Meningioma, also known as meningeal tumor, is typically a slow-growing tumor that forms from the meninges, the membranous layers surrounding the brain and spinal cord. Symptoms depend on the location and occur as a result of the tumor pressing on nearby tissue. Many cases never produce symptoms. Occasionally seizures, dementia, trouble talking, vision problems, one sided weakness, or loss of bladder control may occur.Risk factors include exposure to ionizing radiation such as during radiation therapy, a family history of the condition, and neurofibromatosis type 2. As of 2014 they do not appear to be related to cell phone use. They appear to be able to form from a number of different types of cells including arachnoid cells. Diagnosis is typically by medical imaging.If there are no symptoms, periodic observation may be all that is required. Most cases that result in symptoms can be cured by surgery. Following complete removal fewer than 20% recur. If surgery is not possible or all the tumor cannot be removed radiosurgery may be helpful. Chemotherapy has not been found to be useful. A small percentage grow rapidly and are associated with worse outcomes.About one per thousand people in the United States are currently affected. Onset is usually in adults. In this group they represent about 30% of brain tumors. Women are affected about twice as often as men. Meningiomata were reported as early as 1614 by Felix Plater. Signs and symptoms
Small tumors (e.g., < 2.0 cm) usually are incidental findings at autopsy without having caused symptoms.
The racemization process can occur in vivo. The process of conversion of one enantiomer to its mirror-image version with no other change in the molecule is called chiral inversion.Celgene Corporation originally synthesized thalidomide using a three-step sequence starting with L-glutamic acid treatment, but this has since been reformed by the use of L-glutamine. As shown in the image below, N-carbethoxyphthalimide (1) can react with L-glutamine to yield N-phthaloyl-L-glutamine (2). Cyclization of N-phthaloyl-L-glutamine occurs using carbonyldiimidazole, which then yields thalidomide (3). Celgene Corporations original method resulted in a 31% yield of S-thalidomide, whereas the two-step synthesis yields 85–93% product that is 99% pure. History
In 1952, thalidomide was synthesised by Chemical Industry Basel (CIBA), but was found "to have no effect on animals and was discarded" on that basis. In 1957, it was acquired by Chemie Grünenthal in Germany. The German company had been established as a soap maker after World War II ended, to address the urgent market need for antibiotics. Heinrich Mückter was appointed to head the discovery program based on his experience working with the German armys antiviral research. While preparing reagents for the work, Mueckters assistant Wilhelm Kunz isolated a by-product that was recognized by pharmacologist Herbert Keller as an analog of glutethimide, a sedative. The medicinal chemistry work turned to improving the lead compound into a suitable drug: the result was thalidomide.