电击死后大鼠骨骼肌MuRF1表达的法医学研究

发布时间：2018-01-21 08:22

本文关键词： 法医病理学电击死骨骼肌 MuRF1　出处：《重庆医科大学》2013年硕士论文　论文类型：学位论文

【摘要】：目的：电击死和他杀伪装电击是法医学实践中常见的案件类型之一,但实际检案过程中,法医工作者对其诊断仍没有统一的标准,尤其是对无电流斑情况的死因推断或特殊情况的水中电击。许多学者从电击死后各个组织器官的形态学及分子水平进行了研究。当电击案件中无电流斑形成时,组织学改变不明显时,电击死后根据骨骼肌的变化推断早期死亡时间鲜有报告。我们设计了以下实验检测通电肢体骨骼肌MuRF1的表达情况,以期鉴别生前电击死和死后电击、生前电击死和死后电击早期死亡时间的推断、电损伤对不同骨骼肌类型的影响。方法：60只健康的Wistar大鼠,分成电击死组、死后电击组、空白对照组,每组20只。电击死组大鼠用220v交流电的两极分别连接右前肢与左后肢,通电90s致死,于电击死后0h、1h、3h、6h取材；死后电击组大鼠采用颈椎脱臼法处死后,分别于0h、1h、3h、6h电击90s取材；空白对照组大鼠直接颈椎脱臼法处死,不进行电击,于死后0h、1h、3h、6h取材。取左后肢腓肠肌、胫骨前肌,进行HE染色、免疫组化染色和实时荧光定量PCR处理。结果：1、HE染色结果电击死组：可见骨骼肌细胞呈空泡样改变、灶状变性、坏死；部分细胞核极化、部份骨骼肌细胞断裂、波浪样改变,部分骨骼肌横纹不清；胞浆凝聚、均质化、嗜酸性变；胞核固缩、深染、扭曲,部分核伸长；骨骼肌间细小血管扩张,红细胞聚集,血管内皮细胞肿胀、核深染。随着死亡时间的延长,细胞溶解、坏死加重,可见嗜酸性粒细胞聚集。死后电击组：可见骨骼肌细胞灶状坏死；骨骼肌细胞溶解、断裂骨骼肌细胞浊肿显著；胞核扭曲、固缩、深染,部分核伸长；骨骼肌细胞内肌丝间隙增宽明显；嗜酸性粒细胞浸润。空白对照组：可见骨骼肌细胞变性、坏死；胞浆凝聚、均质化、嗜酸性；胞核固缩、深染；血管内皮细胞肿胀；骨骼肌间细小血管扩张,红细胞聚集。 2、免疫组化染色结果电击死组通电肢体即刻腓肠肌胞浆可见棕黄色颗粒聚集,随着时间的推移棕黄色颗粒逐渐减弱；死后电击组通电肢体即刻腓肠肌可见胞浆棕黄色颗粒聚集,平均密度比电击死组低；电击死组通电肢体即刻胫骨前肌可见胞浆棕黄色颗粒聚集,1h平均密度达峰值,随后降低；死后电击组通电肢体即刻胫骨前肌可见胞浆棕黄色颗粒,与电击死组胫骨前肌的变化趋势相同,平均密度比电击死组低；电击死组、死后电击组、空白对照组通电肢体胫骨前肌胞浆棕黄色颗粒平均密度大于腓肠肌。 3、RT-PCR定量结果电击死组大鼠左后肢腓肠肌MuRF1-mRNA表达量于死后即刻升高,1h、3h下降,与空白对照组相比有显著差异,6h低于空白对照组无显著意义；电击死组大鼠左后肢胫骨前肌MuRF1-mRNA表达量于死后即刻升高,1h达峰值,3h开始降低,与空白对照组相比均有显著差异；死后电击组左后肢腓肠肌、胫骨前肌较空白对照组高,但升高不如电击死组明显；电击死组、死后电击组左后肢胫骨前肌MuRF1-mRNA含量均较腓肠肌高。结论：1、MuRF1可为电击死后早期死亡时间的推断提供一定的参考依据。 2、MuRF1可作为生前电击死与他杀死后伪装电击鉴别的辅助指标之一。 3、胫骨前肌、腓肠肌对电击反应不同,胫骨前肌更易受电损伤影响。
[Abstract]:Objective: electrocution and homicide disguise shock is one of the most common types of cases in forensic medicine, but the case inspection process, forensic workers still no unified standard for the diagnosis, especially the shock for non current marks of autopsy or special conditions of water. Many scholars from morphological and molecular level of various tissues and organs electrocution was studied. When the shock cases without current spot formation, the histologic change is not obvious, after the early death of electrocution according to the changes of the skeletal muscles to infer the time little report. We designed the following experiments to detect expression of electrified limb skeletal muscle MuRF1, in order to distinguish antemortem death and death after the shock, before and after the death of electrocution shock early estimation of the death time, electrical injury effects of different skeletal muscle types.
Methods: 60 healthy Wistar rats were divided into electrocution group, after the death of shock group, blank control group, 20 rats in each group. Electrocution group rats right forelimb and left hind limb connected respectively with 220V AC power poles, 90s death, in shock after the death of 0h, 1H, 3h, 6h materials; after the death of electric shock rats were killed by cervical dislocation, respectively in 0h, 1H, 3h, 90s based 6h shock; blank control group rats were sacrificed by cervical dislocation, not to shock, after the death of 0h, 1H, 3h, 6h respectively. Take the left hindlimb gastrocnemius and tibialis anterior muscle. HE staining, immunohistochemical staining and real-time fluorescence quantitative PCR.
Results: 1, HE staining results
