家兔死后眼玻璃体液镁，铁含量与PMI关系的研究

目的寻找一种精确推定PMI的方法。方法应用电感耦合等离子体质谱(ICP-MS),检测家兔死后96h内眼玻璃体液镁、铁元素含量,探讨其与PMI的相关性。结果家兔死后0～48h眼玻璃体液镁元素含量与PMI显著相关,6～48h铁元素含量与PMI显著相关,其二项式回归方程分别为y=0.0738x2+0.6997x+11.45(R2=0.9119)、y=0.0411x2-0.3148x+1.4113(R2=0.9594)。结论家兔死后眼玻璃体液Mg、Fe含量变化可作为推定48h内PMI的参考指标之一。     

Spectroscopic determination of skin viability. A predictor of postmortem interval

We have demonstrated that skin viability decreases at a measurable rate following death in an animal model. The decreased skin viability was measured by fluorescein diacetate and ethidium bromide using fluorescence emission spectroscopy. There is significant decrease of the fluorescence intensity of the fluorescein diacetate assay between the 1-4 h, the 6-24 h, and the >40 h time points postmortem. For times between 6-24 h and >40 h postmortem the ethidium bromide assay showed consistent and significant increases in signal. The fluorescence measurements in this study showed that under the experimental conditions the time of death could be determined for <4, 6-24, and >40 hapotmotrem. The application of these assays in the field will require further study of the environmental factors.     

Evaluation of hypostasis using a colorimeter measuring system and its application to assessment of the post-mortem interval (time of death)

Hypostasis was measured in 93 cadavers using a tristimulus colorimeter in order to investigate its relationship with the time of death. The intensity (lightness) of the hypostasis in each case was measured over a period of 4 h and the rate of change in lightness derived. When examined against the time of death, it was found that there was a good correlation between the two. Namely, that the rate of change of lightness (and it can be inferred that this represents displaceability) decreases as the post-mortem period increases. The shift in hypostasis was particularly marked in the first 12 h and decreased thereafter. However, hypostasis could be useful for time of death estimation for up to 48 h. After this time, the degree of change was small or non-existent and by 72 h hypostasis had become fixed in the majority of cases, within our measuring period of 4 h.     

家兔死后不同时间角膜基质胶原纤维的超微结构观察

目的探讨角膜基质胶原纤维直径变化与死亡时间的关系。方法28只家兔空气栓塞致死后,按死后不同时间取角膜,常规方法制作超薄切片,应用透射电镜观察角膜基质0.5μm×0.5μm区域内的胶原纤维,并用图像分析系统测量反映胶原纤维直径变化的横切面面积(Y1)、周长(Y2)、平均直径(Y3)、等效直径(Y4)4个参数,所得数据用EXCEL2000和SPSS10.0软件进行统计分析。结果在死后0～72h内,角膜胶原纤维横断面的面积从1131±53nm增加到1628±26nm,周长从132.8±23nm增加到167.5nm,等效直径从38nm增加到45nm,平均直径从37.71±6nm增加到44.89±5nm。结论死后72h内,角膜基质胶原纤维直径随死后时间的延长逐渐增大,4个参数有望作为判断死后时间的新指标。     

Postmortem disposition of morphine in rats

The antemortem and postmortem distribution of morphine was studied in rats for the purpose of establishing whether drug distribution is altered after death. Samples were examined for free and total morphine concentration, pH and water content at 0-96 h after death. Morphine was administered antemortem at various intervals. All groups of rats studied showed a significant (P less than 0.05) increase in postmortem cardiac blood morphine concentrations. These changes, which are detectable within 5 min after death are likely to be related to an observed, rapid decrease in cardiac blood pH from 7.34 +/- 0.02 to 6.74 +/- 0.05. Significant increases in free morphine levels were, also, observed 24 and 96 h after death in liver, heart and forebrain while urine morphine levels decreased. The liver showed the greatest increase (20-fold) in free morphine levels 96 h after death, while hindbrain levels did not significantly change. Bacterial hydrolysis of morphine glucuronides accounted only in part for the observed increase in free morphine concentration. Postmortem fluid movement and pH-dependent drug partitioning was detected. It would appear that several mechanisms are responsible for postmortem drug distribution. Understanding the mechanisms and patterns responsible may eventually lead to better choices of postmortem tissue which may better represent antemortem drug levels.     

