AIM: To investigate the effects of protein C activator (PCA) from Agkistrondon acutus venom ( AAV) on the tension of thoracic aorta rings isolated from the rats with sepsis.METHODS:The model of sepsis was es-tablished by intraperitoneal injection of lipopolysaccharide ( LPS) .SD rats were randomly divided to 6 groups ( n=6 ):sham group, LPS group, PCA intervention group (LPS+PCA, PCA at doses of 0.1 mg/kg, 0.3 mg/kg and 0.6 mg/kg) and LPS+polymyxin B (at dose of 0.2 mg/kg) group.Using perfusion experiment in vitro, the tension of the aortic rings was measured by biological signal analytical system.RESULTS:The values of MABP, HR, LVDP and ±dp/dtmax were significantly lower in LPS group than those in sham group and LPS+PCA groups.Compared with sham group, the relaxa-tion response to acetylcholine ( ACh) and the contractile response of aorta rings induced by phenylephrine ( Phe) were sig-nificantly decreased in LPS group, which were increased significantly in PCA intervention group ( especially at dose of 0.6 mg/kg) compared with LPS group.The dose-response curve of aorta contraction with denuded endothelium induced by Phe shifted down significantly in LPS group compared with sham group, and no significant difference between LPS group and PCA intervention group was observed.Also no statistical difference was found in non-endothelium dependent relaxation of aortic rings induced by sodium nitroprusside among the groups.Pretreatment of N-nitro-L-arginine methl ester and methyl-ene blue increased the contraction amplitude of aortic rings induced by Phe.CONCLUSION:PCA from AAV effectively reverses the hypoergia of the vessels in rats with sepsis through protecting vascular endothelium, the mechanism of which may be mediated by inhibiting NO-GC-cGMP signal transduction pathway.

Objective:To evaluate the reliability of cardiac late iodine enhancement dual-energy CT (LIE-DECT) multiparameter post-processing technique for evaluating the presence, location, and extent of cardiac scars in patients with heart failure (HF), using cardiac MR (CMR) late gadolinium enhancement (LGE) as a reference standard.Methods:Thirty-nine HF patients who underwent cardiac LIE-DECT and LGE-CMR examinations in the Second Affiliated Hospital of Nantong University from November 2019 to November 2021 were prospectively collected, all enrolled HF patients underwent LIE-DECT post-processing to reconstruct monoenergetic plus (Mono+) map (40 keV), iodine map and Rho/Z map, to evaluate the enhancement degree, location and extent of left ventricular myocardial LIE on the left ventricular short-axis map, respectively, and compared with LGE-CMR. Cohen′s Kappa test was used to assess the intra-and inter-observer consistency of LIE by DECT multiparameter technique and the consistency of LIE presence and location by DECT multiparameter technique and by CMR. The diagnostic efficacy of DECT multiparameter technique in diagnosing myocardial scar was calculated.Results:Of the 39 patients included, 32 patients were detected by CMR with LGE in 147 segments, including 37 subendocardial patterns, 19 transmural patterns, 74 mid-wall patterns, and 17 epicardial patterns. The intra-observer consistency Kappa values of 40 keV Mono+map, iodine map and Rho/Z map were 0.878, 0.930 and 0.835 ( P all<0.001), respectively. The inter-observer consistency Kappa values were 0.838, 0.892 and 0.808 ( P all<0.001), respectively. The LIE of 40 keV Mono+map, iodine map and Rho/Z map were in good agreement with CMR, Kappa values were 0.903, 0.883 and 0.810 ( P all<0.001), respectively. For the per-patient analysis, the accuracies of 40 keV Mono+map, iodine map and Rho/Z map were 92.3% (36/39), 92.3% (36/39) and 82.1% (32/39), respectively. For the segment-based analysis, the accuracies of 40 keV Mono+map, iodine map and Rho/Z map accuracy were 96.1% (492/512), 95.3% (488/512) and 92.6% (474/512), respectively. In Bland-Altman analysis, the consistency bias between scar extent measured by 40 keV Mono+map, iodine map, Rho/Z map and that measured by LGE-CMR were -2.03%, -2.21%, -2.65%, and the 95% limit of agreement were -12.20%-8.14%, -12.69%-8.28% and -14.85%-9.58%, respectively. Conclusion:LIE-DECT multiparameter technique can detect myocardial scar in HF patients well, which is consistent with LGE-CMR.