丹参酮ⅡA通过PKC/Cx43通路减轻大鼠心肌缺血再灌注致心律失常

目的 探讨丹参酮Ⅱ_A(TA)对再灌注致心律失常的改善作用及机制。方法 取60只SD大鼠随机分为6组：对照组,模型组,TA低、高剂量(10、20 mg·kg^-1)组,蛋白激酶C(PKC)激活剂PMA(5 mg·kg^-1)组,TA(20 mg·kg^-1)联合PKC抑制剂Rottlerin(5 mg·kg^-1)组,每组10只。构建SD大鼠心肌缺血再灌注(I/R)模型,缺血30 min再灌注30 min;再灌注期间记录各组小鼠Ⅱ导联心电图并对再灌注后心律失常严重性进行评分;再灌注结束后,取颈静脉血采用试剂盒检测心肌损伤指标肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)、天冬氨酸转氨酶(AST)和心肌肌钙蛋白(cTnT)水平;取左心室心脏组织,使用试剂盒检测丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性,实时荧光定量PCR(qRT-PCR)法检测PKC、缝隙连接蛋白43(Cx43)mRNA表达,Western blotting法检测PKC、Cx43蛋白表达水平和磷酸化水平。结果 ...     

nNOS抑制剂亚胺基烯丁基-L-鸟氨酸对心肌缺血再灌注损伤的影响及机制

目的 探讨nNOS选择性抑制剂亚胺基烯丁基-L-鸟氨酸(L-VNIO)对心肌缺血再灌注(I/R)损伤的影响及机制。方法 构建SD大鼠离体心脏I/R模型和H9c2细胞缺氧/复氧(H/R)模型;nNOS抑制剂L-VNIO(10μmol·L-1)持续给药整个再灌注或复氧过程。TTC染色测定心肌梗死面积;流式细胞术检测H9c2细胞凋亡率;Fluo-3/AM Ca²⁺荧光探针通过流式细胞仪检测H9c2细胞内Ca²⁺浓度;试剂盒法测定离体心脏灌流液乳酸脱氢酶(LDH)、丙二醛(MDA)水平以及H9c2细胞MDA水平和超氧化物歧化酶(SOD)活性;离体心脏提取肌浆网,试剂盒法检测肌浆网Ca²⁺-ATP酶(SERCA)活性,Western blotting检测肌浆网SERCA蛋白表达;Western blotting检测离体心脏中受磷蛋白(PLB)和兰尼碱受体2(RyR2)蛋白表达水平和磷酸化水平。结果 与I/R或H/R模型组相比,L-VNIO显著降低细胞凋亡率,减少心肌梗死面积,降低LDH、MDA水平,提高SOD活性,差异均有统计学意...     

基于跟骨前部外侧壁和载距突解剖分区的载距突精准置钉技术的应用研究

目的评价基于跟骨前部外侧壁和载距突解剖分区的载距突精准置钉应用于Sanders Ⅱ、Ⅲ型跟骨骨折治疗的效果。方法按"四分法"把跟骨前部外侧壁分为前上区(S1)、前下区(S2)、后上区(S3)和后下区(S4), 用于标定进钉点;"三段法"把载距突分为前段、中段和后段, 用以标定置钉靶点。标本做CT扫描和Mimics建模, 在3D虚拟模型上从跟骨前部外侧壁每个区分别向载距突组配1枚螺钉, 其中S1和S2靶点是载距突内侧前段与中段交点P1, S3和S4靶点是中段与后段交点P2, 观察螺钉是否位于骨性通道内。回顾性分析2017年1月至2021年1月徐州医科大学附属宿迁医院收治的72例Sanders Ⅱ、Ⅲ型跟骨骨折患者资料, 根据不同的载距突置钉法把患者分为解剖分区组和3D打印组。解剖分区组32例, 男25例, 女7例;年龄24～60岁, 基于解剖分区法置钉。3D打印组40例, 男31例, 女9例;年龄25～58岁, 采用3D打印辅助置钉。比较解剖分区组置钉参数与实际值的差异, 比较两组间置钉总数、平均置钉数、螺钉分布和置钉准确率。结果在标本上从S1和S2向P1、S3和S4向P2虚拟置钉, 螺...     

丹参酮IIA通过PKC/Cx43通路减轻大鼠心肌缺血再灌注致心律失常

目的 探讨丹参酮II_A（TA）对再灌注致心律失常的改善作用及机制。方法 取60只SD大鼠随机分为6组：对照组，模型组，TA低、高剂量（10、20 mg·^kg-1）组，蛋白激酶C （PKC）激活剂PMA （5 mg·^kg-1）组，TA （20 mg·^kg-1）联合PKC抑制剂Rottlerin （5 mg·^kg-1）组，每组10只。构建SD大鼠心肌缺血再灌注（I/R）模型，缺血30 min再灌注30 min；再灌注期间记录各组小鼠Ⅱ导联心电图并对再灌注后心律失常严重性进行评分；再灌注结束后，取颈静脉血采用试剂盒检测心肌损伤指标肌酸激酶同工酶（CK-MB）、乳酸脱氢酶（LDH）、天冬氨酸转氨酶（AST）和心肌肌钙蛋白（cTnT）水平；取左心室心脏组织，使用试剂盒检测丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性，实时荧光定量PCR（qRT-PCR）法检测PKC、缝隙连接蛋白43（Cx43）mRNA表达，Western blotting法检测PKC、Cx43蛋白表达水平和磷酸化水平。结果 与模型组比较，TA 2个剂量组和PKC激活剂PMA组CK-MB、LDH、AST、cTnT、MDA水平均显著降低，SOD活性显著升高，室性早搏（PVB）次数、室性心动过速（VT）次数和持续时间以及心室颤动（VF）次数和持续时间显著减少，心律失常评分显著降低，差异均有统计学意义（P＜0.05、0.01、0.001） ；而TA联合PKC抑制剂组显著削弱TA的作用（P＜0.05、0.01、0.001） ；与模型组相比，TA 2个剂量组和PMA组Cx43 mRNA表达和磷酸化水平显著升高（P＜0.01、0.001） ，而PKC抑制剂使TA的作用显著减弱（P＜0.05、0.001）。结论 TA通过激活PKC调控Cx43表达和磷酸化而改善再灌注后心律失常，减轻心肌I/R损伤。     

