A comparative assessment of time-consuming and laborious diatom analysis：Brief experimentation with suggestion of automatic identification.

Diatom testing is considered a useful method for providing supportive evidence for the diagnosis of drowning in forensic pathology. However, various factors remain controversial for recognizing diatoms, such as being time-consuming and laborious and influencing the consistency of the results. Given the absence of precise and well-defined studies on this subject, this study aimed to determine the relationship between the ability to identify diatoms and researchers with different technical backgrounds. A total of 55 samples from 18 cases, including water, lungs, liver, and kidneys, were treated using the microwave digestion-vacuum filtration-automated scanning electron microscopy (MD-VF-Auto SEM), which was used to compare diatom analyses among three groups of well-trained forensic pathologists (FPs), trained junior employees (JEs), and new trainees (TEs). In addition to achieving similar accuracy of positive findings from drowning cases, counting efficiency was evaluated based on taxonomy records and counting time after viewing more than 5500 diatom images. In contrast to the higher counting efficiency of the JE group than that of the TE group, we observed a statistically significant difference (p < 0.05) in the diatom classification between these two groups. Based on our experiments, an efficient analysis for automatically identifying and classifying diatoms is urgently required.

The significance of evaluating sphenoid sinus fluid by postmortem computed tomography in cases of drowning.

PURPOSE: In cases of drowning, the presence of sphenoid sinus fluid is a non-specific autopsy finding. However, studies have reported that fluid accumulation in the paranasal sinuses is more commonly observed in drowning victims. Furthermore, some laboratory tests, such as diatom and electrolyte analysis, can serve as supplementary diagnostic tools for diagnosing drowning. Therefore, accurate sphenoid sinus fluid sampling is an important aspect of an autopsy in suspected drowning cases. The aim of this study was to identify the significance of evaluating sphenoid sinus fluid by PMCT images in cases of drowning. METHODS: We retrospectively reviewed 54 drowning victims who underwent PMCT and forensic autopsy. Fluid volume in the sphenoid sinus was measured using a graduated syringe during autopsy and a three-dimensional (3D) workstation based on PMCT images was used for the purpose of comparison. The Mann-Whitney U test and Spearman's rank correlation coefficient was used to evaluate statistically significant differences and correlations. Additionally, a Bland-Altman plot was employed to assess the agreement between PMCT and autopsy. RESULTS: The median volume was 1.65 (range 0.00-12.4) ml and 1.55 (range 0.00-7.00) ml in the PMCT and autopsy, respectively, showing a statistically insignificant difference (p = 0.294) and a significant correlation (Rs = 0.896). In 35 cases, the PMCT overestimated the fluid volume more than the autopsy, whereas in 14 cases, the PMCT underestimated the fluid volume. No fluid was identified in seven cases during the autopsy, whereas in five patients, no fluid was found in both PMCT and autopsy. By analyzing the Bland-Altman plot, a bias of 0.73 ± 1.4 ml and limits of agreement ranging from -2.04 to 3.51 ml were observed for sphenoid sinus fluid volume measurements. CONCLUSIONS: Based on the limitations of traditional fluid volume measurement in the sphenoid sinus during autopsy, we propose the utilization of PMCT volumetric analysis prior to autopsy as a means to enhance the detection of sphenoid sinus fluid in cases of drowning.

Potential of photoautotrophic microbial organisms in deciphering forensic issues.

In forensic pathology, solving the crime mystery of death due to drowning still remains a challenging issue. The amalgamation of autopsy findings and comparative study of diatoms recovered from the victim's body organs and suspected drowning site help to decipher the cause of death due to drowning or post-mortem immersion. Since the correct interpretation of the cause of death is an important criterion to provide justice to the victim, therefore, the main objective of our study is to throw light on the application of photoautotrophic micro-algal organisms, known as Diatoms, in solving seven cases of victims whose bodies were recovered from various water bodies of Himachal Pradesh, India. The diatom test was conducted by using reverse aqua regia solution (15 ml HNO3: 5 ml HCl) on the bone marrow extracted from the organs and water samples respectively. The informative outcomes of the experimental analysis demonstrated that the diatom test acts as a beneficial adjunct to solve drowning-related crimes where the exact cause of death remains hidden even after performing an autopsy of the victims. The protocol followed by the authors can be used conveniently to recover diatoms from bone marrow as well as from water samples. Our results showed that the maximum cases were of death due to accidental drowning but for one case of suicidal drowning in extremely cold water.

