本文選題：死亡時間 + 軟組織時序性變化��； 參考：《汕頭大學》2008年碩士論文

【摘要】： 背景與目的 早在三百多年前被譽為歐洲法醫(yī)學之父的意大利醫(yī)生Paul明確指出:死亡時間(Postmortem interval,PMI)的推斷是法醫(yī)學鑒定首先要解決的問題。準確的死亡時間的推斷在很大程度上為偵察工作提供線索、劃定偵察范圍、確定嫌疑犯或兇犯有無作案時間、或者確定案件性質、闡明作案過程均有價值。近幾十年來,國內外法醫(yī)工作在死亡時間的推斷方面使用生物學、化學、物理學、生物化學、生物物理學、免疫組織化學,分子生物學等方法取得可喜呈果。但鑒于死亡后尸體受多種因素的影響,包括自身因素和環(huán)境因素等,尤其是自溶和腐敗的影響,迄今,還沒有找到一種方法對完全推斷PMI具有相同程度的敏感性。因此,準確的死亡時間的推斷尚需綜合多種手段和方法進行綜合評估。對于死后早期時間的推斷,目前的推斷方法較多;而死后較長時間尤其是腐敗尸體死亡時間的評估方法則相對較少,推斷的誤差也相對較大,且至今尚缺乏精確而簡便的方法,因此死亡時間的評估尤其是死后較長時間的評估至今還是法醫(yī)學的難題之一。 為此,本實驗將生物力學理論和技術應用于PMI的推斷,探討了尸體軟組織的生物力學性狀的時序性變化與死亡時間的關系,進而將法醫(yī)生物力學應用到死亡時間的推斷,使法醫(yī)生物力學(forensic biomechanism)的應用進一步得到擴展和延伸。同時,本實驗運用用計算機圖像數(shù)字分析(Computer digital image analysis)技術,對肝細胞HE染色下進行病理學圖像的體視學分析與量化處理,并將其應用于法醫(yī)病理學PMI的推斷,為病理學的發(fā)展趨勢——量化病理學在法醫(yī)學的應用提供了新的思路,并進一步結合尸體主要臟器的常規(guī)病理圖片觀察,探討其與PMI的關系。 材料與方法 清潔級健康雄性SD大鼠80只,3～3.5月齡,體重250～300g,用脫頸法處死后,立即置于恒溫箱內,分0、6、12、18、24、30、36、42、48、60、72、96、120、144、168、192h時間組,提取胸部皮膚、腹壁肌肉、胸主動脈、小腸和大腸進行生物力學指標檢測,每組5只,檢測極限載荷、應力、應變等軟組織生物力學指標。同時,提取全腦、最大葉肝臟、全心、左肺最大葉、左腎進行HE切片染色和體視學觀察,觀察組織細胞的自溶和腐敗的形態(tài)學變化;并對肝細胞進行病理圖像分析和量化處理,檢測肝細胞的核面積、核漿比、核漿光密度比和核異形指數(shù),探討其與PMI的關系。 結果 1大體及鏡下改變: 大體改變:死后尸體主要經(jīng)歷了尸僵、尸綠、毛發(fā)脫落、腹部膨脹至“巨人觀”,軟化塌陷的過程,腹腔內臟器逐步液化。 鏡下改變:腦、心、肺、肝、腎等實質器官組織形態(tài)隨PMI呈一定規(guī)律性變化,腦自溶相對較快,48h即難以取出,心臟自溶速率較慢,96h仍可見心肌纖維。各組織細胞均經(jīng)歷嗜堿性逐漸減弱、嗜酸性逐漸增強的過程,細胞核染色質由逐漸聚集到最后突破核膜溶解。 2軟組織生物力學性狀 皮膚具有最大的極限載荷,平均為11.67N;小腸的極限載荷最小,平均僅為1.37N。皮膚、小腸死后18h內均呈較明顯下降趨勢(Y_(PMI)=-1.26X_(ML)+31.03,r=0.985和Y_(PMI)=-27.5X_(ML)+53.5,r=0.956)。皮膚18～36h轉呈上升趨勢,36h后呈緩慢下降趨勢,但相鄰各點差別無統(tǒng)計意義。小腸18h后無明顯變化趨勢。肌肉與大腸的規(guī)律較為相似,24h內均呈較明顯下降趨勢,相鄰各點均有統(tǒng)計意義(Y_(PMI)=-5.18X_(ML)+42.639,r=0.992和Y_(PMI)=-7.83X_(ML)+58.1,r=0.988)。之后,變化趨勢不明顯,稱之為“平臺期”。其中,肌肉24～96h呈平臺期,之后緩慢下降,但96～168h相鄰各點差別具統(tǒng)計意義(Y_(PMI)=-23.812X_(ML)173.91,r=0.97);大腸24～72h呈平臺期,之后緩慢下降(Y_(PMI)=-44.05X_(ML)+231.7,r=0.981)。血管死后變化趨勢不明顯。 血管的應變最大,平均為4.12,但變化趨勢無明顯的統(tǒng)計學意義。其他組織24h內均呈明顯下降趨勢,下降速率較快。24h后肌肉與小腸變化趨勢不明顯;皮膚24～72h呈平臺期,72h后呈現(xiàn)緩慢下降趨勢,72～96h無統(tǒng)計意義,96小時后下降趨勢具有統(tǒng)計意義;大腸與皮膚較為相似,24～72h呈現(xiàn)平臺期,72～192h呈逐漸下降趨勢(Y_(PMI)=-333X_(應變)+297.7,r=0.991),120h后各時間點的差別具有統(tǒng)計意義。 各組織的最大應力改變趨勢與極限載荷趨勢較為一致,血管仍無明顯規(guī)律,其他組織在24h內下降趨勢較明顯。24h后,除小腸未見明顯趨勢外,均有下降趨勢,但較24h內緩慢。 3肝細胞病理圖像分析的量化指標 肝細胞核面積變化不穩(wěn)定,隨PMI的變化趨勢不明顯。核漿比總體呈逐漸下降趨勢,其中,0h～36h顯著(P＜0.05)。36h～60h呈緩慢上升趨勢,但二者差別無統(tǒng)計意義(P＞0.05)。60h～72h下降明顯,有統(tǒng)計意義(P＜0.05)。核漿光密度比總體呈先上升后下降趨勢,36h內呈逐漸上升趨勢,36h達峰值,相鄰點間差別具有統(tǒng)計意義(P＜0.05):24h與36h差別明顯(P＜0.01)。