大鼠死后视网膜细胞mRNA降解与死亡时间的关系研究

目的检测死后大鼠视网膜细胞mRNA的降解和死亡时间(PM I)的关系,为死亡时间推断提供新方法。方法应用复合荧光RT-PCR技术,检测死后不同时间(2、4、6、8、10、12、14、16、18、20、22、24、26、28h)大鼠视网膜细胞β-actin、Pgk1和Rp l 4 mRNA水平,以立即处死大鼠作为对照。方差检验比较组间差异,并对所得数据进行回归分析。结果死后28h内,大鼠视网膜细胞β-actin、Pgk1、Rp l 4 mRNA水平均随死亡时间的延长而下降。3个管家基因mRNA的降解与死亡时间的线性拟合回归方程分别为:Yβ-actin=-4436.205Xβ-actin+127581.7(r2=0.976),YPgk1=-1993.884XPgk1+57651.54(r2=0.973),YRp l 4=-1189.791XRp l 4+34533.46(r2=0.955)。结论大鼠死后视网膜细胞mRNA的含量随着死亡时间的延长而逐渐降解,与死亡时间具有相关性。     

缢死大鼠肝肾细胞内HIF-1α免疫组化染色观察

目的探讨缺氧诱导因子1α(HIF-1α)在窒息死亡鉴定中的意义。方法制作大鼠缢死后0、2、6、24h的窒息死模型,以相应时间段断颈处死大鼠为对照,用免疫组织化学ABC法结合图像分析观测肝和肾组织中的HIF-1α表达情况,并对其结果进行统计分析。结果除0h段外,HIF-1α免疫组化阳性染色可见于窒息组和对照组的各时段大鼠,主要位于肝细胞、肾近曲小管和远曲小管上皮细胞。死后6h内的肝组织HIF-1α免疫组化染色显示窒息组与对照组差别明显(P<0.05),24h后则无明显差别(P>0.05)。肾脏窒息组与对照组差别明显(P<0.05)。结论观测HIF-1α在死后6h内肝脏或24h内肾脏中的表达状态,对机械性窒息的鉴定有一定的法医学意义。     

不同死因大鼠死后不同时间红细胞溶血速度比较

目的观察不同死亡原因大鼠尸体血液中红细胞溶血速度的变化规律,为死亡原因的法医学推断提供新思路。方法 40只SD大鼠随机分为4组,分别以断髓、置于99%CO的空间、高坠、勒颈方式处死后,取各组大鼠右心室血液,于死后即刻（0h）、8h、16h、24h、32h、40h、48h、56h、64h、72h,采用显微镜数码图像法进行全血红细胞计数（CBC）,并对组内和组间数据进行统计学比较分析。结果 4组血液红细胞数量在死后即刻至72h期间,均随时间的延长因溶血而减少。其中0~16h,各组溶血速度无明显差异（P〉0.05）;16~48h,速度加快,溶血速度以CO中毒组（88.50±25.99）%最快,其次为高坠（69.33±29.52）%和断髓组（48.78±3.17）%,机械性窒息组（41.90±9.61）%最慢,组间比较具有显著性差异（P〈0.05）;56h后,溶血速度再次减慢,至72h机械性窒息组仍有少量红细胞存在。结论 4组不同死因大鼠死后不同时间红细胞计数均减少,各组间差异具有统计学意义,其变化特征可为死亡原因的推断提供新的思路。     

Factors influencing the precision of estimating the postmortem interval using the triple-exponential formulae (TEF). Part II. A study of the effect of body temperature at the moment of death on the postmortem brain, liver and rectal cooling in 117 forensic cases