The possibilities and limitations of comparative diatomaceous analysis for confirming or excluding the site of an incident - Case studies.

Diatoms (Bacillariophyta) are unicellular photosynthetic organisms commonly occurring in aquatic habitats on Earth. Their autecology makes them almost perfect indicators of environmental conditions and so have high potential for use in forensics. Both eurytopic and stenotopic species are important in site identification: eurytopic forms due to their abundance, and stenotopic forms due to their narrow range of tolerance to environmental conditions. Their presence can hence provide a clear insight into an ecosystem and its microhabitats. The diatoms are useful as significant indicator in diagnosing of drowning. However, to definitively link a corpse with the place where it was found and to indicate whether this was also the crime scene, it is essential that any comparative diatomaceous analyses are performed correctly. The following study presents selected cases in which a comparative diatomaceous analysis was performed. In all cases, the biological samples secured during the autopsy were compared with environmental samples collected from the site of the cadaver disclosure. Our findings show both the possibilities and limitations of using this method in forensics. These forensic investigations need close collaboration between coroners and diatomology experts. It is crucially important to reveal whether the place of corpse finding is the same as the place of drowning.

Assisting Role of Pulmonary Hypostasis Phenomenon in Diagnosis of Drowning.

OBJECTIVES: To study the phenomenon of pulmonary hypostasis in corpses of various causes of death, and to explore the potential value of this phenomenon in assisting forensic pathological diagnosis of drowning. METHODS: A total of 235 cases with clear cause of death through systematic autopsy were collected from January 2011 to June 2021 in Guangzhou. According to the location of body discovery, the cases were divided into the water body group (97 cases) and the non-water body group (138 cases), and the water body group was further divided into the water drowning group (90 cases) and the water non-drowning group (7 cases). Non-water body group was further divided into the non-water drowning group (1 case) and the non-water non-drowning group (137 cases). Three senior forensic pathologists independently reviewed autopsy photos to determine whether there was hypostasis in the lungs. The detection rate of pulmonary hypostasis was calculated. RESULTS: The detection rate of pulmonary hypostasis in the water drowning group (90 cases) was 0, and the negative rate was 100%. The detection rate of pulmonary hypostasis in the water non-drowning group (7 cases) was 100% and the negative rate was 0. The detection rate of pulmonary hypostasis in the water body group and in the non-water body group (after excluding 2 cases, 136 cases were calculated) was 7.22% and 87.50%, respectively. There were statistically significant differences in the detection rate of pulmonary hypostasis between water body group and non-water body group, and between water drowning group and water non-drowning group (P<0.05). CONCLUSIONS: The disappearance of pulmonary hypostasis can be used as a specific cadaveric sign to assist in the forensic pathological diagnosis of drowning.

Use of cadaveric vitreous humor as an innovative substrate for diatoms research and forensic diagnosis of drowning.

The search for diatoms is the test that most of all may contribute to the forensic diagnosis of drowning. Diatoms can be extracted through different methods, which are all complex and long. In this preliminary study, we assessed human vitreous humor as an innovative substrate on which to research diatoms. Sampling and analyses were performed on 3 groups of 10 corpses each. The first one was composed of drowned victims. The second one of victims of traffic accidents with subsequent projection in water; based on the severe traumatic injuries reported at autopsy, we considered such victims as ideally assimilable to bodies immersed in water postmortem. The third group was composed of subjects who died for natural causes and without any relationship with water. The vitreous humor was centrifugated and cytocentrifuged and spotted on two different histological slides: one was left blank and the other one was assessed with hematoxylin and eosin staining. Microscopic observation successfully revealed diatoms in all cases of the first group; in the second group diatoms were not detected in 6 cases; in the third group, no diatoms at all were observed. Diatoms were always qualitatively and quantitatively consistent with those found in the corresponding viscera and waters, which had been investigated through classical acid digestion. Our analyses have demonstrated that the vitreous humor behaves in a completely similar way to the other viscera in cases of drowning. Although further investigations are necessary, vitreous humor has proved to be an innovative, suitable, and reliable substrate for the forensic research of diatoms.

Deaths in Bathtubs in Japan: Forensic and Clinical Implications.

