    International Nuclear Information System (INIS)

    The purpose of this retrospective study is to evaluate the effectiveness of gamma knife radiosurgery (GKS) alone for metastatic brain tumors from lung cancer. Two hundred thirty-one consecutive patients with metastatic brain tumors from lung cancer filling the following 4 criteria were analyzed for this study; no prior brain tumor treatment, 25 or fewer lesions, a maximum 5 tumors with diameter of 2 cm or more, no surgically inaccessible tumor 3 cm or greater in diameter. According to the same treatment protocol, large tumors (≥ 3 cm) were surgically removed and all the other small lesions (10 brain lesions. This study suggests the results of GKS for metastatic brain tumors from lung cancer are quite satisfactory considering prevention of neurological death and maintenance of QOL. But cases with carcinomatous meningitis and/or >10 brain lesions are not good candidates for GKS alone. (author)

  12. Non-FDG PET imaging of brain tumors

    Institute of Scientific and Technical Information of China (English)

    HUANG Zemin; GUAN Yihui; ZUO Chuantao; ZHANG Zhengwei; XUE Fangping; LIN Xiangtong

    2007-01-01

    Due to relatively high uptake of glucose in the brain cortex, the use of FDG PET imaging is greatly limited in brain tumor imaging, especially for low-grade gliomas and some metastatic tumours. More and more tracers with higher specificity were developed lately for brain tumor imaging. There are 3 main types of non-FDG PET tracers:amino acid tracers, choline tracers and nucleic acid tracers. These tracers are now widely applied in many aspects of brain tumor imaging. This article summarized the general use of non-FDG PET in different aspects of brain tumor imaging.

  13. P2Y2 receptor up-regulation induced by guanosine or UTP in rat brain cultured astrocytes.

    Science.gov (United States)

    Ballerini, P; Di Iorio, P; Caciagli, F; Rathbone, M P; Jiang, S; Nargi, E; Buccella, S; Giuliani, P; D'Alimonte, I; Fischione, G; Masciulli, A; Romano, S; Ciccarelli, R

    2006-01-01

    Among P2 metabotropic ATP receptors, P2Y2 subtype seems to be peculiar as its upregulation triggers important biological events in different cells types. In non-stimulated cells including astrocytes, P2Y2 receptors are usually expressed at levels lower than P2Y1 sites, however the promoter region of the P2Y2 receptors has not yet been studied and little is known about the mechanisms underlying the regulation of the expression of this ATP receptor. We showed that not only UTP and ATP are the most potent and naturally occurring agonist for P2Y2 sites, but also guanosine induced an up-regulation of astrocyte P2Y2 receptor mRNA evaluated by Northern blot analysis. We also focused our attention on this nucleoside since in our previous studies it was reported to be released by cultured astrocytes and to exert different neuroprotective effects. UTP and guanosine-evoked P2Y2 receptor up-regulation in rat brain cultured astrocytes was linked to an increased P2Y2-mediated intracellular calcium response, thus suggesting an increased P2Y2 activity. Actinomycin D, a RNA polymerase inhibitor, abrogated both UTP and guanosine-mediated P2Y2 up-regulation, thus indicating that de novo transcription was required. The effect of UTP and guanosine was also evaluated in astrocytes pretreated with different inhibitors of signal transduction pathways including ERK, PKC and PKA reported to be involved in the regulation of other cell surface receptor mRNAs. The results show that ERK1-2/MAPK pathway play a key role in the P2Y2 receptor up-regulation mediated by either UTP or guanosine. Moreover, our data suggest that PKA is also involved in guanosine-induced transcriptional activation of P2Y2 mRNA and that increased intracellular calcium levels and PKC activation may also mediate P2Y2 receptor up-regulation triggered by UTP. The extracellular release of ATP under physiological and pathological conditions has been widely studied. On the contrary, little is known about the release of

  14. Redefining the role of metallothionein within the injured brain: extracellular metallothioneins play an important role in the astrocyte-neuron response to injury

    DEFF Research Database (Denmark)

    Chung, Roger S; Penkowa, Milena; Dittmann, Justin;

    2008-01-01

    A number of intracellular proteins that are protective after brain injury are classically thought to exert their effect within the expressing cell. The astrocytic metallothioneins (MT) are one example and are thought to act via intracellular free radical scavenging and heavy metal regulation, and......-dependent axonal regeneration. First, we show that MT can be detected within the extracellular fluid of the injured brain, and that cultured astrocytes are capable of actively secreting MT in a regulatable manner. Second, we identify a receptor, megalin, that mediates MT transport into neurons. Third, we directly...

  15. Nuclear magnetic resonance imaging in brain tumors

    International Nuclear Information System (INIS)

    Full text: Magnetic resonance imaging (MRI) is a non-invasive imaging method based on the detecting signal from hydrogen nuclei of water molecules and fat. Performances of MRI are continuously increasing, and its domains of investigation of the human body are growing in both morphological and functional study. MRI also allows It also performing advanced management of tumours especially in the brain, by combining anatomical information (morphological MRI), functional (diffusion, perfusion and BOLD contrast) and metabolic (tissue composition in magnetic resonance spectroscopy (MRS)). The MRI techniques have an important role in cancerology. These techniques allow essential information for the diagnosis and answering therapist's questions before, during or after the treatment. The MR allows clarifying the localization of expanding processes, the differential diagnosis between brain tumour and a lesion confined by another structural aspect, the diagnosis of the tumoral aspect of a lesion, the histological ranking in case of glial tumour and the extension of its localization as well as the therapeutic follow-up (pre-therapeutic and post-therapeutics assessments). A better combination between the morphological, functional and metabolic studies, as well as integrating new technical developments, especially while using a multichannel bird cage coils the 3T magnet and suitable computing software, would allow significant improvements of the exploration strategies and management of brain tumors.

  16. Brain tumors induced by radiation in rhesus monkeys

    International Nuclear Information System (INIS)

    Two out of four pubescent rhesus monkeys, which received 1,500 rads of supervoltage X-irradiation, showed malignant brain tumors afer the survival of 52 and 102 weeks each. Since the incidence of spontaneous developing brain tumors in monkeys cited in the literatures was quite low, the tumors in the present series may have been radiation induced. (author)

  17. Regulation of the pituitary tumor transforming gene by insulin-like-growth factor-I and insulin differs between malignant and non-neoplastic astrocytes

    International Nuclear Information System (INIS)

    The reasons for overexpression of the oncogene pituitary tumor transforming gene (PTTG) in tumors are still not fully understood. A possible influence of the insulin-like growth factor I (Igf-I) may be of interest, since enhanced Igf-I signalling was reported in various human tumors. We examined the influence of Igf-I and insulin on PTTG expression in human astrocytoma cells in comparison to proliferating non-neoplastic rat embryonal astrocytes. PTTG mRNA expression and protein levels were increased in malignant astrocytes treated with Igf-I or insulin, whereas in rat embryonic astrocytes PTTG expression and protein levels increased only when cells were exposed to Igf-I. Enhanced transcription did not occur after treatment with inhibitors of phosphoinositol-3-kinase (PI3K) and mitogen-activated protein kinase (MAPK), blocking the two basic signalling pathways of Igf-I and insulin. In addition to this transcriptional regulation, both kinases directly bind to PTTG, suggesting a second regulatory route by phosphorylation. However, the interaction of endogenous PTTG with MAPK and PI3K, as well as PTTG phosphorylation were independent from Igf-I or insulin. The latter results were also found in human testis, which contains high PTTG levels as well as in nonneoplastic astrocytes. This suggest, that PI3K and MAPK signalling is involved in PTTG regulation not only in malignant astrocytomas but also in non-tumorous cells

  18. Photodynamic Therapy for Malignant Brain Tumors.

    Science.gov (United States)

    Akimoto, Jiro

    2016-04-15

    Photodynamic therapy (PDT) using talaporfin sodium together with a semiconductor laser was approved in Japan in October 2003 as a less invasive therapy for early-stage lung cancer. The author believes that the principle of PDT would be applicable for controlling the invading front of malignant brain tumors and verified its efficacy through experiments using glioma cell lines and glioma xenograft models. An investigator-initiated clinical study was jointly conducted with Tokyo Women's Medical University with the support of the Japan Medical Association. Patient enrollment was started in May 2009 and a total of 27 patients were enrolled by March 2012. Of 22 patients included in efficacy analysis, 13 patients with newly diagnosed glioblastoma showed progression-free survival of 12 months, progression-free survival at the site of laser irradiation of 20 months, 1-year survival of 100%, and overall survival of 24.8 months. In addition, the safety analysis of the 27 patients showed that adverse events directly related to PDT were mild. PDT was approved in Japan for health insurance coverage as a new intraoperative therapy with the indication for malignant brain tumors in September 2013. Currently, the post-marketing investigation in the accumulated patients has been conducted, and the preparation of guidelines, holding training courses, and dissemination of information on the safe implementation of PDT using web sites and videos, have been promoted. PDT is expected to be a breakthrough for the treatment of malignant glioma as a tumor cell-selective less invasive therapy for the infiltrated functional brain area. PMID:26888042

  19. Positron Scanner for Locating Brain Tumors

    Science.gov (United States)

    Rankowitz, S.; Robertson, J. S.; Higinbotham, W. A.; Rosenblum, M. J.

    1962-03-01

    A system is described that makes use of positron emitting isotopes for locating brain tumors. This system inherently provides more information about the distribution of radioactivity in the head in less time than existing scanners which use one or two detectors. A stationary circular array of 32 scintillation detectors scans a horizontal layer of the head from many directions simultaneously. The data, consisting of the number of counts in all possible coincidence pairs, are coded and stored in the memory of a Two-Dimensional Pulse-Height Analyzer. A unique method of displaying and interpreting the data is described that enables rapid approximate analysis of complex source distribution patterns. (auth)

  20. Intraoperative MRI in pediatric brain tumors.

    Science.gov (United States)

    Choudhri, Asim F; Siddiqui, Adeel; Klimo, Paul; Boop, Frederick A

    2015-09-01

    Intraoperative magnetic resonance imaging (iMRI) has emerged as an important tool in guiding the surgical management of children with brain tumors. Recent advances have allowed utilization of high field strength systems, including 3-tesla MRI, resulting in diagnostic-quality scans that can be performed while the child is on the operating table. By providing information about the possible presence of residual tumor, it allows the neurosurgeon to both identify and resect any remaining tumor that is thought to be safely accessible. By fusing the newly obtained images with the surgical guidance software, the images have the added value of aiding in navigation to any residual tumor. This is important because parenchyma often shifts during surgery. It also gives the neurosurgeon insight into whether any immediate postoperative complications have occurred. If any complications have occurred, the child is already in the operating room and precious minutes lost in transport and communications are saved. In this article we review the three main approaches to an iMRI system design. We discuss the possible roles for iMRI during intraoperative planning and provide guidance to help radiologists and neurosurgeons alike in the collaborative management of these children. PMID:26346145

  1. Intraoperative MRI in pediatric brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Choudhri, Asim F. [Le Bonheur Children' s Hospital, Department of Radiology, Memphis, TN (United States); University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); University of Tennessee Health Science Center, Department of Neurosurgery, Memphis, TN (United States); University of Tennessee Health Science Center, Department of Ophthalmology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Siddiqui, Adeel [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Klimo, Paul; Boop, Frederick A. [University of Tennessee Health Science Center, Department of Neurosurgery, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Semmes-Murphey Neurologic and Spine Institute, Memphis, TN (United States); St. Jude Children' s Hospital, Division of Neurosurgery, Department of Surgery, Memphis, TN (United States)

    2015-09-15

    Intraoperative magnetic resonance imaging (iMRI) has emerged as an important tool in guiding the surgical management of children with brain tumors. Recent advances have allowed utilization of high field strength systems, including 3-tesla MRI, resulting in diagnostic-quality scans that can be performed while the child is on the operating table. By providing information about the possible presence of residual tumor, it allows the neurosurgeon to both identify and resect any remaining tumor that is thought to be safely accessible. By fusing the newly obtained images with the surgical guidance software, the images have the added value of aiding in navigation to any residual tumor. This is important because parenchyma often shifts during surgery. It also gives the neurosurgeon insight into whether any immediate postoperative complications have occurred. If any complications have occurred, the child is already in the operating room and precious minutes lost in transport and communications are saved. In this article we review the three main approaches to an iMRI system design. We discuss the possible roles for iMRI during intraoperative planning and provide guidance to help radiologists and neurosurgeons alike in the collaborative management of these children. (orig.)

  2. Intraoperative MRI in pediatric brain tumors

    International Nuclear Information System (INIS)

    Intraoperative magnetic resonance imaging (iMRI) has emerged as an important tool in guiding the surgical management of children with brain tumors. Recent advances have allowed utilization of high field strength systems, including 3-tesla MRI, resulting in diagnostic-quality scans that can be performed while the child is on the operating table. By providing information about the possible presence of residual tumor, it allows the neurosurgeon to both identify and resect any remaining tumor that is thought to be safely accessible. By fusing the newly obtained images with the surgical guidance software, the images have the added value of aiding in navigation to any residual tumor. This is important because parenchyma often shifts during surgery. It also gives the neurosurgeon insight into whether any immediate postoperative complications have occurred. If any complications have occurred, the child is already in the operating room and precious minutes lost in transport and communications are saved. In this article we review the three main approaches to an iMRI system design. We discuss the possible roles for iMRI during intraoperative planning and provide guidance to help radiologists and neurosurgeons alike in the collaborative management of these children. (orig.)

  3. Membrane properties and immunohistochemical analyses of astrocytes in post-ischemic rat brain

    Czech Academy of Sciences Publication Activity Database

    Neprašová, Helena; Anděrová, Miroslava; Chvátal, Alexandr; Syková, Eva

    Amsterdam: organizer, 2005. s. 127. [European Meeting on Glial Cell Function in Health and Disease /7./. 17.05.2005-21.05.2005, Amsterdam] R&D Projects: GA ČR(CZ) GA305/03/1172; GA ČR(CZ) GA305/04/1293 Institutional research plan: CEZ:AV0Z50390512 Keywords : astrocyte membrane Subject RIV: FH - Neurology

  4. Astrocyte membrane currents and morphology during hypoosmotic stress and ischemia in brain slices in situ

    Czech Academy of Sciences Publication Activity Database

    Chvátal, Alexandr; Anděrová, Miroslava; Neprašová, Helena; Vargová, Lýdia; Hock, Miroslav; Prajerová, Iva; Chvátal, V.; Syková, Eva

    Amsterdam: organizer, 2005. s. 125. [European Meeting on Glial Cell Function in Health and Disease /7./. 17.05.2005-21.05.2005, Amsterdam] R&D Projects: GA ČR(CZ) GA305/03/1172; GA ČR GA305/04/1293 Institutional research plan: CEZ:AV0Z5039906 Keywords : astrocyte membrane currents Subject RIV: FH - Neurology

  5. Characterization of TEM1/endosialin in human and murine brain tumors

    International Nuclear Information System (INIS)

    TEM1/endosialin is an emerging microvascular marker of tumor angiogenesis. We characterized the expression pattern of TEM1/endosialin in astrocytic and metastatic brain tumors and investigated its role as a therapeutic target in human endothelial cells and mouse xenograft models. In situ hybridization (ISH), immunohistochemistry (IH) and immunofluorescence (IF) were used to localize TEM1/endosialin expression in grade II-IV astrocytomas and metastatic brain tumors on tissue microarrays. Changes in TEM1/endosialin expression in response to pro-angiogenic conditions were assessed in human endothelial cells grown in vitro. Intracranial U87MG glioblastoma (GBM) xenografts were analyzed in nude TEM1/endosialin knockout (KO) and wildtype (WT) mice. TEM1/endosialin was upregulated in primary and metastatic human brain tumors, where it localized primarily to the tumor vasculature and a subset of tumor stromal cells. Analysis of 275 arrayed grade II-IV astrocytomas demonstrated TEM1/endosialin expression in 79% of tumors. Robust TEM1/endosialin expression occurred in 31% of glioblastomas (grade IV astroctyomas). TEM1/endosialin expression was inversely correlated with patient age. TEM1/endosialin showed limited co-localization with CD31, αSMA and fibronectin in clinical specimens. In vitro, TEM1/endosialin was upregulated in human endothelial cells cultured in matrigel. Vascular Tem1/endosialin was induced in intracranial U87MG GBM xenografts grown in mice. Tem1/endosialin KO vs WT mice demonstrated equivalent survival and tumor growth when implanted with intracranial GBM xenografts, although Tem1/endosialin KO tumors were significantly more vascular than the WT counterparts. TEM1/endosialin was induced in the vasculature of high-grade brain tumors where its expression was inversely correlated with patient age. Although lack of TEM1/endosialin did not suppress growth of intracranial GBM xenografts, it did increase tumor vascularity. The cellular localization of TEM1

  6. An integrative view on sex differences in brain tumors

    OpenAIRE

    Sun, Tao; Plutynski, Anya; Ward, Stacey; Rubin, Joshua B.

    2015-01-01

    Sex differences in human health and disease can range from undetectable to profound. Differences in brain tumor rates and outcome are evident in males and females throughout the world and regardless of age. These observations indicate that fundamental aspects of sex determination can impact the biology of brain tumors. It is likely that optimal personalized approaches to the treatment of male and female brain tumor patients will require recognizing and understanding the ways in which the biol...

  7. Increased expression of aquaporin-4 in human traumatic brain injury and brain tumors

    Institute of Scientific and Technical Information of China (English)

    HU Hua; YAO Hong-tian; ZHANG Wei-ping; ZHANG LEI; DING Wei; ZHANG Shi-hong; CHEN Zhong; WEI Er-qing

    2005-01-01

    Objective: To characterize the expression of aquaporin-4 (AQP4), one of the aquaporins (AQPs), in human brain specimens from patients with traumatic brain injury or brain tumors. Methods: Nineteen human brain specimens were obtained from the patients with traumatic brain injury, brain tumors, benign meningioma or early stage hemorrhagic stroke. MRI or CT imaging was used to assess brain edema. Hematoxylin and eosin staining were used to evaluate cell damage. Immunohistochemistry was used to detect the AQP4 expression. Results: AQP4 expression was increased from 15h to at least 8 d after injury. AQP4immunoreactivity was strong around astrocytomas, ganglioglioma and metastatic adenocarcinoma. However, AQP4 immunoreactivity was only found in the centers of astrocytomas and ganglioglioma, but not in metastatic adenocarcinoma derived from lung.Conclusion: AQP4 expression increases in human brains after traumatic brain injury, within brain-derived tumors, and around brain tumors.

  8. Heterogeneity of Astrocytic Form and Function

    OpenAIRE

    Oberheim, Nancy Ann; Goldman, Steven A.; NEDERGAARD, Maiken

    2012-01-01

    Astrocytes participate in all essential CNS functions, including blood flow regulation, energy metabolism, ion and water homeostasis, immune defence, neurotransmission, and adult neurogenesis. It is thus not surprising that astrocytic morphology and function differ between regions, and that different subclasses of astrocytes exist within the same brain region. Recent lines of work also show that the complexity of protoplasmic astrocytes increases during evolution. Human astrocytes are structu...

  9. Marrow Stromal Cells Migrate Throughout Forebrain and Cerebellum, and They Differentiate into Astrocytes after Injection into Neonatal Mouse Brains

    Science.gov (United States)

    Kopen, Gene C.; Prockop, Darwin J.; Phinney, Donald G.

    1999-09-01

    Stem cells are a valuable resource for treating disease, but limited access to stem cells from tissues such as brain restricts their utility. Here, we injected marrow stromal cells (MSCs) into the lateral ventricle of neonatal mice and asked whether these multipotential mesenchymal progenitors from bone marrow can adopt neural cell fates when exposed to the brain microenvironment. By 12 days postinjection, MSCs migrated throughout the forebrain and cerebellum without disruption to the host brain architecture. Some MSCs within the striatum and the molecular layer of the hippocampus expressed glial fibrillary acidic protein and, therefore, differentiated into mature astrocytes. MSCs also populated neuron rich regions including the Islands of Calleja, the olfactory bulb, and the internal granular layer of the cerebellum. A large number of MSCs also were found within the external granular layer of the cerebellum. In addition, neurofilament positive donor cells were found within the reticular formation of the brain stem, suggesting that MSCs also may have differentiated into neurons. Therefore, MSCs are capable of producing differentiated progeny of a different dermal origin after implantation into neonatal mouse brains. These results suggest that MSCs are potentially useful as vectors for treating a variety of central nervous system disorders.

  10. Brain pericytes among cells constituting the blood-brain barrier are highly sensitive to tumor necrosis factor-α, releasing matrix metalloproteinase-9 and migrating in vitro

    Directory of Open Access Journals (Sweden)

    Miyaji Haruki

    2011-08-01

    Full Text Available Abstract Background Increased matrix metalloproteinase (MMP-9 in the plasma and brain is associated with blood-brain barrier (BBB disruption through proteolytic activity in neuroinflammatory diseases. MMP-9 is present in the brain microvasculature and its vicinity, where brain microvascular endothelial cells (BMECs, pericytes and astrocytes constitute the BBB. Little is known about the cellular source and role of MMP-9 at the BBB. Here, we examined the ability of pericytes to release MMP-9 and migrate in response to inflammatory mediators in comparison with BMECs and astrocytes, using primary cultures isolated from rat brains. Methods The culture supernatants were collected from primary cultures of rat brain endothelial cells, pericytes, or astrocytes. MMP-9 activities and levels in the supernatants were measured by gelatin zymography and western blot, respectively. The involvement of signaling molecules including mitogen-activated protein kinases (MAPKs and phosphoinositide-3-kinase (PI3K/Akt in the mediation of tumor necrosis factor (TNF-α-induced MMP-9 release was examined using specific inhibitors. The functional activity of MMP-9 was evaluated by a cell migration assay. Results Zymographic and western blot analyses demonstrated that TNF-α stimulated pericytes to release MMP-9, and this release was much higher than from BMECs or astrocytes. Other inflammatory mediators [interleukin (IL-1β, interferon-γ, IL-6 and lipopolysaccharide] failed to induce MMP-9 release from pericytes. TNF-α-induced MMP-9 release from pericytes was found to be mediated by MAPKs and PI3K. Scratch wound healing assay showed that in contrast to BMECs and astrocytes the extent of pericyte migration was significantly increased by TNF-α. This pericyte migration was inhibited by anti-MMP-9 antibody. Conclusion These findings suggest that pericytes are most sensitive to TNF-α in terms of MMP-9 release, and are the major source of MMP-9 at the BBB. This pericyte

  11. Astrocytes Potentiate Synaptic Transmission

    Science.gov (United States)

    Nadkarni, Suhita

    2005-03-01

    A recent experimental study shows that astrocytes, a subtype of glia, are able to influence the spontaneous activity in the brain via calcium dependent glutamate release. We model the coupling mechanism between an astrocyte and a neuron based on experimental data. This coupling is dynamic and bi-directional, such that the modulations in intracellular calcium concentrations in astrocytes affect neuronal excitability and vice versa via a glutamatergic pathway. We demonstrate through simple neural-glial circuits that increases in the intracellular calcium concentration in astrocytes nearby can enhance spontaneous activity in a neuron, a significant mechanism said to be involved in plasticity and learning. The pattern of this marked increase in spontaneous firing rate in our model quantitatively follows that observed in the experiment. Further, depending on the type of synaptic connections diverging from the neuron, it can either inhibit or excite the ensuing dynamics and potentiate synaptic transmission, thus reinstating the integral role played by astrocytes in normal neuronal dynamics.

  12. Effect of brain-derived neurotropic factor released from hypoxic astrocytes on gamma-aminobutyric acid type A receptor function in normal hippocampal neurons

    Institute of Scientific and Technical Information of China (English)

    Hongliang Liu; Tijun Dai

    2011-01-01

    Astrocytes can release increased levels of brain-derived neurotrophic factor during cerebral ischemia, but it is unclear whether brain-derived neurotrophic factor affects γ-aminobutyric acid type A receptor function in normal neurons. Results from this study demonstrated that γ-aminobutyric acid at 100 μmol/L concentration raised the intracellular calcium level in neurons treated with medium from cultured hypoxic astrocytes, and the rise in calcium level could be inhibited by γ-aminobutyric acid type A receptor antagonist bicuculline or brain-derived neurotrophic factor receptor antagonist k252a. Γ-aminobutyric acid type A-gated current induced by 100 μmol/L γ-aminobutyric acid was in an inward direction in physiological conditions, but shifted to the outward direction in neurons when treated with the medium from cultured hypoxic astrocytes, and this effect could be inhibited by k252a. The reverse potential was shifted leftward to -93 Mv, which could be inhibited by k252a and Na+-K+-Cl- cotransporter inhibitor bumetanide. Brain-derived neurotrophic factor was released from hypoxic astrocytes at a high level. It shifted the reverse potential of γ-aminobutyric acid type A-gated currents leftward in normal neurons by enhancing the function of Na+-K+-Cl- cotransporter, and caused γ-aminobutyric acid to exert an excitatory effect by activating γ-aminobutyric acid type A receptor.

  13. Bifurcation mechanisms of regular and chaotic network signaling in brain astrocytes

    Science.gov (United States)

    Matrosov, V. V.; Kazantsev, V. B.

    2011-06-01

    Bifurcation mechanisms underlying calcium oscillations in the network of astrocytes are investigated. Network model includes the dynamics of intracellular calcium concentration and intercellular diffusion of inositol 1,4,5-trisphosphate through gap junctions. Bifurcation analysis of underlying nonlinear dynamical system is presented. Parameter regions and principle bifurcation boundaries have been delineated and described. We show how variations of the diffusion rate can lead to generation of network calcium oscillations in originally nonoscillating cells. Different scenarios of regular activity and its transitions to chaotic dynamics have been obtained. Then, the bifurcations have been associated with statistical characteristics of calcium signals showing that different bifurcation scenarios yield qualitative changes in experimentally measurable quantities of the astrocyte activity, e.g., statistics of calcium spikes.

  14. Intensity-Modulated Radiation Therapy for Primary Brain Tumors

    Institute of Scientific and Technical Information of China (English)

    Zhong-min Wang

    2004-01-01

    Radiation therapy has been used to treat primary brain tumors as standard primary and/or adjunctive therapies for decades. It is difficult for conventional radiotherapy to deliver a lethal dose of radiation to the tumors while sparing surrounding normal brain due to complicated structures and multifunction in human brain. With the understanding of radiation physics and computer technology, a number of novel and more precise radiotherapies have been developed in recent years. Intensity modulated radiotherapy (IMRT) is one of these strategies. The use of IMRT in the treatment of primary brain tumors is being increasing nowadays. It shows great promise for some of primary brain tumors and also presents some problems, This review highlights current IMRT in the treatment of mainly primary brain tumors.

  15. Malignant gliomas induce and exploit astrocytic mesenchymal-like transition by activating canonical Wnt/β-catenin signaling.

    Science.gov (United States)

    Lu, Ping; Wang, Yajing; Liu, Xiuting; Wang, Hong; Zhang, Xin; Wang, Kequan; Wang, Qing; Hu, Rong

    2016-07-01

    The complex microenvironment of malignant gliomas plays a dynamic and usually cancer-promoting role in glioma progression. Astrocytes, the major stromal cells in the brain, can be activated by glioma microenvironment, resulting in a layer of reactive astrocytes surrounding the gliomas. Reactive astrocytes are universally characterized with the upregulation of glial fibrillary protein and glycoprotein podoplanin. In this work, we investigated the role of reactive astrocytes on malignant glioma microenvironment and the potential mechanism by which glioma cells activated the tumor-associated astrocytes (TAAs). The reactive astrocytes were observed around gliomas in the intracranial syngeneic implantation of rat C6 and mouse GL261 glioma cells in vivo, as well as primary astrocytes cultured with glioma cells condition medium in vitro. Besides, reactive astrocytes exhibited distinct epithelial-to-mesenchymal (-like) transition and enhanced migration and invasion activity, with the decrease of E-cadherin and concomitant increase of vimentin and matrix metalloproteinases. Furthermore, canonical Wnt/β-catenin signaling was activated in TAAs. The Wnt/β-catenin pathway inhibitor XAV939 and β-catenin plasmid were used to verify the regulation of Wnt/β-catenin signaling on TAAs and their invasion ability. Taken together, our findings established that glioma cells remarkably activated astrocytes via upregulating Wnt/β-catenin signaling, with obviously mesenchymal-like transition and increased migration and invasion ability, indicating that glioma cells may stimulate adjacent astrocytes to degrade extracellular matrix and thereby promoting tumor invasiveness. PMID:27236327

  16. Increased expression of aquaporin-4 in human traumatic brain injury and brain tumors

    Institute of Scientific and Technical Information of China (English)

    HuaHu; Wei-PingZhang; LeiZhang; ZhongChen; Er-QingWei

    2004-01-01

    Aquaporin-4 (AQP4) is one of the aquaporins (AQPs), a water channel family. In the brain, AQP4 is expressed in astroeyte foot processes, and plays an important role in water homeostasis and in the formation of brain edema. In our study, AQP4 expression in human brain specimens from patients with traumatic brain injury or different brain tumors was detected

  17. Growth Patterns of Microscopic Brain Tumors

    CERN Document Server

    Sander, L M; Sander, Leonard M.; Deisboeck, Thomas S.

    2002-01-01

    Highly malignant brain tumors such as Glioblastoma Multiforme (GBM) form complex growth patterns in vitro in which invasive cells organize in tenuous branches. Here, we formulate a chemotaxis model for this sort of growth. A key element controlling the pattern is homotype attraction, i.e., the tendency for invasive cells to follow pathways previously explored. We investigate this in two ways: we show that there is an intrinsic instability in the model, which leads to branch formation. We also give a discrete description for the expansion of the invasive zone, and a continuum model for the nutrient supply. The results indicate that both, strong heterotype chemotaxis and strong homotype chemo-attraction are required for branch formation within the invasive zone. Our model thus can give a way to assess the importance of the various processes, and a way to explore and analyze transitions between different growth regimes.

  18. Anticonvulsant therapy in brain-tumor related epilepsy

    Directory of Open Access Journals (Sweden)

    Fröscher Walter

    2016-06-01

    Full Text Available Background. The lifetime risk of patients with brain tumors to have focal epileptic seizures is 10-100%; the risk depends on different histology. Specific guidelines for drug treatment of brain tumor-related seizures have not yet been established.

  19. Interphone study - on mobile phones and brain tumors

    International Nuclear Information System (INIS)

    Interphone study is the largest study on mobile phone use and risk of brain tumors that have been implemented. The study does not provide reliable answers to whether there is an increased risk of brain tumors using the mobile phone, but is an important contribution. (AG)

  20. Transcriptional signature of an adult brain tumor in Drosophila

    Directory of Open Access Journals (Sweden)

    Loop Thomas

    2004-04-01

    Full Text Available Abstract Background Mutations and gene expression alterations in brain tumors have been extensively investigated, however the causes of brain tumorigenesis are largely unknown. Animal models are necessary to correlate altered transcriptional activity and tumor phenotype and to better understand how these alterations cause malignant growth. In order to gain insights into the in vivo transcriptional activity associated with a brain tumor, we carried out genome-wide microarray expression analyses of an adult brain tumor in Drosophila caused by homozygous mutation in the tumor suppressor gene brain tumor (brat. Results Two independent genome-wide gene expression studies using two different oligonucleotide microarray platforms were used to compare the transcriptome of adult wildtype flies with mutants displaying the adult bratk06028 mutant brain tumor. Cross-validation and stringent statistical criteria identified a core transcriptional signature of bratk06028 neoplastic tissue. We find significant expression level changes for 321 annotated genes associated with the adult neoplastic bratk06028 tissue indicating elevated and aberrant metabolic and cell cycle activity, upregulation of the basal transcriptional machinery, as well as elevated and aberrant activity of ribosome synthesis and translation control. One fifth of these genes show homology to known mammalian genes involved in cancer formation. Conclusion Our results identify for the first time the genome-wide transcriptional alterations associated with an adult brain tumor in Drosophila and reveal insights into the possible mechanisms of tumor formation caused by homozygous mutation of the translational repressor brat.

  1. Phorbol 12-myristate 13-acetate induces protein kinase ceta-specific proliferative response in astrocytic tumor cells.

    Science.gov (United States)

    Hussaini, I M; Karns, L R; Vinton, G; Carpenter, J E; Redpath, G T; Sando, J J; VandenBerg, S R

    2000-07-21

    Protein kinase C (PKC) activation has been implicated in cellular proliferation in neoplastic astrocytes. The roles for specific PKC isozymes in regulating this glial response, however, are not well understood. The aim of this study was to characterize the expression of PKC isozymes and the role of PKC-eta expression in regulating cellular proliferation in two well characterized astrocytic tumor cell lines (U-1242 MG and U-251 MG) with different properties of growth in cell culture. Both cell lines expressed an array of conventional (alpha, betaI, betaII, and gamma) and novel (theta and epsilon) PKC isozymes that can be activated by phorbol myristate acetate (PMA). Another novel PKC isozyme, PKC-eta, was only expressed by U-251 MG cells. In contrast, PKC-delta was readily detected in U-1242 MG cells but was present only at low levels in U-251 MG cells. PMA (100 nm) treatment for 24 h increased cell proliferation by over 2-fold in the U-251 MG cells, whereas it decreased the mitogenic response in the U-1242 MG cells by over 90%. When PKC-eta was stably transfected into U-1242 MG cells, PMA increased cell proliferation by 2.2-fold, similar to the response of U-251 MG cells. The cell proliferation induced by PMA in both the U-251 MG and U-1242-PKC-eta cells was blocked by the PKC inhibitor bisindolylmaleimide (0.5 micrometer) and the MEK inhibitor, PD 98059 (50 micrometer). Transient transfection of wild type U-251 with PKC-eta antisense oligonucleotide (1 micrometer) also blocked the PMA-induced increase in [(3)H]thymidine incorporation. The data demonstrate that two glioblastoma lines, with functionally distinct proliferative responses to PMA, express different novel PKC isozymes and that the differential expression of PKC-eta plays a determining role in the different proliferative capacity. PMID:10806212

  2. Preliminary study of MR elastography in brain tumors

    International Nuclear Information System (INIS)

    Objective: To investigate the potential values of magnetic resonance elastography (MRE) for evaluating the brain tumor consistency in vivo. Methods: Fourteen patients with known solid brain tumor (5 male, 9 female; age range: 16-63 years) underwent brain MRE studies. Informed consent was obtained from all patients. A dedicated external force actuator for brain MRE study was developed. The actuator was fixed to the head coil. During scan, one side of the actuator was attached to the patients' head. Low frequency oscillation was produced by the actuator and caused shear waves propagating into brain tissue. The pulse sequence used in the study was phase-contrast gradient-echo sequence. Phase images of the brain were obtained and the shear waves within the brain were directly imaged. Phase images were processed with local frequency estimation (LFE) technique to obtain the elasticity image. Consistency of brain tumors was evaluated at surgery and was classified as soft, intermediate, or hard with comparison to the white matter of the brain. Correspondence of MRE evaluation with operative results was studied. Results: The elastic modulus of the tumor was lower than that of white matter in 1 patient, higher in 11 patients, and similar in 2 patients. At surgery, the tumor manifested a soft consistency in 1 patient, hard consistency in 11 patients, intermediate consistency in 2 patients. The elasticity of tumors in 14 patients evaluated by MRE was correlated with the tumor consistency on the operation. Conclusion: MRE can noninvasively display the elasticity of brain tumors in vivo, and evaluate the brain tumor consistency before operation. (authors)

  3. A study of ICAM expression in brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Hoon; Lee, Seung Hoon; Hong, Seok Il [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1995-12-01

    The purpose of this study is to test the possibility of using sICAM-1 as a marker for follow-up of treatment. The micro-ELISA method was adopted. The brain stem gliomas showed positive results in 67%. Overall, 23% of brain tumors showed positive results. It is possible that we can use sICAM-1 as a marker for metastatic brain tumors, and measurement after radiation therapy is not reliable. 6 refs. (Author) (Author).

  4. Comparison of Swallowing Functions Between Brain Tumor and Stroke Patients

    OpenAIRE

    Park, Dae Hwan; Chun, Min Ho; Lee, Sook Joung; Song, Yoon Bum

    2013-01-01

    Objective To compare the swallowing functions according to the lesion locations between brain tumor and stroke patients. Methods Forty brain tumor patients and the same number of age-, lesion-, and functional status-matching stroke patients were enrolled in this study. Before beginning the swallowing therapy, swallowing function was evaluated in all subjects by videofluoroscopic swallowing study. Brain lesions were classified as either supratentorial or in-fratentorial. We evaluated the follo...

  5. Brain Tumor Detection Based On Mathematical Analysis and Symmetry Information

    OpenAIRE

    G., Narkhede Sachin; Khairnar, Vaishali; Kadu, Sujata

    2014-01-01

    Image segmentation some of the challenging issues on brain magnetic resonance image tumor segmentation caused by the weak correlation between magnetic resonance imaging intensity and anatomical meaning.With the objective of utilizing more meaningful information to improve brain tumor segmentation,an approach which employs bilateral symmetry information as an additional feature for segmentation is proposed.This is motivated by potential performance improvement in the general automatic brain tu...

