Authors:Balázs Nemes, P. Sótonyi, G. Lotz, A. Heratizadeh, F. Gelley, C. Doege, M. Hubay, Zs. Schaff and B. Nashan
In chronic liver rejection lymphocyte mediated processes lead to chronic inflammation, necrosis and repair mechanisms. The aim of the present study was to investigate the expression of apoptosis related proteins (FAS/APO-1, FAS-L, Bcl-2, Bax, TNF-α, and INF-γ). ApopTag reaction and immunohistochemistry were performed on liver samples of chronically rejected allografts and compared with normal donor livers. In chronic rejection, apoptosis was detected in pericentral hepatocytes and in the biliary epithelium. Bcl-2 was strongly expressed on lymphocytes around the bile ducts, but not on the biliary epithelium itself. Bax, FAS, TNF-α and INF-γ were present in pericentral areas. T-cells showed up around bile ducts, whereas macrophages around pericentral areas. In pericentral areas apoptosis seems to be fostered through TNF-α and INF-γ and by the lack of Bcl-2. Based on these results both downregulation and upregulation of apoptotic proteins can be observed in chronic liver allograft rejection: FAS is upregulated in biliary epithelium and zone 2, protein levels of FASL remain unchanged, BAX is upregulated in zone 3, BCL2 is downregulated in both biliary epithelium and zone 1 and both TNFa and IFN are upregulated in zone 3. Our results suggest that the balance between pro- and antiapoptotic patterns was shifted to the proapoptotic side, mainly in the centrilobular area of the hepatic lobule, and in the bile ducts. According to these findings in chronic rejection the predictive sites of apoptosis are the biliary epithelium and the pericentral areas.
Authors:E. Gyurkovics, P. Arányi, Zs. Turóczi, D. Garbaisz, M. Varga, V. Hegedüs, G. Lotz, P. Kupcsulik and A. Szijártó
External aortic compression due to acute gastric dilation is a rare etiology of the lower limb ischemia. This phenomenon leads the author to design experimental study for reperfusion syndrome. The lower limb ischemia-reperfusion (IR) injury consists of local and systemic components called the reperfusion syndrome. It can progrediate into a multi-organ failure which defines postoperative survival. A postconditioning is a surgical technique, which has a potential to reduce IR injury, therefore to prohibit the development of reperfusion syndrome.
XXXto examine on an experimental model, whether postonditioning is a practicable technique in infarenal aortic surgeries.
Materials and Methods
Male Wistar rats underwent 180 minutes of infrarenal aortic occlusion with 4, 24 and 72 hours of reperfusion. Postconditioning (10 sec. reocclusion / 10 sec. perfusion in 6 cycles) was applied in one group of each reperfusion time. Blood, urine, and histological (muscle, lung, kidney and liver) samples were collected at the postischemic 4th, 24th, and 72th hour.
The early inflammatory response (TNFa, free radicals) and late local inflammation were reduced by posctonditioning significantly. Postconditioning was able to reduce the remote organ injury of lungs and kidneys, the morphological and laboratorial results showed significant difference between the postconditioning and the control group in these two organs. The method's positive effect on remote organ injury remained long-term.
Postconditioning seems to be an applicable process to reduce both local inflammatory and systemic complications of IR injury following vascular surgeries.