In Japan, deaths in bathtubs or bathtub deaths are frequently investigated as unnatural deaths. About 19,000 bathtub deaths occur annually in Japan. This pattern of death has become a social issue in forensic pathology and emergency medicine and public health. It is assumed that the death of an adult by drowning in a bathtub cannot be avoided due to disturbance of consciousness. The PubMed database was used for literature search using the retrieval words, "bathing "OR" bathtub "AND" submersion "OR" drowning "OR" death "OR" cardiopulmonary arrest". From the epidemiological characteristics and pathophysiological findings of bath mortality in Japan, three etiologies of impaired consciousness have been proposed: acute ischemic heart failure, heatstroke, and blood pressure fluctuation. Moreover, other causes such as epilepsy and alcohol or drug intake cannot be ignored as potential risks for death in a bathtub. It is also important to note the possibility of suicide and, although extremely rare, homicide in a bathtub. Despite research, the exact causal relationship between bathtub bathing and death remains unclear. Further, the cause of death by postmortem investigation is not always easily determined. Hence, it is desirable to carry out a field survey of causes of death, including bathing conditions, and, wherever possible, a complete autopsy survey. An exclusion of critical cases such as crime-related death, suicide, drug poisoning, and carbon monoxide poisoning is optimal. Of the many hypotheses about the causes of bathtub mortality, the most consistent hypothesis will be medically inferred from the death history, case findings, and test results.

Histopathological differentiation of drowning in freshwater and saltwater in rats: forensic point of view / Diferenciación histopatológica de ahogamiento en agua dulce y agua salada en ratas: punto de vista forense

SUMMARY: The postmortem diagnosis of death by drowning is one of the most difficult issues in forensic pathology. We investigated possible evidence differentiating saltwater drowning from freshwater drowning by histopathological changes in brain, heart, lungs, liver, and kidneys tissues. A cross section descriptive study was carried out on eighteen 12-week-old male Wistar rats; they were divided equally into 3 groups. Group 1: control group; Group 2: death by drowning in freshwater; Group 3: death by drowning in saltwater. Immediately after death, all tested organs were removed and fixed for histopathological examination. The brain of freshwater group depicted degenerated neurocytes with dystrophic changes in the form of shrunken cell, pyknotic nuclei and deeply eosinophilic cytoplasm. The heart showed clear evidence of myocyte injuries in saltwater drowning compared to the control and freshwater groups. The kidneys of rats drown in saltwater revealed more glomerular destruction with no differences in tubulo-interstitial changes in comparison with those drown in freshwater. In the lungs, the changes in freshwater were restricted to the alveoli, and the bronchial changes were more distinctive in saltwater. No disturbed liver architecture was seen in both test groups, however hydropic degeneration, congested vessels, and sinusoids were more distinct in saltwater group. In conclusion, diagnostic differentiation between fresh and saltwater drowning was reliable in rats' lungs and heart with minimal differentiation in liver, kidneys, and brain. Further studies of drowning with different staining techniques will help to clarify the potential role of histopathological changes in body organs as indicator of drowning.

RESUMEN: El diagnóstico post mortem de muerte por ahogamiento es uno de los temas más difíciles de la patología forense. Investigamos la posible evidencia que diferencia el ahogamiento en agua salada del ahogamiento en agua dulce por cambios histopatológicos en los tejidos del cerebro, el corazón, los pulmones, el hígado y los riñones. Se realizó un estudio descriptivo de corte transversal en dieciocho ratas Wistar macho de 12 semanas de edad; se dividieron por igual en 3 grupos. Grupo 1: grupo control; Grupo 2: muerte por ahogamiento en agua dulce; Grupo 3: muerte por ahogamiento en agua salada. Inmediatamente después de la muerte, se extirparon todos los órganos analizados y se fijaron para el examen histopatológico. El cerebro del grupo de agua dulce mostró neurocitos degenerados con cambios distróficos en forma de células encogidas, núcleos picnóticos y citoplasma profundamente eosinofílico. El corazón mostró una clara evidencia de lesiones de miocitos en los ahogamientos en agua salada en comparación con los grupos de control y de agua dulce. Los riñones de ratas ahogadas en agua salada revelaron una mayor destrucción glomerular sin diferencias en los cambios túbulo-intersticiales en comparación con las ahogadas en agua dulce. En los pulmones, los cambios en agua dulce se restringieron a los alvéolos y los cambios bronquiales fueron más distintivos en agua salada. No se observó una arquitectura hepática alterada en ambos grupos de prueba, sin embargo, la degeneración hidrópica, los vasos congestionados y los sinusoides fueron más distintos en el grupo de agua salada. En conclusión, la diferenciación diagnóstica entre ahogamiento en agua dulce y salada fue confiable en los pulmones y el corazón de las ratas con una diferenciación mínima en el hígado, los riñones y el cerebro. Estudios adicionales de ahogamiento con diferentes técnicas de tinción ayudarán a aclarar el papel potencial de los cambios histopatológicos en los órganos del cuerpo como indicador de ahogamiento.

