Neoplasms of the brain and spinal cord derived from glial cells which vary from histologically benign forms to highly anaplastic and malignant tumors. Fibrillary astrocytomas are the most common type and may be classified in order of increasing malignancy (grades I through IV). In the first two decades of life, astrocytomas tend to originate in the cerebellar hemispheres; in adults, they most frequently arise in the cerebrum and frequently undergo malignant transformation. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2013-7; Holland et al., Cancer Medicine, 3d ed, p1082)
Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.
Benign and malignant tumors of the HYPOTHALAMUS. Pilocytic astrocytomas and hamartomas are relatively frequent histologic types. Neoplasms of the hypothalamus frequently originate from adjacent structures, including the OPTIC CHIASM, optic nerve (see OPTIC NERVE NEOPLASMS), and pituitary gland (see PITUITARY NEOPLASMS). Relatively frequent clinical manifestations include visual loss, developmental delay, macrocephaly, and precocious puberty. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2051)
A malignant form of astrocytoma histologically characterized by pleomorphism of cells, nuclear atypia, microhemorrhage, and necrosis. They may arise in any region of the central nervous system, with a predilection for the cerebral hemispheres, basal ganglia, and commissural pathways. Clinical presentation most frequently occurs in the fifth or sixth decade of life with focal neurologic signs or seizures.
Benign and malignant neoplasms that arise from the optic nerve or its sheath. OPTIC NERVE GLIOMA is the most common histologic type. Optic nerve neoplasms tend to cause unilateral visual loss and an afferent pupillary defect and may spread via neural pathways to the brain.
Benign and malignant central nervous system neoplasms derived from glial cells (i.e., astrocytes, oligodendrocytes, and ependymocytes). Astrocytes may give rise to astrocytomas (ASTROCYTOMA) or glioblastoma multiforme (see GLIOBLASTOMA). Oligodendrocytes give rise to oligodendrogliomas (OLIGODENDROGLIOMA) and ependymocytes may undergo transformation to become EPENDYMOMA; CHOROID PLEXUS NEOPLASMS; or colloid cysts of the third ventricle. (From Escourolle et al., Manual of Basic Neuropathology, 2nd ed, p21)
Primary and metastatic (secondary) tumors of the brain located above the tentorium cerebelli, a fold of dura mater separating the CEREBELLUM and BRAIN STEM from the cerebral hemispheres and DIENCEPHALON (i.e., THALAMUS and HYPOTHALAMUS and related structures). In adults, primary neoplasms tend to arise in the supratentorial compartment, whereas in children they occur more frequently in the infratentorial space. Clinical manifestations vary with the location of the lesion, but SEIZURES; APHASIA; HEMIANOPSIA; hemiparesis; and sensory deficits are relatively common features. Metastatic supratentorial neoplasms are frequently multiple at the time of presentation.
A relatively slow-growing glioma that is derived from oligodendrocytes and tends to occur in the cerebral hemispheres, thalamus, or lateral ventricle. They may present at any age, but are most frequent in the third to fifth decades, with an earlier incidence peak in the first decade. Histologically, these tumors are encapsulated, relatively avascular, and tend to form cysts and microcalcifications. Neoplastic cells tend to have small round nuclei surrounded by unstained nuclei. The tumors may vary from well-differentiated to highly anaplastic forms. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2052; Adams et al., Principles of Neurology, 6th ed, p655)
Benign and malignant neoplasms which occur within the substance of the spinal cord (intramedullary neoplasms) or in the space between the dura and spinal cord (intradural extramedullary neoplasms). The majority of intramedullary spinal tumors are primary CNS neoplasms including ASTROCYTOMA; EPENDYMOMA; and LIPOMA. Intramedullary neoplasms are often associated with SYRINGOMYELIA. The most frequent histologic types of intradural-extramedullary tumors are MENINGIOMA and NEUROFIBROMA.
A class of large neuroglial (macroglial) cells in the central nervous system - the largest and most numerous neuroglial cells in the brain and spinal cord. Astrocytes (from "star" cells) are irregularly shaped with many long processes, including those with "end feet" which form the glial (limiting) membrane and directly and indirectly contribute to the BLOOD-BRAIN BARRIER. They regulate the extracellular ionic and chemical environment, and "reactive astrocytes" (along with MICROGLIA) respond to injury.
Loss of structural differentiation and useful function of neoplastic cells.
Primary or metastatic neoplasms of the CEREBELLUM. Tumors in this location frequently present with ATAXIA or signs of INTRACRANIAL HYPERTENSION due to obstruction of the fourth ventricle. Common primary cerebellar tumors include fibrillary ASTROCYTOMA and cerebellar HEMANGIOBLASTOMA. The cerebellum is a relatively common site for tumor metastases from the lung, breast, and other distant organs. (From Okazaki & Scheithauer, Atlas of Neuropathology, 1988, p86 and p141)
Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.
Glioma derived from EPENDYMOGLIAL CELLS that tend to present as malignant intracranial tumors in children and as benign intraspinal neoplasms in adults. It may arise from any level of the ventricular system or central canal of the spinal cord. Intracranial ependymomas most frequently originate in the FOURTH VENTRICLE and histologically are densely cellular tumors which may contain ependymal tubules and perivascular pseudorosettes. Spinal ependymomas are usually benign papillary or myxopapillary tumors. (From DeVita et al., Principles and Practice of Oncology, 5th ed, p2018; Escourolle et al., Manual of Basic Neuropathology, 2nd ed, pp28-9)
Benign and malignant neoplastic processes that arise from or secondarily involve the brain, spinal cord, or meninges.
Antineoplastic agent especially effective against malignant brain tumors. The resistance which brain tumor cells acquire to the initial effectiveness of this drug can be partially overcome by the simultaneous use of membrane-modifying agents such as reserpine, calcium antagonists such as nicardipine or verapamil, or the calmodulin inhibitor, trifluoperazine. The drug has also been used in combination with other antineoplastic agents or with radiotherapy for the treatment of various neoplasms.
Benign and malignant intra-axial tumors of the MESENCEPHALON; PONS; or MEDULLA OBLONGATA of the BRAIN STEM. Primary and metastatic neoplasms may occur in this location. Clinical features include ATAXIA, cranial neuropathies (see CRANIAL NERVE DISEASES), NAUSEA, hemiparesis (see HEMIPLEGIA), and quadriparesis. Primary brain stem neoplasms are more frequent in children. Histologic subtypes include GLIOMA; HEMANGIOBLASTOMA; GANGLIOGLIOMA; and EPENDYMOMA.
An intermediate filament protein found only in glial cells or cells of glial origin. MW 51,000.
GENES with ALLELES that affect the PHENOTYPE associated with a nonallelic gene.
The X-shaped structure formed by the meeting of the two optic nerves. At the optic chiasm the fibers from the medial part of each retina cross to project to the other side of the brain while the lateral retinal fibers continue on the same side. As a result each half of the brain receives information about the contralateral visual field from both eyes.
Rare indolent tumors comprised of neoplastic glial and neuronal cells which occur primarily in children and young adults. Benign lesions tend to be associated with long survival unless the tumor degenerates into a histologically malignant form. They tend to occur in the optic nerve and white matter of the brain and spinal cord.
An antineoplastic agent. It has significant activity against melanomas. (from Martindale, The Extra Pharmacopoeia, 31st ed, p564)
Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.
Benign and malignant neoplastic processes that arise from or secondarily involve the meningeal coverings of the brain and spinal cord.
A relatively common neoplasm of the CENTRAL NERVOUS SYSTEM that arises from arachnoidal cells. The majority are well differentiated vascular tumors which grow slowly and have a low potential to be invasive, although malignant subtypes occur. Meningiomas have a predilection to arise from the parasagittal region, cerebral convexity, sphenoidal ridge, olfactory groove, and SPINAL CANAL. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2056-7)
Benign and malignant neoplastic processes arising from or involving components of the central, peripheral, and autonomic nervous systems, cranial nerves, and meninges. Included in this category are primary and metastatic nervous system neoplasms.
Disorders of the centrally located thalamus, which integrates a wide range of cortical and subcortical information. Manifestations include sensory loss, MOVEMENT DISORDERS; ATAXIA, pain syndromes, visual disorders, a variety of neuropsychological conditions, and COMA. Relatively common etiologies include CEREBROVASCULAR DISORDERS; CRANIOCEREBRAL TRAUMA; BRAIN NEOPLASMS; BRAIN HYPOXIA; INTRACRANIAL HEMORRHAGES; and infectious processes.
The front portion of the HYPOTHALAMUS separated into the preoptic region and the supraoptic region. The preoptic region is made up of the periventricular GRAY MATTER of the rostral portion of the THIRD VENTRICLE and contains the preoptic ventricular nucleus and the medial preoptic nucleus. The supraoptic region contains the PARAVENTRICULAR HYPOTHALAMIC NUCLEUS, the SUPRAOPTIC NUCLEUS, the ANTERIOR HYPOTHALAMIC NUCLEUS, and the SUPRACHIASMATIC NUCLEUS.
A specific pair of GROUP C CHROMOSOMES of the human chromosome classification.
Methods which attempt to express in replicable terms the level of CELL DIFFERENTIATION in neoplasms as increasing ANAPLASIA correlates with the aggressiveness of the neoplasm.
A class of drugs that differs from other alkylating agents used clinically in that they are monofunctional and thus unable to cross-link cellular macromolecules. Among their common properties are a requirement for metabolic activation to intermediates with antitumor efficacy and the presence in their chemical structures of N-methyl groups, that after metabolism, can covalently modify cellular DNA. The precise mechanisms by which each of these drugs acts to kill tumor cells are not completely understood. (From AMA, Drug Evaluations Annual, 1994, p2026)
Autosomal dominant neurocutaneous syndrome classically characterized by MENTAL RETARDATION; EPILEPSY; and skin lesions (e.g., adenoma sebaceum and hypomelanotic macules). There is, however, considerable heterogeneity in the neurologic manifestations. It is also associated with cortical tuber and HAMARTOMAS formation throughout the body, especially the heart, kidneys, and eyes. Mutations in two loci TSC1 and TSC2 that encode hamartin and tuberin, respectively, are associated with the disease.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)