  6. Yoga Therapy in Treating Patients With Malignant Brain Tumors

    Science.gov (United States)

    2015-07-27

    Adult Anaplastic Astrocytoma; Adult Anaplastic Ependymoma; Adult Anaplastic Meningioma; Adult Anaplastic Oligodendroglioma; Adult Brain Stem Glioma; Adult Choroid Plexus Tumor; Adult Diffuse Astrocytoma; Adult Ependymoblastoma; Adult Ependymoma; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Grade II Meningioma; Adult Medulloblastoma; Adult Meningeal Hemangiopericytoma; Adult Mixed Glioma; Adult Oligodendroglioma; Adult Papillary Meningioma; Adult Pineal Gland Astrocytoma; Adult Pineoblastoma; Adult Pineocytoma; Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Recurrent Adult Brain Tumor

  7. Extracellular signal regulated kinases 1/2 signal pathway and responses of astrocytes after diffuse brain injury

    Institute of Scientific and Technical Information of China (English)

    Jinxing Li; Haimei Zhao; Yu Li; Chong Wang; Jiashan Zhao; Xianli Zhu

    2007-01-01

    BACKGROUND: The treatment of diffuse brain injury during an acute period is focused on relieving degrees of secondary brain injury. Generation and development of pathological changes of secondary brain injury depend on signal conduction, so down-regulating over response of astrocyte through interfering a key link of signal conduction pathway may bring a new thinking for the treatment of diffuse brain injury. OBJECTIVE: To observe the effect of over activity of extracellular signal regulated kinases 1/2 (ERK1/2) signal pathway on the response of astrocyte during an acute period of diffuse brain injury. DESIGN: Completely randomized grouping and controlled animal study.SETTINGS: Department of Neurosurgery, the Third Affiliated Hospital, Nanchang University; Department of Neurosurgery, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology.MATERIALS: A total of 158 healthy male SD rats, of 11 weeks old, weighing 320 - 370 g, were provided by Experimental Animal Faulty, Tongji Medical College, Huazhong University of Science and Technology. Rabbit-anti-phosphorylated ERK1/2 (pERKl/2) polyclonal antibody was provided by R&D Company; rabbit-anti-glial fibrillary acidic protein (GFAP) polyclonal antibody, SP immunohistochemical kit and horseradish peroxidase (HRP)-labeled goat-anti-rabbit IgG by Santa Cruz Company; specific inhibitor U0126 of ERK1/2 signal pathway by Alexis Company. METHODS: The experiment was carried out in the Laboratory of Neurosurgery, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology from September 2004 to March 2006. ①Detection of pERKl/2 expression: A total of 110 rats were randomly divided into sham operation group (n =5), model group (n =35), high-dosage U0126 group (n =35) and low-dosage U0126 group (n =35). Rats in the sham operation group were only treated with incision of epicranium and fixation of backup plate, but not hit. Rats in the model group

  8. The relationship of bone-tumor-induced spinal cord astrocyte activation and aromatase expression to mechanical hyperalgesia and cold hypersensitivity in intact female and ovariectomized mice.

    Science.gov (United States)

    Smeester, B A; O'Brien, E E; Michlitsch, K S; Lee, J-H; Beitz, A J

    2016-06-01

    Recently, our group established a relationship between tumor-induced spinal cord astrocyte activation and aromatase expression and the development of bone tumor nociception in male mice. As an extension of this work, we now report on the association of tumor-induced mechanical hyperalgesia and cold hypersensitivity to changes in spinal cord dorsal horn GFAP and aromatase expression in intact (INT) female mice and the effect of ovariectomy on these parameters. Implantation of fibrosarcoma cells produced robust mechanical hyperalgesia in INT animals, while ovariectomized (OVX) females had significantly less mechanical hyperalgesia. Cold hypersensitivity was apparent by post-implantation day 7 in INT and OVX females compared to their saline-injected controls and increased throughout the experiment. The decrease in mechanical hyperalgesia in OVX females was mirrored by significant decreases in spinal astrocyte activity in laminae I-II, III-IV, V-VI and X and aromatase expression in laminae V-VI and X in the dorsal horn of tumor-bearing animals. Administration of the aromatase inhibitor letrozole reduced tumor-induced hyperalgesia in INT females only suggesting that the tumor-induced increase in aromatase expression and its associated increase in spinal estrogen play a role in the development of bone tumor-induced hyperalgesia. Finally, intrathecal (i.t.) administration of 17β-estradiol caused a significant increase in tumor-induced hyperalgesia in INT tumor-bearing females. Since i.t. 17β-estradiol increases tumor pain and ovariectomy significantly decreases tumor pain, as well as spinal aromatase, estrogen may play a critical role in the spinal cord response to the changing tumor environment and the development of tumor-induced nociception. PMID:26995084

  9. Research on Perfusion CT in Rabbit Brain Tumor Model

    International Nuclear Information System (INIS)

    We investigated the vascular characteristics of tumors and normal tissue using perfusion CT in the rabbit brain tumor model. The VX2 carcinoma concentration of 1 x 107 cells/ml(0.1 ml) was implanted in the brain of nine New Zealand white rabbits (weight: 2.4 kg-3.0 kg, mean: 2.6 kg). The perfusion CT was scanned when the tumors were grown up to 5 mm. The tumor volume and perfusion value were quantitatively analyzed by using commercial workstation (advantage windows workstation, AW, version 4.2, GE, USA). The mean volume of implanted tumors was 316±181 mm3, and the biggest and smallest volumes of tumor were 497 mm3 and 195 mm3, respectively. All the implanted tumors in rabbits are single-nodular tumors, and intracranial metastasis was not observed. In the perfusion CT, cerebral blood volume (CBV) were 74.40±9.63, 16.8±0.64, 15.24±3.23 ml/100g in the tumor core, ipsilateral normal brain, and contralateral normal brain, respectively (p≤0.05). In the cerebral blood flow (CBF), there were significant differences between the tumor core and both normal brains (p≤0.05), but no significant differences between ipsilateral and contralateral normal brains (962.91±75.96 vs. 357.82±12.82 vs. 323.19±83.24 ml/100g/min). In the mean transit time (MTT), there were significant differences between the tumor core and both normal brains (p≤0.05), but no significant differences between ipsilateral and contralateral normal brains (4.37±0.19 vs. 3.02±0.41 vs. 2.86±0.22 sec). In the permeability surface (PS), there were significant differences among the tumor core, ipsilateral and contralateral normal brains (47.23±25.44 vs. 14.54±1.60 vs. 6.81±4.20 ml/100g/min)(p≤0.05). In the time to peak (TTP) were no significant differences among the tumor core, ipsilateral and contralateral normal brains. In the positive enhancement integral (PEI), there were significant differences among the tumor core, ipsilateral and contralateral brains (61.56±16.07 vs. 12.58±2.61 vs. 8.26±5

  10. Research on Perfusion CT in Rabbit Brain Tumor Model

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Bon Chul; Kwak, Byung Kook; Jung, Ji Sung [Dept. of Diagnostic Radiology, Chung Ang University Hospital, Seoul (Korea, Republic of); Lim, Cheong Hwan; Jung, Hong Ryang [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of)

    2012-06-15

    We investigated the vascular characteristics of tumors and normal tissue using perfusion CT in the rabbit brain tumor model. The VX2 carcinoma concentration of 1 x 10{sup 7} cells/ml(0.1 ml) was implanted in the brain of nine New Zealand white rabbits (weight: 2.4 kg-3.0 kg, mean: 2.6 kg). The perfusion CT was scanned when the tumors were grown up to 5 mm. The tumor volume and perfusion value were quantitatively analyzed by using commercial workstation (advantage windows workstation, AW, version 4.2, GE, USA). The mean volume of implanted tumors was 316{+-}181 mm{sup 3}, and the biggest and smallest volumes of tumor were 497 mm{sup 3} and 195 mm{sup 3}, respectively. All the implanted tumors in rabbits are single-nodular tumors, and intracranial metastasis was not observed. In the perfusion CT, cerebral blood volume (CBV) were 74.40{+-}9.63, 16.8{+-}0.64, 15.24{+-}3.23 ml/100g in the tumor core, ipsilateral normal brain, and contralateral normal brain, respectively (p{<=}0.05). In the cerebral blood flow (CBF), there were significant differences between the tumor core and both normal brains (p{<=}0.05), but no significant differences between ipsilateral and contralateral normal brains (962.91{+-}75.96 vs. 357.82{+-}12.82 vs. 323.19{+-}83.24 ml/100g/min). In the mean transit time (MTT), there were significant differences between the tumor core and both normal brains (p{<=}0.05), but no significant differences between ipsilateral and contralateral normal brains (4.37{+-}0.19 vs. 3.02{+-}0.41 vs. 2.86{+-}0.22 sec). In the permeability surface (PS), there were significant differences among the tumor core, ipsilateral and contralateral normal brains (47.23{+-}25.44 vs. 14.54{+-}1.60 vs. 6.81{+-}4.20 ml/100g/min)(p{<=}0.05). In the time to peak (TTP) were no significant differences among the tumor core, ipsilateral and contralateral normal brains. In the positive enhancement integral (PEI), there were significant differences among the tumor core, ipsilateral and

  11. Blood Brain Barrier: A Challenge for Effectual Therapy of Brain Tumors

    OpenAIRE

    Arijit Bhowmik; Rajni Khan; Mrinal Kanti Ghosh

    2015-01-01

    Brain tumors are one of the most formidable diseases of mankind. They have only a fair to poor prognosis and high relapse rate. One of the major causes of extreme difficulty in brain tumor treatment is the presence of blood brain barrier (BBB). BBB comprises different molecular components and transport systems, which in turn create efflux machinery or hindrance for the entry of several drugs in brain. Thus, along with the conventional techniques, successful modification of drug delivery and n...

  12. Brain-derived neurotrophic factor protects neurons from GdCl3-induced impairment in neuron-astrocyte co-cultures

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Gadolinium (Gd3+) complexes are important contrast agents in medical magnetic resonance imaging (MRI) and of great potential value in brain research. In order to better understand the mechanisms of the action of Gd3+ on neurons in the complex central nervous system (CNS), the neurotoxic actions of GdCl3 have been investigated in both neuron monoculture and astrocyte-neuron co-culture systems. Measurements of lactate dehydrogenase release showed that GdCl3 causes significant cell death of monocultured neurons as a result of reactive oxygen species (ROS) generation and down-regulation of brain-derived neurotrophic factor (BDNF). However, GdCl3 does not affect the viability and BDNF expression of astrocytes. Both co-culturing of neurons with astrocytes and addition of BDNF ameliorated GdCl3-induced neurotoxicity by decreasing ROS generation and facilitating recovery of BDNF levels. The results obtained suggest that astrocytes in the CNS may protect neurons from GdCl3-induced impairment through secreting BDNF and thus up-regulating BDNF expression and interfering with Gd3+-induced cell signaling in neurons. A possible molecular mechanism is suggested which should be helpful in understand- ing the neurotoxic actions of gadolinium probes .

  13. A three-dimensional model of the human blood-brain barrier to analyse the transport of nanoparticles and astrocyte/endothelial interactions [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Peddagangannagari Sreekanthreddy

    2016-01-01

    Full Text Available The aim of this study was to develop a three-dimensional (3D model of the human blood-brain barrier in vitro, which mimics the cellular architecture of the CNS and could be used to analyse the delivery of nanoparticles to cells of the CNS. The model includes human astrocytes set in a collagen gel, which is overlaid by a monolayer of human brain endothelium (hCMEC/D3 cell line. The model was characterised by transmission electron microscopy (TEM, immunofluorescence microscopy and flow cytometry. A collagenase digestion method could recover the two cell types separately at 92-96% purity.  Astrocytes grown in the gel matrix do not divide and they have reduced expression of aquaporin-4 and the endothelin receptor, type B compared to two-dimensional cultures, but maintain their expression of glial fibrillary acidic protein. The effects of conditioned media from these astrocytes on the barrier phenotype of the endothelium was compared with media from astrocytes grown conventionally on a two-dimensional (2D substratum. Both induce the expression of tight junction proteins zonula occludens-1 and claudin-5 in hCMEC/D3 cells, but there was no difference between the induced expression levels by the two media. The model has been used to assess the transport of glucose-coated 4nm gold nanoparticles and for leukocyte migration. TEM was used to trace and quantitate the movement of the nanoparticles across the endothelium and into the astrocytes. This blood-brain barrier model is very suitable for assessing delivery of nanoparticles and larger biomolecules to cells of the CNS, following transport across the endothelium.

  14. High Toxoplasma gondii Seropositivity among Brain Tumor Patients in Korea

    Science.gov (United States)

    Jung, Bong-Kwang; Song, Hyemi; Kim, Min-Jae; Cho, Jaeeun; Shin, Eun-Hee; Chai, Jong-Yil

    2016-01-01

    Toxoplasma gondii is an intracellular protozoan that can modulate the environment of the infected host. An unfavorable environment modulated by T. gondii in the brain includes tumor microenvironment. Literature has suggested that T. gondii infection is associated with development of brain tumors. However, in Korea, epidemiological data regarding this correlation have been scarce. In this study, in order to investigate the relationship between T. gondii infection and brain tumor development, we investigated the seroprevalence of T. gondii among 93 confirmed brain tumor patients (various histological types, including meningioma and astrocytoma) in Korea using ELISA. The results revealed that T. gondii seropositivity among brain tumor patients (18.3%) was significantly (P<0.05) higher compared with that of healthy controls (8.6%). The seropositivity of brain tumor patients showed a significant age-tendency, i.e., higher in younger age group, compared with age-matched healthy controls (P<0.05). In conclusion, this study supports the close relationship between T. gondii infection and incidence of brain tumors. PMID:27180580

  15. Absence of pathogenic mitochondrial DNA mutations in mouse brain tumors

    International Nuclear Information System (INIS)

    Somatic mutations in the mitochondrial genome occur in numerous tumor types including brain tumors. These mutations are generally found in the hypervariable regions I and II of the displacement loop and unlikely alter mitochondrial function. Two hypervariable regions of mononucleotide repeats occur in the mouse mitochondrial genome, i.e., the origin of replication of the light strand (OL) and the Arg tRNA. In this study we examined the entire mitochondrial genome in a series of chemically induced brain tumors in the C57BL/6J strain and spontaneous brain tumors in the VM mouse strain. The tumor mtDNA was compared to that of mtDNA in brain mitochondrial populations from the corresponding syngeneic mouse host strain. Direct sequencing revealed a few homoplasmic base pair insertions, deletions, and substitutions in the tumor cells mainly in regions of mononucleotide repeats. A heteroplasmic mutation in the 16srRNA gene was detected in a spontaneous metastatic VM brain tumor. None of the mutations were considered pathogenic, indicating that mtDNA somatic mutations do not likely contribute to the initiation or progression of these diverse mouse brain tumors

  16. Absence of pathogenic mitochondrial DNA mutations in mouse brain tumors

    Directory of Open Access Journals (Sweden)

    Seyfried Thomas N

    2005-08-01

    Full Text Available Abstract Background Somatic mutations in the mitochondrial genome occur in numerous tumor types including brain tumors. These mutations are generally found in the hypervariable regions I and II of the displacement loop and unlikely alter mitochondrial function. Two hypervariable regions of mononucleotide repeats occur in the mouse mitochondrial genome, i.e., the origin of replication of the light strand (OL and the Arg tRNA. Methods In this study we examined the entire mitochondrial genome in a series of chemically induced brain tumors in the C57BL/6J strain and spontaneous brain tumors in the VM mouse strain. The tumor mtDNA was compared to that of mtDNA in brain mitochondrial populations from the corresponding syngeneic mouse host strain. Results Direct sequencing revealed a few homoplasmic base pair insertions, deletions, and substitutions in the tumor cells mainly in regions of mononucleotide repeats. A heteroplasmic mutation in the 16srRNA gene was detected in a spontaneous metastatic VM brain tumor. Conclusion None of the mutations were considered pathogenic, indicating that mtDNA somatic mutations do not likely contribute to the initiation or progression of these diverse mouse brain tumors.

  17. In vitro model of the blood-brain barrier established by co-culture of primary cerebral microvascular endothelial and astrocyte cells

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2015-01-01

    Full Text Available Drugs for the treatment and prevention of nervous system diseases must permeate the blood-brain barrier to take effect. In vitro models of the blood-brain barrier are therefore important in the investigation of drug permeation mechanisms. However, to date, no unified method has been described for establishing a blood-brain barrier model. Here, we modified an in vitro model of the blood-brain barrier by seeding brain microvascular endothelial cells and astrocytes from newborn rats on a polyester Transwell cell culture membrane with 0.4-µm pores, and conducted transepithelial electrical resistance measurements, leakage tests and assays for specific blood-brain barrier enzymes. We show that the permeability of our model is as low as that of the blood-brain barrier in vivo. Our model will be a valuable tool in the study of the mechanisms of action of neuroprotective drugs.

  18. MAO-B elevation in mouse brain astrocytes results in Parkinson's pathology.

    Directory of Open Access Journals (Sweden)

    Jyothi K Mallajosyula

    Full Text Available Age-related increases in monoamine oxidase B (MAO-B may contribute to neurodegeneration associated with Parkinson's disease (PD. The MAO-B inhibitor deprenyl, a long-standing antiparkinsonian therapy, is currently used clinically in concert with the dopamine precursor L-DOPA. Clinical studies suggesting that deprenyl treatment alone is not protective against PD associated mortality were targeted to symptomatic patients. However, dopamine loss is at least 60% by the time PD is symptomatically detectable, therefore lack of effect of MAO-B inhibition in these patients does not negate a role for MAO-B in pre-symptomatic dopaminergic loss. In order to directly evaluate the role of age-related elevations in astroglial MAO-B in the early initiation or progression of PD, we created genetically engineered transgenic mice in which MAO-B levels could be specifically induced within astroglia in adult animals. Elevated astrocytic MAO-B mimicking age related increase resulted in specific, selective and progressive loss of dopaminergic neurons in the substantia nigra (SN, the same subset of neurons primarily impacted in the human condition. This was accompanied by other PD-related alterations including selective decreases in mitochondrial complex I activity and increased mitochondrial oxidative stress. Along with a global astrogliosis, we observed local microglial activation within the SN. These pathologies correlated with decreased locomotor activity. Importantly, these events occurred even in the absence of the PD-inducing neurotoxin MPTP. Our data demonstrates that elevation of murine astrocytic MAO-B by itself can induce several phenotypes of PD, signifying that MAO-B could be directly involved in multiple aspects of disease neuropathology. Mechanistically this may involve increases in membrane permeant H(2O(2 which can oxidize dopamine within dopaminergic neurons to dopaminochrome which, via interaction with mitochondrial complex I, can result in

  19. Pituitary Tumors

    Science.gov (United States)

    ... Tumors Oligoastrocytoma Oligodendroglioma Pineal Tumor Pituitary Tumor PNET Schwannoma Risk Factors Brain Tumor Facts Brain Tumor Dictionary ... Tumors Oligoastrocytoma Oligodendroglioma Pineal Tumor Pituitary Tumor PNET Schwannoma Risk Factors Brain Tumor Facts Brain Tumor Dictionary ...

  20. Clinicopathological analysis of unusual rosette-forming glioneuronal tumor in brain parenchyma

    Directory of Open Access Journals (Sweden)

    Da-wei LIU

    2014-03-01

    Full Text Available Background Rosette-forming glioneuronal tumor (RGNT is a rare and novel brain tumor. It affects mainly young adults and arises in the midline, primarily involving the cerebellum, and the walls or floor of the fourth ventricle. The tumor is composed of distinctive histological components, uniform neurocytes forming rosettes and (or perivascular pseudorosettes, as well as astrocytic component resembling pilocytic astrocytoma. To our best knowledge, no more than 50 cases of RGNT have been described in the literatures to date and found commonly in association with the ventricular system. Only a few cases have been known to occur at sites outside of its usual location. Herein, we present a rare case of RGNT of brain parenchyma. Due to its rarity and non-specific appearance in radiological examination, it is a diagnostic challenge for radiologists and histopathologists to differentiate RGNT in unusual sites from other intracranial lesions because of its similarities in radiological and histological findings. The aim of this study is to summarize the clinicopathological features of RGNT and discuss the differential diagnosis of histologically similar tumors in brain.  Methods The clinical manifestation of a patient with RGNT occurring in left frontal lobe was presented retrospectively. Resected mass was routinely paraffin-embedded and stained with Hematoxylin and Eosin. Dako EnVision immunohistochemical staining system was used to detect the tumor antigen expressions, including glial fibrillary acidic protein (GFAP, S-100 protein (S-100, cytokeratin (CK, neuronal nuclear antigen (NeuN, synaptophysin (Syn, neuron-specific enolase (NSE, chromogranin A (CgA, oligodendrocytes transcription factor-2 (Olig-2, epithelial membrane antigen (EMA and Ki-67 (MIB-1.  Results A 12-year-old girl presented with 2-year history of twitches and mild headache. MRI revealed a solid well-circumscribed lesion in left frontal lobe with mild heterogeneous enhancement. The

  1. Computational modeling of brain tumors: discrete, continuum or hybrid?

    Science.gov (United States)

    Wang, Zhihui; Deisboeck, Thomas S.

    In spite of all efforts, patients diagnosed with highly malignant brain tumors (gliomas), continue to face a grim prognosis. Achieving significant therapeutic advances will also require a more detailed quantitative understanding of the dynamic interactions among tumor cells, and between these cells and their biological microenvironment. Data-driven computational brain tumor models have the potential to provide experimental tumor biologists with such quantitative and cost-efficient tools to generate and test hypotheses on tumor progression, and to infer fundamental operating principles governing bidirectional signal propagation in multicellular cancer systems. This review highlights the modeling objectives of and challenges with developing such in silico brain tumor models by outlining two distinct computational approaches: discrete and continuum, each with representative examples. Future directions of this integrative computational neuro-oncology field, such as hybrid multiscale multiresolution modeling are discussed.

  2. Truncated N-terminal huntingtin fragment with expanded-polyglutamine (htt552-100Q)suppresses brain-derived neurotrophic factor transcription in astrocytes

    Institute of Scientific and Technical Information of China (English)

    Linhui Wang; Fang Lin; Jin Wang; Junchao Wu; Rong Han; Lujia Zhu; Guoxing Zhang; Marian DiFiglia; Zhenghong Qin

    2012-01-01

    Although huntingtin (htt) can be cleaved at many sites by caspases,calpains,and aspartyl proteases,amino acid (aa) 552 was defined as a preferred site for cleavage in human Huntington disease (HD) brains in vivo.To date,the normal function of wild-type N-terminal htt fragment 1-552 aa (htt552) and its pathological roles of mutant htt552 are still unknown.Although mutant htt (mhtt) is also expressed in astrocytes,whether and how mhtt contributes to the neurodegeneration through astrocytes in HD remains largely unknown.In this study,a glia HD model,using an adenoviral vector to express wild-type htt552 (htt552-18Q) and its mutation (htt552-100Q) in rat primary cortical astrocytes,was generated to investigate the influence of htt552 on the transcription of brainderived neurotrophic factor (BDNF). Results from enzyme linked immunosorbent assay showed that the level of BDNF in astrocyte-conditioned medium was decreased in the astrocytes expressing htt552-100Q.Quantitative real-time polymerase chain reaction demonstrated that htt552-100Q reduced the transcripts of the BDNF Ⅲ and Ⅳ, hence, repressed the transcription of BDNF.Furthermore,immunofluorescence showed that aggregates formed by htt552-100Q entrapped transcription factors cAMP-response element-binding protein and stimulatory protein 1,which might account for the reduction of BDNF transcription.These findings suggest that mhtt552 reduces BDNF transcription in astrocytes,which might contribute to the neuronal dysfunction in HD.

  3. Topoisomerase II alpha and p27; alternative markers to decide on the proliferation capacity of astrocytic tumors

    Directory of Open Access Journals (Sweden)

    Evrim ÖZTÜRK

    2008-05-01

    Full Text Available Proliferation capacity is an important parameter which enables us to predict the prognosis of tumours. Many immunohistochemical studies were conducted to search the relation of proliferative capacity with different clinical and histological parameters. Ki67 is a well known immunohistochemical marker of proliferation and some standard values have been established for Ki67 indexes of astrocytic tumours. For this purpose, considering the roles of proteins in cell cycle, some immunohistochemical markers other than Ki67 can be suggested. In this study, expressions of topoisomerase II alpha, a nuclear protein in mitotically active cells and p27, a cylin-dependent kinase inhibitor, were correlated with the grade and Ki67 indexes of 67 astrocytomas. Topoisomerase expressions demonstrated an increase with increasing grade. It also followed a parallel curve with Ki67. On the other hand, p27 had an inverse correlation with the tumor grade. The cut-off value for topoisomerase was calculated to vary 3.5% between low and high grade tumours. No cut-off value could be obtained for p27.

  4. Cilengitide in Treating Children With Refractory Primary Brain Tumors

    Science.gov (United States)

    2013-09-27

    Childhood Central Nervous System Germ Cell Tumor; Childhood Choroid Plexus Tumor; Childhood Craniopharyngioma; Childhood Ependymoblastoma; Childhood Grade I Meningioma; Childhood Grade II Meningioma; Childhood Grade III Meningioma; Childhood High-grade Cerebellar Astrocytoma; Childhood High-grade Cerebral Astrocytoma; Childhood Infratentorial Ependymoma; Childhood Low-grade Cerebellar Astrocytoma; Childhood Low-grade Cerebral Astrocytoma; Childhood Medulloepithelioma; Childhood Mixed Glioma; Childhood Oligodendroglioma; Childhood Supratentorial Ependymoma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Brain Tumor; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Subependymal Giant Cell Astrocytoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma

  5. Application of 31P MR spectroscopy to the brain tumors

    International Nuclear Information System (INIS)

    To evaluate the clinical feasibility and obtain useful parameters of 31P magnetic resonance spectroscopy (MRS) study for making the differential diagnosis of brain tumors. Twenty-eight patients with brain tumorous lesions (22 cases of brain tumor and 6 cases of abscess) and 11 normal volunteers were included. The patients were classified into the astrocytoma group, lymphoma group, metastasis group and the abscess group. We obtained the intracellular pH and the metabolite ratios of phosphomonoesters/phosophodiesters (PME/PDE), PME/inorganic phosphate (Pi), PDE/Pi, PME/adenosine triphosphate (ATP), PDE/ATP, PME/phosphocreatine (PCr), PDE/PCr, PCr/ATP, PCr/Pi, and ATP/Pi, and evaluated the statistical significances. The brain tumors had a tendency of alkalization (pH = 7.28 ± 0.27, p = 0.090), especially the pH of the lymphoma was significantly increased (pH = 7.45 ± 0.32, p = 0.013). The brain tumor group showed increased PME/PDE ratio compared with that in the normal control group (p 0.012). The ratios of PME/PDE, PDE/Pi, PME/PCr and PDE/PCr showed statistically significant differences between each brain lesion groups (p 1'P MRS, and the pH, PME/PDE, PDE/Pi, PME/PCr, and PDE/PCr ratios are helpful for differentiating among the different types of brain tumors.

  6. Somatostatin receptor scintigraphy in brain tumors and pituitary tumors: First experiences

    International Nuclear Information System (INIS)

    This preliminary study embraced 45 patients with meningiomas, brain tumors or pituitary tumors, which were imaged by planar and tomographic scintigraphy after intravenous injection of 111Indium-labeled octreotide. In all of the meningiomas studied (unifocal and multifocal tumors in various locations), a high density of somatostatin receptors was detected by scintigraphy. Pituitary tumors were slightly positive in 50% of cases only, independent of the endocrine activity. Gliomas with an intact blood-brain barrier showed no enhanced tracer uptake in vivo, while gliomas with distributed blood-brain barrier had a high activity uptake. We conclude that in vivo somatostatin receptor scintigraphy, although not tumor-specific, may aid in the preoperative diagnosis and staging of intracranial tumors, especially skull base tumors. (orig.)

  7. Cortical Plasticity in the Setting of Brain Tumors.

    Science.gov (United States)

    Fisicaro, Ryan A; Jost, Ethan; Shaw, Katharina; Brennan, Nicole Petrovich; Peck, Kyung K; Holodny, Andrei I

    2016-02-01

    Cortical reorganization of function due to the growth of an adjacent brain tumor has clearly been demonstrated in a number of surgically proven cases. Such cases demonstrate the unmistakable implications for the neurosurgical treatment of brain tumors, as the cortical function may not reside where one may initially suspect based solely on the anatomical magnetic resonance imaging (MRI). Consequently, preoperative localization of eloquent areas adjacent to a brain tumor is necessary, as this may demonstrate unexpected organization, which may affect the neurosurgical approach to the lesion. However, in interpreting functional MRI studies, the interpreting physician must be cognizant of artifacts, which may limit the accuracy of functional MRI in the setting of brain tumors. PMID:26848558

  8. Imaging of brain tumors with histological correlations. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Drevelegas, Antonios (ed.)

    2011-07-01

    This volume provides a deeper understanding of the diagnosis of brain tumors by correlating radiographic imaging features with the underlying pathological abnormalities. All modern imaging modalities are used to complete a diagnostic overview of brain tumors with emphasis on recent advances in diagnostic neuroradiology. High-quality illustrations depicting common and uncommon imaging characteristics of a wide range of brain tumors are presented and analysed, drawing attention to the ways in which these characteristics reflect different aspects of pathology. Important theoretical considerations are also discussed. Since the first edition, chapters have been revised and updated and new material has been added, including detailed information on the clinical application of functional MRI and diffusion tensor imaging. Radiologists and other clinicians interested in the current diagnostic approach to brain tumors will find this book to be an invaluable and enlightening clinical tool. (orig.)

  9. Childhood exposure to ionizing radiation and brain tumors

    International Nuclear Information System (INIS)

    Brain has been categorized into the low risk group of radiogenic tumors. However, recent epidemiologic studies on the cancer risks among children who received repeated CT scans, radiotherapies and A-bomb have revealed that low-to-moderate dose of ionizing radiation is effective to induce brain tumors. Ionizing radiation is more strongly associated with risk for meningiomas and schwannomas compared to gliomas. While risk of meningiomas is independent of age at the time of exposure, that of gliomas is profoundly high after neonatal and infantile exposures. Inherited susceptibility to brain tumors is suggested by family history or cancer prone syndromes. People with certain gene mutations such as RB, NF1 or PTCH1 are associated with enhanced cancer risk after radiotherapies. Genetic polymorphism of cancer-related genes on brain tumor risk deserves further investigation. (author)

  10. Clinical results of BNCT for malignant brain tumors in children

    International Nuclear Information System (INIS)

    It is very difficult to treat the patients with malignant brain tumor in children, especially under 3 years, because the conventional irradiation cannot be applied due to the damage of normal brain tissue. However, boron neutron capture therapy (BNCT) has tumor selectivity such that it can make damage only in tumor cells. We evaluated the clinical results and courses in patients with malignant glioma under 15 years. Among 183 patients with brain tumors treated by our group using BSH-based intra-operative BNCT, 23 patients were under 15 years. They included 4 patients under 3 years. There were 3 glioblastomas (GBM), 6 anaplastic astrocytomas(AAS), 7 primitive neuroectodermal tumors (PNET), 6 pontine gliomas and 1 anaplastic ependymoma. All GBM and PNET patients died due to CSF and/or CNS dissemination without local tumor regrowth. All pontine glioma patients died due to regrowth of the tumor. Four of 6 anaplastic astrocytoma and 1 anaplastic ependymoma patients alive without tumor recurrence. BNCT can be applied to malignant brain tumors in children, especially under 3 years instead of conventional radiation. Although it can achieve the local control in the primary site, it cannot prevent CSF dissemination in patients with glioblastoma.

  11. Clinical results of BNCT for malignant brain tumors in children

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Yoshinobu [Department of Neurosurgery, Kagawa National Children' s Hospital, Kagawa 765-8501 (Japan)], E-mail: ynakagawa0517@yahoo.co.jp; Kageji, Teruyoshi; Mizobuchi, Yoshifumi [Department of Neurosurgery, University of Tokushima, Tokushima 770-8503 (Japan); Kumada, Hiroaki [Department of Research Reactor, Japan Atomic Energy Research Institute, Ibaragi 319-1195 (Japan); Nakagawa, Yoshiaki [Department of Medical Informatics, Post Graduated School, Kyoto University, Kyoto (Japan)

    2009-07-15

    It is very difficult to treat the patients with malignant brain tumor in children, especially under 3 years, because the conventional irradiation cannot be applied due to the damage of normal brain tissue. However, boron neutron capture therapy (BNCT) has tumor selectivity such that it can make damage only in tumor cells. We evaluated the clinical results and courses in patients with malignant glioma under 15 years. Among 183 patients with brain tumors treated by our group using BSH-based intra-operative BNCT, 23 patients were under 15 years. They included 4 patients under 3 years. There were 3 glioblastomas (GBM), 6 anaplastic astrocytomas(AAS), 7 primitive neuroectodermal tumors (PNET), 6 pontine gliomas and 1 anaplastic ependymoma. All GBM and PNET patients died due to CSF and/or CNS dissemination without local tumor regrowth. All pontine glioma patients died due to regrowth of the tumor. Four of 6 anaplastic astrocytoma and 1 anaplastic ependymoma patients alive without tumor recurrence. BNCT can be applied to malignant brain tumors in children, especially under 3 years instead of conventional radiation. Although it can achieve the local control in the primary site, it cannot prevent CSF dissemination in patients with glioblastoma.

  12. Clinical impact of anatomo-functional evaluation of brain function during brain tumor surgery

    International Nuclear Information System (INIS)

    To attempt to improve surgical outcome of brain surgery, clinical significance of anatomo-functional evaluation of brain function during resection of brain tumors was assessed. Seventy four patients with glioma located near eloquent areas underwent surgery while awake. Intraoperative tractography-integrated functional neuronavigation and cortical/subcortical electrical stimulation were correlated with clinical symptoms during and after resection of tumors. Cortical functional areas were safely removed with negative electric stimulation and eloquent cortices could be removed in some circumstances. Subcortical functional mapping was difficult except for motor function. Studying cortical functional compensation allows more extensive removal of brain tumors located in the eloquent areas. (author)

  13. Automatic detection of brain tumors in MR images

    Czech Academy of Sciences Publication Activity Database

    Dvořák, P.; Kropatsch, W.G.; Bartušek, Karel

    Brno: University of technolgy, 2013, s. 577-580. ISBN 978-1-4799-0404-4. [International conference on telecommunications and signal processing /36./. Rome (IT), 02.07.2013-04.07.2013] R&D Projects: GA ČR GAP102/12/1104; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : brain symmetry * brain tumor * magnetic resonance * tumor detection Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  14. Proteomic and immunologic analyses of brain tumor exosomes

    OpenAIRE

    Graner, Michael W.; Alzate, Oscar; Dechkovskaia, Angelika M.; Keene, Jack D.; Sampson, John H; Mitchell, Duane A; Bigner, Darell D.

    2009-01-01

    Brain tumors are horrific diseases with almost universally fatal outcomes; new therapeutics are desperately needed and will come from improved understandings of glioma biology. Exosomes are endosomally derived 30–100 nm membranous vesicles released from many cell types into the extracellular milieu; surprisingly, exosomes are virtually unstudied in neuro-oncology. These microvesicles were used as vaccines in other tumor settings, but their immunological significance is unevaluated in brain tu...

  15. Glutamate Release by Primary Brain Tumors Induces Epileptic Activity

    OpenAIRE

    Buckingham, Susan C.; Campbell, Susan L.; Haas, Brian R.; Montana, Vedrana; Robel, Stefanie; Ogunrinu, Toyin; Sontheimer, Harald

    2011-01-01

    Epileptic seizures are a common and poorly understood co-morbidity for individuals with primary brain tumors. To investigate peritumoral seizure etiology, we implanted patient-derived glioma cells into scid mice. Within 14–18 days, glioma-bearing animals developed spontaneous, recurring abnormal EEG events consistent with epileptic activity that progressed over time. Acute brain slices from these animals showed significant glutamate release from the tumor mediated by the system xc − cystine/g...

  16. Specific features of epilepsy in children with brain tumors

    OpenAIRE

    G. V. Kalmykova; A. F. Neretina; Zh. Yu. Chefranova

    2015-01-01

    Objective: to study the specific features of epilepsy in children and adolescents with brain tumors and to define the optimal tactics of management and antiepileptic therapy after surgical treatment. Patients and methods. Sixty-one patients aged 5 months to 15 years were examined. All the patients were diagnosed as having a brain tumor found in the presence of symptomatic epilepsy. They were all followed up for 5 years postsurgery or during their lifetime (in case of death). Comprehensive exa...

  17. Brain Tumor Detection Based On Mathematical Analysis and Symmetry Information

    OpenAIRE

    Narkhede Sachin G.,; Prof. Vaishali Khairnar

    2014-01-01

    Image segmentation some of the challenging issues on brain magnetic resonance (MR) image tumor segmentation caused by the weak correlation between magnetic resonance imaging (MRI) intensity and anatomical meaning. With the objective of utilizing more meaningful information to improve brain tumor segmentation, an approach which employs bilateral symmetry information as an additional feature for segmentation is proposed. This is motivated by potential performance improvement in ...

  18. FDTD analysis of a noninvasive hyperthermia system for brain tumors

    Directory of Open Access Journals (Sweden)

    Yacoob Sulafa M

    2012-08-01

    Full Text Available Abstract Background Hyperthermia is considered one of the new therapeutic modalities for cancer treatment and is based on the difference in thermal sensitivity between healthy tissues and tumors. During hyperthermia treatment, the temperature of the tumor is raised to 40–45°C for a definite period resulting in the destruction of cancer cells. This paper investigates design, modeling and simulation of a new non-invasive hyperthermia applicator system capable of effectively heating deep seated as well as superficial brain tumors using inexpensive, simple, and easy to fabricate components without harming surrounding healthy brain tissues. Methods The proposed hyperthermia applicator system is composed of an air filled partial half ellipsoidal chamber, a patch antenna, and a head model with an embedded tumor at an arbitrary location. The irradiating antenna is placed at one of the foci of the hyperthermia chamber while the center of the brain tumor is placed at the other focus. The finite difference time domain (FDTD method is used to compute both the SAR patterns and the temperature distribution in three different head models due to two different patch antennas at a frequency of 915 MHz. Results The obtained results suggest that by using the proposed noninvasive hyperthermia system it is feasible to achieve sufficient and focused energy deposition and temperature rise to therapeutic values in deep seated as well as superficial brain tumors without harming surrounding healthy tissue. Conclusions The proposed noninvasive hyperthermia system proved suitable for raising the temperature in tumors embedded in the brain to therapeutic values by carefully selecting the systems components. The operator of the system only needs to place the center of the brain tumor at a pre-specified location and excite the antenna at a single frequency of 915 MHz. Our study may provide a basis for a clinical applicator prototype capable of heating brain tumors.

