Trends in mortality rates and correlations between intracranial injuries and external causes: A Japanese population study.

The age-standardized incidence of head trauma in 2016 was 369 per 100,000 people worldwide. The Western Pacific region, including Japan, had the highest incidence. This study aimed to extract ICD-10 code data for intracranial injury (S06) and external causes of morbidity and mortality (V01-Y89), analyze their characteristics and interrelationships, and contribute to these diseases' prevention, treatment, and prognosis. The number of deaths according to injury type and external cause type of intracranial injury published by the Japanese government was statistically analyzed using JoinPoint, and univariate distribution and multivariate correlation were conducted using JMP Software. From 1999-2021, there was a downward trend in the number of deaths because of intracranial injuries: mortality from intracranial injuries was higher among those aged ≥65 years. Conversely, mortality from intracranial injuries was lower among those aged ≤14 years. Among deaths from intracranial injury, mortality from diffuse brain injury and traumatic subdural hemorrhage was more common. Among deaths from external causes of intracranial injury, mortality from falls, transport accidents, and other unforeseen accidents was more common. Mortality because of intracranial injuries increased significantly during the 2011 Great East Japan Earthquake. For some age groups and sexes, there were significant inverse correlations of mortality with traumatic subdural hemorrhage and traumatic subarachnoid hemorrhage for transport accidents, intentional self-harm and assault, and diffuse brain injury and focal brain injury for falls. We believe that the data presented in this study will be useful for preventing and treating intracranial injuries and for developing administrative measures to reduce intracranial injuries.

Detection of methamphetamine in mouse femurs exposed to high temperature.

Bone samples are valuable for examining the cause of death and circumstance leading up to death when body fluids are not available for forensic toxicological analysis. Examined were heat-induced changes in methamphetamine and amphetamine concentrations in femurs removed from methamphetamine-injected mice to determine if the burned bones could be used for toxicology testing. The femurs were heated at 100°C, 300°C, or 500°C for 10 or 30 min. The tissue structure of the heated femurs was preserved at 100°C for 30 min but was destructed at higher temperatures. Methamphetamine and amphetamine were detected in femurs heated at 100°C for 10 min, 100°C for 30 min, and 300°C for 10 min (with methamphetamine and amphetamine concentrations ranging from 0.36 to 35 µg/g and 0.54 to 47 µg/g, respectively). Methamphetamine and amphetamine were detectable when heated above their decomposition temperature as a result of limited heat transfer do to protection provide by the femoral muscle. Thus, the bone could be a useful analytical sample in cases of burn-related deaths, where it is difficult to collect body fluids.

Analysis of the pathogenesis of acute necrotizing esophagitis (black esophagus): A report of three autopsy cases.

Acute necrotizing esophagitis (ANE) is a rare condition characterized by black discoloration of the esophageal mucosa. We describe three autopsy cases of ANE, also known as black esophagus. The black discoloration was confined to the esophageal mucosa rather than to the gastric mucosa. The histological findings of brown pigmentation and acute inflammation led to an ANE diagnosis. The immediate cause of death was certified as ANE in all cases. In the three cases, one had hypertension, diabetes, and multiple cerebral infarctions, another had alcoholism, whereas the pre-existing condition was unknown in the remaining patient. Petechial hemorrhages were found on the gastric mucosa of all three patients as a finding of terminal hypothermia. In one case, frequent vomiting was observed prior to death. Blood alcohol was detected (the patient had been drinking immediately prior to death), and the onset of ANE was considered to have occurred several hours before death. The findings indicate that ANE occurs shortly before death in combination with frequent vomiting and terminal hypothermia in the setting of cerebrovascular disease or alcoholism.

Analyses of physical factors that contribute to the blood carboxyhemoglobin saturation in autopsy cases of house fire fatalities.

