Human osteology: key to the sequence of events in a postmortem shooting.

Forensic anthropologic examination of human skeletal remains found when a field was plowed provides evidence of both perimortem trauma, suggesting cause of death, and of subsequent shooting of the disarticulated skeleton. The case exemplifies the application of the specialized skills and knowledge of the physical anthropologist to determination of the postmortem sequence of events.     

Minimally invasive postmortem telebiopsy

For the past 10 years, medical imaging techniques have been increasingly applied to forensic investigations. To obtain histological and toxicological information, tissue and liquid samples are required. In this article, we describe the development of a low-cost, secure, and reliable approach for a telematic add-on for remotely planning biopsies on the Virtobot robotic system. Data sets are encrypted and submitted over the Internet. A plugin for the OsiriX medical image viewer allows for remote planning of needle trajectories that are used for needle placement. The application of teleradiological methods to image-guided biopsy in the forensic setting has the potential to reduce costs and, in conjunction with a mobile computer tomographic scanner, allows for tissue sampling in a mass casualty situation involving nuclear, biological, or chemical agents, in a manner that minimizes the risk to involved staff.     

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.     

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.     

Fatal combined intoxication with new antidepressants. Human cases and an experimental study of postmortem moclobemide redistribution.

Three cases are presented in which death was caused by suicidal intoxication with moclobemide in combination with a selective serotonin reuptake inhibitor. Both antidepressant drug types are considered to be relatively safe with regard to lethal overdose. However, the combination may cause the serotonin syndrome, a condition with a high mortality rate. In one of the cases, there was clinical information consistent with the serotonin syndrome, in the two other cases, there was no information of the clinical course. Postmortem redistribution of the selective monoamine oxidase inhibitor moclobemide was investigated in a rat model. Postmortem concentrations in blood from the vena cava and the heart were found to be in good accordance with antemortem concentrations. Postmortem concentrations in vitreous humour and various tissues were also measured. The apparent volume of distribution was calculated to be 0.95 +/- 0.10 l/kg, which is in the same range as that reported in man.     

脑组织与其相关分析推断死亡时间的研究进展

推断死后间隔时间(postmortem interval,PMI)一直是法医学鉴定中需要解决的重要问题之一.可用于推断PMI的尸体检材有很多种,脑组织因其独特的解剖学位置与生理功能,是推断PMI的重要检材之一.本文从三个方面将根据脑组织推断PMI的方法进行综述,包括了通过脑组织的温度、形态特点等尸体现象推断PMI;通过...     

Flualprazolam distribution in postmortem samples

The constant emergence of novel psychoactive substances is troubling to both public health officials and legislators. Additionally, sufficient data collection for each new compound can take months up to years. Flualprazolam, a triazolobenzodiazepine, quickly garnered attention as a sedative drug that likely expresses adverse reactions similarly to alprazolam. This study focuses on the distribution of flualprazolam in multiple common postmortem matrices. Central blood, vitreous humor, liver homogenate, brain homogenate, gastric contents, and urine samples from death investigation cases were quantitated when available. Samples were screened with liquid chromatography quadrupole time-of-flight with limit of detection set at 4 ng/ml and quantitated on liquid chromatography tandem mass spectrometry, with concentration range from 4 to 256 ng/ml. From August 2018 to September 2020, 24 central blood samples were quantitated for flualprazolam. Central bloods of 22 cases had concentrations above the limit of quantitation. The average flualprazolam central blood concentration was 16.3 ng/ml with a median of 9.95 ng/ml (4.24–48.0). Additional analyses for unconjugated flualprazolam were performed on at a total of 15 urine samples ( = 14.4, 4.07–36.1 ng/ml), 23 brain homogenates ( = 23.2, 3.99–69.3 ng/g), 23 liver homogenates ( = 50.7, 13.6–156 ng/g), five vitreous humor samples ( = 7.70, 4.03–12 ng/ml), and 12 gastric contents samples ( = 0.36, 0.02–2.51 mg). The cause of death for 13 of the 24 cases listed flualprazolam as a contributing factor of death.     

Automatic screening in postmortem toxicology

The systematic analysis of postmortem samples is one of the most challenging tasks in forensic toxicology. For determining cause of death, analysis of different tissues can be indispensable. Automation of these analyses would increase reproducibility and therefore lead to more reliable and comparable results. Recent developments in analytical toxicology and the availability of automation devices for various analytical stages, such as sampling, preliminary testing, sample extraction, chromatographic separation, identification, and data processing are examined and discussed. At present only parts of the analytical procedure have been automated-however, the goal should be the integration of these parts into a single, continuous process. Currently, only one "fully-automated" procedure for the comprehensive screening of blood and urine (excluding sample pretreatment, which remains separate) has been published. But it can be expected that automation of analytical procedures in forensic toxicology will indeed progress, even with regard to the very complex screening of postmortem samples.     