  19. In vitro growth environment produces lipidomic and electron transport chain abnormalities in mitochondria from non-tumorigenic astrocytes and brain tumours

    Directory of Open Access Journals (Sweden)

    Thomas N Seyfried

    2009-05-01

    Full Text Available The mitochondrial lipidome influences ETC (electron transport chain and cellular bioenergetic efficiency. Brain tumours are largely dependent on glycolysis for energy due to defects in mitochondria and oxidative phosphorylation. In the present study, we used shotgun lipidomics to compare the lipidome in highly purified mitochondria isolated from normal brain, from brain tumour tissue, from cultured tumour cells and from non-tumorigenic astrocytes. The tumours included the CT-2A astrocytoma and an EPEN (ependymoblastoma, both syngeneic with the C57BL/6J (B6 mouse strain. The mitochondrial lipidome in cultured CT-2A and EPEN tumour cells were compared with those in cultured astrocytes and in solid tumours grown in vivo. Major differences were found between normal tissue and tumour tissue and between in vivo and in vitro growth environments for the content or composition of ethanolamine glycerophospholipids, phosphatidylglycerol and cardiolipin. The mitochondrial lipid abnormalities in solid tumours and in cultured cells were associated with reductions in multiple ETC activities, especially Complex I. The in vitro growth environment produced lipid and ETC abnormalities in cultured non-tumorigenic astrocytes that were similar to those associated with tumorigenicity. It appears that the culture environment obscures the boundaries of the Crabtree and the Warburg effects. These results indicate that in vitro growth environments can produce abnormalities in mitochondrial lipids and ETC activities, thus contributing to a dependency on glycolysis for ATP production.

  20. Glutamate Mediated Astrocytic Filtering of Neuronal Activity

    OpenAIRE

    Wallach, Gilad; Lallouette, Jules; Herzog, Nitzan; De Pittà, Maurizio; Ben Jacob, Eshel; Berry, Hugues; Hanein, Yael

    2014-01-01

    Neuron-astrocyte communication is an important regulatory mechanism in various brain functions but its complexity and role are yet to be fully understood. In particular, the temporal pattern of astrocyte response to neuronal firing has not been fully characterized. Here, we used neuron-astrocyte cultures on multi-electrode arrays coupled to Ca2+ imaging and explored the range of neuronal stimulation frequencies while keeping constant the amount of stimulation. Our results reveal that astrocyt...

  1. Assessment of brain retraction injury from tumor operation with 99Tcm-ECD brain SPECT imaging

    International Nuclear Information System (INIS)

    Objective: To evaluate the rCBF of brain retraction injury by 99Tcm-ECD SPECT imaging. Methods: The 99Tcm-ECD SPECT brain imaging was performed in 21 patients with brain tumor before and after operation. To compare the rCBF of peripheral tumor region with that of retraction injury region by semi-quantitative analysis. The rCBF levels of the central and peripheral areas of brain retraction injury were also studied. Results: Both the peripheral tumor region before operation and retraction region after operation were ischemic, but the difference between them was significant (P99Tcm-ECD SPECT brain imaging is a useful technique in detecting retraction injury come from brain tumor operation

  2. Brain tumor imaging of rat fresh tissue using terahertz spectroscopy

    Science.gov (United States)

    Yamaguchi, Sayuri; Fukushi, Yasuko; Kubota, Oichi; Itsuji, Takeaki; Ouchi, Toshihiko; Yamamoto, Seiji

    2016-07-01

    Tumor imaging by terahertz spectroscopy of fresh tissue without dye is demonstrated using samples from a rat glioma model. The complex refractive index spectrum obtained by a reflection terahertz time-domain spectroscopy system can discriminate between normal and tumor tissues. Both the refractive index and absorption coefficient of tumor tissues are higher than those of normal tissues and can be attributed to the higher cell density and water content of the tumor region. The results of this study indicate that terahertz technology is useful for detecting brain tumor tissue.

  3. Brain abscesses in diffusion-weighted imaging (DWI) - comparison to cystic brain tumors

    International Nuclear Information System (INIS)

    The clinical usefulness of diffusion-weighted imaging (DWI) was evaluated in patients with brain abscesses in comparison to patients with cystic brain tumors. Five patients with surgically confirmed brain abscesses underwent beside a brain MRI examination with contrast media application diffusion weighted imaging. Apparent diffusion coefficients (rADC) in three orthogonal diffusion gradient were calculated. The same protocol was used to examine 5 patients with cystic brain tumors. Showing an rADC of 0.33 x 10-3/mm2/s abscesses have a highly restricted diffusion in comparison to cystic brain tumors with an rADC of 1,67 x 10-3/mm2/s. Diffusion weighted imaging is a usefull diagnostic tool in the work up of brain abscesses. (orig.)

  4. Evaluation of intraoperative brain shift using an ultrasound-linked navigation system for brain tumor surgery

    International Nuclear Information System (INIS)

    Image-guided neurosurgery using navigation systems is an essential tool to increase accuracy in brain tumor surgery. However, brain shift during surgery has remained problematic. The present study evaluated the utility of a new ultrasound (US)-linked navigation system for brain tumor surgery in 64 patients with intracranial tumors. The navigation system consisted of a StealthStationTM navigation system, a SonoNavTM system, and a standard US scanner. This system determines the orientation of the US images and reformats the images from preoperative computed tomography (CT) or magnetic resonance (MR) imaging to match the US images. The system was used intraoperatively to measure brain shift several times, using the results to guide tumor resection. US-linked navigation provided information regarding brain shift, and extent of tumor resection during surgery. Evaluation of brain shift was easily achieved in all patients, without using intraoperative CT or MR imaging. Accurate information regarding the true anatomical configuration of the patient could be obtained in all phases of the operation. Magnitude of brain shift increased progressively from pre- to post-resection and depended on the type of cranial structure. Integration of the US scanner with the navigation system allowed comparisons between the intraoperative US and preoperative images, thus improving interpretation of US images. The system also improved the rate of tumor resection by facilitating the detection of remnant tumor tissue. This US-linked navigation system provides information on brain shift, and improves the accuracy and utility of image-guided surgery. (author)

  5. The Multimodal Brain Tumor Image Segmentation Benchmark (BRATS)

    DEFF Research Database (Denmark)

    Menze, Bjoern H.; Jakab, Andras; Bauer, Stefan;

    2015-01-01

    In this paper we report the set-up and results of the Multimodal Brain Tumor Image Segmentation Benchmark (BRATS) organized in conjunction with the MICCAI 2012 and 2013 conferences. Twenty state-of-the-art tumor segmentation algorithms were applied to a set of 65 multi-contrast MR scans of low- a...

  6. Wavelet Based Image Fusion for Detection of Brain Tumor

    Directory of Open Access Journals (Sweden)

    CYN Dwith

    2013-01-01

    Full Text Available Brain tumor, is one of the major causes for the increase in mortality among children and adults. Detecting the regions of brain is the major challenge in tumor detection. In the field of medical image processing, multi sensor images are widely being used as potential sources to detect brain tumor. In this paper, a wavelet based image fusion algorithm is applied on the Magnetic Resonance (MR images and Computed Tomography (CT images which are used as primary sources to extract the redundant and complementary information in order to enhance the tumor detection in the resultant fused image. The main features taken into account for detection of brain tumor are location of tumor and size of the tumor, which is further optimized through fusion of images using various wavelet transforms parameters. We discuss and enforce the principle of evaluating and comparing the performance of the algorithm applied to the images with respect to various wavelets type used for the wavelet analysis. The performance efficiency of the algorithm is evaluated on the basis of PSNR values. The obtained results are compared on the basis of PSNR with gradient vector field and big bang optimization. The algorithms are analyzed in terms of performance with respect to accuracy in estimation of tumor region and computational efficiency of the algorithms.

  7. Crossing the barrier: treatment of brain tumors using nanochain particles.

    Science.gov (United States)

    Karathanasis, Efstathios; Ghaghada, Ketan B

    2016-09-01

    Despite advancements in surgery and radiotherapy, the aggressive forms of brain tumors, such as gliomas, are still uniformly lethal with current therapies offering only palliation complicated by significant toxicities. Gliomas are characteristically diffuse with infiltrating edges, resistant to drugs and nearly inaccessible to systemic therapies due to the brain-tumor barrier. Currently, aggressive efforts are underway to further understand brain-tumor's microenvironment and identify brain tumor cell-specific regulators amenable to pharmacologic interventions. While new potent agents are continuously becoming available, efficient drug delivery to brain tumors remains a limiting factor. To tackle the drug delivery issues, a multicomponent chain-like nanoparticle has been developed. These nanochains are comprised of iron oxide nanospheres and a drug-loaded liposome chemically linked into a 100-nm linear, chain-like assembly with high precision. The nanochain possesses a unique ability to scavenge the tumor endothelium. By utilizing effective vascular targeting, the nanochains achieve rapid deposition on the vascular bed of glioma sites establishing well-distributed drug reservoirs on the endothelium of brain tumors. After reaching the target sites, an on-command, external low-power radiofrequency field can remotely trigger rapid drug release, due to mechanical disruption of the liposome, facilitating widespread and effective drug delivery into regions harboring brain tumor cells. Integration of the nanochain delivery system with the appropriate combination of complementary drugs has the potential to unfold the field and allow significant expansion of therapies for the disease where success is currently very limited. WIREs Nanomed Nanobiotechnol 2016, 8:678-695. doi: 10.1002/wnan.1387 For further resources related to this article, please visit the WIREs website. PMID:26749497

  8. Involvement of tumor acidification in brain cancer pathophysiology

    OpenAIRE

    AvinashHonasoge

    2013-01-01

    Gliomas, primary brain cancers, are characterized by remarkable invasiveness and fast growth. While they share many qualities with other solid tumors, gliomas have developed special mechanisms to convert the cramped brain space and other limitations afforded by the privileged central nervous system into pathophysiological advantages. In this review we discuss gliomas and other primary brain cancers in the context of acid-base regulation and interstitial acidification; namely, how the altered ...

  9. Galunisertib inhibits glioma vasculogenic mimicry formation induced by astrocytes.

    Science.gov (United States)

    Zhang, Chao; Chen, Wenliang; Zhang, Xin; Huang, Bin; Chen, Aanjing; He, Ying; Wang, Jian; Li, Xingang

    2016-01-01

    Gliomas are among the most lethal primary brain tumors found in humans. In high-grade gliomas, vasculogenic mimicry is often detected and has been correlated with prognosis, thus suggesting its potential as a therapeutic target. Vasculogenic mimicry mainly forms vascular-like channels independent of endothelial cells; however, little is known about the relationship between astrocytes and vasculogenic mimicry. In our study, we demonstrated that the presence of astrocytes promoted vasculogenic mimicry. With suspension microarray technology and in vitro tube formation assays, we identified that astrocytes relied on TGF-β1 to enhance vasculogenic mimicry. We also found that vasculogenic mimicry was inhibited by galunisertib, a promising TGF-β1 inhibitor currently being studied in an ongoing trial in glioma patients. The inhibition was partially attributed to a decrease in autophagy after galunisertib treatment. Moreover, we observed a decrease in VE-cadherin and smooth muscle actin-α expression, as well as down-regulation of Akt and Flk phosphorylation in galunisertib-treated glioma cells. By comparing tumor weight and volume in a xenograft model, we acquired promising results to support our theory. This study expands our understanding of the role of astrocytes in gliomas and demonstrates that galunisertib inhibits glioma vasculogenic mimicry induced by astrocytes. PMID:26976322

  10. Congenital Brain Tumors, a Series of Seven Patients

    Directory of Open Access Journals (Sweden)

    Farideh Nejat

    2007-05-01

    Full Text Available Objective: Congenital brain tumors are very rare. We review these tumors in patients younger than 2 months diagnosed in our Department. Material & Methods: Seven congenital brain tumors were diagnosed during five years. Clinical and radiological findings and prognosis are analyzed. Findings: The study included 5 female and two male infants. Two cases were diagnosed antenatally by means of ultrasonography. All patients presented with intracranial hypertension. The tumor was non-homogenous with cystic and solid components in all neuroimaging, except for the case with choroid plexus papilloma. Hydrocephalus was evident in all of them. Most findings were infra-tentorial lesions. There were three teratomas, one primitive neuro-ectodermal tumor, one ependymoblastoma and one choroid plexus papilloma. Six patients were operated on, with one intra-operative death. Two passed away postoperatively with aspiration pneumonia. One patient died due to complications of chemotherapy and another one due to tumor recurrence one year after surgery. Only the patient with choroid plexus papilloma is alive after 2 years. Conclusion: Today, the availability of noninvasive imaging procedures such as computerized tomography scan and magnetic resonance imaging has improved the diagnosis of congenital brain tumors. Inspite of development in prenatal diagnosis, appropriate pre and post operative management, the mortality associated with these tumors still remains high. The final prognosis in these patients is still discouraging despite early surgery and operative and anesthetic improvements. Choroid plexus papilloma accompanies the best prognosis, whereas teratoma and primitive neuroectodermal tumors have the worst prognosis.

  11. Evolution of Brain Tumor and Stability of Geometric Invariants

    Directory of Open Access Journals (Sweden)

    K. Tawbe

    2008-01-01

    Full Text Available This paper presents a method to reconstruct and to calculate geometric invariants on brain tumors. The geometric invariants considered in the paper are the volume, the area, the discrete Gauss curvature, and the discrete mean curvature. The volume of a tumor is an important aspect that helps doctors to make a medical diagnosis. And as doctors seek a stable calculation, we propose to prove the stability of some invariants. Finally, we study the evolution of brain tumor as a function of time in two or three years depending on patients with MR images every three or six months.

  12. Growth enhancement effect of BzATP on primary cultured astrocytes from rat brain

    Institute of Scientific and Technical Information of China (English)

    Hua-Zheng LIANG; Ying LIU; Zhu-Rong YE

    2006-01-01

    Objective To explore whether BzATP could promote the growth of primary cultured astrocytes (AS) of rat and its possible mechanism, and whether TGF-β1 was involved in the event. Methods The primary cultured AS were derived from new born Sprague-Dawley rats.Glial fibrillary acidic protein (GFAP) immunofluorescent stain was used to check the purity of cultured AS. Morphometry was used to detect the changes of AS. The proliferation index of AS was detected by BrdU incorporation assay. Western blot was used to detect the changes of GFAP under different conditions. Changes of TGF-β1 gene transcription were detected by RT-PCR. ELISA was utilized to detect the variation of TGF-β1 protein in the supernate. Results The purity of primary cultured AS reached to 99%. BzATP promoted the hypertrophy of AS including the elongation of AS processes and the enlargement of cell bodies, BzATP also promoted the expression of GFAP in existence of Ca2+, but had no effect on cell proliferation. BzATP increased the transcription of TGF-β1 mRNA and the release of TGF-β1 protein in existence of Ca2+. TGF-β1 neutralizing antibody partially inhibited the expression of GFAP induced by BzATP, but had no effect on AS proliferation and cell morphology. Conclusion BzATP enhanced the hypertrophy of primary cultured AS, increased the expression of GFAP partially through TGF-β1. Mechanisms of the enhancement of AS growth induced by BzATP other than TGF-51 pathway remains to be elucidated.

  13. Subacute brain atrophy induced by radiation therapy to the malignant brain tumors

    International Nuclear Information System (INIS)

    In order to analyze brain atrophy after radiation therapy to the brain tumors, we calculated a CSF-cranial volume ratio on CT scan as an index of brain atrophy, and estimated dementia-score by Hasegawa's method in 91 post-irradiated patients with malignant brain tumors. Radiation-induced brain atrophy was observed in 51 out of 91 patients (56 %) and dementia in 23 out of 47 patients (49 %). These two conditions were closely related, and observed significantly more often in aged and whole-brain-irradiated patients. As radiation-induced brain atrophy accompanied by dementia appeared 2 - 3 months after the completion of radiation therapy, it should be regarded as a subacute brain injury caused by radiation therapy. (author)

  14. Computed tomography of virally induced monkey brain tumors

    International Nuclear Information System (INIS)

    Thirty-five (35) Japanese monkeys (Macaca fuscata) were inoculated intracerebrally with chickembryo fibroblasts which were producing the Schmidt-Ruppin strain of the Rous sarcoma virus. These were then studied by means of computed tomography (CT) to detect brain tumors. Tumors were induced in 54.3% (19/35), with an average latency of 32.6 (15 - 43) days before a CT image appeared. The brains were sectioned into 5-mm slices, coplanar with the CT images. Various CT features, such as necrosis, hemorrhage, and peritumoral edema, correlated with the pathological findings. Contrast-enhanced CT detected tumors greater than 4-6 mm in diameter, and it was accurate within 2 mm in determining. Following brain tumors by CT in 6 monkeys revealed changes in the tumor size. One monkey was treated by differential hypothermia following craniectomy; the therapeutic effect and the tumor size, as subsequently evaluated for six months, revealed tumor regression during the initial 5 weeks, followed by stabilization and late (6 months) progression. The large brain size, 90-110 grams in adults, and the availability of these monkeys make them an excellent model system for neurological, neurosurgical, CT, and multimodality therapeutic experimentation. (author)

  15. Stereotaxic interstitial implantation for the treatment of malignant brain tumors

    International Nuclear Information System (INIS)

    The Brain Tumor Study Group (BTSG) demonstrated that patients with malignant gliomas who were treated with radiation therapy to a dose of 50 Gray (Gy) or more to the whole brain survived significantly longer than patients treated with surgery alone. A dose-response analysis of the BTSG data for 621 patients, 90% of whom had glioblastoma multiforme, showed a stepwise improvement in survival in patient groups receiving 50, 55, or 60 Gy. The median survival times were 28, 36, and 42 weeks, respectively (difference between 50 and 60 Gy significant at rho = .004). However, all tumors recurred and all patients died of their disease. If higher doses of radiation therapy could be delivered, improved local tumor control might be achieved. However, the delivery of doses of external irradiation in excess of 60 Gy is accompanied by radiation-induced brain necrosis. Experimental therapeutic strategies in the treatment of malignant brain tumors have involved the use of systemic chemotherapy. However, because of the localized nature of malignant glial tumors, it would seem logical to consider additional local treatment modalities. As radiation therapy has proven to be the most effective adjunct to surgery in the treatment of malignant brain tumors, there has been considerable recent interest in interstitial radiation therapy. Using interstitial radiation sources, high-dose radiation therapy can be delivered to the primary tumor with relative sparing of surrounding normal tissues. Interstitial implantation could be employed alone or to augment the dose delivered by external beam irradiation for the treatment of primary brain tumors, and would allow radical re-irradiation of recurrent malignant gliomas

  16. Detection and photoaffinity labeling of the Ca2+-activated K+ channel-associated apamin receptor in cultured astrocytes from rat brain.

    Science.gov (United States)

    Seagar, M J; Deprez, P; Martin-Moutot, N; Couraud, F

    1987-05-19

    Apamin, an 18-amino acid bee venom peptide, is a specific blocker of a class of Ca2+ activated K+ channels. Mono 125I-iodoapamin was used to detect the K+ channel-associated receptor site in cultured astrocytes from rat brain. Specific high-affinity binding to intact glial cells with a Kd of about 90 pM at 1 degree C and pH 7.5 was demonstrated by equilibrium and kinetic methods. The average receptor capacity was 3 fmol/mg cell protein which is 2 to 3-fold lower than in primary cultured neurons. Binding was stimulated by K+ ions, but to a lesser extent than with neuronal receptors. Photoaffinity labeling of receptor/ion channel components using an arylazide derivative of 125I-monoiodoapamin revealed the presence of the 86- and 33-kDa polypeptides, previously detected in neurones. However a 59-kDa peptide which is present in synaptic membrane preparations from adult rat brain, but not in cultured neurons, was also clearly labeled in intact astrocytes. This indicates that the 59-kDa polypeptide is not a proteolytic fragment of the 86-kDa chain but an associated subunit which is only accessible to photolabeling in certain apamin receptor preparations. Apamin-sensitive Ca2+-activated K+ channels in astrocytes may be one of the pathways by which glial cells redistribute K+ in the central nervous system (CNS). PMID:2440516

  17. Differences in distribution and regulation of astrocytic aquaporin-4 in human and rat hydrocephalic brain

    DEFF Research Database (Denmark)

    Skjolding, Anders Daehli; Holst, Anders Vedel; Broholm, Helle;

    2013-01-01

    human hydrocephalic cortex relative to controls was quantified by western blotting (n=28). A second biopsy (n=13) was processed for immunohistochemistry (GFAP, CD68, CD34 and aquaporin-4) and double immunofluorescence (aquaporin-4+GFAP and aquaporin-4+CD34). Brain tissue from human controls and kaolin...

  18. Research of the multimodal brain-tumor segmentation algorithm

    Science.gov (United States)

    Lu, Yisu; Chen, Wufan

    2015-12-01

    It is well-known that the number of clusters is one of the most important parameters for automatic segmentation. However, it is difficult to define owing to the high diversity in appearance of tumor tissue among different patients and the ambiguous boundaries of lesions. In this study, a nonparametric mixture of Dirichlet process (MDP) model is applied to segment the tumor images, and the MDP segmentation can be performed without the initialization of the number of clusters. A new nonparametric segmentation algorithm combined with anisotropic diffusion and a Markov random field (MRF) smooth constraint is proposed in this study. Besides the segmentation of single modal brain tumor images, we developed the algorithm to segment multimodal brain tumor images by the magnetic resonance (MR) multimodal features and obtain the active tumor and edema in the same time. The proposed algorithm is evaluated and compared with other approaches. The accuracy and computation time of our algorithm demonstrates very impressive performance.

  19. Preliminary results of fractionated stereotactic radiotherapy for benign brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Byung Ock [College of Medicine, Catholic Univ., Seoul (Korea, Republic of); Kang, Ki Mun [Cellege of Medicine, Gyeongsang National Univ., Jinju, (Korea, Republic of)

    2003-03-01

    To evaluate the role of fractionated stereotactic radiotherapy (FSRT) in the management of benign brain tumors, we reviewed the clinical, and radiographic responses of patients treated. Between March 1996 and March 2002, 36 patients with benign brain tumors were treated by FSRT. The pathological diagnoses consisted of pituitary adenomas (12 patients), craniopharyngiomas (5 patients), meningiomas (10 patients), and acoustic neurinomas (9 patients). Radiotherapy doses of 25 to 35 Gy (3-6 Gy/fraction, 5-10 fractions) were prescribed to the 85-90% isodose line, depending upon the location, size and volume of the tumors. The median clinical and radiographical followup periods were 31 [range, 2-74) and 21 (range, 4-56) months, respectively. In the 35 patients that could be evaluated for their clinical response, 13 (37.1%) were considered improved, 16 (45.7%) stable and 6 (17.2%) worse. Of the 33 patients who had radiographic studies, tumor shrinkage was noted in 17 (51.5%), tumor stabilization in 13 (39.4%), and tumor progression in 3 (9,1%). Of the 17 tumor shrinkage patients, 7 [21.2%) showed a complete response, Acute radiation-induced complications occurred in 11 (30.6%) patients. FSRT is considered a safe and effective treatment method for benign brain tumors but large numbers of patients, with relatively long follow-up periods are needed to assess the exact role or effect of FSRT.

  20. High-neurovirulence GDVII virus induces apoptosis in murine astrocytes through tumor necrosis factor (TNF)-receptor and TNF-related apoptosis-inducing ligand

    International Nuclear Information System (INIS)

    We carried out a study to determine if the high-neurovirulence GDVII strain of Theiler's murine encephalomyelitis virus (TMEV) and the demyelinating, low-neurovirulence BeAn strain induced apoptosis in murine astrocytes. Astrocytes, the major glial cell population of the central nervous system, were semipermissive for GDVII virus replication. Programmed cell death, demonstrated by apoptosis-specific caspase-3 protease activity, was maximal 8 h after GDVII infection at an m.o.i. of 1. Purified TMEV capsid proteins VP1, VP2, and VP3 did not induce apoptosis but antibodies to VP1 and VP2 inhibited it. Antibody inhibition of caspase-3 activity as well as flow cytometry experiments implicated TNF-related apoptosis-inducing ligand (TRAIL) and TNF-α-receptor (TNF-R) in apoptosis signaling. Converselly, TNF-α and the TRAIL-receptor were not upregulated. Furthermore, the number of functional TNF-α receptors, but not their affinity, was increased in apoptotic GDVII virus-infected astrocytes, as confirmed in binding experiments with 125I-labeled recombinant murine TNF-α. In vivo studies showed that most of the cells loaded with the virus when injected in the brains of SJL mice were neurons but very few showed TUNEL costaining. Conversely, many of the apoptotic cells found were also positive for GFAP staining

  1. Activation of P2X(7) receptors stimulates the expression of P2Y(2) receptor mRNA in astrocytes cultured from rat brain.

    Science.gov (United States)

    D'Alimonte, I; Ciccarelli, R; Di Iorio, P; Nargi, E; Buccella, S; Giuliani, P; Rathbone, M P; Jiang, S; Caciagli, F; Ballerini, P

    2007-01-01

    Under pathological conditions brain cells release ATP at concentrations reported to activate P2X(7) ionotropic receptor subtypes expressed in both neuronal and glial cells. In the present study we report that the most potent P2X(7) receptor agonist BzATP stimulates the expression of the metabotropic ATP receptor P2Y(2) in cultured rat brain astrocytes. In other cell types several kinds of stimulation, including stress or injury, induce P2Y(2) expression that, in turn, is involved in different cell reactions. Similarly, it has recently been found that in astrocytes and astrocytoma cells P2Y(2) sites can trigger neuroprotective pathways through the activation of several mechanisms, including the induction of genes for antiapoptotic factors, neurotrophins, growth factors and neuropeptides. Here we present evidence that P2Y(2) mRNA expression in cultured astrocytes peaks 6 h after BzATP exposure and returns to basal levels after 24 h. This effect was mimicked by high ATP concentrations (1 mM) and was abolished by P2X(7)-antagonists oATP and BBG. The BzATP-evoked P2Y(2) receptor up-regulation in cultured astrocytes was coupled to an increased UTP-mediated intracellular calcium response. This effect was inhibited by oATP and BBG and by P2Y(2)siRNA, thus supporting evidence of increased P2Y(2) activity. To further investigate the mechanisms by which P2X(7) receptors mediated the P2Y(2) mRNA up-regulation, the cells were pre-treated with the chelating agent EGTA, or with inhibitors of mitogen-activated kinase (MAPK) (PD98059) or protein kinase C, (GF109203X). Each inhibitor significantly reduced the extent to which BzATP induced P2Y(2) mRNA. Both BzATP and ATP (1 mM) increased ERK1/2 activation. P2X(7)-induced ERK1/2 phosphorylation was unaffected by pre-treatment of astrocytes with EGTA whereas it was inhibited by GF109203X. Phorbol-12-myristate-13-acetate (PMA), an activator of PKCs, rapidly increased ERK1/2 activation. We conclude that activation of P2X(7) receptors in

  2. Performance Analysis of Unsupervised Clustering Methods for Brain Tumor Segmentation

    Directory of Open Access Journals (Sweden)

    Tushar H Jaware

    2013-10-01

    Full Text Available Medical image processing is the most challenging and emerging field of neuroscience. The ultimate goal of medical image analysis in brain MRI is to extract important clinical features that would improve methods of diagnosis & treatment of disease. This paper focuses on methods to detect & extract brain tumour from brain MR images. MATLAB is used to design, software tool for locating brain tumor, based on unsupervised clustering methods. K-Means clustering algorithm is implemented & tested on data base of 30 images. Performance evolution of unsupervised clusteringmethods is presented.

  3. CT-guided laser probe for ablation of brain tumors

    Directory of Open Access Journals (Sweden)

    Abdolhadi Daneshi

    2010-01-01

    Full Text Available   Abstract  In this study, 22 patients (15-75 years old were selected and transferred to CT scan for tumor ablation. For ablations, after prep and drep under the local anesthesia and mild sedation in proper position, small incision made and special needle inserted and guided by proper direction to the core of the tumor. Then, laser probe inserted through the needle and laser energy delivered. Although we have not a good prognosis in metastatic tumors but post-operative follow up and brain CT scan established the effect of laser on resection and evaporation and diminution of mass effect in tumor lesions.

  4. Ganglion cells in circumscribed astrocytic tumors: possible implication in classification and prognosis

    Directory of Open Access Journals (Sweden)

    Veronica Goulart Moreira

    2013-06-01

    Full Text Available INTRODUCTION: Glial and neuroglial cell neoplasms comprise pilocytic astrocytoma (PA, pleomorphic xanthoastrocytoma (PXA and ganglioglioma (GG, which share various similarities, though PA has better prognosis. As ganglion cells (GC may be scarce in GG and these gangliogliomas may recur or progress to grade III, an accurate diagnosis is essential. OBJECTIVES: The aim was to identify GC and eosinophilic granular bodies (EGB in PA and PXA, to evaluate its effect on patient’s outcome and compare them with GG. METHODS: A retrospective analysis of radiological, morphological and follow-up aspects (disease free-survival, recurrence and death of 30 cases (14 PA, 8 PXA, 8 GG. Hematoxylin and eosin (HE stained sections were reviewed to identify the presence of neoplastic GC and EGB. They were immunostained for synaptophysin (SYN and neurofilament (NF. Glial fibrillary acidic protein (GFAP immunostaining was performed in selected cases. RESULTS: Six PA were reclassified as GG due to the presence of GC by HE or immunohistochemistry. Some EGB resembling degenerate GC were also immunostained for SYN/NF and most of them were negative for GFAP. The mean disease-free survival was 62.16 months. Four tumors recurred and one patient died. All PXA had GC, suggesting that they were variants of GG, 4 of which recurred and one patient died. Mean disease-free survival was 69 months. The radiological aspect was predominantly cystic. CONCLUSION: We propose that PA and PXA with GC or with EGB immunopositive for neuronal markers could be variants of GG, and some EGB may represent degenerate GC. However, the presence of GC does not seem to modify the biological behavior of these neoplasms.

  5. Malignant primary germ-cell tumor of the brain

    International Nuclear Information System (INIS)

    The unusual case of a 15 year old boy with three discrete paraventricular germ-cell tumors is reported.FThe first tumor was located just lateral to the left thalamus and included a massive cystic part around it, the second tumor in the paraventricular region above the head of the left caudate nucleus and the third tumor in the medial part of the left parietal lobe.FTotal removal of all tumors was successfully accomplished in stages at four separate operations, namely, the first tumor was removed through the left transsylvian approach, the second tumor via left superior frontal gyrus and the third tumor via left superior frontal gyrus and left superior parietal lobule.FHistological examination revealed that the first tumor was teratoma, the second was choriocarcinoma and the third was germinoma.FPrimary germ-cell tumors of the brain can be divided into 5 groups: 1) germinoma; 2) embryonal carcinoma; 3) choriocarcinoma; 4) yolk-sac tumor; or 5) teratoma.FIn this case, a combination of three different histological patterns was seen. If malignant germ-cell tumor is supected on CT, aggressive extirpation should be done, not only to determine the exact diagnosis, but also to provide the basis for subsequent adjunctive therapy. (author)

  6. Changes in astrocyte morphology and extracellular space volume fraction in brain slices after ischemia

    Czech Academy of Sciences Publication Activity Database

    Anděrová, Miroslava; Hock, Miroslav; Antonova, Tatiana; Chvátal, Alexandr; Syková, Eva

    Lisabon, 2004. s. 495. [Forum of European Neuroscience /4./. 10.07.2004-14.07.2004, Lisabon] R&D Projects: GA ČR GA305/02/1528; GA ČR GA305/03/1172; GA ČR GA305/04/1293; GA MŠk LN00A065 Keywords : extracellular space * brain ischemia Subject RIV: FH - Neurology

  7. Multidrug resistance (MDR) in brain tumors; its clinical importance

    International Nuclear Information System (INIS)

    MDR is one of the important factors affecting chemotherapy in high grade brain malignancies. Especially it affects commonly used agents such as vincristine, VP16, VM26, and cisplatin. MDR1 gene encoded P-glycoprotein (Pgp) prevents intratumoral retention of such drugs by expelling them at the plasma membrance of brain tumor cells. Therefore, the objective of this study was to evaluate MDR in various brain tumors including metastatic tumors including metastatic tumors by dual isotope SPECT, Northern blotting or immunohistochemical staining (IHCS) using JSB-1 monoclonal antibody against MDR1 gene encoded Pgp. Twenty one patients with various brain tumors of primary, secondary, and recurrent tumors were included from 2 institutions. Whenever possible, surgical specimen from these patients were obtained to study MDR. SPET was performed with a tripple head system (Trionix, Twinsburg, Ohio or MultiSPECT 3, Siemens). Three millicuries of 201Tl chloride and 20 mCi of 99mTc-sestamibi were adminstered and SPET was performed in about 15 min. Nineteen percent of patients had MIBI (-) and Tl (+) suggesting MDR (+). MIBI tumor uptake was higher in recurrence (6.67 +/- 1.3) than the stable original tumors (3.12 +/-0.77) (For 201Tl, 3.65 +/-2.2 Vs 1.5 +/-0.41). Three recurrent gliomas biopsied showed positive blotting and these patients failed several courses of chemotherapy. Six patients with various tumors such as oligodendroglioma, meningioma, recurrent G-M (2), and astrocytoma (2) were studied by IHCS, Weakly positive MDR was seen in one recurrent G-M and an astrocytoma case. Positive MDR was seen in the other recurrent G-M and a meningioma. In conclusion, MDR in brain tumors is detected successfully by dual isotope SPECT studies in a limited number of patients. MDR in benign brain tumors has no clinical significance since they are cured by surgical removal. However, we believe its presence in metastatic and high grade especially recurrent tumors is an essential information

  8. Multidrug resistance (MDR) in brain tumors; its clinical importance

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. Z. [Thomas Jefferson Univ., Philadelphia (United States); Park, C. H.; Kim, S. M.; Cho, K. K.; Bai, M. S.; Yoon, S. N.; Cho, C. W.; Jin, Y. M.; Kim, Y. S. [College of Medicine, Ajou Univ., Suwon (Korea, Republic of)

    1997-07-01

    MDR is one of the important factors affecting chemotherapy in high grade brain malignancies. Especially it affects commonly used agents such as vincristine, VP16, VM26, and cisplatin. MDR1 gene encoded P-glycoprotein (Pgp) prevents intratumoral retention of such drugs by expelling them at the plasma membrance of brain tumor cells. Therefore, the objective of this study was to evaluate MDR in various brain tumors including metastatic tumors including metastatic tumors by dual isotope SPECT, Northern blotting or immunohistochemical staining (IHCS) using JSB-1 monoclonal antibody against MDR1 gene encoded Pgp. Twenty one patients with various brain tumors of primary, secondary, and recurrent tumors were included from 2 institutions. Whenever possible, surgical specimen from these patients were obtained to study MDR. SPET was performed with a tripple head system (Trionix, Twinsburg, Ohio or MultiSPECT 3, Siemens). Three millicuries of {sup 201}Tl chloride and 20 mCi of {sup 99m}Tc-sestamibi were adminstered and SPET was performed in about 15 min. Nineteen percent of patients had MIBI (-) and Tl (+) suggesting MDR (+). MIBI tumor uptake was higher in recurrence (6.67 +/- 1.3) than the stable original tumors (3.12 +/-0.77) (For {sup 201}Tl, 3.65 +/-2.2 Vs 1.5 +/-0.41). Three recurrent gliomas biopsied showed positive blotting and these patients failed several courses of chemotherapy. Six patients with various tumors such as oligodendroglioma, meningioma, recurrent G-M (2), and astrocytoma (2) were studied by IHCS, Weakly positive MDR was seen in one recurrent G-M and an astrocytoma case. Positive MDR was seen in the other recurrent G-M and a meningioma. In conclusion, MDR in brain tumors is detected successfully by dual isotope SPECT studies in a limited number of patients. MDR in benign brain tumors has no clinical significance since they are cured by surgical removal. However, we believe its presence in metastatic and high grade especially recurrent tumors is an

  9. NF-kappaB-driven STAT2 and CCL2 expression in astrocytes in response to brain injury

    DEFF Research Database (Denmark)

    Khorooshi, Reza; Babcock, Alicia A; Owens, Trevor

    2008-01-01

    induces glial response. Astrocytes are the major glial population in the CNS. We examined expression of STATs and the chemokine CCL2 and their relationship to astroglial NF-kappaB signaling in the CNS following axonal transection. Double labeling with Mac-1/CD11b and glial fibrillary acidic protein...... revealed that STAT2 up-regulation and phosphorylation colocalized exclusively to astrocytes, suggesting the involvement of STAT2 activating signals selectively in astroglial response to injury. STAT1 was also up-regulated and phosphorylated but not exclusively in astrocytes. Both STAT2 up-regulation and...... phosphorylation were NF-kappaB -dependent since they did not occur in the lesion-reactive hippocampus of transgenic mice with specific inhibition of NF-kappaB activation in astrocytes. We further showed that lack of NF-kappaB signaling significantly reduced injury-induced CCL2 expression as well as leukocyte...

  10. Assessment of serum L-fucose in brain tumor cases

    Directory of Open Access Journals (Sweden)

    Manjula S

    2010-01-01

    Full Text Available Background: Glycosylation of altered tumor cell in relation to cellular heterogeneity in human intracranial tumors remains relatively unexposed. Serum protein-bound carbohydrate, L-Fucose is reported to be overexpressed during tumor progression by many investigators. Therefore, there is a need to determine the diagnostic, prognostic, functional significance of glycoprotein elevations in various cases of tumors. Objective: The objective of the present study was to evaluate the clinical utility of serum L-fucose in patients with brain tumor. Materials and Methods: Serum glyco-conjugate levels were estimated in 99 patients with brain tumors. Estimation of L-fucose was carried out colorimetrically by the method of Winzler using cysteine hydrochloride. Results: There was a significant increase in L-fucose level in most of the patients. In the posttreatment cases, the L-fucose levels were apparently low compared to preoperative values. Conclusion: Our results showed that the rise in serum L-fucose may be used as a general marker for brain tumors in addition to other markers.

  11. Development of a Novel Method for the Purification and Culture of Rodent Astrocytes

    OpenAIRE

    Foo, Lynette C.; Allen, Nicola J.; Bushong, Eric A.; Ventura, P. Britten; Chung, Won-Suk; Zhou, Lu; Cahoy, John D.; Daneman, Richard; Zong, Hui; Ellisman, Mark H.; Barres, Ben A.

    2011-01-01

    The inability to purify and culture astrocytes has long hindered studies of their function. Whereas astrocyte progenitor cells can be cultured from neonatal brain, culture of mature astrocytes from postnatal brain has not been possible. Here we report a new method to prospectively purify astrocytes by immunopanning. These astrocytes undergo apoptosis in culture, but vascular cells and HBEGF promote their survival in serum-free culture. We found that some developing astrocytes normally undergo...