nNOS抑制剂亚胺基烯丁基-L-鸟氨酸对心肌缺血再灌注损伤的影响及机制

目的 探讨nNOS选择性抑制剂亚胺基烯丁基-L-鸟氨酸（L-VNIO）对心肌缺血再灌注（I/R）损伤的影响及机制。方法 构建SD大鼠离体心脏I/R模型和H9c2细胞缺氧/复氧（H/R）模型；nNOS抑制剂L-VNIO（10 μmol·L^-1）持续给药整个再灌注或复氧过程。TTC染色测定心肌梗死面积；流式细胞术检测H9c2细胞凋亡率；Fluo-3/AM Ca²⁺荧光探针通过流式细胞仪检测H9c2细胞内Ca²⁺浓度；试剂盒法测定离体心脏灌流液乳酸脱氢酶（LDH）、丙二醛（MDA）水平以及H9c2细胞MDA水平和超氧化物歧化酶（SOD）活性；离体心脏提取肌浆网，试剂盒法检测肌浆网Ca²⁺-ATP酶（SERCA）活性，Western blotting检测肌浆网SERCA蛋白表达；Western blotting检测离体心脏中受磷蛋白（PLB）和兰尼碱受体2（RyR2）蛋白表达水平和磷酸化水平。结果 与I/R或H/R模型组相比，L-VNIO显著降低细胞凋亡率，减少心肌梗死面积，降低LDH、MDA水平，提高SOD活性，差异均有统计学意义（P<0.05）；此外，与I/R或H/R模型组相比，L-VNIO组明显降低细胞内Ca²⁺超载，增高PLB磷酸化水平，降低RyR2磷酸化水平，增强SERCA活性（P<0.05）。结论 nNOS抑制剂L-VNIO可以减轻I/R损伤，机制与调节Ca²⁺转运相关蛋白而降低I/R引起的Ca²⁺超载相关。     

An applied research on precise sustentacular screw placement based on anatomical division of the anterior lateral wall of calcaneus and the sustentaculum tali北大核心CSCD

Objective To evaluate our novel path based on anatomical division of the anterior lateral wall of calcaneus and the sustentaculum tali for precise sustentacular screw placement in the surgical treatment of calcaneal fractures of Sanders types Ⅱ and Ⅲ. Methods The anterior lateral wall of the calcaneus was divided into the anterior-superior zone S1, the anterior-inferior zone S2, the posterior-superior zone S3 and the posterior-inferior zone S4 for demarcation of the screw insertion points by our method of Four Zones, and into the front, middle and rear sections by our method of Three Sections for demarcation of the screw target points. The specimens were scanned by CT and modeled by Mimics. On the 3D virtual model of the calcaneus, one screw was placed from each zone of the anterior lateral wall of the calcaneus to the sustentaculum tali body. The screw placement target for S1 and S2 was the medial intersection point P1 of the front and middle sections of the sustentaculum tali, and that for S3 and S4 was the medial intersection point P2 of the middle and rear sections of the sustentaculum tali. It was observed whether the screws were placed in the bone channel. A total of 72 patients were included who had been admitted to Department of Orthopaedics, Suqian Hospital Affiliated to Xuzhou Medical University for calcaneal fractures of Sanders types Ⅱ and Ⅲ from January 2017 to January 2021. They were divided into an anatomical division group and a 3D printing group according to their screw placement method for the sustentaculum tali. In the anatomical division group of 32 patients subjected to screw placement based on our anatomical division, there were 25 males and 7 females, aged from 24 to 60 years; in the 3D printing group of 40 patients subjected to screw placement assisted by 3D printing, there were 31 males and 9 females, aged from 25 to 58 years. The disparities between the parameters of sustentacular screw placement and the actual values were compared in the anatomical division group, and the total number of screws, screws on average, distribution of screws, and accuracy of screw placement were compared between the 2 groups. Results All the screws which were virtually placed in the specimens of the calcaneus from S1 and S2 to P1 and from S3 and S4 to P2 passed through the bony channel, with no perforation into the tarsal sinus. There was no significant difference in the general date between the anatomical division group and the 3D printing group, showing they were comparable (P > 0.05). In the anatomical division group, a total of 52 screws were placed to the sustentaculum tali with an average of (1.63 ± 0.48) screws per patient, and 2 screws were placed in 20 patients, yielding an accuracy rate of screw placement of 92.3% (48/52). There were no statistically significant differences between the parameters and the actual values of screw placement in the anatomical division group (P > 0.05). In the 3D printing group, a total of 63 screws were placed to the sustentaculum tali with an average of (1.58 ± 0.49) screws per patient, and 2 screws were placed in 23 patients, yielding an accuracy rate of screw placement of 93.7% (59/63). There were no significant differences in the above comparisons between the anatomical division group and the 3D printing group (P > 0.05). Conclusion In the surgical treatment of calcaneal fractures of Sanders types Ⅱ and Ⅲ, the sustentacular screw placement based on our anatomical division of the anterior lateral wall of the calcaneus and the sustentaculum tali can lead to similar clinical accuracy as 3D printing-assisted screw placement does. © 2022 Chinese Journal of Orthopaedic Trauma. All rights reserved.