Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «T»:
Transplant, renal: Replacement of a diseased, damaged, or missing kidney with a donor kidney. Also called a kidney transplant.
Patients with end-stage renal failure are candidates for transplantation. A successful transplant frees the patient from dialysis and provides the kidney's other metabolic...
Transplantation genetics: The field of biology and medicine relating to the genes that govern the acceptance or rejection of a transplant.
The most important genes deciding the fate of a transplanted cell, tissue, or organ belong to what is termed the MHC (the major histocompatibility complex). The...
Transplantation, cross-species: See Xenotransplantation....
Transplantation, peripheral blood stem cell
Transplantation, peripheral blood stem cell: A
technique in which stem cells are obtained
from a patient's blood and used in bone marrow transplantation.
Stem cells are small, round cells with a squat nucleus and scant
surrounding cytoplasm. Although unremarkable in appearance, stem
cells can pe...
Transport defect: Within the body, many molecules are able to pass across the membranes that surround cells. These molecules can accomplish this
feat due to specific transport systems. These systems include special receptors on the membrane of the cell and special carrier proteins. The receptor re...
Transport disease, cystine
Transport disease, cystine: Commonly known as cystinuria, this is an inherited (genetic) disorder of the transport of an amino acid (a building block of protein) called cystine. The result is an excess of cystine in the urine (cystinuria) and the formation of cystine stones.
Cystinuria is the most c...
Transporter gene: See: Gene, transporter....
Transposition, genetics: The ability of genes to change position on chromosomes, a process in which a transposable element is removed from one site and inserted into a second site in the DNA. Genetic transposition was the first type of genetic instability to be discovered.
This remarkable phenome...
Transposon: A short mobile DNA
sequence that can replicate and of which copies can be
inserted at random sites within chromosomes. A transposon
has almost identical sequences at each end and inverted
repeat sequences (that run in the opposite direction). It
codes for the enzyme, transposase,...
Transsexual: A person who
desires or has achieved transsexualism. See
Transsexualism: A consistently strong desire to change
one's anatomical gender.
Some transsexuals were misassigned gender at
birth (for example, being anatomically male but raised as female),
either on purpose or due to ambiguous anatomy. Most transsexuals, however, are perfectly normal physical...
Transthyretin: A plasma protein consisting of 127 amino acids that binds retinol and thyroxine. The gene TTR that encodes transthyretin is in chromosome region 18q11.2-q12.1. Many distinct forms of amyloidosis have been related to different point mutations in TTR. Transthyretin is also called prealb...
Transudate: A fluid that passes through a membrane which filters out much of the protein and cellular elements to yield a watery solution. A transudate is due to increased pressure in the veins and capillaries pressure forcing fluid through the vessel walls or low levels of protein the blood serum....
Transurethral resection: Surgery performed with a
special instrument inserted through the urethra. Also called TUR....
Transvaginal ultrasound: A technique in which sound waves are sent out by an ultrasound probe that has been inserted in the vagina. The waves go through the vaginal wall and bounce off the ovaries, and a computer uses the ultrasound echoes to create a picture (a sonogram). Transvaginal ultrasound is...