电击伤（死）后心肌PEG-3表达的法医学研究

发布时间：2018-05-24 16:02

本文选题：电损伤 + 电击伤　；参考：《重庆医科大学》2007年硕士论文

【摘要】： 目的:电击伤(electrical injury)和电击死(electrouction)是法医实践工作中常遇的案例,但其诊断有一定的困难,因此对电击伤和电击死的研究具有重要意义。尽管已经有很多学者对其进行了大量的相关研究,但是在没有典型的电击损伤标志(如皮肤电流斑、金属化)出现时仍然没有哪一个指标可以直接对电击伤和电击死进行诊断。在实际工作中,研究发现只有约1/3的案例出现典型的电击标志,故对未出现典型电击标志的疑似电击伤和电击死的诊断尤为重要。有文献报道在对电击伤进行心脏组织基因芯片研究时发现PEG-3在电击伤案例中有显著增高,本实验采用了免疫组织化学和原位杂交的方法,旨在观察: 1. PEG-3在电击伤和电击死中的诊断价值; 2. PEG-3在电击伤后的时间表达相关性; 3. PEG-3在死后电击和电击死中的表达情况。方法:将250-300g的Wister大鼠分成随机分成两大组:阴性对照组和实验组,阴性对照组又按照断颈处死后取材时间的不同分为6个亚组(0 h, 0.5h, 1h, 3h, 6h, 12h)实验组又分为3个小组,即:电击伤组(0h, 3h, 6h, 12h, 24h, 3d, 6d, 12d)、电击死组(0h, 1h, 3h, 6h, 12h )和死后电击组(0 h, 0.5h, 1h, 3h),共计23组(n=3)。建模的方法分别是: 1.阴性对照组采用断颈处死; 2.电击伤组是将老鼠电击30秒;电击死组则是将老鼠直接电死;死后电击组是在断颈处死后分别于相应的时间进行电击,电击时间60s;模型建立后分别在相应的时间取心脏组织(取材的部位均为左心室前壁中央部)。进行HE、免疫组织化学和原位杂交染色,然后进行半定量分析。结果:1.HE染色可见电击伤组在3-6h期间,心肌多灶性坏死,广泛心肌断裂、缺血,部分心肌细胞呈波纹状排列及收缩带坏死;心肌胞浆凝聚、均质变和嗜酸变,部分心肌横纹不清,胞核固缩、深染、扭曲,部分核伸长,部分核染色质边集、核膜增厚、呈空泡状;心肌间隙增宽,水肿,部分区域散在出血;细小血管扩张,红细胞聚集,血管内皮细胞细胞核固缩、深染,平滑肌变性。12h-3d期间,心肌变性坏死的范围扩大,心肌细胞浑浊肿胀更加明显,心肌细胞内小肌束间隙增宽使心肌横断面呈筛状;心肌细胞横纹不清,部分心肌细胞呈肌溶解、肌浆淡染,部分心肌细胞核消失;心肌间细小血管扩张,内皮细胞肿胀、坏死、脱落,平滑肌层疏松肿胀,大量红细胞黏附于血管壁,管腔内嗜中性粒细胞聚集,仅个别炎症细胞游出血管外。6d-12d期间,心肌变性坏死范围仍在扩大,大片心肌溶解坏死,肌间隙明显增宽。电击死组也可以看到心肌细胞的变性坏死,死后电击组只在死后即刻电击可以看到心肌的缺血性改变,而阴性对照组则未见异常。 2.免疫组织化学染色和原位杂交染色可见直接电击死组和电击伤组心肌细胞内有很强的阳性染色,位于肌浆内,在电击伤后即刻即开始增加,在12h时达到高峰,而后逐渐减少,在12d时其值仍高于对照组,但与对照组接近;电击致死组也呈强阳性表达,在电击致死后即刻表达就开始增加,3h时达到高峰,而后逐渐减少,12h时其值仍高于对照组,但与对照组接近;而阴性对照组和死后电击组只有极其微弱的阳性染色。以上这一变化规律可推断心肌电损伤所经过的时间。结论:在电击伤和直接电击死早期即可见大量的心肌纤维断裂,胞浆凝聚以及嗜酸性变;细胞核的固缩、深染、扭曲以及部分核伸长和空泡样变化,这些改变与急性心肌梗死及其他心肌疾病、损伤的病理改变不尽相同,说明这些损伤是电流作用的结果。免疫组化和原位杂交的强阳性染色也说明电流对心肌造成了损伤. PEG-3是与细胞核损伤相关的基因,在心肌电损伤和电击致死的早期即表达增高,而在其他心肌损伤及非肿瘤性心肌疾病中很少在早期出现高表达,这提示PEG-3有助于诊断心肌电损伤,可将其作为一个诊断早期心肌电损伤的指标。此外,还发现其在电击伤和直接电击死后不同时间的表达有一定的规律,根据这一规律的变化可推断心肌电击伤(死)的时间。而在死后电击则只有弱表达,根据这点可以将死后电击和电击致死进行区分。
[Abstract]:Objective: electrical injury (electrical injury) and electric shock (electrouction) are common cases in forensic practice, but their diagnosis is difficult. Therefore, it is of great significance for the study of electrical injury and electric shock death. No one index, such as skin current spots, metallization, can be used to diagnose electrical injury and shock death. In actual work, only about 1/3 cases are found to have typical electric shock signs, so it is particularly important for the diagnosis of suspected electrical injury and shock death without typical electric shock signs. It was found that PEG-3 was significantly increased in the case of electrical injury when the cardiac tissue microarray was studied. This experiment was conducted by immunohistochemistry and in situ hybridization.
1. the diagnostic value of PEG-3 in electrical injury and electrocution.
2. PEG-3 was associated with the time after electrical injury.
3. the expression of PEG-3 in electrocution and electrocution after death.
Methods: the Wister rats of 250-300g were divided into two groups randomly: negative control group and experimental group. The negative control group was divided into 6 subgroups (0 h, 0.5h, 1H, 3h, 6h, 12h) and divided into 3 groups according to the difference of the time after the death of the neck. The experimental group was divided into 3 groups, namely, the electrical injury group (0h, 3h, 6h, 12h, 12h, 12h, 6h, etc.) 6h (12h) and postmortem shock group (0 h, 0.5h, 1H, 3H), a total of 23 groups (n=3).
1. the negative control group was executed with broken neck.
The 2. electric injury group was a mouse electric shock for 30 seconds; the electric shock group was killed directly by the mouse; after the death, the electric shock group was struck at the corresponding time after the death of the neck, and the electric shock time was 60s. After the model was established, the heart tissue was taken at the corresponding time (the central part of the left ventricle was in the central part of the left ventricle). In situ hybridization, and then semi quantitative analysis.