  12. Neuronal modulation of calcium channel activity in cultured rat astrocytes.

    OpenAIRE

    Corvalan, V; Cole, R; de Vellis, J.; Hagiwara, S.

    1990-01-01

    The patch-clamp technique was used to study whether cocultivation of neurons and astrocytes modulates the expression of calcium channel activity in astrocytes. Whole-cell patch-clamp recordings from rat brain astrocytes cocultured with rat embryonic neurons revealed two types of voltage-dependent inward currents carried by Ca2+ and blocked by either Cd2+ or Co2+ that otherwise were not detected in purified astrocytes. This expression of calcium channel activity in astrocytes was neuron depend...

  13. Dysembryoplastic neuroepithelial tumor: A rare brain tumor not to be misdiagnosed

    OpenAIRE

    Sukheeja, Deepti; Mehta, Jayanti

    2016-01-01

    Dysembryoplastic neuroepithelial tumor (DNET) is a recently described, morphologically unique, and surgically curable low-grade brain tumor which is included in the latest WHO classification as neuronal and mixed neuronal-glial tumor. It is usually seen in children and young adults. The importance of this particular entity is that it is a surgically curable neuroepithelial neoplasm. When recognized, the need for adjuvant radiotherapy and chemotherapy is obviated. We hereby present a case repo...

  14. Photon spectrum and absorbed dose in brain tumor

    Energy Technology Data Exchange (ETDEWEB)

    Silva S, A. [General Electric Healthcare, Antonio Dovali Jaime 70, Torre A 3er. piso, Col. Santa Fe, 01210 Mexico D. F. (Mexico); Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria No. 694, 11500 Mexico D. F. (Mexico)

    2015-10-15

    Using Monte Carlo methods a BOMAB phantom inside a treatment hall with a brain tumor nearby the pituitary gland was treated with photons produced by a Varian 6 MV linac. The photon spectrum and the absorbed dose were calculated in the tumor, pituitary gland and the head. The treatment beam was collimated to illuminate only the tumor volume; however photons were noticed in the gland. Photon fluence reaching the tumor is 78.1 times larger than the fluence in the pituitary gland, on the other hand the absorbed dose in the tumor is 188 times larger than the dose in the gland because photons that reach the pituitary gland are scattered, by the head and the tumor, through Compton effect. (Author)

  15. Photon spectrum and absorbed dose in brain tumor

    International Nuclear Information System (INIS)

    Using Monte Carlo methods a BOMAB phantom inside a treatment hall with a brain tumor nearby the pituitary gland was treated with photons produced by a Varian 6 MV linac. The photon spectrum and the absorbed dose were calculated in the tumor, pituitary gland and the head. The treatment beam was collimated to illuminate only the tumor volume; however photons were noticed in the gland. Photon fluence reaching the tumor is 78.1 times larger than the fluence in the pituitary gland, on the other hand the absorbed dose in the tumor is 188 times larger than the dose in the gland because photons that reach the pituitary gland are scattered, by the head and the tumor, through Compton effect. (Author)

  16. Air pollution from traffic and risk for brain tumors

    DEFF Research Database (Denmark)

    Poulsen, Aslak Harbo; Sørensen, Mette; Andersen, Zorana J;

    2016-01-01

    residential nitrogen oxides (NO x ) concentrations since 1971 with a validated dispersion model. Categorical and linear odds ratios (OR) and confidence intervals (CI) were calculated with conditional logistic regression models. RESULTS: The highest risk estimates for any brain cancer were observed among......PURPOSE: Air pollution is an established lung carcinogen, and there is increasing evidence that air pollution also negatively affects the brain. We have previously reported an association between air pollution and risk of brain tumors in a cohort study based on only 95 cases. We set out to...... replicate that finding in a large nationwide case-control study. METHODS: We identified all 4,183 adult brain tumor cases in Denmark in the years 2000-2009 and 8,018 risk set sampled population controls matched on gender and year of birth. We extracted residential address histories and estimated mean...

  17. Gonadal status in male survivors following childhood brain tumors

    DEFF Research Database (Denmark)

    Schmiegelow, M; Lassen, S; Poulsen, H S; Schmiegelow, K; Hertz, H; Andersson, A M; Skakkebaek, N E; Müller, J

    2001-01-01

    The effect of radiotherapy (RT) and chemotherapy (CT) on gonadal function was assessed in males treated for a childhood brain tumor not directly involving the hypothalamus/pituitary (HP) axis in a population-based study with a long follow-up time. All males......The effect of radiotherapy (RT) and chemotherapy (CT) on gonadal function was assessed in males treated for a childhood brain tumor not directly involving the hypothalamus/pituitary (HP) axis in a population-based study with a long follow-up time. All males...

  18. Brain Tumor Detection Based On Mathematical Analysis and Symmetry Information

    Directory of Open Access Journals (Sweden)

    Narkhede Sachin G.,

    2014-02-01

    Full Text Available Image segmentation some of the challenging issues on brain magnetic resonance (MR image tumor segmentation caused by the weak correlation between magnetic resonance imaging (MRI intensity and anatomical meaning. With the objective of utilizing more meaningful information to improve brain tumor segmentation, an approach which employs bilateral symmetry information as an additional feature for segmentation is proposed. This is motivated by potential performance improvement in the general automatic brain tumor segmentation systems which are important for many medical and scientific applications. Brain Magnetic Resonance Imaging (MRI segmentation is a complex problem in the field of medical imaging despite various presented methods. MR image of human brain can be divided into several sub-regions especially soft tissues such as gray matter, white matter and cerebrospinal fluid. Although edge information is the main clue in image segmentation, it can’t get a better result in analysis the content of images without combining other information. Our goal is to detect the position and boundary of tumors automatically. Experiments were conducted on real pictures, and the results show that the algorithm is flexible and convenient.

  19. Clinical features of depressive disorders in patients with brain tumors

    Directory of Open Access Journals (Sweden)

    Ogorenko V.V.

    2014-03-01

    Full Text Available The aim of the study was to examine the structure of psychopathology and clinical features of depressive disorders in patients with brain oncopathology. Polymorphic mental disorders of various clinical content and severity in most cases not only are comorbid to oncological pathology of the brain, but most often are the first clinical signs of early tumors. The study was conducted using the following methods: clinical psychiatric, questionnaire Simptom Check List- 90 -Revised-SCL- 90 -R, Luscher test and mathematical processing methods. Sample included 175 patients with brain tumors with non-psychotic level of mental disorders. The peculiarities of mental disorders and psychopathological structure of nonpsychotic depressive disorders have been a clinical option of cancer debut in patients with brain tumors. We found that nonpsychotic depression is characterized by polymorphism and syndromal incompletion; this causes ambiguity of diagnoses interpretation on stages of diagnostic period. Features of depressive symptoms depending on the signs of malignancy / nonmalignancy of brain tumor were defined.

  20. Training stem cells for treatment of malignant brain tumors

    Institute of Scientific and Technical Information of China (English)

    Shengwen; Calvin; Li; Mustafa; H; Kabeer; Long; T; Vu; Vic; Keschrumrus; Hong; Zhen; Yin; Brent; A; Dethlefs; Jiang; F; Zhong; John; H; Weiss; William; G; Loudon

    2014-01-01

    The treatment of malignant brain tumors remains a challenge. Stem cell technology has been applied in the treatment of brain tumors largely because of the ability of some stem cells to infiltrate into regions within the brain where tumor cells migrate as shown in preclinical studies. However, not all of these efforts can translate in the effective treatment that improves the quality of life for pa-tients. Here, we perform a literature review to identify the problems in the field. Given the lack of efficacy of most stem cell-based agents used in the treatment of malignant brain tumors, we found that stem cell distribution(i.e., only a fraction of stem cells applied capable of targeting tumors) are among the limiting factors. We provide guidelines for potential improvements in stem cell distribution. Specifically, we use an engineered tissue graft platform that replicates the in vivo microenvironment, and provide our data to validate that this culture platform is viable for producing stem cells that have better stem cell distribution than with the Petri dish culture system.

  1. Genome-wide RNAi screens in human brain tumor isolates reveal a novel viability requirement for PHF5A.

    Science.gov (United States)

    Hubert, Christopher G; Bradley, Robert K; Ding, Yu; Toledo, Chad M; Herman, Jacob; Skutt-Kakaria, Kyobi; Girard, Emily J; Davison, Jerry; Berndt, Jason; Corrin, Philip; Hardcastle, Justin; Basom, Ryan; Delrow, Jeffery J; Webb, Thomas; Pollard, Steven M; Lee, Jeongwu; Olson, James M; Paddison, Patrick J

    2013-05-01

    To identify key regulators of human brain tumor maintenance and initiation, we performed multiple genome-wide RNAi screens in patient-derived glioblastoma multiforme (GBM) stem cells (GSCs). These screens identified the plant homeodomain (PHD)-finger domain protein PHF5A as differentially required for GSC expansion, as compared with untransformed neural stem cells (NSCs) and fibroblasts. Given PHF5A's known involvement in facilitating interactions between the U2 snRNP complex and ATP-dependent helicases, we examined cancer-specific roles in RNA splicing. We found that in GSCs, but not untransformed controls, PHF5A facilitates recognition of exons with unusual C-rich 3' splice sites in thousands of essential genes. PHF5A knockdown in GSCs, but not untransformed NSCs, astrocytes, or fibroblasts, inhibited splicing of these genes, leading to cell cycle arrest and loss of viability. Notably, pharmacologic inhibition of U2 snRNP activity phenocopied PHF5A knockdown in GSCs and also in NSCs or fibroblasts overexpressing MYC. Furthermore, PHF5A inhibition compromised GSC tumor formation in vivo and inhibited growth of established GBM patient-derived xenograft tumors. Our results demonstrate a novel viability requirement for PHF5A to maintain proper exon recognition in brain tumor-initiating cells and may provide new inroads for novel anti-GBM therapeutic strategies. PMID:23651857

  2. BRAIN TUMOR CLASSIFICATION USING NEURAL NETWORK BASED METHODS

    OpenAIRE

    Kalyani A. Bhawar*, Prof. Nitin K. Bhil

    2016-01-01

    MRI (Magnetic resonance Imaging) brain neoplasm pictures Classification may be a troublesome tasks due to the variance and complexity of tumors. This paper presents two Neural Network techniques for the classification of the magnetic resonance human brain images. The proposed Neural Network technique consists of 3 stages, namely, feature extraction, dimensionality reduction, and classification. In the first stage, we have obtained the options connected with tomography pictures victimization d...

  3. Immunocytochemical Studies of Aquaporin 4, Kir4.1, and α1-syntrophin in the Astrocyte Endfeet of Mouse Brain Capillaries

    International Nuclear Information System (INIS)

    One of the most important physiological roles of brain astrocytes is the maintenance of extracellular K+ concentration by adjusting the K+ influx and K+ efflux. The inwardly rectifying K+ channel Kir4.1 has been identified as an important member of K+ channels and is highly concentrated in glial endfeet membranes. Aquaporin (AQP) 4 is another abundantly expressed molecule in astrocyte endfeet membranes. We examined the ultrastructural localization of Kir4.1, AQP4, α1-syntrophin, and β-spectrin molecules to understand the functional role(s) of Kir4.1 and AQP4. Immunogold electron microscopy of these molecules showed that the signals of these molecules were present along the plasma membranes of astrocyte endfeet. Double immunogold electron microscopy showed frequent co-localization in the combination of molecules of Kir4.1 and AQP4, Kir4.1 and α1-syntrophin, and AQP4 and α1-syntrophin, but not those of AQP4 and β-spectrin. Our results support biochemical evidence that both Kir4.1 and AQP4 are associated with α1-syntrophin by way of postsynaptic density-95, Drosophila disc large protein, and the Zona occludens protein I protein-interaction domain. Co-localization of AQP4 and Kir4.1 may indicate that water flux mediated by AQP4 is associated with K+ siphoning

  4. Staging Childhood Brain and Spinal Cord Tumors

    Science.gov (United States)

    ... tests to check the brain, spinal cord, and nerve function. The exam checks a person’s mental status, coordination, and ability to walk normally, and how well the muscles, senses, and reflexes work. This may also be called a neuro ...

  5. Brain tumors induced in rats by human adenovirus type 12

    Directory of Open Access Journals (Sweden)

    Murao,Tsuyoshi

    1974-02-01

    Full Text Available Oncogenesis of human adenovirus type 12 in the brain of rats was examined. Newborn rats of Sprague-Dawley and Donryu strains were injected intracranially with human adenovirus type 12. The incidence of intracranial tumors was 91% (30/33 in SpragueDawley and 56% (14/25 in Donryu rats. Except for one tumor nodule located in the parietal cortex of a Sprague.Dawley rat, all tumors developed in the paraventricular areas or in the meninges. Tumors were quite similar histologically to those induced in hamsters and mice resembling the undifferentiated human brain tumors such as medulloblastoma, ependymoblastoma and embryonic gliomas. From the histological features and primary sites of tumor development, it is suggested that the tumors in the brain of rats induced by adenovirus type 12 originate from the embryonic cells in the paraventricular area and also from the undifferentiated supporting cells of the peripheral nerves in the leptomeninges.

  6. Delayed contrast extravasation MRI for depicting tumor and non-tumoral tissues in primary and metastatic brain tumors.

    Directory of Open Access Journals (Sweden)

    Leor Zach

    Full Text Available The current standard of care for newly diagnosed glioblastoma multiforme (GBM is resection followed by radiotherapy with concomitant and adjuvant temozolomide. Recent studies suggest that nearly half of the patients with early radiological deterioration post treatment do not suffer from tumor recurrence but from pseudoprogression. Similarly, a significant number of patients with brain metastases suffer from radiation necrosis following radiation treatments. Conventional MRI is currently unable to differentiate tumor progression from treatment-induced effects. The ability to clearly differentiate tumor from non-tumoral tissues is crucial for appropriate patient management. Ten patients with primary brain tumors and 10 patients with brain metastases were scanned by delayed contrast extravasation MRI prior to surgery. Enhancement subtraction maps calculated from high resolution MR images acquired up to 75 min after contrast administration were used for obtaining stereotactic biopsies. Histological assessment was then compared with the pre-surgical calculated maps. In addition, the application of our maps for prediction of progression was studied in a small cohort of 13 newly diagnosed GBM patients undergoing standard chemoradiation and followed up to 19.7 months post therapy. The maps showed two primary enhancement populations: the slow population where contrast clearance from the tissue was slower than contrast accumulation and the fast population where clearance was faster than accumulation. Comparison with histology confirmed the fast population to consist of morphologically active tumor and the slow population to consist of non-tumoral tissues. Our maps demonstrated significant correlation with perfusion-weighted MR data acquired simultaneously, although contradicting examples were shown. Preliminary results suggest that early changes in the fast volumes may serve as a predictor for time to progression. These preliminary results suggest that

  7. Boron neutron capture therapy for children with malignant brain tumor

    International Nuclear Information System (INIS)

    Among the 131 cases with brain tumors treated by boron-neutron capture therapy (BNCT), seventeen were children. Eight supratentorial tumors included five astrocytomas(grade 2-4), two primitive neuroectodermal tumors (PNET) and one rhabdomyosarcoma. Seven pontine tumors included one astrocytoma, one PNET and 5 unverified gliomas. Two cerebellar tumors (PNET and astrocytoma) were also treated. All pontine tumors showed remarkable decrease in size after BNCT. However, most of them showed regrowth of the tumors because the neutrons were insufficient due to the depth. Four cases with cerebral tumor died of remote cell dissemination, although they all responded to BNCT. One of them survived 7 years after repeated BNCTs. An 11 years old girl with a large astrocytoma in the right frontal lobe has lived more than 11 years and is now a draftswoman at a civil engineering company after graduating from a technical college. An 8 years old girl with an astrocytoma in the left occipital lobe has no recurrence of the tumor for 2 years and attends on elementary school without mental and physical problems. Two children (one year old girl and four years old boy) with cerebellar tumors have shown showed an excellent growth after BNCT and had no neurological deficits. Mental and physical development in patients treated by BNCT is usually better than that in patients treated by conventional radiotherapy. (author)

  8. IMPLEMENTATION OF BRAIN TUMOR IDENTIFICATION USING SVM AND CLASSIFICATION USING BAYESIAN CLASSIFIER IN MRI IMAGES

    OpenAIRE

    Sree Sankar.J*, R.A. Isabel

    2016-01-01

    Brain tumors are one of the deadly diseases. Identifying the type of the brain tumor is very essential for the planning of treatment and surgery. Early detection and classification of the tumors will increase the chances of survival. In this paper we propose a methodology for the detection and classification of brain tumors from Magnetic Resonance Imaging (MRI) scans. Here for the tumor detection Support Vector Machine (SVM) is used and for classification of tumor Bayesian classifier is used....

  9. Effect of tumor resection on the characteristics of functional brain networks

    NARCIS (Netherlands)

    Wang, H.; Douw, L.; Hernández, J.M.; Reijneveld, J.C.; Stam, C.J.; Van Mieghem, P.

    2010-01-01

    Brain functioning such as cognitive performance depends on the functional interactions between brain areas, namely, the functional brain networks. The functional brain networks of a group of patients with brain tumors are measured before and after tumor resection. In this work, we perform a weighted

  10. American brain tumor patients treated with BNCT in Japan

    International Nuclear Information System (INIS)

    The purpose of this work is to establish and maintain a database for patients from the United States who have received BNCT in Japan for malignant gliomas of the brain. This database will serve as a resource for the DOE to aid in decisions relating to BNCT research in the United States, as well as assisting the design and implementation of clinical trials of BNCT for brain cancer patients in this country. The database will also serve as an information resource for patients with brain tumors and their families who are considering this form of therapy

  11. American brain tumor patients treated with BNCT in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Laramore, G.E.; Griffin, B.R.; Spence, A.

    1995-11-01

    The purpose of this work is to establish and maintain a database for patients from the United States who have received BNCT in Japan for malignant gliomas of the brain. This database will serve as a resource for the DOE to aid in decisions relating to BNCT research in the United States, as well as assisting the design and implementation of clinical trials of BNCT for brain cancer patients in this country. The database will also serve as an information resource for patients with brain tumors and their families who are considering this form of therapy.

  12. Development of multifunctional nanoparticles for brain tumor diagnosis and therapy

    Science.gov (United States)

    Veiseh, Omid

    Magnetic nanoparticles (MNPs) represent a class of non-invasive imaging agents developed for magnetic resonance (MR) imaging and drug delivery. MNPs have traditionally been developed for disease imaging via passive targeting, but recent advances in nanotechnology have enabled cellular-specific targeting, drug delivery and multi-modal imaging using these nanoparticles. Opportunities now exist to engineer MNP with designated features (e.g., size, coatings, and molecular functionalizations) for specific biomedical applications. The goal of this interdisciplinary research project is to develop targeting multifunctional nanoparticles, serving as both contrast agents and drug carriers that can effectively pass biological barriers, for diagnosis, staging and treatment of brain tumors. The developed nanoparticle system consists of a superparamagnetic iron oxide nanoparticle core (NP) and a shell comprised of biodegradable polymers such as polyethylene glycol (PEG) and chitosan. Additionally, near-infrared fluorescing (NIRF) molecules were integrated onto the NP shell to enable optical detection. Tumor targeting was achieved by the addition of chlorotoxin, a peptide with that has high affinity to 74 out of the 79 classifications of primary brain tumors and ability to illicit a therapeutic effect. This novel NP system was tested both in vitro and in vivo and was shown to specifically target gliomas in tissue culture and medulloblastomas in transgenic mice with an intact blood brain barriers (BBB), and delineate tumor boundaries in both MR and optical imaging. Additionally, the therapeutic potential of this NP system was explored in vitro, which revealed a unique nanoparticle-enabled pathway that enhances the therapeutic potential of bound peptides by promoting the internalization of membrane bound cell surface receptors. This NP system was further modified with siRNA and evaluated as a carrier for brain tumor targeted gene therapy. Most significantly, the evaluation of

  13. Dynamic Quantitative T1 Mapping in Orthotopic Brain Tumor Xenografts

    Directory of Open Access Journals (Sweden)

    Kelsey Herrmann

    2016-04-01

    Full Text Available Human brain tumors such as glioblastomas are typically detected using conventional, nonquantitative magnetic resonance imaging (MRI techniques, such as T2-weighted and contrast enhanced T1-weighted MRI. In this manuscript, we tested whether dynamic quantitative T1 mapping by MRI can localize orthotopic glioma tumors in an objective manner. Quantitative T1 mapping was performed by MRI over multiple time points using the conventional contrast agent Optimark. We compared signal differences to determine the gadolinium concentration in tissues over time. The T1 parametric maps made it easy to identify the regions of contrast enhancement and thus tumor location. Doubling the typical human dose of contrast agent resulted in a clearer demarcation of these tumors. Therefore, T1 mapping of brain tumors is gadolinium dose dependent and improves detection of tumors by MRI. The use of T1 maps provides a quantitative means to evaluate tumor detection by gadolinium-based contrast agents over time. This dynamic quantitative T1 mapping technique will also enable future quantitative evaluation of various targeted MRI contrast agents.

  14. Cyclosporin safety in a simplified rat brain tumor implantation model

    Directory of Open Access Journals (Sweden)

    Francisco H. C. Felix

    2012-01-01

    Full Text Available Brain cancer is the second neurological cause of death. A simplified animal brain tumor model using W256 (carcinoma 256, Walker cell line was developed to permit the testing of novel treatment modalities. Wistar rats had a cell tumor solution inoculated stereotactically in the basal ganglia (right subfrontal caudate. This model yielded tumor growth in 95% of the animals, and showed absence of extracranial metastasis and systemic infection. Survival median was 10 days. Estimated tumor volume was 17.08±6.7 mm³ on the 7th day and 67.25±19.8 mm³ on 9th day post-inoculation. Doubling time was 24.25 h. Tumor growth induced cachexia, but no hematological or biochemical alterations. This model behaved as an undifferentiated tumor and can be promising for studying tumor cell migration in the central nervous system. Dexamethasone 3.0 mg/kg/day diminished significantly survival in this model. Cyclosporine 10 mg/kg/day administration was safely tolerated.

  15. Application of nanoparticles in brain tumor treatment

    CERN Document Server

    Caruso, Gerardo

    2012-01-01

    Despite progress in surgery, radiotherapy, and chemotherapy, an effective treatment of gliomas does not yet exist. This new monograph in the ASME-Momentum Press series on Biomedical & Nanomedical Technologies book shows how nanotechnology could be used both to improve the treatment efficacy and to reduce the adverse side effects. It will explain how nanotechnology-based approaches to targeted delivery of drugs across the brain-blood barrier may potentially be engineered to carry out specific functions as needed.

  16. Brain hyaluronan binding protein inhibits tumor growth

    Institute of Scientific and Technical Information of China (English)

    高锋; 曹曼林; 王蕾

    2004-01-01

    Background Great efforts have been made to search for the angiogenic inhibitors in avascular tissues. Several proteins isolated from cartilage have been proved to have anti-angiogenic or anti-tumour effects. Because cartilage contains a great amount of hyaluronic acid (HA) oligosaccharides and abundant HA binding proteins (HABP), therefore, we speculated that HABP might be one of the factors regulating vascularization in cartilage or anti-angiogenesis in tumours. The purpose of this research was to evaluale the effects of hyaluronan binding protein on inhibiting tumour growth both in vivo and vitro. Methods A unique protein termed human brain hyaluronan (HA) binding protein (b-HABP) was cloned from human brain cDNA library. MDA-435 human breast cancer cell line was chosen as a transfectant. The in vitro underlying mechanisms were investigated by determining the possibilities of MDA-435/b-HABP colony formation on soft agar, the effects of the transfectant on the proliferation of endothelial cells and the expression levels of caspase 3 and FasL from MDA-435/b-HABP. The in vivo study included tumour growth on the chorioallantoic membrane (CAM) of chicken embryos and nude mice. Results Colony formation assay revealed that the colonies formed by MDA-435/b-HABP were greatly reduced compared to mock transfectants. The conditioned media from MDA-435/b-HABP inhibited the growth of endothelial cells in culture. Caspase 3 and FasL expressions were induced by MDA-435/b-HABP. The size of tumours of MDA-435/b-HABP in both CAM and nude mice was much smaller than that of MDA-435 alone. Conclusions Human brain hyaluronan binding protein (b-HABP) may represent a new kind of naturally existing anti-tumour substance. This brain-derived glycoprotein may block tumour growth by inducing apoptosis of cancer cells or by decreasing angiogenesis in tumour tissue via inhibiting proliferation of endothelial cells.

  17. Spectroscopy of brain tumors; Spektroskopie bei Hirntumoren

    Energy Technology Data Exchange (ETDEWEB)

    Raab, Peter; Lanfermann, Heinrich [Medizinische Hochschule Hannover (Germany). Inst. fuer Diagnostische und Interventionelle Neuroradiologie; Pilatus, Ulrich [Frankfurt Univ., Frankfurt am Main (Germany). Inst. fuer Neuroradiologie

    2008-09-15

    Metabolic imaging with NMR-spectroscopy has become a diagnostic tool that is used for the examination of cerebral pathologies. It is a non-invasive technique, which can detect and quantify biochemical changes. This paper describes the history of NMR-spectroscopy, its technical basis and possible areas of use for tumor diagnostics. An overview of the literature is given and upcoming developments are mentioned. (orig.)

  18. Gd-DTPA-enhanced MR imaging for metastatic brain tumors

    International Nuclear Information System (INIS)

    The present series consists of 24 patients with brain metastasis smaller than 10 mm in diameter demonstrated on Gd-DTPA enhanced MR imaging (Gd-MRI). All patients underwent contrast-enhanced (CE) CT to be compared with Gd-MRI in size, number and detectability. The primary lesions of the series included 18 patients with lung cancer (9 with adenocarcinoma, 4 with small cell cancer, 3 with squamous cell cancer and 2 with large cell cancer), 4 with breast cancer, and each 1 with parotid cancer and renal cell carcinoma. All 24 patients except one who underwent surgery were treated with radiation therapy. In 13 patients examined by Gd-MRI and CE-CT both before and after the brain irradiation, therapeutic effect was estimated on each diagnostic imaging comparatively. In regard to size of brain metastases of 24 patients, 91 lesions smaller than 5 mm in diameter were detected by Gd-MRI but only 15 by CE-CT. Three of all patients, no brain metastasis was found on CE-CT. In 6 patients estimated as CR (complete remission) by CE-CT after brain irradiation, Gd-MRI evidenced tumor residues in 5 patients to alter the score of therapeutic effect as PR (partial remission). The difference in therapeutic effects confirmed by Gd-MRI was noted according to histological results and size of metastasis. The most radiosensitive tumor was small cell lung cancer, of which brain metastases smaller than 5 mm in diameter completely disappeared after 20∼50 Gy irradiation. Prophylactic whole brain irradiation has been an alternative indication for small cell lung cancer when CT showed no evidence of brain metastasis. However, our data strongly suggest that the small or tiny brain metastases negative on CE-CT will become new subjects of 'radical' radiotherapy. The higher sensitivity of Gd-MRI for detecting brain metastasis may propose new clinical prospects in staging, planning of therapy and estimation of therapeutic effect. (author)

  19. Radiotherapy combined with Tegafur (FT-207s) for brain tumors

    International Nuclear Information System (INIS)

    5-Fluorouracil (5-FU) has anti-tumor effects as an anti-metabolite, but it cannot pass the Blood-Brain-Barrier (BBB). FT-207 a masked-compound of 5-FU, is easily lipid soluble and is able to pass the BBB. Twenty eight patients of primary brain tumor and 8 patients of metastatic brain tumor were treated with irradiation combined with 750 mg of FT-207 suppository. Twenty four patients of primary brain tumor were treated only with irradiation as control. The mean survival time was 20.4 +- 11.8 months for the combined therapy group and 17.6 +- 8.6 months for the control. The concentration of FT-207 and 5-FU in serum and in cerebrospinal fluid (CSF) was investigated after administration of 750 mg of FT-207 suppository per annum. The maximum concentration of FT-207 and of 5-FU in serum was 20.4 +- 11.8 mcg/ml and 0.06 +- 0.02 mcg/ml, respectively. There were observed several side effects, such as anorexia, nausea, exanthema and etc. These side effects were not so great as to interrupt the therapy at the dose level of 750 mg of FT-207. However, at the dose of 1500 mg, one case showed disturbance of consciousness, to which attention should be called. (author)

  20. Genetic abnormality predicts benefit for a rare brain tumor

    Science.gov (United States)

    A clinical trial has shown that addition of chemotherapy to radiation therapy leads to a near doubling of median survival time in patients with a form of brain tumor (oligodendroglioma) that carries a chromosomal abnormality called the 1p19q co-deletion.

  1. Learning Profiles of Survivors of Pediatric Brain Tumors

    Science.gov (United States)

    Barkon, Beverly

    2009-01-01

    By 2010 it is predicted that one in 900 adults will be survivors of some form of pediatric cancer. The numbers are somewhat lower for survivors of brain tumors, though their numbers are increasing. Schools mistakenly believe that these children easily fit pre-existing categories of disability. Though these students share some of the…

  2. Automated 3D Brain Tumor Edema Segmentation in FLAIR MRI

    Czech Academy of Sciences Publication Activity Database

    Dvořák, P.; Bartušek, Karel

    Vol. S1. Berlin : Springer-Verlag, 2013, s. 489. ISSN 1352-8661. [ESMRMB 2013. Congress. Tolouse (FR), 03.10.2013-05.10.2013] Institutional support: RVO:68081731 Keywords : Automated 3D * brain tumor edema segmentation * FLAIR MRI Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  3. Association Between PARP1 Single Nucleotide Polymorphism and Brain Tumors.

    Science.gov (United States)

    Wang, Hong; Zhang, Kun; Qin, Haifeng; Yang, Lin; Zhang, Liyu; Cao, Yanyan

    2016-05-01

    To systematically evaluate the association between poly(ADP-ribose) polymerase 1 (PARP1) rs1136410 T>C and brain tumor risk, a meta-analysis has been carried out. We performed a meta-analysis of 2004 brain tumor patients and 2944 controls by use of STATA version 12.0 to determine whether the risk of brain tumors was associated with the genotypes or alleles of rs1136410 T>C. We found a significantly decreased risk (ranging from 0.18- to 0.16-fold) in the dominant model (OR = 0.84, 95 % CI = 0.75-0.95), the C vs. T model (OR = 0.82, 95 % CI = 0.74-0.91), and the CT vs. TT model (OR = 0.86, 95 % CI = 0.76-0.98). The same genetic models demonstrated noteworthy associations when analysis was restrained to glioma (OR = 0.85, 95 % CI = 0.75-0.96; OR = 0.83, 95 % CI = 0.74-0.92; OR = 0.87, 95 % CI = 0.76-0.99, respectively). This meta-analysis suggests that PARP1 rs1136410 T>C may play a significant role in the protection against the development of brain tumors and glioma. PMID:25911198

  4. What Are Brain and Spinal Cord Tumors in Children?

    Science.gov (United States)

    ... tissues and cells, which can develop into different types of tumors. Neurons (nerve cells): These are the most important cells ... as long as several feet. Unlike many other types of cells that can grow and divide to repair damage from injury or disease, neurons in the brain and spinal cord largely stop ...

  5. Epigenetic Regulation of HIV-1 Latency in Astrocytes

    OpenAIRE

    Narasipura, Srinivas D.; Kim, Stephanie; Al-Harthi, Lena

    2014-01-01

    HIV infiltrates the brain at early times postinfection and remains latent within astrocytes and macrophages. Because astrocytes are the most abundant cell type in the brain, we evaluated epigenetic regulation of HIV latency in astrocytes. We have shown that class I histone deacetylases (HDACs) and a lysine-specific histone methyltransferase, SU(VAR)3-9, play a significant role in silencing of HIV transcription in astrocytes. Our studies add to a growing body of evidence demonstrating that ast...

  6. Tumor angiogenesis in rabbit VX2 brain tumor: model establishment, pathologic study and preliminary imaging observation

    International Nuclear Information System (INIS)

    Objective: To establish a stable implanted model of VX2 rabbit brain tumor, and to evaluate the pathological and imaging features and tumor angiogenesis. Methods: Thirty New Zealand white rabbits were implanted with 100 μl viable VX2 tumor cells (107/ml) through a hole 5 mm to the right of the sagittal suture and 5 mm posterior to the coronal suture bored by a dental drill. MRI was performed every 2 days after 7 days of implantation to evaluate the growth of the tumor, and perfusion CT studies were performed in different days of tumor growth. After that the animals were sacrificed on days 14, 18, 22, 26, and 30 of tumor implantation. 2% Evans blue (2 ml/kg) was given intravenously in 16 of these animals 1 hour prior to sacrifice to detect the breakdown of the blood-brain barrier (BBB). The specimens of the rabbit brains were examined pathologically and histologically. VEGF and MVD were evaluated in immunohistochemical examination. Results: Of the 22 animals included into the study, the tumor grew in 20 animals, which could be seen clearly on MR imaging. Pathologic examination showed characteristics of squamous carcinoma. VEGF was expressed in all tumors with the mean rate of positive cells of (52.51 ± 19.15)% (19.5%-92.9%). Mean MVD was (51.30 ± 14.42) pice piece/microscope (25-81 pice piece/microscope). Using Pearson's linear correlation analysis, positive correlation was found between tumor growth time and volume (r=0.791, P=0.000), between MVD and tumor growth time (r=0.875, P=0.000), and between MVD and tumor volume (r=0.901, P=0.000), respectively. Spearman's rank correlation analysis showed positive correlation between VEGF grade and blue stain of the tumor (rs=0.594, P=0.015). Conclusion: A stable model of VX2 rabbit brain tumor has been established with the method of skull drilling. The method was simple and easy to use, with a high tumor growth rate and remarkable angiogenesis. The model is helpful for the pathological and radiological study of tumor

  7. Intracellular Polyamines Enhance Astrocytic Coupling

    OpenAIRE

    Benedikt, Jan; Inyushin, Mikhail; Yuriy V Kucheryavykh; Rivera, Yomarie; Kucheryavykh, Lilia Y.; Nichols, Colin G.; Eaton, Misty J.; Skatchkov, Serguei N.

    2012-01-01

    Spermine (SPM) and spermidine (SPD), endogenous polyamines (PA) with the ability to modulate various ion channels and receptors in the brain, exert neuroprotective, antidepressant, antioxidant and other effects in vivo such as increasing longevity. These PA are preferably accumulated in astrocytes, and we hypothesized that SPM increases glial intercellular communication by interacting with glial gap junctions. Results obtained in situ, using Lucifer yellow propagation in the astrocytic syncit...

  8. Cerenkov and radioluminescence imaging of brain tumor specimens during neurosurgery

    Science.gov (United States)

    Spinelli, Antonello Enrico; Schiariti, Marco P.; Grana, Chiara M.; Ferrari, Mahila; Cremonesi, Marta; Boschi, Federico

    2016-05-01

    We presented the first example of Cerenkov luminescence imaging (CLI) and radioluminescence imaging (RLI) of human tumor specimens. A patient with a brain meningioma localized in the left parietal region was injected with 166 MBq of Y90-DOTATOC the day before neurosurgery. The specimens of the tumor removed during surgery were imaged using both CLI and RLI using an optical imager prototype developed in our laboratory. The system is based on a cooled electron multiplied charge coupled device coupled with an f/0.95 17-mm C-mount lens. We showed for the first time the possibility of obtaining CLI and RLI images of fresh human brain tumor specimens removed during neurosurgery.

  9. The neuron-astrocyte-microglia triad in normal brain ageing and in a model of neuroinflammation in the rat hippocampus.

    Directory of Open Access Journals (Sweden)

    Francesca Cerbai

    Full Text Available Ageing is accompanied by a decline in cognitive functions; along with a variety of neurobiological changes. The association between inflammation and ageing is based on complex molecular and cellular changes that we are only just beginning to understand. The hippocampus is one of the structures more closely related to electrophysiological, structural and morphological changes during ageing. In the present study we examined the effect of normal ageing and LPS-induced inflammation on astroglia-neuron interaction in the rat hippocampus of adult, normal aged and LPS-treated adult rats. Astrocytes were smaller, with thicker and shorter branches and less numerous in CA1 Str. radiatum of aged rats in comparison to adult and LPS-treated rats. Astrocyte branches infiltrated apoptotic neurons of aged and LPS-treated rats. Cellular debris, which were more numerous in CA1 of aged and LPS-treated rats, could be found apposed to astrocytes processes and were phagocytated by reactive microglia. Reactive microglia were present in the CA1 Str. Radiatum, often in association with apoptotic cells. Significant differences were found in the fraction of reactive microglia which was 40% of total in adult, 33% in aged and 50% in LPS-treated rats. Fractalkine (CX3CL1 increased significantly in hippocampus homogenates of aged and LPS-treated rats. The number of CA1 neurons decreased in aged rats. In the hippocampus of aged and LPS-treated rats astrocytes and microglia may help clearing apoptotic cellular debris possibly through CX3CL1 signalling. Our results indicate that astrocytes and microglia in the hippocampus of aged and LPS-infused rats possibly participate in the clearance of cellular debris associated with programmed cell death. The actions of astrocytes may represent either protective mechanisms to control inflammatory processes and the spread of further cellular damage to neighboring tissue, or they may contribute to neuronal damage in pathological conditions.

  10. Cytokine Gene Polymorphisms in Egyptian Cases with Brain Tumors

    International Nuclear Information System (INIS)

    Background: Cytokines are proposed to play important roles in brain tumor biology as well as neuro degeneration or impaired neuronal function. Objectives: This work aimed to check the association of polymorphisms of cytokine genes in Egyptian cases with brain tumors. Methods: This work included 45 cases affected by brain tumors diagnosed as 24 benign and 21 malignant. Their median age was 45 years, and they were 20 males and 25 females. These cases were taken randomly from the Neurosurgery Department of Mansoura University Hospital, Egypt. Case genotypes were compared to 98 healthy unrelated controls from the same locality. DNA was amplified using PCR utilizing sequence specific primers (SSP) for detection of polymorphisms related to TNF-a-308 (G/A), IL-10-1082 (G/A), IL-6-174 (G/C) and IL-1Ra (VNTR) genes. Results: Cases affected with benign brain tumors showed a significant higher frequency of IL-10-1082 A/A [odds ratio (OR=8.0), p<0.001] and IL-6-174 C/C (OR=6.3, p=0.002) homozygous genotypes as compared to controls. Malignant cases, on the other hand, showed significantly higher frequency of IL-6-174 C/C (OR =4.8, p=0.002) homozygous genotype and TNF-a-308 A/A (OR=4.9, p<0.001) homozygous genotype when compared to controls. In the meantime, all cases showed no significant difference regarding the distribution of IL-1Ra VNTR genotype polymorphism compared to controls. Conclusions: Cytokine gene polymorphisms showed a pattern of association with brain tumors which may have potential impact on family counseling and disease management.

