Age assessment at the time of death based on panoramic radiography

BACKGROUND: The determination of age at the time of death is an important method in forensic anthropology and paleodemography. The possible postmortem investigation of the teeth and jaws enables the determination of age at the time of death, as the bones and teeth are both resistant to degradation in soil and characterized by age-related morphological changes. The aim of this study was to determine whether the age-related changes visible on panoramic radiography correlated with age, and enabled the assessment of individual age. METHODS: Seven radiographic parameters were used in the study: tooth loss, occlusal tooth wear, pulp stones, carious teeth, periapical disease, tooth restoration, and alveolar bone loss associated with periodontal disease. RESULTS: The material comprised 314 dental panoramic tomograms of living patients of both sexes with documented age (18 to 77 years). Multiple regression equations were constructed for the age estimation, including four parameters (the number of missing teeth, the number of intact teeth, the distance of cement-enamel junction from the alveolar ridge, the number of abraded teeth). The nature of data treated by regression analysis required the careful choice of parameters, appropriate functional model for each parameter, and the experience of the investigator. With the four parameters included in equations, the error was +/- 2.55 years. CONCLUSION: This preliminary analysis showed that the conventional regression technique could be appropriate for the age estimation based on panoramic radiography, and that an additional study with a larger sample and on wider population was required.     

Estimating the time of death with infrared tympanic thermometer: a new prospective study in France

International Journal of Legal Medicine - Very few studies are available on the use of infrared tympanic thermometer to estimate the postmortem interval. The purpose is to observe the decrease of...     

果蝇生物钟神经元LNvs参与睡眠调控机制研究进展

睡眠是由生物钟过程以及睡眠内稳态过程共同调控.生物钟过程对昼夜节律的产生与维持十分重要.近年来,随着生活节奏的加快,睡眠问题日益显著,生物钟紊乱则是其中一个重要原因.果蝇作为生物钟研究的前沿模式生物将有助于探究生物钟与睡眠的关系.该文对果蝇生物钟神经元LNvs调控睡眠的研究进展进行了综述,希望有助于解析睡眠的调控机制.     

Estimation of the time of death based on the assessment of post mortem processes with emphasis on body cooling

This paper presents a review of the literature referring to the estimation of the time of death (TOD) over nearly 200 years. Emphasis is put on the development of the methods taking advantage of the decrease in body temperature after death, measured in various body sites. The review is complemented by the first authors’ own experiences on TOD estimation based on post mortem temperature measurements in the eyeball and orbit soft tissues.     

Reliability of the individual age assessment at the time of death based on sternal rib end morphology in Balkan population

This paper analyzes the reliability of the Iscan's sternal rib-ends phase method for the assessment of individual age at the time of death in the Balkan population. The method is based on the morphological age changes of the sternal rib ends. The tested samples consisted of 65 ribs from autopsy cases in the Institute for Forensic Medicine, University of Belgrade, during 1999-2002 (23 females, and 42 males of various ages, ranged from 17-91 years), according to the forensic documents. Significant differences between the real chronological age of the individuals and the values established by the Iscan's method was found, especially in the older categories (phases 6 and 7), in both males and females. The results of the discriminative analysis showed the values of the highest diagnostic relevance for the assessment of age in our population: the change of the depth of the articular fossa, the thickness of its walls, and the quality of the bones.     

Influence of measurement errors on temperature-based death time determination

Temperature-based methods represent essential tools in forensic death time determination. Empirical double exponential models have gained wide acceptance because they are highly flexible and simple to handle. The most established model commonly used in forensic practice was developed by Henssge. It contains three independent variables: the body mass, the environmental temperature, and the initial body core temperature. The present study investigates the influence of variations in the input data (environmental temperature, initial body core temperature, core temperature, time) on the standard deviation of the model-based estimates of the time since death. Two different approaches were used for calculating the standard deviation: the law of error propagation and the Monte Carlo method. Errors in environmental temperature measurements as well as deviations of the initial rectal temperature were identified as major sources of inaccuracies in model based death time estimation.     

Methods for determining time of death

Medicolegal death time estimation must estimate the time since death reliably. Reliability can only be provided empirically by statistical analysis of errors in field studies. Determining the time since death requires the calculation of measurable data along a time-dependent curve back to the starting point. Various methods are used to estimate the time since death. The current gold standard for death time estimation is a previously established nomogram method based on the two-exponential model of body cooling. Great experimental and practical achievements have been realized using this nomogram method. To reduce the margin of error of the nomogram method, a compound method was developed based on electrical and mechanical excitability of skeletal muscle, pharmacological excitability of the iris, rigor mortis, and postmortem lividity. Further increasing the accuracy of death time estimation involves the development of conditional probability distributions for death time estimation based on the compound method. Although many studies have evaluated chemical methods of death time estimation, such methods play a marginal role in daily forensic practice. However, increased precision of death time estimation has recently been achieved by considering various influencing factors (i.e., preexisting diseases, duration of terminal episode, and ambient temperature). Putrefactive changes may be used for death time estimation in water-immersed bodies. Furthermore, recently developed technologies, such as H magnetic resonance spectroscopy, can be used to quantitatively study decompositional changes. This review addresses the gold standard method of death time estimation in forensic practice and promising technological and scientific developments in the field.     

