Inferring Postmortem Submersion Interval in Rats Found in Water Based on Vitreous Humor Metabolites / 法医学杂志

OBJECTIVES@#The metabolomics technique of LC-MS/MS combined with data analysis was used to detect changes and differences in metabolic profiles in the vitreous humor of early rat carcasses found in water, and to explore the feasibility of its use for early postmortem submersion interval (PMSI) estimation and the cause of death determination.@*METHODS@#The experimental model was established in natural lake water with 100 SD rats were randomly divided into a drowning group (n=50) and a postmortem (CO2 suffocation) immediately submersion group (n=50). Vitreous humor was extracted from 10 rats in each group at 0, 6, 12, 18 and 24 h postmortem for metabolomics analyses, of which 8 were used as the training set to build the model, and 2 were used as test set. PCA and PLS multivariate statistical analysis were performed to explore the differences in metabolic profiles among PMSI and causes of death in the training set samples. Then random forest (RF) algorithm was used to screen several biomarkers to establish a model.@*RESULTS@#PCA and PLS analysis showed that the metabolic profiles had time regularity, but no differences were found among different causes of death. Thirteen small molecule biomarkers with good temporal correlation were selected by RF algorithm. A simple PMSI estimation model was constructed based on this indicator set, and the data of the test samples showed the mean absolute error (MAE) of the model was 0.847 h.@*CONCLUSIONS@#The 13 metabolic markers screened in the vitreous humor of rat corpses in water had good correlations with the early PMSI. The simplified PMSI estimation model constructed by RF can be used to estimate the PMSI. Additionally, the metabolic profiles of vitreous humor cannot be used for early identification of cause of death in water carcasses.

Review and Prospect of Diagnosis of Drowning Deaths in Water / 法医学杂志

Drowning is the death caused by asphyxiation due to fluid blocking the airway. In the practice of forensic medicine, it is the key to determine whether the corpse was drowned or entered the water after death. At the same time, the drowning site inference and postmortem submersion interval (PMSI) play an important role in the investigating the identity of the deceased, narrowing the investigation scope, and solving the case. Based on diatoms testing, molecular biology, imaging and artificial intelligence and other technologies, domestic and foreign forensic scientists have done relative research in the identification of the cause of death, drowning site inference and PMSI, and achieved certain results in forensic medicine application. In order to provide a reference for future study of bodies in the water, this paper summarizes the above research contents.

Research Progress on Estimation of Postmortem Submersion Interval / 法医学杂志

Postmortem interval （PMI） estimation is one of the most important and difficult academic tasks in forensic sciences. Due to the influence of the corpse itself and the water environment, corpses in water have unique corruption phenomenon and laws. Based on the experience of traditional PMI studies of corpses on land, forensic practitioners across the world have proposed a variety of practical methods for estimating postmortem submersion interval （PMSI）. This paper summarizes the literatures related to PMSI in recent years, and introduces methods to infer PMSI according to the phenomenon of corpses, the development of insects, the succession pattern of aquatic organisms, and the changes of other physical and chemical indexes of corpses, in order to provide some reference for the study of PMSI of corpses in water.

Research Progress of Aquatic Corpse Decomposition and Postmortem Submersion Interval Estimation / 法医学杂志

Human corpses can be found in a variety of aquatic environments. The decomposition of corpses in aquatic environments is different from those on land. A large number of factors influence the decomposition process in water, therefore postmortem submersion interval （PMSI） is difficult to estimate. To date, while studies on aquatic corpses are obviously fewer than those on terrestrial corpses, there are many problems in practical work. This review summarizes the stages and influencing factors of aquatic corpse decomposition, and introduces the relevant research progress of PMSI estimation based on decomposition stages, postmortem phenomena, aquatic insects, biofilm, and physical and chemical methods, in order to provide reference for aquatic decomposition researches and practices.

Nature helps to solve the crime â Diatoms study in case of drowning death.

Nature is everywhere surrounding us in different form. It includes single cell structure to extremely complex, living or non living, substance or creature. One of the important part of nature is diatom - submersion of body into water is known since ages. Diatoms study in case of drowing death is very useful for forensic investigators. It is one of the best example in which nature helps to solve the crime. In present article, we discussed about diatoms, diagnosis of drowning death and length of submersion of body in water with help of diatoms, collection, identification and preservation of diatoms for forensic analysis.

Treatment of Space Loss Caused by Submerged Mandibular Second PrimaryMolar.

Submersion is a clinical term describing a tooth depressed below the occlusal plane. In this case report, we present treatment of a patient who had totally submerged primary maxillary second molar, which caused impaction of the second premolar and space loss in the maxillary arch due to tipping of adjacent teeth. A 19 yr old female was referred to the Department of orthodontics. Intraoral examination revealed left mandibular second primary molar was localized lingually being almost covered by gingiva and adjacent teeth inclined closing the space of the related tooth completely. Panaromic radiograph demonstrated that mandibular second premolar was impacted. Based on clinical and radiographic findings mandibular primary second molar was extracted. A pre- Adjusted Edgewise appliance (MBT prescription 022” slot) was used for creating space for the impacted second premolar. Eruption began spontaneously 6 months later.