  11. Simulation of brain tumor resection in image-guided neurosurgery

    Science.gov (United States)

    Fan, Xiaoyao; Ji, Songbai; Fontaine, Kathryn; Hartov, Alex; Roberts, David; Paulsen, Keith

    2011-03-01

    Preoperative magnetic resonance images are typically used for neuronavigation in image-guided neurosurgery. However, intraoperative brain deformation (e.g., as a result of gravitation, loss of cerebrospinal fluid, retraction, resection, etc.) significantly degrades the accuracy in image guidance, and must be compensated for in order to maintain sufficient accuracy for navigation. Biomechanical finite element models are effective techniques that assimilate intraoperative data and compute whole-brain deformation from which to generate model-updated MR images (uMR) to improve accuracy in intraoperative guidance. To date, most studies have focused on early surgical stages (i.e., after craniotomy and durotomy), whereas simulation of more complex events at later surgical stages has remained to be a challenge using biomechanical models. We have developed a method to simulate partial or complete tumor resection that incorporates intraoperative volumetric ultrasound (US) and stereovision (SV), and the resulting whole-brain deformation was used to generate uMR. The 3D ultrasound and stereovision systems are complimentary to each other because they capture features deeper in the brain beneath the craniotomy and at the exposed cortical surface, respectively. In this paper, we illustrate the application of the proposed method to simulate brain tumor resection at three temporally distinct surgical stages throughout a clinical surgery case using sparse displacement data obtained from both the US and SV systems. We demonstrate that our technique is feasible to produce uMR that agrees well with intraoperative US and SV images after dural opening, after partial tumor resection, and after complete tumor resection. Currently, the computational cost to simulate tumor resection can be up to 30 min because of the need for re-meshing and the trial-and-error approach to refine the amount of tissue resection. However, this approach introduces minimal interruption to the surgical workflow

  12. Anti-angiogenic therapy in pediatric brain tumors : An effective strategy?

    NARCIS (Netherlands)

    Sie, Mariska; den Dunnen, Wilfred F. A.; Hoving, Eelco W.; de Bont, Eveline S. J. M.

    2014-01-01

    Brain tumors are still the leading cause of cancer morbidity and mortality among children, despite different therapeutic options including neurosurgery, chemotherapy and radiation. As angiogenesis is highly crucial in brain tumor growth and progression, numerous clinical trials evaluating diverse an

  13. Chemo-radiotherapy for malignant brain tumors

    International Nuclear Information System (INIS)

    Malignant gliomas: Randomized clinical trials conducted in the USA showed that radiotherapy plus chemotherapy with nitrosoureas offered a long-term survival advantage to patients younger than 60 years old with malignant gliomas. Combination chemotherapy, such as procarbazine/CCNU/vincristine (PCV) must be tested further, and intra-arterial chemotherapy with nitrosoureas offered no survival advantage. Combination chemotherapy with PCV showed efficacy for patients with anaplastic oligodendroglioma and anaplastic oligoastrocytoma. Medulloblastoma: The addition of chemotherapy to radiotherapy improved the survival of patients with poor risk medulloblastoma, and may reduce the required craniospinal radiation dose in patients with good risk medulloblastoma. Primary CNS lymphoma (PCNSL): Combination of chemotherapy with high-dose MTX and radiotherapy improved survival of patients with PCNSL; however, the neurotoxicity produced by this treatment modality is a serious problem in older patients. Intracranial germ cell tumors: The addition of chemotherapy to radiotherapy may produce long term survival with good quality of life in patients with germinoma. Neoadjuvant therapy consisting of chemotherapy and radiotherapy followed by complete surgical excision improved survival of patients with intracranial nongerminomatous germ cell tumors. (author)

  14. Chemo-radiotherapy for malignant brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Kochi, Masato; Ushio, Yukitaka [Kumamoto Univ. (Japan). School of Medicine

    2002-05-01

    Malignant gliomas: Randomized clinical trials conducted in the USA showed that radiotherapy plus chemotherapy with nitrosoureas offered a long-term survival advantage to patients younger than 60 years old with malignant gliomas. Combination chemotherapy, such as procarbazine/CCNU/vincristine (PCV) must be tested further, and intra-arterial chemotherapy with nitrosoureas offered no survival advantage. Combination chemotherapy with PCV showed efficacy for patients with anaplastic oligodendroglioma and anaplastic oligoastrocytoma. Medulloblastoma: The addition of chemotherapy to radiotherapy improved the survival of patients with poor risk medulloblastoma, and may reduce the required craniospinal radiation dose in patients with good risk medulloblastoma. Primary CNS lymphoma (PCNSL): Combination of chemotherapy with high-dose MTX and radiotherapy improved survival of patients with PCNSL; however, the neurotoxicity produced by this treatment modality is a serious problem in older patients. Intracranial germ cell tumors: The addition of chemotherapy to radiotherapy may produce long term survival with good quality of life in patients with germinoma. Neoadjuvant therapy consisting of chemotherapy and radiotherapy followed by complete surgical excision improved survival of patients with intracranial nongerminomatous germ cell tumors. (author)

  15. Lysosomal iron liberation is responsible for the vulnerability of brain microglial cells to iron oxide nanoparticles: comparison with neurons and astrocytes.

    Science.gov (United States)

    Petters, Charlotte; Thiel, Karsten; Dringen, Ralf

    2016-04-01

    Iron oxide nanoparticles (IONPs) are used for various biomedical and neurobiological applications. Thus, detailed knowledge on the accumulation and toxic potential of IONPs for the different types of brain cells is highly warranted. Literature data suggest that microglial cells are more vulnerable towards IONP exposure than other types of brain cells. To investigate the mechanisms involved in IONP-induced microglial toxicity, we applied fluorescent dimercaptosuccinate-coated IONPs to primary cultures of microglial cells. Exposure to IONPs for 6 h caused a strong concentration-dependent increase in the microglial iron content which was accompanied by a substantial generation of reactive oxygen species (ROS) and by cell toxicity. In contrast, hardly any ROS staining and no loss in cell viability were observed for cultured primary astrocytes and neurons although these cultures accumulated similar specific amounts of IONPs than microglia. Co-localization studies with lysotracker revealed that after 6 h of incubation in microglial cells, but not in astrocytes and neurons, most IONP fluorescence was localized in lysosomes. ROS formation and toxicity in IONP-treated microglial cultures were prevented by neutralizing lysosomal pH by the application of NH4Cl or Bafilomycin A1 and by the presence of the iron chelator 2,2'-bipyridyl. These data demonstrate that rapid iron liberation from IONPs at acidic pH and iron-catalyzed ROS generation are involved in the IONP-induced toxicity of microglia and suggest that the relative resistance of astrocytes and neurons against acute IONP toxicity is a consequence of a slow mobilization of iron from IONPs in the lysosomal degradation pathway. PMID:26287375

  16. Isolation and Characterization of Ischemia-Derived Astrocytes (IDAs) with Ability to Transactivate Quiescent Astrocytes

    OpenAIRE

    Villarreal, Alejandro; Rosciszewski, Gerardo; Murta, Veronica; Cadena, Vanesa; Usach, Vanina; Dodes-Traian, Martin M.; Setton-Avruj, Patricia; Barbeito, Luis H.; Ramos, Alberto J.

    2016-01-01

    Reactive gliosis involving activation and proliferation of astrocytes and microglia, is a widespread but largely complex and graded glial response to brain injury. Astroglial population has a previously underestimated high heterogeneity with cells differing in their morphology, gene expression profile, and response to injury. Here, we identified a subset of reactive astrocytes isolated from brain focal ischemic lesions that show several atypical characteristics. Ischemia-derived astrocytes (I...

  17. Banking Brain Tumor Specimens Using a University Core Facility.

    Science.gov (United States)

    Bregy, Amade; Papadimitriou, Kyriakos; Faber, David A; Shah, Ashish H; Gomez, Carmen R; Komotar, Ricardo J; Egea, Sophie C

    2015-08-01

    Within the past three decades, the significance of banking human cancer tissue for the advancement of cancer research has grown exponentially. The purpose of this article is to detail our experience in collecting brain tumor specimens in collaboration with the University of Miami/Sylvester Tissue Bank Core Facility (UM-TBCF), to ensure the availability of high-quality samples of central nervous system tumor tissue for research. Successful tissue collection begins with obtaining informed consent from patients following institutional IRB and federal HIPAA guidelines, and it needs a well-trained professional staff and continued maintenance of high ethical standards and record keeping. Since starting in 2011, we have successfully banked 225 brain tumor specimens for research. Thus far, the most common tumor histology identified among those specimens has been glioblastoma (22.1%), followed by meningioma (18.1%). The majority of patients were White, non-Hispanics accounting for 45.1% of the patient population; Hispanic/Latinos accounted for 23%, and Black/African Americans accounted for 14%, which represent the particular population of the State of Florida according to the 2010 census data. The most common tumors found in each subgroup were as follows: Black/African American, glioblastoma and meningioma; Hispanic, metastasis and glioblastoma; White, glioblastoma and meningioma. The UM-TBCF is a valuable repository, offering high-quality tumor samples from a unique patient population. PMID:26280502

  18. Stereotactic interstitial brachytherapy for the treatment of oligodendroglial brain tumors

    International Nuclear Information System (INIS)

    We evaluated the treatment of oligodendroglial brain tumors with interstitial brachytherapy (IBT) using 125iodine seeds (125I) and analyzed prognostic factors. Between January 1991 and December 2010, 63 patients (median age 43.3 years, range 20.8-63.4 years) suffering from oligodendroglial brain tumors were treated with 125I IBT either as primary, adjuvantly after incomplete resection, or as salvage therapy after tumor recurrence. Possible prognostic factors influencing disease progression and survival were retrospectively investigated. The actuarial 2-, 5-, and 10-year overall and progression-free survival rates after IBT for WHO II tumors were 96.9, 96.9, 89.8 % and 96.9, 93.8, 47.3 %; for WHO III tumors 90.3, 77, 54.9 % and 80.6, 58.4, 45.9 %, respectively. Magnetic resonance imaging demonstrated complete remission in 2 patients, partial remission in 13 patients, stable disease in 17 patients and tumor progression in 31 patients. Median time to progression for WHO II tumors was 87.6 months and for WHO III tumors 27.8 months. Neurological status improved in 10 patients and remained stable in 20 patients, while 9 patients deteriorated. There was no treatment-related mortality. Treatment-related morbidity was transient in 11 patients. WHO II, KPS ≥ 90 %, frontal location, and tumor surface dose > 50 Gy were associated with increased overall survival (p ≤ 0.05). Oligodendroglioma and frontal location were associated with a prolonged progression-free survival (p ≤ 0.05). Our study indicates that IBT achieves local control rates comparable to surgery and radio-/chemotherapy treatment, is minimally invasive, and safe. Due to the low rate of side effects, IBT may represent an attractive option as part of a multimodal treatment schedule, being supplementary to microsurgery or as a salvage therapy after chemotherapy and conventional irradiation. (orig.)

  19. Differential MRI Diagnosis Between Brain Abscess and Necrotic or Cystic Brain Tumors Using Diffusion Weighted Images

    Directory of Open Access Journals (Sweden)

    Zinat Miabi

    2009-01-01

    Full Text Available "nIntroduction: Differentiating brain abscesses from cystic or necrotic tumors by CT or MR imaging can be difficult. Difficulties in the diagnosis of intracranial abscess are mainly due to the combination of often unspecified clinical findings and similarities in the morphologic appearance of some intracranial mass lesions, such as cystic gliomas, metastases, and brain abscesses. Diffusion-weighted imaging provides a way to evaluate the diffusion properties of water molecules in tissue and has been used for diseases such as ischemia, tumors, epilepsy, and white matter disorders. The goal of this study was to evaluate the diagnostic utility of diffusion MRI to differentiate between brain abscesses and necrotic or cystic brain tumors. "nMaterials and Methods: MRI was performed in 17 patients (12 men and five women; age range, 19–74 years [mean, 55 years] with necrotic lesions and MR imaging evidence of ring-shaped enhancement after the injection of contrast material .In addition to standard MR sequences diffusion weighted MRI with apparent coefficient (ADC maps. "nResults: Eleven patients had tumors, and six had pyogenic abscesses. The tumors were glioblastomas (five patients, anaplastic astrocytoma (three patients, metastases (three patients, and primary malignancy, including lung (2 and breast (1 cancer. Surgical or stereotactic biopsies were obtained, and histologic studies were performed in all except one case (case 5. In the cases of abscess, bacteriologic analysis was also conducted. None of these lesions appeared hemorrhagic on T1-weighted images. "nConclusion: Diffusion-weighted imaging is useful for differentiating brain abscess from cystic or necrotic brain tumor, which is often difficult with conventional MR imaging. Diffusion-weighted imaging is useful as an additional imaging technique for establishing the differential diagnosis between brain abscesses and cystic or necrotic brain tumors. It requires less imaging time and is more

  20. The Role of Surgery, Radiosurgery and Whole Brain Radiation Therapy in the Management of Patients with Metastatic Brain Tumors

    OpenAIRE

    CHAN, MICHAEL D.; Neal, Matthew T.; Ellis, Thomas L.

    2012-01-01

    Brain tumors constitute the most common intracranial tumor. Management of brain metastases has become increasingly complex as patients with brain metastases are living longer and more treatment options develop. The goal of this paper is to review the role of stereotactic radiosurgery (SRS), whole brain radiation therapy (WBRT), and surgery, in isolation and in combination, in the contemporary treatment of brain metastases. Surgery and SRS both offer management options that may help to optimiz...

  1. Radiation treatment of brain tumors: Concepts and strategies

    Energy Technology Data Exchange (ETDEWEB)

    Marks, J.E. (Loyola Univ. of Chicago Stritch School of Medicine, Maywood, IL (USA))

    1989-01-01

    Ionizing radiation has demonstrated clinical value for a multitude of CNS tumors. Application of the different physical modalities available has made it possible for the radiotherapist to concentrate the radiation in the region of the tumor with relative sparing of the surrounding normal tissues. Correlation of radiation dose with effect on cranial soft tissues, normal brain, and tumor has shown increasing effect with increasing dose. By using different physical modalities to alter the distribution of radiation dose, it is possible to increase the dose to the tumor and reduce the dose to the normal tissues. Alteration of the volume irradiated and the dose delivered to cranial soft tissues, normal brain, and tumor are strategies that have been effective in improving survival and decreasing complications. The quest for therapeutic gain using hyperbaric oxygen, neutrons, radiation sensitizers, chemotherapeutic agents, and BNCT has met with limited success. Both neoplastic and normal cells are affected simultaneously by all modalities of treatment, including ionizing radiation. Consequently, one is unable to totally depopulate a tumor without irreversibly damaging the normal tissues. In the case of radiation, it is the brain that limits delivery of curative doses, and in the case of chemical additives, it is other organ systems, such as bone marrow, liver, lung, kidneys, and peripheral nerves. Thus, the major obstacle in the treatment of malignant gliomas is our inability to preferentially affect the tumor with the modalities available. Until it is possible to directly target the neoplastic cell without affecting so many of the adjacent normal cells, the quest for therapeutic gain will go unrealized.72 references.

  2. Brain Tumor Susceptibility: the Role of Genetic Factors and Uses of Mouse Models to Unravel Risk

    OpenAIRE

    Reilly, Karlyne M.

    2009-01-01

    Brain tumors are relatively rare but deadly cancers, and present challenges in the determination of risk factors in the population. These tumors are inherently difficult to cure because of their protected location in the brain, with surgery, radiation and chemotherapy options carrying potentially lasting morbidity for patients and incomplete cure of the tumor. The development of methods to prevent or detect brain tumors at an early stage is extremely important to reduce damage to the brain fr...

  3. Caring for the brain tumor patient: Family caregiver burden and unmet needs

    OpenAIRE

    Schubart, Jane R.; Kinzie, Mable B.; Farace, Elana

    2008-01-01

    The rapid onset and progression of a brain tumor, cognitive and behavioral changes, and uncertainty surrounding prognosis are issues well known to health practitioners in neuro-oncology. We studied the specific challenges that family caregivers face when caring for patients experiencing the significant neurocognitive and neurobehavioral disorders associated with brain tumors. We selected 25 family caregivers of adult brain tumor patients to represent the brain tumor illness trajectory (crisis...

  4. Astrocyte-Specific Overexpression of Insulin-Like Growth Factor-1 Protects Hippocampal Neurons and Reduces Behavioral Deficits following Traumatic Brain Injury in Mice.

    Directory of Open Access Journals (Sweden)

    Sindhu K Madathil

    Full Text Available Traumatic brain injury (TBI survivors often suffer from long-lasting cognitive impairment that stems from hippocampal injury. Systemic administration of insulin-like growth factor-1 (IGF-1, a polypeptide growth factor known to play vital roles in neuronal survival, has been shown to attenuate posttraumatic cognitive and motor dysfunction. However, its neuroprotective effects in TBI have not been examined. To this end, moderate or severe contusion brain injury was induced in mice with conditional (postnatal overexpression of IGF-1 using the controlled cortical impact (CCI injury model. CCI brain injury produces robust reactive astrocytosis in regions of neuronal damage such as the hippocampus. We exploited this regional astrocytosis by linking expression of hIGF-1 to the astrocyte-specific glial fibrillary acidic protein (GFAP promoter, effectively targeting IGF-1 delivery to vulnerable neurons. Following brain injury, IGF-1Tg mice exhibited a progressive increase in hippocampal IGF-1 levels which was coupled with enhanced hippocampal reactive astrocytosis and significantly greater GFAP levels relative to WT mice. IGF-1 overexpression stimulated Akt phosphorylation and reduced acute (1 and 3d hippocampal neurodegeneration, culminating in greater neuron survival at 10d after CCI injury. Hippocampal neuroprotection achieved by IGF-1 overexpression was accompanied by improved motor and cognitive function in brain-injured mice. These data provide strong support for the therapeutic efficacy of increased brain levels of IGF-1 in the setting of TBI.

  5. Skull-stripping for Tumor-bearing Brain Images

    CERN Document Server

    Bauer, Stefan; Reyes, Mauricio

    2012-01-01

    Skull-stripping separates the skull region of the head from the soft brain tissues. In many cases of brain image analysis, this is an essential preprocessing step in order to improve the final result. This is true for both registration and segmentation tasks. In fact, skull-stripping of magnetic resonance images (MRI) is a well-studied problem with numerous publications in recent years. Many different algorithms have been proposed, a summary and comparison of which can be found in [Fennema-Notestine, 2006]. Despite the abundance of approaches, we discovered that the algorithms which had been suggested so far, perform poorly when dealing with tumor-bearing brain images. This is mostly due to additional difficulties in separating the brain from the skull in this case, especially when the lesion is located very close to the skull border. Additionally, images acquired according to standard clinical protocols, often exhibit anisotropic resolution and only partial coverage, which further complicates the task. There...

  6. Brain tumor stem cells as research and treatment targets

    International Nuclear Information System (INIS)

    Glioblastoma multiforme (GBM) is one of the most malignant forms of human cancer. Despite intensive treatment, the mean survival of GBM patients remains about 1 year. Recent cancer studies revealed that cancer tissues are pathologically heterogeneous and only a small population of cells has the specific ability to reinitiate cancer. This small cell population is called cancer stem cells (CSCs); in brain tumors these are known as brain tumor stem cells (BTSCs). The identification of BTSCs yielded new insights into chemo- and radioresistance, by which BTSCs can survive selectively and initiate recurrence. Research focused on BTSCs as treatment targets may contribute to the discovery of new therapeutic strategies. Clinical and basic research studies gradually led to improved outcomes in patients with brain tumors. Stupp et al. reported a mean survival of 14.6 months in glioblastoma multiforme (GBM) patients treated with radiotherapy plus temozolomide and 12.1 months in those subjected to radiotherapy alone. Earlier cancer therapies primarily targeted rapidly dividing cells but not minor populations of slowly dividing cells that contain BTSCs. Accumulating evidence suggests that BTSCs may represent an excellent tool for discovering new strategies to treat GBM patients. In this review, we present evidence supporting the CSC model of tumor progression, and discuss difficulties encountered in CSC research and experimental and therapeutic implications. (author)

  7. Optical spectroscopy for stereotactic biopsy of brain tumors

    Science.gov (United States)

    Markwardt, Niklas; von Berg, Anna; Fiedler, Sebastian; Goetz, Marcus; Haj-Hosseini, Neda; Polzer, Christoph; Stepp, Herbert; Zelenkov, Petr; Rühm, Adrian

    2015-07-01

    Stereotactic biopsy procedure is performed to obtain a tissue sample for diagnosis purposes. Currently, a fiber-based mechano-optical device for stereotactic biopsies of brain tumors is developed. Two different fluorophores are employed to improve the safety and reliability of this procedure: The fluorescence of intravenously applied indocyanine green (ICG) facilitates the recognition of blood vessels and thus helps minimize the risk of cerebral hemorrhages. 5- aminolevulinic-acid-induced protoporphyrin IX (PpIX) fluorescence is used to localize vital tumor tissue. ICG fluorescence detection using a 2-fiber probe turned out to be an applicable method to recognize blood vessels about 1.5 mm ahead of the fiber tip during a brain tumor biopsy. Moreover, the suitability of two different PpIX excitation wavelengths regarding practical aspects was investigated: While PpIX excitation in the violet region (at 405 nm) allows for higher sensitivity, red excitation (at 633 nm) is noticeably superior with regard to blood layers obscuring the fluorescence signal. Contact measurements on brain simulating agar phantoms demonstrated that a typical blood coverage of the tumor reduces the PpIX signal to about 75% and nearly 0% for 633 nm and 405 nm excitation, respectively. As a result, 633 nm seems to be the wavelength of choice for PpIX-assisted detection of high-grade gliomas in stereotactic biopsy.

  8. Glutamate Pays Its Own Way in Astrocytes

    OpenAIRE

    MaryC.McKenna

    2013-01-01

    In vitro and in vivo studies have shown that glutamate can be oxidized for energy by brain astrocytes. The ability to harvest the energy from glutamate provides astrocytes with a mechanism to offset the high ATP cost of the uptake of glutamate from the synaptic cleft. This brief review focuses on oxidative metabolism of glutamate by astrocytes, the specific pathways involved in the complete oxidation of glutamate and the energy provided by each reaction.

  9. Peptide gH625 enters into neuron and astrocyte cell lines and crosses the blood–brain barrier in rats

    Directory of Open Access Journals (Sweden)

    Valiante S

    2015-03-01

    Full Text Available Salvatore Valiante,1,* Annarita Falanga,2,3,* Luisa Cigliano,1 Giuseppina Iachetta,1 Rosa Anna Busiello,1 Valeria La Marca,1 Massimiliano Galdiero,4 Assunta Lombardi,1 Stefania Galdiero1,2 1Department of Biology, 2Department of Pharmacy, 3DFM Scarl, University of Naples Federico II, 4Department of Experimental Medicine, II University of Naples, Naples, Italy *These authors contributed equally to this paper and are considered joint first authors Abstract: Peptide gH625, derived from glycoprotein H of herpes simplex virus type 1, can enter cells efficiently and deliver a cargo. Nanoparticles armed with gH625 are able to cross an in vitro model of the blood–brain barrier (BBB. In the present study, in vitro experiments were performed to investigate whether gH625 can enter and accumulate in neuron and astrocyte cell lines. The ability of gH625 to cross the BBB in vivo was also evaluated. gH625 was administered in vivo to rats and its presence in the liver and in the brain was detected. Within 3.5 hours of intravenous administration, gH625 can be found beyond the BBB in proximity to cell neurites. gH625 has no toxic effects in vivo, since it does not affect the maximal oxidative capacity of the brain or the mitochondrial respiration rate. Our data suggest that gH625, with its ability to cross the BBB, represents a novel nanocarrier system for drug delivery to the central nervous system. These results open up new possibilities for direct delivery of drugs into patients in the field of theranostics and might address the treatment of several human diseases. Keywords: drug delivery, neurons, astrocytes, blood–brain barrier, peptide

  10. Technological progress in radiation therapy for brain tumors

    LENUS (Irish Health Repository)

    Vernimmen, Frederik Jozef

    2014-01-01

    To achieve a good therapeutic ratio the radiation dose to the tumor should be as high as possible with the lowest possible dose to the surrounding normal tissue. This is especially the case for brain tumors. Technological ad- vancements in diagnostic imaging, dose calculations, and radiation delivery systems, combined with a better un- derstanding of the pathophysiology of brain tumors have led to improvements in the therapeutic results. The widely used technology of delivering 3-D conformal therapy with photon beams (gamma rays) produced by Li-near Accelerators has progressed into the use of Intensity modulated radiation therapy (IMRT). Particle beams have been used for several decades for radiotherapy because of their favorable depth dose characteristics. The introduction of clinically dedicated proton beam therapy facilities has improved the access for cancer patients to this treatment. Proton therapy is of particular interest for pediatric malignancies. These technical improvements are further enhanced by the evolution in tumor physiology imaging which allows for improved delineation of the tumor. This in turn opens the potential to adjust the radiation dose to maximize the radiobiological effects. The advances in both imaging and radiation therapy delivery will be discussed.

  11. Dysembryoplastic neuroepithelial tumor: A rare brain tumor not to be misdiagnosed.

    Science.gov (United States)

    Sukheeja, Deepti; Mehta, Jayanti

    2016-01-01

    Dysembryoplastic neuroepithelial tumor (DNET) is a recently described, morphologically unique, and surgically curable low-grade brain tumor which is included in the latest WHO classification as neuronal and mixed neuronal-glial tumor. It is usually seen in children and young adults. The importance of this particular entity is that it is a surgically curable neuroepithelial neoplasm. When recognized, the need for adjuvant radiotherapy and chemotherapy is obviated. We hereby present a case report of an 8-year-old male child who presented with intractable seizures and parieto-occipital space occupying lesion. Histologically, the tumor exhibited features of WHO grade I dysembryoplastic neuroepithelial tumor which was further confirmed by immunohistochemistry. PMID:27057233

  12. New Experimental Model of Brain Tumors in Brains of Adult Immunocompetent Rats

    OpenAIRE

    Baklaushev, Vladimir P.; Kavsan, Vadym M.; Balynska, Olena V; Yusubalieva, Gaukhar M.; Abakumov, Maxim A.; Chekhonin, Vladimir P.

    2012-01-01

    Aims: Xenograft models, namely heterotransplantation of human cancer cells or tumor biopsies into immunodeficient rodents are the major preclinical approach for the development of novel cancer therapeutics. However, in these models the animals must be used only after the severe systemic immune suppression in order to ensure graft survival. Thus, additional new human brain tumor models without immune suppression of the recipient rodent may be required. Place and Duration of Study: Laboratory o...

  13. Collecting and Storing Blood and Brain Tumor Tissue Samples From Children With Brain Tumors

    Science.gov (United States)

    2016-05-17

    Childhood Atypical Teratoid/Rhabdoid Tumor; Childhood Central Nervous System Germ Cell Tumor; Childhood Choroid Plexus Tumor; Childhood Craniopharyngioma; Childhood Grade I Meningioma; Childhood Grade II Meningioma; Childhood Grade III Meningioma; Childhood High-grade Cerebral Astrocytoma; Childhood Infratentorial Ependymoma; Childhood Low-grade Cerebral Astrocytoma; Childhood Oligodendroglioma; Childhood Supratentorial Ependymoma; Newly Diagnosed Childhood Ependymoma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma; Recurrent Childhood Visual Pathway Glioma

  14. Efficient multilevel brain tumor segmentation with integrated bayesian model classification.

    Science.gov (United States)

    Corso, J J; Sharon, E; Dube, S; El-Saden, S; Sinha, U; Yuille, A

    2008-05-01

    We present a new method for automatic segmentation of heterogeneous image data that takes a step toward bridging the gap between bottom-up affinity-based segmentation methods and top-down generative model based approaches. The main contribution of the paper is a Bayesian formulation for incorporating soft model assignments into the calculation of affinities, which are conventionally model free. We integrate the resulting model-aware affinities into the multilevel segmentation by weighted aggregation algorithm, and apply the technique to the task of detecting and segmenting brain tumor and edema in multichannel magnetic resonance (MR) volumes. The computationally efficient method runs orders of magnitude faster than current state-of-the-art techniques giving comparable or improved results. Our quantitative results indicate the benefit of incorporating model-aware affinities into the segmentation process for the difficult case of glioblastoma multiforme brain tumor. PMID:18450536

  15. Specific features of epilepsy in children with brain tumors

    Directory of Open Access Journals (Sweden)

    G. V. Kalmykova

    2015-03-01

    Full Text Available Objective: to study the specific features of epilepsy in children and adolescents with brain tumors and to define the optimal tactics of management and antiepileptic therapy after surgical treatment. Patients and methods. Sixty-one patients aged 5 months to 15 years were examined. All the patients were diagnosed as having a brain tumor found in the presence of symptomatic epilepsy. They were all followed up for 5 years postsurgery or during their lifetime (in case of death. Comprehensive examination encompassing the assessment of history data and concomitant complaints, brain magnetic resonance imaging, video-EEC monitoring, and the neurological status (the presence of cognitive impairments and eye ground changes was done in all the cases. The probability of epileptic seizures in the clinical presentation of the disease, their semiology, and frequency were studied. Results and discussion. Epileptic seizures were the major complaint in all the patients at the first visit to their doctor. The disease occurred with status epilepticus in 9% of the patients. Different types of generalized seizures were more common (53%; p≥0.05. The tumor was located above the tentorium of the cerebellum in most examinees (77% and beneath it in the others (23%; p≤0.05. The significant clinical sign of a brain tumor in the epileptic children is focal neurological symptoms (72% of the cases. MRI was performed in children who had no focal neurological symptoms in the late periods. There was cerebrospinal fluid hypertension in 51% of the patients (p≥0.05 and cognitive impairments in 33% (p<0.05. The maximum number (74% of children with psycho-speech disorders and cognitive impairments were registered in the age group of 7–15 years. Eye ground changes characteristic of intracranial hypertension were identified in 19 epileptic children; they occurred in 27 patients more than 1 year after the onset of seizures. The late (few months-to-14 years diagnosis of a brain

  16. Recent molecular approaches to understanding astrocyte function in vivo

    Directory of Open Access Journals (Sweden)

    Todd A Fiacco

    2013-12-01

    Full Text Available Astrocytes are a predominant glial cell type in the nervous systems, and are becoming recognized as important mediators of normal brain function as well as neurodevelopmental, neurological, and neurodegenerative brain diseases. Although numerous potential mechanisms have been proposed to explain the role of astrocytes in the normal and diseased brain, research into the physiological relevance of these mechanisms in vivo is just beginning. In this review, we will summarize recent developments in innovative and powerful molecular approaches, including knockout mouse models, transgenic mouse models, and astrocyte-targeted gene transfer/expression, which have led to advances in understanding astrocyte biology in vivo that were heretofore inaccessible to experimentation. We will examine the recently improved understanding of the roles of astrocytes - with an emphasis on astrocyte signaling - in the context of both the healthy and diseased brain, discuss areas where the role of astrocytes remains debated, and suggest new research directions.

  17. Excitotoxic brain damage in the rat induces interleukin-1beta protein in microglia and astrocytes: correlation with the progression of cell death.

    Science.gov (United States)

    Pearson, V L; Rothwell, N J; Toulmond, S

    1999-02-15

    Interleukin-1 beta (IL-1beta) has been proposed as a mediator of several forms of brain damage, including that induced by excitotoxins. In vitro studies suggest that glial cells are the effector cells of IL-1beta-mediated neurodegeneration. We have investigated the expression of IL-1beta protein by glial cells in vivo in response to NMDA receptor-mediated excitotoxicity in the rat parietal cortex and striatum. Expression of IL-1beta by glial cells was investigated using immunocytochemistry 30 min to 7 days after infusion of the NMDA agonist cis-2,4-methanoglutamate (MGlu; 10 nmol) into the cortex. Early expression (1-4 h) of IL-1beta by microglia was directly related to lesion development. Later expression by microglia (up to 24 h), and by astrocytes (2-7 days), was widespread compared to the area involved in excitotoxic cell death and co-localised with areas of reactive gliosis. Infusion of MGlu into the striatum induced a similar temporal pattern of IL-1beta expression by microglia and astrocytes. However, IL-1beta-expressing glial cells were localised strictly to the area of striatal cell death. Infusion of PBS or a subtoxic dose of MGlu into the cortex or striatum induced only limited neuronal death and negligible glial IL-1beta expression. These studies reveal that IL-1beta is expressed specifically by microglia during the early response to excitotoxicity in the adult rat cortex and striatum. However, the widespread and delayed IL-1beta expression by astrocytes suggests diverse roles for IL-1beta in response to excitotoxicity. PMID:10028914

  18. Using Diffusion-weighted Images to Identify Brain Tumors

    Czech Academy of Sciences Publication Activity Database

    Marcon, P.; Bartušek, Karel; Šprláková, A.

    Cambridge: The Electromagnetics Academy, 2014, s. 2340-2343. ISBN 978-1-934142-28-8. [PIERS 2014. Progress In Electromagnetics Research Symposium /35./. Guangzhou (CN), 25.08.2014-28.08.2014] R&D Projects: GA ČR GAP102/12/1104 Institutional support: RVO:68081731 Keywords : brain tumor * MRI * diffusion-weighted image s Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  19. Pediatric brain stem tumors: analysis of 25 cases

    International Nuclear Information System (INIS)

    The charts of 25 pediatric patients with brain stem tumors have been reviewed. The use of computed tomography was found to have been valuable in diagnosis and follow-up, as well as in the design of radiation therapy portals. Radiotherapy and combination chemotherapy with VM-26 (4'-1 demethyl-epipodophyllo toxin B-D-thenylidene glucoside) and CCNU(1-2-chloroethyl-methyl-3-Cyclohexyl-1-nitrosourea) were the treatment employed. (M.A.C.)

  20. Amitriptyline induces brain-derived neurotrophic factor (BDNF) mRNA expression through ERK-dependent modulation of multiple BDNF mRNA variants in primary cultured rat cortical astrocytes and microglia.

    Science.gov (United States)

    Hisaoka-Nakashima, Kazue; Kajitani, Naoto; Kaneko, Masahiro; Shigetou, Takahiro; Kasai, Miho; Matsumoto, Chie; Yokoe, Toshiki; Azuma, Honami; Takebayashi, Minoru; Morioka, Norimitsu; Nakata, Yoshihiro

    2016-03-01

    A significant role of brain-derived neurotrophic factor (BDNF) has been previously implicated in the therapeutic effect of antidepressants. To ascertain the contribution of specific cell types in the brain that produce BDNF following antidepressant treatment, the effects of the tricyclic antidepressant amitriptyline on rat primary neuronal, astrocytic and microglial cortical cultures were examined. Amitriptyline increased the expression of BDNF mRNA in astrocytic and microglial cultures but not neuronal cultures. Antidepressants with distinct mechanisms of action, such as clomipramine, duloxetine and fluvoxamine, also increased BDNF mRNA expression in astrocytic and microglial cultures. There are multiple BDNF mRNA variants (exon I, IIA, IV and VI) expressed in astrocytes and microglia and the variant induced by antidepressants has yet to be elaborated. Treatment with antidepressants increased the expression of exon I, IV and VI in astrocyte and microglia. Clomipramine alone significantly upregulated expression of exon IIA. The amitriptyline-induced expression of both total and individual BDNF mRNA variants (exon I, IV and VI) were blocked by MEK inhibitor U0126, indicating MEK/ERK signaling is required in the expression of BDNF. These findings indicate that non-neural cells are a significant target of antidepressants and further support the contention that glial production of BDNF is crucial role in the therapeutic effect of antidepressants. The current data suggest that targeting of glial function could lead to the development of antidepressants with a truly novel mechanism of action. PMID:26764533

  1. CD133 is not present on neurogenic astrocytes in the adult subventricular zone, but on embryonic neural stem cells, ependymal cells, and glioblastoma cells.

