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.

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.

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.

Whole Mitochondrial DNA Sequencing Using Fecal Samples from Domestic Dogs.

Medical care for domestic dogs is now respected worldwide as being at a similar level to that of humans. We previously established a test method to determine whole mitochondrial DNA (mtDNA) using oral mucosal DNA that may be useful for medical care and welfare. However, the sample types tested in dogs are not limited to those obtained from the oral mucosa. Therefore, in the present study, we attempted to establish a test method to determine whole mtDNA sequences using feces, which represents the least invasive specimen. Two Japanese domestic dogs were used in the present study. DNA was extracted from approximately 100 mg of fresh feces from each dog, and PCRs were performed using four primer pairs that can amplify whole mtDNA. Following PCR, amplicons were pooled to create a DNA library using an experimental robot with an original program. Data were then acquired via NGS and data analysis was performed. The results showed that the whole mtDNA sequence of the two dogs was determined with high accuracy. Our results suggest that feces can be adapted for mitochondrial disease and individual identification testing and could serve as a useful testing method for the future medical care and welfare of domestic dogs.

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.