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Short answer Yes, brain transplantation is technically possible, but only for short periods of time, and only in experimental settings. Background In terms of a full-brain transplant there has been only one group that have made serious attempts in doing this (according to wikipedia and a literature search on my end). In the 1960's White and colleagues ...


8

This is a very interesting question. One of the most important considerations in patients on long-term immunosuppression is the risk of complications, whether infections or (more dangerously) cancer development; because of this if we can taper the dose then we would like to. This paper specifically discusses a lot of those risks. You mention prednisolone ...


5

DNA will be never replaced (unless you are speaking about something, where DNA might be only trash, like in the case of blood transplantation or in the case when "organ" would be slowly replaced itself by host regenerative power and "organ" transplantation would be only something temporary, but then we are probably speaking about wider definition of organs). ...


5

Short answer Neural xenografts can survive and form functional connections in the host. Background Across-species (xenogeneic grafting) grafting of cerebral cortex from a fetal rat to an adult mouse brain and vice versa, have shown that immunocompetent hosts can reject a graft in less than 30 days. Rejection results in destruction of the graft tissue ...


5

Here is a really interesting article discussing this topic and finding no statistically significant difference in survival rates between donations across race and those within a race.


5

No, race is not a factor taken into account. However, due to higher genetic similarities between people of the same race, it is usually easier to find a match within a race. Source 1 Source 2


4

Capillaries only transport blood for short distances, and within an organ. The blood supply to/from a major organ is generally carried over a few major blood vessels (usually one artery, one vein). Splicing such larger blood vessels are what surgeons earn their pay to do. In terms of nerves, most transplanted organs function fairly well without being ...


4

This is a diagram of a cross-section of the cornea: It is an amazing but relatively simple structure, the shape of which is responsible for about 60% of our focusing power, and the clarity of which allows light to enter. It is avascular (no blood vessels), and the non-mylenated nerve endings are very tiny and present in the epithelium. Transplanting this ...


4

The root of the problem in this case are not the antibodies but the antibody producing cells (APC). They are capable of producing vast amounts of antibody, so I doubt that this approach would be successful. The problem with targeting these APCs is, that you have to know exactly which are the ones which cause the problem, if you want to target them ...


4

Within an organism, antibodies which bind to other antibodies in the body would be eliminated during clonal selection. They are not made by the body after that period, which is in the first few months of life. Such antibodies would have to be introduced from the outside. Many have been designed or engineered for biotech and as therapeutics.


3

The transplantation is an equivalent of a process that naturally occurs in human body, homing of the hematopoietic stem cells. Immature hematopoietic stem cells have the ability to pass the bone marrow barrier, and therefore is able to migrate between bones and other organs within an individual. (e.g. thymus, which is how it can produce T cells.) Williams ...


3

No. MHC works differently from any other antigen. MHC is involved in the maturation of T lymphocytes in the thymus. Forming lymphocytes need to recognise the MHC with a certain affinity (lymphocytes with too much affinity for the MHC are destroyed). In all this process there is no intervention of foreign antigens, so the system you propose won't work because ...


3

As Mowgli pointed out, a bone marrow transplant involves destroying the patient's own immune system with radiation and, essentially, replacing it with a new one from the bone marrow donor. If you did a double kidney/bone marrow transplant from Alice into Bob, then Bob's new immune system (which is the same as Alice's) would recognize the new kidney from ...


2

Bone marrow transplant requires to first destroy the pre-existing immune system with chemotherapy and/or radiations. So essentially you would not have the first immune system and my guess is that yes, in theory, it would work. However, double-grafting an artificially immunocompromised patient (who clearly suffers from another severe pathology, if they need ...


2

Could a viable organ be partially grown in a test tube then be hooked up to the host in some way until it is large enough to swap it with the bad organ? Yes. This conceptual possibility already is a reality for one organ, namely the skin. For an example see the following story in a good scientific journal: https://www.sciencemag.org/news/2017/11/boy-rare-...


2

A cross was done among plant with the desired trait to create the breeding population. The breeding population was usually phenotypically selected for desirable traits. That phrase is confused. To phenotypically select from a breeding population, you first have to generate the breeding population, which requires an initial cross of desired plants. The ...


2

I think that immune rejection is not the only major problem in head transplantation. We are quite skilled at suturing vasculature, but it's not fully solved yet how can you make new and proper connections in the spine? Concerning your questions, if you just took these naive lymphocytes, they would probably get destroyed by the acceptor's immune system ...


2

This was too long for a comment, but I have absolutely no evidence for what I'm about to say :) It looks like that sentence was a little bit of hand-waving, as the author didn't want to categorically state that identical twin tissue would never be rejected. I suspect that in the early days there may have been reports of organ failure (esp. kidneys) in the ...


2

Cornea is considered as an "immune-privileged" site and tissue, neither HLA nor blood grouping is required for allogeneic corneal transplant. In terms of reference: This could be one: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2802514/


1

I have the impression that the MNT article is significantly over-stating the potential of this technique, at least with current technology. The mouse work by Xiaoping Ren (see this 2014 paper) seems to have a very steep death-curve post-surgery: Forty Kunming mice and forty C57 wild type underwent the AHBR procedure. After transplantation, 18 mice ...


1

The situation is just as you'd imagine. In an immunocompetant recipient, a host-versus-graft reaction occurs. This is called transplant rejection. Single episodes (acute rejection) are easy to treat and rarely lead to organ failure. Chronic rejection is the leading cause of organ transplant failure. The organ slowly loses its function and symptoms start to ...


1

MattDMo, I think you're right on. Also remember the thymus is where T-cell recombination and maturation occurs during fetal development, and rates are highest during neonatal period through pre-adolescent childhood - long after sharing a womb. The immune system keeps developing during childhood. It's the immune system that's responsible for tissue ...


1

Antibodies are already widely used in treatment of organ transplant rejection. However their targets are not donor specific antibodies as you proposed. Current anti-rejection antibody based treatment targets T lymphocytes (Basiliximab/Anti-thymocyte globulin/Anti-lymphocyte globulin/Campath etc.), B lymphocytes/plasma cells (Rituximab/bortezomib etc.). Here ...


1

Problems: Where are the anti-antibodies created? In a mouse or in a human? Well, of course, you can't use humans to create antibodies so we are left with mice. So what's wrong with that? Anti-antibodies will be created to the Fc (the constant section of the antibody) region of the antibody because the antibody is foreign and is treated as a foreign antigen....


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