    Science.gov (United States)

    Pfenninger, Cosima V; Roschupkina, Teona; Hertwig, Falk; Kottwitz, Denise; Englund, Elisabet; Bengzon, Johan; Jacobsen, Sten Eirik; Nuber, Ulrike A

    2007-06-15

    Human brain tumor stem cells have been enriched using antibodies against the surface protein CD133. An antibody recognizing CD133 also served to isolate normal neural stem cells from fetal human brain, suggesting a possible lineage relationship between normal neural and brain tumor stem cells. Whether CD133-positive brain tumor stem cells can be derived from CD133-positive neural stem or progenitor cells still requires direct experimental evidence, and an important step toward such investigations is the identification and characterization of normal CD133-presenting cells in neurogenic regions of the embryonic and adult brain. Here, we present evidence that CD133 is a marker for embryonic neural stem cells, an intermediate radial glial/ependymal cell type in the early postnatal stage, and for ependymal cells in the adult brain, but not for neurogenic astrocytes in the adult subventricular zone. Our findings suggest two principal possibilities for the origin of brain tumor stem cells: a derivation from CD133-expressing cells, which are normally not present in the adult brain (embryonic neural stem cells and an early postnatal intermediate radial glial/ependymal cell type), or from CD133-positive ependymal cells in the adult brain, which are, however, generally regarded as postmitotic. Alternatively, brain tumor stem cells could be derived from proliferative but CD133-negative neurogenic astrocytes in the adult brain. In the latter case, brain tumor development would involve the production of CD133. PMID:17575139

  2. Epidemiology of brain tumors in childhood--a review

    International Nuclear Information System (INIS)

    Malignant brain tumors are the leading cause of cancer death among children and the second most common type of pediatric cancer. Despite several decades of epidemiologic investigation, the etiology of childhood brain tumors (CBT) is still largely unknown. A few genetic syndromes and ionizing radiation are established risk factors. Many environmental exposures and infectious agents have been suspected of playing a role in the development of CBT. This review, based on a search of the medical literature through August 2003, summarizes the epidemiologic evidence to date. The types of exposures discussed include ionizing radiation, N-nitroso compounds (NOC), pesticides, tobacco smoke, electromagnetic frequencies (EMF), infectious agents, medications, and parental occupational exposures. We have chosen to focus on perinatal exposures and review some of the recent evidence indicating that such exposures may play a significant role in the causation of CBT. The scientific community is rapidly learning more about the molecular mechanisms by which carcinogenesis occurs and how the brain develops. We believe that advances in genetic and molecular biologic technology, including improved histologic subtyping of tumors, will be of huge importance in the future of epidemiologic research and will lead to a more comprehensive understanding of CBT etiology. We discuss some of the early findings using these technologies

  3. Linear-accelerator-based stereotactic irradiation for metastatic brain tumors

    International Nuclear Information System (INIS)

    To assess the safety and availability of stereotactic radiotherapy (SRT) for metastatic brain tumors, we reviewed 54 consecutive cases with a total of 118 brain metastases treated with linear-accelerator-based stereotactic irradiation (STI). Nineteen patients with a total of 27 brain tumors that were larger than 3 cm or close to critical normal tissues were treated with SRT. The marginal dose of SRT was 15-21 Gy (median 21 Gy) in 3 fractions for 3 days. The median marginal dose of stereotactic radiosurgery (SRS) was 20 Gy. Effective rates of imaging studies were 72.7% and 94.4%, and those of clinical symptoms were 46.7% and 55.6% for SRT and SRS, respectively. One-year and two-year survival rates of SRT were 40.9% and 17.6%, respectively, and the median follow-up period was 6.4 months. The one-year survival rate of SRS was 32.7%, with a median follow-up of 4.6 months. Fourteen cases (7 cases each) had recurrent tumors at STI sites. Early complications were observed in one case of SRT and 8 cases of SRS, and late complications occurred in 3 cases of SRS. There were no significant differences among effective rates, survival rates, median follow-up times, recurrence rates, and complications between SRT and SRS. We concluded that SRT is a safe, effective therapy for large or eloquent area metastases. (author)

  4. Linear-accelerator-based stereotactic irradiation for metastatic brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Takemoto, Mitsuhiro; Katsui, Kuniaki; Yoshida, Atsushi [Okayama Univ. (Japan). School of Medicine] [and others

    2003-05-01

    To assess the safety and availability of stereotactic radiotherapy (SRT) for metastatic brain tumors, we reviewed 54 consecutive cases with a total of 118 brain metastases treated with linear-accelerator-based stereotactic irradiation (STI). Nineteen patients with a total of 27 brain tumors that were larger than 3 cm or close to critical normal tissues were treated with SRT. The marginal dose of SRT was 15-21 Gy (median 21 Gy) in 3 fractions for 3 days. The median marginal dose of stereotactic radiosurgery (SRS) was 20 Gy. Effective rates of imaging studies were 72.7% and 94.4%, and those of clinical symptoms were 46.7% and 55.6% for SRT and SRS, respectively. One-year and two-year survival rates of SRT were 40.9% and 17.6%, respectively, and the median follow-up period was 6.4 months. The one-year survival rate of SRS was 32.7%, with a median follow-up of 4.6 months. Fourteen cases (7 cases each) had recurrent tumors at STI sites. Early complications were observed in one case of SRT and 8 cases of SRS, and late complications occurred in 3 cases of SRS. There were no significant differences among effective rates, survival rates, median follow-up times, recurrence rates, and complications between SRT and SRS. We concluded that SRT is a safe, effective therapy for large or eloquent area metastases. (author)

  5. Heavy metals and epigenetic alterations in brain tumors.

    Science.gov (United States)

    Caffo, Maria; Caruso, Gerardo; Fata, Giuseppe La; Barresi, Valeria; Visalli, Maria; Venza, Mario; Venza, Isabella

    2014-12-01

    Heavy metals and their derivatives can cause various diseases. Numerous studies have evaluated the possible link between exposure to heavy metals and various cancers. Recent data show a correlation between heavy metals and aberration of genetic and epigenetic patterns. From a literature search we noticed few experimental and epidemiological studies that evaluate a possible correlation between heavy metals and brain tumors. Gliomas arise due to genetic and epigenetic alterations of glial cells. Changes in gene expression result in the alteration of the cellular division process. Epigenetic alterations in brain tumors include the hypermethylation of CpG group, hypomethylation of specific genes, aberrant activation of genes, and changes in the position of various histones. Heavy metals are capable of generating reactive oxygen assumes that key functions in various pathological mechanisms. Alteration of homeostasis of metals could cause the overproduction of reactive oxygen species and induce DNA damage, lipid peroxidation, and alteration of proteins. In this study we summarize the possible correlation between heavy metals, epigenetic alterations and brain tumors. We report, moreover, the review of relevant literature. PMID:25646073

  6. Holmium-166-chico intracavitary radiation therapy for cystic brain tumors

    International Nuclear Information System (INIS)

    Holmium-166-chitosan complex (Ho-166-chico) is injected into the unresectable seven cystic brain tumors (2 cases of metastatic brain tumors from lung cancer, 1 case of recurrent trigeminal neurinoma, 3 cases of recurrent low grade cystic astrocytomas, and 1 case of craniopharyngioma). The Ommaya reservoir was installed stereotactically. The cyst volume and wall thickness were measured by MRI before Ho-166-chico injection. The thickness of the cyst wall is up to 4 mm. Ho-166-chico (555-740 MBq) injected into the cyst to result in 25 Gy of dose to a cyst wall at a depth of 4 mm. Dose to the cyst wall was estimated by Monte Carlo simulation using the EGS4 code. All Ho-166-chico injected was assumed to be uniformly distributed in the spherical cyst. After Ho-166-chico injection, the distribution of isotopes was monitored by gamma camera. Two injections were administrated in two cases, and one injection in all the others. The response was evaluated with MRI. Four of 7 cases were shrunk in size with thinning of the cyst wall, 2 of 7 cases showed growth arrest, and one case showed progression. Estimated surface dose of cyst wall was between 78 and 2566 Gy. No one showed systemic absorption of Ho-166-chico, and specific complication associated with isotope injection. Ho-166-chico intracavitary radiation therapy for cystic brain tumor may be safe, and reliable method and deserves further evaluation

  7. Label-free optical activation of astrocyte in vivo

    Science.gov (United States)

    Choi, Myunghwan; Yoon, Jonghee; Ku, Taeyun; Choi, Kyungsun; Choi, Chulhee

    2011-07-01

    As the most abundant cell type in the central nervous system, astrocyte has been one of main research topics in neuroscience. Although various tools have been developed, at present, there is no tool that allows noninvasive activation of astrocyte in vivo without genetic or pharmacological perturbation. Here we report a noninvasive label-free optical method for physiological astrocyte activation in vivo using a femtosecond pulsed laser. We showed the laser stimulation robustly induced astrocytic calcium activation in vivo and further verified physiological relevance of the calcium increase by demonstrating astrocyte mediated vasodilation in the brain. This novel optical method will facilitate noninvasive physiological study on astrocyte function.

  8. Astrocytes and Developmental White Matter Disorders

    Science.gov (United States)

    Sen, Ellora; Levison, Steven W.

    2006-01-01

    There is an increasing awareness that the astrocytes in the immature periventricular white matter are vulnerable to ischemia and respond to inflammation. Here we provide a synopsis of the articles that have evaluated the causes and consequences of developmental brain injuries to white matter astrocytes as well as the consequences of several…

  9. Organization of Endothelial Cells, Pericytes, and Astrocytes into a 3D Microfluidic in Vitro Model of the Blood-Brain Barrier.

    Science.gov (United States)

    Wang, Jack D; Khafagy, El-Sayed; Khanafer, Khalil; Takayama, Shuichi; ElSayed, Mohamed E H

    2016-03-01

    The endothelial cells lining the capillaries supplying the brain with oxygen and nutrients form a formidable barrier known as the blood-brain barrier (BBB), which exhibits selective permeability to small drug molecules and virtually impermeable to macromolecular therapeutics. Current in vitro BBB models fail to replicate this restrictive behavior due to poor integration of the endothelial cells with supporting cells (pericytes and astrocytes) following the correct anatomical organization observed in vivo. We report the coculture of mouse brain microvascular endothelial cells (b.End3), pericytes, with/without C8-D1A astrocytes in layered microfluidic channels forming three-dimensional (3D) bi- and triculture models of the BBB. The live/dead assay indicated high viability of all cultured cells up to 21 days. Trans-endothelial electrical resistance (TEER) values confirmed the formation of intact monolayers after 3 days in culture and showed statistically higher values for the triculture model compared to the single and biculture models. Screening the permeability of [(14)C]-mannitol and [(14)C]-urea showed the ability of bi- and triculture models to discriminate between different markers based on their size. Further, permeability of [(14)C]-mannitol across the triculture model after 18 days in culture matched its reported permeability across the BBB in vivo. Mathematical calculations also showed that the radius of the tight junctions pores (R) in the triculture model is similar to the reported diameter of the BBB in vivo. Finally, both the bi- and triculture models exhibited functional expression of the P-glycoprotein efflux pump, which increased with the increase in the number of days in culture. These results collectively indicate that the triculture model is a robust in vitro model of the BBB. PMID:26751280

  10. Brain Tumor Detection Based on Bilateral Symmetry Information

    Directory of Open Access Journals (Sweden)

    Narkhede Sachin,

    2014-06-01

    Full Text Available Advances in computing technology have allowed researchers across many fields of endeavor to collect and maintain vast amounts of observational statistical data such as clinical data, biological patient data, data regarding access of web sites , financial data, and the like. Brain Magnetic Resonance Imaging (MRI segmentation is a complex problem in the field of medical imaging despite various presented methods. MR image of human brain can be divided into several sub-regions especially soft tissues such as gray matter, white matter and cerebrospinal fluid. Although edge information is the main clue in image segmentation, it can’t get a better result in analysis the content of images without combining other information. The segmentation of brain tissue in the magnetic resonance imaging (MRI is very important for detecting the existence and outlines of tumors. In this thesis , an algorithm about segmentation based on the symmetry character of brain MRI image is presented. Our goal is to detect the position and boundary of tumors automatically. Experiments were conducted on real pictures, and the results show that the algorithm is flexible and convenient.

  11. mTHPC-mediated photodynamic diagnosis of malignant brain tumors

    International Nuclear Information System (INIS)

    Radical tumor resection is the basis for prolonged survival of patients suffering from malignant brain tumors such as glioblastoma multiform. We have carried out a phase II study involving 22 patients with malignant brain tumors to assess the feasibility and the effectiveness of the combination of intraoperative photodynamic diagnosis (PDD) and fluorescence-guided resection (FGR) mediated by the second generation photosensitizer meta-tetrahydroxyphenylchlorin (mTHPC). In addition, intraoperative photodynamic therapy (PDT) was performed. Several commercially available fluorescence diagnostic systems were investigated for their applicability for clinical practice. We have adapted and optimized a diagnostic system which includes a surgical microscope, an excitation light source (filtered to 370-440 nm), a video camera detection system, and a spectrometer for clear identification of the mTHPC fluorescence emission at 652 nm. Especially in regions of faint fluorescence it turned out to be essential to maximize the spectral information by optimizing and matching the spectral properties of all components, such as excitation source, camera and color filters. In summary, based on 138 tissue samples derived from 22 tumor specimens we have been able to achieve a sensitivity of 87.9 % and a specificity of 95.7 %. This study demonstrates that mTHPC-mediated intraoperative fluorescence-guided resection followed by photodynamic therapy is a feasible concept. (author)

  12. Changes in liver mitochondrial plasticity induced by brain tumor

    International Nuclear Information System (INIS)

    Accumulating data suggest that liver is a major target organ of systemic effects observed in the presence of a cancer. In this study, we investigated the consequences of the presence of chemically induced brain tumors in rats on biophysical parameters accounting for the dynamics of water in liver mitochondria. Tumors of the central nervous system were induced by intraveinous administration of ethylnitrosourea (ENU) to pregnant females on the 19th day of gestation. The mitochondrial crude fraction was isolated from the liver of each animal and the dynamic parameters of total water and its macromolecule-associated fraction (structured water, H2Ost) were calculated from Nuclear Magnetic Resonance (NMR) measurements. The presence of a malignant brain tumor induced a loss of water structural order that implicated changes in the physical properties of the hydration shells of liver mitochondria macromolecules. This feature was linked to an increase in the membrane cholesterol content, a way to limit water penetration into the bilayer and then to reduce membrane permeability. As expected, these alterations in mitochondrial plasticity affected ionic exchanges and led to abnormal features of mitochondrial biogenesis and caspase activation. This study enlightens the sensitivity of the structured water phase in the liver mitochondria machinery to external conditions such as tumor development at a distant site. The profound metabolic and functional changes led to abnormal features of ion transport, mitochondrial biogenesis and caspase activation

  13. Peritumoral hemorrhage immediately after radiosurgery for metastatic brain tumor

    International Nuclear Information System (INIS)

    We report a case of a 44-year-old woman with metastatic brain tumors who suffered peri-tumoral hemorrhage soon after stereotactic radiosurgery (SRS). She had been suffering from breast cancer with multiple systemic metastasis. She started to have headache, nausea, dizziness and speech disturbance 1 month before admission. There was no bleeding tendency in the hematological examination and the patient was normotensive. Neurological examination disclosed headache and slightly aphasia. Magnetic resonance imaging showed a large round mass lesion in the left temporal lobe. It was a well-demarcated, highly enhanced mass, 45 mm in diameter. SRS was performed on four lesions in a single session (Main mass: maximum dose was 30 Gy in the center and 20 Gy in the margin of the tumor. Others: maximum 25 Gy margin 20 Gy). After radiosurgery, she had severe headache, nausea and vomiting and showed progression of aphasia. CT scan revealed a peritumoral hemorrhage. Conservative therapy was undertaken and the patient's symptoms improved. After 7 days, she was discharged, able to walk. The patient died of extensive distant metastasis 5 months after SRS. Acute transient swelling following conventional radiotherapy is a well-documented phenomenon. However, the present case indicates that such an occurrence is also possible in SRS. We have hypothesized that acute reactions such as brain swelling occur due to breakdown of the fragile vessels of the tumor or surrounding tissue. (author)

  14. Changes in liver mitochondrial plasticity induced by brain tumor

    Directory of Open Access Journals (Sweden)

    Debien Emilie

    2006-10-01

    Full Text Available Abstract Background Accumulating data suggest that liver is a major target organ of systemic effects observed in the presence of a cancer. In this study, we investigated the consequences of the presence of chemically induced brain tumors in rats on biophysical parameters accounting for the dynamics of water in liver mitochondria. Methods Tumors of the central nervous system were induced by intraveinous administration of ethylnitrosourea (ENU to pregnant females on the 19th day of gestation. The mitochondrial crude fraction was isolated from the liver of each animal and the dynamic parameters of total water and its macromolecule-associated fraction (structured water, H2Ost were calculated from Nuclear Magnetic Resonance (NMR measurements. Results The presence of a malignant brain tumor induced a loss of water structural order that implicated changes in the physical properties of the hydration shells of liver mitochondria macromolecules. This feature was linked to an increase in the membrane cholesterol content, a way to limit water penetration into the bilayer and then to reduce membrane permeability. As expected, these alterations in mitochondrial plasticity affected ionic exchanges and led to abnormal features of mitochondrial biogenesis and caspase activation. Conclusion This study enlightens the sensitivity of the structured water phase in the liver mitochondria machinery to external conditions such as tumor development at a distant site. The profound metabolic and functional changes led to abnormal features of ion transport, mitochondrial biogenesis and caspase activation.

  15. Astrocyte morphology during hypoosmotic stress and ischemia revealed by real-time 3D morphometry in brain slices in situ

    Czech Academy of Sciences Publication Activity Database

    Chvátal, Alexandr; Anděrová, Miroslava; Neprašová, Helena; Hock, Miroslav; Prajerová, Iva; Chvátal, V.; Syková, Eva

    Washington, DC : Society for Neuroscience, 2005. ---. [Neuroscience 2005, Annual Meeting /35./. 12.11.2005-16.11.2005, Washington, DC] R&D Projects: GA ČR(CZ) GA305/03/1172; GA ČR(CZ) GA305/04/1293; GA MŠk(CZ) 1M0538 Institutional research plan: CEZ:AV0Z50390512 Keywords : astrocyte morphology * extracellular space Subject RIV: FH - Neurology

  16. Multiclass imbalance learning:Improving classification of pediatric brain tumors from magnetic resonance spectroscopy

    OpenAIRE

    Zarinabad, Niloufar; Wilson, Martin P; Gill, Simrandip K.; Manias, Karen A; Davies, Nigel P; Peet, Andrew C

    2016-01-01

    PURPOSE: Classification of pediatric brain tumors from (1) H-magnetic resonance spectroscopy (MRS) can aid diagnosis and management of brain tumors. However, varied incidence of the different tumor types leads to imbalanced class sizes and introduces difficulties in classifying rare tumor groups. This study assessed different imbalanced multiclass learning techniques and compared the use of complete spectra and quantified metabolite profiles for classification of three main childhood brain tu...

  17. Transcriptomic analyses of primary astrocytes under TNFα treatment

    OpenAIRE

    Birck, Cindy; Koncina, Eric; Heurtaux, Tony; Glaab, Enrico; Michelucci, Alessandro; Heuschling, Paul; Grandbarbe, Luc

    2016-01-01

    Astrocytes, the most abundant glial cell population in the central nervous system, have important functional roles in the brain as blood brain barrier maintenance, synaptic transmission or intercellular communications [1], [2]. Numerous studies suggested that astrocytes exhibit a functional and morphological high degree of plasticity. For example, following any brain injury, astrocytes become reactive and hypertrophic. This phenomenon, also called reactive gliosis, is characterized by a set o...

  18. Thermal dosimetry studies of ultrasonically induced hyperthermia in normal dog brain and in experimental brain tumors

    International Nuclear Information System (INIS)

    In a series of 16 acute experiments on pentobarbital anesthetized dogs, thermal distributions generated by ultrasonic heating using a 1 MHz PZT transducer were compared with intensity distributions mapped in a test tank. Relatively flat distributions from 1 to 3 cm have been mapped in normal dog brain using ''shaped'' intensity distributions generated from ultrasonic emission patterns which are formed by the interaction between compressional, transverse and flexural modes activated within the crystal. In contrast, these same intensity distributions generated marked temperature variations in 3 malignant brain tumors presumably due to variations in tumor blood flow. The results of this study suggest that a practical clinical system for uniform heating of large tumor volumes with varying volumes and geometries is not an achievable goal. The author's laboratory is developing a scanning ultrasonic rapid hyperthermia treatment system which will be able to sequentially heat small volume of tumor tissue either to temperatures which will sterilize tumor or to a more conventional thermal dose. Time-temperature studies of threshold for thermal damage in normal dog brain are currently in progress

  19. Astrocyte Regulation of CNS Inflammation and Remyelination

    Directory of Open Access Journals (Sweden)

    Stephen J. Crocker

    2013-07-01

    Full Text Available Astrocytes regulate fundamentally important functions to maintain central nervous system (CNS homeostasis. Altered astrocytic function is now recognized as a primary contributing factor to an increasing number of neurological diseases. In this review, we provide an overview of our rapidly developing understanding of the basal and inflammatory functions of astrocytes as mediators of CNS responsiveness to inflammation and injury. Specifically, we elaborate on ways that astrocytes actively participate in the pathogenesis of demyelinating diseases of the CNS through their immunomodulatory roles as CNS antigen presenting cells, modulators of blood brain barrier function and as a source of chemokines and cytokines. We also outline how changes in the extracellular matrix can modulate astrocytes phenotypically, resulting in dysregulation of astrocytic responses during inflammatory injury. We also relate recent studies describing newly identified roles for astrocytes in leukodystrophies. Finally, we describe recent advances in how adapting this increasing breadth of knowledge on astrocytes has fostered new ways of thinking about human diseases, which offer potential to modulate astrocytic heterogeneity and plasticity towards therapeutic gain. In summary, recent studies have provided improved insight in a wide variety of neuroinflammatory and demyelinating diseases, and future research on astrocyte pathophysiology is expected to provide new perspectives on these diseases, for which new treatment modalities are increasingly necessary.

  20. Involvement of astrocytes in neurovascular communication.

    Science.gov (United States)

    Nuriya, M; Hirase, H

    2016-01-01

    The vascular interface of the brain is distinct from that of the peripheral tissue in that astrocytes, the most numerous glial cell type in the gray matter, cover the vasculature with their endfeet. This morphological feature of the gliovascular junction has prompted neuroscientists to suggest possible functional roles of astrocytes including astrocytic modulation of the vasculature. Additionally, astrocytes develop an intricate morphology that intimately apposes neuronal synapses, making them an ideal cellular mediator of neurovascular coupling. In this article, we first introduce the classical anatomical and physiological findings that led to the proposal of various gliovascular interaction models. Next, we touch on the technological advances in the past few decades that enabled investigations and evaluations of neuro-glio-vascular interactions in situ. We then review recent experimental findings on the roles of astrocytes in neurovascular coupling from the viewpoints of intra- and intercellular signalings in astrocytes. PMID:27130410

  1. Astrocyte calcium signaling: the third wave.

    Science.gov (United States)

    Bazargani, Narges; Attwell, David

    2016-01-27

    The discovery that transient elevations of calcium concentration occur in astrocytes, and release 'gliotransmitters' which act on neurons and vascular smooth muscle, led to the idea that astrocytes are powerful regulators of neuronal spiking, synaptic plasticity and brain blood flow. These findings were challenged by a second wave of reports that astrocyte calcium transients did not mediate functions attributed to gliotransmitters and were too slow to generate blood flow increases. Remarkably, the tide has now turned again: the most important calcium transients occur in fine astrocyte processes not resolved in earlier studies, and new mechanisms have been discovered by which astrocyte [Ca(2+)]i is raised and exerts its effects. Here we review how this third wave of discoveries has changed our understanding of astrocyte calcium signaling and its consequences for neuronal function. PMID:26814587

  2. Dynamic reactive astrocytes after focal ischemia

    Institute of Scientific and Technical Information of China (English)

    Shinghua Ding

    2014-01-01

    Astrocytes are specialized and most numerous glial cell type in the central nervous system and play important roles in physiology. Astrocytes are also critically involved in many neural disor-ders including focal ischemic stroke, a leading cause of brain injury and human death. One of the prominent pathological features of focal ischemic stroke is reactive astrogliosis and glial scar for-mation associated with morphological changes and proliferation. This review paper discusses the recent advances in spatial and temporal dynamics of morphology and proliferation of reactive astrocytes after ischemic stroke based on results from experimental animal studies. As reactive astrocytes exhibit stem cell-like properties, knowledge of dynamics of reactive astrocytes and glial scar formation will provide important insights for astrocyte-based cell therapy in stroke.

  3. Triptolide protects astrocytes from hypoxia/ reoxygenation injury

    Institute of Scientific and Technical Information of China (English)

    Minfang Guo; Hongcui Fan; Jiezhong Yu; Ning Ji; Yongsheng Sun; Liyun Liang; Baoguo Xiao; Cungen Ma

    2011-01-01

    Astrocytes in an in vitro murine astrocyte model of oxygen and glucose deprivation/hypoxia and reoxygenation were treated with different concentrations of triptolide (250, 500, 1 000 ng/mL) in a broader attempt to elucidate the protection and mechanism underlying triptolide treatment on astrocytes exposed to hypoxia/reoxygenation injury. The results showed that the matrix metalloproteinase-9, interleukin-1β, tumor necrosis factor α and interleukin-6 expressions were significantly decreased after triptolide treatment in the astrocytes exposed to hypoxia/ reoxygenation injury, while interleukin-10 expression was upregulated. In addition, the vitality of the injured astrocytes was enhanced, the triptolide's effect was apparent at 500 ng/mL. These experimental findings indicate that triptolide treatment could protect astrocytes against hypoxia/ reoxygenation injury through the inhibition of inflammatory response and the reduction of matrix metalloproteinase-9 expression.

  4. The fibrinolytic system facilitates tumor cell migration across the blood-brain barrier in experimental melanoma brain metastasis

    International Nuclear Information System (INIS)

    Patients with metastatic tumors to the brain have a very poor prognosis. Increased metastatic potential has been associated with the fibrinolytic system. We investigated the role of the fibrinolytic enzyme plasmin in tumor cell migration across brain endothelial cells and growth of brain metastases in an experimental metastatic melanoma model. Metastatic tumors to the brain were established by direct injection into the striatum or by intracarotid injection of B16F10 mouse melanoma cells in C57Bl mice. The role of plasminogen in the ability of human melanoma cells to cross a human blood-brain barrier model was studied on a transwell system. Wild type mice treated with the plasmin inhibitor epsilon-aminocaproic acid (EACA) and plg-/- mice developed smaller tumors and survived longer than untreated wild type mice. Tumors metastasized to the brain of wild type mice treated with EACA and plg-/- less efficiently than in untreated wild type mice. No difference was observed in the tumor growth in any of the three groups of mice. Human melanoma cells were able to cross the human blood-brain barrier model in a plasmin dependent manner. Plasmin facilitates the development of tumor metastasis to the brain. Inhibition of the fibrinolytic system could be considered as means to prevent tumor metastasis to the brain

  5. Fetal dose estimates for radiotherapy of brain tumors during pregnancy

    International Nuclear Information System (INIS)

    Purpose: To determine clinically the fetal dose from irradiation of brain tumors during pregnancy and to quantitate the components of fetal dose using phantom measurements. Methods and Materials: Two patients received radiotherapy during pregnancy for malignant brain tumors. Case 1 was treated with opposed lateral blocked 10 x 15 cm fields and case 2 with 6 x 6 cm bicoronal wedged arcs, using 6 MV photons. Fetal dose was measured clinically and confirmed with phantom measurements using thermoluminescent dosimeters (TLDs). Further phantom measurements quantitated the components of scattered dose. Results: For case 1, both clinical and phantom measurements estimated fetal dose to be 0.09% of the tumor dose, corresponding to a total fetal dose of 0.06 Gy for a tumor dose of 68.0 Gy. Phantom measurements estimated that internal scatter contributed 20% of the fetal dose, leakage 20%, collimator scatter 33%, and block scatter 27%. For case 2, clinical and phantom measurements estimated fetal dose to be 0.04% of the tumor dose, corresponding to a total fetal dose of 0.03 Gy for a tumor dose of 78.0 Gy. Leakage contributed 74% of the fetal dose, internal scatter 13%, collimator scatter 9%, and wedge scatter 4%. Conclusions: When indicated, brain tumors may be irradiated to high dose during pregnancy resulting in fetal exposure < 0.10 Gy, conferring an increased but acceptable risk of leukemia in the child, but no other deleterious effects to the fetus after the fourth week of gestation. For our particular field arrangements and linear accelerators, internal scatter contributed a small component of fetal dose compared to leakage and scatter from the collimators and blocks, and 18 MV photons resulted in a higher estimated fetal dose than 6 MV photons due to increased leakage and collimator scatter. These findings are not universal, but clinical and phantom TLD measurements estimate fetal dose accurately for energies < 10 MV and should be taken for each pregnant patient

  6. The computational power of astrocyte mediated synaptic plasticity

    Directory of Open Access Journals (Sweden)

    Rogier Min

    2012-11-01

    Full Text Available Research in the last two decades has made clear that astrocytes play a crucial role in the brain beyond their functions in energy metabolism and homeostasis. Many studies have shown that astrocytes can dynamically modulate neuronal excitability and synaptic plasticity, and might participate in higher brain functions like learning and memory. With the plethora of astrocyte-mediated signaling processes described in the literature today, the current challenge is to identify which of these processes happen under what physiological condition, and how this shapes information processing and, ultimately, behavior. To answer these questions will require a combination of advanced physiological, genetical and behavioral experiments. Additionally, mathematical modeling will prove crucial for testing predictions on the possible functions of astrocytes in neuronal networks, and to generate novel ideas as to how astrocytes can contribute to the complexity of the brain. Here, we aim to provide an outline of how astrocytes can interact with neurons. We do this by reviewing recent experimental literature on astrocyte-neuron interactions, discussing the dynamic effects of astrocytes on neuronal excitability and short- and long-term synaptic plasticity. Finally, we will outline the potential computational functions that astrocyte-neuron interactions can serve in the brain. We will discuss how astrocytes could govern metaplasticity in the brain, how they might organize the clustering of synaptic inputs, and how they could function as memory elements for neuronal activity. We conclude that astrocytes can enhance the computational power of neuronal networks in previously unexpected ways.

  7. Assessment of functional status in children with brain tumors

    International Nuclear Information System (INIS)

    Thirty children treated for brain tumors between 1978 - 1985 at Kurume university hospital were evaluated for alternation in intellectual, emotional, and social function. They were 15 males and 15 females, aged 3 to 16 years, on the averaged 1.7 years after treatment. Twenty-eight children had no neurological deficits and 2 children had slight neurological deficits. It was possible for twenty-eight children to be evaluated for intelligence quotient by Wechsler Intelligence Scale for Children-revised and Tanaka-Binet. The median score and standard deviation of intelligence quotient (IQ) test in children with brain tumors were as follows; verbal IQ: 84 ± 16, performance IQ: 77 ± 20, full scale IQ: 80 ± 20. There children with brain tumors obtained significant low IQ scores than children (t-test, P < 0.01). Twenty-one (72 %) children showed subnormal IQ scores (IQ < 90) and 7 children showed normal IQ scores (IQ ≥ 90). Concerning social and emotional function, twelve children (45.7 %) showed abnormal behaviour. The median scores and standard deviation of IQ scores in cranial irradiated patients were as follows; verbal IQ: 79 ± 13, performance IQ: 71 ± 15, full scale IQ: 71 ± 14. Especially, ten of twelve cranial irradiated patients showed subnormal IQ scores. Also, cranial irradiated patients obtained significant low IQ scores than non-cranial irradiated patients (t-test, P < 0.05). Serial evaluation of three cranial irradiated patients revealed further deterioration without recurrence of tumor and hydrocephalus. The results are discussed to: (1) the effects and mechanism of cranial irradiation on cognitive development: (2) the relationship between cognitive dysfunction and irradiation methods. The effects and mechanism of cranial irradiation on cognitive dysfunction is considered to be not only injury of cortex but also injury of fiber tracts. Also, cognitive dysfunction is apt to be related to age of irradiated patients. (J.P.N.)

  8. Utility of C-11 Choline PET for brain tumors

    International Nuclear Information System (INIS)

    The purpose of the present study was to assess the clinical potential of methyl-11C choline (C-11 choline) in brain tumors. The results of magnetic resonance (MR) imaging in 23 patients suspected of having brain tumors were then compared to the results of C-11 choline and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET). PET with C-11 choline and FDG, in addition to gadolinium-enhanced MR, were performed in these patients. A pathological diagnosis was made for each patient by open surgery. The standardized uptake values (SUVs) of brain tumors and the tumor-to-white matter count (T/W) ratios were determined. The degree of C-11 choline accumulation noted in PET images was compared to the gadolinium-enhanced areas of MR images. The mean T/W ratio of high-grade gliomas was found to be higher than that of low-grade gliomas. This difference was statistically significant (mean±SD: 8.7±6.2, n=9 versus 1.5±0.7 respectively, n=5, p<0.03) when data pertaining to the prominent uptake of C-11 choline by a patient with a pilocytic astrocytoma was excluded. C-11 choline PET failed to detect non-neoplastic lesions in two patients. Areas of C-11 choline accumulation in PET scans were longer than areas visualized by contrast enhancement on MR images in five cases involving high-grade gliomas. C-11 choline PET differentiated between low-grade gliomas and high-grade gliomas, but did not differentiate between low-grade gliomas and non-neoplasms. A combination of C-11 choline PET and MR imaging may provide investigators with accurate means to identify high-grade gliomas. (author)

  9. Utility of C-11 Choline PET for brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Ohtani, Toshiyuki; Hashiba, Yasuhiro; Tosaka, Masahiko; Fujimaki, Hiroya; Sasaki, Tomio; Oriuchi, Noboru [Gunma Univ., Maebashi (Japan). School of Medicine; Inoue, Tomio [Yokohama City Univ. (Japan). School of Medicine

    2002-03-01

    The purpose of the present study was to assess the clinical potential of methyl-{sup 11}C choline (C-11 choline) in brain tumors. The results of magnetic resonance (MR) imaging in 23 patients suspected of having brain tumors were then compared to the results of C-11 choline and {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET). PET with C-11 choline and FDG, in addition to gadolinium-enhanced MR, were performed in these patients. A pathological diagnosis was made for each patient by open surgery. The standardized uptake values (SUVs) of brain tumors and the tumor-to-white matter count (T/W) ratios were determined. The degree of C-11 choline accumulation noted in PET images was compared to the gadolinium-enhanced areas of MR images. The mean T/W ratio of high-grade gliomas was found to be higher than that of low-grade gliomas. This difference was statistically significant (mean{+-}SD: 8.7{+-}6.2, n=9 versus 1.5{+-}0.7 respectively, n=5, p<0.03) when data pertaining to the prominent uptake of C-11 choline by a patient with a pilocytic astrocytoma was excluded. C-11 choline PET failed to detect non-neoplastic lesions in two patients. Areas of C-11 choline accumulation in PET scans were longer than areas visualized by contrast enhancement on MR images in five cases involving high-grade gliomas. C-11 choline PET differentiated between low-grade gliomas and high-grade gliomas, but did not differentiate between low-grade gliomas and non-neoplasms. A combination of C-11 choline PET and MR imaging may provide investigators with accurate means to identify high-grade gliomas. (author)

  10. Injury and repair of astrocyte after ionizing radiation

    International Nuclear Information System (INIS)

    Astrocyte is the most glial cell in the central nervous system. In the present experiment, radiation injury to the central nervous system (CNS) triggers a large network of cellular changes including neuron, glial cell and endothelial cell in morphology and metabolism and function. Astrocyte changes rapidly after ionizing radiation. There is a relationship between astrocyte and the pathologic process and function recover of damaged brain tissue following CNS injury. This suggests that astrocyte plays an important role in cure of clinical radiation injury

  11. Target cell-specific modulation of neuronal activity by astrocytes

    OpenAIRE

    Kozlov, A. S.; Angulo, M. C.; Audinat, E.; Charpak, S

    2006-01-01

    Interaction between astrocytes and neurons enriches the behavior of brain circuits. By releasing glutamate and ATP, astrocytes can directly excite neurons and modulate synaptic transmission. In the rat olfactory bulb, we demonstrate that the release of GABA by astrocytes causes long-lasting and synchronous inhibition of mitral and granule cells. In addition, astrocytes release glutamate, leading to a selective activation of granule-cell NMDA receptors. Thus, by releasing excitatory and inhibi...

  12. Factors affecting radiation injury after interstitial brachytherapy for brain tumors

    International Nuclear Information System (INIS)

    The effects of brachytherapy on normal brain tissue are not easily delineated in the clinical setting because of the presence of concurrent radiation-induced changes in the coexistent brain tumor. Sequential morphologic studies performed after the implantation of radioactive sources into the brains of experimental animals have provided a better understanding of the character and magnitude of the structural changes produced by interstitial irradiation on normal brain tissue. Furthermore, the clinical experience accumulated thus far provides not only relevant information, but also some guidelines for future treatment policies. In this paper, the authors summarize the experimental findings and review the pathologic and clinical features of brain injury caused by interstitial brachytherapy. A number of studies in the older literature examined the effects of radioisotopes such as radium-226 (38--43), radon-22 (44--46), gold-198 (29,47--50), tantalum-182 (29,51,52) yttrium-9- (50,53,54), and cobalt-60 (29,50,55). This review is restricted to low- and high-activity encapsulated iodine-125 (125I) and iridium-192 (192Ir), the isotopes that are most commonly used in current clinical practice

  13. Simulating ‘structure-function’ patterns of malignant brain tumors

    Science.gov (United States)

    Mansury, Yuri; Deisboeck, Thomas S.

    2004-01-01

    Rapid growth and extensive tissue infiltration are characteristics of highly malignant neuroepithelial brain tumors. Very little is known, however, about the existence of structure-function relationships in these types of neoplasm. Therefore, using a previously developed two-dimensional agent-based model, we have investigated the emergent patterns of multiple tumor cells that proliferate and migrate on an adaptive grid lattice, driven by a local-search mechanism and guided by the presence of distinct environmental conditions. Numerical results indicate a strong correlation between the fractal dimensions of the tumor surface and the average velocity of the tumor's spatial expansion. In particular, when the so called ‘beaten-path advantage’ intensifies, i.e., rising ‘mechanical rewards’ for cells to follow each other along preformed pathways, it results in an increase of the tumor system's fractal dimensions leading to a concomitant acceleration of its spatial expansion. Whereas cell migration is the dominant phenotype responsible for the more extensive branching patterns exhibiting higher fractal dimensions, cell proliferation appears to become more active primarily at lower fracticality associated with stronger mechanical confinements. Implications of these results for experimental and clinical cancer research are discussed.

  14. Detection of Brain Tumor in EEG Signals Using Independent Component Analysis

    OpenAIRE

    Rashid, Akram; Tahir, Seema; Choudhury, Aamer Saleem

    2015-01-01

    The Electroencephalogram(EEG) is Scientifically becoming an important tool of measuring brain activity. The EEG data is used to diagnose brain diseases and brain abnormalities. EEG helps to suit the increasing demand of brain tumor detection on affordable prices with better clinical and healthcare services. This research work presents a technique of efficient brain tumor detection in EEG signals using Independent Component Analysis(ICA). EEG signals which actually are carrying information reg...