A comparative study of pleural effusion in water area, water temperature and postmortem interval in forensic autopsy cases of drowning.

Japan is surrounded by the sea and is also a mountainous country with many rivers. Japan has the second- highest rate of deaths caused by drowning in the world. Pleural effusion (PE) is one of the major findings at autopsy. It is found in approximately 80% of drowning mortalities and is observable for a relatively long postmortem interval (PMI). We focused on the amount of pleural fluid in drowning cases, discussed the relationship of PE with the drowning environment, water temperature, and postmortem interval, and established more simple and practical criteria for the diagnosis of drowning. We measured the weight of the lungs, PE, and their sum as the intrathoracic (IT) weight (total weight of lungs + pleural effusion), and calculated the PE ratio [(PE weight/IT weight) × 100]. A total of 130 drowning deaths diagnosed through forensic autopsies were investigated in this study. The cases were classified by drowning environment (freshwater, brackish water, and seawater), water temperature (under 20 °C, more than 20 °C), and postmortem interval (less than 1 day, 1-3 days, more than 3 days). The present study demonstrated that the PE ratio may be more effective for the diagnosis of drowning. Moreover, the accumulation of PE is affected by drowning environment, water temperature, and PMI. Collectively, it is important to assess the PE ratio and consider these factors in autopsy cases of victims found in water.

Muscular Hemorrhages Around the Scapula Provide Insight on the Manner of Asphyxia: A Preliminary Study.

ABSTRACT: Muscular hemorrhages around the scapula that are caused by upper extremity motion are rarely reported in cases other than drowning. We examined differences in the frequency of muscular hemorrhages around the scapula and stratified them by the cause of death. Muscular hemorrhages were mostly noted in cases of drowning (118/185, 63.8%), followed by cases of asphyxia (23/44, 52.3%). In addition, muscular hemorrhages around the scapula were found in cases of ligature strangulation (8/11, 72.7%), manual strangulation (2/3, 66.7%), choking (11/14, 78.6%), and traumatic asphyxia (2/2, 100%). Muscular hemorrhages were not found in cases of hanging or environmental suffocation, possibly because of the short time interval preceding the loss of consciousness. The distribution of muscular hemorrhages was similar in choking and drowning cases. Muscular hemorrhages due to strangulation were mainly unilateral, whereas those due to choking and drowning were mainly bilateral. During all types of asphyxia, muscular hemorrhages around the scapula were considered to be the result of conscious, active upper extremity motion. Because the frequency and laterality of muscular hemorrhages around the scapula differed based on the type of asphyxia, our findings provide insights into the manner of asphyxia that could be used to aid in the identification of homicidal hangings.

Determining the effect of water temperature on the T1 and T2 relaxation times of the lung tissue at 9.4 T MRI: A drowning mouse model.

Japanese individuals have a unique culture of soaking in a bathtub, and forensic pathologists have experienced fatal cases due to drowning. However, T1 and T2 relaxation times of a drowning lung are poorly documented. In the present study, we investigated the relationship between drowning water temperature and T1 and T2 relaxation times of drowning lung tissues at 9.4 T MRI (Bruker, BioSpec94/20USR). The mice used as animal drowning models were directly submerged in freshwater. Water temperature was set to 8 °C-10 °C (cold), 20 °C-22 °C (normal), 30 °C, and 45 °C. The regions of interest (ROIs) on the axial section of the third slice were set at the central and peripheral areas of each-the left and the right-lung. T1 relaxation times measured immediately after death differed by the presence or absence of soaking water, except in case of cold water temperature. In the drowning groups, T1 relaxation time showed a linear dependency on water temperature. By contrast, T2 relaxation time was almost constant regardless of the presence of drowning under the same temperature condition; when compared in the lung areas of the same individuals, the times were uniformly reduced in drowning models. To minimize the effects of hypostasis and decomposition, we performed measurements immediately after death and were able to determine the noticeable difference in drowning water temperature. These results may be useful for qualitative assessments of a drowning lung and may serve as a basis when imaging the human body during forensic autopsy cases.