Chloroquine distribution in postmortem cases

Chloroquine concentrations in blood and tissues were examined in overdose and non-overdose cases to determine appropriate ranges for interpretation. Twenty-nine literature overdose cases and 8 non-overdose literature cases were compared with this laboratory's findings. The results indicate significant postmortem redistribution of chloroquine. Combining this laboratory's results and the literature results indicates that using a liver concentration of 150 mg/kg as a cutoff between overdose and non-overdose concentrations properly identified 30 of the 34 published cases containing liver chloroquine and 19 of the 20 presented cases.     

Study of postmortem blood circulation

The objective of this work was to study the postmortem redistribution of blood volumes and its influence of the distribution of substances of different molecular weight (194.2 and 150,000 Da). Lipiodol Ultrafluide, Omnitrast, or a radioisotopic mixture of aminohippuric acid and human IgG were injected into the left ventricle of a total of 20 rabbits divided into three groups. Our results demonstrate the importance of related factors, including left ventricular postmortem contraction, the arterial vascular bed, diffusion processes connected to the physicochemical characteristics of the substances, and the anatomical distribution of the vessels. Postmortem diffusion of aminohippuric acid to the urine was observed.     

Preanalytic aspects in postmortem toxicology

The preanalytic phase has been recognized to have a substantial role for the quality and reliability of analytical results, which very much depend on the type and quality of specimens provided. There are several unique challenges to select and collect specimens for postmortem toxicology investigation. Postmortem specimens may be numerous, and sample quality may be quite variable. An overview is given on specimens routinely collected as well as on alternative specimens that may provide additional information on the route of administration, a long term or a recent use/exposure to a drug or poison. Autolytic and putrefactive changes limit the selection and utility of specimens. Some data from case reports as well as experimental investigations on drug degradation and/or formation during putrefaction are discussed. Diffusion processes as well as postmortem degradation or formation may influence ethanol concentration in autopsy specimens. Formalin fixation of specimens or embalmment of the corpse may cause considerable changes of initial drug levels. These changes are due to alterations of the biological matrix as well as to dilution of a sample, release or degradation of the drug or poison. Most important seems a conversion of desmethyl metabolites to the parent drug. Some general requirements for postmortem sampling are given based on references about specimen collection issues, for a harmonized protocol for sampling in suspected poisonings or drug-related deaths does not exist. The advantages and disadvantages of specimen preservation are shortly discussed. Storage stability is another important issue to be considered. Instability can either derive from physical, chemical or metabolic processes. The knowledge on degradation mechanisms may enable the forensic toxicologist to target the right substance, which may be a major break down product in the investigation of highly labile compounds. Although it is impossible to eliminate all interfering factors or influences occurring during the preanalytic phase, their consideration should facilitate the assessment of sample quality and the analytical result obtained from that sample.     

Immunohistochemical studies on postmortem lividity

An immunohistochemical investigation of postmortem lividity was performed to illuminate localization of hemoglobin (Hb) and the mechanism of fixed lividity. The fixed lividity was defined as an unfading phenomenon by thumb finger pressure. Skin specimens were taken from 68 autopsy cases 7.5–336 h (2 weeks) postmortem. Localization of Hb of the specimens was examined by a labeled streptabidin biotin (LSAB) method using polyclonal (rabbit antihuman hemoglobin antibody) and monoclonal (mouse anti-human hemoglobin monoclonal antibody) antibodies. Positive staining for Hb was observed in various sites of the skin, i.e. in only intravascular erythrocytes, in vascular walls and perivascular tissue including sweat glands and sebaceous glands, in the dermal connective tissue, and in almost all of skin tissue except the horny layer. The diffusion of Hb into skin tissue was observed in 20 of 41 displaceable lividity cases (49%) and 11 of 27 fixed lividity cases (41%). Compared to displaceable lividity, superficial plexi in fixed lividity were filled with erythrocytes, which were markedly immunodetected. These findings support the hypothesis that the fixation of lividity is not due to diffusion of Hb into skin tissue but hemoconcentration in blood vessels.     

