Diagnosis Of Drowning Research Articles

Application of Diatoms Quantitative Analysis in the Diagnosis of Drowning.

To retrospectively analyze diatom test cases of corpses in water and discuss the value of quantitative analysis of diatoms in the diagnosis of drowning. A total of 490 cases of water-related death were collected. They were divided into drowning group and postmortem immersion group according to the cause of death. Diatoms in lung, liver, kidney tissue and water sample were analyzed quantitatively by microwave digestion-vacuum filtration-automated scanning electron microscopy (MD-VF-Auto SEM) method. The ratios of content of diatoms in lung tissue and water sample (CL/CD) were calculated. The results of diatom test for three organs (lung, liver and kidney) were all positive in 400 cases (85.5%); the content of diatom in lung, liver, kidney tissues, and water samples of drowning group were (113 235.9±317 868.1), (26.7±75.6), (23.3±52.2) and (12 113.3±21 760.0) cells/10 g, respectively; the species of diatom were (7.5±2.8), (2.6±1.9), (2.9±2.1) and (8.9±3.0) types, respectively; the CL/CD of drowning group and postmortem immersion group were (100.6±830.7) and (0.3±0.4), respectively. Quantitative analysis of diatoms can provide supportive evidence for the diagnosis of drowning, and the parameter CL/CD can be introduced into the analysis to make a more accurate diagnosis of drowning.

Comparison of Application of MD-VF-Auto SEM Method and Plankton Gene Multiplex PCR System in the Diagnosis of Drowning.

To compare the application effect of microwave digestion - vacuum filtration - automated scanning electron microscopy (MD-VF-Auto SEM) method and plankton gene multiplex PCR system in the diagnosis of drowning. Lung, liver and kidney tissue of 10 non-drowning cases and 50 drowning cases were prepared for further MD-VF-Auto SEM method analysis and plankton gene multiplex PCR system analysis. The positive detection rate of the two methods in each tissue was calculated. The positive rate of the MD-VF-Auto SEM method detecting diatoms in drowning cases was 100%, and few diatoms were detected in the liver and kidney tissues of 6 non-drowning cases. By using the plankton gene multiplex PCR system, the diatom positive rate of drowning cases was 84%, and all the non-drowning cases were negative. There were significant differences in the positive rate of the liver, kidney tissues between MD-VF-Auto SEM method and plankton gene multiplex PCR system (P<0.05), as well as the total positive rate of cases. However, no significant differences were found in the positive rates of lung tissues (P>0.05). MD-VF-Auto SEM method is more sensitive than plankton gene multiplex PCR system in diatom test. But the plankton gene multiplex PCR system can also detect plankton other than diatoms. Combination of the two methods can provide a more reliable basis for the diagnosis of drowning.

Assisting Role of Pulmonary Hypostasis Phenomenon in Diagnosis of Drowning.

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. 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. 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). The disappearance of pulmonary hypostasis can be used as a specific cadaveric sign to assist in the forensic pathological diagnosis of drowning.

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.

Application of Maxillary Sinus Effusion Detection in Diagnosis of Drowning.

Objective To study the imaging characteristics of maxillary sinus effusion in drowned bodies, to explore its morphological characteristics and value in the diagnosis of the cause of death, and to provide objective evidence to support the study of virtual anatomy of drowning. Methods The 154 postmortem CT examination cases （31 cases of drowning, 123 cases of non-drowning） of Beijing Public Security Bureau Forensic Center in 2019 were collected. The bodies of all cases were scanned by multi-layer spiral CT before double-blind reading by clinical imaging experts. Maxillary sinus of corpses with maxillary sinus effusion in imaging findings was punctured. The detection rate of maxillary sinus effusion was calculated. The CT value and volume of maxillary sinus effusion were measured on 3D DICOM workstation. Results The detection rate of maxillary sinus effusion in the drowning was 100%, the shape was horizontal liquid level, the volume was 1.2-11.2 mL, the CT value was 6.08-19.02 Hu, with an average value of 12.85 Hu. The detection rate of maxillary sinus effusion in non-drowning was 19.51% （24/123）, the shape was wavy or irregular, and there were bubbles inside, the volume was 0.4-13.4 mL, the CT value was 23.68-77.75 Hu, with an average value of 42.08 Hu. The differences in CT value between the two groups had statistical significance. Conclusion The postmortem CT examination method can be used to observe the shape and measure the CT value of the maxillary sinus effusion in the bodies in water, which can be an auxiliary examination method for identification of drowning.

