死后角膜褶皱变化与死后经过时间关系的实验性研究

目的：探讨应用数字图像分析技术研究死后角膜褶皱时序性变化规律并筛选合适量化指标。方法：兔缢死后随机分为睁眼组和闭眼组,每组20只,置于20 ℃暗室内。于死后72 h内每隔1 h,使用数码相机采集兔角膜图像,应用MATLAB软件分割出角膜瞳孔区域图像,并提取反映死后角膜皱褶变化的4项图像纹理特征参数值（CON、COR、ASM、HOM）。比较死后睁、闭眼对各参数值随死后经过时间（postmortem interval,PMI）的变化趋势影响,分析各特征参数（y）与PMI（x）的相关性。结果：不论死后睁眼或闭眼,CON随PMI呈上升趋势,COR呈下降趋势,但睁眼组CON、COR值较闭眼组变化迅速且幅度大;CON、COR值与PMI相关性较好（P<0.05）,回归方程分别为y=0.002 4x2-0.026 8x+0.467 3（R2=0.978,睁眼组）、y=0.000 4x2-0.010 6x+0.304 4（R2=0.904,闭眼组）,y=-0.000 4x2+0.014 2x+3.893 8（R2=0.938,睁眼组）、y=-3E-05x2+0.001 2x+3.980 8（R2=0.852,闭眼组）;ASM、HOM值与PMI关系无统计学意义（P>0.05）。结论：个体死后角膜褶皱发生时序性变化,纹理特征CON、COR与死后经过时间相关性较好。     

兔急性肺损伤死后肝内血管内皮生长因子时序性变化的研究

目的研究大潮气量机械通气致兔急性肺损伤（ALI）12h后处死，死后肝微血管内血管内皮生长因子（VEGF）的动态变化。方法机械通气（VT60mL／kg，R50次／min）致急性肺损伤后12h处死兔，应用免疫组织化学染色（SABC法）和图像分析系统，观测死后不同时间点肝内微血管内皮细胞内vEGF的动态变化。结果对照组死后即刻肝内微血管内皮细胞胞浆vEGF呈弱阳性染色，死后2h阳性染色程度有轻度增加，但以后随PMI的延长VEGF逐渐减弱，死后18h呈阴性；试验组死后肝内微血管的内皮细胞胞浆VEGF呈强阳性表达，但随着PMI延长逐渐减弱，在死亡后0-24h减弱幅度较小，但21-36h阳性染色程度下降较快，直至死后42h随肝内微血管结构崩解而完全消失。结论大潮气量机械通气致急性肺损伤12h处死后，肝微血管内VEGF的变化在一定的时间段内与死亡时间呈现相关关系。     

兔生前骨骼肌钝挫伤死后温度分布场变化的实验性研究

目的:探讨利用红外热成像技术于死后早期检测个体骨骼肌钝挫伤热成像变化,以客观量化分析其随死亡时间变化的规律.方法:制备兔骨骼肌钝挫伤损伤模型后6 h,空气栓塞处死家兔,于损伤即刻、死后即刻、死后6 h、死后24 h、死后3 d、死后6d应用红外热成像仪对家兔伤肢及健肢进行红外热成像及组织病理学检查,提取平均温度(ave...     

尸体眼玻璃体液钾、钡离子浓度与死亡时间的关系

目的寻找一种准确推断死亡时间（postmortem interval,PMI）的方法。方法将20例交通事故尸体按PMI分为13组:死后1h组（2例）、死后2h组（2例）、死后3h组（2例）、死后4h组（2例）、死后5h组（2例）、死后8h组（1例）、死后9h组（1例）、死后10h组（2例）、死后12h组（1例）、死后13h组（1例）、死后14h组（1例）、死后15h组（1例）和死后16h组（2例）。分别检测各组尸体眼玻璃体液中钾离子（K⁺）、钡离子(Ba²⁺)的浓度,并分析其与PMI的相关性。结果死后16h内尸体玻璃体液K⁺、Ba²⁺浓度与PMI相关,其中钾的回归方程为y=4.611+0.141x（R2=0.362,F=10.234）,钡的回归方程为y=-0.001+0.003x-0.000 44x2+0.000 019 2x3（R²=0.498,F=5.301）,其中y为K⁺、Ba²⁺浓度,x为PMI。结论尸体玻璃体液中K⁺、Ba²⁺浓度变化有望作为早期PMI推断的参考指标。     

