Tryptophan hydroxylase 2, also known as neuronal tryptophan hydroxylase (NTPH), the key rate-limiting enzyme in the synthesis of serotonin (5-hydroxytryptamine, or 5HT). 5HT is causally involved in numerous activities in the central nervous system, and it also has other functions including the maintenance of vascular tone and gut motility. The TPH2 gene is on chromosome 12.
A functional genetic polymorphism (variation) in the TPH2 gene results in the substitution of a single amino acid in the TPH2 protein. This minute change in TPH2 leads to decreased brain serotonin levels and provides direct evidence for a fundamental role of TPH2 in the production of serotonin in the brain. Dysregulation of brain serotonin contributes to some psychiatric disorders.
Total parenteral nutrition.
A partition which divides or partly divides a cavity. One of the strands of connective tissue projecting into an organ that constitutes part of the framework of the organ as, for example, the trabeculae of the spleen. One of a number of small interconnecting rods of bone making up a mass of spongy bone as, […]
A tube-like portion of the respiratory tract that connects the larynx with the bronchial parts of the lungs. Also known as windpipe.
Surgical removal of the cervix, the lower portion of the uterus that protrudes into the vagina. Trachelectomy is done in younger women with early cancer of the cervix (with a tumor no larger than 2-3 centimeters). In this surgery, the cervix and the upper part of the vagina are removed but the rest of the […]
- Tracheoesophageal puncture
A small opening that is made by a surgeon between the esophagus and the trachea. A valve is inserted to keep food out of the trachea but allow air into the esophagus to permit tracheoesophageal speech.