Effects of Postmortem Hemolysis and Ultrafiltration on Creatinine Detection Results / 法医学杂志

OBJECTIVES@#To investigate the interference of postmortem hemolysis on the detection of creatinine and whether ultrafiltration can reduce the interference.@*METHODS@#A total of 33 non-hemolyzed whole blood samples from the left heart were collected. Hemolyzed samples with 4 hemoglobin mass concentration gradients H1-H4 were artificially prepared. Ultrafiltration was performed on each hemolyzed sample. Creatinine concentrations in non-hemolyzed serum (baseline serum), hemolyzed samples and ultrafiltrate were detected. Bias (B), Pearson correlation and receiver operator characteristic (ROC) of baseline creatinine concentration between before and after ultrafiltration were analyzed.@*RESULTS@#As the hemoglobin mass concentration increased, B of the hemolyzed samples in the H1-H4 groups gradually increased, the |B| was 2.41(0.82, 8.25)-51.31(41.79, 188.25), reaching a maximum of 589.06%, and there was no statistically significant between the creatinine concentration and the baseline creatinine concentration (P=0.472 7, r=0.129 5). After ultrafiltration of hemolyzed samples, the interference of creatinine concentration in ultrafiltrate was significantly reduced, the |B| was 5.32(2.26, 9.22)-21.74(20.06, 25.58), reaching a maximum of 32.14%, and there was a positive correlation with baseline creatinine concentration (P<0.05, r=0.918 2). In the hemolyzed samples of H3 and H4 groups, there were 7 false-positive samples and 1 false-negative sample; in the ultrafiltrate samples, there were no false-positive sample and 1 false-negative sample. ROC analysis results showed the hemolyzed samples were lack of diagnostic value (P=0.117 5).@*CONCLUSIONS@#The postmortem hemolysis significantly interferes creatinine detection results of blood samples, ultrafiltration can reduce hemolysis-induced interference in postmortem creatinine detection.

Research Progress of Exosomal microRNA in Cardiovascular Disease and Its Forensic Application Prospects / 法医学杂志

Exosomal microRNAs (miRNAs) are miRNAs that are mediated by exosomes to achieve cell-to-cell communication, and they are widespread in organisms. In recent years, the key role of the multiple biological functions of exosomal miRNAs in the occurrence and development of cardiovascular diseases has been confirmed by a large number of studies, which has become a hot spot in clinical and basic research. Sudden cardiac death caused by cardiovascular disease is one of the important contents in forensic medical identification. This article introduces the research progress of cardiovascular disease prediction, treatment and prognosis on exosomal miRNA. The prospects of the application in forensic medical identification are discussed.

Application of Postmortem Biochemistry Analysis in Forensic Medicine / 法医学杂志

In recent years, postmortem biochemistry analysis has gradually been applied to forensic practice, providing objective evidence for health conditions before death, disease pathophysiological processes and forensic diagnosis of postmortem interval and cause of death. It is of great significance to understand the change patterns of postmortem biochemical indicators and their applications in forensic medicine. This article reviews the research progress of postmortem biochemistry and its application in forensic medicine, it summarizes the existing problems of postmortem biochemistry analysis in forensic medicine of China and discusses the application prospect of postmortem biochemistry analysis in forensic medicine. This review is expected to provide references for forensic practitioners.

Stability of IgE in Postmortem Plasma and Hemolyzed Samples / 法医学杂志

Objective To investigate the stability of IgE in postmortem plasma and hemolyzed samples under different storage conditions and freezing-thawing. Methods Thirty nine cardiac blood samples were collected from non-frozen corpses with the postmortem interval of less than 48 hours, including 20 plasma samples and 19 hemolyzed samples taken from whole blood. The samples were stored at -20 ℃, 4 ℃ and 25 ℃ for 28 d and at -80 ℃ for 1 year to evaluate the stability of IgE under different storage conditions. Repeated freezing-thawing treatment was conducted for 5 times to explore the stability of IgE in postmortem plasma and hemolyzed samples. IgE concentration in plasma and hemolyzed samples was detected by electroluminescence before and after treatment. Results The degradation rates of IgE in plasma samples under the three storage conditions, -20 ℃, 4 ℃ and 25 ℃ were close. After 28 d, the mean value was about 15%, the degradation speed of IgE in hemolyzed samples was faster than that of plasma under the same condition （P<0.05） and the degradation rate was faster than other two conditions under 25 ℃ （P<0.05）. The differences in the concentration of plasma samples after freezing at -80 ℃ for 1 year and that before freezing had no statistical significance （ P>0.05）, while the concentration of hemolyzed samples was degraded after freezing at -80 ℃ for 1 year （P<0.05）. The differences between the detection results of plasma and hemolyzed samples after repeated freezing-thawing for 5 times and that before freezing-thawing showed no statistical significance （ P>0.05）. Conclusion IgE has good freezing-thawing stability in postmortem plasma and hemolyzed samples. Stability of IgE is better in postmortem plasma samples than hemolyzed samples, thus it is recommended to separate plasma from postmortem blood samples as soon as possible in forensic practice.