36h～72h呈逐漸下降趨勢,相鄰點時間點差別均有統(tǒng)計意義。異形指數(shù)72小時內呈逐漸上升趨勢(Y_(PMI)=512.09X_(ID)-699.5,r=0.982)。 結論 1、PMI與各器官組織形態(tài)學的時序性變化之間存在較明顯的相關性。各臟器的自溶和腐敗速率不同,因此在各時段的PMI中各組織臟器存在不同的鏡下特點,根據(jù)個組織臟器的鏡下特點,可大約估算PMI,并為日常法醫(yī)病理檢案鑒別生前彌漫性病變與死后自溶腐敗性變化提供了參考依據(jù)。 2死后尸體軟組織皮膚、肌肉、大腸、小腸的極限載荷、應力、應變隨PMI的延長呈逐漸下降趨勢,且各組織在死后不同時間的下降速率不同,使得各組織在推斷PMI的“窗口期”不同,并且在一定程度存在互補性。提示軟組織生物力學指標和方法可以作為推斷死亡時間的一種簡便、客觀、量化的檢測手段。血管無明顯規(guī)律,說明血管的極限載荷及應力、應變不適合推斷PMI。 3將病理學圖像量化分析技術應用于PMI得推斷,證實了在HE染色下肝細胞的核漿比、核漿光密度比、異形指數(shù)能較好的反映肝細胞的自溶程度,其中,核漿光密度比呈現(xiàn)先上升后下降趨勢,核漿比和異形指數(shù)呈現(xiàn)線性下降趨勢,而核面積與其自溶程度無明顯的相關性。提示組織細胞自身比較的相對性指標,可以避免不同制片、染色效果的影響,更客觀地反應病變情況和分級標準,為量化病理學提供了新的思路。
[Abstract]:Background and purpose
Paul, a Italy doctor known as the father of European forensic science more than 300 years ago, made it clear that the Postmortem interval (PMI) is the first problem to be solved in forensic identification. The exact time of death provides a line to the reconnaissance work to a large extent, delineate the scope of the reconnaissance, and determine the suspect or the murderer. No case time, or the nature of the case, is of value. In recent decades, the forensic work at home and abroad has achieved good results in the use of biological, chemical, physical, biophysics, biophysics, immuno histochemistry, molecular biology and other methods to infer the time of death. But in view of the many causes of death after death. The effects of elements, including their own and environmental factors, especially the effects of autolysis and corruption, have not yet been found to have the same degree of sensitivity to the complete inference of PMI. Therefore, a comprehensive assessment of the exact time of death is required by a comprehensive variety of means and methods. There are more methods to infer, but the longer time after death, especially the dead time of decayed corpse, is relatively small, and the error is relatively large, and there is still a lack of accurate and simple methods. Therefore, the assessment of the time of death, especially the long time after death, is still one of the difficult problems in forensic medicine.
