Tissue transplantation fibrosis

Hepatic cirrhosis is typically the end stage of liver disease. Cirrhosis describes an irreversible change (Treinen-Moslen, 2001) characterized by accumulation of excessive collagen deposition in the form of bridging fibrosis which disrupts the hepatic architecture. Cirrhosis may be micronodular or macronodular depending on the amount of fibrosis and tissue regeneration. Liver transplantation is the only solution to restore adequate liver fimction in human medicine. 

Fig 1 41 Section of interventricular septum from a patient who underwent cardiac transplantation 676 days after implantable cardioverter-defibrillator lead implantation and 7 days after last defibrillator shock (a). Right ventricular surface of interventricular septum (R) is at the top and left ventricular surface (L) at bottom. Characteristic fibroelastic tissue encircles the lead curved arrow). Trichrome-stained section of tissue (b) band of fibroelastic tissue curved arrow) encircles lead (L), and beneath, in myocardium, lies fibrous connective tissue F). Area of confluent fibrous connective tissue immediately adjacent to lead also extends into surrounding myocardium, forming radial pattern of interstitial fibrosis arrows), suggesting that shocks have caused lines of electrical injury (courtesy [51])... 

In addition, in vivo C MR spectroscopy has been applied to the study of adipose tissue composition in disease. Children with cystic fibrosis were shown to have lower levels of polyunsaturated adipose tissue fatty acids than healthy children, possibly owing to a disorder in essential fatty acid metabolism that may be partly responsible for the development of the disease. Further studies with in vivo MRS in disease have shown a significant increase in saturated adipose tissue fatty acids following transplantation and subsequent weight gain in malnourished patients with liver cirrhosis. It was suggested that this increase in saturated fatty acids may be secondary to a general repletion of membrane polyunsaturated fatty acids or the use of essential fatty acids for biosynthesis of eicosanoids in the postoperative period. 

Regardless of the cell type used, many barriers must be overcome for the field of CSC transplantation therapy to move forward and become clinically applicable. For example, it is not yet known how to keep a majority of the transplanted cells alive for more than a few days (Zhang et al., 2010), and therefore, for any cell-based therapy to work effectively, a prosurvival strategy should be developed, since in the harsh hypoxic environment of the infarcted heart one expects the level of cell death and fibrosis to be significant. In addition, the impact of parameters such as the optimal number and timing of stem cell transplantation post-MI are currently unknown. The success of cell transplantation for cardiac tissue... 

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