Survey on the Construction Status of Forensic Virtual Autopsy Laboratory and the Applicability of Laboratory Accreditation / 法医学杂志

OBJECTIVES@#To survey the development status and actual needs of virtual autopsy technology in China and to clarify the applicability of forensic virtual autopsy laboratory accreditation.@*METHODS@#The questionnaire was set up included three aspects：(1) the current status of virtual autopsy technology development; (2) the accreditation elements such as personnel, equipment, entrustment and acceptance, methods, environmental facilities; (3) the needs and suggestions of practicing institutions. A total of 130 forensic pathology institutions were surveyed by online participation through the Questionnaire Star platform.@*RESULTS@#Among the 130 institutions, 43.08% were familiar with the characteristics of virtual autopsy technology, 35.38% conducted or received training in virtual autopsy, and 70.77% have establishment needs (including maintenance). Relevant elements were suitable for laboratory accreditation.@*CONCLUSIONS@#Virtual autopsy identification has gained social recognition. There is a demand for accreditation of forensic virtual autopsy laboratory. After the preliminary assessment, considering the characteristics and current situation of this technology, China National Accreditation Service for Conformity Assessment (CNAS) can first carry out the accreditation pilot of virtual autopsy project at large comprehensive forensic institutions with higher identification capability, and then CNAS can popularize the accreditation in a wide range when the conditions are suitable.

Research Progress on Molecular Changes in Pulmonary Hypoxia and Cause of Death Identification in Mechanical Asphyxia / 法医学杂志

Lung is the largest organ of the respiratory system. During hypoxia, pulmonary cells undergo rapid damage changes and activate the self-rescue pathways, thus leading to complex biomacromolecule modification. Death from mechanical asphyxia refers to death due to acute respiratory disorder caused by mechanical violence. Because of the absence of characteristic signs in corpse, the accurate identification of mechanical asphyxia has always been the difficulty in forensic pathology. This paper reviews the biomacromolecule changes under the pulmonary hypoxia condition and discusses the possibility of application of these changes to accurate identification of death from mechanical asphyxia, aiming to provide new ideas for related research.

Research Progress on Estimation of Postmortem Interval Based on Ocular Tissues Structure / 法医学杂志

Estimation of postmortem interval (PMI) is one of the important research contents in forensic pathology, and it has always been the focus and hot spot of research work. In recent years, scholars at home and abroad have made some research progress in estimating PMI by using ocular tissue. After death, the changes of cornea, aqueous humor, iris, lens, vitreous humor and retina all show time sequence change rule highly related to PMI. This paper reviews the research progress of PMI estimation based on the morphological, biochemical, molecular and genetic material changes of different ocular tissue structures after death, and discusses the existing problems and development trends.

Forensic Pathological Diagnosis of Acute and Old Myocardial Infarction Using Fourier Transform Infrared Spectroscopy / 法医学杂志

OBJECTIVES@#Fourier transform infrared spectroscopy (FTIR) was used to analyze myocardial infarction tissues at different stages of pathological change to achieve the forensic pathology diagnosis of acute and old myocardial infarction.@*METHODS@#FTIR spectra data of early ischemic myocardium, necrotic myocardium, and myocardial fibrous tissue in the left ventricular anterior wall of the sudden death group of atherosclerotic heart disease and the myocardium of the normal control group were collected using hematoxylin-eosin (HE) and immunohistochemistry (IHC) staining as a reference, and the data were analyzed using multivariate statistical analysis.@*RESULTS@#The mean normalized spectra of control myocardium, early ischemic myocardium and necrotic myocardium were relatively similar, but the mean second derivative spectra were significantly different. The peak intensity of secondary structure of proteins in early ischemic myocardium was significantly higher than in other types of myocardium, and the peak intensity of the α-helix in necrotic myocardium was the lowest. The peaks of amide Ⅰ and amide Ⅱ in the mean normalized spectra of myocardial fibrous tissue significantly shifted towards higher wave numbers, the peak intensities of amide Ⅱ and amide Ⅲ were higher than those of other types of myocardium, and the peak intensities at 1 338, 1 284, 1 238 and 1 204 cm-1 in the mean second derivative spectra were significantly enhanced. Principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) showed that FTIR could distinguish different types of myocardium.@*CONCLUSIONS@#FTIR technique has the potential to diagnose acute and old myocardial infarction, and provides a new basis for the analysis of the causes of sudden cardiac death.

