Research Progress of Metabolomics in Forensic Pathology / 法医学杂志

Metabolomics is an interdisciplinary subject that rose in the post-genomic era, which focuses on quantitative study of the response of living organisms to outside stimulation and pathophysiological changes, as well as multiple dynamic response of the level of in vivo metabolites caused by genetic mutation. It is extensively used in basic research of system biology, materia medica, clinical medicine, etc. In the forensic field, metabolomics mainly focuses on forensic toxicology, but with the generalization of certain techniques, it's foreseeable that metabolomics has a broad research prospect in forensic pathology. This article summarizes the major analysis techniques and methods of metabolomics, describes the research status of metabolomic techniques in the field of forensic pathology application research, including postmortem interval and death cause. Moreover, this article summarizes and discusses the potential applicable areas, in order to provide reference for relative research and application.

Application of Convolutional Neural Network in Identifying Different Levels of Isokinetic Exercise Efforts / 法医学杂志

Objective To develop a convolutional neural network （CNN） that can identify isokinetic knee exercises moment of force-time diagrams under different levels of efforts. Methods The 200 healthy young volunteers performed concentric isokinetic right knee flexion-extension reciprocating exercises with maximal effort as well as half the effort at angular velocities of 30°/s and 60°/s twice, respectively, with an interval of 45 min. The moment of force-time diagrams were collected. The 200 subjects were randomly divided into the training set （140 subjects） and the testing set （60 subjects）. The moment of force-time diagrams from subjects in the training set were used to train CNN model, and then the fully trained model was used to predict types of curves from the testing set. Random sampling of subjects along with subsequent development of models were performed 3 times. Results Under the circumstances of isokinetic knee exercises with maximal effort and half the effort, 2 400 moment of force-time diagrams were produced, respectively. Classification accuracy rates of the CNN models after the 3 trainings were 91.11%, 90.49% and 92.08%, respectively, and the average accuracy rate was 91.23%. Conclusion The CNN models developed in this study have a good effect on differentiating isokinetic moment of force-time diagrams of maximal effort exercises from those made with half the effort, which can contribute to identifying levels of efforts exerted by subjects during isokinetic knee exercises.

Difference Analysis Based on 16S rRNA Sequencing of Different Soil Bacterial Communities / 法医学杂志

Objective To study the structure and differences of bacterial communities in different soils, and to explore the effectiveness of 16S rRNA sequencing in identification of different soil. Methods Soil samples from 7 places in Shanghai were collected, then bacterial genomic DNA were extracted from them. The fragments of hypervariable region from 16S rRNA sequences were sequenced with high-throughput sequencing techniques. The results were quantified or visualized with bioinformatics software. The differences in diversity and abundance among the three kinds of bacterial communities in soil samples from grassland, forests and beaches were compared and analyzed. Results The statistical differences that existed among the alpha diversity indexes of bacterial communities in soil samples of grassland, forests and beaches had statistical significance. The relative abundance and diversity of bacterial communities in these three kinds of soil were significantly different. Grassland soil had higher Acidobacteria abundance, forest soil had higher Proteobacteria abundance, beach soil had higher Actinobacteria abundance. However, the differences in soil bacterial communities in artificial grasslands, natural grasslands and industrial district grasslands did not have statistical significance. Conclusion 16S rRNA sequencing can effectively distinguish different soils. This method may be able to provide clues for first crime scene inference in criminal cases.

Research Progress of CircRNA and Its Application Prospect in Forensic Medicine / 法医学杂志

Circular RNA(circRNA)is a type of noncoding RNA with tissue specificity and high stabil-ity, which forms a closed continuous loop and is abundantly expressed in tissue cells. According to re-cent research, the regulatory function of circRNA elucidating in the occurrence and development of dis-ease shows a potential for diagnosing clinical disease and revealing disease mechanism. This paper re-views the biological characteristics, analysis methods of circRNA and its research progress in clinical ap-plication as biomarker, and outlooks its application in the field of forensic medicine.

