Linearization of the relationship between postmortem plasma chloride concentration and postmortem interval in rats

A potentiometric titration procedure was employed for measurement of plasma chloride concentrations during the 0-96 h postmortem period in rats. The data revealed antemortem absolute values and postmortem rate of decrease in plasma chloride concentration (PCl) which were almost identical to those in dogs and in man. Expression of the data in the form of a double logarithmic plot of PCl versus postmortem interval (PMI) yielded a linear relationship of high correlation (r = -0.97; P less than 0.001). Attention is drawn to the possibility of utilizing postmortem rate of change in plasma chloride concentration as a means of estimating time elapsed since death.     

Shadow positioning technique: a method for postmortem identification

Radiology is increasingly being used as a means of postmortem identification. We have devised a shadow positioning technique by which a postmortem radiograph of a skeletal part can exactly duplicate an antemortem radiograph, thus, faciliating identification by comparison of the antemortem and postmortem radiographs. The antemortem radiograph can be of any skeletal part and taken in any position.     

Distinguishing antemortem from postmortem injuries by LTB4 quantification

Leukotriene B₄ (LTB₄) in skin samples from seven forensic cases was detected by HPLC to distinguish their antemortem or postmortem origin. In total, there were thirteen antemortem and seven postmortem specimens. The results showed that LTB₄ was found in all antemortem wound specimens which were either fresh, or refrigerated or fixed in formalin for less than 10 days. In contrast, LTB₄ could not be detected in postmortem wound specimens. These results suggested that detecting the content of LTB₄ is a useful method for distinguishing antemortem from postmortem injuries.     

The extent of postmortem drug redistribution in a rat model.

The aim of this study was to investigate the postmortem redistribution of several drugs in a rat model and to examine if any of the pharmacological properties was related to the extent of this phenomenon. One of the following drugs: phenobarbital (phenobarbitone), acetaminophen (paracetamol), carbamazepine, codeine, verapamil, amphetamine, mianserin, trimeprazine (alimemazine) or chloroquine was administered together with nortriptyline orally to rats 90 min prior to sacrifice. Heart blood was sampled immediately before sacrifice and after 2 h postmortem, as it has previously been shown that this is sufficient time for postmortem concentration changes to occur in heart blood. Blood was also sampled from the clamped abdominal inferior vena cava (representing peripheral blood) and tissue samples were taken from lungs, myocardium, liver, kidney, thigh muscle, forebrain, and vitreous humor together with a specimen from the minced carcass. Drugs were analyzed by high performance liquid or gas chromatography. For phenobarbital, acetaminophen and carbamazepine the postmortem to antemortem blood drug concentration ratios were close to 1.0 and tissue concentrations were low. The postmortem to antemortem heart blood drug concentration ratio for chloroquine (6.9 +/- 1.5) was higher than for nortriptyline (3.5 +/- 0.3), and the remaining drugs (codeine, verapamil, amphetamine, mianserin, and trimeprazine) showed ratios of the same magnitude as nortriptyline. The postmortem to antemortem blood drug concentration ratios for both heart blood and blood from the vena cava and also the lung to antemortem blood drug concentration ratio were closely related to the apparent volume of distribution for the drugs studied (p < 0.001). Accordingly, an apparent volume of distribution of more than 3-4 L/kg is a good predictor that a drug is liable to undergo postmortem redistribution with significant increments in blood levels. The postmortem drug concentration in blood from vena cava was closely related to the antemortem blood level, confirming that among the postmortem samples, the peripheral blood sample was the most representative for the antemortem blood concentration.     

Postmortem redistribution of fentanyl in the rabbit blood

Postmortem redistribution of fentanyl in the rabbit was investigated after application of the 50-μg/h Durogesic pain patch. Patches were applied for 48 hours. Two cycles of patch administration were used before characterization of the postmortem redistribution. Fentanyl showed marked redistribution into the femoral and pulmonary veins of the rabbit through 48 hours after the animals were humanely killed and the pain patches removed. The plasma concentration of 2.34 ng/mL in the femoral blood before killing the animals increased 5.6-fold by 48 hours after patch removal to 13.2 ng/mL. This postmortem concentration is approximately 3-fold the C(max) determined during antemortem pharmacokinetic analysis, 4 ng/mL, which was achieved 24 hours after the application of the second 50-μg/h Durogesic pain patch. After blood sampling for 48 hours after animal termination with patch removal compared with sampling for 48 hours from animals not terminated and with patch removal, the exposure ratios in the terminated animals were approximately 30-fold, indicating that between the postmortem redistribution of fentanyl and the cessation of hepatic clearance of fentanyl in the rabbit, the postmortem redistribution of fentanyl leads to an elevated measures of postmortem blood concentrations relative to antemortem blood concentrations.     