The Risk of Cervical Spine Injuries among Submersion Patients in River

PURPOSE: Recently, the American Heart Association recommended that routine cervical spine protection in submerged patients was not necessary, except in high-energy injury situations. However, until now, this recommendation has few supportive studies and literatures. This retrospective study was performed to demonstrate the risk of cervical spine injury in patients who had been submerged in a river. METHODS: Seventy-nine submerged patients who visited St. Mary's Hospital between January 2000 and December 2005 were included in this retrospective study. We investigated and analyzed the victim's age, sex, activity on submersion, mental status and level of severity at admission, prognosis at discharge, associated injuries, and risk group by using the medical records and cervical spine lateral images. According to the activity on submersion, victims were classified into three groups: high risk, low risk, and unknown risk. The reports of radiologic studies were classified into unstable fracture, stable fracture, sprain, degenerative change, and normal. RESULTS: The patients'mean age was 36.8 yrs, and 54% were males. Of the 79 patients, adult and adolescent populations (80%) were dominant. Jumping from a high bridge (48%) was the most common activity on submersion and accounted for 52% of the high-risk group. The Glasgow coma scale at admission and the cerebral performance scale at discharge showed bimodal patterns. The results of the radiologic studies showed one stable fracture, one suspicious stable fracture, and 18 sprains. The incidence of cervical spine fracture in submerged patients was 2.5% in our study. The incidence of cervical spine injury was higher in the high-risk group than it was in the low-risk group, especially in the jumping-from-high-bridge subgroup; however this observation was not statistically significant. No other factors had any significant effect on the incidence of cervical spine injury. CONCLUSION: Our study showed that even submerged patients in the high risk group had a low incidence of cervical spine fracture and that the prognosis of a patient did not seem to be influenced by the cervical spine fracture itself.

Prediction of Poor Outcome in Coma Patients Resuscitated from Cardiac Arrest due to Submersion

PURPOSE: This study was conducted to predict poor outcomes in coma patients resuscitated from cardiac arrest due to submersion. METHODS: We retrospectively investigated 27 submersion victims who were comatose for more than 6 hours after cardiac arrest. Vegetative state and death (GOS 1-2) were classified as poor outcomes whereas all other outcomes (GOS 3-5) were classified as good outcomes. Demographic, clinical, laboratory, radiologic, eletrophysiologic, and treatment variables were evaluated for their usefulness in predicting outcome. RESULTS: Of the 27 patients, 9 (33%) presented with good outcomes. Among the many variables, a GCS score of 3-5 in the first 24 hours, absence of pupillary reactions in the first 24 hours or on day 3, motor response to pain flexion or less (M1 - 3) or no motor response to pain (M1) in the first 24 hours or on day 3, bilateral absence of N20 on SEP showed significant differences between the two outcome groups (p<0.05). Prognostic factors with 100% specificity for prediction of poor outcome included absence of pupillary reactions in the first 24 hours or on day 3, no motor response to pain (M1) on day 3, and bilateral absence of N20 on SEP. CONCLUSION: The factors including chest radiography, body temperature, and laboratory findings which were associated with submersion showed no significant differences between the good and the poor outcome groups. Absence of pupillary reactions in the first 24 hours or on day 3, no motor response to pain (M1) on day 3, and bilateral absence of N20 on SEP helped predict poor outcome in submersion patients resuscitated from cardiac arrest.

Clinical Feature of Submersion Injury in Adults / 결핵

BACKGROUND: Drowning represents the third most common cause of all accidental deaths worldwide. Although few studies of submersion injury were done in Korea, the subjects were mainly pediatric patients. The purpose of this study is to describe the clinical feature of submersion injury in adults. METHODS: The medical records of 31 patients with submersion injury who were >15 years of age and admitted to Kyungpook National University Hospital from July 1990 to March 2003 were retrospectively examined. RESULTS: The most common age-group, cause, and site of submersion accidents in adults were 15-24 years of age, inability to swim, and river followed by more than 65 years of age, drinking, and public bath respectively. The initial chest radiographs showed bilaterally and centrally predominant distribution of pulmonary edema at lung base in about 90% of patients with pulmonary edema represented by submersion injury but at only upper lung zone in 10%. Eventually, 25 patients (80.6%) survived without any neurologic deficit and 2 patients (6.5%) with significant neurologic deficit, and 4 patients (12.9%) died. Age, arterial gas oxygenation, and mental status among baseline variables showed significant difference for prognosis. CONCLUSIONS: More than 65 years of age, drinking, and occurrence in public bath were relatively important in submersion injury of adults, and the successful survival of 80.6% of patients suggests that cardiopulmonary resuscitation should be intensively done in even adults.

Clinical Analysis of Submerged Patients Treated at an Emergency Medical Center near the Han River

BACKGROUND: There are approximately 2,400 drowning deaths reported every year in Korea, but there are few good reports about submerged patients visiting the emergency room, so this study was designed to investigate the clinical characteristics and outcomes of submerged patients treated at an emergency medical center near the Han river. METHODS: A retrospective review of 123 cases of submerged patients admitted to our emergency medical center over a 5 year period from 1996 to 2000 was conducted. RESULTS: Among the 123 submerged patients, there were 66 males and 57 females, and their mean age was 33.18. The common cause of submersions was a suicide attempt, followed by lack of attention, unknown etiology, and water sports such as swimming. Most of the patients were transported to ER by 119 ambulance. In-hospital CPR was performed on 27(22%) cases. At initial ECG rhythm of these cases, asystole was noted in 25 patients; VF and pulseless electrical activity, respectively, were noted in two others. Prehospital CPR had been performed on all in-hospital CPR cases except 2. Prolonged ROSC after succesful CPR was noted in 13 cases. The mean duration of CPR was 26 minutes. Five patients survived after CPR. Their neurologic outcomes were assessed on CPC(cerebral performance category). Three patients were categorized in CPC1, the other two patients were categorized in CPC3 and CPC4. CONCLUSION: Submerged patient's visits to emergency medical center near the Han river were most frequent in summer for suicide purposes. Drowned patients were more hypothermic than other cardiac arrest cases, and resulted in better outcome even with prolonged arrest time, if they were given appropriate prehospital CPR and aggressive in-hospital resuscitation.