  15. Analysis of Spectral Features of EEG signal in Brain Tumor Condition

    Directory of Open Access Journals (Sweden)

    Selvam V. Salai

    2015-08-01

    Full Text Available The scalp electroencephalography (EEG signal is an important clinical tool for the diagnosis of several brain disorders. The objective of the presented work is to analyze the feasibility of the spectral features extracted from the scalp EEG signals in detecting brain tumors. A set of 16 candidate features from frequency domain is considered. The significance on the mean values of these features between 100 brain tumor patients and 102 normal subjects is statistically evaluated. Nine of the candidate features significantly discriminate the brain tumor case from the normal one. The results encourage the use of (quantitative scalp EEG for the diagnosis of brain tumors

  16. The neuroblast and angioblast chemotaxic factor SDF-1 (CXCL12 expression is briefly up regulated by reactive astrocytes in brain following neonatal hypoxic-ischemic injury

    Directory of Open Access Journals (Sweden)

    Walker Aisha L

    2005-10-01

    Full Text Available Abstract Background Stromal cell-derived factor 1 (SDF-1 or CXCL12 is chemotaxic for CXCR4 expressing bone marrow-derived cells. It functions in brain embryonic development and in response to ischemic injury in helping guide neuroblast migration and vasculogenesis. In experimental adult stroke models SDF-1 is expressed perivascularly in the injured region up to 30 days after the injury, suggesting it could be a therapeutic target for tissue repair strategies. We hypothesized that SDF-1 would be expressed in similar temporal and spatial patterns following hypoxic-ischemic (HI injury in neonatal brain. Results Twenty-five 7-day-old C57BL/J mice underwent HI injury. SDF-1 expression was up regulated up to 7 days after the injury but not at the later time points. The chief sites of SDF-1 up regulation were astrocytes, their foot processes along blood vessels and endothelial cells. Conclusion The localization of SDF-1 along blood vessels in the HI injury zone suggests that these perivascular areas are where chemotaxic signaling for cellular recruitment originates and that reactive astrocytes are major mediators of this process. The associated endothelium is likely to be the site for vascular attachment and diapedesis of CXCR4 receptor expressing cells to enter the injured tissue. Here we show that, relative to adults, neonates have a significantly smaller window of opportunity for SDF-1 based vascular chemotaxic recruitment of bone marrow-derived cells. Therefore, without modification, following neonatal HI injury there is only a narrow period of time for endogenous SDF-1 mediated chemotaxis and recruitment of reparative cells, including exogenously administered stem/progenitor cells.

  17. Round Randomized Learning Vector Quantization for Brain Tumor Imaging

    Directory of Open Access Journals (Sweden)

    Siti Norul Huda Sheikh Abdullah

    2016-01-01

    Full Text Available Brain magnetic resonance imaging (MRI classification into normal and abnormal is a critical and challenging task. Owing to that, several medical imaging classification techniques have been devised in which Learning Vector Quantization (LVQ is amongst the potential. The main goal of this paper is to enhance the performance of LVQ technique in order to gain higher accuracy detection for brain tumor in MRIs. The classical way of selecting the winner code vector in LVQ is to measure the distance between the input vector and the codebook vectors using Euclidean distance function. In order to improve the winner selection technique, round off function is employed along with the Euclidean distance function. Moreover, in competitive learning classifiers, the fitting model is highly dependent on the class distribution. Therefore this paper proposed a multiresampling technique for which better class distribution can be achieved. This multiresampling is executed by using random selection via preclassification. The test data sample used are the brain tumor magnetic resonance images collected from Universiti Kebangsaan Malaysia Medical Center and UCI benchmark data sets. Comparative studies showed that the proposed methods with promising results are LVQ1, Multipass LVQ, Hierarchical LVQ, Multilayer Perceptron, and Radial Basis Function.

  18. Round Randomized Learning Vector Quantization for Brain Tumor Imaging

    Science.gov (United States)

    2016-01-01

    Brain magnetic resonance imaging (MRI) classification into normal and abnormal is a critical and challenging task. Owing to that, several medical imaging classification techniques have been devised in which Learning Vector Quantization (LVQ) is amongst the potential. The main goal of this paper is to enhance the performance of LVQ technique in order to gain higher accuracy detection for brain tumor in MRIs. The classical way of selecting the winner code vector in LVQ is to measure the distance between the input vector and the codebook vectors using Euclidean distance function. In order to improve the winner selection technique, round off function is employed along with the Euclidean distance function. Moreover, in competitive learning classifiers, the fitting model is highly dependent on the class distribution. Therefore this paper proposed a multiresampling technique for which better class distribution can be achieved. This multiresampling is executed by using random selection via preclassification. The test data sample used are the brain tumor magnetic resonance images collected from Universiti Kebangsaan Malaysia Medical Center and UCI benchmark data sets. Comparative studies showed that the proposed methods with promising results are LVQ1, Multipass LVQ, Hierarchical LVQ, Multilayer Perceptron, and Radial Basis Function.

  19. Boron Neutron Capture Therapy for Malignant Brain Tumors

    Science.gov (United States)

    MIYATAKE, Shin-Ichi; KAWABATA, Shinji; HIRAMATSU, Ryo; KUROIWA, Toshihiko; SUZUKI, Minoru; KONDO, Natsuko; ONO, Koji

    2016-01-01

    Boron neutron capture therapy (BNCT) is a biochemically targeted radiotherapy based on the nuclear capture and fission reactions that occur when non-radioactive boron-10, which is a constituent of natural elemental boron, is irradiated with low energy thermal neutrons to yield high linear energy transfer alpha particles and recoiling lithium-7 nuclei. Therefore, BNCT enables the application of a high dose of particle radiation selectively to tumor cells in which boron-10 compound has been accumulated. We applied BNCT using nuclear reactors for 167 cases of malignant brain tumors, including recurrent malignant gliomas, newly diagnosed malignant gliomas, and recurrent high-grade meningiomas from January 2002 to May 2014. Here, we review the principle and history of BNCT. In addition, we introduce fluoride-18-labeled boronophenylalanine positron emission tomography and the clinical results of BNCT for the above-mentioned malignant brain tumors. Finally, we discuss the recent development of accelerators producing epithermal neutron beams. This development could provide an alternative to the current use of specially modified nuclear reactors as a neutron source, and could allow BNCT to be performed in a hospital setting. PMID:27250576

  20. CyberKnife stereotactic irradiation for metastatic brain tumors

    International Nuclear Information System (INIS)

    The CyberKnife provides a new technique for performing frameless stereotactic irradiation. So far, few reports have been published on clinical outcomes obtained with the CyberKnife. This report summarizes our clinical experience with CyberKnife irradiation for metastatic brain tumors. Seventy-seven lesions (48 patients) were evaluated and analyzed, and 66 lesions in 41 patients were treated with stereotactic radiosurgery (SRS). The prescribed dose was 9 to 30 Gy. Freedom from progression of the tumors was more likely with a prescribed dose of at least 24 Gy than with one of less than 20 Gy (p=0.0244; log-rank test). The CR (complete response) rate was significantly higher when D99 was at least 24 Gy (p=0.0045). There were no severe side effects. Stereotactic irradiation with the CyberKnife for metastatic brain tumors is effective and safe. D99 should be at least 24 Gy for CyberKnife SRS treatment. (author)

  1. Exploratory case-control study of brain tumors in adults

    International Nuclear Information System (INIS)

    An exploratory study of brain tumors in adults was carried out using 215 cases diagnosed in Southern Ontario between 1979 and 1982, with an individually matched, hospital control series. Significantly elevated risks were observed for reported use of spring water, drinking of wine, and consumption of pickled fish, together with a significant protective effect for the regular consumption of any of several types of fruit. While these factors are consistent with a role for N-nitroso compounds in the etiology of these tumors, for several other factors related to this hypothesis, no association was observed. Occupation in the rubber industry was associated with a significant relative risk of 9.0, though no other occupational associations were seen. Two previously unreported associations were with smoking nonfilter cigarettes with a significant trend and with the use of hair dyes or sprays. The data do not support an association between physical head trauma requiring medical attention and risk of brain tumors and indicate that exposure to ionizing radiation and vinyl chloride monomer does not contribute any appreciable fraction of attributable risk in the population studied. The findings warrant further detailed investigation in future epidemiologic studies

  2. Association of astrocytes with neurons and astrocytes derived from distinct progenitor domains in the subpallium

    OpenAIRE

    Makio Torigoe; Kenta Yamauchi; Yan Zhu; Hiroaki Kobayashi; Fujio Murakami

    2015-01-01

    Astrocytes play pivotal roles in metabolism and homeostasis as well as in neural development and function in a manner thought to depend on their region-specific diversity. In the mouse spinal cord, astrocytes and neurons, which are derived from a common progenitor domain (PD) and controlled by common PD-specific transcription factors, migrate radially and share their final positions. However, whether astrocytes can only interact with neurons from common PDs in the brain remains unknown. Here,...

  3. Brain-borne IL-1 adjusts glucoregulation and provides fuel support to astrocytes and neurons in an autocrine/paracrine manner.

    Science.gov (United States)

    Del Rey, A; Verdenhalven, M; Lörwald, A C; Meyer, C; Hernangómez, M; Randolf, A; Roggero, E; König, A M; Heverhagen, J T; Guaza, C; Besedovsky, H O

    2016-09-01

    It is still controversial which mediators regulate energy provision to activated neural cells, as insulin does in peripheral tissues. Interleukin-1β (IL-1β) may mediate this effect as it can affect glucoregulation, it is overexpressed in the 'healthy' brain during increased neuronal activity, and it supports high-energy demanding processes such as long-term potentiation, memory and learning. Furthermore, the absence of sustained neuroendocrine and behavioral counterregulation suggests that brain glucose-sensing neurons do not perceive IL-1β-induced hypoglycemia. Here, we show that IL-1β adjusts glucoregulation by inducing its own production in the brain, and that IL-1β-induced hypoglycemia is myeloid differentiation primary response 88 protein (MyD88)-dependent and only partially counteracted by Kir6.2-mediated sensing signaling. Furthermore, we found that, opposite to insulin, IL-1β stimulates brain metabolism. This effect is absent in MyD88-deficient mice, which have neurobehavioral alterations associated to disorders in glucose homeostasis, as during several psychiatric diseases. IL-1β effects on brain metabolism are most likely maintained by IL-1β auto-induction and may reflect a compensatory increase in fuel supply to neural cells. We explore this possibility by directly blocking IL-1 receptors in neural cells. The results showed that, in an activity-dependent and paracrine/autocrine manner, endogenous IL-1 produced by neurons and astrocytes facilitates glucose uptake by these cells. This effect is exacerbated following glutamatergic stimulation and can be passively transferred between cell types. We conclude that the capacity of IL-1β to provide fuel to neural cells underlies its physiological effects on glucoregulation, synaptic plasticity, learning and memory. However, deregulation of IL-1β production could contribute to the alterations in brain glucose metabolism that are detected in several neurologic and psychiatric diseases. PMID:26643538

  4. Early Experience of Pre- and Post-Contrast 7.0T MRI in Brain Tumors

    OpenAIRE

    Paek, Seung Leal; Chung, Young Seob; Paek, Sun Ha; Hwang, Jae Ha; Sohn, Chul-Ho; Choi, Seung Hong; Son, Young Don; Kim, Young Bo; Kim, Dong Gyu; Lee, Kendall H.; Cho, Zang-Hee

    2013-01-01

    We investigated the safety and clinical applicability of 7.0 Tesla (T) brain magnetic resonance imaging (MRI) in patients with brain tumors. Twenty-four patients with intraaxial or extraaxial brain tumors were enrolled in this study. 7.0T MRIs of T2*-weighted axial and T1-weighted coronal or sagittal images were obtained and compared with 1.5T brain MRIs. The T2*-weighted images from 7.0T brain MRI revealed detailed microvasculature and the internal contents of supratentorial brain tumors bet...

  5. Astrocytes release ATP through lysosomal exocytosis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Astrocytes, the most abundant type of glial cells in the brain, have been found to release signaling molecules, including adenosine triphosphate(ATP), the most important energy carrier inside the cell as well as a universal extracellular signaling molecule.

  6. Identifying the needs of brain tumor patients and their caregivers.

    Science.gov (United States)

    Parvataneni, Rupa; Polley, Mei-Yin; Freeman, Teresa; Lamborn, Kathleen; Prados, Michael; Butowski, Nicholas; Liu, Raymond; Clarke, Jennifer; Page, Margaretta; Rabbitt, Jane; Fedoroff, Anne; Clow, Emelia; Hsieh, Emily; Kivett, Valerie; Deboer, Rebecca; Chang, Susan

    2011-09-01

    The purpose of this study is to identify the needs of brain tumor patients and their caregivers to provide improved health services to these populations. Two different questionnaires were designed for patients and caregivers. Both questionnaires contained questions pertaining to three realms: disease symptoms/treatment, health care provider, daily living/finances. The caregivers' questionnaires contained an additional domain on emotional needs. Each question was evaluated for the degree of importance and satisfaction. Exploratory analyses determined whether baseline characteristics affect responder importance or satisfaction. Also, areas of high agreement/disagreement in satisfaction between the participating patient-caregiver pairs were identified. Questions for which >50% of the patients and caregivers thought were "very important" but >30% were dissatisfied include: understanding the cause of brain tumors, dealing with patients' lower energy, identifying healthful foods and activities for patients, telephone access to health care providers, information on medical insurance coverage, and support from their employer. In the emotional realm, caregivers identified 9 out of 10 items as important but need further improvement. Areas of high disagreement in satisfaction between participating patient-caregiver pairs include: getting help with household chores (P value = 0.006) and finding time for personal needs (P value < 0.001). This study provides insights into areas to improve services for brain tumor patients and their caregivers. The caregivers' highest amount of burden is placed on their emotional needs, emphasizing the importance of providing appropriate medical and psychosocial support for caregivers to cope with emotional difficulties they face during the patients' treatment process. PMID:21311950

  7. Proton and carbon ion radiotherapy for primary brain tumors and tumors of the skull base

    Energy Technology Data Exchange (ETDEWEB)

    Combs, Stephanie E.; Kessel, Kerstin; Habermehl, Daniel; Debus, Jurgen [Univ. Hospital of Heidelberg, Dept. of Radiation Oncology, Heidelberg (Germany)], e-mail: Stephanie.Combs@med.uni-heidelberg.de; Haberer, Thomas [Heidelberger Ionenstrahl Therapiezentrum (HIT), Heidelberg (Germany); Jaekel, Oliver [Univ. Hospital of Heidelberg, Dept. of Radiation Oncology, Heidelberg (Germany); Heidelberger Ionenstrahl Therapiezentrum (HIT), Heidelberg (Germany)

    2013-10-15

    To analyze clinical concepts, toxicity and treatment outcome in patients with brain and skull base tumors treated with photons and particle therapy. Material and methods: In total 260 patients with brain tumors and tumors of the skull base were treated at the Heidelberg Ion Therapy Center (HIT). Patients enrolled in and randomized within prospective clinical trials as well as bony or soft tissue tumors are not included in this analysis. Treatment was delivered as protons, carbon ions, or combinations of photons and a carbon ion boost. All patients are included in a tight follow-up program. The median follow-up time is 12 months (range 2-39 months). Results: Main histologies included meningioma (n = 107) for skull base lesions, pituitary adenomas (n = 14), low-grade gliomas (n = 51) as well as high-grade gliomas (n = 55) for brain tumors. In all patients treatment could be completed without any unexpected severe toxicities. No side effects > CTC Grade III were observed. To date, no severe late toxicities were observed, however, for endpoints such as secondary malignancies or neuro cognitive side effects follow-up time still remains too short. Local recurrences were mainly seen in the group of high-grade gliomas or atypical meningiomas; for benign skull base meningiomas, to date, no recurrences were observed during follow-up. Conclusion: The specific benefit of particle therapy will potentially reduce the risk of secondary malignancies as well as improve neuro cognitive outcome and quality of life (QOL); thus, longer follow-up will be necessary to confirm these endpoints. Indication-specific trials on meningiomas and gliomas are underway to elucidate the role of protons and carbon ions in these indications.

  8. Proton and carbon ion radiotherapy for primary brain tumors and tumors of the skull base

    International Nuclear Information System (INIS)

    To analyze clinical concepts, toxicity and treatment outcome in patients with brain and skull base tumors treated with photons and particle therapy. Material and methods: In total 260 patients with brain tumors and tumors of the skull base were treated at the Heidelberg Ion Therapy Center (HIT). Patients enrolled in and randomized within prospective clinical trials as well as bony or soft tissue tumors are not included in this analysis. Treatment was delivered as protons, carbon ions, or combinations of photons and a carbon ion boost. All patients are included in a tight follow-up program. The median follow-up time is 12 months (range 2-39 months). Results: Main histologies included meningioma (n = 107) for skull base lesions, pituitary adenomas (n = 14), low-grade gliomas (n = 51) as well as high-grade gliomas (n = 55) for brain tumors. In all patients treatment could be completed without any unexpected severe toxicities. No side effects > CTC Grade III were observed. To date, no severe late toxicities were observed, however, for endpoints such as secondary malignancies or neuro cognitive side effects follow-up time still remains too short. Local recurrences were mainly seen in the group of high-grade gliomas or atypical meningiomas; for benign skull base meningiomas, to date, no recurrences were observed during follow-up. Conclusion: The specific benefit of particle therapy will potentially reduce the risk of secondary malignancies as well as improve neuro cognitive outcome and quality of life (QOL); thus, longer follow-up will be necessary to confirm these endpoints. Indication-specific trials on meningiomas and gliomas are underway to elucidate the role of protons and carbon ions in these indications

  9. Combined therapy of radiotherapy and chemotherapy on brain tumor

    International Nuclear Information System (INIS)

    The subjects were 52 patients (5-78 years, average 51.4 years) with primary brain tumor treated in 4 institutes in Chugoku and Shikoku districts during 3 years from April 1991. Histopathologically, the subject diseases were glioblastoma in 16, well differentiated glioblastoma in 19, brain primary lymphoma in 9, and malignant meningioma in 5. In the glioblastoma group, 14 received surgery, radiotherapy, and chemotherapy at the first admission. Three patients who survived more than 1 year and 6 patients who died within 1 year were compared. No significant difference was observed in terms of radiotherapy between the both groups. In the astrocytoma and oligodendroglioma groups, 16 patients received radiotherapy and chemotherapy as the initial treatment, and 14 underwent several course of maintenance therapy. In the comparison between 7 patients who died within 3 years from the first treatment and 9 patients surviving more than 3 years, no significant difference was observed in terms of radiation doses. (S.Y.)

  10. Collective Behavior of Brain Tumor Cells: the Role of Hypoxia

    Science.gov (United States)

    Khain, Evgeniy; Katakowski, Mark; Hopkins, Scott; Szalad, Alexandra; Zheng, Xuguang; Jiang, Feng; Chopp, Michael

    2013-03-01

    We consider emergent collective behavior of a multicellular biological system. Specifically we investigate the role of hypoxia (lack of oxygen) in migration of brain tumor cells. We performed two series of cell migration experiments. The first set of experiments was performed in a typical wound healing geometry: cells were placed on a substrate, and a scratch was done. In the second set of experiments, cell migration away from a tumor spheroid was investigated. Experiments show a controversy: cells under normal and hypoxic conditions have migrated the same distance in the ``spheroid'' experiment, while in the ``scratch'' experiment cells under normal conditions migrated much faster than under hypoxic conditions. To explain this paradox, we formulate a discrete stochastic model for cell dynamics. The theoretical model explains our experimental observations and suggests that hypoxia decreases both the motility of cells and the strength of cell-cell adhesion. The theoretical predictions were further verified in independent experiments.

  11. Phenylalanine-coupled solid lipid nanoparticles for brain tumor targeting

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate the targeting potential of amino acid (phenylalanine)-coupled solid lipid nanoparticles (SLN) loaded with ionically complexed doxorubicin HCl (Dox). Ionic complexation was used to enhance the loading efficiency and release characteristics of water soluble form of Dox. l-Type amino acid transporters (LAT1) are highly expressed on blood brain barrier as well as on many brain cancer cells, thus targeting LAT1 using phenylalanine improved anticancer activity of prepared nanocarrier. The phenylalanine-coupled SLN were characterized by fourier transform infrared spectroscopy, scanning electron microscope, transmission electron microscopy, particle size, zeta potential, entrapment efficiency and in vitro release. The particle size of the resulting SLN was found to be in the range of 163.3 ± 5.2 to 113.0 ± 2.6 nm, with a slightly negative surface charge. In ex vivo study on C6 glioma cell lines, the cellular cytotoxicity of the SLN was highly increased when coupled with phenylalanine. In addition, stealthing sheath of PEG present on the surface of the SLN enhanced the cellular uptake of the SLN on C6 glioma cell line. Results of biodistribution and fluorescence studies clearly revealed that phenylalanine-coupled SLN could deliver high amount of drug into the brain tumor cells and showed the brain-targeting potential

  12. Relaxin Protects Astrocytes from Hypoxia In Vitro

    OpenAIRE

    Willcox, Jordan M.; Alastair J S Summerlee

    2014-01-01

    The peptide relaxin has recently been shown to protect brain tissues from the detrimental effects of ischemia. To date, the mechanisms for this remain unclear. In order to investigate the neuroprotective mechanisms by which relaxin may protect the brain, we investigated the possibility that relaxin protects astrocytes from hypoxia or oxygen/glucose deprivation (OGD). Cultured astrocytes were pre-treated with either relaxin-2 or relaxin-3 and exposed to OGD for 24 or 48 hours. Following OGD ex...

  13. Early dynamic Thallium-201 SPECT in evaluation of brain tumors

    International Nuclear Information System (INIS)

    Purpose: We performed early dynamic 201TlCl SPECT studies on patients with brain tumors to determine the value of 201TlCl dynamics for 15 minutes in distinguishing and evaluating the histologic grade of brain tumors. Method: SPECT studies were performed on 69 patients with brain tumors prior to surgical resection. Histological diagnosis was as follows: 28 patients with glioblastoma (grade IV), 8 patients with anaplastic astrocytoma (grade III), 5 patients with grade II astrocytoma, 1 patients with pilocytic astrocytoma (grade I), and 27 patients with meningioma. Pilocytic astrocytoma and grade II astrocytoma were grouped together as low-grade gliomas. Results: In glioblastomas, the Time-activity ratios(TARs) increased significantly at 6 min (99.2±6.0%, p<0.0001 ), 9 min (103.0±4.6%, p<0.0001), 12 min (102.1±6.4%, p<0.01), and 15 min (102.0±5.0%, p<0.001) after 201TlCl administration when compared to the TAR at 3 min (93.7±6.9%). Unchanged radioactivity was observed on the time-activity curve in anaplastic astrocytomas (3 min: 106.0±17.8%, 6 min: 103.8±9.4%, 9 min: 99.1±6.3%, 12 min: 95.0±11.0%, 15 min: 96.0±13.0%). The TARs decreased significantly at 6 min (104.0±7.1%, p<0.05), 9 min (96.1±4.9%, p<0.02), 12 min(95.0±6.5%, p<0.05), and 15 min (89.8±12.8%, p<0.05) compared to the TAR at 3 min (113.9±9.5%) in low grade gliomas. In meningiomas, the TARs decreased at 12 min (94.0±9.1%, p<0.01), and 15 min (93.6±12.8%, p<0.02) compared to the TAR at 3 min (108.6±18.5%) respectively. Conclusion: In this early dynamic SPECT study, the entire duration of the examination is short, 15 minutes, a period similar to other general laboratory tests. Moreover, there is no need for adjustments of the imaging location with this method since continuous scanning is utilized. This examination method indicated not only 201Tl uptake but accumulative dynamics and also offer more accurate assessment in the diagnosis of brain tumors

  14. Criteria for the evaluation of brachytherapy for malignant brain tumors

    International Nuclear Information System (INIS)

    Thirty two patients with recurrent or unresectable malignant brain tumors were treated by interstitial brachytherapy with Ir-192 seeds. After-loading catheters were stereotactically implanted under local anesthesia using a Brown-Roberts-wells (BRW) CT guided stereotactic system. The response to the therapy was followed by serial CT and MRI scans and evaluated three months after implantation by the standard criteria for the evaluation of chemotherapy because there is no set of criteria available for radiation therapy. After interstitial brachytherapy, the most commonly observed CT and MRI finding was central low attenuation, that is, the central enhanced tumor replaced by the radiation necrosis. Three months after the treatment, these findings were observed in 23 patients out of 32 patients on the CT and MRI. We observed complete response (CR) in 6 of 32 patients, partial response (PR) in 9, no change (NC) in 7 and progressive disease (PD) in 9. In 6 CR patients, the tumor disappeared by three months after treatment. In 15 patients of 17 NC and PD patients, the central low attenuation was observed and their prognosis was better than those without central necrosis. The results suggested the standard criteria for the evaluation of chemotherapy, such as CR, PR etc, cannot be applicable to our series because the tumor mass replaced by necrotic tissue and remained as a mass lesion in most cases and new criteria in consideration of this low attenuation on CT and MRI will be needed for the evaluation of brachytherapy on neuroimagings. (author)

  15. P03.09PHARMACOLOGICAL MODULATION OF BLOOD-BRAIN BARRIER: FUTURE STRATEGY FOR TREATMENT OF BRAIN TUMORS

    OpenAIRE

    Sardi, I.; Cardellicchio, S.; Iorio, A.L.; da Ros, M.; la Marca, G.; Giunti, L.; Massimino, M.; L. Genitori

    2014-01-01

    A prerequisite for the efficacy of chemotherapy is that it reaches the tumor mass at a therapeutic concentration. In brain tumors this phenomenon is hampered by the presence of the blood brain barrier (BBB) which limits the spread of chemotherapeutic agents within the brain. It is lately emerged as this Multi Drug Resistance (MDR) phenomenon is explained through the cooperation of P-glycoprotein (P-gp, ABCB1) and breast cancer resistance protein (BCRP, ABCG2), two “gatekeeper" transporters th...

  16. Functional Oxygen Sensitivity of Astrocytes.

    Science.gov (United States)

    Angelova, Plamena R; Kasymov, Vitaliy; Christie, Isabel; Sheikhbahaei, Shahriar; Turovsky, Egor; Marina, Nephtali; Korsak, Alla; Zwicker, Jennifer; Teschemacher, Anja G; Ackland, Gareth L; Funk, Gregory D; Kasparov, Sergey; Abramov, Andrey Y; Gourine, Alexander V

    2015-07-22

    In terrestrial mammals, the oxygen storage capacity of the CNS is limited, and neuronal function is rapidly impaired if oxygen supply is interrupted even for a short period of time. However, oxygen tension monitored by the peripheral (arterial) chemoreceptors is not sensitive to regional CNS differences in partial pressure of oxygen (PO2 ) that reflect variable levels of neuronal activity or local tissue hypoxia, pointing to the necessity of a functional brain oxygen sensor. This experimental animal (rats and mice) study shows that astrocytes, the most numerous brain glial cells, are sensitive to physiological changes in PO2 . Astrocytes respond to decreases in PO2 a few millimeters of mercury below normal brain oxygenation with elevations in intracellular calcium ([Ca(2+)]i). The hypoxia sensor of astrocytes resides in the mitochondria in which oxygen is consumed. Physiological decrease in PO2 inhibits astroglial mitochondrial respiration, leading to mitochondrial depolarization, production of free radicals, lipid peroxidation, activation of phospholipase C, IP3 receptors, and release of Ca(2+) from the intracellular stores. Hypoxia-induced [Ca(2+)]i increases in astrocytes trigger fusion of vesicular compartments containing ATP. Blockade of astrocytic signaling by overexpression of ATP-degrading enzymes or targeted astrocyte-specific expression of tetanus toxin light chain (to interfere with vesicular release mechanisms) within the brainstem respiratory rhythm-generating circuits reveals the fundamental physiological role of astroglial oxygen sensitivity; in low-oxygen conditions (environmental hypoxia), this mechanism increases breathing activity even in the absence of peripheral chemoreceptor oxygen sensing. These results demonstrate that astrocytes are functionally specialized CNS oxygen sensors tuned for rapid detection of physiological changes in brain oxygenation. Significance statement: Most, if not all, animal cells possess mechanisms that allow them to

  17. Astrocytes Underlie Neuroinflammatory Memory Impairment

    OpenAIRE

    Osso, LA; Chan, JR

    2015-01-01

    © 2015 Elsevier Inc. All rights reserved. Neuroinflammation is being increasingly recognized as a potential mediator of cognitive impairments in various neurological conditions. Habbas et al. demonstrate that the pro-inflammatory cytokine tumor necrosis factor alpha signals through astrocytes to alter synaptic transmission and impair cognition in a mouse model of multiple sclerosis.

  18. Comparison of two brain tumor-localizing MRI agent. GD-BOPTA and GD-DTPA. MRI and ICP study of rat brain tumor model

    International Nuclear Information System (INIS)

    In this study, we compared the behavior of Gd-BOPTA as a brain tumor selective contrast agent with Gd-DTPA in a common dose of 0.1 mmol/kg. We performed a MRI study using those two agent as contrast material, and we measured tissue Gd-concentrations by ICP-AES. As a result, Gd-BOPTA showed a better MRI enhancement in brain tumor. ICP showed significantly greater uptake of Gd-BOPTA in tumor samples, at all time course peaked at 5 minutes after administration, Gd being retained for a longer time in brain tumor till 2 hours, without rapid elimination as Gd-DTPA. We conclude that Gd-BOPTA is a new useful contrast material for MR imaging in brain tumor and an effective absorption agent for neutron capture therapy for further research. (author)

  19. The role of Intravenous Levetiracetam in Treatment of Seizures in Brain Tumor Patients

    OpenAIRE

    Ekokobe eFonkem; Paul eBricker; Diana eMungall; Jose eAceves; Eromata eEbwe; Wei eTang; Batool F. Kirmani

    2013-01-01

    Levetiracetam, tradename Keppra, is a new second generation antiepileptic drug that is being used increasingly in brain tumor patients. In patients suffering with brain tumors, seizures are one of the leading neurologic complications seen in more than 30% of patients. Levetiracetam is a pyrollidine-derivative drug, which has a unique mechanism of action. Unlike other antiepileptic drugs, Levetiracetam is proposed to bind to a synaptic vesicle protein inhibiting calcium release. Brain tumor...

  20. [Untoward side effects of chemoradiotherapy in children with malignant brain tumors].

    Science.gov (United States)

    Morozova, S K; Begun, I V; Spivak, L V; Radiuk, K A; Papkevich, I I; Savich, T V; Pershaĭ, E B; Vashkevich, T I; Aleĭnikova, O V

    2002-01-01

    Untoward side-effects of chemoradiotherapy were compared in 48 children treated for brain tumors and those in remission lasting from less than 12 months to 11 years. The investigation concerned disturbances in the neurologic, endocrine, cardiovascular, urinary, hepatobiliary and psychic systems; neurologic ones proved the most frequent. No cases of heart failure were reported among patients with brain tumors during remission. Hormonal study revealed inhibited thyroid function in brain tumor sufferers. PMID:12455363

  1. Astrocytic actions on extrasynaptic neuronal currents

    Directory of Open Access Journals (Sweden)

    Balazs ePal

    2015-12-01

    Full Text Available In the last few decades, knowledge about astrocytic functions has significantly increased. It was demonstrated that astrocytes are not passive elements of the central nervous system, but active partners of neurons. There is a growing body of knowledge about the calcium excitability of astrocytes, the actions of different gliotransmitters and their release mechanisms, as well as the participation of astrocytes in the regulation of synaptic functions and their contribution to synaptic plasticity. However, astrocytic functions are even more complex than being a partner of the 'tripartite synapse', as they can influence extrasynaptic neuronal currents either by releasing substances or regulating ambient neurotransmitter levels. Several types of currents or changes of membrane potential with different kinetics and via different mechanisms can be elicited by astrocytic activity. Astrocyte-dependent phasic or tonic, inward or outward currents were described in several brain areas. Such currents, together with the synaptic actions of astrocytes, can contribute to neuromodulatory mechanisms, neurosensory and –secretory processes, cortical oscillatory activity, memory and learning or overall neuronal excitability. This mini-review is an attempt to give a brief summary of astrocyte-dependent extrasynaptic neuronal currents and their possible functional significance.

  2. Trafficking of astrocytic vesicles in hippocampal slices

    International Nuclear Information System (INIS)

    The increasingly appreciated role of astrocytes in neurophysiology dictates a thorough understanding of the mechanisms underlying the communication between astrocytes and neurons. In particular, the uptake and release of signaling substances into/from astrocytes is considered as crucial. The release of different gliotransmitters involves regulated exocytosis, consisting of the fusion between the vesicle and the plasma membranes. After fusion with the plasma membrane vesicles may be retrieved into the cytoplasm and may continue to recycle. To study the mobility implicated in the retrieval of secretory vesicles, these structures have been previously efficiently and specifically labeled in cultured astrocytes, by exposing live cells to primary and secondary antibodies. Since the vesicle labeling and the vesicle mobility properties may be an artifact of cell culture conditions, we here asked whether the retrieving exocytotic vesicles can be labeled in brain tissue slices and whether their mobility differs to that observed in cell cultures. We labeled astrocytic vesicles and recorded their mobility with two-photon microscopy in hippocampal slices from transgenic mice with fluorescently tagged astrocytes (GFP mice) and in wild-type mice with astrocytes labeled by Fluo4 fluorescence indicator. Glutamatergic vesicles and peptidergic granules were labeled by the anti-vesicular glutamate transporter 1 (vGlut1) and anti-atrial natriuretic peptide (ANP) antibodies, respectively. We report that the vesicle mobility parameters (velocity, maximal displacement and track length) recorded in astrocytes from tissue slices are similar to those reported previously in cultured astrocytes.

  3. Trafficking of astrocytic vesicles in hippocampal slices

    Energy Technology Data Exchange (ETDEWEB)

    Potokar, Maja; Kreft, Marko [Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, 1000 Ljubljana (Slovenia); Celica Biomedical Center, Technology Park 24, 1000 Ljubljana (Slovenia); Lee, So-Young; Takano, Hajime; Haydon, Philip G. [Department of Neuroscience, Room 215, Stemmler Hall, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104 (United States); Zorec, Robert, E-mail: Robert.Zorec@mf.uni-lj.si [Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, 1000 Ljubljana (Slovenia); Celica Biomedical Center, Technology Park 24, 1000 Ljubljana (Slovenia)

    2009-12-25

    The increasingly appreciated role of astrocytes in neurophysiology dictates a thorough understanding of the mechanisms underlying the communication between astrocytes and neurons. In particular, the uptake and release of signaling substances into/from astrocytes is considered as crucial. The release of different gliotransmitters involves regulated exocytosis, consisting of the fusion between the vesicle and the plasma membranes. After fusion with the plasma membrane vesicles may be retrieved into the cytoplasm and may continue to recycle. To study the mobility implicated in the retrieval of secretory vesicles, these structures have been previously efficiently and specifically labeled in cultured astrocytes, by exposing live cells to primary and secondary antibodies. Since the vesicle labeling and the vesicle mobility properties may be an artifact of cell culture conditions, we here asked whether the retrieving exocytotic vesicles can be labeled in brain tissue slices and whether their mobility differs to that observed in cell cultures. We labeled astrocytic vesicles and recorded their mobility with two-photon microscopy in hippocampal slices from transgenic mice with fluorescently tagged astrocytes (GFP mice) and in wild-type mice with astrocytes labeled by Fluo4 fluorescence indicator. Glutamatergic vesicles and peptidergic granules were labeled by the anti-vesicular glutamate transporter 1 (vGlut1) and anti-atrial natriuretic peptide (ANP) antibodies, respectively. We report that the vesicle mobility parameters (velocity, maximal displacement and track length) recorded in astrocytes from tissue slices are similar to those reported previously in cultured astrocytes.

  4. Dimethylfumarate inhibits microglial and astrocytic inflammation by suppressing the synthesis of nitric oxide, IL-1β, TNF-α and IL-6 in an in-vitro model of brain inflammation

    Directory of Open Access Journals (Sweden)

    Mrowietz Ulrich

    2010-05-01

    Full Text Available Abstract Background Brain inflammation plays a central role in multiple sclerosis (MS. Dimethylfumarate (DMF, the main ingredient of an oral formulation of fumaric acid esters with proven therapeutic efficacy in psoriasis, has recently been found to ameliorate the course of relapsing-remitting MS. Glial cells are the effector cells of neuroinflammation; however, little is known of the effect of DMF on microglia and astrocytes. The purpose of this study was to use an established in vitro model of brain inflammation to determine if DMF modulates the release of neurotoxic molecules from microglia and astrocytes, thus inhibiting glial inflammation. Methods Primary microglial and astrocytic cell cultures were prepared from cerebral cortices of neonatal rats. The control cells were treated with LPS, an accepted inducer of pro-inflammatory properties in glial cells, and the experimental groups with LPS and DMF in different concentrations. After stimulation/incubation, the generation of nitric oxide (NO in the cell culture supernatants was determined by measuring nitrite accumulation in the medium using Griess reagent. After 6 hours of treatment RT-PCR was used to determine transcription levels of iNOS, IL-1β, IL-6 and TNF-α mRNA in microglial and astrocytic cell cultures initially treated with DMF, followed after 30 min by LPS treatment. Moreover, we investigated possible involvement of the ERK and Nrf-2 transduction pathway in microglia using western blot analysis. Results Pretreatment with DMF decreased synthesis of the proinflammatory mediators iNOS, TNF-α, IL-1β and IL-6 at the RNA level in activated microglia and astrocytes in vitro, associated with a decrease in ERK phosphorylation in microglia. Conclusions Collectively, these results suggest that the neuroprotective effects of DMF may be in part functionally attributable to the compound's ability to inhibit expression of multiple neuroinflammatory mediators in brain of MS patients.

  5. Combined local blood–brain barrier opening and systemic methotrexate for the treatment of brain tumors

    OpenAIRE

    Cooper, Itzik; Last, David; Guez, David; Sharabi, Shirley; Elhaik Goldman, Shirin; Lubitz, Irit; Daniels, Dianne; Salomon,Sharona; Tamar, Gregory; Tamir, Tzur; Mardor, Ronni; Fridkin, Mati; Shechter, Yoram; Mardor, Yael

    2015-01-01

    Despite aggressive therapy, existing treatments offer poor prognosis for glioblastoma multiforme patients, in part due to poor penetration of most drugs across the blood–brain barrier (BBB). We propose a minimal-invasive combined treatment approach consisting of local BBB disruption in the tumor in parallel to systemic drug administration. Local BBB disruption is obtained by convection-enhanced delivery of a novel BBB disruption agent, enabling efficient/targeted delivery of the systemically ...