Risk factors of aplastic anemia: A Meta-analysis / 预防医学

Objective To comprehensively evaluate the risk factors of aplastic anemia, and provide scientific evidence for the primary prevention of aplastic anemia. Methods The published Papers were searched by"aplastic anemia" "case control study" and"risk factors" as key words collected from Chinese National Knowledge Infrastructure, Chinese VIP journal database, PubMed, Cochrane library and Clinical Trial and other databases, ranged from the creation date of each database to September 2017 .A meta-analysis of studies on risk factors was performed to calculate the pooled odd ratios (ORs) with 95％ confidence intervals (CIs) with Software Stata 14.0. Results The database search resulted in the identification of 1, 094 articles. After screening, 22 case-control studies were included in the study with 16 factors. Ten risk factors were showed statistically significant differences, including paint exposure (OR=3.82, 95％ CI: 1.68-8.66), chloramphenicol (OR=3.21, 95％ CI: 1.98-5.20), benzene exposure (OR=2.94, 95％ CI: 2.11-4.11), glue exposure (OR=2.56, 95％CI: 1.28-5.12), history of hepatitis (OR=2.54, 95％ CI: 1.94-3.34) , hair dye exposure (OR=2.37, 95％ CI: 1.08-5.22) , pesticides exposure (OR=1.98, 95％ CI: 1.60-2.45), β-lactam (OR=1.77, 95％ CI: 1.03-3.06), sulfonamides (OR=1.64, 95％ CI:1.03-2.61) and fuel/oil exposure (OR=1.53, 95％ CI: 1.25-1.87) , and high economic income (OR=0.52, 95％ CI:0.43-0.63) is the protective factor. Conclusion The meta-analysis of case-control studies suggests that the risk factors of aplastic anemia mainly including four aspects: drug use, past history, socioeconomic status and occupational or environmental exposure to chemical toxic substances.

Forensic Analysis of 24 Cases of Long-term Antipsychotics Use-Induced Sudden Unexpected Deaths / 法医学杂志

Objective To analyze the forensic characteristics of 24 psychiatric patients who died of long-term use of psychotropic drugs.Methods Cases of sudden death of psychiatric patients from2011 to 2016 were collected.The forensic characteristics of these sudden deaths were retrospectively analyzed by systematic investigation plus results of autopsy and toxics (drugs).Results Among the 24psychiatric patients who died of long-term use of psychotropic substances, the ratio of male to female was 1.7∶1, and the average age was (59.0±8.8) years.Fifteen patients had clear disease durations (14.4±8.2) years, and other the nine were known to have disease durations of over 3 years.The death time of 62.5％of patients was the daytime in working days, and 91.7％of the patients died at home.Most patients complained different degrees of physical discomfort before death.Patients with schizophrenia (20 cases) were the most common, followed by depression (4 cases).All patients had the history of taking psychotropic drugs, with clozapine and chlorpromazine being the mostly detected ones.The causes of death were mainly circulatory diseases (15 cases), with the most common being myocarditis (11 cases) followed by pneumonia (4 cases).Conclusion Critical attention should be paid to the risk of antipsychotics-induced sudden unexpected deaths for psychiatric patients, particularly for those with schizophrenia.

Brief discussion on the proof standard of traditional evidence of forensic pathology in murder cases / 复旦学报（医学版）

Objective In the legal proceedings of murder cases,we often encounter the problem of proof standard in traditional forensic pathology in deep research,which is lack of systemic discussion in domestic academic field.This paper aimed to discuss this problem.Methods We compared the relevant characteristics of different legal systems on the standard of proof system,analyzed the elements of the forensic pathology evidence related to murder cases,and discussed the problem with the author's judicial practice experience.Results We believe that the cause of death,death time,injury and injury tools are the three most important forensic pathology evidences in the murder of the standard system as the "three pillars".Conclusions Division of standards in traditional forensic pathology evidence in the murder is of great significance to raise the sense of evidence of forensic medicine,and if it exists major flaws in the evidence of forensic pathology,the evidence can be corrected or the proceedings can be terminated at the very beginning of the litigation phase,which is of great value to the savings of judicial resources.