Results: 1.HE staining showed multifocal necrosis of myocardium in the electrical injury group during 3-6h, extensive myocardial rupture, ischemia, partial myocardial cells with ripple arrangement and contraction zone necrosis, myocardial cytoplasm condensation, homogenization and eosinophilia, partial myocardial transmutation, nuclear condensation, deep staining, distortion, partial nucleus elongation, partial nucleus chromatin set and thickening of nuclear membrane. The myocytes were vacuolated; the interventricular space was broadened, edema, and partial areas were scattered; the small vessels dilated, the red blood cells gathered, the vascular endothelial cell nuclear condensation, the deep staining and the smooth muscle degeneration.12h-3d, the range of myocardial degeneration and necrosis expanded, the turbid swelling of the cardiac myocytes was more obvious, and the widening of the small myoplastic space within the myocardial cells made the transverse section of the myocardium present the cross section of the myocardium. Sieves; myocardial cells were indistinct, some of the myocytes were myolysis, myoplasm was pale, and some of the nucleus of the myocardium disappeared; the small blood vessels were dilated, the endothelial cells swelled, necrotic, exfoliated, the smooth muscle layer was loose and swollen, a large number of red cells adhered to the vascular wall, the neutrophils gathered in the lumen, and only a few inflammatory cells swam out of the extravascular.6d-1 During the period of 2D, the extent of myocardial degeneration and necrosis was still enlarged, large myocardial infarction was dissolved and necrotic, and the muscle space was broadened obviously. The necrosis of myocardial cells could be seen in the death group of electric shock. The ischemic changes of myocardium could be seen in the post death electric shock group only after death, but the negative control group had no abnormal.
2. immuno histochemical staining and in situ hybridization showed that there was a strong positive staining in the cardiac myocytes of the direct electric shock group and the electric injury group. It was located in the muscular plasma and increased immediately after the electrical injury. It reached the peak at 12h and then decreased gradually. At 12D, its value was still higher than that of the control group, but it was close to the control group; and the death group in the electric shock was also present. The expression of strong positive expression began to increase immediately after the death of electric shock, and reached the peak at the time of 3H, and then decreased gradually. The value of 12h was still higher than that of the control group, but it was close to the control group, while the negative control group and the post death electric shock group had only a very weak positive staining. The above change rules could deduce the time of myocardial electrical injury.
Conclusions: in the early stages of electrical injury and direct shock death, a large number of myocardial fibers, cytoplasm agglomerates and eosinophilic changes are visible, nuclear condensation, deep staining, distortion, and partial nuclear elongation and vacuolating change are different from the pathological changes of acute myocardial infarction and other myocardial diseases and injury, indicating that these injuries are current. The strong positive staining of immunohistochemistry and in situ hybridization also showed that the current caused damage to the myocardium.
PEG-3 is a gene associated with nuclear damage, which is increased in the early stage of myocardial electrical injury and death by electric shock, and is rarely expressed in the early stages of other myocardial injury and non tumor myocardium diseases. This suggests that PEG-3 can help diagnose electrical injury of the myocardium, and can be used as an indicator for the diagnosis of early myocardial damage. It is found that there is a certain regularity in the expression of electric shock and direct electric shock at different time after death. The time of myocardial electrical injury (death) can be deducted according to the change of the law. And the electric shock is only weak after death. According to this, the electric shock and the death of electric shock can be distinguished.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：D919

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