Proteomics in Deaths by Drowning: Diagnostic Efficacy of Apolipoprotein A1 and α-1Antitrypsin, Pilot Study.

Drowning is one of the leading causes of death worldwide. The pathophysiology of drowning is complex and, sometimes, interpretation of the circumstances of death in the autopsy becomes the main source of information in its diagnosis. New advances in medical research, such as proteomics, especially in forensic pathology, are still in the development. We proposed to investigate the application of Mass Spectrometry-based technologies, to identify differentially expressed proteins that may act as potential biomarkers in the postmortem diagnosis of drowning. We performed a pilot proteomic experiment with the inclusion of two drowned and two control forensic cases. After applying restrictive parameters, we identified apolipoprotein A1 (ApoA1) and α-1 antitrypsin as differentially expressed between the two diagnostic groups. A validation experiment, with the determination of both proteins in 25 forensic cases (16 drowned and 9 controls) was performed, and we corroborated ApoA1 higher values in the drowning group, whereas α-1 antitrypsin showed lower levels. After adjusting by confounder factors, both remained as predictive independent factors for diagnosis of drowning (p = 0.010 and p = 0.022, respectively). We constructed ROC curves for biomarkers’ levels attending at the origin of death and established an ApoA1 cut-off point of 100 mg/dL. Correct classification based on the diagnosis criteria was reached for 73.9% of the cases in a discriminant analysis. We propose apolipoprotein A1 (with our cutoff value for correct classification) and α-1 antitrypsin as valuable biomarkers of drowning. Our study, based on forensic cases, reveals our proteomic approach as a new complementary tool in the forensic diagnosis of drowning and, perhaps, in clinical future implications in drowned patients. However, this is a pilot approach, and future studies are necessary to consolidate our promising preliminary data.

Progress in Method and Reliability of Diatom Test in Drowning

The forensic significance of the diatom test in diagnosing death due to drowning has been controversial for a long time as diatoms are detected in the non-drowning cases as well. This false positivity may originate from the ante-mortem as well as postmortem penetration of the diatoms into the bodies. Another problem with the diatom test is the lack of standardization among the different kinds of diatom extraction and identification methods. The author first reviewed the progress in the methods used in the diatom test and then studied the historical arguments in the diagnosis of drowning. Lastly, the research trend in the diatom test since 2000 was evaluated by classifying the manuscripts searched using the keyword “drowning and diatom” on PubMed. Recent studies tend to support the reliability of the diatom test in the diagnosis of drowning when quantitative and qualitative analyses are performed properly with maximum possible reduction in contamination during the preparation of the test samples. Key Words: Diatoms · Drowning · Diagnosis · Research · Review

Automated diatom searching in the digital scanning electron microscopy images of drowning cases using the deep neural networks.

Forensic diatom test has been widely accepted as a way of providing supportive evidences in the diagnosis of drowning. The current workflow is primarily based on the observation of diatoms by forensic pathologists under a microscopy, and this process can be very time-consuming. In this paper, we demonstrate a deep learning-based approach for automatically searching diatoms in scanning electron microscopic images. Cross-validation studies were performed to evaluate the influence of magnification on performance. Moreover, various training strategies were tested to improve the performance of detection. The conclusion shows that our approach can satisfy the necessary requirements to be integrated as part of an automatic forensic diatom test.

