Distinguishing true from pseudo hematoma in the cervical spinal canal using postmortem computed tomography.

Spinal cord injury is difficult to detect directly on postmortem computed tomography (PMCT) and it is usually diagnosed by indirect findings such as a hematoma in the spinal canal. However, we have encountered cases where the hematoma-like high-attenuation area in the cervical spinal canal was visible on PMCT, while no hematoma was observed at autopsy; we called it a "pseudo hematoma in the cervical spinal canal (pseudo-HCSC)." In this retrospective study, we performed statistical analysis to distinguish true from pseudo-HCSC. The cervical spinal canal was dissected in 35 autopsy cases with a hematoma-like high-attenuation area (CT values 60-100 Hounsfield Unit (HU)) in the spinal canal from the first to the fourth cervical vertebrae in axial slices of PMCT images. Of these 22 had a hematoma and 13 did not (pseudo-HCSC). The location and length of the hematoma-like high-attenuation and spinal cord areas were assessed on reconstructed PMCT images, true HCSC cases had longer the posterior hematoma-like area and shorter the spinal cord area in the midline of the spinal canal (P < 0.05). Furthermore, we found that true HCSC cases were more likely to have fractures and gases on PMCT while pseudo-HCSC cases were more likely to have significant facial congestion (P < 0.05). We suggest that pseudo-HCSC on PMCT is related to congestion of the internal vertebral venous plexus. This study raises awareness about the importance of distinguishing true HCSC from pseudo-HCSC in PMCT diagnosis, and it also presents methods for differentiation between these two groups.

Quantitative analysis of respiratory viral distribution in forensic autopsy cases.

Respiratory viruses can cause fatal systemic infections; therefore, post-mortem diagnosis is essential in forensic autopsy cases. However, little is known regarding the distribution of respiratory viruses in the body. In this study, we investigated the anatomical distribution of respiratory viruses in 48 forensic autopsy cases suspected of viral infections at our institute. Fast Track Diagnostics (FTD) Respiratory Pathogens 21 was used as a screening test for 20 respiratory viruses in nasopharyngeal swabs. In cases with positive results for virus detection by the screening test, the detected viruses were quantified in body fluid and organ specimens by virus-specific real-time reverse transcription polymerase chain reaction (RT-PCR) and digital PCR. Viruses were detected in 33 cases, with the viral distribution and load differing among the cases. Since various respiratory viruses were detected from the nasopharyngeal swab and its viral load was higher than those of other body fluid specimens, the nasopharyngeal swab was suggested as a useful specimen for the post-mortem detection of respiratory viruses. Viruses were detected in almost all specimens including the serum in six cases. Considering the viral distribution in the body, pathological findings, and ante-mortem symptoms, these cases were presumed to be systemically infected, having died in the acute infection phase. In conclusion, the anatomical distribution of respiratory viruses can help indicate ante-mortem systemic conditions and the cause of death.

An autopsy case of COVID-19-like acute respiratory distress syndrome after mRNA-1273 SARS-CoV-2 vaccination.

We report the first case with COVID-19-like acute respiratory distress syndrome after mRNA-1273 SARS-CoV-2 vaccination. An 88-year-old woman developed dyspnea several hours after vaccination with the second dose of mRNA-1273. She was hospitalized on day nine due to worsening dyspnea. Chest computed tomography showed bilateral ground-glass opacities and consolidations, mainly in the peripheral lung areas. Repeat polymerase chain reaction tests for SARS-CoV-2 were negative, although the serum level of antibodies against spike protein was extremely elevated. Her condition did not improve with high-dose corticosteroids and high-flow nasal cannula oxygen therapy; she died on day 18. Autopsy findings revealed very early-phase diffuse alveolar damage in the whole lung without other lung diseases. The clinical and pathological findings suggested vaccine-induced acute respiratory distress syndrome. Serological and pathological tests might be useful to differentiate the disease from COVID-19.

Kinetics and distribution of benzalkonium compounds with different alkyl chain length following intravenous administration in rats.