Research Progress of DNA-Based Technologies for Postmortem Interval Estimation / 法医学杂志

In criminal investigations, postmortem interval (PMI) is important information to be inferred in homicide investigations, as well as the focus and the difficulty in forensic pathology research. Because the DNA content in different tissues is relatively constant and shows changes regularly with the extension of PMI, it has become a research hotspot of PMI estimation. This paper reviews the recent progress of PMI estimation technologies including DNA-based single cell gel electrophoresis, image analysis, flow cytometry, real-time fluorescence quantitative PCR and high-throughput sequencing, hoping to provide references for forensic medicine practice and scientific research.

Forensic Analysis of 9 Cases of Sudden Unexpected Death in Epilepsy / 法医学杂志

OBJECTIVES@#To analyze the case, scene and forensic pathological characteristics of sudden unexpected death in epilepsy (SUDEP), to provide a practical basis for forensic identification.@*METHODS@#A total of 9 autopsy cases of SUDEP were collected. The basic information of the cases, the scene characteristics, the forensic pathological changes, the common drugs and antiepileptic drug test results, and pericardial fluid biochemical test results were analyzed.@*RESULTS@#All of the 9 cases were male epilepsy patients died during sleep at night, the age of death was (37.1±8.6) years, and the course of epilepsy was (21.3±5.6) years. Six corpses were in prone position and three in left lateral position. The hemorrhage of the sternocleidomastoid muscle, sternal thyroid muscle and sternohyoid muscle were found with 8 cases, 5 cases and 4 cases, respectively, all of them were unilateral. Six cases had bilateral hemorrhage of pectoralis minor muscle. Brain edema, phagocytosis of frontotemporal neurons and gliosis, cardiac fibers bend in wavy patterns and eosinophilic staining enhancement, pulmonary edema, pulmonary congestion, alveolar hemorrhage, pulmonary small bronchiole wall shrinking, tubular proteinuria and pancreatic parenchymal hemorrhage were the common histopathological changes. The biochemical test results of pericardial fluid indicated that there were myocardial ischemic damage.@*CONCLUSIONS@#Young male, early onset, long course of disease, sleep in the prone position, poor drug compliance or combination, epileptic seizure may be the risk factors of SUDEP. Cardiac dysfunction and respiratory depression might be the main death mechanism of SUDEP.

CiteSpace-Based Visualization Analysis of Forensic Research in China from 2010 to 2019 / 法医学杂志

OBJECTIVES@#To analyze the research status of forensic medicine in China from 2010 to 2019, obtain the development trend of forensic medicine and explore the hotspots and research frontiers.@*METHODS@#The forensic medical academic papers published on China National Knowledge Infrastructure (CNKI) database from 2010 to 2019 were collected. CiteSpace 5.7.R1, an information visualization analysis software, was used to analyze publication organizations, authors, keywords, and other elements.@*RESULTS@#The majority of the research institutions were universities, provincial and ministerial scientific research and forensic institutions. Forensic pathology was still an important branch of forensic medicine and a popular research direction. The "polymorphism" and "Y chromosome" had been the research hotspots in recent years. "Medical damage" and "standard" were the most novel studies.@*CONCLUSIONS@#In order to provide scientific basis and research direction for forensic research, this paper analyzes the cooperation network, research hotspots and research innovation in forensic research.

Forensic Research Progress on Postural Asphyxia / 法医学杂志

In recent years, the increase in the number of cases of postural asphyxia has gradually attracted the attention and discussion of forensic scientists domestically and internationally, but a systematic, comprehensive and recognized expert consensus and identification standard has not been established at home and abroad. This paper reviews the case characteristics, occurrence, mechanism of death, and identification criteria of postural asphyxia, to provide reference for future research.