Application of Hollow Fiber Ultrafiltration Technology in the Detection of Total IgE of Hemolytic Blood after Death / 法医学杂志

Objective To investigate the treatment effect of hollow fiber ultrafiltration technology on hemolytic samples and the differences between IgE concentration and serum concentration before hemolysis in ultrafiltrate. Methods The 33 postmortem blood samples of non-frozen corpses within 72 hours after death were collected, 4 mL blood was taken from each case, among which 1 mL was centrifuged to get serum, and the remaining 3 mL blood was frozen-thawed 3-5 times to cause complete hemolysis. The 2 mL hemolytic samples were processed by hollow fiber ultrafiltration to obtain ultrafiltrate. The hemoglobin concentration in serum, complete hemolytic sample and ultrafiltrate was determined by Van-Zij solution-cyanated methemoglobin assay method, and the total IgE in serum and ultrafiltrate was determined by electrochemical luminescence method. Results The hemoglobin concentration in ultrafiltrate was significantly lower than that in complete hemolytic samples （P<0.05）. There was a good correlation between the total IgE detection values of ultrafiltrate and serum （r=0.984）. The difference between the serum and the value of IgE in ultrafiltrate after correction had no statistical significance, and the differences between the two in positive rates had no statistical significance （P>0.05）. Conclusion Ultrafiltration technology has a good treatment effect on complete hemolytic samples, and the correction value of ultrafiltrate detection is close to the serum level before hemolysis, and therefore, it can be applied to the detection of total IgE of frozen corpse hemolytic samples.

Research Progress and Forensic Identification of Alcoholic Cardiomyopathy / 法医学杂志

With the rapid development of the social economy in China, the incidence of diseases caused by excessive drinking is gradually increasing as well. Alcoholic cardiomyopathy refers to long-term high intake of ethanol, and has typical dilated cardiomyopathy characteristics, such as, hemodynamic changes, symptoms, signs, and morphological features. It is a kind of cardiomyopathy that excludes other causes of dilated cardiomyopathy. Due to the lack of specific pathological changes, the forensic pathological identification of alcoholic cardiomyopathy can only be based on the patient's medical history and by ruling out other causes of cardiomyopathy. This paper reviews the pathogenesis and forensic identification of alcoholic cardiomyopathy in order to provide reference for forensic pathologists and clinicians.

Statistical Analysis of the Heart and Lung Mass in Forensic Anatomical Cases and Its Forensic Significance / 法医学杂志

Objective To investigate the differences of heart mass and lung mass in forensic autopsy cases and to explore their application value in forensic identification. Methods The data from 1 614 autopsy cases accepted by center of Medico-legal Investigation of China Medical University between 2007 to 2016 were collected. The correlation of heart and lung mass with age, height, body weight, and body mass index （BMI）, as well as differences in different causes of death were analyzed by GraphPad Prism 6.0 software. Results The heart mass and lung mass of males were higher than those of females （P<0.05）. The heart mass of males and females was positively correlated with age, height, body weight and body mass index （BMI） （P<0.05）. The heart mass of patients dying from sudden cardiac death （SCD） was significantly higher than those dying from other causes of death. The lung mass of patients dying from drowning and delayed treatment was higher than those dying from other causes of death （P<0.05）. Conclusion In forensic practice, measurement of the heart mass and lung mass has certain significance for differential diagnosis and diagnosis of different causes of death.

