Objective Allograft vasculopathy (AV), feature of chronic rejection, is a major serious long-term post-operation complication in organ transplantation. The accurate mechanisms for AV have not been definitively established, but extensive basic and clinical studies demonstrate AV is triggered by immune reaction and nonimmunologic factors, and also possibly attributed to the metabolism of branched-chain amino acids (BCAA). Methods The transplanted hearts from Lewis to Sprague-Dawely rats served as allografts and those from Lewis to Lewis rats as isografts based on Ono 's model. The differential proteins in transplanted hearts were separated by comparative proteomic technique, and some enzymes which regulated the metabolism of BCAA were identified and validated.Results All transplanted hearts at second week postoperation were characterized by lumen loss (total area-luminal area/total area) in coronary artery, but more predominant at 8th week. All samples from the left ventricles were analyzed by proteomic techniques and the subunits E1 a, E1β and E3 of branched-chain α-ketoacid dehydrogenase (BCKDH) complex were decreased in the heart allografts.Immunohistological detection also showed the expression of BCKDH was reduced not only in the cardiac muscle but also more significantly in blool vessels with cardiac allograft vasculopathy (CAV).BCAA concentrations were increased in the cardiac allografts, but there was no difference in the serum. Conclusion These findings suggest that the catabolic pathways of the BCAA may be inhibited owing to the reduced expression of BCKDH complex, and elevated intracellular concentrations of leucine. The vascular smooth muscle cell and cardiac muscle cell proliferation is stimulated via mTOR-dependent and mTOR-independent pathways, which is associated with the formation of myocardial hypertrophy and AV in the heart allografts.

In this study, using ethylene carbonate and ethanolamine, we synthesized a novel diol chain-extender, bis-hydroxylethyl carbomate (EC-AE), which contains carbomate structure. The polyurethanes, PUA25 and PUB25, with different extenders, EC-AE and BDO, were synthesized by one-step polymerization, respectively. Their structures were characterized by using FT-IR and DSC. The results indicated that the microphase separation degree of PUA25 was less than that of PUB25, in other words, the amount of hydrogen bonding between hard segments and soft segments in PUA25 was superior to that in PUB25. And the formation of physically crosslinked hydrogels prepared by PUA25 and PUB25 were studied in detail. It was found that only PUA25 can form hydrogel in situ from solution state by cooling. And this kind of hydrogels showed the transition cycle of "gel-sol-gel" under "cooling-heating-cooling" thermal cycles, respectively. The results suggested that the physically crosslinked polyurethane hydrogels were easily possessed in high degree of phase mixing.
Biocompatible Materials ; Cross-Linking Reagents ; chemistry ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemical synthesis ; chemistry ; Polyurethanes ; chemical synthesis ; chemistry

Objective To evaluate the CT enterography(CTE)of Crohn's disease (CD)in active state and catabatic state by using the Logistic regression analysis.Methods 6 2 patients with CD diagnosed by clinic,imaging,endoscopy,surgery or pathology were analyzed retrospectively.The CTE features of CD in active state and catabatic state were recorded and compared by using single factor and multiple stepwise Logistic regression analysis,and the Logistic regression model was established.Results There were 62 patients with CD, including 40 in active state and 22 in catabatic state.There were significant differences between the bowel wall thickness,the CT value in arterial phase as well as in portal venous phase,the type of enhancement pattern,pseudodiverticulum of free margin,increased mesenteric fat density,comb sign,enlarged abdominal lymph nodes and cellulitis in active state and those in catabatic state of CD by using single factor analysis (P<0.05).The bowel wall thickness (OR=4.589,95%CI:1.689-11.822),bowel wall uniformity enhancement (OR=0.006, 95%CI:0.001-0.067 )and comb sign(OR=23.112,95%CI:1.707-312.997)were significant features by using Logistic regression analysis. Conclusion The bowel wall thickness,bowel wall uniformity enhancement and comb sign are the independent characteristic CTE features to predict the CD in active state or in catabatic state.The Logistic regression model is helpful in demonstrating the state of CD.