家兔玻璃体液AKPγ—GT活性变化与PMI的相关性

目的研究死后家兔玻璃体碱性磷酸酶（AKP）和γ一谷氨酰转肽酶（γ一GT）活性与死后经过时间（PMI）的相关性,寻找一种推断PMI的新方法。方法应用酶动力学比色法检测在25~30℃和10~15℃下死后即刻至54h之间玻璃体液AKP和γ一GT活性变化情况。结果从死后即刻至54h之间发现,死后一定时间内,两种酶活性降解均存在平台期,平台期后AKP、γ一GT活性迅速下降,并逐步降解趋于零。经统计学分析,家兔死后两种酶活性与PMI之间有显著的负相关性（P〈0．01）。结论在0h~54h内两种酶活性的降解规律可作为推断PMI的参考指标。     

小白鼠死后脾组织RNA降解程度与死亡时间关系的研究

目的探讨小白鼠死后脾组织GAPDH mRNA和β-actin mRNA降解情况与死亡时间(PMI)的关系。方法 48只NIH小白鼠安乐死处死,分别置于10℃和25℃温控系统内,利用两步法RT-PCR技术和核酸蛋白测定仪定量cDNA方法检测小白鼠脾GAPDH mRNA和β-actin mRNA在死后即刻至72h降解情况。结果在10℃温控系统内的小白鼠死后即刻至72h脾组织均可检测到GAPDH mRNA和β-actin mRNA,且其扩增产物呈规律性下降趋势。25℃温控系统内的小白鼠死后即刻至48h脾组织均可检测到GAPDH mRNA和β-actin mRNA,且其扩增产物呈规律性下降趋势。结论小白鼠死亡后脾GAPDH mRNA和β-actin mRNA降解与PMI负相关,可为PMI推断提供一种新的观测指标。     

死后脾组织mRNA降解程度与死亡时间的关系

目的 探讨小白鼠死后脾组织GAPDH mRNA和β-actin mRNA降解情况与死亡时间(PMI)的关系.方法 24只NIH小白鼠断颈处死,置于25℃温控系统内,利用两步法RT-PCR技术和核酸蛋白测定仪定量cDNA方法检测小白鼠脾GAPDH mRNA和β-actin mRNA在死后即刻至72 h降解情况.结果 在25℃温控系统内的小白鼠死后即刻至48 h脾组织均可检测到GAPDH mRNA和β-actin mRNA,且其扩增产物呈规律性下降趋势.结论 小白鼠死亡后脾组织GAPDH mRNA和β-actin mRNA降解程度与PMI负相关,可为PMI推断提供一种新的观测指标.     

家兔玻璃体液铁、磷含量变化与PMI的相关性研究

目的研究死后家兔玻璃体液铁、磷浓度变化与死亡时间的关系,寻找一种精确推断PMI的方法。方法应用全自动生化分析仪检测样本中铁、磷含量,对所得数据进行统计学处理。结果家兔死后54h内眼玻璃体铁、磷元素与PMI显著相关,其单元回归方程分别为y=14.48-0.244x(x=PMI,y=Fe,r=-0.993)、y=-4.573+0.366x(x=PMI,y=Fe,r=0.965)、y=0.137+0.041x(x=PMI,y=P,r=0.975)。结论在54h内玻璃体液铁、磷含量变化可作为推断PMI的参考指标。     

死后小鼠肾组织细胞核DNA变化规律的研究

目的:研究DNA降解变化与死亡时间的关系,为法医学推断死亡时间提供一种比较准确可靠的新方法。方法:应用单细胞凝胶电泳(SCGE)技术结合荧光显微镜和专业的计算机图像分析技术,测定111只小鼠在死后72h内不同时间点小鼠肾组织细胞核头半径、尾长度、头DNA含量比例、尾DNA含量比例、尾矩、Olive矩、头面积、尾面积8项参数的变化值。结果:在个体死亡72h内,测定的8项参数指标中尾DNA含量比例、彗星尾长、尾矩、Olive矩、尾面积都呈增加趋势,头半径、头DNA含量比例、头面积均呈下降趋势。上述参数均与死亡时间具有高度的相关性。并将每个参数的测量值进行了多项式运算,获得了更能体现DNA降解趋势的二项式回归方程和多元回归方程,均具有高度的统计学意义(P均<0.01)。结论:应用本研究提供的72h内肾组织组织DNA变化与死亡时间之间呈线性关系的各组回归方程,为法医学推断死后经过时间提供了一种新的、客观的、精确的方法和参考依据。     

应用单细胞凝胶电泳检测大鼠死后脾细胞核DNA降解与死亡时间的关系

目的:探讨应用单细胞凝胶电泳技术(SCGE)检测大鼠死后脾细胞核DNA降解与死亡时间的一般规律,为早期死亡时间的推断提供新的方法。方法:建立大鼠死亡模型,在死后27h内,每隔3h取脾组织样本进行单细胞凝胶电泳,用共聚焦显微镜摄取彗星图像,应用彗星图像分析软件(IMI1.0)进行图像分析,并作统计学分析。结果:大鼠死后,脾细胞在电泳图像上出现了明显的彗星形拖尾,其尾长(TL)、尾矩(TM)在一定的时间范围内(0～15h)随死亡时间的延长而逐渐增大,二者均与死亡时间(PMI)呈现一定的相关回归关系。结果:单细胞凝胶电泳技术可应用于早期死亡时间的推断;彗星图像分析软件为SCGE的结果分析提供了便利。     

