Objective To investigate the rat model of cardiac allograft vasculopathy after heart transplantation in rat abdominal cavity. Methods Forty Wistar rats and 40SDrats were divided into control group and experiment group randomly pair-matching. Rat model ofheterotopic heart transplantation was developed. Low doseCyclosporine A were injected into the abdominal cavity in experiment group, while the control group had not received the Cyclosporine A. Transplant hearts were harvested at two weeks and four weeks post-operatively and changes of coronary artery were observed by light microscope. Results There were no alteration of tunica intima of coronary artery in control group at two weeks and four weeks post-transplantation. Tunica intima of coronary artery increased in thickness at two weeks post-transplantation in experiment group and concentric circular change occurred at four weeks post-transplantation. Lumen of coronary artery constricted transparent and cardiac allograft vasculopathy occurred. Conclusion This animal model is reliable of cardiac allograft vasculopathy.
Objective To explore the effect of multimodal interventions in improving the compliance rate of core infection control measures on reducing the incidence rate of vessel catheter associated infection (VCAI). Methods Inpatients with intravascular catheters in 5 departments with high rates of vascular catheterization and infection of Dongguan People’s Hospital between January 2021 and December 2022 were selected. According to the hospital stay, patients were divided into a pre-intervention group (January to December 2021) and a post-intervention group (January to December 2022). The core infection control measures assessment pass rates of medical staff between the two periods and the differences in the incidence rate of VCAI, average catheterization days, and catheterization rate before and after intervention in both groups were compared. Results A total of 8174 patients were included. Among them, there were 3915 patients in the pre-intervention group and 4259 patients in the post-intervention group. In the pre-intervention group, the total length of hospital stay was 122885 days, the total number of catheterization days was 48028 days, and 28 cases of VCAI occurred. In the post-intervention group, the total length of hospital stay was 126966 days, the total number of catheterization days was 51253 days, and 12 cases of VCAI occurred. After intervention, the compliance rate of VCAI core infection control measures was improved [69.21% (2907/4200) vs. 91.24% (3832/4200); χ2=642.090, P＜0.001], the pass rate of medical staff’s core infection control measures assessment was improved [53.33% (128/240) vs. 91.67% (220/240); χ2=88.443, P＜0.001], the catheterization rate was increased [39.08% (48028/122885) vs. 40.37% (51253/126966); χ2=42.979, P<0.001], and the incidence rate of VCAI was reduced [0.58‰ (28/48028) vs. 0.23‰ (12/51253); incidence-rate ratios =0.40, 95% confidence interval (0.20, 0.79), P=0.008]. Conclusions Improving the compliance rate of VCAI core infection control measures through multimodal interventions can significantly improve the passing rates of core infection control measures of medical staffs. This will help to reduce the incidence of VCAI and ensuring patient safety, provide evidence-based support for the prevention and control of VCAI.
ObjectiveTo observe the effect of Delta-like ligand 4 (Dll-4) on the pathological structure of retina in early diabetic rats (DM) and its relationship with vascular endothelial growth receptor-2 (VEGFR-2).MethodsA total of 70 male Sprague-Dawley rats were randomly divided into normal group and DM group, with 10 and 60 rats in each group, respectively. The rats of DM group was induced by intraperitoneal injection of streptozotocin to established DM model. The rats with blood glucose recovery and death were excluded, and the final 60 rats were included in the statistics. Rats in the normal group were injected with an equal volume of citric acid-sodium citrate buffer. Rats in the DM group were divided into DM 1 month (DM 1m) group, DM 2 months (DM 2m) group, DM 3 months (DM 3m) group and DM 3m + Anti group, DM 3m + phosphate buffer solution (PBS) group by random number table method, and 10 rats in each group. In the DM 3m+Anti group, 4 μl of anti-Dll-4 polyclonal antibody was injected into the vitreous cavity, and the antibody concentration was 0.25 mg/ml. The DM 3m+PBS group was intravitreally injected with an equal volume of PBS. Five days after the injection, the rats were sacrificed. Rats in the DM 3m group and the normal group were not treated, and were sacrificed 3 months after the model was established. The structure and microvascular changes of the retina were observed by hematoxylin-eosin staining, and the total thickness of the retina was measured. The expression of Dll-4 and VEGFR-2 in the retina was detected by immunohistochemistry and fluorescence quantitative polymerase chain reaction (PCR). One-way analysis of variance was used to compare the expression of Dll-4 and VEGFR-2 in the retina of each group. The least significant difference t test was used to compare the two groups.ResultsLight microscopy showed that the retinal ganglion cells layer in the DM 3m group were obviously edematous, the inner and outer nuclear layers were thinner, the number of cells was reduced, the arrangement was disordered, the edema of outer plexiform layer was obvious, and the microvessels were abnormally dilated. In the DM 3m+Anti group, the edema of outer plexiform layer was lessened than that of the DM 3m group, and the other layers were not significantly different from the DM 3m group. Compared with the normal group, the total retinal thickness of the DM 3m group, the DM 3m+Anti group and the DM 3m+PBS group increased (t=5.596, 3.290, 4.286; P=0.000, 0.008, 0.002). Immunohistochemical staining showed that a small amount of Dll4 was positively expressed in the retinal ganglion cell layer of the normal group; a small amount of VEGFR-2 was positively expressed in the ganglion cell layer and the inner and outer nuclear layers. The positive expression of Dll-4 and VEGFR-2 in retinal vascular endothelial cells of DM 3m group increased significantly. The expression of Dll-4 was significantly decreased in the retinal layers and vascular endothelial cells of DM 3m+Anti group, while the expression of VEGFR-2 was significantly increased. There was no significant difference between the positive expression of Dll4 and VEGFR-2 in the DM 3m+PBS group and the DM 3m group. The results of real-time PCR showed that the relative expression of Dll-4 and VEGFR-2 mRNA in the DM 3m group was significantly higher than that in the normal group (t=6.705, 20.871; P＜0.05). Compared with DM 3m group, the relative expression of Dll-4 mRNA in DM 3m+Anti group decreased, and the relative expression of VEGFR-2 mRNA increased (t=2.681, 3.639;P＜0.05). The relative expressions of Dll-4 and VEGFR-2 mRNA in the DM 3m+PBS group and DM 3m group were not statistically significant (t=0.513, 0.657; P＜0.05).ConclusionsThe expression of Dll-4 in retinal vascular endothelial cells is gradually increased during the early retinopathy of DM rats. The expression of Dll-4 is inhibited, the expression of VEGFR-2 is up-regulated, and the plexus edema is alleviated.