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AIM: To evaluate the efficacy of transplantation of human umbilical cord mesenchymal stem cells(hUCMSCs)in the treatment of corneal alkali burn in rabbits, and study the infiltration of polymorphonuclear neutrophils(PMNs)and the changes of vascular endothelial growth factor(VEGF)expression.METHODS: Corneal alkali burn models were established in right eyes of 75 healthy Japanese white rabbits, which were divided into three groups(group A, B and C), with 25 rabbits in each group. Group A was treated with amniotic membrane combined with hUCMSCs on the day after corneal alkali burn. Group B was treated with amniotic membrane only. Group C did not give any treatment after corneal alkali burn. At 3, 7, 14, 21 and 28d after corneal alkali burn, the corneal recovery was observed by slit lamp and photographed, the growth of corneal neovascularization(CNV)was scored, and corneal tissue was separated to make pathological sections. PMNs infiltration was observed by hematoxylin-eosin(HE)staining, and the expression of VEGF was determined by immunohistochemical staining.RESULTS: The growth of CNV in group A was much slower than that in group B at 14d after alkali burn. The CNV growth score around lesions of group A was significantly lower than that of group B(P<0.05). The quantity of PMNs increased on the 3d with the stromal layer of cornea infiltrated, relatively decreased on the 7d, shown a peak on the 14d, and then decreased gradually. Early infiltration after alkali burn was in the corneal stroma of the lesion area, and the extent of infiltration was equal to the ulcer area at later stage. The cell densities of corneal PMNs in group A and group B were significantly lower than those in group C at all time points after alkali burns(P<0.05), and those in group A were significantly lower than group B at 14 and 21d(P<0.05). The expression levels of corneal VEGF in all groups after alkali burn reached peak at 7～14d and decreased significantly at 28d, and the expression levels of VEGF in group A and group B at all time points after alkali burn were significantly lower than those in group C(P<0.05), and group A was significantly lower than that in group B at 7, 14 and 21d(P<0.05).CONCLUSION: The transplantation of hUCMSCs after alkali burn cornea can reduce the formation of CNV and inhibit corneal revascularization after alkali burn. The corneal pathological lesions and vascularization are closely related to PMNs and VEGF.
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@#AMI: To study the relationship between the infiltration of polymorphonuclear neutrophils(PMNs)and the expression of matrix metalloproteinases 9(MMP-9)in corneal stroma injury after alkali burn.<p>METHODS: Cornea alkali-burned model was made in 25 rabbits, then animals were grouped and sacrificed at 3d, 7d, 14d, 21d and 28d, respectively. The condition developing of alkali-burned cornea was observed by slit lamp biommicroscopy. The corneas were enucleated for histopathological examination. The infiltration of PMNs was identified by hematoxylin eosin(HE)staining and the expression of MMP-9 was identified by immunohistochemisty in different periods.<p>RESULTS: The quantity of PMNs and MMP-9 increased on the 3d, reached the lower level on 7d, shown a peak on the 14d, then decreased gradually. The area and depth of corneal stroma after alkali burn were the most severe on the 14d.<p>CONCLUSION: During the wound healing process, alkali-burned cornea has close relation with the infiltration of PMNs and the expression of MMP-9. The infiltration of PMNs and the expression of MMP-9 is positively correlated in corneal stroma injury after alkali burn.
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AIM: To study the infiltration of polymorphonuclear neutrophils ( PMNs ) after conjunctival flap covering in alkali-burned cornea. ●METHODS: Rabbit cornea alkali-burned model was made, then 50 rabbits were randomly divided into the experimental group ( n=25 ) and the control group ( n=25 ) . At the same time the surgery of conjunctival flap covering was given to rabbits of the experimental group. The condition developing of alkali-burned cornea was observed by slit lamp biomicroscopy, and took photos in two groups. The infiltration of PMNs was identified by hematoxylin eosin ( HE) staining in different periods. ●RESULTS:The quantity of PMNs increased on the 3d, reached the lower level on 7d, shown a peak on the 14d, then decreased gradually. PMNs level of the experimental group was significantly lower than that in the control group, and the difference of 3, 14 and 21d was significant (P ●CONCLUSION: During the wound healing process, alkali - burned cornea has close relation with the infiltration of PMNs. The treatment of conjunctival flap covering for the severe alkali-burned cornea was found to have good effect.