 xenotransplantation (xenos- from the greek meaning "foreign"), is the transplantation of living cells, tissues or organs from one species to another.see also definition of the world health organization such cells, tissues or organs are called xenografts or xenotransplants. in contrast, the term allotransplantation refers to a same-species transplant. human xenotransplantation offers a potential treatment for end-stage organ failure, a significant health problem in parts of the industrialized world. it also raises many novel medical, legal and ethical issues. a continuing concern is that many animals, such as pigs, have a shorter lifespan than humans, meaning that their tissues age at a quicker rate. disease transmission (xenozoonosis) and permanent alteration to the genetic code of animals are also causes for concern. a few successful cases of xenotransplantation are published. it is not uncommon for patients and physicians to use the term "allograft" imprecisely to refer to either allograft (human-to-human) or xenograft (animal-to-human), but it is helpful scientifically (for those searching or reading the scientific literature) to maintain the more precise distinction in usage. ==history==  an american infant girl known as "baby fae" with hypoplastic left heart syndrome was the first infant recipient of a xenotransplantation, when she received a baboon heart in 1984. the procedure was performed by leonard l. bailey at loma linda university medical center in loma linda, california. fae died 21 days later due to a humoral-based graft rejection thought to be caused mainly by an abo blood type mismatch, considered unavoidable due to the rarity of type o baboons. the graft was meant to be temporary, but unfortunately a suitable allograft replacement could not be found in time. xenotransplantation of human tumor cells into immunocompromised mice is a research technique frequently used in oncology research.http://www.ncbi.nlm.nih.gov/pmc/articles/pmc2562196/ it is used to predict the sensitivity of the transplanted tumor to various cancer treatments; several companies offer this service, including the jackson laboratoryhttp://jaxmice.jax.org/jaxnotes
Animal_testing Biology Life_extension Medical_ethics Organ_transplantation