Tissue Allograft

Adhesion molecules also play a crucial role in allograft rejection. The migration of activated T cells from secondary lymphoid organs to the graft site is regulated by adhesion molecules. Furthermore, these molecules are pivotal in the interaction of T cells with the functional components of tissue allografts that are epithelial in origin. 

Lubowitz JH, Schwartzbtag R, Smith P (2015) Cortieal suspensory button versus aperture interference screw fixatiorr for knee anterira cruciate ligamcut soft-tissue allograft a prospective, randomized controlled trial. Arthroscopy 31(9) 1733-1739... 

Lectins may be used as probes for the study of the organization of specific components of chromatin. Three glycoproteins (mol. wt. 6.9 x 10 , 1.25, and 1.35 x 10 ) have been isolated from the non-histone chromosomal proteins from rat liver nuclei. The H-2 major histocompatibility complex is a complex of genes on murine chromosome 17, and is recognised as controlling the rejection of tissue allografts. Of five major peptides isolated from a... 

Soon, M. Y., Hassan, A., Hui, J. H., Goh, J. C., and Lee, E. H. 2007. An analysis of soft tissue allograft anterior cruciate ligament reconstruction in a rabbit model A short-term study of the use of mesenchymal stem cells to enhance tendon osteointegration. Am. J. Sports Med. 35 962-971. 

Skin has also been stored for use as a covering of wounds in bum victims. Preserved skin (allograft) serves as a mechanical and physiological barrier decreases loss of water, protein, and heat and provides strata for the regeneration of viable skin by the victim. The storage medium is usually a tissue culture solution and the skin is wrapped up in gauze that is soaked in this solution and kept for about one week. 

Also known as antibody-mediated rejection, humoral rejection is the process of creating graft-specific antibodies.1,4 This type of rejection occurs less frequently than cell-mediated acute rejection. Humoral rej ection is characterized by deposition of immunoglobulins and complement in allograft tissues. Treatment for this type of rejection is not well defined, yet several reports have shown that treatments such as plasmapheresis, immunoglobulin therapy, rituximab, and/or antithymocyte globulin maybe effective. 

Allograft Tissue or organ transplanted from a donor of the same species but different genetic makeup the recipient s immune system must be suppressed to prevent rejection of the allograft (graft). 

Regele H, Bohmig GA. Tissue injury and repair in allografts novel perspectives. Curr Opin Nephrol Hypertens 2003 12 259-266. 

MacDonald, T.T. and Ferguson, A. (1977) Hypersensitivity reactions in the small intestine. III. The effects of allograft rejection and of graft-versus-host disease on epithelial cell kinetics. Cell and Tissue Kinetics 10, 301-312. 

Bishop, D. K., Jutila, M. A., Sedmak, D. D., Beattie, M. S., and Orosz, C. G. (1989). Lymphocyte entry into inflammatory tissues in vivo. Qualitative differences of high endothelial venule-like vessels in sponge matrix allografts vs. isografts. J. Immunol. 

Azathioprine and mercaptopurine appear to be of definite benefit in maintaining renal allografts and may be of value in transplantation of other tissues. These antimetabolites have been used with some success in the management of acute glomerulonephritis and in the renal component of systemic lupus erythematosus. They have also proved useful in some cases of rheumatoid arthritis, Crohn s disease, and multiple sclerosis. The drugs have been of occasional use in prednisone-resistant antibody-mediated idiopathic thrombocytopenic purpura and autoimmune hemolytic anemias. 

After tissue transplantation, the severity and the period of rejection depend on the tissue type, and this process involves the specificity and memory components of the immune response. Avrion Mitchison in the 1950s observed that allograft immunity could be transferred by the components of the cellular immune response, and antibodies present in the serum that were part of the humoral response were not associated with this process. Future studies delineated the role of T lymphocytes in the allograft rejection process, and the role of both CD4+ and CD8+ cells was established. 

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