Application of the Peak Area Ratio of STR Loci to Amelogenin Locus in the Estimation of DNA Degradation / 法医学杂志

OBJECTIVE@#To explore the change rules of peak area ratio of STR loci to Amelogenin (AMEL) locus (STR/AMEL), a sex-determining gene in DNA degradation, and to evaluate the application of STR/AMEL value in the estimation of DNA degradation degree.@*METHODS@#DNA was extracted from iliopsoas, and the variations of STR/AMEL value (Penta E/AMEL, Penta D/AMEL, FGA/AMEL) were analyzed after the artificial degradation was made by DNase I, and the changes of these three ratios of the iliopsoas naturally degraded in an outdoor environment were also analyzed. The regression curves were analyzed using the periods of DNA degradation and outside the body as the independent variable (x) and the STR/AMEL value as the dependent variable (y) and three curve equations under two conditions were established.@*RESULTS@#Both under the conditions of artificial and natural degradation, STR/AMEL value had a negative relationship with the degradation time. The relationship between STR/AMEL and degradation time can be well simulated by the cubic function. R2 was over 0.99 under controlled degradation condition and over 0.86 under natural degradation condition.@*CONCLUSION@#The STR/AMEL value (Penta E/AMEL, Penta D/AMEL, FGA/AMEL) is negatively related with the DNA degradation degree, which follows mathematical regression models strictly, and it might be applied to evaluate the DNA degradation degree.

Analysis of 59 Anaphylactic Death Cases / 法医学杂志

OBJECTIVE@#To analyze the cases of anaphylactic death cases and explore the standards of judicial expertise of anaphylactic death for providing evidence for judicial expertise.@*METHODS@#Fifty-nine cases death due to allergic reaction in Shanghai were collected. And details of medical history, clinical manifestation of anaphylactic reaction and postmortem examination findings were reviewed for all cases.@*RESULTS@#In the 59 cases, there were 58 cases died from drug allergy, including 77.6% of them were antibiotics. The rates of treating in standard hospital and illegal clinic were 37.3% and 61.0%, respectively. The allergic symptoms were dyspnea and facial cyanosis. The time from contacting allergens to death ranged from 1 min to 3 d. The concentration of total serum IgE ranged from 50 to 576.92 IU/mL. The results of clinical manifestation and pathological anatomy had obviously changes.@*CONCLUSION@#Based on the exclusion of all other cause of death and synthetically analysis of details of cases, medical history, clinical manifestation and anatomy, the conclusion of anaphylactic death can reached. The details of cases including clinical history, exposure to allergens, and clinical manifestation play an important role in diagnosis of anaphylactic death.

Expression of EIIIA+ fibronectin in incised wound of rat's skin / 法医学杂志

OBJECTIVE@#To explore the relationship between the expression of EIIIA+ fibronectin in incised wound of rat's skin and injury time.@*METHODS@#The wounding model was established by cutting the dorsal skin of 48 adult SD rats. The rats were sacrificed at the pre-set injury time as immediately, 0.5 h, 1 h, 2 h, 3 h, 4 h, 6 h, and 8 h. The skin samples were taken at the margin of wound. The expression of the EIIIA? fibronectin was detected by immunohistochemistry and Western blotting and the relationship be- tween its expression and injury time was observed. Results The expression of EIIIA+ fibronectin was not observed immediately. The basal cell of skin began to show positive expression 0.5 h after injury. With the extension of injury time, positive staining became stronger. The value of relative optical density was gradually increased with prolonged injury time by the Western blotting analysis.@*CONCLUSION@#The expression of EIIIA+ fibronectin could be used for estimation of injury time in the early stage of skin injury.

1H-MRS study on the metabolites of first dorsal interossei / 法医学杂志

OBJECTIVE@#To estimate the application of prognosis evaluation of ulnar nerve injury by 1H-magnetic resonance spectroscopy (1H-MRS).@*METHODS@#The metabolites of first dorsal interossei (FDI) of two hands from 12 healthy volunteers and 1 volunteer with complete ulnar nerve injury were detected by 1H-MRS and the data were statistically analyzed.@*RESULTS@#For the FDI of healthy adults, the female peaks area of extra-myocellular lipids (EMCL) was higher than the male (P < 0.05); There was no significant difference in Cho, Cr and intra-myocellular lipids (IMCL) between male and female (P > 0.05); There was no significant difference in all the peaks area between the left and right hand (P > 0.05). The EMCL peak of the injury side was higher than that of the healthy side, and the area of FDI was reduced in the volunteer with ulnar nerve injury.@*CONCLUSION@#Noninvasive and quantitative detection of 1H-MRS may be valuable for prognosis evaluation of peripheral nerve injury.

