Prominent black esophagus, Wischnewsky spots, and black duodenum in a fatal hypothermia case with an underlying diabetic ketoacidosis.

Hypothermia can occur in patients with diabetic ketoacidosis (DKA), and these two conditions can exacerbate each other. Fatal hypothermia and DKA have overlapping features and findings such as Wischnewsky spots (WS), black esophagus, basal subnuclear vacuolization in the renal tubule, dehydration, and increased acetone levels. Therefore, it may be challenging to differentiate or clarify the context of these two conditions. Herein, we report a case of a 49-year-old man with type 1 diabetes who was found lying in his house in mid-winter. He experienced cardiopulmonary arrest 10 h after the initial discovery and died at the hospital. On autopsy, florid left cardiac blood was observed. Black discoloration of the distal part of the esophageal mucosa, widespread WS in the gastric mucosa, and black discoloration of the duodenal mucosa were observed. Histologically, neutrophil infiltration in the esophageal mucosa, neutrophil infiltration and bleeding in the gastric mucosa, basal subnuclear vacuolization and Armanni-Ebstein lesion in the renal tubule epithelium in the kidney, and hyalinization of the islets of Langerhans were observed in the pancreas. Blood acetone and ß-hydroxybutyrate levels were 538 µg/mL and 8947 µmol/L, respectively. Glycated hemoglobin A1c and glucose levels were 16.2% and 883 mg/dL, respectively, while C-reactive protein level was 3.64 mg/dL. In conclusion, obnubilation due to DKA was assumed to be the underlying cause of hypothermia, and the combination of these two conditions led to the outcome of death. The concurrent presence of these conditions likely contributed to the conspicuous mucosal findings in the upper gastrointestinal tract.

Relationship between N-terminal pro-brain natriuretic peptide concentration and heart-type fatty acid-binding protein in postmortem urine.

The clinical use of N-terminal pro-brain natriuretic peptide (NT-proBNP) and blood concentrations of heart-type fatty acid-binding protein (HFABP) is well-established in diagnosing heart conditions. However, their applicability in forensics is controversial due to postmortem changes. NT-proBNP and HFABP are excreted in the urine due to their small molecular weights and may be found in postmortem urine samples; however, their correlation has not been evaluated. In this study, we compared the concentrations of urinary NT-proBNP and HFABP in 386 forensic autopsy cases. The urinary NT-proBNP levels were significantly higher in acute myocardial infarction (AMI), congestive heart failure (CHF), sepsis, and hyperthermia cases, with the highest levels in CHF cases. Similarly, HFABP concentration was significantly higher in CHF, sepsis, and hyperthermia cases, with the highest level observed in hyperthermia cases. However, the difference in urinary HFABP levels between the AMI and control cases was not significant. Our analysis revealed a correlation between postmortem urine NT-proBNP and HFABP levels, and the NT-proBNP/HFABP ratio was high in patients with CHF and sepsis cases and low in those with hyperthermia. The difference between the ratios was possibly due to the combined release of ventricular myocardial cells in response to ventricular wall stress and myocardial injury for NT-proBNP, as well as myocardial and skeletal muscle injuries for HFABP. This study, for the first time, demonstrates the utility of postmortem measurements of urinary NT-proBNP and HFABP levels, offering valuable insights for improving the accuracy of postmortem diagnosis in forensic medicine.

Postmortem pericardial fluid sLOX-1 levels and LOX-1 immunostaining in forensic specimens: Relation to cause of death.