Electrocution group: vacuolar changes were seen in skeletal muscle cells, focal degeneration and necrosis; nuclear polarization, part of skeletal muscle cells were broken, wave like change, some skeletal muscle stripes is unclear; condensation of cytoplasm, homogenization, eosinophilic change; nuclear pyknosis, anachromasis, twist, nuclear elongation; small blood vessels expand, erythrocyte aggregation, endothelial cell swelling, nuclear stained. Along with the extension of the time of death, cell lysis, necrosis increased, visible accumulation of eosinophils.
Postmortem shock group: skeletal muscle cells showed focal necrosis, skeletal muscle cells dissolved and broken, skeletal muscle cells were turbid and swollen, nuclei were twisted, compressed, deeply stained, and some nuclei elongated.
Blank control group: skeletal muscle cell degeneration and necrosis, cytoplasmic condensation, homogenization, eosinophilia, nuclear condensation, deep staining, vascular endothelial cell swelling, skeletal muscle microvascular dilatation, red blood cell aggregation.
2, immunohistochemical staining results
Electrocution group power cell gastrocnemius limb immediately visible Brown particle slurry, with the passage of time Tan particles gradually weakened; after the death of the group of electrical shock rats' gastrocnemius muscle's cytoplasmic Brown particle, the average density was lower than the electrocution; electrocution group electrified limb immediately anterior tibial muscle visible cytoplasmic Brown particle, the average density of 1H reached the peak, then decreased; the group of electrical shock after death the body immediately the tibialis anterior muscle's cytoplasmic brown granules, and the same trend of electrocution group of the tibialis anterior muscle group is lower than the average density of electrocution; electrocution group, after the death of shock group, blank the control group average density of electrified limb anterior tibial muscle cytoplasm brown granules than gastrocnemius.
3, RT-PCR quantitative results
Electrocution group rats left hindlimb gastrocnemius MuRF1-mRNA expression increased, immediately after the death of 1H, 3h decreased, with significant difference compared with the control group, no significant 6h lower than the blank control group; electrocution group rats left hindlimb tibialis anterior muscle MuRF1-mRNA expression immediately after the death of the high rise, reached the peak at 1H. 3h, began to decrease, compared with the blank control group had significant difference; after the death of shock group left hindlimb gastrocnemius and tibialis anterior muscle than the control group, but higher than electrocution group significantly; electrocution group, shock group after the death of the left hind limb of tibialis anterior muscle MuRF1-mRNA content were compared with gastrocnemius.
Conclusion: 1, MuRF1 can provide some reference for the early death time of electric shock after death.
2, MuRF1 can be used as one of the auxiliary indicators for the identification of pre shock and kills of camouflage electric shock.
3, the anterior tibial muscle and the gastrocnemius are different to the electric shock, and the anterior tibial muscle is more susceptible to electrical damage.

【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：D919.4

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