Macromorphological findings in cases of death in water: a critical view on "drowning signs".

Death in water is a challenging issue in forensic pathology since from natural death to homicide all circumstances of death in water are conceivable. Therefore, the correct interpretation of all abnormal autopsy findings is important. In order to determine a death by drowning, numerous internal and external signs of drowning are already described. However, these are supposed to be influenced by various factors reducing their significance and evidence. Moreover, the autopsy of water corpses often reveals further pathological findings that should not be underestimated for determining the cause of death. The aim of this study was to set frequencies of the observed drowning signs in context to the forensic literature and to identify possible influencing factors. In this study, we observed that pathological organ changes of the cardiovascular system were significantly more common in corpses after shortened (atypical) drowning processes than in classical drowned victims. Furthermore only a complete formation of external foam, immediately after the corpse's recovery, was exclusively found in drowning victims. All other drowning signs were either also observed in non-drowning deaths in water or no information could be provided with reasonable assurance. In addition, many of the examined drowning signs were negatively affected by prolonged postmortem intervals, putrefaction, or resuscitation attempts. It can be concluded from our analysis that morbidity is an important factor in deaths in water. Morbidity can support a death by drowning in case of incidents in water. For the examined drowning signs, no high diagnostic certainty could be observed. Nevertheless, these findings can increase their diagnostic value-if forensic physicians take influencing factors into consideration.

Postmortem findings in Magellanic penguins (Spheniscus magellanicus) caught in a drift gillnet.

BACKGROUND: Penguin interaction with gillnets has been extensively reported in the Atlantic and Pacific Oceans, and is considered a major conservation threat. Among penguin species, Magellanic penguins (Spheniscus magellanicus) are currently considered of great concern, particularly in Brazil, where they are highly susceptible to gillnet bycatch. Nevertheless, information about drowning-associated microscopic findings in penguins is limited. RESULTS: We describe the anatomopathological findings of 20 Magellanic penguins that drowned after getting entangled in a drift gillnet while wintering along the Brazilian shelf and washed ashore still enmeshed in Santa Catarina, Brazil. All 20 birds (19 juveniles and 1 adult; 18 females and 2 males) were in good body condition. Major gross findings were abrasion, bruising, and local erythema and edema of the wings, multiorgan congestion, jugular vein engorgement, pulmonary edema and hemorrhage, splenomegaly and hepatomegaly, fluid in the trachea, serous bloody fluid in the lungs, gastrointestinal parasites (nematodes, cestodes and trematodes), and debris in the stomach. The most common histopathological findings were cerebral and pulmonary congestion, pulmonary edema, splenic histiocytosis, lymphoid splenic hyperplasia, acute splenitis, extramedullary hepatic hematopoiesis, and parasitic enteritis. Although unspecific, the observed multiorgan congestion and pulmonary edema are consistent with previous reports of drowning in birds and may be indicative of this process. CONCLUSIONS: Drowning may be a challenging diagnosis (e.g., carcass decomposition, predation), but must be considered as a differential in all beach-cast seabird postmortem examinations. To the authors' knowledge this is the largest anatomopathological study based on microscopic examination in drowned penguins.

The Diagnostic Value of the Changes in the Renal Glomerulus in the Postmortem Diagnosis of Freshwater Drownings.

Drowning is one of the major causes of unintentional injury death worldwide. As there are no pathomorphological findings specific to the diagnosis of drowning, definitive postmortem diagnosis of drowning continues to be a significant problem in forensic medicine. This study aims to present an additional diagnostic sign in cases of freshwater drowning by investigating the histopathological changes of renal tissue in the postmortem diagnosis of freshwater drowning. For this purpose, 103 cases were investigated in which the causes of death were freshwater drowning (n = 45), traffic accidents (n = 33) and acute myocardial infarction (n = 25). Renal corpuscular structures of selected cases were examined stereologically and histopathologically. Renal corpuscle diameter, renal corpuscle surface area, glomerular tuft surface area, and Bowman space were calculated by stereological method. When compared with the glomeruli of the control group, renal corpuscle diameter, renal corpuscle surface area, glomerular tuft surface area, and Bowman space values of kidney tissues of all freshwater drowning cases were found to be decreased (P < 0.001). These changes may be considered as an essential histopathological finding in postmortem diagnosis of freshwater drowning cases.