Determination of the time of death by fungal growth

Summary A woman was found in her bedroom, which had been kept at a constant temperature of 12°C, several weeks after she had been murdered. The establishment of the time of death was attempted by examination of fungal development on two parts of her body. Agar slopes were inoculated with the fungal growth present on an eyelid and on the inguinal skin. After 1 day at 20°C, the cultures were incubated at 11–12°C. The cultures were then observed daily until growth was comparable to that on the tissues that had been frozen. By these means it could be established that the victim died at least 18 days before her body was discovered. This, in fact, turned out to be the case. Hyphomycetes growth on a corpse may be helpful in determining the time of death when the event happened 10–20 days earlier, provided that the average surrounding temperature is known.     

Deception by manipulating the clock calibration influences cycle ergometer endurance time in males

It is common for athletes striving to achieve maximal effort to exercise in the presence of a visible clock. It is implicitly assumed that calibration of the clock is normal (i.e. accurate). This study was designed to test the effect of secretly manipulating the clock calibration on maximal effort as measured by endurance times in cycle ergometry. Twelve subjects (6 male and 6 female) each undertook three identical rides to exhaustion on a cycle ergometer. In one the clock was normally calibrated, in another it was calibrated 10% faster, and in the third 10% slower. Tests were conducted double blind and in fully counterbalanced orders within gender. Clocked endurance times were recorded, and later converted to real times. Analysis of clocked times revealed no significant effects. Over all subjects, real endurance times showed a significant calibration effect, being on average 18.3% (73.4 s) longer when the clock ran slow, compared to normal, and 20.5% (80.8 s) longer when compared to fast. Because males exercised significantly longer than females, separate analyses reveal that the calibration effect was only significant in males, 27.7% (143.2 s) and 29.7% (151.2 s), respectively, and present but not significant in females, 1.3% (3.6 s) and 3.8% (10.5 s), respectively. These results suggest that, when deceived by a visible clock running slower than normal, times to exhaustion on the cycle ergometer were significantly longer in male subjects.     

Central monoamines and the death process time (antemortem time) during asphyxia

Summary The changes of the brain monoamines, norepinephrine (NE), dopamine (DA), and serotonin (5-HT), during acute asphyxia, caused by strangulation, anoxia, and drowning, were studied in the mouse.In several asphyxiated animal groups significant linear correlation was found between the level of monoamines, NE, DA, and 5-HT, and the death process times or antemortem times were r=0.50, 0.98 (P<0.05), and 0.57, respectively.It is concluded that the level of brain NE and DA increased in the mouse that died of asphyxia, and the level of 5-HT showed only an apparent decrease in anoxia groups as compared with the control group and showed a twice as high increase in drowning groups. Especially, there was a tendency that the longer the death process times or antemortem times, the higher was the level of DA.     

Post-mortem vitreous ammonium concentrations in estimating the time of death

Summary On a total of 150 specimens of vitreous humor the post-mortem ammonia value was determined by diffusion method. The results established that there existed a regular ammonia increase after a sudden death and that deviating high or low vitreous ammonia values are strongly correlated with the cause of death and with environmental temperature.The ammonia content of the vitreous humor extracted from both eyes at the same and at different post-mortem intervals showed no differences in the concentrations between both specimens sampled at the same moment while an obvious variation in the individual rate of the vitreous ammonia increase is found, especially when hospital cases with antemortem existing disease are concerned.

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Zusammenfassung Der Ammoniakgehalt der Glaskörperflüssigkeit wurde gemessen an insgesamt 150 Entnahmen mit bekannter Todeszeit nach der Diffusionsmethode. Die Ergebnisse zeigen einen regelmässigen postmortalen Anstieg des Ammoniaks in plötzlichen Todesfällen während abweichend höhere und niedrigere Messzahlen sich eng korreliert verhalten mit der Todesursache und dem Aussentemperatur. Doppelbestimmungen des Ammoniakgehalts im Corpus Vitreum beider Augen zu gleicher und verschiedener Leichenzeit vorgenommen erweisen keine Konzentrationsunterschiede in den zu gleicher Zeit entnommenen Proben aber eine merkbare Schwankung in dem individuellen Anstieg der Ammoniakwerte des Glaskörpers, besonders wenn Hospitalfälle mit vorherigen Krankheiten betroffen sind. Wegen der Beschränkung einer notwendigen Selektion in bezug auf Ursache und Plötzlichkeit eines Sterbens ist die Methodik der Ammoniakbestimmung im Glaskörperinhalt angesichts der mit zunehmender Liegezeit wachsenden individuellen Streuung nur als zusätzliches Hilfsmittel zur Todeszeitschätzung verwendbar.