Expression and tissue localization of membrane-type 1, 2, and 3 matrix metalloproteinases in human astrocytic tumors. (1/1796)

Three different membrane-type matrix metalloproteinases (MT1-, MT2-, and MT3-MMPs) are known to activate in vitro the zymogen of MMP-2 (pro-MMP-2, progelatinase A), which is one of the key MMPs in invasion and metastasis of various cancers. In the present study, we have examined production and activation of pro-MMP-2, expression of MT1-, MT2-, and MT3-MMPs and their correlation with pro-MMP-2 activation, and localization of MMP-2, MT1-MMP, and MT2-MMP in human astrocytic tumors. The sandwich enzyme immunoassay demonstrates that the production levels of pro-MMP-2 in the anaplastic astrocytomas and glioblastomas are significantly higher than that in the low-grade astrocytomas (P<0.05 and P<0.01, respectively), metastatic brain tumors (P<0.05), or normal brains (P<0.01). Gelatin zymography indicates that the pro-MMP-2 activation ratio is significantly higher in the glioblastomas than in other astrocytic tumors (P<0.01), metastatic brain tumors (P<0.01), and normal brains (P<0.01). The quantitative reverse transcription polymerase chain reaction analyses demonstrate that MT1-MMP and MT2-MMP are expressed predominantly in glioblastoma tissues (17/17 and 12/17 cases, respectively), and their expression levels increase significantly as tumor grade increases. MT3-MMP is detectable in both astrocytic tumor and normal brain tissues, but the mean expression level is approximately 50-fold lower compared with that of MT1-MMP and MT2-MMP in the glioblastomas. The activation ratio of pro-MMP-2 correlates directly with the expression levels of MT1-MMP and MT2-MMP but not MT3-MMP. In situ hybridization indicates that neoplastic astrocytes express MT1-MMP and MT2-MMP in the glioblastoma tissues (5/5 cases and 5/5 cases, respectively). Immunohistochemically, MT1-MMP and MT2-MMP are localized to the neoplastic astrocytes in glioblastoma samples (17/17 cases and 12/17 cases, respectively), which are also positive for MMP-2. In situ zymography shows gelatinolytic activity in the glioblastoma tissues but not in the normal brain tissues. These results suggest that both MT1-MMP and MT2-MMP play a key role in the activation of pro-MMP-2 in the human malignant astrocytic tumors and that the gelatinolytic activity is involved in the astrocytic tumor invasion.  (+info)