Research Progress of Forensic Diagnosis Approaches of Early Acute Myocardial Infarction / 法医学杂志

The postmortem diagnosis of acute myocardial infarction (AMI), especially the postmortem diagnosis of early AMI that died immediately after onset or within 1 hour, has always been a difficulty in forensic identification. This article reviews the forensic application of diagnosis and analysis methods for AMI postmortem diagnosis including autopsy imaging, histomorphology, immunohisto-chemistry, biochemical marker and molecular biology diagnosis, and explores the feasible scheme of early postmortem diagnosis in AMI.

Research Status and Prospects of Non-Traumatic Fat Embolism in Forensic Medicine / 法医学杂志

In the practice of forensic pathology, fat embolism is one of the common causes of death, which can be divided into two categories: traumatic and non-traumatic. Non-traumatic fat embolism refers to the blockage of small blood vessels by fat droplets in the circulatory blood flow caused by non-traumatic factors such as underlying diseases, stress, poisoning and lipid metabolism disorders. At present, it is believed that the production of non-traumatic fat embolism is related to the disturbance of lipid metabolism, C-reactive protein-related cascade reaction, the agglutination of chylomicron and very low-density lipoprotein. The forensic identification of the cause of death of non-traumatic fat embolism is mainly based on the case, systematic autopsy, HE staining and fat staining, but it is often missed or misdiagnosed by forensic examiners because of its unknown risk factors, hidden onset, the difficulty of HE staining observation and irregular implementation of fat staining. In view of the lack of attention to non-traumatic fat embolism in forensic identification, this paper reviews the concepts, pathophysiological mechanism, research progress, existing problems and countermeasures of non-traumatic fat embolism, providing reference for forensic scholars.

Effects of Digestive Temperature and Time on Diatom Test / 法医学杂志

OBJECTIVES@#To study the effects of temperature and time for diatoms digestion and find out suitable digestive temperature and time.@*METHODS@#Eighty pieces of liver tissues were collected, each piece of tissue was 2 g, and 2 mL Pearl River water was added to each piece of tissue. The digestion temperature was set at 100 ℃, 120 ℃, 140 ℃, 160 ℃, 180 ℃ and the digestion time was set at 40, 50, 60, 70, 80 min. The liver tissue and water mixture were divided into 8 portions in each group. All the samples were tested by microwave digestive - vacuum filtration - automated scanning electron microscopy method. The quantity of diatom recovered and the quality of residue on the membrane were recorded.@*RESULTS@#When the digestion time was set to 60 min, there were statistically significant differences in the number of diatoms recovered at different temperatures (P<0.05). The maximum number of diatoms recovered was (28 797.50±6 009.67) at 140 ℃, and the minimum residue was (0.60±0.28) mg at 180 ℃. When the digestion temperature was set at 140 ℃, there were statistically significant differences in the number of diatoms recovered at different digestion times (P<0.05). The number of diatoms recovered was the highest at 40 min, it was up to (20 650.88±1 950.29), and the residue quality of each group had no statistical significance among different digestion time groups(P>0.05).@*CONCLUSIONS@#The effect of diatom digestion is related to temperature and time. When the digestion temperature was 140 ℃ and the digestion time was 40, 50 and 60 min, it is favorable for diatom test.

Assisting Role of Pulmonary Hypostasis Phenomenon in Diagnosis of Drowning / 法医学杂志

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.

Virtual Autopsy Morphological Features of Drowning / 法医学杂志

OBJECTIVES@#To explore the application value of virtual autopsy to obtain key evidence information on drowned corpses and its application value of virtual autopsy in the diagnosis of drowning.@*METHODS@#In this study, 7 corpses were selected as the research objects. The image data of corpses were collected by computed tomography (CT) before conventional autopsy. The characteristics of corpses were observed through image reading, combined with virtual measurement indexes, and compared with 15 non-drowned corpses.@*RESULTS@#The postmortem CT of drowning showed the more fluid in respiratory tract than the non-drowning, and ground-glass opacities in the lung. The statistical volume of fluid in the sinus (maxillary sinus and sphenoid sinus) was (10.24±4.70) mL in drowning cases and (2.02±2.45) mL in non-drowning cases. The average CT value of fluid in the sinus, left atrial blood and gastric contents in drowning cases were (15.91±17.20), (52.57±9.24) and (10.33±12.81) HU, respectively, which were lower than those in non-drowning cases (P<0.05).@*CONCLUSIONS@#The comprehensive consideration of multiple characteristic image manifestations and the virtual measurement indexes are helpful to the forensic pathological diagnosis of drowning. Virtual autopsy can be used as an auxiliary method in the forensic diagnosis of drowning.