Lectin-like oxidized LDL receptor-1 (LOX-1) is the endothelial receptor for oxidized LDL. This receptor's extracellular domain is released into the blood as soluble LOX-1 (sLOX-1) and has been linked to ischemic heart disease (IHD), cerebrovascular diseases (CVDs), obesity, and diabetes. We recently reported that sLOX-1 fluid levels in postmortem pericardial fluid were comparable to clinical values in live patients and that significant increases in sLOX-1 were observed in patients with IHD. However, postmortem serum and urine sLOX-1 levels were higher than serum levels in living patients. Here, we conducted LOX-1 immunostaining in forensic specimens (aorta and heart) and evaluated pericardial fluid sLOX-1 in 221 medicolegal autopsy cases (67 IHD, 11 CVD, 17 inflammatory diseases, and 126 control cases) with a postmortem interval < 72 h to assess the diagnostic efficiency of postmortem pericardial fluid sLOX-1. Furthermore, we evaluated the relationships between pericardial fluid sLOX-1 and body mass index (BMI), blood HbA1c, serum C-reactive protein (CRP), high-density lipoprotein cholesterol (HDL-C), and low-density-lipoprotein cholesterol (LDL-C). LOX-1 immunostaining positivity was found in the aortic intima. Pericardial fluid sLOX-1 levels were considerably higher in patients with IHD and CVD. However, there were no significant differences in patients with inflammatory diseases and controls. No associations between pericardial fluid sLOX-1 and BMI, HbA1c, CRP, HDL-C, or LDL-C were found. These results indicate sLOX-1 utility in the postmortem diagnosis of IHD and CVD.

Effectiveness of Rapid Antigen Testing in Forensic Cases of Severe Acute Respiratory Syndrome Coronavirus 2 Infection, Including Delta Variant.

ABSTRACT: The polymerase chain reaction is indispensable for diagnosing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in forensic cases. However, studies regarding the effectiveness of rapid antigen testing (RAT) in forensic cases remain limited. Therefore, we investigated the efficacy of RAT compared with reverse-transcription quantitative polymerase chain reaction (RT-qPCR) for confirming SARS-CoV-2 infection (including the delta variant). Before the external examination or autopsy, we collected samples from the nasopharyngeal mucosa, which were then assessed via RAT (QuickNavi COVID-19 Ag kit, QuickNavi-Flu+COVID-19 Ag kit) and RT-qPCR. Reverse-transcription quantitative polymerase chain reaction results were positive in 73 of 1255 cases, and 21 cases were identified as those of delta variants. Low RT-qPCR threshold cycle value cases and delta variant infections were more likely to result in coronavirus disease-related deaths. The sensitivity of the QuickNavi COVID-19 Ag kit was 76.32%, and that of the QuickNavi-Flu+COVID-19 Ag kit was 77.14%. The specificity of both RATs was 100%. In QuickNavi COVID-19 Ag kit cases, delta variant cases showed lower sensitivity than non-delta variant cases, even for a similar viral load. Thus, RAT in forensic cases is sufficiently useful as a screening test for SARS-CoV-2 infection. However, RAT carries a risk of false negatives, especially for delta variant cases.

A human tissue-based assay identifies a novel carrion blowfly strain for maggot debridement therapy.

Maggot debridement therapy (MDT) is a form of therapeutic wound treatment in which live fly larvae are used intentionally to debride necrotic tissues. MDT has been widely used to treat chronic wounds in humans or animals, such as diabetic foot ulcers. Larvae of a carrion blowfly, Lucilia sericata (green bottle fly), debride wounds by consuming necrotic tissue and removing pathogenic bacteria, promoting effective wound healing. Most medical L. sericata strains were initially collected from natural environments using animal meat as bait and reared on artificial protein-rich media or ground meat. It remains to be examined which strain would be more appropriate for MDT, whereas any method for evaluating the fly's therapeutic potential in humans has not been available. A feeding assay was developed using minced human tissues obtained from surgical waste. To establish L. sericata strains highly eligible for MDT, carrion fly larvae were collected from 45 corpses subjected to forensic autopsy (such as decomposed bodies). Four corpse-derived L. sericata strains were obtained and evaluated using the feeding assay. One strain showed that its feeding activity was 1.4 times higher than the control strain used in conventional MDT. The body length of the adult fly of the corpse-derived strain was longer than the control, which was consistent with the observation that its cell size was enlarged. The human tissue-based assay developed in this study accurately evaluated the ability of fly larvae to debride necrotic wounds. The L. sericata strain newly established from human corpses harboring high feeding activity may offer a clinically significant improvement in MDT.

Comprehensive Severe Acute Respiratory Syndrome Coronavirus 2 Detection Using Polymerase Chain Reaction and Rapid Antigen Testing in Postmortem Specimens.