Myocardial expression of Spry1 and MAPK proteins of viral myocarditis / 法医学杂志

OBJECTIVE@#To discuss the myocardial expression of Spry1 and MAPK proteins of viral myocarditis (VMC), to reveal its mechanism of sudden death, and to provide guides for forensic identification of sudden cardiac death.@*METHODS@#Thirty Balb/c male mice were randomly divided into VMC group and control group, inoculated intraperitoneally with Coxsackievirus B3 and Eagel's solution, respectively. After the mice were sacrificed, the cardiac tissues of the mice were taken to proceed regular pathological examination. The changes of Spry1 protein, Spry1 mRNA and MAPK protein were detected by immunohistochemistry, Western blotting and real-time PCR.@*RESULTS@#Under light microscope, the pathologic changes included myocardial interstitial edema, inflammatory cells infiltration, myocardial necrosis, and focal and patchy necrosis of myocardial fiber in VMC group. The expression of Spry1 protein in VMC group was lower than that in control group (P < 0.05). There was slightly decreased expression of Spry1 of the mRNA level in VMC group (P > 0.05). But the MAPK protein expression in VMC group was higher than that in control group (P < 0.05).@*CONCLUSION@#The pathway of MAPK/ERK involving Spry1 protein accelerates the expression of collagen, which may contribute to arrhythmia, heart failure and even sudden cardiac death.

Evaluation on stability of internal controls in human cardiac muscle by real-time RT-PCR during early postmortem interval / 法医学杂志

OBJECTIVE@#To explore the stability of internal controls in human cardiac muscle by real-time RT-PCR during early postmortem interval (PMI) in order to find the most stable marker.@*METHODS@#Ten individuals with similar environmental conditions (the average store temperature: 25 degrees C) and different PMI ranging from 4.3 to 22.3 h were selected. Total RNA was extracted from each sample and six commonly internal controls were used including beta-actin, GAPDH, B2M, U6, 18S rRNA and HSA-miR-1, and the expression was detected in cardiac muscle by real-time RT-PCR. The expression stability of internal controls was evaluated using genormPLUS software during early PMI. The internal control with the most stability was selected. The relationship between the most stable marker and its expression level affected by some other parameters such as age, gender and cause of death was also analyzed.@*RESULTS@#The U6 showed the most stable expression during early PMI in cardiac muscle, and its expression level was not affected by those parameters including age, gender and cause of death (P > 0.05).@*CONCLUSION@#U6 may be a valuable internal control for the study of relationship between PMI determination and degradation of nucleic acid in human cardiac muscle by real-time RT-PCR.

Analysis of death cases involved in TASER in the State of Maryland / 法医学杂志

OBJECTIVE@#To evaluate the features of autopsy cases involved in electronic weapon (TASER) in the State of Maryland, and to discuss the appraisable points.@*METHODS@#Thirteen autopsy cases involving TASER were collected from 2004 to 2011 in the Office of the Chief Medical Examiner, State of Maryland. All the cases include detailed scene investigations, complete autopsy, toxicological analysis and histopathological examination. Statistical analysis were conducted including general information of victim, type of TASER, type of contact, toxicological results, manner and cause of death.@*RESULTS@#Majority of victims were male with an acute onset of agitated and delusional behavior. Drugs were often involved. Deaths were attributed to multiple factors.@*CONCLUSION@#Most of cases involved in TASER resulted from multiple fatal factors. Further researches are needed for the principal mechanism. Thorough scene investigation and complete autopsy examination play crucial role in evaluation of such cases.

Estimation of early postmortem interval using beta-actin mRNA in rat's brain, heart and kidney / 法医学杂志

OBJECTIVE@#To explore the relationship between beta-actin mRNA degradation in SD rat's brain, heart and kidney and early postmortem interval (PMI) in order to find new markers for estimating early PMI.@*METHODS@#Rats were sacrificed and kept in the place at a temperature of 20 degrees C. The total RNA were extracted from the brain, heart and kidney at different PMI points. Real time RT-PCR was applied to determine beta-actin mRNA levels in total RNA and the results were given in the form of Ct values. Linear relationships between PMI and Ct values were obtained and the functions of linear regression were established.@*RESULTS@#The great decrease of beta-actin mRNA level were observed in the three organs. The degradation rate was obviously higher in 24 hours after death in the heart and kidney. However, there were no significant changes in the brain. The changes of Ct values and PMI showed a good linear relationship.@*CONCLUSION@#beta-actin mRNA in rat's brain, heart and kidney degrades obviously after death and can be used for estimating early PMI by its degradation rules.

