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Background: Autologous vein grafts are widely used for bypass procedures in cardiovascular surgery. However, these grafts are susceptible to failure due to vein graft disease. Our study aimed to evaluate the impact of the latest-generation FRAME external support on vein graft remodeling in a preclinical model. Methods: We performed autologous internal jugular vein interposition grafting in porcine carotid arteries for one month. Four grafts were supported with a FRAME mesh, while seven unsupported grafts served as controls. The conduits were examined through flowmetry, angiography, macroscopy, and microscopy. Results: The one-month patency rate of FRAME-supported grafts was 100% (4/4), whereas that of unsupported controls was 43% (3/7, Log-rank p = 0.071). On explant angiography, FRAME grafts exhibited significantly more areas with no or mild stenosis (9/12) compared to control grafts (3/21, p = 0.0009). Blood flow at explantation was higher in the FRAME grafts (145 ± 51 mL/min) than in the controls (46 ± 85 mL/min, p = 0.066). Area and thickness of neo-intimal hyperplasia (NIH) at proximal anastomoses were similar for the FRAME and the control groups: 5.79 ± 1.38 versus 6.94 ± 1.10 mm2, respectively (p = 0.558) and 480 ± 95 vs. 587 ± 52 μm2/μm, respectively (p = 0.401). However, in the midgraft portions, the NIH area and thickness were significantly lower in the FRAME group than in the control group: 3.73 ± 0.64 vs. 6.27 ± 0.64 mm2, respectively (p = 0.022) and 258 ± 49 vs. 518 ± 36 μm2/μm, respectively (p = 0.0002). Conclusions: In our porcine model, the external mesh FRAME improved the patency of vein-to-carotid artery grafts and protected them from stenosis, particularly in the mid regions. The midgraft neo-intimal hyperplasia was two-fold thinner in the meshed grafts than in the controls. [ABSTRACT FROM AUTHOR]

Aim: Organic anion-transporting polypeptides OATP1B1 and OATP1B3 are sinusoidal membrane transporters mediating liver uptake of a wide range of substrates including conjugated and unconjugated bilirubin, xenobiotics and drugs. Absence of OATP1Bs in the liver causes Rotor syndrome. Our aim was to correlate OATP1B expression with hyperbilirubinemia in common liver diseases., Methods: Immunoreactivity of five antibodies against human OATP1Bs was tested on frozen and formalin-fixed paraffin-embedded liver tissue of mouse strains transgenic for SLCO1B1 or SLCO1B3 and on human specimens. The proportion of hepatocytes expressing OATP1Bs was then assessed immunohistologically in formalin-fixed paraffin-embedded liver samples obtained from patients with hepatocellular and primary biliary liver diseases. UGT1A1 promoter TATA-box and SLCO1B1 rs4149056 genotyping was performed to rule out individuals predisposed to hyperbilirubinemia., Results: The most specific detection of OATP1B3 was achieved with the H-52 (sc-98981) antibody. OATP1B1 was specifically recognized with the ESL (ab15441) anti-OATP1B1 antibody, but only in frozen sections. The MDQ (ab15442) anti-OATP1B1 antibody cross-reacted with both OATP1B proteins in liver tissue of the transgenic mouse strains. Expression of the OATP1B proteins was decreased in advanced liver diseases and inversely correlated with serum bilirubin levels. The reduction was more pronounced in advanced primary biliary diseases (1.9±1.1 vs. 2.7±0.6; P=0.009)., Conclusions: Down-regulation of OATP1B proteins may contribute to pathogenesis of jaundice accompanying advanced cholestatic liver diseases.

Aim: To evaluate the expression of epithelial markers of colorectal carcinogenesis in patients with long-term ulcerative colitis (UC) and primary sclerosing cholangitis (PSC) before and after transplantation., Methods: Eight patients with UC and PSC prior to liver transplantation (PSC-UC), 22 patients with UC after liver transplantation for PSC (OLT), 9 patients with active ulcerative colitis without PSC (UCA), 7 patients with UC in remission (UCR) and 10 controls (N) underwent colonoscopy with multiple biopsies. Specimens were analysed histologically and semi-quantitatively immunohistochemically for p53, Bcl-2 and cyclooxygenase-2 (COX-2) markers. Statistical analysis was performed by Kruskal-Wallis and Fisher's exact tests., Results: PSC-UC had a statistically significantly higher expression of p53 in the nondysplastic mucosa as compared to OLT, UCA, UCR and N (P < 0.05). We also found a statistically significant positive correlation between the incidence of PSC and the expression of p53 (P < 0.001). UCA had a higher p53 expression as compared to UCR. OLT had a significantly lower expression of p53 as compared with PSC-UC (P < 0.001). Bcl-2 had a significant higher bcl-2 expression as compared with controls. No difference in COX-2 expression between PSC-UC, UCR and UCA was found. UCA had higher COX-2 expression as compared to UCR. We also found a statistically significant positive correlation between the expression of COX-2 and p53. Patients after liver transplantation for PSC had a statistically significantly lower expression of the p53 compared with PSC-UC (P < 0.001). PSC-UC had the same inflammatory endoscopic activity as OLT and UCR when evaluated with the Mayo score., Conclusion: Our study shows that the nondysplatic mucosa of UC patients with PSC is characterised by a higher expression of the tumour suppressor gene p53, suggesting a higher susceptibility of cancer. This p53 overexpression correlates with the presence of PSC whilst it is not present in patients with UC after liver transplantation for PSC.

Background: Early postoperative complications after small bowel transplantation (SBT) including endotoxemia, bacterial translocations, and stimulation of the recipient's immune response have been attributed to preservation injury. Small intestine is notoriously sensitive to ischemia and there is still no general agreement as to which segment of the small bowel is preferred (jejunum or ileum) for clinical use., Aim of Study: In our study, using light microscopy and concentrations of tissue serotonin-positive cells we sought to identify the part of the human intestine, which is more resistant to preservation injury sustained by HTK preservation solution with 1-24 hr cold ischemia time., Results: Statistical analysis of both parameters did not reveal any significant differences between the jejunum and ileum., Conclusions: Judging by our data, there is no difference between jejunal and ileal grafts in susceptibility to ischemic injury due to cold ischemia within 24 hours when using HTK preservation solution. Significant difference was observed in histological pictures only after 12-hour of cold ischemia time in both experimental groups (jejunum and ileum).

Interleukin 18 (IL-18) is a potent proinflammatory cytokine involved in the host defence by upregulating both innate and acquired immune responses and may be of particular importance also in mechanisms of kidney allograft rejection. Immunohistochemical staining of protocol biopsies showed constitutive IL-18 expression in the epithelium of distal tubules with the induction of immunoreactivity in acute rejection patients where also proximal tubules, infiltrating leukocytes, and endothelium were strongly positive. Furthermore, serum levels of IL-18 were significantly elevated in patients with acute rejection of kidney allograft (1247+/-389 pg/l) as compared to patients with uncomplicated outcome of kidney transplantation (444+/-164 pg/l) and subjects with acute tubulointerstitial nephropathy (385+/-155 pg/l, p<0.0001 for both comparisons). Tissue culture model of renal epithelial cells expressed IL-18 mRNA constitutively and released mature IL-18 in response to TNF-alpha and IFN-gamma. We assume that upregulation of epithelial IL-18 plays an important role in immune and immunopathological reactions in renal parenchyma and contributes to rejection mechanisms of kidney allograft.