CiteSpace-Based Visualization Analysis of Forensic Research in China from 2010 to 2019.

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.

Fatal extensive bone cement embolism: histological findings confirmed by Fourier transform infrared spectroscopy.

We herein report the first case of fatal extensive bone cement embolism appearing in pulmonary arterioles following surgical vertebral screw augmentation, which histological evidence of bone cement emboli was confirmed by Fourier transform infrared spectroscopy. A 47-year-old woman has accepted multilevel spine fusion and pedicle screw augmentation with totally 4 ml bone cement infusion. She suddenly developed low blood pressure, dyspnoea, and unconsciousness approximately 1 h post anaesthetic recovery, and then she was dead. It was shown both lungs were edematous in autopsy, and bluish emboli were appeared in extensive pulmonary arterioles in H&E stained sections. Negative information was shown in Molybdenum target X-ray imaging, but the emboli were confirmed to be PMMA bone cement by Fourier transform infrared spectroscopy. The present case indicated it might be effective to confirm the dubious trace component in histology by FTIR.

Changes in ATP levels in rabbit blood and its application for estimation of the postmortem interval.

Relationship between ATP changes of rabbit blood and postmortem interval (PMI) was studied. Twenty-four healthy rabbits were sacrificed and randomly divided into 3 groups with 8 rabbits of each group. The bodies of three groups were placed in calorstat at temperature of 15°C, 25°C and 35°C, respectively. The blood from the right ventricle was sampled through indwelling needle each 4 h until 72 h after death. ATP levels in the blood samples were measured by using ATP fluorescence rapid detection technique at different PMIs. Blood ATP levels slightly increased in the early stage after death and then constantly declined at all temperatures (15°C, 25°C, and 35°C). Cubic polynomial regression equations with log[ATP] as dependent variable (y) and PMI as independent variable (x) at different temperatures and the optimal time period were established as followed: Under 15°C and during 16-64 h after death, y=-3.027×10(-5)x(3)+0.003x(2)-0.096x-10.625 (R a (2)=0.992, P<0.001); under 25°C and during 8-56 h after death, y=-2.921×10(-5)x(3)+0.002x(2)-0.059x-11.186 (R a (2)=0.989, P<0.001); under 35dgC and during 4-36 h after death, y=-9.769×10(-5)x(3)+ 0.005x(2)-0.117x-11.166 (R a (2)=0.991, P<0.001). The changes in ATP levels in blood collected from right ventricle of rabbit cadavers showed relatively stable and regular degradation within 72 h after death at different temperatures.

[Correlation between the changes of oxidation reduction potential values and postmortem interval of heart blood in rabbits after death].

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.

[Iron and ferritin changes in multiple organs failure after trauma].

OBJECTIVE: To investigate the changes of iron content in serum and liver, ferritin content in serum, percentage of myeloperoxidase (MPO) positive granulocyte in rabbits after different serious trauma and to explore the relationship between these changes and multiple organ failure (MOF). METHODS: Rabbit trauma models were established. Iron content in serum and liver, ferritin content in serum and the percentage of MPO positive granulocyte were measured at different time after trauma. RESULTS: After trauma, iron content in serum decreased sharply in early period (12-36h) and increased gradually to normal level in mild traumatic group after 60 h. Iron content in serum remained lower level in severe traumatic and death group 60 h after trauma. Iron content in liver obviously increased in death group. The changes of ferritin content in serum in mild traumatic were not obvious. Ferritin contents in serum in severe injury group and death group were slightly higher in early period and decreased in later period. The percentage of MPO positive granulocyte increased in early period after trauma. The percentage began to decrease 6 d after trauma and returned to normal level in mild traumatic group. The percentage obviously was significantly lower than normal levels in severe traumatic group and death group 6 d after trauma. Some rabbits died 60 h-6 d after severe trauma, and the pathological changes in the other organs were consistent with MOF. CONCLUSION: Trauma can cause the serum iron, ferritin levels and percentage of MPO positive granulocyte changes. Severe trauma can cause uncompensated changes of these indicators, which could be the main mechanisms of MOF and death.

[Analysis of the changes of amide A in rabbit heart after death by FTIR spectroscopy].

OBJECTIVE: To explore the relationship of changes of amide A in rabbit heart and the postmortem interval (PMI) by FTIR spectroscopy technique. METHODS: Thirty-two rabbits were sacrificed and the hearts were sampled at 20 degrees C within 48 h postmortem points. All samples were sliced and tested by FTIR spectroscopy technique. The images of amide A were created by FTIR spectroscopic imaging. The positive and negative area ratios of amide A were analyzed using imaging analysis system. RESULTS: The positive and negative area ratios declined regularly with the prolongation of death time in 48 h. There was a significant quadric relationship between the area ratios (y) of amide A (positive and negative area) and PMI(x). The regression equation was y = 0.001x2-0.038x + 0.747(R2 = 0.940). CONCLUSION: The ratios of positive and negative area of amide A showed a strong correlation with PMI and could be used to estimate PMI.

