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.

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.

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.

Application of Immunohistochemistry and Special Staining Technique in Forensic Traumatic Pathology Identification / 法医学杂志

In forensic traumatic pathology practice, immunohistochemistry and special staining technique play an important role in wound age estimation and complications of traumatic complication identification. They even play an important role in the identification of special cases, such as snakebites and insulin killings. This article reviews the application and value of immunohistochemistry and special staining techniques in forensic traumatic pathology based on the cases of forensic practice reported in literature.

Prospects of Application of Microbial Biofilm to Estimate PMI of Corpses in Water / 法医学杂志

In forensic pathology, the estimation of postmortem interval （PMI） has always been a difficult issue, and there is still lack of effective methods to estimate PMI of corpses in water. Microbial biofilm refers to the microbial population attached to non-biological or biological surfaces by microorganisms during microbial growth, that has a three-dimensional structure, surrounded by extracellular polymers and matrix networks created by itself. A series of community succession phenomena of microorganisms occur during the occurrence and development of microbial population. The microbial community and its succession process of this kind of biofilm attached to the surface of a corpse in water may become a new basis for estimation of the PMI of corpses in water. This review elucidates on the concept, classification, research methods, and influencing factors of biofilm and analyzes its application prospects in PMI estimation of corpses in water, which would provide new ideas for the researches in this field.

Analysis of 4 Cases of Electrocution due to Direct Current Electronic Hunter / 法医学杂志

Objective To summarize the characteristics of cases of electrocution due to direct current （DC） electronic hunter, and to provide references for forensic identification. Methods Four cases of electrocution due to DC electronic hunter were collected. Statistical analysis was carried out from the perspective of the scene and electric marks distribution, damage characteristics and histopathological changes. Results All the 4 cases of electrocution were accidental events. There were multiple electric marks, most of which were located in the lower limbs with serious damage. Some strip type electric marks were visible. Conclusion The distribution, morphological characteristics and severity of the electric marks caused by DC electronic hunter are different from those of the ordinary low-voltage alternating current damage. It is alerting that there would be actions of destroying the scene and abandoning the corpse in such cases.

Development of Integrated Device of Trace Bloodstains Imaging and Age Analysis / 法医学杂志

Objective To develop a device of trace bloodstains imaging and age analysis, so as to provide a non-destructive, simple and objective method for age estimation of bloodstains at the crime scene. Methods Based on the principle of digital imaging and color pattern analysis, the mobile terminal of the device was used to collect images of bloodstains of different ages. The time-dependent pattern of 6 parameters （R, G, B, C, Y, M） reflecting the changes of color of images of different ages was obtained by computer image analysis. A multiparameter comprehensive inference equation of bloodstains age was established and embedded into the device software to realize the intelligent inference of the bloodstains age. Then the capability and reliability of the device was verified. Results This integrated device of bloodstains imaging and age analysis could quickly collect bloodstains at the crime scene and automatically analyze and infer the age of bloodstains combined with related intelligence software. In the blind test, the detection accuracy of this device was 95% in both natural light airtight group and dark airtight group, and 80% in the natural light ventilation group. Conclusion The integrated device of trace bloodstains imaging and age analysis can be used in a simple manner, which provides a new objective method for bloodstains age estimation.

Diatom Detection Using Enzyme Combined with Strong Acid Digestion Method / 法医学杂志

OBJECTIVES@#To detect diatom in the organs of drowners by enzyme combined with strong acid digestion method, and evaluate its application value.@*METHODS@#A total of 40 cases which have been identified as drowning in local region were collected. Samples of the lung, liver, kidney, and the water of the scene were also gathered from each case. Strong acid digestion method, enzyme combined with strong acid digestion method, and enzymic digestion method were respectively performed to detect the diatom in the samples. The comparative analysis was made on digestion time, digestive power and detection rate of diatom, etc.@*RESULTS@#Enzyme combined with strong acid digestion method was significantly better than enzymic digestion method on digestion time and digestive power; enzyme combined with strong acid digestion method were obviously superior to strong acid digestion method on the detection rate of diatom.@*CONCLUSIONS@#Enzyme combined with strong acid digestion method combines the advantages of strong acid digestion method and enzymic digestion method. It has the characters of operation safety with little pollution to environment, which is worthy of further popularization and practice.

Relationship between PMI and ATR-FTIR Spectral Changes in Swine Costal Cartilages and Ribs / 法医学杂志

OBJECTIVE@#To analyze postmortem chemical changes in Landrace costal cartilages and ribs using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, and to provide a novel technique for estimation of postmortem interval (PMI).@*METHODS@#The swines were sacrificed by hemorrhage and their costal cartilages and ribs were kept in 20 degrees C. The chemical analysis of the costal cartilages and ribs were performed using ATR-FTIR every 72 h. The correlation between the certain spectral parameters and PMI was also analyzed. The time-dependent changes of costal cartilages were more significant than ribs.@*RESULTS@#There were no obvious changes for the main absorbance bands position, and some absorbance band ratios showed time-dependent changes and significant correlations with the PMI.@*CONCLUSION@#ATR-FTIR has the ability to analyze postmortem chemical changes of the swine costal cartilages and ribs, and it can be a new method to estimate PMI based on spectroscopy.