Therefore, this experiment applies the theory and technology of biomechanics to the inference of PMI, discusses the relationship between the temporal changes of the biomechanical properties of cadaver tissues and the time of death, and then applies the forensic biomechanics to the inference of the time of death to further expand and extend the application of the forensic biomechanics (Forensic biomechanism). At the same time, this experiment uses Computer digital image analysis technology to analyze and quantify the pathological image of liver cells under HE staining, and apply it to the inference of PMI in forensic pathology, which provides a new trend of pathology in the development of Pathology - the application of quantitative pathology in forensic medicine. In addition, the relationship between PMI and the pathological pictures of the main organs of the corpse was further observed.
Materials and methods
80 healthy male SD rats, 3 to 3.5 months old, weight 250 ~ 300g, were put to death in a constant temperature box and divided into 0,6,12,18,24,30,36,42,48,60,72,96120144168192h time group. The chest skin, abdominal wall muscles, the thoracic aorta, the small intestine and the large intestine were detected by the biomechanical indexes of 5 rats in each group. The limit load was detected. Stress, strain and other soft tissue biomechanical indexes. At the same time, the whole brain, the most lobar liver, the whole heart, the largest left lung leaf, the left kidney were stained with HE section and stereological observation, the morphological changes of autolysis and corruption of the tissue cells were observed, and the pathological image of the liver cells was analyzed and quantified, and the nuclear area, the ratio of nuclear plasma and the nucleus were detected. The relationship between the optical density ratio and the nuclear heteromorphic index was discussed.
Result
1 general and microscopic changes:
General change: after death, the corpse mainly experienced rigor mortem, corpse green, hair loss, abdominal swelling to "giant view", softening collapse process, abdominal viscera gradually liquefaction.
The morphological changes under the microscope: brain, heart, lung, liver, kidney and other parenchyma tissues are changed regularly with PMI, the brain autolysis is relatively fast, the brain autolysis is relatively fast, 48h is difficult to take out, the rate of cardiac autolysis is slower, 96h still can be seen in the myocardium. All tissues and cells have experienced gradually weakened basophilia and gradually increasing eosinophilic activity, and the chromatin chromatin of the nucleus gradually gathered to the most Then break through the nuclear membrane dissolving.