Correlation analysis of diatom content in the organs and drowning mediums for the drowning death cases

ABSTRACT Diatoms detected in human organs have been considered as supportive evidence for the diagnosis of drowning. During drowning, the vast majority of diatoms are retained in lung tissues, and only few are transported to distant organs via the bloodstream. In this article, we quantitatively analysed diatom contents in the lung tissues, liver tissues, kidney tissues and the drowning mediums of 165 drowning death cases. The results showed that the diatom content in lung tissues was positively correlated with that in the water samples. However, there was no linear correlation between the diatom content in the liver tissues and that in the water samples. Our study also showed no linear correlation between the diatom content in the kidney tissues and in the water samples. The diatom contents in the liver tissues and kidney tissues were positively correlated, while no linear correlations of diatom contents were found between the liver tissues and lung tissues, and the kidney tissues and lung tissues. These correlations of diatom content in the organs and drowning mediums provide valuable information to interpret and analyse the quantitative results of diatom tests.

Can pulmonary foam arise after postmortem submersion in water? An animal experimental pilot study

It is difficult to differentiate drowning from postmortem submersion. Pulmonary foam can be found in bodies retrieved from water. It is unknown whether foam is a result of drowning or if it also forms after postmortem submersion. We divided deceased piglets into three groups: postmortem saltwater submersion (N = 20), postmortem freshwater submersion (N = 20) and dry-land controls (N = 20). All carcasses underwent endoscopic examination within 24 h of death and the presence of external and internal pulmonary foam was scored. No external foam was detected in the postmortem freshwater or the postmortem saltwater group. Internal foam was seen in 35% of the postmortem freshwater and 40% of the postmortem saltwater group. No external or internal foam was detected in the dry land control group. The literature shows external as well as internal foam in drowned humans. Internal foam is seen in postmortem submersion in the current piglet study and antemortem submersion in the literature in humans, and can therefore not be used to support/refute the diagnosis of drowning. No external foam was present in the postmortem submersed piglets, yet has been described in drowned humans. Hence the presence of external foam in bodies recovered from water may be indicative for drowning. The presence of external foam is a potentially valuable clinical sign in distinguishing drowning from postmortem submersion.

Electrolytes and Biochemical Changes in Cerebrospinal Fluid in Drowning: Experimental Rabbit Model.

The diagnosis of drowning is still a difficult task in forensic science. Biochemical changes in different body fluids have been examined for the identification of drowning. However, none of them alone gives accurate results in the diagnosis of drowning and differentiation of saltwater and freshwater drowning. This study aimed to examine cerebrospinal fluid changes in drowned rabbits. Six groups of rabbits were used including immersed dead rabbits in freshwater or saltwater (as control groups), alive fully conscious rabbits drowned in freshwater and saltwater, and anesthetized rabbits drowned in freshwater and saltwater. Cerebrospinal fluid electrolytes except for potassium levels were significantly higher in rabbits drowned consciously in saltwater than their level in the control group. In rabbit drowned in freshwater, the examined electrolytes decreased significantly. In addition, urea, creatinine, uric acid, glucose, and tumor necrosis factor were different in cases of freshwater and saltwater drowning from those of control rabbits. Electrolytes and biochemical changes of unconscious rabbits drowned in water showed no significant difference from those of control rabbits. Cerebrospinal fluid examination in drowning gives promising results in the diagnosis of drowning. In addition, the differentiation between freshwater and saltwater drowning was possible.

The Potential Diagnostic Accuracy of Autopsy Lung Weights, Lung-Heart Ratio, and Lung-Body Ratio in Drowning Deaths.

Lung weights are often increased in drowning deaths as well as in other types of deaths. Lung weights may also vary with age, sex, and body weight. A variety of methods have been proposed to utilize lung weight data to assist with the diagnosis of drowning. The present study compared lung weight, lung-heart ratio (LH), and lung-body ratio (LB) between 50 consecutive drowning and 50 nonimmersion deaths in order to assess the accuracy in diagnosing drowning. Analysis revealed both LH and LB to be statistically higher in drowning deaths (P < 0.05), with LB being the most robust measurement. However, the overall diagnostic accuracies of lung weight, LH, and LB were poor to fair, and should therefore be used only in conjunction with the other diagnostic criteria.

Detection of Diatoms by a Combination of Membrane Filtration and Transparentness.