对纤维蛋白诊断生前伤的评价——45例枪弹创组织的MSB染色和扫描电镜对比观察

生活反应是诊断生前伤的主要根据.近二十年来,法医病理学在研究生前伤和死后伤的诊断中,采用了多种新兴技术,如扫描电镜技术、酶组织化学技术、酶标技术、电泳技术等,促使生前伤的诊断水平有明显提高.伤后存活1小时死亡者,大部分皆可获得明确诊断;立即死亡或在濒死期形成的损伤,由于生活反应甚微,或受腐败等     

GrinLine Identification Using Digital Imaging and Adobe Photoshop*

Abstract: The purpose of this study was to outline a method by which an antemortem photograph of a victim can be critically compared with a postmortem photograph in an effort to facilitate the identification process. Ten subjects, between 27 and 55 years old provided historical pictures of themselves exhibiting a broad smile showing anterior teeth to some extent (a grin). These photos were termed “antemortem” for the purpose of the study. A digital camera was used to take a current photo of each subject’s grin. These photos represented the “postmortem” images. A single subject’s “postmortem” photo set was randomly selected to be the “unknown victim.” These combined data of the unknown and the 10 antemortem subjects were digitally stored and, using Adobe Photoshop software, the images were sized and oriented for comparative analysis. The goal was to devise a technique that could facilitate the accurate determination of which “antemortem” subject was the “unknown.” The generation of antemortem digital overlays of the teeth visible in a grin and the comparison of those overlays to the images of the postmortem dentition is the foundation of the technique. The comparisons made using the GrinLine Identification Technique may assist medical examiners and coroners in making identifications or exclusions.     

Study of elastic fiber changes of human skin in distinction between antemortem and postmortem wounds

Elastic fiber changes of volunteers' antemortem and postmortem skin wounds of various time were observed in order to find possible differences between them. These sections of the wounds were stained by Hart's modification of Weigert's elastic tissue stain.. However, this study showed that there were no differences in the nature and distribution of the elastic fibers in the dermis of volunteers' antemortem and postmortem human skin wounds. Therefore, this suggests that the appearances of the elastic fibers in the dermis should not be as a means of differentiating antemortem skin wounds from postmortem wounds in forensic identification.     

枪弹创纤维蛋白形成能力的免疫组化研究

采用免疫组化PAP染色法，对57例人体枪弹创标本的纤维蛋白形成能力进行检测。结果发现，所有生前枪弹创均有纤维蛋白形成祖创缘邻近皮肤组织内毛细血管内皮细胞以及血管内充盈的红细胞膜上亦呈棕色阳性染色；死后30min内形成的枪弹创均有纤维蛋白形成；死后37min后形成的枪弹创无纤维蛋白形成，说明死后30min，纤维蛋白形成能力仍存在。作者认为，仅根据损伤局部有纤维蛋白形成即判断为生前伤是不恰当的，尚应结合损伤部位、损伤程度、损伤类型以及其它生活反应综合评定，不宜单凭纤维蛋白判断。     

电击死兔骨骼肌及心肌HSP70 mRNA和c-fos mRNA表达

目的 研究电击死兔骨骼肌与心肌HSP70 mRNA和c-fos mRNA-表达变化。探究生前电击与死后电击的鉴别方法。方法 15只新西兰兔,随机分电击死组、死后电击组和对照组,每组5只,用荧光RT-PCR技术检测骨骼肌与心肌热休克蛋白70（HSP70） mRNA与c-fos mRNA表达水平,对所得结果进行统计学分析。结果 生前电击兔骨骼肌及心肌HSP70 mRNA与c-fos mRNA表达高于死后即刻电击者（P〈0．05）。结论 检测骨骼肌及心肌HSP70 mRNA与c-fos mRNA表达变化有助于于生前电击与死后电击的鉴别。     

扫描电子显微镜下生前和死后枪弹创的对比观察

本文用扫描电镜,对11例生前枪弹创和12例死后不同时间形成的枪弹创作对比观察。结果发现,生前枪弹创有大量红细胞和血小板凝块,纤维蛋白网形成,死后10min内的枪弹创亦有少许散在红细胞和纤维蛋白形成,很少见纤维蛋白网。死后25min的标本仍可见稀疏的红细胞,但无纤维蛋白形成。作者认为在扫描电镜下诊断生前枪弹创,需全面观察,综合分析。     

Timely antemortem and postmortem concentrations in a fatal carbamazepine overdose.