ABSTRACT: Polymerase chain reaction (PCR) is indispensable for diagnosing coronavirus disease 2019 (COVID-19) in autopsy cases. In this study, we performed comprehensive reverse transcription quantitative PCR (RT-qPCR) and rapid antigen tests for COVID-19 on forensic postmortem specimens, regardless of the antemortem symptoms and causes of death. Immediately before forensic external examination and autopsy, a wiping solution was collected from the nasopharynx with a dry swab, and rapid antigen testing and RT-qPCR were performed. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was detected by RT-qPCR in 12 of the 487 cases; the infection rate was 2.46%. Of the RT-qPCR-positive cases, 7 were associated with COVID-19-related deaths. Cycle threshold values were not correlated with the cause of death or postmortem time. The sensitivity and specificity of the rapid antigen test were 91.67% and 100.00%, respectively. The RT-qPCR positivity rate of forensic cases was higher than the cumulative infection rate for the entire population. SARS-CoV-2 could be detected with the rapid antigen test and RT-qPCR within 216 hours of death. Because the rapid antigen test showed the same sensitivity and specificity as those observed in clinical practice, the test combined with RT-qPCR may be useful for diagnosing COVID-19 even in postmortem specimens.

Cerebral venous sinus thrombosis associated with COVID-19: an autopsy case report.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus. COVID-19 has been reported to increase the propensity for systemic hypercoagulability and thromboembolism disorders such as cerebral venous sinus thrombosis (CVST). A 66-year-old woman was found dead at her home. She had symptoms of fever, dizziness, and malaise 2 weeks prior to her death. However, her fever declined 3 days before death. Postmortem computed tomography conducted before the autopsy suggested CVST. On autopsy, a massive thrombus was observed from the cortical veins to the superior sagittal sinus and transverse sinus accompanied by a small infarction region in the left parietal region. Although the rapid antigen test was negative, the reverse transcription-quantitative polymerase chain reaction test was positive for SARS-CoV-2, with a cycle threshold (Ct) value of 38.9. The serum C-reactive protein level was 0.532 mg/dL. COVID-19 was the only risk factor for CVST, and no other cause of death was determined. Therefore, the cause of death was determined as acute intracranial hypertension due to CVST associated with COVID-19. The patient died after the symptoms improved, the Ct value of RT-qPCR was 38.9, and the serum C-reactive protein level decreased. Therefore, CVST might have occurred in the convalescent phase of COVID-19 infection.

Accuracy of Urea Nitrogen and Creatinine Measurements in Postmortem Serum and Pericardial Fluid Compared With Antemortem Data.

ABSTRACT: Although several studies have measured urea nitrogen (UN) and creatinine (Cr) concentrations in postmortem serum and pericardial fluid, no recent antemortem biochemical data have been available for forensic autopsy, thereby making the evaluation of the accuracy of postmortem data difficult. This study compared antemortem (from emergency room results before the declaration of death) and postmortem serum UN and Cr concentrations, as well as postmortem serum and pericardial fluid values, in 51 forensic autopsy cases (postmortem interval within 87 hours). Postmortem UN concentrations were strongly correlated with antemortem data. Moreover, no significant difference between pericardial fluid UN concentrations and antemortem data was observed. Postmortem serum and pericardial fluid Cr values were also correlated with antemortem data, although postmortem values were significantly higher than antemortem ones. Given our observation of early postmortem elevation in Cr concentrations, such an elevation was attributed to rigor mortis. In conclusion, the current study demonstrated the utility of postmortem UN and Cr concentrations, in particular of those measured in the pericardial fluid.

Fatal intoxication due to transrectal methamphetamine overdose: A case report.

Methamphetamine (MA) abuse is common in Asian countries. The major ways of abuse include intravenous injection, absorption, and ingestion. Although two cases of survival after transrectal MA administration have been reported in the clinical field, to the best of our knowledge, there is no report of death due to intentional transrectal MA overdose. This is the first report of such a death. A single, 42-year-old male with a history of habitual MA use was found dead at his home. The police found numerous unused injectors in his closet. A rapid test of his urine was positive for MA. The cause of death was unclear, so a medicolegal autopsy was performed. RESULTS: Autopsy findings revealed a tubular plastic container without a lid in the rectum at the time of excision, with a small, open plastic bag inside. MA was detected in both the plastic container and the plastic bag. The MA concentration in the femoral vein blood was enough to cause death, and the cause of death was considered transrectal MA overdose. MA was absorbed through the lower part of the rectum, so the absorbed MA bypassed the liver and was transported directly to the systemic circulation. Since MA is largely metabolized in the liver, the absorbed MA was unaffected by the hepatic first-pass effect and may have caused more rapid and serious intoxication.