Benzalkonium chloride is widely used in disinfectants. Several toxicological and fatal cases have been reported; however, little is known about its kinetics and distribution. We investigated the kinetic characteristics and distribution of benzalkonium cation (BZK) based on the length of the alkyl chains C12, C14, and C16. Rats were treated intravenously with BZK solution (dose, 13.9 mg/kg) containing equal amounts of the three homologues. Kinetic parameters in the blood were assessed, and BZK distribution in the blood and tissues was examined both in rapid intravenous (IV) and drip intravenous (DIV) administrations. BZK concentrations were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). BZK with longer alkyl chains showed lower elimination tendencies and remained in the blood for a longer duration. Concentrations of BZK were higher in the heart, lung, spleen, and kidney than those in the blood, and lower in the brain and fat. In both the IV and DIV groups, the lung, liver, spleen, and fat samples showed higher concentrations of the longer alkyl chains (BZK-C12 < -C14 < -C16), and the opposite trend was observed in the kidney (BZK-C16 < -C14 < -C12). Only the heart and muscle samples displayed the homologues in ratios comparable to the original administered solutions. Differences between IV and DIV groups could be identified by comparing concentrations of BZK homologues in the heart, lung, spleen, and kidney samples. We found that the kinetics and distribution of BZK were influenced by the alkyl chain length, and analysing each BZK homologues in blood and tissue samples may provide useful information.

Identification of aortic injury site using postmortem non-contrast computed tomography in road traffic accident.

In high-speed motor vehicle accidents, it is necessary to investigate the manner of death. Postmortem computed tomography (PMCT) provides important information on the mechanism of death, but identification of the aortic injury is still challenging on non-contrast PMCT. A man in his 50s had multiple injuries on the face and chest in the high-speed motor vehicle accident. The traumatic aortic rupture was clearly depicted on thin-slice and multiplanar reformation PMCT images. Traumatic aortic disruption was confirmed by forensic autopsy. The high contrast between the aortic wall and the lumen visualized the traumatic rupture in the distal aortic arch. For the evaluation of aortic rupture on PMCT, it may be important to trace the continuity of the high-density aortic wall by reviewing thin-slice CT and multiplanar reformation images.

The derivation of predictive equations to speculate the post-mortem interval using cases with over 20-mL pleural effusion: A preliminary study.

Often, pleural effusion is noted at autopsy when the cause of death is drowning or diseases such as heart, renal and liver failure. Several studies have established a correlation between the concentrations of electrolytes in pleural effusion and the post-mortem interval (PMI) or those concentrations and drowning site. The present study aims to investigate the relationship between the amount of pleural effusion, concentrations of electrolytes and total protein in pleural effusion, by integrated interpretation using various factors such as the deceased's gender, age, cause of death, drowning site, PMI and body temperature. We included 40 cadavers (26 male, 14 female) with >20-mL pleural effusion, which were categorised into four groups as follows: freshwater drowning; brackish water drowning; seawater drowning (drowning group); and not drowning. An equation derived to assess the lung weight revealed that the drowning site affected the lung weight. An equation for the amount of pleural effusion in the drowning group for the first time revealed that the amount of pleural effusion was directly proportional to the PMI. Using an equation to assess the PMI, we could estimate the PMI within 13.0-13.2 h in cases with >20-mL pleural effusion. Despite a small number of cases in the present study, we attained exciting results from the integrated statistical analysis.

Predictive equation for post-mortem interval using spectrophotometric values of post-mortem lividity: A pilot study.