There are no published reports that include both timely antemortem and postmortem carbamazepine concentrations after massive overdose. We report a fatal overdose of carbamazepine with both timely antemortem and postmortem carbamazepine concentrations. Carbamazepine concentrations were 47.7 mcg/mL 2 h antemortem and 53 mcg/mL at 9 h postmortem. The slight rise in drug concentration may reflect continued absorption of the drug in the last 2 h before death. Postmortem carbamazepine concentrations drawn from a peripheral vessel in this patient appeared to reflect drug concentrations at the time of death.     

Frozen cadaver. Antemortem versus postmortem.

Three categories of skin from Hanford miniature swine were examined microscopically: normal, unfrozen skin; skin exposed to -75 degrees C air for 5 min, 6 h postinjury; and skin frozen postmortem. Frostbitten skin (antemortem freezing) was characterized grossly by a purple discoloration and microscopically by dilated, blood-filled, superficial capillaries. Other changes in the frostbitten skin were vacuolated epithelial cells and dermal edema. Unfrozen skin (controls) and skin frozen postmortem were more difficult to differentiate. However, the epidermis of the latter usually was compressed and more basophilic. We concluded that skin frozen antemortem could be separated from skin frozen postmortem by its intense hyperemia, characterized grossly as a purple discoloration and microscopically by engorged capillaries.     

Skeletal identification using the frontal sinus region: a retrospective study of 39 cases

The importance of identification using the frontal sinus has been previously demonstrated in case reports. In this study, 39 cases of identification using frontal sinus comparison from the Ontario Chief Coroner's Office were reviewed and differences between antemortem and postmortem radiographs examined. All cases involved decedents older than twenty years. Three cases were rejected due to poor antemortem and postmortem film quality. One subject had no frontal sinus. Thirty-five cases provided conclusive postmortem to antemortem pattern matches. Sixteen cases also yielded metric (quantitative) matches. Duration between antemortem and postmortem radiographic examinations, age, gender, and cause of death did not affect the ability to obtain a match. This is the largest study undertaken on actual cases and demonstrates the validity of frontal sinus pattern matching for forensic identification.     

家兔死后体表锐器伤出血现象的研究

目的对家兔死后体表锐器损伤出血现象进行研究,以期能够贴近实际办案需要,找到一个更为实用的鉴别生前锐器伤和死后锐器伤的方法。方法家兔脱毛,制作锐器损伤模型,采用大体观察结合HE染色镜下组织病理学观察。结果死后锐器损伤出血量均较少,随着时间延长出血量减少,出血速度慢。死后30min的锐器损伤在形成过程与生前损伤有所区别,但在死后12h肉眼观察结果与生前损伤难以区别。死后1h以上的锐器损伤与生前损伤不同之处在于创缘不会被血染。结论位于尸体低下位置的死后30min内的锐器创与生前锐器创的区别是出血量相对较少。死后60min-90min的锐器伤出血量少,创缘皮肤不被血染,肌肉的出血较局限,与生前损伤相鉴别较容易。     

Postmortem skeletal lesions

Postmortem bone alterations are very frequent and can raise the issue of their nature (antemortem, perimortem or postmortem defects). The aim of this work is to study various aspects of defects which were not assessed as perimortem trauma, from a series of 50 defects examined, resulting from 24 forensic cases. This study emphasizes the variability of size, shape and number of postmortem defects. Usually the diagnosis of antemortem defects is helped by a careful examination of some characteristics as the edges of the defects, the areas of discoloration of the edges and of the whole bone. Elsewhere it appears very difficult to know the true nature (antemortem, postmortem, or perimortem alterations) of the bone.     