The authors analyzed data from forensic autopsies of 75 patients who died as a result of house fires to clarify the physical factors that affect blood carboxyhemoglobin (COHb) saturation. Blood COHb saturation levels were significantly lower in patients who survived in the hospital. No significant differences were found in the blood COHb saturation levels between patients who died immediately at the scene and those who were pronounced dead at the receiving hospital without heartbeat being restored. The COHb saturation levels were significantly different among the groups of patients classified by the amount of soot. Although age, coronary artery stenosis, and blood alcohol concentration did not significantly affect blood COHb saturation, on comparing patients who died in the same fire, lower COHb saturation was observed in two patients, one with severe coronary artery stenosis and other with severe alcohol intoxication. To accurately interpret blood COHb saturation during forensic autopsy, the heartbeat status (present or absent) at the time of the rescue and the amount of soot in the trachea must be determined. Low levels of COHb saturation may be observed in fatalities with severe coronary atherosclerosis or severe alcohol intoxication.

Changes in the number of traffic collisions during the various waves of COVID-19 infection in Japan.

An analysis of the national traffic collision trends in Japan for the January 2018 to June 2022 period using existing statistical data indicates that the number of traffic incidents, injuries, and fatalities decreased over time. After the outbreak of COVID-19 in December 2019, traffic volume decreased. In this study, to explore how the COVID-19 pandemic correlates with traffic collisions, we used the Spearman rank correlation of non-parametric statistical test to compare the number of COVID-19 infections with the number of traffic collisions. The number of COVID-19 infections showed a significant inverse correlation with the number of traffic collisions nationwide, in some regions, and in some prefectures. When the number of COVID-19 infections increased, a State of Emergency or Semi-Emergency Spread Prevention Measures were repeatedly declared. We submit that these measures along with the restrictions on the population's autonomy and movement to prevent the spread of infection, reduces the number of traffic incidents, injuries, and fatalities owing to a decrease in traffic volume. Therefore, these lessons learned from the COVID-19 pandemic advocate that regulation of vehicle traffic volume is an effective means of reducing the occurrence of traffic collisions. These results can be applied to future policy development to support road safety improvements during unique events.

Gene expression in meningeal lymphatic endothelial cells following traumatic brain injury in mice.

Meningeal lymphatic vessels transport both the cerebrospinal fluid and interstitial fluid to the deep cervical lymph nodes. Traumatic brain injury (TBI) is accompanied by meningeal injury. We hypothesized that the TBI-induced meningeal injury would damage lymphatic vessels and affect brain function. We observed altered gene expression in meningeal lymphatic endothelial cells (LECs) in a mouse model of TBI. Through flow cytometry-based cell sorting, meningeal LECs were obtained from a mouse model of controlled cortical impact 3 days after TBI. Microarray analysis, real-time polymerase chain reaction assays, and enzyme-linked immunosorbent assays were performed to determine mRNA and protein expression levels in meningeal LECs. The number of meningeal LECs was significantly lower in the injury group than in the sham group 3 days after TBI. Additionally, the mRNA expression of lymphatic vessel endothelial hyaluronan receptor 1 (a specific marker of lymphatic vessels) in meningeal LECs was significantly lower in the injury group than in the sham group. The mRNA and protein expression of FMS-like tyrosine kinase 4 and neuropilin 2 (markers of lymphangiogenesis) in meningeal LECs was significantly higher in the injury group than in the sham group. Our findings indicate that TBI is associated with the impairment of meningeal LECs and meningeal lymphangiogenesis, which implicates lymphatic vessel injury in the pathogenesis of this condition.

Analysis of autopsy cases involving individuals who experienced cardiopulmonary arrest immediately after sustaining minor head injuries.

The authors report five forensic autopsy cases involving individuals who experienced cardiopulmonary arrest immediately after sustaining minor head injuries. Heartbeat was restored in two patients after resuscitation by paramedics. During autopsy, three patients exhibited high blood alcohol levels indicating severe intoxication, two had an unknown blood alcohol status, and all five exhibited parietal bruising of the head. In addition to alcohol intoxication, blunt force impact to the parietal area of the head was believed to be related to the occurrence of cardiopulmonary arrest immediately after head trauma. The absence of secondary brain damage in patients who die from cardiopulmonary arrest immediately after head trauma should be taken into account when diagnosing the cause of death. Additionally, indications for bystander cardiopulmonary resuscitation should be considered for individuals who experience cardiopulmonary arrest due to head trauma.