  6. Brain Imaging with Positron Emission Tomography: Quantification and Biomedical Applications in Alzheimer's Disease and Brain Tumors

    OpenAIRE

    Wardak, Mirwais

    2013-01-01

    Positron emission tomography (PET) is a unique and powerful imaging technique that is used to visualize and quantify various biological processes in living subjects in health and disease. PET imaging can also provide biological information for the assessment of therapies. In this dissertation, we will cover three projects that utilize the quantitative capability of PET for studying two neurological disorders: Alzheimer's disease and brain tumors.One of the goals in PET imaging is to produce...

  7. Safety and efficacy of carmustine (BCNU wafers for metastatic brain tumors

    Directory of Open Access Journals (Sweden)

    Chibawanye I Ene

    2016-01-01

    Conclusions: BCNU wafers are a safe and a potentially efficacious adjunct to surgery and radiation for improving local disease control in metastatic brain tumors. Larger studies, however, are needed to examine overall efficacy and tumor specific efficacy.

  8. Genetic and modifying factors that determine the risk of brain tumors

    DEFF Research Database (Denmark)

    Montelli, Terezinha de Cresci Braga; Peraçoli, Maria Terezinha Serrão; Rogatto, Silvia Regina;

    2011-01-01

    of tumor escape, CNS tumor immunology, immune defects that impair anti-tumor systemic immunity in brain tumor patients and local immuno-suppressive factors within CNS are also reviewed. New hope to treatment perspectives, as dendritic-cell-based vaccines is summarized too. Concluding, it seems well...... established that there is association between brain tumor risk and mutagen sensitivity, which is highly heritable. Primary brain tumors cause depression in systemic host immunity; local immuno-suppressive factors and immunological characteristics of tumor cells may explain the poor prognosis and DNA damages...... responses can alert immune system. However, it is necessary to clarify if individuals with both constitutional defects in immune functions and genetic instability have higher risk of developing brain tumors. Cytogenetic prospective studies and gene copy number variations analysis also must be performed in...

  9. Astrocytes: Orchestrating synaptic plasticity?

    Science.gov (United States)

    De Pittà, M; Brunel, N; Volterra, A

    2016-05-26

    Synaptic plasticity is the capacity of a preexisting connection between two neurons to change in strength as a function of neural activity. Because synaptic plasticity is the major candidate mechanism for learning and memory, the elucidation of its constituting mechanisms is of crucial importance in many aspects of normal and pathological brain function. In particular, a prominent aspect that remains debated is how the plasticity mechanisms, that encompass a broad spectrum of temporal and spatial scales, come to play together in a concerted fashion. Here we review and discuss evidence that pinpoints to a possible non-neuronal, glial candidate for such orchestration: the regulation of synaptic plasticity by astrocytes. PMID:25862587

  10. Metastatic Brain Tumors: A Retrospective Review in East Azarbyjan (Tabriz

    Directory of Open Access Journals (Sweden)

    Zinat Miabi

    2011-02-01

    Full Text Available A set of one hundred and twenty nine patients with known primary malignancy and suspected brain metastasis was reviewed in present study. The patients were selected among patients presented to the MRI section of Imam Khomeini Hospital or a private MRI center in Tabriz (Iran. Primary tumor site, clinical manifestations, number and site of lesions were identified in this patient population. The primary tumor site was breast in 55 patients (42.6%, followed by lung (40.3%, kidney (7.7%, colorectal (4.6%, lymphoma (3.1% and melanoma (1.5%. Most patients were presented with features of increased intracranial pressure (headaches and vomiting, seizures and focal neurologic signs. Single brain metastasis occurred in 16.3% of patients, while multiple lesions accounted for 83.7% of patients. Ninety seven patients had supratentorial metastases (75.2%. Twenty cases (15.5% had metastases in both compartments. Infratentorial lesions were observed only in twelve patients (9.3%.

  11. Is outpatient brain tumor surgery feasible in India?

    Science.gov (United States)

    Turel, Mazda K; Bernstein, Mark

    2016-01-01

    The current trend in all fields of surgery is towards less invasive procedures with shorter hospital stays. The reasons for this change include convenience to patients, optimal resource utilization, and cost saving. Technological advances in neurosurgery, aided by improvements in anesthesia, have resulted in surgery that is faster, simpler, and safer with excellent perioperative recovery. As a result of improved outcomes, some centers are performing brain tumor surgery on an outpatient basis, wherein patients arrive at the hospital the morning of their procedure and leave the hospital the same evening, thus avoiding an overnight stay in the hospital. In addition to the medical benefits of the outpatient procedure, its impact on patient satisfaction is substantial. The economic benefits are extremely favorable for the patient, physician, as well as the hospital. In high volume centers, a day surgery program can exist alongside those for elective and emergency surgeries, providing another pathway for patient care. However, due to skepticism surrounding the medicolegal aspects, and how radical the concept at first sounds, these procedures have not gained widespread popularity. We provide an overview of outpatient brain tumor surgery in the western world, discussing the socioeconomic, medicolegal, and ethical issues related to its adaptability in a developing nation. PMID:27625225

  12. Astrocyte Mitogen Inhibitor Related to Epidermal Growth Factor Receptor

    Science.gov (United States)

    Nieto-Sampedro, Manuel

    1988-06-01

    Epidermal growth factor (EGF) is a well-characterized polypeptide hormone with diverse biological activities, including stimulation of astrocyte division. A soluble astrocyte mitogen inhibitor, immunologically related to the EGF receptor, is present in rat brain. Injury to the brain causes a time-dependent reduction in the levels of this inhibitor and the concomitant appearance of EGF receptor on the astrocyte surface. Intracerebral injection of antibody capable of binding the inhibitor caused the appearance of numerous reactive astrocytes. EGF receptor-related inhibitors may play a key role in the control of glial cell division in both normal and injured brain.

  13. Region-specific astrogliosis in brains of mice heterozygous for mutations in the neurofibromatosis type 1 (Nf1) tumor suppressor

    OpenAIRE

    Rizvi, Tilat A.; Akunuru, Shailaja; de Courten-Myers, Gabrielle; Switzer, Robert C.; Nordlund, Michael L.; Ratner, Nancy

    1999-01-01

    Brains from human neurofibromatosis type 1 (NF1) patients show increased expression of glial fibrillary acidic protein (GFAP), consistent with activation of astrocytes (M.L. Nordlund, T.A. Rizvi, C.I. Brannan, N. Ratner, Neurofibromin expression and astrogliosis in neurofibromatosis (type 1) brains, J. Neuropathol. Exp. Neurology 54 (1995) 588–600). We analyzed brains from transgenic mice in which the Nf1 gene was targeted by homologous recombination. We show here that, in all heterozygous mi...

  14. Fetal brain tumors: Prenatal diagnosis by ultrasound and magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Hérbene; José; Milani; Edward; Araujo; Júnior; Sérgio; Cavalheiro; Patrícia; Soares; Oliveira; Wagner; Jou; Hisaba; Enoch; Quinderé; Sá; Barreto; Maurício; Mendes; Barbosa; Luciano; Marcondes; Nardozza; Antonio; Fernandes; Moron

    2015-01-01

    Congenital central nervous system tumors diagnosed during pregnancy are rare, and often have a poor prognosis. The most frequent type is the teratoma. Use of ultrasound and magnetic resonance image allows the suspicion of brain tumors during pregnancy. However, the definitive diagnosis is only confirmed after birth by histology. The purpose of this mini-review article is to describe the general clinical aspects of intracranial tumors and describe the main fetal brain tumors.

  15. HMGB1 Mediates Endogenous TLR2 Activation and Brain Tumor Regression

    OpenAIRE

    Curtin, James; Liu, Naiyou; Candolfi, Marianela; Xiong, Weidong; Assi, Hikmat; Yagiz, Kader; Edwards, Matthew; Michelsen, Kathrin; Kroeger, Kurt; Liu, Chunyan; Muhammad, AKM Ghulam; Clark, Mary; Arditi, Moshe; Comin-Anduix, Begonya; Ribas, Antoni

    2009-01-01

    Editors' Summary Background. Every year, more than 175,000 people develop a primary brain tumor (a cancer that starts in the brain rather than spreading in from elsewhere). Like all cancers, brain tumors develop when a cell acquires genetic changes that allow it to grow uncontrollably and that change other aspects of its behavior, including the proteins it makes. There are many different types of cells in the brain and, as a result, there are many different types of brain tumors. However, one...

  16. Utility of 99mTc-GHA Brain SPECT in the grading of brain tumors

    International Nuclear Information System (INIS)

    Full text: Brain tumors are of diverse histological types, the most common being derived from glial tissue. The clinical management and prognosis of brain tumor patients is dependent on accurate neuro-pathologic diagnosis and grading. Radiological imaging is not always a good modality for assessing the exact nature and grade of a malignant tumor. Magnetic resonance imaging (MRI) has a very high soft tissue resolution and is helpful in classifying the grade of tumor. Radionuclide imaging techniques that can reveal metabolic activity within tumor cells are very helpful in predicting the degree of malignancy. Usefulness of Tl-201 SPECT and FDG PET studies have been widely reported to evaluate malignant lesions by measuring increased regional glucose metabolism and amino acid uptake. 99mTc-GHA (Glucoheptonate), more or less analogous to 18F-FDG, may show increased glucose metabolism and help in grading tumors. This study was carried out to determine the utility of 99mTc-GHA SPECT for grading cerebral gliomas. Nineteen patients (12M, 7F) aged 22 to 51 years (36.1 ± 8.3) diagnosed clinically and radiologically to have a brain tumor were evaluated with 99mTc-GHA brain SPECT. All the patients had undergone CT/ MRI examination prior to the brain SPECT study. No patient had undergone surgery, radiation therapy or chemotherapy before the imaging studies. Brain SPECT was performed twice, i.e 40 min and 3 hours after intravenous administration of 20 mCi of Tc99m-GHA under a dual head SPECT gamma camera (Ecam, Siemens), with a low energy high-resolution collimator. A total of 128 frames of 30 seconds each, 64 per detector, were acquired in 128 x 128 matrix, with 360-degree rotation in step and shoot mode. Reconstruction of the SPECT data was done using standard software. Abnormal concentration of tracer at the tumor site was compared to normal uptake on the contralateral side, and ratios obtained for early (40 min) and delayed (3 hours) uptake of tracer. Retention ratio (RR), a

  17. Stereotactic interstitial brachytherapy for the treatment of oligodendroglial brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    El Majdoub, Faycal; Neudorfer, Clemens; Maarouf, Mohammad [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); University of Witten/Herdecke, Department of Stereotaxy and Functional Neurosurgery, Center of Neurosurgery, Cologne-Merheim Medical Center (CMMC), Cologne (Germany); Blau, Tobias; Deckert, Martina [University Hospital of Cologne, Department of Neuropathology, Cologne (Germany); Hellmich, Martin [University Hospital of Cologne, Institute of Statistics, Informatics and Epidemiology, Cologne (Germany); Buehrle, Christian [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); Sturm, Volker [University Hospital of Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); University Hospital of Wurzburg, Department of Neurosurgery, Wuerzburg (Germany)

    2015-12-15

    We evaluated the treatment of oligodendroglial brain tumors with interstitial brachytherapy (IBT) using {sup 125}iodine seeds ({sup 125}I) and analyzed prognostic factors. Between January 1991 and December 2010, 63 patients (median age 43.3 years, range 20.8-63.4 years) suffering from oligodendroglial brain tumors were treated with {sup 125}I IBT either as primary, adjuvantly after incomplete resection, or as salvage therapy after tumor recurrence. Possible prognostic factors influencing disease progression and survival were retrospectively investigated. The actuarial 2-, 5-, and 10-year overall and progression-free survival rates after IBT for WHO II tumors were 96.9, 96.9, 89.8 % and 96.9, 93.8, 47.3 %; for WHO III tumors 90.3, 77, 54.9 % and 80.6, 58.4, 45.9 %, respectively. Magnetic resonance imaging demonstrated complete remission in 2 patients, partial remission in 13 patients, stable disease in 17 patients and tumor progression in 31 patients. Median time to progression for WHO II tumors was 87.6 months and for WHO III tumors 27.8 months. Neurological status improved in 10 patients and remained stable in 20 patients, while 9 patients deteriorated. There was no treatment-related mortality. Treatment-related morbidity was transient in 11 patients. WHO II, KPS ≥ 90 %, frontal location, and tumor surface dose > 50 Gy were associated with increased overall survival (p ≤ 0.05). Oligodendroglioma and frontal location were associated with a prolonged progression-free survival (p ≤ 0.05). Our study indicates that IBT achieves local control rates comparable to surgery and radio-/chemotherapy treatment, is minimally invasive, and safe. Due to the low rate of side effects, IBT may represent an attractive option as part of a multimodal treatment schedule, being supplementary to microsurgery or as a salvage therapy after chemotherapy and conventional irradiation. (orig.) [German] Die Behandlung oligodendroglialer Hirntumoren durch die interstitielle Brachytherapie

  18. Using Ferumoxytol-Enhanced MRI to Measure Inflammation in Patients With Brain Tumors or Other Conditions of the CNS

    Science.gov (United States)

    2016-07-08

    Brain Injury; Central Nervous System Degenerative Disorder; Central Nervous System Infectious Disorder; Central Nervous System Vascular Malformation; Hemorrhagic Cerebrovascular Accident; Ischemic Cerebrovascular Accident; Primary Brain Neoplasm; Brain Cancer; Brain Tumors

  19. The Role of Fast Cell Cycle Analysis in Pediatric Brain Tumors.

    Science.gov (United States)

    Alexiou, George A; Vartholomatos, George; Stefanaki, Kalliopi; Lykoudis, Efstathios G; Patereli, Amalia; Tseka, Georgia; Tzoufi, Meropi; Sfakianos, George; Prodromou, Neofytos

    2015-01-01

    Cell cycle analysis by flow cytometry has not been adequately studied in pediatric brain tumors. We investigated the value of a modified rapid (within 6 min) cell cycle analysis protocol for the characterization of malignancy of pediatric brain tumors and for the differentiation of neoplastic from nonneoplastic tissue for possible intraoperative application. We retrospectively studied brain tumor specimens from patients treated at our institute over a 5-year period. All tumor samples were histopathologically verified before flow-cytometric analysis. The histopathological examination of permanent tissue sections was the gold standard. There were 68 brain tumor cases. All tumors had significantly lower G0/G1 and significantly higher S phase and mitosis fractions than normal brain tissue. Furthermore low-grade tumors could be differentiated from high-grade tumors. DNA aneuploidy was detected in 35 tumors. A correlation between S phase fraction and Ki-67 index was found in medulloblastomas and anaplastic ependymomas. Rapid cell cycle analysis by flow cytometry is a promising method for the identification of neoplastic tissue intraoperatively. Low-grade tumors could be differentiated from high-grade tumors. Thus, cell cycle analysis can be a valuable adjunct to the histopathological evaluation of pediatric brain tumors, whereas its intraoperative application warrants further investigation. PMID:26287721

  20. Astrocyte, the star avatar: redefined

    Indian Academy of Sciences (India)

    Pankaj Seth; Nitin Koul

    2008-09-01

    Until recently, the neuroscience community held the belief that glial cells such as astrocytes and oligodendrocytes functioned solely as “support” cells of the brain. In this role, glial cells simply provide physical support and housekeeping functions for the more important cells of the brain, the neurons. However, this view has changed radically in recent years with the discovery of previously unrecognized and surprising functions for this underappreciated cell type. In the past decade or so, emerging evidence has provided new insights into novel glial cell activities such as control of synapse formation and function, communication, cerebrovascular tone regulation, immune regulation and adult neurogenesis. Such advances in knowledge have effectively elevated the role of the astrocyte to one that is more important than previously realized. This review summarizes the past and present knowledge of glial cell functions that has evolved over the years, and has resulted in a new appreciation of astrocytes and their value in studying the neurobiology of human brain cells and their functions. In this review, we highlight recent advances in the role of glial cells in physiology, pathophysiology and, most importantly, in adult neurogenesis and “stemness”, with special emphasis on astrocytes.

  1. Noninvasive detection of temozolomide in brain tumor xenografts by magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Kato, Y.; Holm, David Alberg; Okollie, B.;

    2010-01-01

    Poor drug delivery to brain tumors caused by aberrant tumor vasculature and a partly intact blood-brain barrier (BBB) and blood-brain tumor barrier (BTB) can significantly impair the efficacy of chemotherapy. Determining drug delivery to brain tumors is a challenging problem, and the noninvasive...... detection of drug directly in the tumor can be critically important for accessing, predicting, and eventually improving effectiveness of therapy. In this study, in vivo magnetic resonance spectroscopy (MRS) was used to detect an anticancer agent, temozolomide (TMZ), in vivo in murine xenotransplants of U87...... of similar to 140 mg/kg (450 mg/m(2), well within the maximal clinical dose of 1000 mg/m(2) used in humans) during the course of in vivo MRS experiments. Heteronuclear multiple-quantum coherence (HMQC) MRS of brain tumors was performed before and after i.p. administration of [C-13]TMZ. Dynamic MRI...

  2. Pre Operative Brain Mapping with Functional MRI in Patient with Brain Tumors: Preliminary Report

    Directory of Open Access Journals (Sweden)

    Sina Hooshmand

    2010-05-01

    Full Text Available Background/Objective: Functional Magnetic Resonance Imaging (fMRI plays a significant role in pre-neurosurgical planning at present. FMRI is a possible candidate to replace invasive methods for determination of the language dominant hemisphere and cortical areas associated with language and memory. We used this method to explore language and motor functions in healthy volunteers before creating standard paradigms for Persian language. In this study, we used the standard protocol of language and motor brain mapping in patients harboring brain tumors."nPatients and Methods: Ten patients with brain tumor were included in this study. Each subject performed three to five language related tasks during fMRI scan and also one motor related task. These tasks included; "Word Generation" (WG, "Object Naming" (ON, and "Word Reading" (WR, "Word Production" (WP and "Reverse Word Reading" (RWR. They also performed the thumb apposition task for activating primary sensory-motor areas. Fifteen continuous slices were acquired, and data analysis was carried out using FSL 4.1. After evaluating the individual results, the lateralization index (LI for each subject-task was calculated and the dominant hemisphere for language production was reported. Also localization of critical language areas in the cerebral cortex was performed and the coordinates of epicenter for language production in Broca's area was calculated."nResults: We found that WP, RWR, and WG activate language related areas in the dominant hemisphere robustly in patients with brain tumors and can predict the dominant hemisphere along with eloquent language cortices. However, ON and WR fail to delineate these activation areas optimally. In addition, the results reveal that higher activation intensities are obtained by WP in the frontal lobe including Broca's area, whereas RWR leads to the highest LI among all examined tasks. In patients harboring brain tumors, precise lateralization and

  3. Local production of astrocytes in the cerebral cortex.

    Science.gov (United States)

    Ge, W-P; Jia, J-M

    2016-05-26

    Astrocytes are the largest glial population in the mammalian brain. Astrocytes in the cerebral cortex are reportedly generated from four sources, namely radial glia, progenitors in the subventricular zone (SVZ progenitors), locally proliferating glia, and NG2 glia; it remains an open question, however, as to what extent these four cell types contribute to the substantial increase in astrocytes that occurs postnatally in the cerebral cortex. Here we summarize all possible sources of astrocytes and discuss their roles in this postnatal increase. In particular, we focus on astrocytes derived from local proliferation within the cortex. PMID:26343293

  4. Influence of drugs on gap junctions in glioma cell lines and primary astrocytes in vitro

    Directory of Open Access Journals (Sweden)

    Zahra eMoinfar

    2014-05-01

    Full Text Available Gap junctions (GJs are hemichannels on cell membrane. Once they are intercellulary connected to the neighboring cells, they build a functional syncytium which allows rapid transfer of ions and molecules between cells. This characteristic makes GJs a potential modulator in proliferation, migration and development of the cells. So far, several types of GJs are recognized on different brain cells as well as in glioma. Astrocytes, as one of the major cells that maintain neuronal homeostasis, express different types of GJs that let them communicate with neurons, oligodendrocytes and endothelial cells of the blood brain barrier; however, the main GJ in astrocytes is connexin 43. There are different cerebral diseases in which astrocyte GJs might play a role. Several drugs have been reported to modulate gap junctional communication in the brain which can consequently have beneficial or detrimental effects on the course of treatment in certain diseases. However, the exact cellular mechanism behind those pharmaceutical efficacies on GJs is not well-understood. Accordingly, how specific drugs would affect GJs and what some consequent specific brain diseases would be are the interests of the authors of this chapter. We would focus on pharmaceutical effects on GJs on astrocytes in specific diseases where GJs could possibly play a role including: 1 migraine and a novel therapy for migraine with aura, 2 neuroautoimmune diseases and immunomodulatory drugs in the treatment of demyelinating diseases of the central nervous system such as multiple sclerosis, 3 glioma and antineoplastic and anti-inflammatory agents that are used in treating brain tumors and 4 epilepsy and anticonvulsants that are widely used for seizures therapy. All of the above-mentioned therapeutic categories can possibly affect GJs expression of astrocytes and the role is discussed in the upcoming chapter.

  5. Brain Magnetic Resonance Imaging After High-Dose Chemotherapy and Radiotherapy for Childhood Brain Tumors

    International Nuclear Information System (INIS)

    Purpose: Brain necrosis or other subacute iatrogenic reactions has been recognized as a potential complication of radiotherapy (RT), although the possible synergistic effects of high-dose chemotherapy and RT might have been underestimated. Methods and Materials: We reviewed the clinical and radiologic data of 49 consecutive children with malignant brain tumors treated with high-dose thiotepa and autologous hematopoietic stem cell rescue, preceded or followed by RT. The patients were assessed for neurocognitive tests to identify any correlation with magnetic resonance imaging (MRI) anomalies. Results: Of the 49 children, 18 (6 of 25 with high-grade gliomas and 12 of 24 with primitive neuroectodermal tumors) had abnormal brain MRI findings occurring a median of 8 months (range, 2-39 months) after RT and beginning to regress a median of 13 months (range, 2-26 months) after onset. The most common lesion pattern involved multiple pseudonodular, millimeter-size, T1-weighted unevenly enhancing, and T2-weighted hyperintense foci. Four patients with primitive neuroectodermal tumors also had subdural fluid leaks, with meningeal enhancement over the effusion. One-half of the patients had symptoms relating to the new radiographic findings. The MRI lesion-free survival rate was 74% ± 6% at 1 year and 57% ± 8% at 2 years. The number of marrow ablative courses correlated significantly to the incidence of radiographic anomalies. No significant difference was found in intelligent quotient scores between children with and without radiographic changes. Conclusion: Multiple enhancing cerebral lesions were frequently seen on MRI scans soon after high-dose chemotherapy and RT. Such findings pose a major diagnostic challenge in terms of their differential diagnosis vis-a-vis recurrent tumor. Their correlation with neurocognitive results deserves further investigation

  6. A hybrid neural network analysis of subtle brain volume differences in children surviving brain tumors.

    Science.gov (United States)

    Reddick, W E; Mulhern, R K; Elkin, T D; Glass, J O; Merchant, T E; Langston, J W

    1998-05-01

    In the treatment of children with brain tumors, balancing the efficacy of treatment against commonly observed side effects is difficult because of a lack of quantitative measures of brain damage that can be correlated with the intensity of treatment. We quantitatively assessed volumes of brain parenchyma on magnetic resonance (MR) images using a hybrid combination of the Kohonen self-organizing map for segmentation and a multilayer backpropagation neural network for tissue classification. Initially, we analyzed the relationship between volumetric differences and radiologists' grading of atrophy in 80 subjects. This investigation revealed that brain parenchyma and white matter volumes significantly decreased as atrophy increased, whereas gray matter volumes had no relationship with atrophy. Next, we compared 37 medulloblastoma patients treated with surgery, irradiation, and chemotherapy to 19 patients treated with surgery and irradiation alone. This study demonstrated that, in these patients, chemotherapy had no significant effect on brain parenchyma, white matter, or gray matter volumes. We then investigated volumetric differences due to cranial irradiation in 15 medulloblastoma patients treated with surgery and radiation therapy, and compared these with a group of 15 age-matched patients with low-grade astrocytoma treated with surgery alone. With a minimum follow-up of one year after irradiation, all radiation-treated patients demonstrated significantly reduced white matter volumes, whereas gray matter volumes were relatively unchanged compared with those of age-matched patients treated with surgery alone. These results indicate that reductions in cerebral white matter: 1) are correlated significantly with atrophy; 2) are not related to chemotherapy; and 3) are correlated significantly with irradiation. This hybrid neural network analysis of subtle brain volume differences with magnetic resonance may constitute a direct measure of treatment-induced brain damage

  7. Differential role of tumor necrosis factor receptors in mouse brain inflammatory responses in cryolesion brain injury

    DEFF Research Database (Denmark)

    Quintana, Albert; Giralt, Mercedes; Rojas, Santiago;

    2005-01-01

    Tumor necrosis factor-alpha (TNF-alpha) is one of the mediators dramatically increased after traumatic brain injury that leads to the activation, proliferation, and hypertrophy of mononuclear, phagocytic cells and gliosis. Eventually, TNF-alpha can induce both apoptosis and necrosis via intracell......Tumor necrosis factor-alpha (TNF-alpha) is one of the mediators dramatically increased after traumatic brain injury that leads to the activation, proliferation, and hypertrophy of mononuclear, phagocytic cells and gliosis. Eventually, TNF-alpha can induce both apoptosis and necrosis via...... intracellular signaling. This cytokine exerts its functions via interaction with two receptors: type-1 receptor (TNFR1) and type-2 receptor (TNFR2). In this work, the inflammatory response after a freeze injury (cryolesion) in the cortex was studied in wild-type (WT) animals and in mice lacking TNFR1 (TNFR1 KO...... affected by TNFR1 deficiency. Overall, these results suggest that TNFR1 is involved in the early establishment of the inflammatory response and that its deficiency causes a decreased inflammatory response and tissue damage following brain injury....

  8. Awake brain mapping of cortex and subcortical pathways in brain tumor surgery.

    Science.gov (United States)

    Freyschlag, C F; Duffau, H

    2014-12-01

    Awake surgery is not a new technique: this is a new philosophy. Indeed, in surgery for diffuse gliomas performed in awake patients, the goal is not anymore to remove a "tumor mass" according to oncological boundaries (which in essence do not exist in infiltrating neoplasms), but to resect a part of the brain invaded by a chronic tumoral disease, according to functional limits both at cortical and subcortical levels. Therefore, intraoperative electrical mapping is accepted as the gold standard in order to gain information about the functionality of the underlying tissue when performing neuro-oncological surgery. This review should give the reader an overview of principles and indications of mapping of eloquent cortex and subcortical pathways with practical considerations for cerebral tumors. In gliomas, awake mapping has been demonstrated as increasing the surgical indications in so-called "critical areas" with nonetheless a significant decrease of postoperative morbidity‑while maximizing the extent of resection. Beyond clinical implications, awake surgery represents a unique opportunity to study neural networks underpinning sensorimotor, visuospatial, language, executive and even behavioral functions in humans. This led to propose new models of connectomics, breaking with the localizationist view of brain processing, and opening the window to the concept of neuroplasticity. In summary, awake mapping enables to make a link between surgical neurooncology and cognitive neurosciences, to improve both survival and quality of life of glioma patients. PMID:25418274

  9. Metabolomics and proteomics studies of brain tumors : a chemometric bioinformatics approach

    OpenAIRE

    Mörén, Lina

    2015-01-01

    The WHO classification of brain tumors is based on histological features and the aggressiveness of the tumor is classified from grade I to IV, where grade IV is the most aggressive. Today, the correlation between prognosis and tumor grade is the most important component in tumor classification. High grade gliomas, glioblastomas, are associated with poor prognosis and a median survival of 14 months including all available treatments. Low grade meningiomas, usually benign grade I tumors, are in...

  10. Brain tumor epilepsy: A reappraisal and six remaining issues to be debated.

    OpenAIRE

    Vercueil, Laurent

    2011-01-01

    International audience Epilepsy associated with brain tumors presents with specific features deserving medical attention. Although commonly reported in patients with brain tumor, either as revealing mode or as a remote complication, limited knowledge is available regarding their epidemiology, clinical evolution, surgical outcome, physiopathology and treatment, providing only clues for clinical management. Seizures appear even more threatening for patients and caregivers, providing seizures...

  11. Automatic Brain Tumor Detection in T2-weighted Magnetic Resonance Images

    Czech Academy of Sciences Publication Activity Database

    Dvořák, Pavel; Kropatsch, W.G.; Bartušek, Karel

    2013-01-01

    Roč. 13, č. 5 (2013), s. 223-230. ISSN 1335-8871 R&D Projects: GA ČR GAP102/12/1104; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : Brain tumor * Brain tumor detection * Symmetry analysis Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.162, year: 2013

  12. Cognitive deficits in long-term survivors of childhood brain tumors: Identification of predictive factors

    DEFF Research Database (Denmark)

    Reimers, Tonny Solveig; Ehrenfels, Susanne; Mortensen, Erik Lykke; Schmiegelow, Marianne; Sønderkaer, Signe; Carstensen, Mads Henrik; Schmiegelow, Kjeld; Müller, Jørn

    2003-01-01

    To describe cognitive function and to evaluate the association between potentially predictive factors and cognitive outcome in an unselected population of survivors of childhood brain tumors.......To describe cognitive function and to evaluate the association between potentially predictive factors and cognitive outcome in an unselected population of survivors of childhood brain tumors....

  13. Brain tumors in children and adolescents and exposure to animals and farm life

    DEFF Research Database (Denmark)

    Christensen, Jeppe Schultz; Mortensen, Laust Hvas; Röösli, Martin; Feychting, Maria; Tynes, Tore; Andersen, Tina Veje; Schmidt, Lisbeth Samsø; Poulsen, Aslak Harbo; Aydin, Denis; Kuehni, Claudia E; Prochazka, Michaela; Lannering, Birgitta; Klaeboe, Lars; Eggen, Tone; Schüz, Joachim

    2012-01-01

    The etiology of brain tumors in children and adolescents is largely unknown, and very few environmental risk factors have been identified. The aim of this study was to examine the relationship between pre- or postnatal animal contacts or farm exposures and the risk of childhood brain tumors (CBTs...

  14. New therapeutic approach for brain tumors: Intranasal delivery of telomerase inhibitor GRN163.

    Science.gov (United States)

    Hashizume, Rintaro; Ozawa, Tomoko; Gryaznov, Sergei M; Bollen, Andrew W; Lamborn, Kathleen R; Frey, William H; Deen, Dennis F

    2008-04-01

    The blood-brain barrier is a substantial obstacle for delivering anticancer agents to brain tumors, and new strategies for bypassing it are greatly needed for brain-tumor therapy. Intranasal delivery provides a practical, noninvasive method for delivering therapeutic agents to the brain and could provide an alternative to intravenous injection and convection-enhanced delivery. We treated rats bearing intracerebral human tumor xenografts intranasally with GRN163, an oligonucleotide N3'-->P5'thio-phosphoramidate telomerase inhibitor. 3'-Fuorescein isothiocyanate (FITC)-labeled GRN163 was administered intranasally every 2 min as 6 microl drops into alternating sides of the nasal cavity over 22 min. FITC-labeled GRN163 was present in tumor cells at all time points studied, and accumulation of GRN163 peaked at 4 h after delivery. Moreover, GRN163 delivered intranasally, daily for 12 days, significantly prolonged the median survival from 35 days in the control group to 75.5 days in the GRN163-treated group. Thus, intranasal delivery of GRN163 readily bypassed the blood-brain barrier, exhibited favorable tumor uptake, and inhibited tumor growth, leading to a prolonged lifespan for treated rats compared to controls. This delivery approach appears to kill tumor cells selectively, and no toxic effects were noted in normal brain tissue. These data support further development of intranasal delivery of tumor-specific therapeutic agents for brain tumor patients. PMID:18287341

  15. Isolation and Characterization of Ischemia-Derived Astrocytes (IDAs) with Ability to Transactivate Quiescent Astrocytes

    Science.gov (United States)

    Villarreal, Alejandro; Rosciszewski, Gerardo; Murta, Veronica; Cadena, Vanesa; Usach, Vanina; Dodes-Traian, Martin M.; Setton-Avruj, Patricia; Barbeito, Luis H.; Ramos, Alberto J.

    2016-01-01

    Reactive gliosis involving activation and proliferation of astrocytes and microglia, is a widespread but largely complex and graded glial response to brain injury. Astroglial population has a previously underestimated high heterogeneity with cells differing in their morphology, gene expression profile, and response to injury. Here, we identified a subset of reactive astrocytes isolated from brain focal ischemic lesions that show several atypical characteristics. Ischemia-derived astrocytes (IDAs) were isolated from early ischemic penumbra and core. IDA did not originate from myeloid precursors, but rather from pre-existing local progenitors. Isolated IDA markedly differ from primary astrocytes, as they proliferate in vitro with high cell division rate, show increased migratory ability, have reduced replicative senescence and grow in the presence of macrophages within the limits imposed by the glial scar. Remarkably, IDA produce a conditioned medium that strongly induced activation on quiescent primary astrocytes and potentiated the neuronal death triggered by oxygen-glucose deprivation. When re-implanted into normal rat brains, eGFP-IDA migrated around the injection site and induced focal reactive gliosis. Inhibition of gamma secretases or culture on quiescent primary astrocytes monolayers facilitated IDA differentiation to astrocytes. We propose that IDA represent an undifferentiated, pro-inflammatory, highly replicative and migratory astroglial subtype emerging from the ischemic microenvironment that may contribute to the expansion of reactive gliosis. Main Points: Ischemia-derived astrocytes (IDA) were isolated from brain ischemic tissue IDA show reduced replicative senescence, increased cell division and spontaneous migration IDA potentiate death of oxygen-glucose deprived cortical neurons IDA propagate reactive gliosis on quiescent astrocytes in vitro and in vivo Inhibition of gamma secretases facilitates IDA differentiation to astrocytes PMID:27313509

  16. Expression of Astrocytic Type 2 Angiotensin Receptor in Central Nervous System Inflammation Correlates With Blood-Brain Barrier Breakdown

    DEFF Research Database (Denmark)

    Füchtbauer, Laila; Toft-Hansen, Henrik; Khorooshi, Reza;

    2010-01-01

    The blood-brain barrier (BBB), a complex of endothelial and glial barriers, controls passage of cells and solutes between the blood and central nervous system (CNS). Blood-brain barrier breakdown refers to entry of cells and/or solutes. We were interested whether the renin-angiotensin system is...... involved during BBB breakdown. We studied the type 2 angiotensin receptor AT(2) because of its suggested neuroprotective role. Two models of brain inflammation were used to distinguish solute versus cellular barrier functions. Both leukocytes and horseradish peroxidase (HRP) accumulated in the perivascular...

  17. 3-D in vivo brain tumor geometry study by scaling analysis

    Science.gov (United States)

    Torres Hoyos, F.; Martín-Landrove, M.

    2012-02-01

    A new method, based on scaling analysis, is used to calculate fractal dimension and local roughness exponents to characterize in vivo 3-D tumor growth in the brain. Image acquisition was made according to the standard protocol used for brain radiotherapy and radiosurgery, i.e., axial, coronal and sagittal magnetic resonance T1-weighted images, and comprising the brain volume for image registration. Image segmentation was performed by the application of the k-means procedure upon contrasted images. We analyzed glioblastomas, astrocytomas, metastases and benign brain tumors. The results show significant variations of the parameters depending on the tumor stage and histological origin.

  18. Study of Inter- and Intra-fraction Motion in Brain Tumor Patients Undergoing VMAT Treatment

    International Nuclear Information System (INIS)

    Conforming dose to the tumor and sparing normal tissue can be challenging for brain tumors with complex shapes in close proximity to critical structures. The goal of this study was to evaluate the inter- and intra-fraction motion in brain tumor patients undergoing volumetric modulated arc therapy (VMAT). The image matching software was found to be very sensitive to the choice of the region of matching. It is recommended to use the same region of interest for comparing the image sets and perform the automatic matching based on bony landmarks in brain tumor cases. (Author)

  19. Neural Network Based Augmented Reality for Detection of Brain Tumor

    Directory of Open Access Journals (Sweden)

    P.Mithun

    2013-04-01

    Full Text Available The development in technology opened the door of fiction and reached reality. Major medical applications deals on robot-assisted surgery and image guided surgery. Because of this, substantial research is going on to implement Augmented Reality (AR in instruments which incorporate the surgeon’s intuitive capabilities. Augmented reality is the grouping of virtual entity or 3D stuffs which are overlapped on live camera feed information. The decisive aim of augmented reality is to enhancing the virtual video and a 3D object onto a real world on which it will raise the person’s conceptual understanding of the subject. In this paper we described a solution for initial prediction of tumour cells in MRI images of human brain using image processing technique the output of which will be the 3D slicedimage of the human brain. The sliced image is then virtually embedded on the top of human head during the time of surgery so that the surgeon can exactly locate the spot to be operated. Before augmenting the 3D sliced image Artificial neural network is used to select the appropriate image that contains tumor automatically in order to make the system more efficient.

  20. Towards the use of HIFU, in Conjunction with Surgery, in the Treatment of Malignant Brain Tumors

    Science.gov (United States)

    Dahl, Elizabeth; Nguyen, Lisa T.; Sparks, Rachel E.; Brayman, Andy A.; Olios, Ryan J.; Silbergeld, Daniel L.; Vaezy, Sarah; Mourad, Pierre D.

    2006-05-01

    The first medical response to the presence of a brain tumor is often its resection, both to alleviate mass effect, and to obtain tissue for diagnosis, itself necessary for guiding adjunctive therapy. Malignant brain tumors typically recur at the tumor resection margin. Most current chemotherapy and radiotherapy strategies target local recurrence with limited success. Here we review a new strategy for delivering chemotherapeutics for brain tumor recurrence. It uses intra-operative high-intensity focused ultrasound (HIFU) to transiently open the blood-brain barrier (BBB) over a significantly large volume of brain at and near the resection margin to enhance the subsequent delivery of systemically delivered chemotherapeutic agents into the region of tumor recurrence.