Ketamine is a dissociative anesthetic used medically for induction and maintenance of anesthesia. It is also used as a recreational drug. It is one of the safest anesthetics, as, in contrast with opiates, ether, and propofol, it suppresses neither respiration nor heart rate. Ketamine is also simple to administer and highly tolerable compared to drugs with similar effects which are flammable, irritating, or even explosive. Ketamine is a novel compound, derived from PCP, created in pursuit of a safer anesthetic with similar characteristics. Ketamine is also used for acute pain management.At anesthetic doses, ketamine induces a state of "dissociative anesthesia", a trance-like state providing pain relief, sedation, and amnesia. The distinguishing features of ketamine anesthesia are preserved breathing and airway reflexes, stimulated heart function with increased blood pressure, and moderate bronchodilation. At lower, sub-anesthetic doses, ketamine is a promising agent for pain and treatment-resistant depression. However, the antidepressant action of a single administration of ketamine wanes with time. The long-term effects of repeated use are largely unknown, and are an area of active investigation.Liver and urinary toxicity have been reported among regular users of high doses of ketamine for recreational purposes. Ketamine is an NMDA receptor antagonist and that accounts for most of its actions except the antidepressive effect, the mechanism of which is a matter of much research and debate. Ketamine was first synthesized in 1962 and approved for use in the United States in 1970.
Causes
Chromosomal analysis of ASPS shows the breaking and joining of two chromosomes in the tumor cells. A piece of chromosome X breaks and is joined to chromosome 17. This translocation creates a fusion between two genes named ASPL and TFE3, which results in the formation of an aberrant protein (termed fusion protein) that is not found in normal cells. Two sorts of fusions between chromosome X and chromosome 17 are found in different ASPS tumors: type one and type two. Dr. Marc Ladanyi at Memorial Sloan-Kettering Cancer Center, in New York City, has pioneered this work. The resultant fusion protein ASPL–TFE3 is a rogue transcription factor that is the driver of aberrant cellular behavior including uncontrolled cell division and enhanced angiogenesis. Diagnosis
ASPS may exist in the patient’s body for a long time before being diagnosed. It can grow large and push aside surrounding tissues for a long time before causing any discomfort. Therefore, ASPS symptoms may either be a painless swelling, or a soreness caused by compressed nerves or muscles, affecting the range of motion in the area. Pathology
The definitive diagnosis of ASPS is based on its appearance under the microscope (i.e., its histomorphology), and presence of the characteristic chromosomal translocation (i.e., cytogenetics). ASPS histomorphologic features include an alveolar-like pattern at low magnification and the presence of large cells with abundant eosinophilic cytoplasm and eccentric nuclei. Calcifications are commonly present, as may be seen with slow-growing neoplasms. Prognosis
Although ASPS displays a relatively indolent course, the ultimate prognosis is poor and is often characterized by late metastases.