Crack Propagation in Teeth: A Comparison of Perimortem and Postmortem Behavior of Dental Materials and Cracks*

Abstract: This study presents a new method for understanding postmortem heat-induced crack propagation patterns in teeth. The results demonstrate that patterns of postmortem heat-induced crack propagation differ from perimortem and antemortem trauma-induced crack propagation patterns. Dental material of the postmortem tooth undergoes dehydration leading to a shrinking and more brittle dentin material and a weaker dentin-enamel junction. Dentin intertubule tensile stresses are amplified by the presence of the pulp cavity, and initiates crack propagation from the internal dentin, through the dentin-enamel junction and lastly the enamel. In contrast, in vivo perimortem and antemortem trauma-induced crack propagation initiates cracking from the external surface of the enamel toward the dentin-enamel junction where the majority of the energy of the crack is dissipated, eliminating the crack’s progress into the dentin. These unique patterns of crack propagation can be used to differentiate postmortem taphonomy-induced damage from antemortem and perimortem trauma in teeth.     

Postmortem methemoglobin concentrations and their significance

Small concentrations of methemoglobin are present in the blood of normal individuals. Increased concentrations of methemoglobin can be formed by the action of certain chemicals or drugs, or in individuals with specific genetic defects. There is little information available concerning the validity of postmortem methemoglobin concentration as an indicator of antemortem methemoglobinemia. We measured blood concentrations of methemoglobin in 49 autopsy specimens. We conclude that postmortem methemoglobin concentrations are not valid indicators of antemortem methemoglobinemia.     

Postmortem metabolic indices of antemortem adrenergic stimulation

Tissue lactate concentration has been reported to be a useful postmortem indicator of antemortem awareness of mortal danger. The purpose of this study was to determine further whether selected tissue metabolites could be used as postmortem markers of antemortem adrenergic stress. Sprague-Dawley albino rats were anesthetized with pentobarbital and then injected with 2.0 mg kg-1 i.p. epinephrine hydrochloride to induce experimentally a severe sympathetic response that may be associated with the awareness of mortal danger; 20 min after the injection of epinephrine, when the metabolic response was at its peak, the animals were killed by exsanguination. Samples of the following tissues were removed immediately prior to death (0 h) and 48 h postmortem: soleus, plantaris, kidney medulla, kidney cortex, liver, and heart. These samples were analyzed for glycogen, lactate, ATP, creatine phosphate, pH, and total protein concentration. Significant differences in lactate concentration were observed in all tissues except soleus at 0 h in the epinephrine-injected animals. Specific tissues also had significant reductions in glycogen, ATP, and creatine phosphate concentrations at 0 h. At 48 h postmortem, however, only the liver and soleus lactate concentrations were significantly different from the 48-h control samples. It is unlikely that these small differences found in some tissues at 48 h postmortem would be detected in an uncontrolled accident situation. We concluded from these findings that these selected tissue metabolites are not useful as long-term postmortem indicators of antemortem adrenergically induced hypermetabolism.     

Investigation of cardiac troponins in postmortem subjects: comparing antemortem and postmortem levels

The limitations of autopsy in the diagnosis of death due to ischemic heart disease are well known. In the living, a simple reliable biochemical assay for cardiac troponins is used in the diagnosis of acute myocardial ischemia. Several studies have investigated the use of biochemical assays for cardiac troponins in postmortem subjects as a means to distinguish between a cardiac and anoncardiac cause of death. All of these studies, however, rely upon assigning subjects to "cardiac" or "noncardiac" death on the basis of a postmortem examination. As postmortem examination does not always accurately distinguish between these two groups, this approach is intrinsically flawed.Our study compares antemortem and postmortem cardiac troponin levels in five subjects. The antemortem samples were retrieved from the hospital biochemistry laboratory after each subject's death. The postmortem samples for each subject were taken from different sites and at different times during the early postmortem period.Erratic results bearing little or no relation to the antemortem cardiac troponin level were obtained for all subjects. Four of the five subjects had raised antemortem troponin levels, although only one had a cardiac cause of death.From this, we conclude that postmortem blood is not a suitable substrate for standard biochemical assays of cardiac troponins, which are designed for use on serum taken from living patients. In addition, the results of our study support the view that elevated cardiac troponins are a marker of serious morbidity and are not specific for cardiac injury as the primary cause of morbidity or mortality.