Early induction of angiogenetic signals in gliomas of GFAP-v-src transgenic mice. (2/1796)

Angiogenesis is a prerequisite for solid tumor growth. Glioblastoma multiforme, the most common malignant brain tumor, is characterized by extensive vascular proliferation. We previously showed that transgenic mice expressing a GFAP-v-src fusion gene in astrocytes develop low-grade astrocytomas that progressively evolve into hypervascularized glioblastomas. Here, we examined whether tumor progression triggers angiogenetic signals. We found abundant transcription of vascular endothelial growth factor (VEGF) in neoplastic astrocytes at surprisingly early stages of tumorigenesis. VEGF and v-src expression patterns were not identical, suggesting that VEGF activation was not only dependent on v-src. Late-stage gliomas showed perinecrotic VEGF up-regulation similarly to human glioblastoma. Expression patterns of the endothelial angiogenic receptors flt-1, flk-1, tie-1, and tie-2 were similar to those described in human gliomas, but flt-1 was expressed also in neoplastic astrocytes, suggesting an autocrine role in tumor growth. In crossbreeding experiments, hemizygous ablation of the tumor suppressor genes Rb and p53 had no significant effect on the expression of VEGF, flt-1, flk-1, tie-1, and tie-2. Therefore, expression of angiogenic signals is an early event during progression of GFAP-v-src tumors and precedes hypervascularization. Given the close similarities in the progression pattern between GFAP-v-src and human gliomas, the present results suggest that these mice may provide a useful tool for antiangiogenic therapy research.  (+info)

Clinical importance of c-Met protein expression in high grade astrocytic tumors. (3/1796)

The clinical importance of the expression of c-Met protein, the receptor of hepatocyte growth factor/scatter factor, was evaluated in neuroepithelial tissue tumors. c-Met immunohistochemistry was performed using the streptavidin-biotin-peroxidase complex method with anti-c-Met polyclonal antibody. Specimens were classified as c-Met negative (< 30%) or c-Met positive (> or = 30%) according to the proportion of immunopositive cells under microscopic examination. All c-Met-positive cases occurred in high grade astrocytic tumors, not in other neuroepithelial tissue tumors. Most c-Met-positive astrocytic tumors were classified histologically as high grade tumors. Epidermal growth factor-receptor (EGFR) and MIB-1 immunohistochemistry were also performed for high grade astrocytic tumors. Survival analysis was performed for patients with these tumors with variables including c-Met positivity, EGFR positivity, and MIB-1 labeling index. Positivity of c-Met was independent from EGFR positivity and MIB-1 labeling index, and the c-Met-positive group showed a significant shorter survival (p < 0.05). c-Met immunopositivity may be a parameter of biological aggressiveness in high grade astrocytic tumors. Examination of c-Met expression in astrocytic tumors provides significant clinical information, especially as a prognostic factor.  (+info)

Secondary glioblastoma remarkably reduced by steroid administration after anaplastic transformation from gliomatosis cerebri--case report. (4/1796)

A 45-year-old female presented with gliomatosis cerebri manifesting as hemiballismus-like involuntary movement in the arm, motor weakness in the leg, and hypesthesia in her left side. Computed tomography showed only diffuse swelling of the right cerebral hemisphere, but T2-weighted magnetic resonance imaging revealed a diffuse lesion spreading from the right thalamus to the temporal, parietal, and occipital lobes on the same side. No abnormal enhancement was recognized. Cerebral angiography showed no specific finding. A right occipital lobectomy was performed to confirm the diagnosis of gliomatosis cerebri. Anaplastic transformation was recognized 5 months later. The disease did not resolve with radiation or interferon administration, but steroid therapy achieved remarkably effective tumor regression. The patient died due to pneumonia. Autopsy showed the features of diffuse glioblastoma. Steroid therapy may be an effective treatment for gliomatosis cerebri before the terminal stage.  (+info)

Requirements for measles virus induction of RANTES chemokine in human astrocytoma-derived U373 cells. (5/1796)

Interferons and chemokines play a critical role in regulating the host response to viral infection. Measles virus, a member of the Paramyxoviridae family, induces RANTES expression by astrocytes. We have examined the mechanism of this induction in U373 cells derived from a human astrocytoma. RANTES was induced in a dose- and time-dependent manner by measles virus infection. Inhibition of receptor binding by the anti-CD46 antibody TRA-2.10 and of virus-membrane fusion by the tripeptide X-Phe-Phe-Gly reduced RANTES expression. Formalin-inactivated virus, which can bind but not fuse, and extensively UV-irradiated virus, which can bind and fuse, were both ineffective. Therefore, virus binding to the cellular receptor CD46 and subsequent membrane fusion were necessary, but not sufficient, to induce RANTES. UV irradiation of virus for less than 10 min proportionally inhibited viral transcription and RANTES expression. RANTES induction was decreased in infected cells treated with ribavirin, which inhibits measles virus transcription. However, RANTES mRNA was superinduced by measles virus in the presence of cycloheximide. These data suggest that partial transcription of the viral genome is sufficient and necessary for RANTES induction, whereas viral protein synthesis and replication are not required. This hypothesis was supported by the fact that RANTES was induced through transient expression of the measles virus nucleocapsid gene but not by measles genes encoding P or L proteins or by leader RNA in A549 cells. Thus, transcription of specific portions of measles virus RNA, such as the nucleocapsid gene, appears able to generate the specific signaling required to induce RANTES gene expression.  (+info)

Persistent infection of human oligodendrocytic and neuroglial cell lines by human coronavirus 229E. (6/1796)