Effects of Preexisting Diabetes Mellitus on the Severity of Traumatic Brain Injury.

Falls and traffic accidents can cause traumatic brain injury (TBI). Assessment of the injury severity is essential to determine the prognosis or the cause of death. Diabetes mellitus (DM) is a common preexisting disease in elderly adults. We hypothesized that preexisting DM exacerbates TBI secondary to prolonged inflammation. In this study, we investigated TBI-induced changes in nerve function and inflammatory cell migration to the injury site, and the extent of brain contusion in KK-Ay (DM) and C57BL/6J (non-DM) mice. A controlled cortical impact device was used to induce TBI in each mouse. The brain contusion volume was measured using magnetic resonance imaging. Nerve function changes were assessed using the following animal behavior tasks: neurological severity score (NSS), Morris water maze, forced swim test, and beam walking. Immunohistochemical examinations of brain sections were performed to assess the infiltration of neutrophils, astrocytes, microglia, and macrophages, and to detect apoptosis. These experiments were performed on post-injury days 1-90 (over five experiments/time-points in each group). Compared with non-DM mice, DM mice showed significantly greater brain contusion volume, greater deterioration in the NSS, and a higher number of neutrophils, macrophages, and apoptotic cells in the brain tissue specimens. This study indicates that the prognosis of normal mice and DM mice differs, even if they acquire a TBI of the same severity. Therefore, it is important to evaluate patients with TBI for DM and other preexisting diseases in order to provide adequate treatment or to determine the correct cause of death.

Effectiveness of whole genome amplification prior to short tandem repeat analysis for degraded DNA.

Short tandem repeat (STR) analysis is prone to failure as DNA is frequently damaged by various environmental factors; hence, increasing the number of starting templates may constitute a feasible approach to improve STR profiling success. Whole genome amplification (WGA) is often applied to bolster starting template quantity. Moreover, WGA can reportedly be used on degraded DNA samples in forensics. Therefore, we utilized a PCR-based WGA method, termed "modified improved primer extension preamplification" (mIPEP), prior to STR analysis of degraded DNA, as this method is less affected by DNA quantity and quality than most others. Saliva from four volunteers was dried on glass fiber filter papers (paper) and glass slides (glass) and irradiated with UVA light (365 nm). The mIPEP method was initiated using 5, 0.5, and 0.05 ng of DNA following DNA extraction. The DNA degradation index (DI) was calculated based on the ratio of 129 to 41 bp DNA fragments; lower numbers indicate higher degradation. Following mIPEP, STR analysis was performed using the AmpFlSTR Identifiler PCR amplification kit. The number of detectable STR loci, with and without mIPEP, decreased according to reduced DI in a different manner for the various DNA concentrations extracted from paper and glass. Specifically, for the 5 ng DNA sample on paper, at a DI < 0.2, the number of detectable STR loci was greater with mIPEP than without it, owing to fewer locus drop-outs. Similarly, the 0.05 ng DNA sample deposited on paper, at DI ≥ 0.7, exhibited higher numbers of detectable STR loci when prepared using mIPEP owing to fewer allele drop-outs. Moreover, among samples deposited on glass, the 0.05 ng DNA sample at DI ≥ 0.4 afforded a larger number of detectable STR loci when prepared using mIPEP than those without mIPEP, owing to fewer locus drop-outs. These findings suggest that performing mIPEP in accordance with sample DNA condition (e.g., quantity and quality) may lead to increased success of STR analysis. Notably, the conditions identified as most responsive to mIPEP were consistent across both UVA-irradiated and environmentally-damaged sample states. Taken together, our results suggest that applying mIPEP would be beneficial to obtain improved STR profiles under conditions involving severely degraded samples with large quantities of DNA, or with small quantities of DNA albeit with slight degradation.

Senescence-associated-ß-galactosidase staining following traumatic brain injury in the mouse cerebrum.