Estimation of postmortem interval using microRNA and 18S rRNA degradation in rat cardiac muscle / 法医学杂志

OBJECTIVE@#To explore the relationship between the time-dependent level changes of microRNA and 18S rRNA and the different postmortem interval (PMI) in rat cardiac muscle.@*METHODS@#SD rats were sacrificed by cervical dislocation and placed at ambient temperature 25 degrees C with a humidity of 50%. Total RNA was extracted from the rat cardiac muscle at different time points after death. The levels of miR-1-2 and 18S rRNA were examined using real-time PCR in rat cardiac muscle. The results were expressed by cycle threshold (Ct) value to explore relationship between PMI and Ct value, and the regression functions were established to estimate PMI.@*RESULTS@#The miR-1-2 level in rat myocardial tissue showed no significant changes within 120 h after death, and then began to decline. The 18S rRNA level increased gradually within 96 h after death, and then declined slowly. The nonlinear relationships were established between Ct value (18S rRNA), deltaCt value (difference between 18S rRNA and miR-1-2) and PMI. The R2 of conics fitting were 0.9487 and 0.8072, respectively.@*CONCLUSION@#Ct value of 18S rRNA and deltaCt value present a good correlation with PMI, and can be markers for estimating early PMI.

Sudden infant death syndrome (SIDS) and its forensic investigation / 法医学杂志

During the past two decades tremendous efforts have been made by the medical community, especially in the fields of forensic medicine and pediatrics, to better understand the etiology, epidemiology and pathophysiology of SIDS. There have been many SIDS reports from developed countries, but few from developing Asian countries. Despite a recent significant decrease in the incidence of SIDS in many developed countries, SIDS continues to be the most common cause of post-neonatal infant death in these countries. This article analyzes the SIDS data (1990-2006) from the Office of the Chief Medical Examiner for the State of Maryland, USA, along with review of the literature with regard to the history, epidemiological and pathophysiological characteristics of SIDS, as well as the recent advances in SIDS research. The changing trends in the diagnosis of SIDS and current challenges to its forensic investigation are also discussed.

Characteristics and mechanism of boat propeller injuries / 法医学杂志

OBJECTIVE@#To summarize the characteristics and investigate the mechanisms of boat propeller injuries so as to explore the identification methods between boat propeller injuries and corpse dismemberment.@*METHODS@#More than 100 autopsy cases of boat propeller injuries were collected in a period between 1994 and 2005 in Huzhou district, Zhejiang province. The characteristics of injuries caused by propeller, including abrasion, wound, fracture and severed wound, and the characteristics of clothing, were retrospectively studied and summarized. The severed cross wound section of boat propeller injuries was compared with that caused by corpse dismemberment.@*RESULTS@#The boat propeller injuries were resulted from high-speed propellers with enormous splitting power and mechanical cutting, while corpse dismemberment were resulted from cutting and dismembering the body with sharp instruments. Due to the different mechanisms, the different strength of force and recoil force, the severed wound cross section had different characteristics.@*CONCLUSION@#Wounds caused by boat propeller injuries have their unique characteristics, distinguished from wounds of dismembered corpse.

Anatomy study of MGA in Chinese and its effect on legal expertise / 法医学杂志

OBJECTIVE@#This study aimed to clarify the morphology of the Martin-Gruber anastomosis (MGA) in Chinese.@*METHODS@#One hundred and five Chinese upper limbs (36 males and 20 femalese) were dissected to find the connections between medial nerve and ulnar nerve. The MGA was classified as previously described by Lee.@*RESULTS@#MGA was found in 24 cases (22.9%), in 11 of the 36 male and 5 of the 20 female. There was no obvious difference in the frequency of MGA in both upper limbs. Most MGA ulnar position was located at the medial and distal segment of the forearm.@*CONCLUSION@#MGA anatomy could play important role in forensic diagnosis of ulnar nerve injury in Chinese population.

Expression of EDA-fibronectin in injured human skin fibroblast and its potential application in estimation of wound healing / 法医学杂志

OBJECTIVE@#[corrected] To study the expression of EDA-FN variant in injured human skin fibroblast and its relation to wound healing.@*METHODS@#Human skin fibroblast cells were separated from human skin and cultured and monoclonal antibody to fibronectin [IST-9] was applied to amplify target segments.@*RESULTS@#Trace amount of EDA-FN was detected in the culture cells. The expression was increased within 8 hours after the injury.@*CONCLUSIONS@#The expression of EDA-FN would be an ideal marker for estimation of wound healing