Human coronaviruses (HuCV) cause common colds. Previous reports suggest that these infectious agents may be neurotropic in humans, as they are for some mammals. With the long-term aim of providing experimental evidence for the neurotropism of HuCV and the establishment of persistent infections in the nervous system, we have evaluated the susceptibility of various human neural cell lines to acute and persistent infection by HuCV-229E. Viral antigen, infectious virus progeny and viral RNA were monitored during both acute and persistent infections. The astrocytoma cell lines U-87 MG, U-373 MG, and GL-15, as well as neuroblastoma SK-N-SH, neuroglioma H4, and oligodendrocytic MO3.13 cell lines, were all susceptible to an acute infection by HuCV-229E. The CHME-5 immortalized fetal microglial cell line was not susceptible to infection by this virus. The MO3.13 and H4 cell lines also sustained a persistent viral infection, as monitored by detection of viral antigen and infectious virus progeny. Sequencing of the S1 gene from viral RNA after approximately 130 days of infection showed two point mutations, suggesting amino acid changes during persistent infection of MO3.13 cells but none for H4 cells. Thus, persistent in vitro infection did not generate important changes in the S1 portion of the viral spike protein, which was shown for murine coronaviruses to bear hypervariable domains and to interact with cellular receptor. These results are consistent with the potential persistence of HuCV-229E in cells of the human nervous system, such as oligodendrocytes and possibly neurons, and the virus's apparent genomic stability.  (+info)

Simultaneous alterations of retinoblastoma and p53 protein expression in astrocytic tumors. (7/1796)

The genetic alterations frequently involved in glial malignancies are in the tumor suppressor genes, Rb and p53. An altered Rb expression or p53 overexpression is thought to indicate defective tumor suppression and subsequently more aggressive tumors. Therefore, to assess the alterations in the conjoint expression of Rb and p53 proteins in formalin fixed paraffin embedded sections, 64 astrocytic tumors were studied (16 astrocytomas,7 gemistocytic astrocytomas, 19 anaplastic astrocytomas and 22 glioblastomas) using the avidin biotin immunoperoxidase technique. Fifty two cases (81.25%) were found to be positive for p53 protein. Seventeen of these showed aberrant heterogenous staining for pRb, of which 7 were glioblastomas. Only one case of astrocytoma showed aberrant expression of both p53 and Rb. Thus, of the 64 tumors, simultaneous aberrant expression of both p53 and Rb was seen in 21.9% of cases. This was more commonly observed among glioblastoma cases (7/22). No statistical difference was found between the survival rate of heterogenous pRb and p53 positivity in different grades of tumors. In glioblastomas, the survival rate appeared to be less in patients expressing heterogenous pRb, but this was not statistically significant. These results lead us to suspect that p53 and pRb pathways are inactivated, either through mutation or as part of the neoplastic process in astrocytic tumors.  (+info)

Procarbazine and high-dose tamoxifen as a second-line regimen in recurrent high-grade gliomas: a phase II study. (8/1796)

PURPOSE: A phase II study was conducted in patients with high-grade gliomas that recurred after surgery plus radiotherapy and a first-line nitrosourea-based regimen. Our aim was to investigate the efficacy of procarbazine (PCB) combined with high-dose tamoxifen in relation to tumor control, toxicity, and time to progression (TTP). PATIENTS AND METHODS: Fifty-three patients were treated with procarbazine in repeated 30-day courses at 100 mg/m2/d plus tamoxifen 100 mg/d, with a 30-day interval between courses. Thirty-four patients had been pretreated with a first-line nitrosourea-based chemotherapy regimen (group A), and 19 patients had also been pretreated with a second-line chemotherapy regimen consisting of carboplatin and teniposide (group B). Twenty-one of the patients had also been procarbazine pretreated, whereas the remaining 32 patients were not procarbazine pretreated. RESULTS: The response was assessed in 51 patients, 28 of whom had glioblastoma multiforme (GBM) and 23 of whom had anaplastic astrocytoma (AA). There were two complete responses (CR) (4%) and 13 partial responses (PR) (25.5%). The overall response rate (CR + PR) was 29.5% (SE, 6.4; 95% confidence interval [CI], 23 to 35.8). Seventeen patients (32%) had stable disease (SE, 6.2; 95% CI, 21 to 33.6). The median TTP was 13 weeks for patients with GBM and 33 weeks for patients with AA (P = .006). The median survival time (MST) was 27 weeks for patients with GBM and 57 weeks for those with AA (P = .006). CONCLUSION: Combined PCB and tamoxifen as a second-line regimen gave a reasonably high response rate in patients with heavily pretreated high-grade gliomas. However, although it resulted in an improvement in the patients' quality of life and/or performance status, it was not followed by an increased TTP or MST.  (+info)

Astrocytoma is a type of brain tumor that arises from astrocytes, which are star-shaped glial cells in the brain. These tumors can occur in various parts of the brain and can have different grades of malignancy, ranging from low-grade (I or II) to high-grade (III or IV). Low-grade astrocytomas tend to grow slowly and may not cause any symptoms for a long time, while high-grade astrocytomas are more aggressive and can grow quickly, causing neurological problems.

Symptoms of astrocytoma depend on the location and size of the tumor but may include headaches, seizures, weakness or numbness in the limbs, difficulty speaking or swallowing, changes in vision or behavior, and memory loss. Treatment options for astrocytomas include surgery, radiation therapy, chemotherapy, or a combination of these approaches. The prognosis for astrocytoma varies widely depending on the grade and location of the tumor, as well as the age and overall health of the patient.

Brain neoplasms, also known as brain tumors, are abnormal growths of cells within the brain. These growths can be benign (non-cancerous) or malignant (cancerous). Benign brain tumors typically grow slowly and do not spread to other parts of the body. However, they can still cause serious problems if they press on sensitive areas of the brain. Malignant brain tumors, on the other hand, are cancerous and can grow quickly, invading surrounding brain tissue and spreading to other parts of the brain or spinal cord.

Brain neoplasms can arise from various types of cells within the brain, including glial cells (which provide support and insulation for nerve cells), neurons (nerve cells that transmit signals in the brain), and meninges (the membranes that cover the brain and spinal cord). They can also result from the spread of cancer cells from other parts of the body, known as metastatic brain tumors.