The colour of post-mortem lividity and control skin of 86 cadavers was measured spectrophotometrically to obtain L* (value), a* (chroma) and b* (hue) values. In addition, left heart blood (n = 58), right heart blood (n = 57) and blood from the femoral vein (n = 21) were measured. Using these data, we analysed the relationship between post-mortem lividity, control skin and blood colours. L* of post-mortem lividity (L*p) and control skin (L*c) were strongly correlated ( r = 0.64). a* and b* of post-mortem lividity (a*p and b*p) significantly increased with an increasing post-mortem interval (PMI) but r2 values were low (0.11 and 0.070, respectively). Predictive equations for post-mortem lividity colour (L*p, a*p and b*p) were developed using control skin colour (L*c, a*c and b*c) and autopsy findings for the first time. The predictive equation for L*p explained almost 65% of the observed L*p. We created predictive equations for PMI with and without blood colour values, and the most accurate equation, which did not use blood colour values, made it possible to estimate PMI within ± 10.29 h. Further study of these equations will help us to understand the factors that affect post-mortem lividity colour and increase the accuracy of equations for predicting post-mortem lividity colour and PMI.

Predictive equation to estimate post-mortem interval using spectrophotometric blood-colour values.

Forensic pathologists use post-mortem phenomena to estimate the post-mortem interval (PMI). We have reported on the usefulness of post-mortem lividity spectrophotometric values to estimate PMIs. Here, we focused on blood colour, looking for associations between blood colour, age and PMI. We generated predictive equations for blood-colour values and the PMI. We included data from a total of 129 cadavers (84 males and 45 females). We measured the colour of 124 left ventricular blood ( L*l, a*l, b*l), 123 right ventricular blood ( L*r, a*r, b*r) and 57 femoral blood ( L*f, a*f, b*f) samples. We found no significant associations between blood colour and age or between blood colour and the PMI, but the values of a*l, b*l, a*r and b*r were significantly increased with increased age, and those of L*f, a*f and b*f were significantly decreased with increased PMI. We created equations to estimate blood colour. The equations for femoral blood colour had higher adjusted R2 values and lower root mean square error values than those for left and right ventricular blood colours. We generated equations to estimate PMIs using blood-colour values and autopsy findings. Our estimated PMIs up to 67 hours had accuracies within 8.84 hours, without measuring post-mortem lividity colour or considering the age of the deceased. This is the first study to estimate PMIs based on blood-colour spectrophotometric values.

An Autopsy Case of Injuries Caused by Automobile Dragging for a Distance of 3.4 km Without Thoracoabdominal Organ Injuries.

Dragging injuries caused by automobiles involved in an accident are occasionally reported; however, those without injury to the thoracoabdominal organs are rare. We present an autopsy case of a man in his 20s found dead on the road after being dragged by a passenger automobile for a distance of 3.4 km. The accident caused fatal dragging injuries but no thoracoabdominal injuries. The victim appeared to be drunk and was lying on the road in front of the parked automobile. Dragging injuries are a unique type of traffic accident that sometimes result from limited and poor visibility due to darkness, rain, or fog. In particular, lying on the road in a drunken state is a specific risk factor for dragging injuries. The dragging distance, road-surface properties, strength of pressure applied by the underbody of the automobile, and the victim's posture are considered to affect the distribution and degree of dragging injuries. Based on autopsy findings and eyewitness testimonies, we discuss the injury mechanism and attempt to reconstruct the accident.

An experimental study of postmortem decomposition of methomyl in blood.

Methomyl (S-methyl-1-N-[(methylcarbamoyl)oxy]thioacetimidate) is a carbamate pesticide. It has been noted that in some cases of methomyl poisoning, methomyl is either not detected or detected only in low concentrations in the blood of the victims. However, in such cases, methomyl is detected at higher concentrations in the vitreous humor than in the blood. This indicates that methomyl in the blood is possibly decomposed after death. However, the reasons for this phenomenon have been unclear. We have previously reported that methomyl is decomposed to dimethyl disulfide (DMDS) in the livers and kidneys of pigs but not in their blood. In addition, in the field of forensic toxicology, it is known that some compounds are decomposed or produced by internal bacteria in biological samples after death. This indicates that there is a possibility that methomyl in blood may be decomposed by bacteria after death. The aim of this study was therefore to investigate whether methomyl in blood is decomposed by bacteria isolated from human stool. Our findings demonstrated that methomyl was decomposed in human stool homogenates, resulting in the generation of DMDS. In addition, it was observed that three bacterial species isolated from the stool homogenates, Bacillus cereus, Pseudomonas aeruginosa, and Bacillus sp., showed methomyl-decomposing activity. The results therefore indicated that one reason for the difficulty in detecting methomyl in postmortem blood from methomyl-poisoning victims is the decomposition of methomyl by internal bacteria such as B. cereus, P. aeruginosa, and Bacillus sp.