Diagnosis of drowning remains a difficult issue in current forensic sciences. A large number of diatoms were lost by removing the supernatant after centrifugation in the conventional forensic diatom test. We developed a novel membrane filtration method to enrich diatoms from samples. A new solution using different ratios of acetic acid and eugenol is prepared to make the membrane transparent. These processes allow the diatom-containing membrane to be visualized and identified easily by light microscopy. The tissues contaminated by water rich in diatoms were detected by the new method for the recovery of diatoms. Eleven drowning cases were analyzed by both the new method and the conventional method to compare the sensitivity of both methods. The recovery of the novel diatom test method was 54.2 ± 23.1%. The positive rate of the novel method has been proven to be superior to the conventional method in the diagnosis of drowning.

Haematic silicon in drowning

The aim of this paper was to evaluate silicon (Si) concentration in human whole ventricular blood as a further potential chemical marker in the diagnosis of drowning. We employed an acidic digestion for the extraction of soluble Si, and an alkaline digestion for the determination of total Si, including particulate matter, both arising from drowning medium. 29 suspected drowning situations, 24 in fresh water (Fw) and 5 in seawater (Sw), were examined. The difference in Si concentration between the left and right ventricular blood (Si ΔL–R) was measured and alkaline Si ΔL–R seems, indeed, a potentially significant complementary tool in the diagnosis of Fw drowning, because insoluble silicon fraction does not undergo hemo-dilution or hemo-concentration, and the ΔL–R is not affected by exogenous factors. In spite of the limited number of cases investigated, a good correlation was observed between the analytical results and the macro-microscopic autoptic findings.

The Drowning Index: Implementation in Drowning, Mechanical Asphyxia, and Acute Myocardial Infarct Cases

Drowning is a diagnosis of exclusion based on circumstantial and autopsy correlation. Sugimura proposed a threshold value of 14.1 for the Drowning Index (DI), the ratio of lung and pleural fluid to spleen weight, as a surrogate marker to diagnose drowning. We questioned the use of DI in diagnosing drowning. We compared DI between three groups--drowning, mechanical asphyxia, and myocardial infarct--seen at Broward MEO from 2008 to 2009. Only 9.4% of 53 drownings exceeded the DI threshold of 14.1, while 30% of 10 mechanical asphyxias and 40% of 10 myocardial infarcts had DI >14.1. Sensitivity for the DI test was <10% and specificity 60-70%. Median DI values for all groups were <10. Mann-Whitney U-test was not statistically significant between groups. The DI is neither sensitive nor specific and lacks any utility in the diagnosis of drowning.

The Distribution of Diatom in the Five Lakes along the Yangtze River

In order to investigate the diatom distribution in the five lakes along the Yangtze River, and discuss the significance for the diagnosis of drowning. 6 water samples were collected in the five lakes along Yangtze River in June, 2012. Subsequently, The genus and the quantity of the diatoms in the water samples were investigated using scanning electron microscopy (SEM). The result showed us that there was significant difference between the waters sampled from the different sites . These data on diatom distribution are helpful to the diagnosis of the cause of the death as well as to the determination of the drowning site in cases of drowning. Therefore, it is necessary to develop the database of diatoms in more extensive water bodies for the forensic diagnosis of drowning in the future.

Silicon determination in human ventricular whole blood: A possible marker of drowning

This article presents the first results demonstrating that total silicon trace concentration in human ventricular whole blood may be used as a further marker in the diagnosis of drowning. The difference in silicon content between the left and right ventricles was significantly higher for drowning cases than that from individuals who had not drowned. These findings were in full agreement with autoptic responses, supporting silicon as a marker of freshwater drowning. The procedure entails an alkaline microwave-assisted digestion using tetramethylammonium hydroxide (TMAH) in the presence of H2O2 followed by dynamic reaction cell inductively coupled plasma mass spectrometry (DRC–ICP–MS) detection, whose accuracy was obtained for Seronorm whole blood reference material. Satisfactory recoveries (91–98%) were gained on whole ventricular blood, with a silicon content lower than the method detection limit (MDL), spiked at 5 to 7μgg−1 with materials consistent with drowning media constituents, that is, freshwater plankton (CRM [certified reference material] 414), silicon dioxide, diatomaceous earth powder, and a silicon standard solution. Good within-lab reproducibility (4–10%) and sensitivity (MDL=0.46μgg−1) were achieved as well. The procedure was applied to blood samples from 18 different real cases of death.

