ABSTRACT
Objective:To investigate the effects of early applying of basic fibroblast growth factor (bFGF) on corneal haze formation after surface ablation surgery in rabbits.Methods:The right eyes of 60 healthy New Zealand white rabbits received photorefractive keratectomy (PRK) and were randomized into PRK+ normal saline group, PRK+ bFGF group and simple PRK group, with 20 rabbits in each group.Normal saline solution and bFGF were topically administered according to grouping, respectively, 3 times per day, 1 drop for each time until the sacrifice of the animals, and no drug was used in the PRK group.Another 8 normal rabbits were served as blank control group.The corneal healing response and haze formation were evaluated by anterior segment photography and anterior segment optical coherence tomography (AS-OCT) and graded based on Fantes criteria.Corneal histopathology was examined by hematoxylin-eosin staining.Immunohistochemistry was used to detect the expression of transforming growth factor-β 1(TGF-β 1), α-smooth muscle actin (α-SMA) and matrix metalloproteinase-2 (MMP-2) in cornea.This study protocol was approved by the Experimental Animal Ethic Committee of Affiliated Hospital of Binzhou Medical University (20180209-03). The use and care of the animals complied with the Statement of ARVO. Results:The corneal epithelium was completely healed in 3-4 days following surgery and there was not significantly different in healing time among the three groups.( F=0.57, P=0.57). The haze grading was significantly different among different groups at different time points ( Fgroup=41.736, P<0.01; Ftime=129.445, P<0.01) and showed the highest score in the PRK+ bFGF group on the 28th day after operation.On the 7th day after surgery, AS-OCT image showed that the surface reflection of corneal epithelium was continuous and smooth and corneal epithelium was not tightly attached to the superficial stromal layer; the reflection of the superficial stromal layer was enhanced in all the operation groups.The proliferation of corneal epithelial cells and superficial stromal layer in the operation area were seen under the optical microscope, and the arrangement of collagen fibers in the stromal layer was disordered with the most obvious changes in the PRK+ bFGF group in comparison with the PRK+ normal saline group and the simple PRK group, and these findings became worse on postoperative 28 days.The corneal epithelial surface reflection in the blank control group was continuous and smooth.Immunohistochemistry showed that a few MMP-2 positive cells were seen in the blank control group.TGF-β 1, α-SMA and MMP-2 proteins were positively expressed in the corneas 7 days after surgery in the three groups, and their expressions were the most obvious in the PRK+ bFGF in comparison with the PRK+ normal saline group and the PRK group and were enhanced 28 days after operation, showing statistically differences (all at P<0.05). Conclusions:Early application of bFGF following surface ablation surgery promotes the proliferation of corneal epithelial cells and irregular arrangement of collagen in the superficial stromal layer, which is associated with the expressions of haze-related factors TGF-β 1, α-SMA and MMP-2 in corneas.
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Objective To investigate the effect of conbercept on rabbit's haze after photorefractive keratectomy (PRK).Methods Sixty-four pedigree New Zealand white rabbits were randomly divided into PRK group,normal saline solution group,conbercept 0.5 mg group,conbercept 1.0 mg group,with 16 rabbits in each group.PRK was performed on right eyes,PRK group only received PRK,the other three surgery groups were given postoperative subconjunctival injection of 0.05 ml normal saline solution,0.5 mg (0.0:5 ml) conbercept and 1.0 mg(0.10 ml) conbercept,respectively.In addition,another 8 rabbits were randomly chosen as normal control group.The healing of postoperative corneal epithelial was observed by slit lamp biomicroscope,and the degrees of haze were graded based on Fantes.Eight rabbits in the surgery groups and 4 rabbits in the normal control group were killed in the first week and the fourth week.The corneal tissue was stained by hematoxylin-eosin,and the expressions of transforming growth factor-β1 (TGF-β1),α-smooth muscle actin (α-SMA) and matrix metalloproteinase-2 (MMP-2)were detected by immunochemistry.The use and feeding of experimental animals followed the Relevant Regulations of the Animal Management Committee of Binzhou Medical University.This study protocol was approved by Ethic Committee of the Affiliated Hospital of Binzhou Medical University (No.201701-08).Results Corneal epithelium of all operative rabbits healed completely at 3-5 days and no significant difference in healing time between the groups after operation (F=0.37,P =0.77).The degree of haze in each surgery group reached the highest value at about 4 weeks after operation,and haze in the conbercept 1.0 mg group was the most serious,followed by PRK group and normal saline solution group,haze in conbercept 0.5 mg group was significantly alleviated (Fgroup =20.114,P =0.000;Ftime =8.084,P =0.006).Hematoxylin-eosin staining showed that corneal epithelial cells and fibroblasts in superficial stroma proliferated in one week after PRK,which lead to the disorder of cells and collagen fibers,and the extent of hyperplasia was the same as that of haze.Immunohistochemistry showed that at one week after operation,the expressions of factors in PRK group and normal saline solution group were apparently lower than that of conbercept 1.0 mg group,but were apparently higher than that of conbercept 0.5 mg group,and the expressions of the factors were the weakest in normal control group,with significant differences between them (all at P ＜ 0.05).Conclusions Subconjunctival injection of appropriate conbercept can inhibit the formation of haze and the proliferation of corneal epithelium and superficial stroma,but overdose of conbercept leads to opposite effects.
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Objective To evaluate the effects of high-fidelity simulation training on academic selfefficacy and learning motivation in undergraduate nursing students.Methods 84 undergraduate nursing students were randomized into the control group and the intervention group,nursing students in the control group received traditional health assessment training,while nursing students in the intervention group received health assessment training by high-fidelity simulator.The effects were evaluated by academic self-efficacy,learning motivation and skill performance in undergraduate nursing students.Results There were significant differences on academic self-efficacy,learning motivation and skill performance in undergraduate nursing students between the two groups.Conclusions High-fidelity simulation training can effectively enhance undergraduate nursing students’ academic self-efficacy,learning motivation and skill performance.It is proved to be helpful for competence development in clinical practice.