Effect of Corpse Cryopreservation on Forensic Pathological Identification / 法医学杂志

Because cryopreservation can effectively slow down the putrefaction and prolong the preservation time of corpses, it has become the main way of corpse preservation in China. However, it may cause a certain degree of non-specific effects on the corpses and thus interfere with forensic pathological identification. This paper summarizes relevant problems reported in domestic and foreign literature reports and practical identification, and analyzes the effects of cryopreservation on corpses from aspects of anatomical findings, histomorphology, postmortem biochemistry, and postmortem imaging, therefore to provide Chinese forensic workers assistance on problems in their practice of forensic pathology.

Forensic Pathological Identification and Antidiastole of Commotio Cordis / 法医学杂志

Commotio cordis （CC） is the acute death caused by the cardiac rhythm disorder after a sudden blunt external force to the precordium of a healthy person without previous heart disease. As one type of violent heart damage, CC is rare with relatively small external force and sudden death, therefore causing disputes. This paper reviews the epidemiology, mechanisms and the key points in forensic identification of CC, discusses the identification and antidiastole of CC, myocardial contusion, sudden cardiac death and death from inhibition, and provides assistance to forensic pathologists to identify such causes of death.

The Changes of HIF-1α and VEGF-A in Myocardial Tissue of Rats with Arrhythmias / 法医学杂志

OBJECTIVES@#To observe the expression changes of hypoxia inducible factor-1α（HIF-1α） and vascular endothelial growth factor-A （VEGF-A） in rats with arrhythmias, and to explore the differences of the expression pattern in the two indicators of acute myocardial ischemia caused by arrhythmias and coronary insufficiency.@*METHODS@#The arrhythmia was induced by CaCl₂, and the expression changes of HIF-1α and VEGF-A were detected by immunohistochemistry, Western blotting and real-time PCR within 6 h after the arrhythmia in rats.@*RESULTS@#The expression of HIF-1α and VEGF-A showed diffuse in the myocardial tissue of rats died from arrhythmias. Both of them increased in the early arrhythmia, then decreased. Extensive myocardial ischemia happened at the beginning of arrhythmia occurrence and its range didn't expand with time.@*CONCLUSIONS@#The expressions of HIF-1α and VEGF-A in myocardium of the rats with arrhythmia can provide evidence for the differential diagnosis of acute myocardial ischemia caused by fatal arrhythmia and coronary insufficiency.

Expression of Brain Natriuretic Peptide in Myocardial Tissue of Sudden Cardiac Death and Non-sudden Cardiac Death / 法医学杂志

Objective To study the expression pattern of brain natriuretic peptide (BNP) in myocardial tissue from forensic routine cases and to explore its application value in the forensic determination of sudden cardiac death (SCD). Methods The data of 96 autopsy cases accepted by the center of Medico-legal Investigation of China Medical University between December 2008 to May 2014 were collected. There were 62 cases in SCD group cardiac and 34 cases in non-SCD group. The myocardial tissues were taken from left and right ventricular wall, respectively. The expressions of BNP protein and BNP mRNA in myocardial tissue were detected by HE staining, immunohistochemical staining, Western blot-ting and quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR), etc. Results The immunohistochemical staining of myocardial tissue showed diffusely positive staining in SCD group, and patchily or diffusely positive staining in non-SCD group with lighter degree. The result of Western blotting showed that the expression of BNP protein elevated in left ventricular wall of SCD group. The result of RT-qPCR showed a positive correlation between the BNP mRNA expressions in bilateral ven-tricular walls and the heart weight, bilateral lung weight, and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentration. There were large differences between the BNP mRNA concentra-tions in SCD group and non-SCD group, and the former was statistically higher (P<0.05). Conclusion The expressions of BNP protein and BNP mRNA in myocardial tissue are related to the causes of death. Combined with pathological changes, the expressions of BNP protein and BNP mRNA in myocar-dial tissue have certainly practical significance for the determination of SCD and the analysis of the death mechanism in the cases related to forensic pathology.

