Xenotransplantation (xeno- from the Greek meaning "foreign") is the transplantation of living cells, tissues or organs from one species to another such as from pigs to humans (see Medical grafting). Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly The cell is the structural and functional unit of all known living Organisms It is the smallest unit of an organism that is classified as living and is often called Tissue is a cellular organizational level intermediate between cells and a complete organism In Biology, an organ ( Latin: organum, "instrument tool" from Greek όργανον - organon "organ instrument In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. In Medicine, grafting is a Surgical procedure to transplant tissue without a blood supply. Such cells, tissues or organs are called xenografts or xenotransplants. The term allotransplantation refers to a same-species transplant. Allotransplantation ( allo- from the Greek meaning "other" is the transplantation of organs between members of the same Species 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 pigs have different lifespans than humans and their tissues age at a different rate. Disease transmission (xenozoonosis) and permanent alteration to the genetic code of animals are also a cause for concern. A zoonosis (ˌzoʊəˈnoʊsɨs or zoonose is any Infectious disease that is able to be transmitted (by a vector) from other Animals both wild and domestic

Because there is a worldwide shortage of organs for clinical implantation, about 60% of patients awaiting replacement organs die on the waiting list. Recent advances in understanding the mechanisms of transplant organ rejection have brought science to a stage where it is reasonable to consider that organs from other species, probably pigs, may soon be engineered to minimize the risk of serious rejection and used as an alternative to human tissues, possibly ending organ shortages.

Other procedures, some of which are being carefully investigated in early clinical trials, aim to use cells or tissues from other species to treat life-threatening and debilitating illnesses such as cancer, diabetes, liver failure and Parkinson's disease. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled Diabetes mellitus (ˌdaɪəˈbiːtiːz or /ˌdaɪəˈbiːtəs/ /məˈlaɪtəs/ or /ˈmɛlətəs/ often referred to simply as diabetes ( Ancient Greek: grc Liver failure is the inability of the Liver to perform its normal synthetic and metabolic function as part of normal physiology Parkinson's disease (also known as Parkinson disease or PD) is a degenerative disorder of the Central nervous system that often impairs the sufferer's If vitrification can be perfected it could allow for long-term storage of xenogenic cells, tissues and organs so they would be more readily available for transplant. Vitrification is a process of converting a material into a Glass -like Amorphous solid that is free from any Crystalline structure either by the quick removal In Biology, an organ ( Latin: organum, "instrument tool" from Greek όργανον - organon "organ instrument

There are only a few published successful xenotransplant procedures. Some patients who were in need of liver transplants were able to use pig livers that were on a trolley by their bedside successfully until a proper donor liver was available^[1].

Problems

Animal testing Main articles Animal testing Alternatives to animal testing Testing on: invertebrates · Frogs · Primates · Rabbits · Rodents Animal testing regulations History of animal testing History of model organisms IACUC Laboratory animal sources Pain and suffering in lab animals Testing cosmetics on animals Toxicology testing Issues Biomedical Research Animal rights/Animal welfare Animals (Scientific Procedures) Act Great ape research ban International trade in primates Controversial experiments Britches · Brown Dog affair Cambridge University primates Pit of despair Silver Spring monkeys Unnecessary Fuss Companies Charles River Laboratories, Inc. Covance · Harlan Huntingdon Life Sciences UK lab animal suppliers Nafovanny · Shamrock Groups/campaigns Americans for Medical Progress AALAS · AAAS Boyd Group · BUAV Dr Hadwen Trust · PETA Foundation For Biomedical Research National Anti-Vivisection Society Physicians Committee for Responsible Medicine Primate Freedom Project Pro-Test · SPEAK Research Defence Society Stop Huntingdon Animal Cruelty Writers/activists Colin Blakemore · Carl Cohen Gill Langley · Ingrid Newkirk Neal Barnard · Jerry Vlasak Simon Festing · Tipu Aziz Categories Animal testing · Animal rights Animal welfare Related templates Template:Animal rights This box: view • talk • edit