Symptoms of brain neoplasms may vary depending on their size, location, and growth rate. Common symptoms include headaches, seizures, weakness or paralysis in the limbs, difficulty with balance and coordination, changes in speech or vision, confusion, memory loss, and changes in behavior or personality.

Treatment for brain neoplasms depends on several factors, including the type, size, location, and grade of the tumor, as well as the patient's age and overall health. Treatment options may include surgery, radiation therapy, chemotherapy, targeted therapy, or a combination of these approaches. Regular follow-up care is essential to monitor for recurrence and manage any long-term effects of treatment.

Hypothalamic neoplasms refer to tumors that originate in the hypothalamus, a small region of the brain that is located at the base of the brain and forms part of the limbic system. The hypothalamus plays a critical role in regulating many bodily functions, including hormone release, temperature regulation, hunger, thirst, sleep, and emotional behavior.

Hypothalamic neoplasms can be benign or malignant and can arise from various cell types within the hypothalamus, such as neurons, glial cells, or supportive tissue. These tumors can cause a variety of symptoms depending on their size, location, and rate of growth. Common symptoms include endocrine disorders (such as diabetes insipidus or precocious puberty), visual disturbances, headaches, behavioral changes, and cognitive impairment.

The diagnosis of hypothalamic neoplasms typically involves a combination of clinical evaluation, imaging studies (such as MRI or CT scans), and sometimes biopsy or surgical removal of the tumor. Treatment options depend on the type, size, and location of the tumor but may include surgery, radiation therapy, chemotherapy, or a combination of these approaches. Regular follow-up care is essential to monitor for recurrence or progression of the tumor.

Glioblastoma, also known as Glioblastoma multiforme (GBM), is a highly aggressive and malignant type of brain tumor that arises from the glial cells in the brain. These tumors are characterized by their rapid growth, invasion into surrounding brain tissue, and resistance to treatment.

Glioblastomas are composed of various cell types, including astrocytes and other glial cells, which make them highly heterogeneous and difficult to treat. They typically have a poor prognosis, with a median survival rate of 14-15 months from the time of diagnosis, even with aggressive treatment.

Symptoms of glioblastoma can vary depending on the location and size of the tumor but may include headaches, seizures, nausea, vomiting, memory loss, difficulty speaking or understanding speech, changes in personality or behavior, and weakness or paralysis on one side of the body.

Standard treatment for glioblastoma typically involves surgical resection of the tumor, followed by radiation therapy and chemotherapy with temozolomide. However, despite these treatments, glioblastomas often recur, leading to a poor overall prognosis.

Optic nerve neoplasms refer to abnormal growths or tumors that develop within or near the optic nerve. These tumors can be benign (non-cancerous) or malignant (cancerous).

Benign optic nerve neoplasms include optic nerve meningiomas and schwannomas, which originate from the sheaths surrounding the optic nerve. They usually grow slowly and may not cause significant vision loss, but they can lead to compression of the optic nerve, resulting in visual field defects or optic disc swelling (papilledema).

Malignant optic nerve neoplasms are rare but more aggressive. The most common type is optic nerve glioma, which arises from the glial cells within the optic nerve. These tumors can quickly damage the optic nerve and cause severe vision loss.

It's important to note that any optic nerve neoplasm requires prompt medical evaluation and treatment, as they can potentially lead to significant visual impairment or even blindness if left untreated.

A glioma is a type of tumor that originates from the glial cells in the brain. Glial cells are non-neuronal cells that provide support and protection for nerve cells (neurons) within the central nervous system, including providing nutrients, maintaining homeostasis, and insulating neurons.

Gliomas can be classified into several types based on the specific type of glial cell from which they originate. The most common types include:

1. Astrocytoma: Arises from astrocytes, a type of star-shaped glial cells that provide structural support to neurons.
2. Oligodendroglioma: Develops from oligodendrocytes, which produce the myelin sheath that insulates nerve fibers.
3. Ependymoma: Originate from ependymal cells, which line the ventricles (fluid-filled spaces) in the brain and spinal cord.
4. Glioblastoma multiforme (GBM): A highly aggressive and malignant type of astrocytoma that tends to spread quickly within the brain.

Gliomas can be further classified based on their grade, which indicates how aggressive and fast-growing they are. Lower-grade gliomas tend to grow more slowly and may be less aggressive, while higher-grade gliomas are more likely to be aggressive and rapidly growing.

Symptoms of gliomas depend on the location and size of the tumor but can include headaches, seizures, cognitive changes, and neurological deficits such as weakness or paralysis in certain parts of the body. Treatment options for gliomas may include surgery, radiation therapy, chemotherapy, or a combination of these approaches.

Supratentorial neoplasms refer to tumors that originate in the region of the brain located above the tentorium cerebelli, which is a dual layer of dura mater (the protective outer covering of the brain) that separates the cerebrum from the cerebellum. This area includes the cerebral hemispheres, basal ganglia, thalamus, hypothalamus, and pineal gland. Supratentorial neoplasms can be benign or malignant and may arise from various cell types such as neurons, glial cells, meninges, or blood vessels. They can cause a variety of neurological symptoms depending on their size, location, and rate of growth.

Oligodendroglioma is a type of brain tumor that originates from the glial cells, specifically the oligodendrocytes, which normally provide support and protection for the nerve cells (neurons) within the brain. This type of tumor is typically slow-growing and located in the cerebrum, particularly in the frontal or temporal lobes.

Oligodendrogliomas are characterized by their distinct appearance under a microscope, where the tumor cells have a round nucleus with a clear halo around it, resembling a "fried egg." They often contain calcifications and have a tendency to infiltrate the brain tissue, making them difficult to completely remove through surgery.

Oligodendrogliomas are classified based on their genetic profile, which includes the presence or absence of certain chromosomal abnormalities like 1p/19q co-deletion. This genetic information can help predict the tumor's behavior and response to specific treatments. Overall, oligodendrogliomas tend to have a better prognosis compared to other types of brain tumors, but their treatment and management depend on various factors, including the patient's age, overall health, and the extent of the tumor.