Image analysis on corneal opacity: A novel method to estimate postmortem interval in rabbits

Corneal opacity is one of the most commonly used parameters for estimating postmortem interval （PMI）. This paper proposes a new method to study the relationship between changes of corneal opacity and PMI by processing and analyzing cornea images. Corneal regions were extracted from images of rabbits＇ eyes and described by color-based and texture-based features, which could represent the changes of cornea at different PMI. A KNN classifier was used to reveal the association of image features and PMI. The result of the classification showed that the new method was reliable and effective.     

大鼠离体肝脏5′-NT和ACP活性与PMI的相关性研究

目的:探讨大鼠死后肝脏内5′-核苷酸酶(5-′Nu-cleotidase,下称5-′NT)和酸性磷酸酶(Acid phosphatase,下称ACP)活性变化与死后经过时间(Postmortem interval,PMI)的相关性。方法:应用分光光度法检测18℃和28℃下大鼠死后肝脏5-′NT和ACP的活性。结果:大鼠死后0~21 h,其肝脏内5-′NT由150 IU/L逐渐降至0,且与时间呈明显的负相关,回归方程为:PMI=23.18-0.774X5-′NT(r=-0.882,P<0.01);而ACP与时间无明显相关性。结论:5′-NT的降解规律可作为推断PMI的参考指标。     

大鼠骨骼肌肌动蛋白在死亡后的形态学变化

目的探讨大鼠骨骼肌肌动蛋白纤维的形态学变化与死亡时间的相关性。方法分别采用激光扫描共聚焦显微镜和透射电镜对大鼠死后不同时间骨骼肌(右后肢的内收大肌)肌动蛋白纤维的形态学变化进行观察。结果大鼠死后,透射电镜观察可见由肌动蛋白构成的细肌丝逐渐崩解、紊乱,直至肌小节和细肌丝结构消失;激光扫描共聚焦显微镜观察可见,自死后24h起,骨骼肌纤维横纹可有小片状或弥漫状抗肌动蛋白抗体缺染灶出现,并且抗肌动蛋白抗体染色面积随着死亡时间的延长而逐渐减少,其变化趋势与死亡时间相关(Y=0.934-0.005X,R2=0.95,P<0.05);大鼠死后168h内,肌动蛋白阳性产物的积分光密度值随死亡时间的延长而逐渐降低,组间差异均具有统计学意义(P<0.05),至死后168h,几乎无抗肌动蛋白抗体染色。结论大鼠骨骼肌肌动蛋白纤维的形态学改变与死亡时间具有相关性。     

大鼠肾HGPRT mRNA降解与死亡时间关系的研究

〗目的:探讨大鼠死后肾次黄嘌呤鸟嘌呤磷酸核糖转移酶(HGPRT)mRNA降解情况与死亡时间(PMI)的关系。方法:40只Wistar大鼠断颈处死,置于20℃温控系统内,利用一步法荧光标记RT-PCR技术检测大鼠肾管家基因HGPRTmRNA在死后即刻至36 h降解情况。结果:在死后即刻至32 h大鼠肾组织均可检测到HGPRTmR-NA,且其扩增产物呈规律性下降趋势。结论:大鼠死亡后肾HGPRTmRNA降解与PMI负相关,可为PMI推断提供一种新的观测指标。     

小白鼠死后肾组织RNA降解程度与死亡时间的关系

目的 探讨小白鼠死后肾组织管家基因甘油醛-3-磷酸脱氢酶(GAPDH)mRNA和内源性对照β-肌动蛋白(β-actin)mRNA降解情况与死亡时间(PMI)的关系.方法 48只美国国立卫生研究院小白鼠断颈处死,分别置于10℃和25℃温控系统内,利用两步法逆转录聚合酶链反应(RT-PCR)技术和核酸蛋白测定仪定量cDNA...     