Immune rejection remains the biggest challenge for xenotransplantation. Animal testing or animal research is the use of non-human Animals in scientific experimentation. Animal testing or animal research is the use of non-human Animals in scientific experimentation. Most scientists and governments say they agree that Animal testing should cause as little suffering as possible and that alternatives to animal testing' need to be developed See also Animal testing Most animal testing involves Invertebrates, especially Drosophila melanogaster, a fruit Fly, and Frogs have been used in animal tests throughout the history of biomedical science Scientific research involving Non-human primates (NHPs includes Drug pre-clinical Toxicology studies studies of Infectious disease Animal testing on rabbits The Draize Test is an acute toxicity test devised in 1944 by Food and Drug Administration (FDA Toxicologist John H See also Animal testing Rodents are commonly used in animal testing, particularly guinea pigs hamsters gerbils rats and mice Animal testing regulations vary around the world Most governments aim to control the number of times individual animals may be used the overall numbers used and the degree of pain that The history of animal testing goes back to the writings of the Greeks in the third and fourth centuries BCE with Aristotle (384-322 BCE and Erasistratus The history of model organisms began with the idea that certain organisms can be studied and used to gain knowledge of other organisms or as a control (ideal for other organisms of Institutional Animal Care and Use Committees are of central importance to the application of laws to animal research in the United States Animals used by laboratories for testing purposes are largely supplied by dealers who specialize in the trade The extent to which Animal testing causes Pain and Suffering, and the capacity of laboratory animals to experience and comprehend Testing cosmetics on animals is a form of Animal testing, intended to ensure the safety and Hypoallergenic properties of the products for use by humans Toxicology testing, also known as safety testing, is conducted by pharmaceutical companies testing drugs or by contract animal testing facilities Biomedical research (or experimental medicine) in general simply known as medical research, is the Basic research or Applied research conducted "Animal liberation" redirects here for other uses see Animal liberation (disambiguation. Animal welfare refers to the viewpoint that it is morally acceptable for humans to use nonhuman animals for food in animal research, as clothing and in entertainment The Animals (Scientific Procedures Act 1986 (A(SPA 86 is an Act of the Parliament of the United Kingdom (1986 c A great ape research ban, or severe restrictions on the use of non-human Great apes in research is currently in place in the Netherlands, New Zealand, the The international trade in primates sees 32000 wild non-human Primates (NHPs trapped and sold on the international market every year Britches was the name given by researchers to a Stump-tailed macaque monkey born into a breeding colony at the University of California Riverside (UCR in March 1985 The Brown Dog affair was a political controversy about Vivisection that raged in Edwardian England from 1903 until 1910 Cambridge University primate experiments are licensed by the British government for the purpose of research into Brain function The pit of despair, or vertical chamber, was a device used in experiments conducted on Rhesus macaque monkeys during the 1970s by American comparative The Silver Spring monkeys were seventeen Macaque monkeys living inside the Institute of Behavioral Research in Silver Spring Maryland, who became what one writer Unnecessary Fuss is a film produced by Ingrid Newkirk and Alex Pacheco of People for the Ethical Treatment of Animals (PETA showing footage Charles River Laboratories Inc ( is an American Corporation specializing in a broad spectrum of pre-clinical and clinical Laboratory services for the Covance Inc ( formerly Corning Incorporated with headquarters in Princeton New Jersey, is a Contract research organization, (also known as a Clinical research Harlan Sprague Dawley Inc is one of the world's leading suppliers of animals and other services to laboratories for the purpose of Animal testing. Huntingdon Life Sciences (HLS is a contract animal-testing company founded in 1952 in England now with facilities in Huntingdon, Cambridgeshire and Eye Suffolk in the UK Laboratory animal suppliers in the United Kingdom breed animals such as rodents rabbits dogs cats and primates which they sell to licensed establishments for scientific Nafovanny in Vietnam is the largest captive-breeding primate facility in the world supplying long-tailed macaques ( Macaca fascicularis) to animal Shamrock Farm was Britain's only non-human Primate importation and Quarantine centre located in Small Dole, near Brighton in West Sussex Americans for Medical Progress (AMP is a charity that aims to protect and advocate for society's investment in medical research The American Association for Laboratory Animal Science ( AALAS) a 501(c3 nonprofit membership association, was formed in 1950 as a forum for the exchange The American Association for the Advancement of Science (or AAAS) is an organization that promotes cooperation between Scientists defends scientific freedom encourages The Boyd Group is a British based independent Think tank considering issues relating to Animal testing. The British Union for the Abolition of Vivisection ( BUAV) is a British animal protection group based in London UK which campaigns for the complete abolition of all The Dr Hadwen Trust is the UK’s leading medical research charity that funds and promotes exclusively non-animal techniques to replace animal experiments The Foundation for Biomedical Research (FBR is an American lobby group that promotes or defends Animal testing. The National Anti-Vivisection Society is an anti- Vivisection group founded in 1875 and has campaigned for the abolition of experiments on animals for over 100 years The Physicians Committee for Responsible Medicine (PCRM is a Non-profit organization based in Washington D The Primate Freedom Project is a 501(c(3 not-for-profit Grassroots abolitionist Animal rights organization based in Atlanta Georgia Pro-Test is a British group that promotes and supports Animal testing in Medical research. SPEAK the Voice for the Animals is a British Animal rights campaign that aims to end animal experimentation in the UK The Research Defence Society is a British lobby group Its main focus is to disseminate information about and to defend the use of Animal testing in medicine Stop Huntingdon Animal Cruelty (SHAC is an international Animal rights campaign to close down Huntingdon Life Sciences (HLS Colin Blakemore is a British Neurobiologist specializing in vision. Carl Cohen is Professor of Philosophy at the Residential College of the University of Michigan, in Ann Arbor Michigan, USA Dr Gillian Rose Langley (born 1952 is a British scientist and writer who specialises in Alternatives to animal testing, Animal rights and animal protection issues Ingrid Newkirk (born June 11, 1949) is an English-born Animal rights activist author and president and co-founder of People for the Ethical Treatment Neal D Barnard is an American Physician, author clinical researcher and founding president of the Physicians Committee for Responsible Medicine (PCRM Jerry Vlasak (born circa 1958 in Austin Texas) is an American trauma Surgeon and Animal rights activist Simon Festing is the executive director of the Research Defence Society (RDS a British lobby group funded by the pharamaceutical industry and universities Tipu Aziz is a professor of Neurosurgery at the John Radcliffe Hospital in Oxford and a lecturer at Magdalen College Oxford The problem exists even for human to human transplants (known as allotransplantation), but is more serious for transplants between different species. Allotransplantation ( allo- from the Greek meaning "other" is the transplantation of organs between members of the same Species Nearly all mammalian cells have markers which enable the immune system to recognise them as being foreign. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands An immune system is a collection of mechanisms within an Organism that protects against Disease by identifying and killing Pathogens and Tumor The more different the genetic code between the donor organ and recipient, the greater the difference between a "self" marker and a "foreign" marker. Some companies are currently developing transgenic animals such as pigs, that produce human markers to try and lessen the chance of rejection. This article is about organisms which have been genetically modified