Spinal cord neoplasms refer to abnormal growths or tumors within the spinal cord. These can be benign (non-cancerous) or malignant (cancerous). They originate from the cells within the spinal cord itself (primary tumors), or they may spread to the spinal cord from other parts of the body (metastatic tumors). Spinal cord neoplasms can cause various symptoms depending on their location and size, including back pain, neurological deficits, and even paralysis. Treatment options include surgery, radiation therapy, and chemotherapy.

Astrocytes are a type of star-shaped glial cell found in the central nervous system (CNS), including the brain and spinal cord. They play crucial roles in supporting and maintaining the health and function of neurons, which are the primary cells responsible for transmitting information in the CNS.

Some of the essential functions of astrocytes include:

1. Supporting neuronal structure and function: Astrocytes provide structural support to neurons by ensheathing them and maintaining the integrity of the blood-brain barrier, which helps regulate the entry and exit of substances into the CNS.
2. Regulating neurotransmitter levels: Astrocytes help control the levels of neurotransmitters in the synaptic cleft (the space between two neurons) by taking up excess neurotransmitters and breaking them down, thus preventing excessive or prolonged activation of neuronal receptors.
3. Providing nutrients to neurons: Astrocytes help supply energy metabolites, such as lactate, to neurons, which are essential for their survival and function.
4. Modulating synaptic activity: Through the release of various signaling molecules, astrocytes can modulate synaptic strength and plasticity, contributing to learning and memory processes.
5. Participating in immune responses: Astrocytes can respond to CNS injuries or infections by releasing pro-inflammatory cytokines and chemokines, which help recruit immune cells to the site of injury or infection.
6. Promoting neuronal survival and repair: In response to injury or disease, astrocytes can become reactive and undergo morphological changes that aid in forming a glial scar, which helps contain damage and promote tissue repair. Additionally, they release growth factors and other molecules that support the survival and regeneration of injured neurons.

Dysfunction or damage to astrocytes has been implicated in several neurological disorders, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS).

Anaplasia is a term used in pathology to describe the loss of differentiation and cellular organization in malignant tumors. It is characterized by the presence of large, pleomorphic cells with high mitotic activity, absence of mature tissue architecture, and lack of functional specialization. Anaplastic tumors are often aggressive and have a poor prognosis due to their rapid growth and tendency to metastasize. The term "anaplasia" is derived from the Greek words "ana," meaning "back" or "against," and "plasis," meaning "formation" or "molding."

Cerebellar neoplasms refer to abnormal growths or tumors that develop in the cerebellum, which is the part of the brain responsible for coordinating muscle movements and maintaining balance. These tumors can be benign (non-cancerous) or malignant (cancerous), and they can arise from various types of cells within the cerebellum.

The most common type of cerebellar neoplasm is a medulloblastoma, which arises from primitive nerve cells in the cerebellum. Other types of cerebellar neoplasms include astrocytomas, ependymomas, and brain stem gliomas. Symptoms of cerebellar neoplasms may include headaches, vomiting, unsteady gait, coordination problems, and visual disturbances. Treatment options depend on the type, size, and location of the tumor, as well as the patient's overall health and age. Treatment may involve surgery, radiation therapy, chemotherapy, or a combination of these approaches.

'Tumor cells, cultured' refers to the process of removing cancerous cells from a tumor and growing them in controlled laboratory conditions. This is typically done by isolating the tumor cells from a patient's tissue sample, then placing them in a nutrient-rich environment that promotes their growth and multiplication.

The resulting cultured tumor cells can be used for various research purposes, including the study of cancer biology, drug development, and toxicity testing. They provide a valuable tool for researchers to better understand the behavior and characteristics of cancer cells outside of the human body, which can lead to the development of more effective cancer treatments.

It is important to note that cultured tumor cells may not always behave exactly the same way as they do in the human body, so findings from cell culture studies must be validated through further research, such as animal models or clinical trials.

Ependymoma is a type of brain or spinal cord tumor that develops from the ependymal cells that line the ventricles (fluid-filled spaces) in the brain, or the central canal of the spinal cord. These tumors can be benign or malignant, and they can cause various symptoms depending on their location and size.

Ependymomas are relatively rare, accounting for about 2-3% of all primary brain and central nervous system tumors. They most commonly occur in children and young adults, but they can also affect older individuals. Treatment typically involves surgical removal of the tumor, followed by radiation therapy or chemotherapy, depending on the grade and location of the tumor. The prognosis for ependymomas varies widely, with some patients experiencing long-term survival and others having more aggressive tumors that are difficult to treat.

Central nervous system (CNS) neoplasms refer to a group of abnormal growths or tumors that develop within the brain or spinal cord. These tumors can be benign or malignant, and their growth can compress or disrupt the normal functioning of surrounding brain or spinal cord tissue.

Benign CNS neoplasms are slow-growing and rarely spread to other parts of the body. However, they can still cause significant problems if they grow large enough to put pressure on vital structures within the brain or spinal cord. Malignant CNS neoplasms, on the other hand, are aggressive tumors that can invade and destroy surrounding tissue. They may also spread to other parts of the CNS or, rarely, to other organs in the body.

CNS neoplasms can arise from various types of cells within the brain or spinal cord, including nerve cells, glial cells (which provide support and insulation for nerve cells), and supportive tissues such as blood vessels. The specific type of CNS neoplasm is often used to help guide treatment decisions and determine prognosis.

Symptoms of CNS neoplasms can vary widely depending on the location and size of the tumor, but may include headaches, seizures, weakness or paralysis, vision or hearing changes, balance problems, memory loss, and changes in behavior or personality. Treatment options for CNS neoplasms may include surgery, radiation therapy, chemotherapy, or a combination of these approaches.

Nimustine is a medical term for a specific anti-cancer drug, also known as a cytotoxic chemotherapeutic agent. Its chemical name is nimustine hydrochloride and it belongs to the class of alkylating agents. It works by interfering with the DNA of cancer cells, preventing them from dividing and growing. Nimustine is used in the treatment of various types of cancers, including brain tumors and Hodgkin's lymphoma.