Research Advances in Postmortem Chemistry / 法医学杂志

Postmortem chemistry is becoming more and more essential in routine forensic pathology and has made considerable progress over the past years. Biochemical analyses of vitreous humor, blood, urine and cerebrospinal fluid may provide important information in determining the cause of death or in elucidating forensic issues. Postmortem chemistry may be essential for the determination of cause of death when morphological methods (diabetes mellitus, alcoholic ketoacidosis and electrolytic disorders) cannot detect the pathophysiological changes involved in the death process. It can also provide many information in other forensic situations, including myocardial ischemia, sepsis, inflammation, infection, anaphylaxis and hormonal disturbances. The most recent relevant research advances on glucose metabolism, liver function, cardiac function, renal function, sepsis, inflammation, infection, anaphylaxis and hormonal aspect are hereby reviewed.

A retrospective analysis of estimating postmortem interval in 256 murder cases / 法医学杂志

OBJECTIVE@#To discuss the method of reducing error in estimating postmortem interval (PMI).@*METHODS@#Two hundred and fifty-six solved murder cases from 2003 January to 2013 January in Changzhou and Nanjing City were collected, The PMI of all cases was estimated by traditional method and then compared with the real PMI obtained after the cases were solved. The cases were grouped according to the PMI, the accuracy was calculated, and the reasons of suboptimal PMI were analyzed.@*RESULTS@#The accuracies of early PMI (less than 12h and 13-24 h) were 90% and 89%, respectively; while the accuracies of late PMI (1-7 d, 1-2 weeks, 3-4 weeks, 1-6 months, 7-12 months and 1-5 years) decreased over time, being 79%, 76%, 83%, 79%, 60% and 50%, respectively. The common reasons of estimating error included improper inference methods, water submerged body, extreme temperature, lack of objective evidence, intentionally abandoned body, and changed or destroyed scene, etc.@*CONCLUSION@#The multiple index data can reduce the error in estimating PMI.

Apoptosis in adult mouse brain after chronic poisoning of ketamine / 法医学杂志

OBJECTIVE@#To study the effect of chronic poisoning of ketamine on brain cell apoptosis in adult mouse under different duration and doses.@*METHODS@#The mouse model of chronic poisoning of ketamine was established on adult mouse by tail vein injection of ketamine twice every week with different doses (4, 10, 20 and 30 mg/kg). The mice were sacrificed after continuous injection of ketamine of 1, 2, 4, 8 and 12 weeks. The qualitative assessment of apoptosis was made by transmission electron microscope and the quantitative assessment was made by Caspase-3 immumofluorescence staining method and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) to estimate the time point of apoptosis. All the experimental results were statistically analyzed.@*RESULTS@#The neuron apoptosis was observed in hippocampus and corpus striatum by transmission electron microscope one week after administration, and continued for eight weeks. High level of Caspase-3 expression was observed one week after administration, but with a low level expression after 4 weeks. The number of TUNEL positive cells obviously increased one week after administration and maintained in a high number at 4 weeks.@*CONCLUSION@#Ketamine by tail vein injection could induce neuron apoptosis in adult mouse.

Correlation between the changes of oxidation reduction potential values and postmortem interval of heart blood in rabbits after death / 法医学杂志

OBJECTIVE@#To investigate correlation between the changes of oxidation reduction potential (ORP) values of heart blood in rabbits after death and postmortem interval (PMI) at different temperatures.@*METHODS@#Forty-eight rabbits were randomly divided into 6 groups and sacrificed by air embolism. Blood samples were taken from the right ventricle of each rabbit and stored at different temperatures of 10, 15, 20, 25, 30 and 35 degrees C, respectively. Every 4 hours from 0 h to 132 h postmortem, the ORP values of the blood samples were measured at different intervals by PB-21 electrochemical analyzer. The curvilinear regression equation was established by SPSS 17.0 software. The surface equation and 3D surface diagram were established by MATLAB 7.10.0 software.@*RESULTS@#The ORP values at different temperatures of heart blood in rabbits were highly correlated with the PMI. The ORP values rised obviously when the temperature was high and rised slowly when the temperature was low. The surface equation and 3D surface diagram were obtained.@*CONCLUSION@#The surface equation and 3D surface diagram of ORP values and PMI may be used for PMI estimation at different temperatures.

Progress in myofibroblast and its application in forensic medicine / 法医学杂志

The myofibroblasts have dual characteristics of smooth muscle cells and fibroblasts. In repairing tissular wound, myofibroblasts are involved in fibrogenesis and remodeling the extracellular matrix of the fibrotic cascades reaction. The review describes the morphological characteristics and biological behaviors of myofibroblasts and the application of skin wound age determination, which may provide reference for research in forensic medicine.

