兔鼻窦炎模型骨质重塑组织学观察及CT评估

Histopathological study and CT evaluation of bone remodeling in rabbit models with rhinosinusitis

目的采用CT扫描并测量兔鼻窦炎模型不同时间及给药后鼻窦骨质CT值,并从组织学水平对标本黏膜及骨质的炎症程度进行评估,探讨不同时间兔鼻窦炎症变化程度、通过CT值评估骨质重塑程度的方法是否可行以及糖皮质激素对于炎症的抑制作用。方法新西兰白兔制成兔鼻窦炎模型。将兔分为A～D共4组:A、B、C组分别为造模后4、8、12周,每组16只;每组再分为给药组和对照组2个亚组,每个亚组8只;D组(造模后饲养12周)8只,不分亚组。造模前所有兔子行鼻窦CT检查作为阴性对照。A、B、C 3个组的对照亚组造模后饲养至预定周数不做处理;给药亚组到周数前2周开始注射地塞米松磷酸钠注射液,2周后行鼻窦CT检查;D组8只在到达实验周数的前4周开始给药,到时行CT扫描。测量兔模型上颌窦骨壁的各幅CT图像中骨质最厚处的CT值。进行CT数据留取后即处死,留取鼻腔鼻窦组织标本,HE染色。每只动物随机选取上颌窦及筛窦切片5张,光镜下观察造模侧的筛窦及上颌窦窦壁的黏膜和骨质,并进行评分。对各组动物CT值、黏膜及骨质评分进行统计学分析,以比较不同时间兔鼻窦炎炎症变化情况、CT值对骨质重塑可否有效评估以及糖皮质激素是否可以抑制黏膜炎症和骨质重塑。结果 A、B、C组造模后CT值均高于正常(t分别为2.747、4.513、7.350,P均<0.05)。各组间黏膜及骨质评分比较显示随造模时间延长均逐渐增加(F分别为3.689、8.493,P均<0.05)。C组给药组与D组间CT值、黏膜评分及骨评分比较均无统计学意义(t分别为1.528、0.000,P均>0.05)。兔鼻窦炎模型黏膜评分与骨评分之间、黏膜评分与CT值之间以及骨质评分与CT值之间具有相关性(相关系数r分别为0.830、0.641、0.586,P均为0.000)。结论通过CT值测量评估兔鼻窦炎骨质重塑程度的方法基本可行,糖皮质激素对于鼻窦炎骨质重塑具有抑制作用。

OBJECTIVE To evaluate the findings of computed tomography（CT）as objective markers of bone remodeling in rabbit models with chronic rhinosinusitis（CRS）.To analyze the inflammation of the mucusa and bone histologically.And to investigate both the feasibility of evaluation of bone remodeling by CT and the inhibitory function of glucocorticoid on the inflammation.METHODS Fifty-six New Zealand albino rabbits were made into rhinosinositis models by vaccination of staphylococcus aureus.The rabbits were divided into 4 groups： group A,B,C and D（4,8,12,12 weeks after vaccination）.There were 16 rabbits in group A,B and C,in each of which the rabbits were medially divided into the medication team and the control team.But there were only 8 rabbits in group D,which was not divided into subgroups.All the rabbits were examined by CT before vaccinated as the negative control.After vaccination of staphylococcus aureus,no interference except CT was done to the control teams of group A,B and C till the scheduled weeks;while Dexamethasone sodium phosphate was administered to the medication teams 2 weeks before their individually scheduled weeks.The rabbits in group D were administered Dexamethasone sodium phosphate 4 weeks before the scheduled weeks.And all the rabbits were examined by CT at the end of scheduled weeks.The Hounsfield unit（HU）of the bone which was the thickest in each image was measured.All the animals were executed after CT exam.We kept the samples of the nasal cavity and paranasal sinuses which were made into slices to be stained by hematoxylin and eosin.Five pieces of slices of maxilary and ethmoid sinus of each animal were randomly selected.The mucous and bone of each slice was respectively scored according to the appearance under light microscope.All the scores and HU data was analysed by statistics to compare the situation of the bone remodeling in different periods and administration in the rabbit models with rhinosinusitis and to prove if the situation of bone remodeling could be evaluated efficiently by measuring the HU,and if the mucous inflammation and bone remodeling could be improved by glucocortitoid.RESULTS Average HU of group A,B and C at the end of the experiments were higher than normal rabbits（t=2.747,4.513,7.350,P 0.05）.The scores of the mucusa and bone were gradually increased as the experiment period lengthened（F=3.689,8.493,P0.05）.There was no statistical difference in the HU and scores of mucous and bone between group C and D（t =1.528,0.000,P 0.05）.There was correlation between the scores of mucous and bone,HU and scores of mucous,Hu and scores of bone in rabbit models with rhinosinusitis（coefficient r =0.830,0.641,0.586,P =0.000）.CONCLUSION It was feasible to evaluate the situation of bone remodeling in rabbit models with rhinosinusitis by measuring the HU.Administration of glucocorticoids could inhibit bone remodeling in rabbit models with rhinosinusitis.