The drug is administered intravenously under the supervision of a healthcare professional, as it can have serious side effects, such as bone marrow suppression, nausea, vomiting, and hair loss. It is important for patients to be closely monitored during treatment with nimustine and to receive appropriate supportive care to manage these side effects.

It's worth noting that the use of nimustine should be based on a thorough evaluation of the patient's medical condition, the type and stage of cancer, and other factors. The decision to use this drug should be made by a qualified healthcare professional in consultation with the patient.

Brain stem neoplasms refer to tumors that originate in the brainstem, which is the lower part of the brain that connects to the spinal cord. These tumors can be benign or malignant and can arise from various types of cells within the brainstem, such as nerve cells, glial cells (which support and protect nerve cells), or cells that make up blood vessels.

Brain stem neoplasms are relatively rare, accounting for about 2% of all primary brain tumors. They can cause a variety of symptoms depending on their size and location, including headache, vomiting, double vision, difficulty swallowing, facial weakness, and problems with balance and coordination. Treatment options may include surgery, radiation therapy, and chemotherapy, depending on the type, location, and extent of the tumor.

Glial Fibrillary Acidic Protein (GFAP) is a type of intermediate filament protein that is primarily found in astrocytes, which are a type of star-shaped glial cells in the central nervous system (CNS). These proteins play an essential role in maintaining the structural integrity and stability of astrocytes. They also participate in various cellular processes such as responding to injury, providing support to neurons, and regulating the extracellular environment.

GFAP is often used as a marker for astrocytic activation or reactivity, which can occur in response to CNS injuries, neuroinflammation, or neurodegenerative diseases. Elevated GFAP levels in cerebrospinal fluid (CSF) or blood can indicate astrocyte damage or dysfunction and are associated with several neurological conditions, including traumatic brain injury, stroke, multiple sclerosis, Alzheimer's disease, and Alexander's disease.

A genetic modifier refers to a gene that influences the expression or penetrance of another gene. In other words, it is a gene that can change the way that a particular genetic trait is expressed. Genetic modifiers do not cause the trait itself, but rather modify its appearance or severity. They can either increase (enhancer) or decrease (suppressor) the effect of the primary gene in question. Modifier genes can help explain why two individuals with the same genetic mutation may have different symptoms or severity of a particular genetic condition.

The optic chiasm is a structure in the brain where the optic nerves from each eye meet and cross. This allows for the integration of visual information from both eyes into the brain's visual cortex, creating a single, combined image of the visual world. The optic chiasm plays an important role in the processing of visual information and helps to facilitate depth perception and other complex visual tasks. Damage to the optic chiasm can result in various visual field deficits, such as bitemporal hemianopsia, where there is a loss of vision in the outer halves (temporal fields) of both eyes' visual fields.

Ganglioglioma is a rare, typically slow-growing tumor that occurs in the brain or spinal cord. It is composed of both neuronal (ganglion cell) and glial elements. These tumors most commonly occur in the temporal lobe of the brain and are usually found in children and young adults.

Gangliogliomas can be benign or malignant, with the majority being low-grade (benign). Symptoms vary depending on the location of the tumor but may include seizures, headaches, changes in behavior or cognition, and motor weakness or paralysis. Treatment typically involves surgical removal of the tumor, and in some cases, radiation therapy or chemotherapy may be recommended.

It's important to note that while I strive to provide accurate information, my responses should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider for any medical concerns.

Dacarbazine is a medical term that refers to a chemotherapeutic agent used in the treatment of various types of cancer. It is an alkylating agent, which means it works by modifying the DNA of cancer cells, preventing them from dividing and growing. Dacarbazine is often used to treat malignant melanoma, Hodgkin's lymphoma, and soft tissue sarcomas.

The drug is typically administered intravenously in a hospital or clinic setting, and the dosage and schedule may vary depending on the type and stage of cancer being treated, as well as the patient's overall health and response to treatment. Common side effects of dacarbazine include nausea, vomiting, loss of appetite, and weakness or fatigue. More serious side effects, such as low white blood cell counts, anemia, and liver damage, may also occur.

It is important for patients receiving dacarbazine to follow their doctor's instructions carefully and report any unusual symptoms or side effects promptly. Regular monitoring of blood counts and other laboratory tests may be necessary to ensure safe and effective treatment.

Medical Definition:

Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic imaging technique that uses a strong magnetic field and radio waves to create detailed cross-sectional or three-dimensional images of the internal structures of the body. The patient lies within a large, cylindrical magnet, and the scanner detects changes in the direction of the magnetic field caused by protons in the body. These changes are then converted into detailed images that help medical professionals to diagnose and monitor various medical conditions, such as tumors, injuries, or diseases affecting the brain, spinal cord, heart, blood vessels, joints, and other internal organs. MRI does not use radiation like computed tomography (CT) scans.

Meningeal neoplasms, also known as malignant meningitis or leptomeningeal carcinomatosis, refer to cancerous tumors that originate in the meninges, which are the membranes covering the brain and spinal cord. These tumors can arise primarily from the meningeal cells themselves, although they more commonly result from the spread (metastasis) of cancer cells from other parts of the body, such as breast, lung, or melanoma.

Meningeal neoplasms can cause a variety of symptoms, including headaches, nausea and vomiting, mental status changes, seizures, and focal neurological deficits. Diagnosis typically involves imaging studies (such as MRI) and analysis of cerebrospinal fluid obtained through a spinal tap. Treatment options may include radiation therapy, chemotherapy, or surgery, depending on the type and extent of the tumor. The prognosis for patients with meningeal neoplasms is generally poor, with a median survival time of several months to a year.

A meningioma is a type of slow-growing tumor that forms on the membranes (meninges) surrounding the brain and spinal cord. It's usually benign, meaning it doesn't spread to other parts of the body, but it can still cause serious problems if it grows and presses on nearby tissues.

Meningiomas most commonly occur in adults, and are more common in women than men. They can cause various symptoms depending on their location and size, including headaches, seizures, vision or hearing problems, memory loss, and changes in personality or behavior. In some cases, they may not cause any symptoms at all and are discovered only during imaging tests for other conditions.