Applying multiple displacement amplification to DNA typing in the pathological section / 法医学杂志

OBJECTIVE@#To investigate the feasibility of applying multiple displacement amplification (MDA) to DNA typing in forensic pathological section.@*METHODS@#Ninety-eight pieces of pathological sections were prepared in terms of 3 factors as the period of preservation, tissue types and death ages, and randomized into groups by Latin square by double 7-order design. Silicon bead method was used to extract the DNA template. Compared with the PCR amplification performed directly by AmpFlSTR Identifiler kit in the control group, MDA was performed before amplification in the experimental group. Based on the samples from fresh autopsies as the standard genotypes, the number of detection and the detection rate were analyzed and compared between the experimental group and the control group.@*RESULTS@#Between the control group and the experimental group, there was significantly statistical difference regarding the rate of DNA typing in each period of the tissue sections preserved (P<0.01). The detection rate of the 16 loci in the experimental group was more than 95% when the period of the tissue sections were preserved within 360d. There was significant difference in different tissue types (P<0.01). But there was no significant difference in different death ages (P>0.01).@*CONCLUSION@#MDA is efficacious in DNA typing of forensic pathological sections, for it can improve the DNA template quantification through abating the inhibiting factor's concentration of PCR and reducing the rate of allele drop out (ADO). However, the period of the sections preserved and tissue types would affect the results of genotyping by MDA.

The impact of gender, age and tissues in vitro on estimating postmortem interval by FTIR spectroscopy / 法医学杂志

To investigate the influence of such individual factors as gender, age and tissues in vitro to the postmortem interval (PMI) by the Fourier transform infrared (FTIR) spectrometer in animal experiments. SD rats were classified into male and female groups, different age groups (21-day, 42-day and 63-day group), and tissues in vitro and in vivo groups. The rats were sacrificed by cervical dislocation, whose bodies were kept in a controlled environmental chamber set at (20+/-2) degrees C and 50% humidity. The liver, kidney, spleen, myocardium, brain, lung and skeletal muscle tissues were collected for measurement from time zero to 48 h postmortem. With the change of PMI, no obvious changes were found in the main FTIR absorbance peaks and their ratios at different time points. All the experimental groups showed no significant changes when compared with the controls. The gender, age and tissues in vitro were not found to be contributing factors in the estimation of PMI via FTIR spectroscopy.

A preliminary molecular study on protein profile of vital organs: A new direction for post mortem interval determination.

Estimation of the postmortem interval (PMI) is one of the most important tasks in Forensic Medicine. Six autopsy organ tissues such as brain, lungs, heart, liver, pancreas and kidney were taken at the time of forensic autopsy. All the proteins present in the tissues were extracted and the protein profile was analyzed on the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) starting from 0 day to 10th day after death. The protein profiles showed a consistent degradation pattern which was consistent and reproducible in all the samples with respect to the time interval. In conclusion, the protein profile of the vital body organs appears to be a useful method for estimating the post mortem interval up to 10th day. Advantage of this approach over others is that it can detect the post mortem interval over a long interval (0 - 10 days) with an easily detectable pattern of protein profile.

Sudden death due to arrhythmogenic right ventricular dysplasia: A medico-legal case report.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is characterized by progressive fibrofatty replacement of the myocardium that predisposes to ventricular tachycardia and sudden death in young individuals and athletes. The prevalence of ARVD/C is estimated as 1:1000 to 1:1250 in the general population. Although it is a relatively uncommon cause of sudden cardiac death, it accounts for up to one fifth of sudden cardiac death in people less than 35 years of age. Clinical presentation of ARVD/C usually consists of arrhythmias of right ventricular origin that include premature ventricular beats, sustained ventricular tachycardia and ventricular fibrillation that can lead to sudden death. The authors present a case of a 26 year old young male, carpenter by occupation, previously healthy, with sudden death. The internal and external postmortem findings were normal except for mild right ventricular hypertrophy. But histo-pathological examination of heart tissues revealed replacement of myocardial tissue with mature fibrofatty tissue. The following medico-legal autopsy case is being reported for its rarity and the importance of histopathology to find out the cause of death.

Exhumation: A 10-year retrospective study.

Exhumation is done for number of reason and includes establishment of identity, to know cause and manner of death, belated suspicion of an unnatural death or for medical insurance problems. It is infrequently done in India and due to cultural practice of cremation by burning to ashes the data are lacking. Compared with conventional autopsy done immediately after death, exhumation poses many problems. The present study was aimed to collect data regarding exhumation, to collect morphological findings in comparison with maximum postmortem interval and to analyze them in an attempt to formulate “catalogue of expectation” to supplement the published literature. Total 24 forensic exhumations performed at three centers of this region from 1999 to 2008 were evaluated retrospectively. Total 24 cases were analyzed and amongst them 12 were men and 12 were women and their age ranged from 3 years to 75 years (mean age 26.95). In the present series, the cause of death at exhumation could be clearly determined in 16 cases (66.6%). Amongst others, the burial practice and postmortem interval are major determining factors for possible outcome at exhumation.