Cross-species transplants are more likely to produce host-vs-graft or graft-vs-host reactions than same-species transplants, because of the lack of antigenic similarity. An antigen (from antibody-generating) or immunogen is a substance that prompts the generation of Antibodies and can cause an immune response Organisms which have been genetically engineered to reduce this difference have been produced but are not yet used to any significant degree in medical care. Genetic engineering, Recombinant DNA technology, genetic modification/manipulation (GM and gene splicing are terms that apply to the direct

A worrisome element of xenotransplantation is the potential for infectious disease to spread from the donor animal, which is called xenozoonosis. A zoonosis (ˌzoʊəˈnoʊsɨs or zoonose is any Infectious disease that is able to be transmitted (by a vector) from other Animals both wild and domestic One example is porcine endogenous retroviruses (PERVs) which are viruses within pigs that pigs are immune to, but can infect isolated human cells in cell culture. Endogenous retroviruses are Retroviruses derived from ancient infections of Germ cells in Humans Mammals and other vertebrates as such their Cell culture is the process by which prokaryotic, or eukaryotic cells are grown under controlled conditions ^[2] Some recipients of pig neural cell transplants have had to agree to never donate blood, take frequent blood tests and use safe sex methods for the rest of their lives due to the risk of spreading such viruses. However, the patients who have received these pig cell transplants have yet to show any PERV-type infection. The situation with other animals is currently unknown.

Acceptance

Xenografts have been a controversial procedure since they were first attempted. Many, including animal rights groups, strongly oppose killing animals in order to harvest their organs for human use. Legitimate medical concerns exist about possible disease transfer between animals and humans, such as the porcine endogenous retrovirus found in pig tissues. A disease is an abnormal condition of an organism that impairs bodily functions and can be deadly Endogenous retroviruses are Retroviruses derived from ancient infections of Germ cells in Humans Mammals and other vertebrates as such their Religious beliefs, such as the Jewish and Muslim prohibition against eating pork, may also present concerns for some. PLEASE TAKE NOTE************ A Muslim (مسلم pronounced Muslim, not Muzlim) is an adherent of the Religion

In general, however, the use of pig and cow tissue in humans has been met with little resistance. The tissue is harvested from agricultural animals that were already being butchered, which is less offensive to most people than the idea of raising a primate (which due to its genetic similarity would produce more suitable organs for transplants to humans) solely as an organ donor. A primate is a member of the biological order Primates ( Latin: "prime first rank" the group that contains Lemurs the Aye-aye Similarly, while some individual Jews may not wish to receive a pig valve based on their personal beliefs, the rabbinical view is that the use of pig valves in humans is not a violation of kashruth law. In Anatomy, the heart valves are Valves in the Heart that maintain the unidirectional flow of blood by opening and closing depending on the difference Kashrut (also kashruth or kashrus, he כַּשְׁרוּת refers to Jewish dietary laws. ^[3] In fact, killing a pig in order to save a human life is a requirement in the Jewish faith, under the laws of pikuach nefesh. PLEASE TAKE NOTE************

In 2005, the Australian National Health and Medical Research Council declared a five-year moratorium on all animal-to-human transplantation, concluding that the risks of transmission of animal viruses to patients and the wider community have not yet been resolved ^[4]. For a topic outline on this subject see List of basic Australia topics. The National Health and Medical Research Council (NHMRC is Australia's peak Funding body for Medical research, with a budget of nearly A$1bn a year.

See also

• Medical grafting
• Allograft
• Organ xenotransplantation

References

External links

• PBS Special on Pig to Human Transplants
• Uncaged Campaigns
• Diaries of Despair
• Campaign for Responsible Transplantation
• Xenotransplantation: Risks, Clinical Potential, and Future Prospects Robert E. Michler, 1996
• The Australian National Health and Medical Research Council's 2005 statement on xenotransplantation
• [1] Snapshots of Science and Medicine: Xenotransplantation