The temperatures of three body sites, namely, the brain, liver and the rectum as well as the temperature of the environment were continuously monitored, every 5-10 min, in 117 forensic cases commencing soon after death and in most cases, within 45 min postmortem. The body temperature at the moment of death was empirically determined by a computer-based extrapolation method. Thus, temperature data for the first 3h of each body site were fitted to single-exponential equations and the fitted curve was extrapolated backwards to obtain the intercept on the Y-axis (the temperature axis). The effect of body temperature at the moment of death on postmortem cooling rate is examined and factors influencing body temperature at death are discussed. Forensic fatalities associated with hyper and hypothermia are reviewed briefly.     

小鼠骨骼肌细胞核DNA降解与死亡时间的关系

目的　监测小鼠死后骨骼肌核内DNA降解的情况 ,探讨死后细胞核DNA降解的一般规律。方法　建立小鼠死亡模型 ,在死后 72h内 ,以 12h的间隔取骨骼肌样本进行单细胞凝胶电泳 ,在荧光显微镜下测量彗星图像 ,并作统计学分析。结果　机体死后 ,骨骼肌细胞在电泳图像上出现了明显的彗星形拖尾 ,L/W比值随死亡时间而逐渐增大 ,二者呈一定的线性关系。结论　单细胞凝胶电泳技术可以应用于早期死亡时间推断。     

大鼠百草枯中毒后体内的分布研究

目的建立生物检材中百草枯的超高效液相色谱-质谱联用检测方法,研究百草枯灌胃染毒致死的大鼠动物模型。方法大鼠以1/2 LD_(50)剂量灌胃染毒,分别于染毒后0.5h、2h、4h、8h、12h、24h、48h、72h处死解剖,采集心、肝、脾、肺、肾、脑、肌肉、膀胱和胃组织,UPLC-MS/MS法定量检测各组织中百草枯。结果试验中大鼠灌胃后,4h以内胃是主要分布器官,胃中含量最多,其他器官中含量相对较低。4h内除胃以外的脏器含量变化不大,4h后胃内百草枯含量有所下降,除胃以外的脏器含量均升高。各组织与脑组织比较具有显著性差异(P0.05)。结论百草枯在大鼠体内死后分布不均匀并且各组织含量随着时间变化有所改变。百草枯UPLC-MS/MS方法、口服染毒致死的动物模型、各组织分布规律可为甲百草枯中毒死亡案件提供检测依据。     

氯氮平在家兔体内死后再分布规律研究

目的阐明死后48h内家兔体内氯氮平再分布规律,为相关法医鉴定工作提供借鉴。方法取家兔15只,随机分为5组,以氯氮平灌胃,分别于死后0、6、12、24、48h取心血、外周静脉血、尿液、肝组织检测氯氮平浓度。结果家兔死亡后心血、外周静脉血、肝脏氯氮平浓度不断升高,尿液氯氮平浓度不断降低;死后早期浓度变化率大于晚期浓度变化率。死后48h心血、外周静脉血、肝脏、尿液氯氮平浓度分别为死后0h各检材氯氮平浓度的418%、193%、154%和29%。结论死亡一段时间后,提取生物检材,检测出的氯氮平浓度并不能准确反映刚死时的实际浓度。     

The temporal fate of drugs in decomposing porcine tissue

Drug levels in decomposed individuals are difficult to interpret. Concentrations of 16 drugs were monitored in tissues (blood, brain, liver, kidney, muscle, and soil) from decomposing pigs for 1 week. Pigs were divided into groups (n = 5) with each group receiving four drugs. Drug cocktails were prepared from pharmaceutical formulations. Intracardiac pentobarbital sacrifice was 4 h after dosing, with tissue collection at 4, 24, 48, 96, and 168 h postdosing. Samples were frozen until assay. Detection and quantitation of drugs were through solid phase extraction followed by gas chromatograph/mass spectrometer analysis. Brain and kidneys were not available after 48 h; liver and muscle persisted for 1 week. Concentration of drugs increased during decomposition. During 1 week of decomposition, muscle showed average levels increasing but concentrations in liver were increased many fold, compared to muscle. Attempting to interpret drug levels in decomposed bodies may lead to incorrect conclusions about cause and manner of death.     