Comparison of C-reactive protein levels between antemortem serum and postmortem serum and pericardial fluid.

Biochemical markers undergo postmortem changes that complicate diagnostic measurement. C-reactive protein (CRP) is one marker that is known to be useful in postmortem specimens, with high levels reported in forensic cases of sepsis, trauma, and ketoacidosis. In the present study, we included 30 cases (17 males and 13 females) that underwent forensic autopsy within 80 h of death and had a CRP result from two postmortem specimens (serum from cardiac blood and pericardial fluid) and an emergency room specimen. Antemortem results were taken at a time near to cardiopulmonary arrest and the declaration of death. CRP levels in postmortem serum and pericardial fluid correlated with those in antemortem serum. Although no significant difference was observed between the antemortem and postmortem serum levels, the pericardial level was significantly low and five false negatives were observed. We conclude that postmortem serum is suitable for use in CRP measurement, and in cases with high antemortem CRP levels, postmortem pericardial fluid may be an appropriate alternative.

Rescue from Stx2-Producing E. coli-Associated Encephalopathy by Intravenous Injection of Muse Cells in NOD-SCID Mice.

Shiga toxin-producing Escherichia coli (STEC) causes hemorrhagic colitis, hemolytic uremic syndrome, and acute encephalopathies that may lead to sudden death or severe neurologic sequelae. Current treatments, including immunoglobulin G (IgG) immunoadsorption, plasma exchange, steroid pulse therapy, and the monoclonal antibody eculizumab, have limited effects against the severe neurologic sequelae. Multilineage-differentiating stress-enduring (Muse) cells are endogenous reparative non-tumorigenic stem cells that naturally reside in the body and are currently under clinical trials for regenerative medicine. When administered intravenously, Musecells accumulate to the damaged tissue, where they exert anti-inflammatory, anti-apoptotic, anti-fibrotic, and immunomodulatory effects, and replace damaged cells by differentiating into tissue-constituent cells. Here, severely immunocompromised non-obese diabetic/severe combined immunodeficiency (NOD-SCID) mice orally inoculated with 9 × 109 colony-forming units of STEC O111 and treated 48 h later with intravenous injection of 5 × 104 Muse cells exhibited 100% survival and no severe after-effects of infection. Suppression of granulocyte-colony-stimulating factor (G-CSF) by RNAi abolished the beneficial effects of Muse cells, leading to a 40% death and significant body weight loss, suggesting the involvement of G-CSF in the beneficial effects of Muse cells in STEC-infected mice. Thus, intravenous administration of Muse cells could be a candidate therapeutic approach for preventing fatal encephalopathy after STEC infection.

Postmortem urine concentration of N-terminal pro-brain natriuretic peptide in relation to the cause of death.

The utility of biochemical marker analysis in forensic autopsy cases is still uncertain due to the postmortem changes which they undergo. Thus, research is required to elucidate alternative samples and biochemical markers which are less affected by postmortem changes. Levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) are known to be elevated in congestive heart failure (CHF), acute myocardial infarction (AMI), and sepsis patients. Although NT-proBNP is reportedly excreted into the urine, no study has previously evaluated the diagnostic efficacy of urinary concentrations in a forensic setting. The aim of this study was to evaluate the diagnostic efficacy of NT-proBNP concentration in urine obtained postmortem in a series of forensic autopsy cases. METHODS: Urinary NT-proBNP was measured in 36 AMI, 10 CHF, and 19 sepsis cases, and in 124 control cases (all with postmortem interval [PMI]<72h). RESULTS: Urinary NT-proBNP was significantly higher in AMI, CHF, and sepsis cases than in control cases. Cut-off values for diagnosing AMI, CHF, and sepsis-related fatalities were 98 (sensitivity, 55.6 %; specificity, 73.4 %), 1050 (sensitivity, 80.0 %; specificity, 94.4 %), and 363pg/mL (sensitivity, 84.2 %; specificity, 85.5 %), respectively. Furthermore, we subdivided the control cases according to the death process as either acute death (87 cases) or prolonged death cases (37 cases). Although urine NT-proBNP of CHF and sepsis cases were significantly higher compared with both cases, the concentration in the AMI cases were significantly high only when compared with the acute death cases. CONCLUSION: This study is the first to elucidate the diagnostic utility of NT-proBNP measurement in urine obtained postmortem in a series of causes of death. This study suggests the diagnostic efficacy for AMI, CHF, and sepsis-related fatality in cases in which the PMI was within 72h.

