Search This Blog

Tuesday, March 30, 2010

Organ transplantation

TRANSPLANTATION TRANSPLANTATION 
The replacement of tissue or organ either in same or in different organism is called transplantation. This process is used to replace damaged or diseased tissue or organ of the body. 

TYPES OF TRANSPLANTATION: 
On the basis of the relationship of donor and recipient, transplantation is classified into the following type: a)AUTOGRAFT: 
The transplantation in which an isolated portion of living tissue is taken from one part of body and transferred to another part of same individual is called Autograft. Eg: skin graft used for severe burnt skin 

b)ISOGRAFT: 
The transplantation between genetically identical individual is called isograft. Eg the grafting between twins. This type of transplantation is the most successful as donor and recipient are genetically identical. 

c)ALLOGRAFT: 
The transplantation between two individual of same species but with different genetic background. Eg:a heart or kidney transplantation 

d)XENOGRAFT: 
The transplantation between individual of different species. Eg: monkey to man 

ORGAN TRANSPLANTION: 
The replacement of complete organ like kidney, heart ,lung etc. between two individual is called organ transplantation. It is a decisive procedure used in those cases where survival of the animal is in danger. For success donor and recipient must be genetically identical. Organ transplantation is great achievement in medical science. Kidneys have been transplanted for several years with varying degree of success. The first heart transplantation was done in 1967 by Christian Barnard in the USA and since then attempts have been made to graft lungs and liver. The main problem in organ transplantation is that the recipient body recognizes transplanted organ as foreign body or antigen. Therefore, the recipient body produces antibodies against grafted organ. Thus, a foreign organ graft will be rejected by the recipients immune system. This is called rejection. The best known example of organ transplantation is the transport of cornea because cornea does not link with the immune system of the body as well as with the blood supply. Its transplantation is also relatively simple. However, transplantation of other organs like kidney, liver, heart etc. is very complicated as it is not accepted by the human immune system. 

WAY TO PREVENT REJECTION:
1)By using immuno suppressive drugs. These drugs are immuno suppressants. These drugs are very expensive and make the body highly susceptible to infection.
2)Transplantation should be between genetically identical individual like twins. 
3)Immune system can be suppressed by radiation. 
4)Research is still on to develop immuno suppressive drugs which only stop rejection response while the rest of the immune system may remain active to fight other invaders. 
5)Now a days, research is going on for the development of artificial organ as liver and heart. Transplantation of artificial organ is most encouraging. 

ADVANTAGES OF ORGAN TRANSPLANTATION: 
1)Organ transplantation helps in the replacement of damaged or diseased tissue or organ from the body. 2)Organ transplantation is decisive procedure used in those cases where survival of animal is in danger. 3)Organ transplantation is great achievement in medical science. 
4)Organ transplantation is boon to save the life of patients from organ failure. 
5)Organ transplantation is possible to grow sheet of skin from a small piece of skin.This has led to establishment of tissue bank. 
6)Cornea transplantation is are done to restore vision. Bone marrow is transplanted to treat leukemia and disease of blood cells.