2 biomechanical properties of soft tissue
The maximum limit load of the skin was 11.67N, the minimum load of the small intestine was the smallest, the average of the skin was 1.37N., and the 18h of the small intestine was obviously decreased after the death of the small intestine (Y_ (PMI) =-1.26X_ (ML) +31.03, r=0.985 and Y_ (PMI) =-27.5X_. There was no statistical significance. There was no obvious change trend after 18h in small intestine. The regularity of muscle and large intestine was more similar, 24h was obviously decreased, and the adjacent points had statistical significance (Y_ (PMI) =-5.18X_ (ML) +42.639, r=0.992 and Y_ (PMI) =-7.83X_ (ML)). After that, the change trend was not obvious, which was called "platform period". Among them, muscle 24~9 6h showed a plateau period and then slowed down slowly, but the difference between 96 to 168h was not statistically significant (Y_ (PMI) =-23.812X_ (ML) 173.91, r=0.97), and the 24 ~ 72h of the large intestine was on the platform stage, and then decreased slowly (Y_ (PMI) =-44.05X_ (ML)).
The vascular strain was maximum, average 4.12, but there was no significant statistical significance in the change trend. Other tissues were obviously decreasing in 24h. The trend of muscle and small intestine was not obvious after.24h, and the skin was in platform period from 24 to 72h. After 72h, there was a slow decline trend, and there was no statistical significance from 72 to 96h. After 96 hours, the decline trend was unified. Significance: the large intestine was similar to the skin, and the 24 ~ 72h showed a platform period, and the 72 ~ 192h decreased gradually (Y_ (PMI) =-333X_ (strain) +297.7, r=0.991). The difference of each time point after 120h was statistically significant.
The trend of maximum stress change in each tissue is consistent with the limit load trend, and there is no obvious rule in the blood vessels. After the decrease of other tissues in 24h, the trend is more obvious than that in the small intestine, but it has a downward trend, but it is slower than that in 24h.
Quantitative index of pathological image analysis of 3 liver cells
The change trend of nuclear area of liver was not stable, with the change trend of PMI, the ratio of nuclear plasma ratio decreased gradually. Among them, 0h to 36h (P < 0.05).36h to 60H showed a slow rising trend, but there was no statistical significance (P > 0.05),.60h to 72h decreased significantly (P < 0.05). The nuclear plasma light density increased first and then decreased. Trend, 36h was gradually rising, 36h reached peak value, and the difference between adjacent points had statistical significance (P < 0.05): the difference between 24h and 36h was obvious (P < 0.01).36h to 72h gradually declined, and the time point difference between adjacent points had statistical significance. The abnormal shape index was gradually upward trend within 72 hours (Y_ (PMI) =512.09X_ (ID)).
conclusion
1, there is a significant correlation between PMI and the temporal changes in the morphological changes of the organs. The autolysis and corruption rate of each organ are different. Therefore, there are different characteristics of the organs in each organ in each period of PMI. According to the characteristics of the viscera, the PMI can be estimated. It provides a reference for sex lesion and postmortem autolysis and rotten change.
2 after death, the ultimate load, stress and strain of the soft tissue of the soft tissue, the stress and the small intestine are gradually decreasing with the extension of PMI, and the decrease rate of each tissue at different time after death is different, which makes each organization deduce the "window period" of the PMI and complementarity to a certain extent. It suggests the biomechanical indexes of the soft tissue and the prescription. The method can be used as a simple, objective and quantitative detection method to infer the time of death. There is no obvious rule of blood vessel, which shows the ultimate load and stress of blood vessel, and the strain is not suitable for inference PMI..
3 the quantitative analysis technique of pathological image was applied to PMI to be inferred. It was proved that the ratio of nucleo plasma to nuclear plasma, the ratio of light density of the nucleo plasma, and the heteromorphic index can better reflect the degree of autolysis of liver cells in HE staining. There is no obvious correlation between the degree of autolysis. It is suggested that the relative indexes of the tissue cell's own comparison can avoid the influence of different filmmaking and dyeing effect, and reflect the pathological conditions and grading standards more objectively, and provide a new way of thinking for the quantification of pathology.
【學位授予單位】：汕頭大學
【學位級別】：碩士
【學位授予年份】：2008
【分類號】：D919

【引證文獻】

相關期刊論文 前1條

1 萬勇;李品玉;于文;呂俊耀;于曉軍;;常規(guī)冷凍對大鼠尸體組織形態(tài)學的影響[J];中國法醫(yī)學雜志;2011年01期

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