Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «T»:
Translocation, reciprocal: A type of chromosome rearrangement involving the exchange of
chromosome segments between two chromosomes that do not belong to the same pair of chromosomes.
A specific reciprocal translocation might, for example, involve the swap of material between chromosomes 1 and 19....
Translocation, Robertsonian: A relatively very common and medically significant type of chromosome rearrangement that is formed by fusion of the whole long arms of two acrocentric chromosomes (chromosomes with the centromere near the very end). One in about 900 babies is born with a Robertsonian tra...
Transmissible spongiform encephalopathy
Transmissible spongiform encephalopathy: One of a number of progressive neurodegenerative disorders in animals and humans caused by similar uncharacterized agents that produce spongiform changes in the brain.
Specific examples of transmissible spongiform encephalopathies include:
Transmission distortion: Distortion in the transmission of genes or chromosomes to the offspring, resulting in a significant difference from the Mendelian predictions. As a rule, the chance for a given gene or chromosome to be transmitted to a child is 1:1 or 50%. A number of biologic processes can...
Transmission, perinatal: Transmission of a
disease-causing agent (a
from mother to baby during the perinatal period, the period
and after birth. The perinatal period is defined in diverse
the definition, it starts at the 20th to 28th week of
Transmission, vertical: Transmission of a
disease-causing agent (a
vertically from mother directly to baby during the
perinatal period, the
period immediately before and after birth. The perinatal
period is defined
diverse ways. Depending on the definition, it starts at the
Transmyocardial laser revascularization
Transmyocardial laser revascularization: A procedure by
which a physician uses a laser to make holes in the heart to relieve
the pain of severe angina.
Transmyocardial laser revascularization has been done from both the
outside and inside of the heart. When done from the outside, a laser
Transplant: The grafting of a tissue from one
place to another, just as in botany a bud from one plant might be
grafted onto the stem of another. The transplanting of tissue can be
from one part of the patient to another (autologous transplantation),
as in the case of a skin graft using the p...
Transplant, bone marrow
Transplant, bone marrow: See: Bone marrow transplant....
Transplant, corneal: See: Corneal transplant....
Transplant, hand and forearm
Transplant, hand and forearm: Transplantation of the hand and the forearm from one person (a deceased donor) to another (the recipient).
In the first hand transplant, performed in Ecuador in 1964, the donor hand was rejected after two weeks. The first successful hand and forearm transplant was done ...
Transplant, heart: See: Heart transplant....
Transplant, kidney: See: Kidney transplant....
Transplant, liver: See: Liver transplant....
Transplant, lung: The first
lung transplant was done by the American surgeon James
Hardy (1918-) in 1964. ...