目的 探讨不同水温对大鼠鼻黏膜的损伤及恢复情况。 方法 126只健康成年SD大鼠随机分为A、B、C组，每组42只；A组：常温；B组：50℃；C组：70℃。另设健康成年SD大鼠2只，使用不同温度生理盐水滴入实验组大鼠双鼻中隔黏膜30次，每分钟1次。分别于第30分钟，1、3、7、14、28、42 d各取6只大鼠的刺激区鼻中隔黏膜，对照组取相应区域黏膜制作光、电镜标本观察其病理形态学改变。 结果 A组各时间的光镜下结构正常，在电镜下1、3 d有轻微改变，7 d后基本恢复。B组第30分钟、1 d在镜下有明显损伤，尤其在3 d达严重损伤， 14 d后基本恢复。C组第30分钟，1、3 d在镜下表现出严重损伤，28 d后有少数恢复，42 d后仍未能完全恢复。 结论 常温对大鼠鼻黏膜病理形态学改变较轻，恢复时间短。温度越高、刺激时间越长则病理形态学改变越重，恢复时间越长。
Objective To systematically review the association between periodontal disease during pregnancy and the risk of gestational diabetes mellitus (GDM). Methods PubMed, Web of Science, CBM and CNKI databases were electronically searched to collect studies on periodontal disease and GDM from inception to October 23, 2021. Two researchers independently screened literature, extracted data and assessed the risk of bias of the included studies. Meta-analysis was then performed using RevMan 5.4 software. Results A total of 11 studies were included, involving 2 910 pregnant women. The results of meta-analysis showed that pregnant women with periodontal disease during pregnancy reported more GDM than normal pregnant women (OR=1.81, 95%CI 1.31 to 2.50, P=0.000 3). Conclusion The current evidence suggests that there is a positive association between periodontal disease during pregnancy and the risk of GDM. Due to the limited quantity and quality of the included studies, more high-quality studies are needed to verify the above conclusion.