人体死后不同时间玻璃体液化学成分的变化趋势

目的测定人死后玻璃体液化学成分含量,对多种化学指标进行分析,建立各自的回归方程,使玻璃体液检测能更广泛地应用于法医实践。方法用日本产OL YMPUS AU400自动生化仪对死后时间在0．5-216h的126例尸体玻璃体液中葡萄糖等11种成分的含量进行测定。结果①玻璃体液中葡萄糖、钠、氯随死后时间的延长而逐渐下降;尿素、肌酐、尿酸、钾、钙、镁、无机磷、微量蛋白随死后时间的延长而逐渐升高。葡萄糖、钾离子和无机磷与死亡时间的相关性好（r=-0．824,0．967,0．880）,而尿酸和微量蛋白则不能用于推断死亡时间（r=0．350,0．153）。②死后72h内,死亡时间的逐步回归方程为：Y=-35．15＋6．05X,R^2=0．957,X代表玻璃体液钾离子浓度。Y=-27．83＋5．49X1-1．35X2,R^2=0．960,X1、X2分别代表玻璃体液钾离子、葡萄糖浓度。Y=-16．37＋3．93X1-2．29X2＋5．36X3,R^2=0．966,X1、X2、X3分别代表玻璃体液钾离子、葡萄糖、无机磷浓度。结论①玻璃体液中葡萄糖等11种化学成分的含量随死后时间的延长而改变,其中钾离子在死后72h内与死亡时间最具有线性关系。②用逐步回归法建立多元回归方程推断死亡时间,可以提高对死亡时间估计的准确性。     

Bioluminescent assay of microbial ATP in postmortem tissues for the estimation of postmortem interval

To study the relationship between changes of microbial ATP in four kinds of murine tis-sues and the postmortem interval （PMI）, healthy SD rats were sacrificed and their muscles, livers, spleens and kidneys were sampled at different postmortem intervals. The concentration of microbial ATP was detected using bioluminescent assay and the data was statistically analyzed. The concentra-tion of microbial ATP in muscle increased with PMI time. The peak appeared at the 7th day after death, and at the 10th day, microbial ATP in muscle tissue increased again. In internal organs, the peaks of microbial ATP were observed at the 8th day after death and the level decreased during 8–10 d. The differences in microbial ATP concentration in liver, spleen and kidney were not statistically significant. During day 0 to day 9 after death, the correlation was best between PMI and microbial ATP in muscle. With PMI as the independent variable, the cubic polynomial regression equation was Y=0.02X3–0.166X2–0.666X＋13.412 （R2=0.989, P〈0.01）. In internal organs, the best correlation was found between PMI and microbial ATP during day 0 to day 10. With PMI as the independent variable, the cubic polynomial regression equation was Y=0.016X3–0.127X2–0.809X＋13.324 （R2=0.986, P〈0.01）. There existed high correlations between PMI and microbial ATP concentration in rat tissues. Since only a small amount of tissue was needed for the detection and the sample was not affected by self-decomposition, the method may extend the time range of PMI estimation.     

Correlative Analysis on the Relationship between PMI and DNA Degradation of Cell Nucleus in Human Different Tissues

Summary： To determining the postmortem interval （PMI） through quantitative analysis of the DNA degradation of cell nucleus in human brain and spleen by using image analysis technique （IAT）. The brain and spleen tissues from 32 cadavers with known PMI were collected, subjected to cell smear every 1 h within the first 5-36 h after death, stained by Feulgen-Van＇s staining, Three indices reflecting DNA in brain cells （astrocytes） and splenic lymphocytes, including integral optical density （IOD）, average optical density （AOD）, average gray （AG） were measured by employing the mage analysis instrument. The results showed that IOD and AOD declined and AG increased with the prolongation of dead time within 5 36 h. A correlation between the PMI and gray parameters （IOD,AOD and AG） was identified and the corresponding regression equation was obtained. The parameters （IOD, AOD and AG） were proved to be effective quantitative indicators for accurate estimation of PMI within 5-36 h after death.     

Spectrophotometric Determination of Trimethylamine-nitrogen in Cadaver Tissues for the Estimation of Late Postmortem Interval：A Pilot Study

To study the relationship between the late postmortem interval (PMI) and trimethyl-amine-nitrogen (TMA-N) in postmortem tissues of cadaver, TMA-N in muscles, livers and kidneys of rats was measured at different postmortem intervals (PMI) by using a modified spectrophotometric method. The results indicated that the detection sensitivity of TMA-N was 1 mg/L, and there was a good linear correlation between the value of absorbance (A value) and TMA-N at the concentration of 1-10 mg/L (R2=0.9991). Although TMA variation in muscles was different from that in inner organs during the time since death, TMA-N changes in cadaver tissues was positively correlated with PMI. During 2 to 7d since death, the best correlation between PMI and TMA-N concentration was found in muscles. With PMI as an independent variable, the cubic polynomial regression equation was y=-0.457x3 6.519x2-24.574x 27.207 (R2=0.969). During 3 to 8 days since death, PMI was best correlated with TMA-N concentration in inner organs. With PMI as the independent variable, the cubic polynomial regression equation was y=0.509x3-9.153x2 55.727x-95.819 (R2=0.953). It was concluded that TMA-N in tissues could be used as a new estimator for late PMI. The method used in this study offered advantages such as accuracy, sensitivity, little samples required and wide PMI estimation.