our p b p n blog.
this is : liveric.blogspot.com
A blog set up for the subject
Principles of Biochemistry & Physiology for Nutrition (PBPN)
by students of A7A1
just for Mdm Kalpana!:D
Our Question:
Our immune system tends to mount an immune response to the entry of an antigen from the same species (e.g. renal transplant).
- Discuss on the factors to be considered to prevent renal transplant rejection.
- Artificial implants (like pace makers, knee/hip joints?) and corneal transplants are not rejected by our immune system? Why?
Topic of Discussion:
* What is Immune System and How Does It Work?
* Renal Transplant Rejection
* Artificial implants and Corneal Transplants
* Q&A Session
* Interesting Facts!!
* Glossary
navigations are on top.=)
Sunday, February 8, 2009
Topic:
Q&A session with Dr. Koji Yo, University of Tokyo
Questions:
1. What are the other causes of renal transplant rejections?
2. What are the most common type of rejections (hyperacute, acute and chronic)?
3. What is immunosuppresin? What are the side effects?
4. Is there any possibility that artificial implants can cause inflammation?
5. How is T-cells responsible for rejection?
1. Besides the rejection by MHC, the antibody in the recipient’s serum can cause hyperacute rejection. Those antibodies are not induced after transplantation, but they are those that the recipient has in his/her body. This rejection is untreatable. In order to prevent this reaction, the existence of the antibodies responsible for the donor’s antigen should be confirmed before transplantion by crossmatch test.
2. Generally, hyperacute rejection is rare, while acute one is quite common. However, because of the progress of drug therapy, acute rejection doesn’t always present the characteristic symptoms, and now it is often difficult to diagnose it precisely.
3. Major immunosuppresins:
Cyclosporine (suppress T cell function)
Side effects: renal toxicity, hypertension, finger tremor etc.
Predonisolone (steroid)
Side effects: diabetes mellitus, gastrointestinal ulcer, cataract etc.
Azathioprine (block DNA synthesis and T cell proliferation)
Side effects: loss of leukocytes, hepatotoxicity etc.
All of them may cause severe infection.
4. Taking pacemaker as an example, there are two kinds of risks of infection. One is the infection at the skin where the pacemaker is planted, and the other is the lead inserted into the heart. To prevent the infection, antibiotics are used after the operation for a few days.
5. Helper T cells or Th cells recognize non-self antigen with MHC presented on the cell surface of the recipient’s own antigen presenting cells. Th cells are activated and produce proteins called cytokine that mediate the inflammation process. Differentiation of T cell into cytotoxic T cell (CTL) occurs. CTL attacks the cells from the donor by penetrating the cell membrane and destroying the DNA of the target cells or by inducing cell death called apoptosis through the cell membrane protein called Fas.