Primary and secondary traumatic brain injury (TBI) can cause tissue damage by inducing cell death pathways including apoptosis, necroptosis, and autophagy. However, similar pathways can also lead to senescence. Senescent cells secrete senescence-associated secretory phenotype proteins following persistent DNA damage response signaling, leading to cell disorders. TBI initially activates the cell cycle followed by the subsequent triggering of senescence. This study aims to clarify how the mRNA and protein expression of different markers of cell cycle and senescence are modulated and switched over time after TBI. We performed senescence-associated-ß-galactosidase (SA-ß-gal) staining, immunohistochemical analysis, and real-time PCR to examine the time-dependent changes in expression levels of proteins and mRNA, related to cell cycle and cellular senescence markers, in the cerebrum during the initial 14 days after TBI using a mouse model of controlled cortical impact (CCI). Within the area adjacent to the cerebral contusion after TBI, the protein and/or mRNA expression levels of cell cycle markers were increased significantly until 4 days after injury and senescence markers were significantly increased at 4, 7, and 14 days after injury. Our findings suggested that TBI initially activated the cell cycle in neurons, astrocytes, and microglia within the area adjacent to the hemicerebrum contusion in TBI, whereas after 4 days, such cells could undergo senescence in a cell-type-dependent manner.

Delayed death due to traumatic dissection of the common carotid artery after attempted suicide by hanging.

Traumatic dissection of the carotid arteries is a rare cause of delayed death due to hanging. We report a case of delayed death two and a half months following attempted suicide by hanging where the patient was able to talk after being released from neck compression. The cause of death was aspiration pneumonia due to cerebral infarction secondary to traumatic dissection of the left common carotid artery due to attempted suicide by hanging. Carotid artery injuries should be examined in patients who were able to talk after an unsuccessful suicide attempt by hanging but who later died.

Detection of cocaine and metabolites from mouse femur buried in soil.

Drug addicts are frequently involved in committing homicides, and burial in the ground is often performed by offenders for body disposal. Therefore, toxicological analyses of buried bones are vitally important for investigating the cause and circumstance of death. Cocaine concentrations in heart blood, femoral muscle, and femur were measured in mice after injections of 5, 15, and 30 mg/kg cocaine and in femurs buried in soil. The concentrations of cocaine in femurs (253.67-1345.31 ng/g) were higher than those found in heart blood (3.14-28.73 ng/mL) and femoral muscle (76.41-429.76 ng/g). The cocaine concentrations in buried femurs (54.83-388.68 ng/g) were significantly lower than those in unburied femurs (253.67-1345.31 ng/g). Further, cocaine was detected in femurs after being buried for 7-180 days in soil. These findings indicate that cocaine concentrations are higher in bone than in heart blood and femoral muscle and that the concentration decreases after burial in soil.

Dose-dependent mortality involving convulsions due to subarachnoid Urografin® injection in rats.

An ionically hypertonic contrast medium Urografin® was inadvertently administered into the subarachnoid space of an individual and this resulted in convulsions and acute respiratory failure. We examined the effects of subarachnoid Urografin® injections on the rat central nervous system. The onset and frequency of the convulsions, as well as fatality, were dependent on the amount of Urografin® administered. No convulsions were observed in rats receiving injections of hypertonic NaCl solution or saline. The results confirmed that subarachnoid injections of Urografin® cause convulsions and death, as previously reported in human cases, and our study ascertained the causal relationship between the above malpractice and fatal outcomes.

Screening for single nucleotide polymorphisms in highly degraded DNA by using the amplified fragment length polymorphism technique.

Short tandem repeat (STR) analysis is generally used for human identification of forensic samples; however, standard STR analysis sometimes fails to generate full profiles since DNA is frequently degraded by various environmental factors. Recently, single nucleotide polymorphism (SNP) analysis has attracted attention for human identification since the shorter amplicons are better suited for degraded samples. Though various SNP loci are used for analysis of degraded samples, it is unclear which ones are more appropriate. To identify SNPs that were resistant to degradation, we artificially degraded DNA obtained from the buccal swabs of six volunteers and the K562 cell line by heat treatment. Subsequently, the amplified fragment length polymorphism (AFLP) technique was used for SNP screening. We focused on the AFLP bands detected in both the heat-treated and untreated samples, and DNA extracted from these bands was directly sequenced. DNA degradation increased as the duration of heat treatment increased, and no STR profiles could be generated after 6h of heat treatment. When the AFLP band patterns were compared between 6h heat-treated and untreated samples, eight common bands were detected. The sequences of the DNA fragments of these common bands had higher adenine-thymine (A-T) content and included 17 SNPs. The SNPs detected in the heat-treated and untreated samples were considered to be resistant to degradation. Although there was a little information available in databases regarding the nine SNPs identified in this study, this study shows that some of these SNPs might be useful for human identification of extremely degraded DNA.