Diagnosis of drowning using postmortem computed tomography combined with endoscopic autopsy: A case report.

RATIONALE: Postmortem forensic imaging technologies provide a noninvasive/minimally invasive approach for imaging of internal organ structures of the human body to detect injuries, diseases, and other morphologic changes. Currently, postmortem forensic imaging methods have been widely used in determination of the cause of death. However, these methods do not allow histologic examinations. Endoscopic autopsy emerged in the 1990s. Thoracoscopy and laparoscopy are mainly used to examine organs and tissues in the thoracic and abdominal cavity. Target tissues are also sampled for histologic examination. By combining postmortem forensic imaging with endoscopic autopsy, comprehensive examination of the corpse, organs, and sampling for histologic examination can be carried out. PATIENT CONCERNS: A 34-year-old woman was witnessed jumping into the river, sinking after struggling in the water. The body was found 24 hours later and confirmed with no vital signs. No preexisting medical conditions were known. DIAGNOSIS, INTERVENTIONS, AND OUTCOMES: Postmortem computed tomography, target coronary postmortem computed tomography angiography, and endoscopic autopsy were performed before conventional autopsy. Laparoscopic examination was used to examine the abdominal organs. The diaphragm and pericardium were cut open from the abdominal cavity to allow access to the examination of lungs and heart. Tissue samples were collected from various organs for histologic examination, and a diatom test was carried out on lung samples. Postmortem computed tomography revealed fluid in the paranasal sinuses, airways, stomach, and duodenum; emphysema aquosum; and mosaic pattern of the lung parenchyma. Endoscopic examination additionally detected Paltauf spots. The results were consistent with those of conventional autopsy. Histologic examination revealed pulmonary congestion, pulmonary edema, pulmonary emphysema, pulmonary hemorrhage, and congestion in multiple organs such as the liver, spleen, and kidneys. Diatoms were detected in lung tissues, which were identical in morphology to diatoms in water samples collected from the scene. The cause of death was determined as drowning. CONCLUSION: Combining forensic imaging and endoscopic autopsy for postmortem examination yields a more comprehensive and scientific finding, and the combination is minimally invasive and more acceptable to the family members. This method can be used as an alternative for conventional autopsy under specific circumstances.

Structural abnormalities in the human diaphragm in drowning and hanging deaths: preliminary results.

PURPOSE: Previous experiments in rats have indicated that there are histological changes in skeletal muscle in drowning deaths; these changes include muscle fibers that contain ragged red fibers (RRF). The purpose of this study was to examine whether these changes also occur in humans. METHODS: Histologic and histochemical examinations of three muscles (diaphragm, pectoralis, and psoas) were performed on 24 cadavers with three different causes of death: 8 drowning, 8 hanging, and 8 sudden cardiac disease. Muscle samples were stained with hematoxylin-eosin, MGT, nicotinamide adenine dinucleotide-tetrazolium reductase, succinate dehydrogenase, ATPase, and acid phosphatase via standard staining procedures. RESULTS: There were statistically significant differences in the detection of RRFs in these cohorts. Additionally, several other cytoarchitectural changes (whorled and core-like fibers) were observed in the diaphragm in the drowning cohort and to a lesser extent in the hangings. These structural abnormalities were not observed in the sudden cardiac disease deaths, thus suggesting a common mechanism for the production of these muscular changes that is not shared in the cardiac death group. The mechanism is most likely intense hypoxia and mechanical trauma of the respiratory muscles in the setting of active blood circulation with intense muscle contraction. CONCLUSIONS: Our results confirmed that there are histological changes in the diaphragm in drownings and, to a lesser extent, in hangings.

An unusual pattern of post-mortem injury caused by Australian fresh water yabbies (Cherax destructor).