[Estimation of postmortem interval with single-voxel proton 1H-MR spectroscopy at different temperature].

OBJECTIVE: To find an objective method for estimation of postmortem interval (PMI) with single-voxel proton MR spectroscopy at different temperature. METHODS: Changes of metabolite peak area and peak area ratio of the N-acetylaspartate (Naa), choline (Cho) and total creatine (Cr) in the brain of 24 rabbit models were measured by 1H-MR spectroscopy (1H-MRS) at 0.5, 1, 2, 4, 6, 8, 12, 16 and 24 h, respectively after death. RESULTS: Naa and Cr decreased continuously with the extension of PMI, and the ratios of Naa/Cr and Cho/Cr also decreased continuously with the extension of PMI within 24 h. The quadratic polynomial regression equation is y=0.0019x2-0.803x+1.4498 (R2=0.962) (Equation 1) with the Naa/Cr used as an independent variable, while the quadratic polynomial regression equation is y=-0.0024x2+0.926x+1.1777 (R2=0.986) (Equation 2) with the Cho/Cr used as an independent variable. The average deviations were about 2.10-37.90 min and 1.69-40.87 min, respectively if the PMI was estimated by Equation 1 and Equation 2, respectively. CONCLUSION: Our study indicates that there is a strong correlation between Naa/Cr, Cho/Cr and PMI, which may be used for estimation of PMI at different temperature.

Myocardial lesions after long-term administration of methamphetamine in rats.

OBJECTIVE: To demonstrate the myocardial lesion associated with long-term administration of methamphetamine in rats. METHODS: The experimental models of intoxication of methamphetamine were established in Sprague-Dawley rats. Methamphetamine hydrochloride (3 mg x kg(-1) x d(-1)) was subcutaneously injected to rats in methamphetamine-treated group (n = 16), and normal saline at the same dose was injected to rats in control group (n = 16). After 1 week and 8 weeks of injection, 8 rats in each group were sacrificed and their hearts were examined with light microscopy and electron microscopy, respectively. RESULTS: After 1 week of methamphetamine exposure, foci of contraction band and cellular degeneration were present in subendocardial myocardium. Cellular degeneration, myocytolysis, and contraction band necrosis became prominent and extensive in methamphetamine-treated rats after 8 weeks. Hypertrophy, intracellular vacuolization, and fibrosis were also observed. The ultrastructural feature showed marked swelling and degeneration of mitochondria, enlargement of sarcoplasmic reticulum, and dissolution of myofilaments. No obvious cardiac myocyte lesions were observed in rats of control group. CONCLUSION: Methamphetamine abuse daily for a long time may result in an increased risk of cardiovascular lesions similar to cardiomyopathy.

Alterations of trace elements (Zn, Se, Cu, Fe) and related metalloenzymes in rabbit blood after severe trauma.

To investigate the status of the trace elements (TEs) and related metalloenzymes activities in the injury and repair process after severe trauma, we established a rabbit model of severe trauma whose Injury Severity Score (ISS) was 22. Concentrations of blood selenium (Se) and serum copper (Cu), zinc (Zn), iron (Fe), and ferritin were measured on D0 (before injury), and day (D) 1, D2, D3, D6, D9, D14, D21, D28 after trauma, respectively. The activities of glutathione peroxidase (GPx), Cu/Zn superoxide dismutase (Cu/Zn-SOD), myeloperoxidase (MPO), the contents of lipid peroxidation product malondialdehyde (MDA) and serum biochemical profile were detected synchronously. In addition, the morphologic changes of major organs were observed at different time intervals. Results showed that blood Se and serum Zn, Fe contents decreased significantly within 2 weeks after injury. Serum Cu concentration was significantly reduced on D1 but normalized quickly. Serum ferritin level increased during the first week while following an obvious decrease thereafter. The blood GPx activity dropped markedly from D1 to D6, the serum Cu/Zn-SOD activity decreased on D1 and then increased significantly within 2 weeks, and the blood MPO-positive stained cells increased within a week after trauma and followed by a decrease from D14 to D21. The serum MDA increased significantly on D6. Seven of 34 rabbits died in 4-6 days after injury. Biochemistry values and pathological features revealed these rabbits died of multiple organ dysfunction syndrome (MODS). Our experiment suggested that the circulating TEs status is dramatically modified in response to trauma, which might be a factor in MODS.

[Estimation of postmortem interval with multivoxel-voxel proton 1H-MR spectroscopy].

OBJECTIVE: The purpose of our study was to evaluate the postmortem interval with multi-voxel 1H-MR spectroscopy. METHODS: Twelve healthy rabbits were studied and the quantities of N-acetylaspartate, total choline, phosphocreatine and creatine were measured by 1H-MR spectroscopy after death at 0.5, 1, 2, 4, 6, 8, 12, 16, and 24 h. RESULTS: The levels of Naa/Cr and Naa/Ch decreased following death, while the level of Ch/Cr increased initially and then decreased following death. CONCLUSION: Multi-voxel proton MR spectroscopy for Naa/Cr and Ch/Cr metabolic ratio could be used in future postmortem interval studies.