大鼠骨骼肌挫伤后Fzd2表达与损伤时间的关系

目的检测大鼠骨骼肌挫伤后卷曲受体蛋白2(frizzled-2,Fzd2)mRNA及其蛋白表达量与损伤时间的关系,探讨其是否可以作为损伤时间推断的指标。方法利用RT-qPCR和Western印迹法检测正常对照组及损伤后4~48 h每4 h大鼠骨骼肌中Fzd2 mRNA和蛋白水平的表达量。结果 Fzd2 mRNA在损伤后24 h、36 h、40 h相对表达量增高,24 h组表达量达正常对照组的两倍(P0.05);而Fzd2蛋白在损伤后相对表达量变化不明显(P0.05)。结论大鼠骨骼肌损伤后Fzd2 mRNA在一定时间内的表达变化情况可以作为多指标联合推断损伤时间的依据。     

小鼠皮肤切创IL-10和IL-4的表达及其与损伤时间关系

目的　探讨IL 10、IL 4在小鼠皮肤切创愈合过程中的表达变化规律及其与损伤时间的关系。方法　应用免疫组织化学及图像分析技术 ,观察实验小鼠不同时程的生前伤 ( 0 5～ 168h)及死后伤 ( 1～ 6h)皮肤创伤局部IL 10、IL 4的表达情况。结果　生前伤 ,IL 10在伤后 1～ 3h阳性反应逐渐增强 ,3h达峰值 ,2 4h降至较低水平 ,伤后 48h再次升高 ,72h又达新峰值 ,其阳性表达部位主要在表皮细胞及单核 /巨噬细胞 ;IL 4于伤后 2 4h出现明显阳性反应 ,96h表达水平达峰值 ,168h仍维持在较高水平 ,其阳性细胞主要为创伤局部的成纤维细胞。死后伤 ,IL 10仅于死后 1～ 3h呈阳性染色 ,IL 4未见阳性染色。结论　IL 10、IL 4在小鼠皮肤切创愈合过程中的表达呈现一定的时序性变化。     

Supplementary pathway for vitality of wounds and wound age estimation in bruises using the electric impedance spectroscopy technique

Determination of wound vitality and estimation of wound age are central issues in daily forensic practice. The objective of this study was to develop a new and rapid method for determining wound vitality and estimating wound age in bruises using electric impedance spectroscopy. Forty Sprague-Dawley rats (140-170 g) were divided into five groups: group 1 (n=8): controls, group 2 (n=8): postmortem bruises, group 3 (n=8): bruises 1 h before death, group 4 (n=8): bruises 3 h before death, group 5 (n=8): bruises 6 h before death. Measurements of the right gluteus maximus muscle were taken at 6, 24, and 48 h after the rats were sacrificed by cervical dislocation. The results from this study indicate that electric impedance spectroscopy is clearly sensitive enough to differentiate between vital and postmortem wound infliction and to determine the survival time after the infliction of an injury.     

蛋白质降解与死亡时间推断的初步研究

目的观察大鼠肝脏肌动蛋白、微管蛋白在死后不同时间的降解情况,为死亡时间的推断寻找客观依据。方法大鼠麻醉致死后置于21℃温度控制系统模拟死后18d的改变,在不同时间点剪取肝脏组织抽提蛋白质,利用westernblot技术检测肌动蛋白、微管蛋白的降解变化并对产物进行半定量分析。结果大鼠肝脏肌动蛋白在死后8d尚可检测,死亡10d后检测不到;在死后2d,α微管蛋白已检测不到,但可检测到β微管蛋白,死亡4d后,β微管蛋白也检测不到。结论肌动蛋白、微管蛋白的死后降解存在差异,其在肝脏组织保存时间的不同可作为死亡时间推断的参数。     

Comparison of morphological changes in white blood cells after death and in vitro storage of blood for the estimation of postmortem interval.