Treatment options for meningiomas include monitoring with regular imaging scans, surgery to remove the tumor, and radiation therapy to shrink or kill the tumor cells. The best treatment approach depends on factors such as the size and location of the tumor, the patient's age and overall health, and their personal preferences.

Nervous system neoplasms are abnormal growths or tumors that occur within the nervous system, which includes the brain, spinal cord, and peripheral nerves. These tumors can be benign (non-cancerous) or malignant (cancerous), and their growth can compress or infiltrate surrounding tissues, leading to various neurological symptoms. The causes of nervous system neoplasms are not fully understood but may involve genetic factors, exposure to certain chemicals or radiation, and certain viral infections. Treatment options depend on the type, location, and size of the tumor and can include surgery, radiation therapy, chemotherapy, or a combination of these approaches.

Thalamic diseases refer to conditions that affect the thalamus, which is a part of the brain that acts as a relay station for sensory and motor signals to the cerebral cortex. The thalamus plays a crucial role in regulating consciousness, sleep, and alertness. Thalamic diseases can cause a variety of symptoms depending on the specific area of the thalamus that is affected. These symptoms may include sensory disturbances, motor impairment, cognitive changes, and altered levels of consciousness. Examples of thalamic diseases include stroke, tumors, multiple sclerosis, infections, and degenerative disorders such as dementia and Parkinson's disease. Treatment for thalamic diseases depends on the underlying cause and may include medications, surgery, or rehabilitation therapy.

The anterior hypothalamus is a region in the brain that has various functions related to endocrine regulation, autonomic function, and behavior. It contains several nuclei, including the paraventricular nucleus and the supraoptic nucleus, which are involved in the release of hormones from the pituitary gland. The anterior hypothalamus helps regulate body temperature, hunger, thirst, fatigue, and sleep-wake cycles. It also plays a role in processing emotions and stress responses. Damage to the anterior hypothampus can result in various endocrine and behavioral disorders.

Human chromosome pair 10 refers to a group of genetic materials that are present in every cell of the human body. Chromosomes are thread-like structures that carry our genes and are located in the nucleus of most cells. They come in pairs, with one set inherited from each parent.

Chromosome pair 10 is one of the 22 autosomal chromosome pairs, meaning they contain genes that are not related to sex determination. Each member of chromosome pair 10 is a single, long DNA molecule that contains thousands of genes and other genetic material.

Chromosome pair 10 is responsible for carrying genetic information that influences various traits and functions in the human body. Some of the genes located on chromosome pair 10 are associated with certain medical conditions, such as hereditary breast and ovarian cancer syndrome, neurofibromatosis type 1, and Waardenburg syndrome type 2A.

It's important to note that while chromosomes carry genetic information, not all variations in the DNA sequence will result in a change in phenotype or function. Some variations may have no effect at all, while others may lead to changes in how proteins are made and function, potentially leading to disease or other health issues.

Neoplasm grading is a system used by pathologists to classify the degree of abnormality in cells that make up a tumor (neoplasm). It provides an assessment of how quickly the tumor is likely to grow and spread. The grade helps doctors predict the prognosis and determine the best treatment options.

Neoplasm grading typically involves evaluating certain cellular features under a microscope, such as:

1. Differentiation or degree of maturity: This refers to how closely the tumor cells resemble their normal counterparts in terms of size, shape, and organization. Well-differentiated tumors have cells that look more like normal cells and are usually slower growing. Poorly differentiated tumors have cells that appear very abnormal and tend to grow and spread more aggressively.

2. Mitotic count: This is the number of times the tumor cells divide (mitosis) within a given area. A higher mitotic count indicates a faster-growing tumor.

3. Necrosis: This refers to areas of dead tissue within the tumor. A significant amount of necrosis may suggest a more aggressive tumor.

Based on these and other factors, pathologists assign a grade to the tumor using a standardized system, such as the Bloom-Richardson or Scarff-Bloom-Richardson grading systems for breast cancer or the Fuhrman grading system for kidney cancer. The grade usually consists of a number or a range (e.g., G1, G2, G3, or G4) or a combination of grades (e.g., low grade, intermediate grade, and high grade).

In general, higher-grade tumors have a worse prognosis than lower-grade tumors because they are more likely to grow quickly, invade surrounding tissues, and metastasize (spread) to other parts of the body. However, neoplasm grading is just one aspect of cancer diagnosis and treatment planning. Other factors, such as the stage of the disease, location of the tumor, patient's overall health, and specific molecular markers, are also considered when making treatment decisions.

Antineoplastic agents, alkylating, are a class of chemotherapeutic drugs that work by alkylating (adding alkyl groups) to DNA, which can lead to the death or dysfunction of cancer cells. These agents can form cross-links between strands of DNA, preventing DNA replication and transcription, ultimately leading to cell cycle arrest and apoptosis (programmed cell death). Examples of alkylating agents include cyclophosphamide, melphalan, and cisplatin. While these drugs are designed to target rapidly dividing cancer cells, they can also affect normal cells that divide quickly, such as those in the bone marrow and digestive tract, leading to side effects like anemia, neutropenia, thrombocytopenia, and nausea/vomiting.

Tuberous Sclerosis Complex (TSC) is a rare genetic disorder that causes non-cancerous (benign) tumors to grow in many parts of the body. These tumors can affect the brain, skin, heart, kidneys, eyes, and lungs. The signs and symptoms of TSC can vary widely, depending on where the tumors develop and how severely a person is affected.

The condition is caused by mutations in either the TSC1 or TSC2 gene, which regulate a protein that helps control cell growth and division. When these genes are mutated, the protein is not produced correctly, leading to excessive cell growth and the development of tumors.

TSC is typically diagnosed based on clinical symptoms, medical imaging, and genetic testing. Treatment for TSC often involves a multidisciplinary approach, with specialists in neurology, dermatology, cardiology, nephrology, pulmonology, and ophthalmology working together to manage the various symptoms of the condition. Medications, surgery, and other therapies may be used to help control seizures, developmental delays, skin abnormalities, and other complications of TSC.

An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.

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