Utility of soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) in the postmortem diagnosis of ischemic heart disease.

PURPOSE: Ischemic heart disease (IHD) is a major cause of death in developed countries. Postmortem IHD diagnosis using biochemical markers is difficult because of the postmortem changes. In the present study, we investigated the utility of soluble lectin-like low-density lipoprotein receptor-1 (sLOX-1) in body fluids obtained from forensic autopsy cases. METHODS: We measured pericardial fluid, urine, and serum sLOX-1 levels; these samples were obtained from medicolegal autopsy cases (n = 149, postmortem interval <72 h), and the utility of these biomarkers postmortem acute IHD diagnosis was evaluated. RESULTS: The pericardial fluid and urine of patients with acute IHD had higher sLOX-1 levels (p < .05) compared to the controls. No significant differences were found between the sLOX-1 level and the degree of coronary atherosclerosis, body mass index, and postmortem interval. CONCLUSION: sLOX-1 levels in pericardial fluid and urine samples obtained postmortem are useful markers of acute IHD.

Development of a dual test procedure for DNA typing and methamphetamine detection using a trace amount of stimulant-containing blood.

Investigation of drug-related crimes, such as violation of the Stimulant Drug Control Law, requires identifying the used drug (mainly stimulant drugs, methamphetamine hydrochloride) from a drug solution and the DNA type of the drug user from a trace of blood left in the syringe used to inject the drug. In current standard test procedures, DNA typing and methamphetamine detection are performed as independent tests that use two separate portions of a precious sample. The sample can be entirely used up by either analysis. Therefore, we developed a new procedure involving partial lysis of a stimulant-containing blood sample followed by separation of the lysate into a precipitate for DNA typing and a liquid-phase fraction for methamphetamine detection. The method enables these two tests to be run in parallel using a single portion of sample. Samples were prepared by adding methamphetamine hydrochloride water solution to blood. Samples were lysed with Proteinase K in PBS at 56°C for 20min, cooled at -20°C after adding methanol, and then centrifuged at 15,000rpm. Based on the biopolymer-precipitating ability of alcohol, the precipitate was used for DNA typing and the liquid-phase fraction for methamphetamine detection. For DNA typing, the precipitate was dissolved and DNA was extracted, quantified, and subjected to STR analysis using the AmpFℓSTR® Identifiler® Plus PCR Amplification Kit. For methamphetamine detection, the liquid-phase fraction was evaporated with N2 gas after adding 20µL acetic acid and passed through an extraction column; the substances captured in the column were eluted with a solvent, derivatized, and quantitatively detected using gas chromatograph/mass spectrometry. This method was simple and could be completed in approximately 2h. Both DNA typing and methamphetamine detection were possible, which suggests that this method may be valuable for use in criminal investigations.

Infant death associated with maternal methamphetamine use during pregnancy and delivery: A case report.

The case described in this report is of a male infant who was found dead in a closet. His mother delivered the infant in the kitchen, left him wrapped in a towel, and called emergency medical services 4days after the delivery. At the autopsy, the growth suggests a full-term delivery, significant pathological findings were not observed, and the infant was estimated to be stillborn. After the autopsy, the police investigation discovered that the mother used a stimulant during the pregnancy and shortly before the rupture of the membrane. Toxicological analysis showed 1.60mg/L of methamphetamine in the blood, strongly suggesting that the fetal death was associated with this acute intoxication. Thus far, only a few cases of infant deaths have been reported in association with methamphetamine intoxication. The present case showed the highest blood concentration of methamphetamine compared to the past infant cases with this intoxication.

The influence of circulating blood volume on blood ethanol concentrations in a rat model.

