Objective To investigate the usefulness of acoustic radiation force impulse (ARFI) elastography for noninvasive evaluation of liver fibrosis in rats.Methods A total of 70 male Wistar rats were included in the group for dimethylnitrosamine (DMN)-induced liver injury,and 10 saline-injected rats were used as normal control.Hepatic injury was induced by a single intraperitoneal injection of DMN at a dose of 50 mg/kg of body weight.Several rats in the group with DNM injected and the normal control group were randomly selected and sacrificed at each of the following post-injection time:day 5,7,10,14,21,24,and 28.And their livers were taken for pathology analysis.All the rats underwent ARFI elastography before sacrificed in order to acquire a shear wave velocity (Vs) to represent liver stiffness.Correlation between Vs and the histological finding was analysed.ResultsAmong 58 successfully modeled rats,9,13,14 and 12 rats were found to be with S1,S2,S3 and S4 of liver fibrosis pathologically,respectively.And 10 rats were found to be with severe inflammatory activity without any fibrosis.Values of Vs increased with the stage of liver fibrosis ( P ＜0.05).There was a significant correlation between Vs and stage of liver fibrosis ( r =0.947,P =0.000).The areas under ROC curve for the diagnosis of fibrosis S≥S1,S≥S2,S≥S3 and S=S4 were 0.983,0.995,0.999 and 0.964,respectively;for the cutoff values of Vs were 1.59 m/s,2.13 m/s,2.33 m/s and 2.51 m/s,respectively,the sensitivity was 95.8％,92.3％,100％ and 84.6％,and specificity was 100％,100％,96.9％ and 95.6％,respectively.The values of Vs in the group with severe inflammatory activity were significantly higher than those in the control group ( P =0.000).ConclusionsARFI has a relatively high value in the evaluation of liver fibrfosis in rats,while severe inflammatory activity may affect its accuracy.

Introduced in the paper is a success story of the Singapore National Eye Center (SNEC) and Singapore Eye Research Institute (SERI) in medical care,research and education.Especially noteworthy are their initiatives in talent development,research and international cooperation,which are expected to be learnt by large eye care and research institutions in China in their discipline development,translational research and interdisciplinary talents development.

Objective To investigate the role and mechanism of SDF-1/CXCR4 in the development of chronic rejection (CR) in rat models.Methods CR rat models were established using Fisher 344 to Lewis rats.In the blank control group (n=10),Lewis rats getting isotransplantation were treated with Cyclosporine A.CR rat models were established in positive group (n=10) and the rats were treated with Cyclosporine A.CR rat models were also established in CXCR4 antagonism group (n=10) and the rats were treated with both Cyclosporine A and AMD3100 (1 mg/kg).The serum creatinine levels were monitored every week.Kidney grafts were harvested 12 weeks after transplantation for histological analysis.We evaluated graft injuries using chronic allograft damage index (CADI) scores.Q-PCR and Western blotting were used to measure CXCR4,TGF-β1/Smad3 signaling pathway and α-smooth muscle actin (α-SMA) expression in renal allograft tissues.Results The serum creatinine levels in blank control group and CXCR4 antagonism group were significantly lower than those in positive control group (P<0.05).The blank control group and CXCR4 antagonism group presented milder pathological manifestations of CR.The CADI score in CXCR4 antagonism group was 3.54,which was lower than that of positive control group (P<0.05).The expression of biological markers in TGF-β1/Smad3 signaling pathway and SDF-1/CXCR4 signaling pathway was significantly lower in blank control group and CXCR4 antagonism group than in positive control group (P<0.05).Conclusion SDF-1/CXCR4 signaling pathway may play a crucial role in the development of CR.The usage of SDF-1/CXCR4 antagonist can protect renal allograft by inhibiting the TGF-β1/Smad3 pathway.Therefore,antagonism of CXCR4 may provide a novel way to prevent the development of CR.