Estimation of the time of death is one of the most important problems for forensic medicine and law. Physical and chemical postmortem changes are evaluated together while estimating the time of death.In this study, in vitro storage and postmortem changes of white blood cells were aimed to be compared within the given postmortem interval, and a follow-up study was carried out. Blood smears which were obtained from 10 non-refrigerated cadavers (experimental group) and from 40 hospital patients (control group) have been evaluated to observe and compare changes during the in vitro storage and postmortem degenerative morphological changes that white blood cells undergo throughout the given postmortem intervals. The samples were examined by using a light microscope, and blood cells were differentiated by staining blood films with May-Grunwald stain, followed by Giemsa stain. Identifiable degenerated eosinophils and monocytes were first examined at 6h of death and the in vitro storage, and they were unidentifiable beyond 72 h of storage. Identifiable degeneration of neutrophils were first examined at 6h of death and storage while unidentifiable beyond 96 h of storage. Identifiable degeneration of lymphocytes were first examined at 24h of death, and they were still identifiable beyond 120 h.Cellular changes of leukocytes can be useful in the 6-120 h for estimating the time of in vitro storage, and the findings match during the first 21 h for both experimental and control groups. Finally, this follow-up study and the comparison will also be carried out for a longer postmortem interval, and other specific hypothesis that relate cellular changes in tissues other than blood with time since death are various points that needs to be studied.     

The Effect of Decalcifying Solutions on Hemosiderin Staining

Abstract: To determine whether routine decalcification may reduce the amount of stainable iron that is visible on tissue sections, samples of liver and lung tissue with excessive iron stores were placed in three standard decalcifying solutions (i) formic acid [33%], formaldehyde [4%], and NaCl [0.85%]; (ii) formic acid [30%], formaldehyde [4%], and water; and (iii) nitric acid [5%] for 24, 48, 72, and 96 h. After exposure to the decalcifying solutions, the tissues were stained with Perls stain. The slides were examined blind and the intensity of iron staining was scored semiquantitatively from 0 to 3+. The trend in all samples over the course of the experiment (96 h) was for reduction in the intensity of hemosiderin staining. As the amount of stainable hemosiderin in tissues may be significantly altered by decalcification, the absence of hemosiderin in tissues adjacent to a fracture site does not necessarily indicate that the injury was acute.     

豚鼠过敏性休克肺组织中类胰蛋白酶和胃促胰酶的表达

目的观察豚鼠过敏性休克死亡肺组织中类胰蛋白酶和胃促胰酶的表达情况,试图为过敏性休克死亡提供客观的诊断依据。方法健康豚鼠24只,随机均分为实验组和对照组,每组再分死亡即时组、冷藏48h组和冷冻7d组,每组4只。实验组将0.5mL人混合血清用生理盐水1∶10稀释,注射于豚鼠后掌皮内,致敏后3周以人混合血清1mL注入心腔诱发过敏性休克致死;对照组采用生理盐水代替混合血清。提取豚鼠心血及肺组织,应用免疫组化染色和图像分析技术观察类胰蛋白酶和胃促胰酶的表达情况。结果对照组豚鼠肺组织中类胰蛋白酶和胃促胰酶阳性细胞数量较少,分布在小血管和小气管周围。实验组肺组织中类胰蛋白酶和胃促胰酶阳性细胞明显增多,多数细胞形态不规则,阳性染色颗粒脱出肥大细胞并弥散到组织间隙。冷藏48h和冷冻7d的条件下对这两种酶的表达无明显影响。结论过敏性休克致死豚鼠肺组织中类胰蛋白酶和胃促胰酶的表达明显增强,在冷藏48h和冷冻7d内的条件下,可作为过敏性休克死亡的一项诊断依据。