Application Progress of High-Throughput Sequencing Technology in Forensic Diatom Detection / 法医学杂志

Diatom detection is an important method for identifying drowning and throwing corpses after death and inferring the drowning sites in forensic examination of corpses in water. In recent years,high-throughput sequencing technology has achieved rapid development and has been widely used in research related to diatom taxonomic investigations. This paper reviews the research status and prospects of high-throughput sequencing technology and its application in forensic diatom detection.

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 Accumulated Degree Days for PMI Estimation / 法医学杂志

Among many factors that affect postmortem interval （PMI）, temperature is undoubtedly the most important factor, but simply considering temperature in estimation of PMI has limitations. Accumulated degree days （ADD） is an important indicator related to biological growth and development, which considers two major variables, environmental temperature and elapsed time. Therefore, the establishment of mathematical model of ADD and some evaluation indicators to estimate PMI, is obviously better than single temperature variable. This article briefly describes the research history of ADD, its application in PMI estimation, and the problems it faces, to provide reference for the further development of ADD to improve the accuracy of PMI estimation.

Application Prospects and Prospect of Metabolomics in the Identification of Sudden Cardiac Death / 法医学杂志

In cases of sudden death, the prevention of sudden cardiac death and the analysis of the cause of death after sudden cardiac death have always been a difficult problem. Therefore, clinical research and forensic pathological identification of sudden cardiac death are of great significance. In recent years, metabolomics has gradually developed into a popular field of life science research. The detection of "metabolic fingerprints" of biological fluids can provide an important basis for early diagnosis of diseases and the discovery of potential biomarkers. This article reviews the current research status of sudden cardiac death and the research on metabolomics of cardiovascular diseases that is closely related to sudden cardiac death and analyzes the application prospects of metabolomics in the identification of the cause of sudden cardiac death.

Forensic Progress on Death Following Carotid Sinus Inhibition / 法医学杂志

Death after carotid sinus trauma is usually attributed to death from inhibition, a type of sudden death. Currently, the number of incidents is scarce, and related studies are few. Therefore, how to determine the involvement of carotid sinus and determine the role of diseases in the cause of death has always been a difficult point in forensic investigation. This article sorts out the research literature on carotid sinus related death at home and abroad in recent years, systematically reviews the anatomic structure of the carotid sinus nerve, the clinical epidemiology of carotid sinus syndrome, and the research on the death mechanism of carotid sinus injury at home and abroad in recent years, in order to provide references for forensic pathology research and prosecution.

Forensic Analysis of 43 Medical Disputes Caused by Death after Cardiac Surgery / 法医学杂志

Objective To explore the causes and characteristics of medical disputes caused by death after cardiac surgery and to analyze the pathological changes after cardiac surgery and the key points of forensic anatomy, thus to provide pathological evidence for clinical diagnosis and treatment of cardiac surgery and judicial appraisal as well as reference for the prevention of medical disputes in such cases. Methods Forensic pathological cases of medical disputes caused by death after cardiac surgery which were accepted by the Center for Medicolegal Expertise of Sun Yat-Sen University from 2013 to 2018 were analyzed retrospectively from aspects such as causes of death, pathological diagnosis, surgery condition, medical misconduct, and so on. Results The causes of death after cardiac surgery of 43 patients were abnormal operation, low cardiac output syndrome, postoperative infection, postoperative thrombosis, and other diseases. Among the 43 cases, there were 18 cases without medical fault while 25 cases had medical fault. Conclusion The medical disputes caused by death after cardiac surgery are closely related to the operative technique and postoperative complications. The causes of medical faults include defects in diagnosis and treatment technique, as well as unfulfillment of duty of care.