A 67-year-old woman with a history of previous cerebrovascular accidents who was confined to a wheel chair drowned in a pond in a public park. Features compatible with drowning included congestion and edema of the lungs with prominent hemolytic staining of the intima of the aortic root. Minor bruises and abrasions were identified. Toxicology was negative. An additional unusual finding was that of patterned symmetrical injuries to the earlobe and pinna of both ears. The injuries consisted of small irregular areas of skin loss that were sometimes linear and parallel and had the appearance of animal nibble marks. Given the presence in the pond of numerous Australian fresh water yabbies (Cherax destructor), and no other predators, it appeared that the injuries had been caused by post mortem feeding by these crustaceans. This case therefore extends the range of animals that may be involved in post mortem predation that may be encountered in cases of freshwater drowning/immersion in an Australian context, with a specific pattern of injury focused on the ear lobes.

Case-specific characteristics of pink teeth in dental autopsies - A systematic review.

The cadaveric alterations that derive from the decomposition of the human body are often investigated and examined in medical autopsies together with any other evidence of thanatological interest. This study aimed to systematically review case-specific characteristics of dental autopsies that reported the pink tooth phenomenon (PTP). The review was performed in October/2018 and followed PRISMA and Cochrane guidelines. Seven databases were searched as primary study sources (PubMed, Scopus, LILACS, SciELO, Web of Science, Science Direct and Embase) and three (OATD, Open Grey and Open Thesis) were searched for "grey literature". Only descriptive studies were collected, namely case reports and case series. The risk of bias among the studies was assessed with The Joanna Briggs Institute Critical Appraisal tool. From each case, the sex and age of the victims were registered, together with the place of body recovery, time of death, cadaveric status, cause of death, and number and position of pink teeth. Additionally, a supplemental quantitative analysis was conducted within a sampled subgroup. Poisson regression with robust variance was used to analyze relative risks of presenting pink teeth according to age and tooth position. Eleven studies out of 1004 were eligible. In total 71 cases of cadavers with pink teeth were reported. Two (2.81%) victims had unknown sex, while 17 (23.95%) were females and 52 (73.24%) were males. The victims were aged between 4 and 85 years (mean age 31.13 ±â€¯13.32). Dental autopsies registered 331 pink teeth (163 anterior, 87 premolars and 81 molars). The age did not influence on presenting an additional pink tooth, regardless of tooth position (p > 0.05). Forensic dentists must be aware of pink teeth in dental autopsies. This is an unspecific phenomenon and must not be misinterpreted in medico-legal investigations.

New insights into odontological exploration of drowning using rat model - A pilot study.

Dental forensics for the resolution of unnatural death remains an underdeveloped field. Accordingly, an experimental study was conducted with six to seven months old Wistar rats that were drowned in order to identify key postmortem features and pattern of dental decomposition. The visual, structural and elemental changes were assessed periodically. Based on mode of death, they were designated as SB (euthanized and soil buried), FWD (fresh water drowned) and SWD (sea water drowned). Postmortem features as well as the structural and elemental patterns of decomposition of teeth were analyzed with Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive Spectroscopy (EDAX) periodically for two months. The periodic observation of elemental changes in the teeth of SB, FWD and SWD rats allowed us to derive an equation using linear regression analysis to relate the degree of dental decomposition with the time since death. The difference in pattern of surface deterioration was also observed. The present findings could provide a better knowledge in resolving unnatural deaths and supporting evidence for legal prosecution.

The persistent problem of drowning - A difficult diagnosis with inconclusive tests.

Although the diagnosis of drowning may appear straightforward the reality is that it is sometimes one of the most difficult in forensic pathology. To begin with, there is no universal agreement on what constitutes drowning with some definitions using the term in the absence of a lethal outcome. Next are the significant problems that arise in finding immersed bodies and in assessing the death scene. Prolonged post mortem intervals are associated with artefactual modifications of the body from putrefaction and post mortem animal predation. Both of these may create and disguise injuries. The absence of pathognomonic pathological features at autopsy and the presence of potentially life threatening underlying organic illnesses complicate determination of both the cause and manner of death. There may even be no autopsy findings to indicate that immersion had occurred. Finally, the unreliability of laboratory tests with significant overlap with control cases where death had no association with immersion presents further problems. Thus lethal drowning remains a complex event that requires the use of a wide variety of information sources, not just data gleaned from the dissection table.