水中大鼠尸体软组织生物力学性状及脏器量化病理形态时序性变化的实验研究

发布时间：2018-06-13 15:55

本文选题：水尸 + 死亡时间　；参考：《汕头大学》2008年硕士论文

【摘要】： 背景与目的死亡时间( Postmortem Interval, PMI)推断是法医学界研究的重点和难点,其对凶犯的确定、刑事案件的侦破,以及死亡医疗纠纷,甚至遗产继承的仲裁等司法审判实践有着非常重要的意义。传统推断PMI的方法已有许多研究,包括根据早期尸体现象、胃内容物消化程度等多种方法推断早期PMI;根据尸体腐败程度、蝇蛆生长规律等推断晚期PMI。但这些方法由于影响因素多、检测方法繁杂等问题,均存在较大的误差。近年来,较多研究利用DNA和蛋白质降解的分子生物学技术推断PMI,认为是比较准确可靠的方法,但其依然受到自身和外界多重因素的影响,且操作复杂,尚处于研究阶段。 PMI推断的研究,实验条件的控制非常重要。本实验在课题组其他成员的空气中大鼠PMI研究基础上,以水中尸体为研究对象,控制温度、空气流通度等实验条件,期望探讨水中尸体软组织的生物力学性状的时序性变化与PMI关系的规律,将法医生物力学理论和技术引入到PMI推断中,进一步丰富法医生物力学(forensic biomechanism)的研究内容和开拓PMI推断新技术方法。同时,本实验利用CDIA技术,观测常规HE染色的肝细胞病理图像并进行体视学分析与量化处理,结合水中尸体主要脏器的病理形态的系统观察,期望为PMI推断提供新思路和参考依据。材料与方法清洁级健康雄性SD大鼠80只,3～3.5月龄,体重250-300g,颈脱位法处死,按死后不同时间点随机分为0h、6h、12h、18h、24h、30h、36h、42h、48h、60h、72h、96h、120h、144h、168h、192h共16组,每组5只。立即放置于2/3满在GXZ型智能光照培养箱中25±0.5℃恒温的自来水塑料桶,让其自然腐败,分别于上述时间点提取胸部正中皮肤1×4cm2、腹壁白线右侧1cm处腹壁肌肉1×4cm2、直肠上4～10cm处结肠、胃下6～12cm处小肠进行生物力学指标检测,每个时间点5只,检测其极限载荷、最大应力、应变等软组织生物力学指标。同时选取0h、12h、24h、36h、48h、72h脑、心、肝、肾、肺切片HE染色并进行镜下观察,观察各组织自溶腐败的形态学变化,并对大鼠肝细胞进行病理学图像体视学分析和量化处理,检测肝细胞的核面积、核浆比、核浆光密度比和核异形指数,用SPSS软件进行统计学处理和分析,探讨其形态时序性变化规律及其与PMI的关系。结果 1主要脏器组织形态学改变水中大鼠尸体经尸僵、腐败静脉网、尸绿、腹部膨隆至塌陷约需8天。HE染色镜下观察,各脏器均呈现时序性变化。脑0-24h神经元细胞核固缩,24-48h核扩大至脑液化。心0-24h肌浆肿胀、肌间隙增宽,24-48h肌浆模糊、断裂,肌细胞核明显减少,48-72h心肌细胞核消失;肝0-24h肝细胞肿胀,24-48h肝细胞间隙变小至边界不清,核固缩、碎裂,48-72h仅残留少量细胞核碎片。肾0-24h近曲小管上皮细胞嗜酸性增强,24-72h肾小管、肾小球细胞核相继固缩、碎裂、溶解消失,96h细胞核完全消失。肺0-24h肺泡上皮细胞胞浆淡染,24-48h肺泡上皮细胞核固缩、碎裂、明显减少,48-72h肺泡腔浆液淤积至肺组织完全破碎、结沟不清。各脏器比较,脑自溶、腐败最快,肝、心、肺其次,肾自溶腐败最慢。其中,脑48h即已液化无法取材切片,肝、心、肺72h组织结构基本消失,肾组织自溶腐败速度较慢,96h细胞核基本消失,120h组织轮廓不清。 2生物力学测试与分析结果 2.1极限载荷各组织极限载荷均值大小排序为:皮肤(14.71N)大肠(3.96N)肌肉(3.85N)血管(1.97N)小肠(1.27N)。各组织总体均呈死后时序性下降趋势,下降速度在各时间点存在差异。