Temporal changes of the adrenal endocrine system in a restraint stressed mouse and possibility of postmortem indicators of prolonged psychological stress.

We investigated temporal changes of adrenal endocrine systems through the hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenomedullary (SA) axis in restraint stressed mice. Restraint stress for 1 day to 3 weeks caused a significant increase in serum levels of ACTH and glucocorticoids accompanied with an increase in adrenal weights, indicating activation of the HPA axis. Reflecting the overproduction of glucocorticoids, adrenal cholesterol content decreased. Moreover, adrenal gene expression involved in cholesterol supply, including scavenger receptor-class B type I, HMG-CoA reductase, and hormone-sensitive lipase, was increased over the same period. After 4 weeks stress, all of these changes returned to control levels. In contrast, adrenal gene expression of chromogranin A, which is cosecreted with catecholamine via the SA axis, was increased with 1 day to 2 weeks of stress, and decreased with 3-4 weeks of stress. Our results suggest that analyses of adrenal endocrine systems based on the combination of several markers examined here would be useful for not only proving prolonged psychological stress experience but also determining its duration.

Anaphylactic shock caused by sting of crown-of-thorns starfish (Acanthaster planci).

A 40s-year-old woman with previous history of injury due to contact with crown-of-thorns starfish, Acanthaster planci, was stung on the right middle finger. After immediately losing consciousness, she died 13 h after injury despite intensive medical treatment. Examination of the respiratory system revealed narrowing due to severe edema of the laryngopharynx, as well as alveolar hemorrhage, eosinophilic infiltration, and extensive neutrophil and eosinophil aggregation in the intravascular lumen of the lungs. Examination of the liver revealed severe diffuse hepatocellular necrosis and extremely high levels of liver transaminases, indicating severe liver damage. Based on these findings, we concluded that she had died from anaphylactic shock induced by circulation of crown-of-thorns starfish venom in the bloodstream. Injurious contact with the spine of the crown-of-thorns starfish can cause severe symptoms as well as systematic reactions, including anaphylaxis. To our knowledge, this is the first case of anaphylactic shock or death caused by human contact with the crown-of-thorns starfish reported in the English-language literature. Although rare, anaphylaxis due to injury by marine animals is potentially fatal. Saving lives requires providing education regarding prevention and enabling prompt response to possible anaphylaxis, including preparation of adrenaline for auto-injection.

Detection of imidacloprid in biological fluids in a case of fatal insecticide intoxication.

Here, we describe a high-performance liquid chromatography/photodiode array detector method for the detection of imidacloprid in biological fluids in a case of suicide by ingestion of liquor mixed with Admire® Flowable insecticide (containing 20% imidacloprid). A plastic bottle containing a cloudy liquid (concentration of ethanol in the liquid was 150 mg/ml and that of imidacloprid was 50 mg/ml) was found near the decedent. The biological fluids collected at autopsy were prepared by deproteinization with acetonitrile. Zolpidem was used as an internal standard. The concentrations of imidacloprid in femoral blood and cerebrospinal fluid were 105 and 58.5 µg/ml, respectively. Ethanol was also detected in the samples, with concentrations of 1.0 mg/ml in femoral blood and 1.4 mg/ml in cerebrospinal fluid.

Morphologic investigation of injury caused by locally applied negative pressure in a rat model.

