My Science School

In 1954, the kidney was the first human organ to be transplanted successfully. Until the early 1980s, the potential of organ rejection limited the number of transplants performed.

 The first ever successful transplant of any organ was done at the Brigham & Women's Hospital in Boston, Ma. The surgery was done by Dr. Joseph Murray, who received the Nobel Prize in Medicine for his work. The reason for his success was due to Richard and Ronald Herrick of Maine. Richard Herrick was a in the Navy and became severely ill with acute renal failure. His brother Ronald donated his kidney to Richard, and Richard lived another 8 years before his death. Before this, transplant recipients didn't survive more than 30 days. The key to the successful transplant was the fact that Richard and Ronald were identical twin brothers and there was no need for anti-rejection medications, which was not known about at this point. This was the most pivotal moment in transplant surgery because now transplant teams knew that it could be successful and the role of rejection/anti-rejection medicine.

Credit : Wikipedia 

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Organ transplantation is a medical procedure in which an organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be transported from a donor site to another location. Organs and/or tissues that are transplanted within the same person's body are called autografts. Transplants that are recently performed between two subjects of the same species are called allografts. Allografts can either be from a living or cadaveric source.

Organs that have been successfully transplanted include the heart, kidneys, liver, lungs, pancreas, intestine, thymus and uterus. Tissues include bones, tendons (both referred to as musculoskeletal grafts), corneae, skin, heart valves, nerves and veins. Worldwide, the kidneys are the most commonly transplanted organs, followed by the liver and then the heart. Corneae and musculoskeletal grafts are the most commonly transplanted tissues; these outnumber organ transplants by more than tenfold.

Organ donors may be living, brain dead, or dead via circulatory death. Tissue may be recovered from donors who die of circulatory death, as well as of brain death – up to 24 hours past the cessation of heartbeat. Unlike organs, most tissues (with the exception of corneas) can be preserved and stored for up to five years, meaning they can be "banked". Transplantation raises a number of bioethical issues, including the definition of death, when and how consent should be given for an organ to be transplanted, and payment for organs for transplantation. Other ethical issues include transplantation tourism (medical tourism) and more broadly the socio-economic context in which organ procurement or transplantation may occur. A particular problem is organ trafficking.[5] There is also the ethical issue of not holding out false hope to patients.

Transplantation medicine is one of the most challenging and complex areas of modern medicine. Some of the key areas for medical management are the problems of transplant rejection, during which the body has an immune response to the transplanted organ, possibly leading to transplant failure and the need to immediately remove the organ from the recipient. When possible, transplant rejection can be reduced through serotyping to determine the most appropriate donor-recipient match and through the use of immunosuppressant drugs.

Credit : Wikipedia 

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Scientists behind the Oxford-AstraZeneca coronavirus shot have produced the vaccine. "This was by far a much more difficult vaccine to make work." Adrian Hill, the Jenner Institute's director, said in northern Tanzania on a visit to field trials of the R21/Matrix-M malaria vaccine.

While the coronavirus responsible for Covid-19 has 12 genes, Plasmodium-the parasite that causes malaria - has more than 5,000 genes. It's an organism that infects the liver and bloodstream, infecting red blood cells.  Hill explains that R21/Matrix-M combines the R21 vaccine with a vaccine booster or adjuvant Matrix-M, which stimulates the human immune system to attack the parasite.  When an infectious mosquito feeds on a human being, it injects parasites in a form called sporozoites into the bloodstream, where they travel directly to the liver. The sporozoites divide rapidly, producing around 20,000 merozoites that rupture the liver cells and invade red blood cells.  R21 targets a circumsporozoite protein (CSP) present on the parasite's surface during the sporozoite stage. CSP rarely mutates among the four strains of malaria parasites that infect humans. The human body does not readily react with a complete immune response to foreign proteins. The R21 focus on CSP boosted by the proprietary Novavax adjuvant- produces a more robust, better-targeted antibody response.  Clinical trials are now moving to the third phase in four countries across Africa - Mali, Tanzania, Kenya, and Burkina Faso.

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