参莲方对超细颗粒物促发心肌I/R损伤的保护作用研究

目的研究参莲方对超细颗粒物促发大鼠心肌缺血再灌注(ischemia-reperfusion,I/R)损伤的保护作用及机制。方法采用超细颗粒物(DPM 0.1 mg·kg^(-1))染毒基础上结扎冠状动脉左前降支建立超细颗粒物促发I/R大鼠模型,参莲方73、146、292 mg·kg^(-1)灌胃给药,TTC法检测心肌梗死面积,HE染色光镜下观察心肌组织形态学改变,透射电镜观察心肌及微血管超微结构,比色法检测血清中肌酸激酶同工酶(creatine kinase isoenzyme,CK-MB)、穿透素3(pentraxin-3,PTX-3)的含量变化。H9c2细胞经超细颗粒物100μg·mL^(-1)染毒24 h,观察参莲方5、10、20μg·mL^(-1)对其保护作用,比色法检测乳酸脱氢酶(LDH)、CK-MB水平,流式细胞仪检测细胞凋亡率,荧光探针法检测细胞内活性氧(ROS)、细胞线粒体含量、线粒体膜电位,化学发光法检测线粒体Na^(+)-K^(+)-ATP酶活性,Western Blot检测凋亡相关蛋白的表达。结果参莲方可显著减少模型大鼠心肌梗死面积,降低血清中心肌损伤标志物CK-MB和PTX3的含量,减轻心肌组织损伤和炎性细胞浸润,对心肌细胞线粒体结构异常改善明显。体外实验表明,参莲方可降低H9c2细胞LDH、CK-MB、ROS水平,增加线粒体含量,逆转线粒体膜电位丢失,同时显著降低H9c2细胞凋亡率及Caspase-3、Caspase-9蛋白表达,上调Bcl-2蛋白表达。结论参莲方对超细颗粒物促发的心肌I/R损伤保护作用明显,可能与减轻线粒体途径细胞凋亡有关。

Extraction Timing of Heavily Destructed Upper First Permanent Molars

The first permanent molar as the first permanent tooth in the mouth and with a general insufficient oral hygiene of the children, is commonly subject to significant compromise which may arise due to caries or endodontic complication, or from developmental anomalies such as hypoplasia. Compromised teeth with questionable prognosis may result in short- and long-term clinical dilemmas. The aim of this research is to highlight the factors that require careful consideration when a compromised UFPM is detected and the importance of timely UFPM extraction to ensure the mesial drift of the upper second permanent molar (USPM) to fulfill the space of the extracted UFPM without any orthodontic intervention. For this purpose 52 heavily destructed UFPMs were extracted at age of 10.5 years old, 44 (84.6%) USPMs erupted exactly distal to the second premolar while only 7 (13.4%) USPMs erupted 1 mm distal to the second premolar. Clinically it is recommended to extract the heavily destructed upper first molars at age of 10.5 years old to ensure the complete closure of the extraction space by the passive mesial drift of upper second permanent molar.