Quantification of Methamphetamine in Mouse Thighbones Buried in Soil.

Bone samples are used for analysis of drugs in decomposed or skeletonized bodies. Toxicological analyses of buried bones are important for determining the causes and circumstances of death. In this study, methamphetamine and amphetamine concentrations in heart blood, thigh muscles, and thighbones were analyzed using solid-phase extraction with liquid chromatography-tandem mass spectrometry. Methamphetamine concentrations in heart blood, thigh muscle, and thighbone ranged from 0.041 to 0.873 µg/mL, 0.649 to 2.623 µg/g, and 56.543 to 643.371 µg/g, respectively. Thighbone concentrations were significantly higher than those in heart blood or thigh muscles were. Methamphetamine concentrations in buried thighbone (4.010-45.785 µg/g) were significantly lower than those of unburied thighbones were (56.543-643.371 µg/g). Methamphetamine and amphetamine were detected in thighbones buried for 7-180 days. These findings indicate that the methamphetamine concentrations in bone are higher and decrease after burial in soil.

Hippocampal neuronal degeneration in the traumatic brain injury mouse: non-trivial effect of scalp incision.

OBJECTIVES: In experimental models of traumatic brain injury (TBI), posttraumatic hippocampal neuronal degeneration in the cornu ammonis 1 (CA1), and/or the cornu ammonis 3 (CA3) regions are regarded as the most notable phenotypic appearances relating to the pathophysiology of human post-concussion syndrome. However, these morphological changes are often also seen in subjects without TBI, namely 'sham' groups. The frequencies and reasons of appearance of hippocampal neuronal degeneration in mice with TBI and/or sham are not clear. METHODS: We compared the frequencies of hippocampal neuronal degeneration among three groups: TBI (mice with external force impact performed by Marmarou's weight drop model after scalp incision), sham (mice with scalp incision alone), and control (mice with neither external force impact nor scalp incision), using hematoxylin and eosin stain in day 6 (n = 5 in each group.) Isoflurane was used for anesthesia in all mice. RESULTS: The frequencies were 80, 100, and 20% in CA1, and 20, 40, and 60% in CA3, for TBI, sham, and control, respectively. In CA1, a significant difference of the frequency was observed between sham and control (p = 0.048), but not, between TBI and sham (p = 1.000) in Fisher's exact test. In CA3, no significant difference in the frequency was observed between the three groups. CONCLUSION: Scalp incision, rather than external impact force, might affect the CA1 hippocampal neuronal degeneration in mice with TBI. In addition, factor(s) other than external impact force or scalp incision may also cause hippocampal neuronal degeneration in both CA1 and CA3. Careful interpretation is needed concerning hippocampal neuronal degeneration induced by a weight drop device observed in mice with TBI.

Investigation of single nucleotide polymorphism loci susceptible to degradation by ultraviolet light.

DNA in biological fluids is often degraded by environmental factors. Given that single nucleotide polymorphism (SNP) analyses require shorter amplicons than short tandem repeat (STR) analyses do, their use in human identification using degraded samples has recently attracted attention. Although various SNP loci are used to analyze degraded samples, it is unclear which ones are more appropriate. To characterize and identify SNP loci that are susceptible or resistant to degradation, we artificially degraded DNA, obtained from buccal swabs from 11 volunteers, by exposure to ultraviolet (UV) light for different durations (254 nm for 5, 15, 30, 60, or 120 min) and analyzed the resulting SNP loci. DNA degradation was assessed using gel electrophoresis, STR, and SNP profiling. DNA fragmentation occurred within 5 min of UV irradiation, and successful STR and SNP profiling decreased with increasing duration. However, 73% of SNP loci were still detected correctly in DNA samples irradiated for 120 min, a dose that rendered STR loci undetectable. The unsuccessful SNP typing and the base call failure of nucleotides neighboring the SNPs were traced to rs1031825, and we found that this SNP was susceptible to UV light. When comparing the detection efficiencies of STR and SNP loci, SNP typing was more successful than STR typing, making it effective when using degraded DNA. However, it is important to use rs1031825 with caution when interpreting SNP analyses of degraded DNA.