皮肤0-18h下降迅速(直线回归方程为YPMI=33.087-1.3121XML,r=-0.999),相邻点间差异显著(P0.01),18-36h、96-168h呈缓慢下降趋势(YPMI=120.153-9.009XML,r=-0.965;YPMI=13.822-0.0485XML,r=-0.941),P0.05。36-96h、168-192h相邻时间点差别不明显(P0.05)。肌肉0-24h、96-168h下降趋势明显,其直线回归方程分别为YPMI=42.914-4.9861XML,r=-0.989;YPMI=177.6-24.289XML,r=-0.970。24-96h为“平台期”,168-192h比较差异不明显(P0.05)。大肠0-36h、72-192h(YPMI=66.238-8.6983XML,r=-0.981;YPMI=225.14-41.488XML,r=-0.978)下降趋势明显(P0.05),36-72h为“平台期”。小肠0-18h(YPMI=53.903-27.422XML,r=-0.968)、120-192h(YPMI=350.55-200.57XML,r=-0.986)下降趋势明显,18-120h为“平台期”(P0.05)。血管全程变化趋势不明显。 2.2应变血管应变最大为3.96,但变化趋势不明显。小肠最小为0.34。皮肤、肌肉、大肠、小肠总体均呈下降趋势。皮肤0-48h下降迅速,YPMI =88.894-77.665XSR,r=-0.962(P0.01)。48-192h为“平台期”。肌肉0-30h下降迅速,YPMI =52.112-41.544 XSR,r=-0.970(P0.01),30-192h为“平台期”(P0.05)。大肠0-24h下降迅速,YPMI=59.106-55.031XSR,r=-0.962。24-72h为“平台期”,72-192h下降趋势明显(P0.01),YPMI=307.03-346.59 XSR,r=-0.993。小肠0-24h下降迅速,YPMI =56.758-87.079 XSR,r=-0.949(P0.01),24h-192h为”平台期”。 3肝脏细胞病理图像量化处理肝细胞核面积各时间段的差异没有统计学意义(P0.05)。肝细胞核浆比呈下降趋势,其直线回归方程为YPMI=0.3683-0.0045XRKC,r=-0.9361。其中12-24h下降速率最大,0-12h、24-72h下降速度较慢。各相邻时间点比较差异有统计学意义(P0.05)。核浆光密度比,0-36h呈逐渐上升趋势(Y=69.751X-78.117,r=0.982),36-72h呈逐渐下降趋势(Y=198.44-97.676X,r=-0.999),各相邻时间点比较差异有统计学意义(P0.05)。异形指数呈上升趋势(YPMI=30.177XRKC-31.707,r=0.989),12-36h上升速度最大,其次为0-12h(P0.05),48-72h差异不明显(P0.05)。结论 1、水尸各器官组织形态的时序性变化与PMI之间存在明显的相关性,其主要为自溶和腐败的结果,与空气中尸体比较,自溶和腐败约晚12小时,提示日常法医病理学检验时,应注意鉴别生前弥漫性病变与死后自溶腐败性变化,还应综合考虑尸体腐败环境。水尸72h内为自溶、腐败高峰期,应争取尽早尸检或冷冻保存尸体。 2、水尸皮肤、肌肉、小肠和结肠各器官组织的生物力学性状存在时序性变化规律,特别是各自均存在一段明显的线性相关的“窗口期”和相互弥补性,提示软组织生物力学指标及其检测方法可以作为推断死亡时间的一种简便、客观、量化的检测手段。 3、病理学图像量化分析技术检测的常规HE组织细胞各种描述指标,可以量化地反映死后组织细胞自溶腐败的形态学变化程度,与PMI之间存在明显的相关性,特别是组织细胞结构的自身比较的相对性指标,可以避免不同制片、染色效果的影响,更客观地反应病变情况和分级标准,为量化病理学提供了新的思路。
[Abstract]:Background and Purpose