Detection of diatom in formalin-fixed tissue by proteinase K digestion

The diatoms detection has been proposed to be useful in the diagnosis of drowning. Enzymatic digestion of unfixed lung tissues and other organs with proteinase K is widely employed to detect diatoms. Handling unfixed organs or blood from the bodies with some infectious diseases could prove to be dangerous. In this study, we examined the application of enzymatic digestion for diatom detection to formalin-fixed lung obtained at autopsy. Furthermore, we assessed the effect of hydrogen peroxide on the contamination of the lung specimen with foreign bodies inhaled in the course of drowning, smoking, or air pollution. Formalin-fixed lung was heated in 0.01 M Tris–HCl buffer (pH 7.5) containing sodium dodecyl sulfate (SDS) (tissue lysis-buffer), with or without glycine. Thereafter, the lung was subjected to enzymatic digestion with proteinase K. A part of formalin-fixed or unfixed samples digested with proteinase K were incubated with hydrogen peroxide at 80 °C for 6 h or 12 h, while the residues were processed without incubation. Formalin-fixed samples heated in tissue lysis-buffer with glycine could be digested with proteinase K; further, the number and proportion of diatoms detected in both formalin-fixed and unfixed samples were observed to be similar. The results suggest that enzymatic detection of diatoms can be applied to formalin-fixed organs by heating the samples in glycine-containing tissue lysis-buffer. As the use of formalin-fixed tissue for diatom detection can decrease risk of contamination by pathogenic organisms during the course of enzymatic digestion, the method presented in this study would be beneficial, to some extent, to individuals performing diatom analysis. Moreover, our results suggest that archival organs stored in formalin solution could be available in diatom detection over a long time-period following autopsies. Clearer image of diatoms was observed in the specimen incubated with hydrogen peroxide for 6 h, in which inhaled foreign bodies were discolored, than those not subjected to incubation. Therefore, incubation of sample digested with hydrogen peroxide in the limited time would be helpful for quantitative and qualitative diatom analysis.

Detection of diatom in formalin-fixed organs by enzymatic digestion

The detection of diatoms has been proposed to be useful in the diagnosis of drowning. Enzymatic digestion of unfixed lungs and other organs is widely used to detect diatoms. In the present study, we examined the application of enzymatic digestion for diatom detection in formalin-fixed organs obtained at autopsy. Furthermore, we assessed the effect of hydrogen peroxide on contamination of the lung specimen with foreign bodies inhaled in the course of drowning or as a result of smoking or air pollution. Unfixed lung was digested with proteinase K for 2 d and centrifuged; the supernatant was then removed. On the other hand, formalin-fixed lung samples were boiled in Tris–HCl buffer containing sodium dodecyl sulfate (SDS) and then subjected to enzymatic digestion. A portion of formalin-fixed or unfixed samples digested with proteinase K was incubated with hydrogen peroxide at 80 °C and mounted on a slide, while the remaining portion was processed without incubation. Samples incubated with hydrogen peroxide showed clearer image of diatoms than those not incubated with hydrogen peroxide; this is because the inhaled foreign bodies were discolored in the former samples. Therefore, incubation of digested samples with hydrogen peroxide would be helpful for quantitative and qualitative analyses of diatoms.

Protozoaires cilies et thanatologie

Different ciliated protozoa are observed by the immersion of dead bodies in soft water. In death from drowning a ciliated Tetrahymena kind was discovered whose size and hemotactism facilitate in a priviliged way the penetration in the internal medium through pulmonary channels. Diagnosis in blood was easy by putting this organism in culture. This method had an astonishing power of reproduction. This search fortunately completes the series about diatoms by means of corroboration on the diagnosis of drowning.