Intrinsic brain tumors have two features that make them different from other types of cancer. One, is they rarely, if ever, metastasize to other organs in the body. Two, cells often break away from the main mass to invade the surrounding brain and form new growths a few millimeters or more away. These tumors are more common in children and the elderly than in the general population. The most malignant of these is called glioblastoma multiforme (GBM).
Brain tumors are the second most common cause of cancer deaths in males and females under the age of 20. After leukemia, intrinsic brain tumors are the second leading cause of cancer deaths in men between the ages of 20 and 29. They are the fifth most frequent cause of cancer deaths among females between the ages of 20 and 39.
Luckily, GBM is infrequent; there are no more than two or three new cases per 100,000 individuals and account for only 20% of all intracranial neoplasms. Their propensity to invade the surrounding brain tissue means that it is not possible for them to be completely eradicated by surgical means. Try scraping off every bit of butter from a slice of toast.
GBM arises from cells in the brain called glial cells. Neurons, which are generally post-mitotic, meaning they lose the ability to divide once they have achieved terminal differentiation. Glial cells, on the other hand, may continue to divide and replicate throughout life. There is evidence from in vivo and in vitro studies to suggest that some, if not all, astrocytomas arise in utero.
Glial cells come in three different forms: microglia, astrocytes and oligodendrocytes. Of these, astrocytes and astrocytic tumors, are the most common. The nastiest, most malignant and most deadly variant of astrocytoma is the GBM, which has a median time of survival without treatment of less than five months.
Astrocytes, situated in the brain and spinal cord, have several important functions. Among these is providing support to the vascular cells that make up the blood brain barrier, providing nutrients to neuronal tissue and repairing damage caused by CNS trauma. Recent experiments indicate that one way that astrocytes communicate with nerve cells is by releasing glutamate, an excitatory neurotransmitter.
Oligodendrocytes are less spiny than their astrocytic cousins. Their main role in the nervous system is to provide a fatty sheath of insulation that makes more rapid nerve transmission possible. One oligodendrocyte can ensheath up to 50 neurons. The fatty sheath, called myelin, comes under attack from immune system cells in the debilitating condition known as multiple sclerosis (MS).
Microglia are the macrophages of the central nervous system. These cells act quickly recognize and destroy foreign bodies, engulf them and present them to other cells of the immune system, called T-cells, before they get the chance to interfere with healthy brain tissue. Microglia exist in two different forms. Resting cells, which resemble tiny astrocytes, and activated microglia, which are more bloated in appearance.
Brain tumors are the second most common cause of cancer deaths in males and females under the age of 20. After leukemia, intrinsic brain tumors are the second leading cause of cancer deaths in men between the ages of 20 and 29. They are the fifth most frequent cause of cancer deaths among females between the ages of 20 and 39.
Luckily, GBM is infrequent; there are no more than two or three new cases per 100,000 individuals and account for only 20% of all intracranial neoplasms. Their propensity to invade the surrounding brain tissue means that it is not possible for them to be completely eradicated by surgical means. Try scraping off every bit of butter from a slice of toast.
GBM arises from cells in the brain called glial cells. Neurons, which are generally post-mitotic, meaning they lose the ability to divide once they have achieved terminal differentiation. Glial cells, on the other hand, may continue to divide and replicate throughout life. There is evidence from in vivo and in vitro studies to suggest that some, if not all, astrocytomas arise in utero.
Glial cells come in three different forms: microglia, astrocytes and oligodendrocytes. Of these, astrocytes and astrocytic tumors, are the most common. The nastiest, most malignant and most deadly variant of astrocytoma is the GBM, which has a median time of survival without treatment of less than five months.
Astrocytes, situated in the brain and spinal cord, have several important functions. Among these is providing support to the vascular cells that make up the blood brain barrier, providing nutrients to neuronal tissue and repairing damage caused by CNS trauma. Recent experiments indicate that one way that astrocytes communicate with nerve cells is by releasing glutamate, an excitatory neurotransmitter.
Oligodendrocytes are less spiny than their astrocytic cousins. Their main role in the nervous system is to provide a fatty sheath of insulation that makes more rapid nerve transmission possible. One oligodendrocyte can ensheath up to 50 neurons. The fatty sheath, called myelin, comes under attack from immune system cells in the debilitating condition known as multiple sclerosis (MS).
Microglia are the macrophages of the central nervous system. These cells act quickly recognize and destroy foreign bodies, engulf them and present them to other cells of the immune system, called T-cells, before they get the chance to interfere with healthy brain tissue. Microglia exist in two different forms. Resting cells, which resemble tiny astrocytes, and activated microglia, which are more bloated in appearance.
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