In recent years , many researches have been made on the methods of estimating PMI by means of molecular biology techniques such as early corpse phenomenon , gastric contents digestion degree and so on .

Based on the study of PMI , it is very important for the control of the experimental conditions . In this experiment , based on the study of the PMI in the air of the other members of the study group , it is expected to study the temporal variation of the biomechanical properties of the soft tissue in the water and the law of PMI , and further enrich the research content of the forensic biomechanics theory and the technique . At the same time , the present experiment uses the CDIA technique to observe the pathological image of liver cells stained by conventional HE and the systematic observation of the pathological morphology of the main organs of the corpse in water .

Materials and Methods

The rats were randomly divided into 2 / 3 hours , 12 h , 18 h , 24 h , 30 h , 36 h , 42 h , 48 h , 60 h , 72 h , 42 h , 48 h , 60 h , 72 h , 96 h , 120 h , 48 h , 48 h , 72 h , 96 h , 120 h , 48 h , 48 h , 72 h , 24 h , 48 h , 60 h , 72 h , 96 h , 120 h , 48 h , 48 h , 72 h , 24 h , 48 h , 48 h , 72 h , 96 h , 120 h , 48 h , 48 h , 72 h . SPSS software was used for statistical processing and analysis , and the regularity of its morphology and its relationship with PMI were discussed .

Results

1 . Morphological changes of major organs of organs

The results showed that after 24 - 48 h , the nuclei of the alveolar epithelial cells disappeared . The results showed that the nuclei of the cells of 0 - 24 h after 24 - 48 h could not be removed . The results showed that the nuclei of liver , heart , and lung had disappeared after 24 - 48 h .

2 biomechanical testing and analysis results

2.1 Ultimate Load

The mean size of the limit load of each tissue was ordered as : skin ( 14.71N ) large intestine ( 3.96N ) muscle ( 3.85N ) blood vessel ( 1.97N ) small intestine ( 1.27N ) .

There was no significant difference between the two adjacent time points ( P0.05 ) . The descending trend of YPMI = 42.914 - 4.9861XML , r = - 0.989 ; YPMI = 177.6 - 24.289XML , r = - 0.970 . 24 - 96h , r = - 0.978 ;

2.2 Strain

The maximum blood vessel strain was 3.96 , but the trend was not obvious . The small intestine had a minimum of 0.34 . Skin , muscle , large intestine and small intestine showed a decreasing trend .

The decrease of 0 - 30h decreased rapidly , YPMI = 52.112 - 41.544 XSR , r = - 0.970 ( P0.01 ) , 30 - 192h as " plateau phase " ( P0.05 ) . The descending trend of intestine 0 - 24h was rapid , YPMI = 59.106 - 55.079 XSR , r = - 0.993 . Small intestine decreased rapidly from 0 - 24h , YPMI = - 0.949 ( P0.01 ) , 24h - 192h was " plateau phase " .

Quantitative treatment of pathological image of liver cells

There was no significant difference in the area of liver cell nuclear area ( P0.05 ) .

The linear regression equation was YPMI = 0.3683 - 0.0045XrKC , r = - 0.9361 . The descending rate of 12 - 24h was the highest , and the rate of decline was slower between 0 - 12h and 24 - 72h .

The optical density ratio of nuclear plasm was 0 - 36h ( Y = 69.751X - 78.117 , r = 0.982 ) and 36 - 72h ( Y = 198.44 - 97.676X , r = - 0.999 ) .

The trend of abnormal index was ( YPMI = 30.177XrKC - 31.707 , r = 0.989 ) , the rate of rising of 12 - 36h was the biggest , followed by 0 - 12h ( P0.05 ) , the difference between 48 - 72h was not obvious ( P0.05 ) .

Conclusion

1 . There is a significant correlation between the temporal variation of tissue morphology and PMI , which is mainly the result of autolysis and corruption . When compared with the corpse in the air , self - dissolution and corruption are about 12 hours later , it is suggested that in the course of routine forensic pathology examination , it should be paid to the identification of the corrupt environment of the corpse before and after death .

2 . The biomechanical properties of the tissues of the skin , muscle , the small intestine and the colon of the water bodies are regularly changed , especially the " window period " and the mutual compensation of the obvious linear correlation , suggesting that the biomechanical indexes of soft tissues and their detection methods can be used as a simple , objective and quantitative detection means for estimating the dead time .

3 . Various description indexes of conventional HE tissue cells detected by pathological image quantitative analysis technique can quantitatively reflect the morphological change degree of self - dissolution and corruption of tissue cells after death , and have obvious correlation with PMI , especially the relative indexes of tissue cell structure ' s own comparison , so as to avoid the influence of different tabs and staining effect , more objectively reflect the pathological condition and grading standard , and provide a new idea for quantitative pathology .
【学位授予单位】：汕头大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：D919.1

【引证文献】