In the medicolegal field, whether a victim was under the influence of ethanol at the time of an accident or injury is an important issue. However, trauma victims may have lost a large amount of blood, or received cardiopulmonary resuscitation or infusions of fluid or blood, making it difficult to interpret the ethanol concentration at the time of sampling. We, therefore, investigated changes in ethanol elimination in a rat model in which variations in circulating blood volume were induced by means of slow hemorrhage or infusion. Animals were divided into four experimental groups: hemorrhage (H), infusion (I), hemorrhage and infusion (H&I), and control (C). All rats were administered ethanol (1 g/kg body weight) intravenously over a period of 5 minutes. Blood (group C and group I: 0.2 ml, group H and group H&I: 0.5 ml/300gBW) was collected from rats in each group every 10 minutes for 4 h. Every 10 minutes after 30 minutes to 4 h of the ethanol administration, the rats in the infusion groups were administered saline (group I: 0.5 ml/300gBW, group H&I: 1.0 ml/300gBW). The concentration of ethanol in the blood samples was determined by using head-space gas chromatography. We found that the ethanol elimination rate did not differ between the groups, indicating that variations in body fluid due to bleeding or infusion have little to no effect on blood ethanol concentrations. Blood ethanol levels obtained after a prolonged state of shock or agonal, however, may need to be cautiously interpreted.

A fatal fall associated with undiagnosed parenchymatous neurosyphilis.

A fall from a great height is often associated with altered mental status. Aside from the usual contributing factors, for example, alcohol consumption or mental illness, natural disease leading to a fatal fall is seldom identified by autopsy. The case described in this report is that of a 57-year-old man who had been clinically diagnosed with presenile Alzheimer disease and fell head first into a river from the bridge. These events were captured by a surveillance camera on the bridge; an acquaintance reported that he had previous suicidal ideation. At autopsy, the cervical spinal cord was determined to have been severely injured, and the sixth cervical vertebra was observed to have been fractured. Histological examination showed chronic meningoencephalitis including neuronal loss, perivascular cuffing, and the proliferation of microglia and astrocytes in the cerebral cortex. Serologic evaluation consisting of the nontreponemal antigen test (rapid plasma reagin [RPR]) and treponemal antibody test (Treponema pallidum latex agglutination) was positive in both cases (RPR: 18.2 RPR units, T. pallidum latex agglutination: 7718 U/mL). These findings suggested that the patient had been affected by a syphilis infection and that his suicidal behavior was associated with parenchymatous neurosyphilis.

The effect of temperature on the mechanical aspects of rigor mortis in a liquid paraffin model.

Rigor mortis is an important phenomenon to estimate the postmortem interval in forensic medicine. Rigor mortis is affected by temperature. We measured stiffness of rat muscles using a liquid paraffin model to monitor the mechanical aspects of rigor mortis at five temperatures (37, 25, 10, 5 and 0°C). At 37, 25 and 10°C, the progression of stiffness was slower in cooler conditions. At 5 and 0°C, the muscle stiffness increased immediately after the muscles were soaked in cooled liquid paraffin and then muscles gradually became rigid without going through a relaxed state. This phenomenon suggests that it is important to be careful when estimating the postmortem interval in cold seasons.

An experimental study on the macroscopic findings of ligature marks using a murine model.

Macroscopic findings of ligature marks are mainly affected by the characteristics of the ligature, the severity of external forces acting on the ligature, and the period that the neck has been pressed by the ligature. Therefore, the appearances of ligature marks formed by ligatures with the same characteristics differ depending on 2 factors: force and time. To examine which of these factors contributes more significantly to the macroscopic findings of ligature marks, a semiquantitative and experimental study using a murine model was performed. We experimentally made artificial ligature marks by hanging different sized weights using a vinyl band on dehaired legs of rats for different periods, both intravitally and postmortemly.After weights of 1, 3, and 6 kg with vinyl bands were hung on the legs of rats for 0 to 24 hours, the depths of ligature marks were semiquantitatively evaluated in 4 grades. Macroscopic examination and statistical analysis revealed that the appearance of ligature marks is not affected by whether they are formed intravitally or postmortemly but that it is equally affected by the severity of force and the duration of force application. We believe that the results of this study will be helpful to determine the characteristics of ligature and the period of hanging or strangulation time in the practice of forensic medicine.