The histopathological structures of the extrapleural hematoma wall: A case report.

Extrapleural hematoma is a rare condition in which blood is present in the extrapleural space, which sometimes causes death due to respiratory failure. Although a single low-density stripe, called a "displaced extrapleural fat sign," can be detected in chest computed tomographic (CT) scans, no reports have confirmed this structure histopathologically. We performed an autopsy on a patient with extrapleural hematoma who died of respiratory failure. An extrapleural fat sign was detected on the antemortem CT. We investigated the wall structure histopathologically. The hematoma wall was composed of parietal pleura, a sub-pleural layer, an extrapleural fat layer and endothoracic fascia. The case indicated that extrapleural hematoma occurs at the endothoracic fascia.

Fatal overdose from synthetic cannabinoids and cathinones in Japan: demographics and autopsy findings.

BACKGROUND: Sixty-one autopsy cases involving cathinones and/or cannabinoids (synthetic cathinones/cannabinoids) use have been reported. However, little is known about the demographics and autopsy findings in fatal synthetic cathinones/cannabinoids users. OBJECTIVES: To elucidate demographic and autopsy findings (i.e. major organ pathology and causes of death) in synthetic cathinones/cannabinoids cases. METHODS: We reviewed forensic autopsy reports in Department of Legal Medicine of Tokyo Women's Medical University (Tokyo, Japan) between 2011 and 2015 (a total of 359). We compared demographic and autopsy findings between synthetic cathinones/cannabinoids and methamphetamine cases (as control subjects). RESULTS: There were 12 synthetic cathinones/cannabinoids cases and 10 methamphetamine cases. Synthetic cathinones/cannabinoids users were significantly younger than methamphetamine users (p < 0.01), and there were no cases that used both synthetic cathinones/cannabinoids and methamphetamine. Acute intoxication and cardiac ischemia were the two most prominent causes of death in both synthetic cathinones/cannabinoids users and methamphetamine users. Excited delirium syndrome and pulmonary aspiration were found only in synthetic cathinones/cannabinoids cases. CONCLUSIONS: The populations of synthetic cathinones/cannabinoids and methamphetamine users who died of an overdose are different in Japan. Acute intoxication, cardiac ischemia, excited delirium syndrome, pulmonary aspiration, and drowning are the major autopsy findings in synthetic cathinones/cannabinoids-related death. Clinicians shuld be aware of these potentially fatal complications in the medical management of synthetic cathinones/cannabinoids users.

Traumatic brain injury decreases serotonin transporter expression in the rat cerebrum.

OBJECTIVES: An association has been postulated between traumatic brain injury (TBI) and depression. The serotonin transporter (SERT) regulates the concentration of serotonin in the synaptic cleft and represents a molecular target for antidepressants. We hypothesized that SERT expression in the brain changes following TBI. METHODS: We performed immunohistochemistry, real-time polymerase chain reaction analysis for mRNA and western blot analysis for protein to examine the time-dependent changes in SERT expression in the cerebrum during the first 14 days after TBI, using a controlled cortical impact model in rats. RESULTS: SERT immunoreactivity in neuronal fibres within the area adjacent to the cortical contusion decreased 1 to 14 days after injury. Significantly decreased SERT mRNA and protein expression were noted in the area adjacent to the cortical contusion 7 days after injury. There were no significant changes in SERT expression in the cingulum of the injured brain. DISCUSSION: The findings of this study indicate that TBI decreases SERT expression in the cerebral cortex. The decreased levels of SERT expression after TBI may result in decreased serotonin neurotransmission in the brain and indicate a possible relationship with depression following TBI.