     

Quality of death certification based on the documented underlying cause of death: A retrospective study

BackgroundThe underlying cause of death (UCOD) documented in the death certificate is a cornerstone in the mortality data that has significant impact on national policies, health system, and socioeconomics. However, a wide range of inaccuracies have been reported worldwide and were linked to multiple factors, including sociodemographic development and lack of physician training. Hence, this study aimed to assess the quality of death certification by reviewing the reported UCOD in the death certificate and study the potential factors that might be associated with inaccuracies.MethodsAll in-patient deaths that occurred in the Sultan Qaboos University Hospital from January 2020 to 31 December 2020 were included in this retrospective study. The study investigators reviewed all death certifications that were recorded during the study period for the accuracy of the documented UCOD using a systemic framework recommended by the World Health Organization.ResultsThe study included 384 mortality cases. The mean age at the time of death was 55.7 ± 27.1 years, and 209 (54.3%) cases were men. Approximately 80% (95% confidence interval: 84–76%) of the deceased patients had inaccurate data on the UCOD. Old age (58.1 ± 25.8 vs 46.5 ± 30.1, p < 0.001), death certification by doctor in training (70.8% vs 51.9%, p = 0.001), and admission under the Department of Medicine (68.5% vs 54.4%, p = 0.019) were more common in mortality cases with inaccurate data on the UCOD. Regression analysis confirmed that old age, male sex, and certification by doctor in training were independent predictors of inaccurate data on the UCOD.ConclusionInaccurate data on the UCOD is a prevalent issue in many healthcare settings, especially in the developing countries. Introduction of death certification training in the medical curriculum for medical doctors, implementation of periodic auditing, and provision of feedback are among the evidence-based approaches that are likely to improve the overall accuracy of mortality data.     

Rectal temperature-based death time estimation in infants

In determining the time of death in infants based on rectal temperature, the same methods used in adults are generally used. However, whether the methods for adults are suitable for infants is unclear. In this study, we examined the following 3 methods in 20 infant death cases: computer simulation of rectal temperature based on the infinite cylinder model (Ohno’s method), computer-based double exponential approximation based on Marshall and Hoare’s double exponential model with Henssge’s parameter determination (Henssge’s method), and computer-based collinear approximation based on extrapolation of the rectal temperature curve (collinear approximation). The interval between the last time the infant was seen alive and the time that he/she was found dead was defined as the death time interval and compared with the estimated time of death. In Ohno’s method, 7 cases were within the death time interval, and the average deviation in the other 12 cases was approximately 80 min. The results of both Henssge’s method and collinear approximation were apparently inferior to the results of Ohno’s method. The corrective factor was set within the range of 0.7–1.3 in Henssge’s method, and a modified program was newly developed to make it possible to change the corrective factors. Modification A, in which the upper limit of the corrective factor range was set as the maximum value in each body weight, produced the best results: 8 cases were within the death time interval, and the average deviation in the other 12 cases was approximately 80 min. There was a possibility that the influence of thermal isolation on the actual infants was stronger than that previously shown by Henssge. We conclude that Ohno’s method and Modification A are useful for death time estimation in infants. However, it is important to accept the estimated time of death with certain latitude considering other circumstances.     

丙戊酸钠对小鼠心电改变及死亡时间的影响

目的:研究丙戊酸钠对实验性小鼠心律失常的作用.方法:分别用氯仿和乌头碱诱发小鼠心律失常模型,观察丙戊酸钠的抗心律失常作用.结果:丙戊酸钠对氯仿诱发的小鼠心律失常具有显著的抗心律失常作用;对乌头碱诱发的小鼠心律失常有明显的预防作用.结论:丙戊酸钠对两种方法诱发的心律失常都具有显著的作用.     

Morphology of sweat glands in determining time of death

This study demonstrates post-mortem autolytic alterations in the skin at cellular and subcellular levels and identifies parameters which may assist in determining the time of death in the first few hours post-mortem. Serial skin samples from the ventral surface of the arm were taken at intervals of 3, 6, 9 and 12 h after death in 29 subjects of various ages, with no signs of skin disease; causes of death were various. Three types of tests were performed: cytochemical (hematoxylin-eosin and alcian-PAS), immunohistochemical (S-100, CEA, Cytokeratin, ASM) and ultrastructural (electron microscopy). Electron microscopy proved useful for identifying transformations which were found to be specific for each chronological step considered: reduction of intracellular glycogen in clear cells and reduction of secretory granules in dark cells are typcial signs of the first stage (3 h) after death; mitochondrial dilatation and rarefaction of cristae in clear and dark cells are typical of the second stage (6 h); rarefaction of microvilli in dark and clear cells is a sign of the last stage (12 h). Cytochemistry and immunohistochemistry supply useful information — not for all the chronological stage considered here, but for individual phases (3 h for hematoxylin-eosin and 6 h for alcian-PAS). However, it is particularly important to use the results from all such techniques simultaneously, so that the question of the exact time of death within the first 12 h post-mortem may be more accurately answered.     

Cycles of the uterus mucous membranes and estimation of time of death

In a case where a 27-year-old prostitute was found stabbed to death, histological examination of the uterus mucous membranes was performed to estimate the time of death after a long postmortem interval. The time of menstruation was obtained from a witness statement. Assuming a regular cyclus, the histology of the uterus tissue indicated an early stage of menstruation suggesting that death occurred shortly after the women disappeared.