Although some previous studies have reported patients who developed compartment syndrome or died because of locally applied negative pressure, no detailed investigation of pathologic changes caused by negative pressure-induced injury has been reported in the literature. The main purpose of this study was to examine the morphologic characteristics of injury caused by local negative pressure and correlate these with systemic changes. A total of 30 male Wister rats were used. Animals were randomly assigned to 6 groups. Negative pressure was applied to the right hindlimb of each animal in each group for periods of 0 (sham-operated), 30, 60, 90, 120, or 180 min using a vacuum pump. Macroscopic and microscopic changes induced by local negative pressure were already observed after 30 min and were exacerbated with time. The proportion of muscle degeneration was highest in the deep tissues, irrespective of exposure time. The observed increase in the weight of the injured hindlimb at 180 min was caused by an approximately 30% fluid shift to the hindlimb, demonstrating that the application of negative pressure to the hindlimb of rats can induce hypovolemic shock. We here reveal the morphologic changes induced by local negative pressure and discuss possible mechanisms of negative pressure-induced injury.

Peritoneal bleeding due to percutaneous transhepatic gallbladder drainage: An autopsy report.

A 77-year-old man underwent percutaneous transhepatic gallbladder drainage (PTGBD) for acute cholecystitis as a preoperative procedure; however, he suddenly suffered cardiopulmonary arrest 4 h after the PTGBD and died. There were three centesis scars for the PTGBD, and only one pathway from the most dorsal centesis scar reached the gallbladder. Microscopically, the PTGBD pathway crossed and injured the intrahepatic arterial wall, and hepatic parenchymal bleeding extended along the PTGBD pathway to the inferior surface of the liver. Blood flowed to the peritoneal cavity through a small gap between the liver and gallbladder. Consequently, the PTGBD caused lethal bleeding. When the percutaneous transhepatic cholangio drainage/PTGBD pathway runs close to vessels near the liver surface, it might be necessary to deal with the possibility of rapid and lethal peritoneal bleeding.

A transnasal intracranial stab wound by a plastic-covered umbrella tip.

A 48-year-old man died from a transnasal intracranial stab wound caused by an umbrella. The track of the stab passed from the right nostril, through the sphenoid sinus, the left side of the sella turcica and anterior clinoid process, and finally reached the surface of the brain. The stab wound crossed the left internal carotid artery, causing an exsanguination and aspiration of blood into the airway, resulting in death. It is extremely rare that an umbrella tip used during a struggle would stab the nostril of the victim. Transnasal intracranial stab wounds can be overlooked and require sensitive handling.

An autopsy case of suction injury.

The right upper extremity of a 38-year-old man was entrapped in an underwater intake of a water duct of a dam reservoir, and he died despite being promptly rescued. His right upper extremity was swollen and exhibited purplish-red discolourations. The skin had numerous blisters and increased tension. Severe subcutaneous and muscle bleeding were observed in the right upper extremity. The circumference and volume of the right upper extremity were approximately 1.2 and 1.4 times, respectively, that the circumference and volume of the left upper extremity. The increase in weight of the right extremity was calculated to be approximately 2.1 kg; this finding indicates a severe decrease in the victim's central blood volume. Furthermore, it is possible that much more than 2.1 kg of blood accumulated in the upper extremity upon exposure to vacuum pressure. We conclude that the victim died of circulatory collapse that was attributable to haemorrhage and re-distribution of blood as a result of vacuum pressure on the right upper extremity. Thus, we have examined the cause of death and the effects of vacuum pressure on the human body.

Fatal propeller injuries: three autopsy case reports.

Most propeller injuries occur at water recreational facilities such as those with provision for water skiing, boat racing, skin and scuba diving. Propeller injuries resulting from nautical accidents can be fatal. The sharp blades of propellers rotating at high speeds cause multiple and serious injuries such as deep laceration, chop wounds, bone fractures and mutilation of extremities. We present the autopsy reports of three people who died after colliding with boat propellers.

Characteristic features of injuries due to shark attacks: a review of 12 cases.

Shark attacks on humans might not occur as often as is believed and the characteristic features of shark injuries on corpses have not been extensively reviewed. We describe the characteristic features of shark injuries on 12 corpses. The analysis of these injuries might reveal the motivation behind the attacks and/or the shark species involved in the attack. Gouge marks on the bones are evidence of a shark attack, even if the corpse is decomposed. Severance of the body part at the joints without a fracture was found to be a characteristic feature of shark injuries.