Spectrophotometric evaluation of postmortem lividity

Under low ambient temperatures normally bluish postmortem lividity adopts a bright red or pink colour due to resaturation of haemoglobin with O2. The most important differential diagnosis in the presence of pink hypostasis is carbon monoxide poisoning. To answer the question if objective measuring methods allow differentiation of hypostasis with regard to cold exposition or carbon monoxide poisoning, spectrophotometric measurements were performed and the colorimetric measures as well as the spectral reflectance curves of the postmortem lividity were determined. The colorimetric measures CIE-L*a*b* showed similar values for all bright red livores mortis; differentiation between CO intoxication and cold exposition was not possible. Reflectance curves of pink hypostasis after cold storage showed the typical pattern of O2-rich blood with reflectance minima at wavelengths 541 nm and 576 nm and a reflectance maximum at 560 nm. Pink hypostasis because of carbon monoxide poisoning showed a shift of the reflectance maximum toward 555 nm and a flattened curve in all cases with COHb concentrations exceeding 52%, whereas these changes were not regularly observed with lower COHb levels.     

Fluvoxamine distribution in postmortem cases

Four postmortem cases are reported in which the selective serotonin re-uptake inhibitor fluvoxamine was identified. Fluvoxamine was detectable using a standard alkaline drug screen, chromatographed well using a HP-1 column, and did not require derivitization for quantitation. Two of the cases reported were drug intoxications; fluvoxamine was only an incidental finding in the other 2 cases. Central and peripheral blood values are reported, as well as antemortem blood, bile, vitreous fluid, and urine values. No solid organs were obtained in any of the cases. Quantitations were performed using both an analytical standard and a fluvoxamine tablet for the preparation of calibrators. A comparison of quantitative values was made to evaluate the feasibility of using a tablet as the drug source for the preparation of calibrators when a pure reference material is unavailable. Postmortem peripheral blood concentrations ranged from approximately 0.5 mg/L in a case of suicidal shooting to approximately 6 mg/L in a case of drug overdose. Evidence of postmortem redistribution was noted in the only case for which both central and peripheral blood were obtained. Quantitations using an extracted drug tablet for the preparation of calibrators correlated well with quantitations using a pure reference material.     

Factors affecting postmortem tooth loss

Unassociated human bones are a particular problem during the exhumation of mass graves and a factor that limits anthropological and paleopathological analyses from archaeological contexts. Extensive anthropological literature has focused on the complex taphonomic factors that influences bone assemblages, but little attention has been paid to postmortem tooth loss and factors affecting this process. The following study focuses upon the influence of different factors on postmortem tooth loss. Three samples were investigated in the study: a medieval church cemetery containing 110 individual skeletal remains, and two samples from a series of mass graves made within the same time period in 1999, containing 402 bodies. The frequency of postmortem tooth loss was analyzed relative to postmortem interval for each sample, excavation methods, age distribution, and presence of bone loss associated with periodontal disease. Our results indicate that the degree of alveolar bone loss significantly affected both antemortem and postmortem tooth loss and that the frequency of postmortem tooth loss has the strongest correlation to time since death. These findings suggest that additional care should be taken when exhuming remains from older contexts.     

Decision-making concepts in postmortem identification

Concepts of the decision-making process in mass casualty identification are discussed. The importance of the correct data type, the correct data format, and the appropriate decision paths are emphasized. Also discussed are the hidden dangers in the use of changeable physical characteristics for sorting factors. A suggested decision process for use in postmortem identification is outlined, along with its application to computer-assisted identifications.     

大鼠尸体组织电阻抗的死后变化及与死亡时间的关系

目的探讨躯体组织的电阻抗的死后变化规律，寻找推断死后经过时间的新方法。方法用阻抗测量仪测量大鼠胃壁、腹壁、躯干、胸部、腹部、腹部皮肤、头皮等处不同死后经过时间的电阻抗。结果大鼠躯体组织的电阻抗随着死后经过时间的延长存在规律性变化。这些结果告诉我们，有望通过测量死后人体躯体组织的电阻抗，利用其死后变化规律，推断人体死后经过时间。     

Centipede inflicted postmortem injury.

We here report the first case of postmortem injury caused by a centipede. An old man was found dead in his bedroom. The death was estimated to be due to intracranial hemorrhage and to have occurred two days before the police inspection. A centipede about 12 cm long emerged from a subcutaneous cavity on the victim's forearm. Obviously, the centipede had dug the cavity on the intact skin. A police inspector was bitten by the centipede, so he stepped on the centipede on the floor. The exudate from the insect was identified to be derived from the victim's blood.