Changes of Serum IgE and Tryptase in Anaphylactic Shock Rats / 法医学杂志

OJECTIVE@#To explore the changes of serum IgE and tryptase caused by anaphylactic shock rats and discuss the relation to PMI and preservative environment of corpse and specimen.@*METHODS@#Rats were used for establishing anaphylactic shock models and randomly divided into room temperature group, refrigeration group, frozen group, manual hemolysis group, specimen preservation group. And the control group was also established. The blood samples were collected after rats were sacrificed. The degree of hemolysis was graded according to the color of the upper layer of the serum. The mass concentration of IgE and tryptase in each group was detected by ELISA.@*RESULTS@#The levels of serum IgE and tryptase in anaphylactic shock dead rats were higher than that of the control group. Room temperature and frozen made obviously differences on the levels of serum IgE and tryptase with various PMI. The levels of serum IgE and tryptase in refrigeration group showed relatively stable. The levels of serum tryptase and IgE were elevated with differently increasing hemolysis. The levels of serum IgE and tryptase showed no obvious changes during the specimen kept under different temperature conditions for 25 days.@*CONCLUSION@#Serum IgE and tryptase obviously increased in anaphylactic shock rats. However, the levels were influenced by PMI and environmental temperature, especially under the conditions of room temperature and frozen.

Biochemical indicators of anaphylactic shock and the application in forensic medicine / 法医学杂志

Fatal anaphylactic shock is common in forensic practice. However, it is difficult to diagnose for lacking specific pathological and morphologic changes in forensic autopsy. The application of some biochemical indicators is of great significance. This paper reviews the biological characteristics of some biochemical indicators and detection methods. The forensic application, problems and prospects of these indicators are also introduced in details. The stable biochemical indicators, IgE, tryptase and chymase, show great potential and advantages in the identification of fatal anaphylactic shock in forensic medicine.

Expression of BNP in rat myocardial tissue after acute cardiac dysfunction / 法医学杂志

OBJECTIVE@#To investigate the expression of brain natriuretic peptide (BNP) in rat myocardial tissue after acute cardiac dysfunction and to explore the role of BNP in diagnosis of cardiac dysfunction in forensic practice.@*METHODS@#Rat models of acute cardiac dysfunction were established. The expression of BNP protein and BNP mRNA in myocardial tissue after cardiac dysfunction were detected by immunohistochemistry, Western blotting and real-time RT-PCR.@*RESULTS@#The extent of positive staining of BNP increased over the time course during cardiac dysfunction. The expression of BNP showed mild positive in cardiomyocytes from 1 h to 2 h. From 4 h to 6 h, the expression was moderate positive. From 10 h to 12 h, the BNP showed a strongest positive expression. The expression of BNP presented a significant raise with the increasing time of cardiac dysfunction by Western blotting and real-time RT-PCR. The expression of BNP mRNA increased significantly 1 h after cardiac dysfunction.@*CONCLUSION@#Investigating the expression of BNP protein and BNP mRNA in myocardial tissue may provide a new approach to evaluate the cardiac function for forensic pathologists.

Early expression of hypoxia-inducible factor-1 alpha after acute myocardial ischemia in rats / 法医学杂志

OBJECTIVE@#To observe the changes of hypoxia-inducible factor-1 alpha (HIF-1alpha), the expression in the early stage (within 6 h) of acute myocardial ischemia and to explore the potential forensic application.@*METHODS@#SD rats were randomly divided into one control group, one sham operation group and five myocardial ischemia groups which received ligation of the left anterior descending (LAD) coronary artery. The five experiment groups divided into 15min, 30min, 1 h, 3 h and 6h after LAD ligation. The expression of HIF-1alpha was detected by immunohistochemistry, immunofluorescence and Western blotting, respectively.@*RESULTS@#Both the control group and sham operation group showed no expression of HIF-1alpha, whereas the expression of HIF-1alpha could be weakly detected beneath the endocardium at 15 min after LAD ligation. With the increase of myocardial ischemia process, the positive staining gradually extended from endocardium to epicardium, reached the peak at 3 h, and began to decrease gradually at 6h after LAD ligation but still maintained at a relatively high level. In addition, the expression of HIF-1alpha without a time-dependent way was also detected in full thickness of the right ventricle in occurrence of ventricular arrhythmia after LAD ligation.@*CONCLUSION@#HIF-1alpha may be regarded as a sensitive marker for sudden cardiac death induced by early acute myocardial ischemia, and may also be helpful for the diagnosis of fatal arrhythmia.

Mechanism of methamphetamine intoxication and its medical identification / 法医学杂志

Methamphetamine (MA) is a representative drug of amphetamine-type stimulants for central nervous system and has become one of the most dangerous drugs in the world recently. The present article reviews the pharmacological effects, distribution, metabolism, intoxication mechanism, the effects of MA on cardiovascular and central nervous systems of MA, and the current situation of forensic investigation on MA.