The Nigerian Mvies

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Thursday 7 August 2014

What You Should Know About Glioblastoma Multiforme

By Annabelle Holman


Primary brain tumors, those that originate in the brain, are more frequent in children and older adults. One feature that sets brain tumors apart from those arising from other tissues in the body is their inability to exit the brain to form secondary, or metastatic, tumors in other organs. They do, however, have a tendency to invade the surrounding brain to establish new tumors within the cranium. The most serious type of intrinsic brain tumor is called glioblastoma multiforme, or GBM.

Intracranial tumors are the most common cause of death by cancer in people under twenty years old. Second only to leukemia, they are the most common cause of cancer death in men aged 20-29. Neural tumors are the 5th leading cause of cancer fatalities in women aged 20-39.

GBM is rare, with only two or three new cases per 100,000 population. They account for one-fifth of all tumors inside the cranium. Because of GBM cells' ability to break away from the main tumor, migrate a few millimeters within the brain and start dividing again to form new tumors, they are impossible to completely eradicate by surgery. It's is like trying to remove all the butter from a slice of toast.

GBM starts in glial cells within the brain, the so-called "helper" cells. While nerve cells stop dividing once they achieve terminal differentiation, glial cells retain the ability to divide throughout the life of the parent organism, i. E., you and me. In vivo studies in the 1960s and in vitro research from the early 2000s seems to indicate that most, if not all, intrinsic brain tumors originate in the developing fetus.

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 are characterized by their starry morphology and the presence of glial fibrillary acidic protein (GFAP). The normal function of astrocytes is to supply nutrients to nerve cells, support the vascular cells that comprise the blood brain barrier and repair damaged cells following trauma. New studies suggest that they communicate with neuronal cells by secreting glutamate, the brain's main 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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