Determining whether ligature marks represent antemortem or postmortem injuries is a critical issue in forensic practice because this distinction directly influences the reconstruction of perimortem events. Consequently, assessing the vital reaction of neck skin plays an essential role in evaluating the viability of compression-related injuries. Cathelicidin antimicrobial peptide (CAMP), a multifunctional host-defense peptide involved in inflammation, immune cell recruitment, and wound repair, may serve as a reliable molecular marker for wound vitality. In this study, we examined CAMP expression in 40 ligature mark samples (32 samples of hanging and 8 samples of ligature/manual strangulation) obtained during forensic autopsies, along with matched intact skin controls, all with postmortem intervals of ≤ 3 days. Immunohistochemistry revealed strong CAMP expression in epidermal keratinocytes and moderate expression in dermal cells at compression sites, whereas control skin showed only faint or absent staining. Morphometric analysis demonstrated that the ratio of CAMP‑positive keratinocytes and the number of CAMP-positive dermal cells were significantly higher in compressed skin than in controls, independent of age, sex or postmortem interval. Moreover, neither ligature type nor mode of neck compression also had no influence on CAMP expression in the keratinocytes or dermal cells. These findings indicate that CAMP expression reflects a biological response to antemortem neck compression and may provide an objective molecular marker for assessing wound vitality in forensic pathology. Furthermore, combining CAMP with other established biomarkers may enhance diagnostic reliability when evaluating antemortem neck compression injuries.

Acute ischemic heart disease (AIHD) is a major cause of sudden cardiac death, yet postmortem diagnosis is difficult, particularly in early-phase ischemic injury or decomposed bodies. We investigated the diagnostic value of two molecular biomarkers—8-hydroxy-2′-deoxyguanosine (8-OHdG), indicating oxidative DNA damage, and N-terminal pro-brain natriuretic peptide (NT-proBNP), reflecting cardiac wall stress—in 67 human forensic autopsy cases (33 AIHD, 34 non-AIHD). Immunohistochemistry revealed significantly greater and more diffuse nuclear 8-OHdG expression in AIHD cardiomyocytes compared with controls. Postmortem blood NT-proBNP levels were also significantly higher in AIHD cases (2389.1 ± 499.6 pg/mL) than in non-AIHD cases (896.1 ± 190.1 pg/mL). No significant correlations were found between 8-OHdG expression and NT-proBNP levels, contraction band necrosis, postmortem interval, age, or sex, suggesting that these markers reflect distinct pathological processes—oxidative injury and hemodynamic stress. Both markers demonstrated postmortem stability, and their combined evaluation improved diagnostic confidence in cases with inconclusive histology. This dual-biomarker approach may enhance the accuracy of AIHD diagnosis in forensic practice and provide complementary insights into the molecular mechanisms underlying sudden cardiac death.

In the original publication [...].

We report a case of fatal acute butane poisoning in a woman in her 80 s, who was found in a bathtub filled with butane gas. Five artificially punctured liquefied petroleum gas (LPG) cartridges were discovered within the bathtub. Forensic autopsy revealed no significant traumatic injuries or pathological findings sufficient to explain the cause of death. Toxicological analysis identified butane and diphenhydramine (DPH) in the blood, urine, and various organs. The peripheral blood concentrations of butane and DPH were 2.95 μ g/ml and 3.56 μ g/ml, respectively. While the DPH concentration was within the toxic range, it did not reach fatal levels independently. Given that the urinary DPH concentration (0.25 μ g/ml) was approximately 1/14th of the blood concentration, it was concluded that death occurred due to butane toxicity during the absorptive phase of DPH. Based on the toxicological findings and the scene circumstances, the cause of death was determined to be acute butane poisoning.

CX3CL1 and its unique receptor, CX3CR1, are leukocyte migration factors and are involved in the pathogenesis and progression of many inflammatory diseases and malignancies. The CX3CL1-CX3CR1 axis induces a variety of responses, including cell proliferation, migration, invasion, and apoptosis resistance. CX3CL1 is a transmembrane protein, and proteolysis generates a soluble form. The membrane and soluble forms of CX3CL1 exhibit different functions, but both bind to the chemokine receptor CX3CR1. The CX3CL1-CX3CR1 axis is a chemokine system that has attracted attention not only as a therapeutic target but also as a potentially useful diagnostic and prognostic marker for disease. Many studies have reported that the CX3CL1-CX3CR1 axis is involved in disease progression, but more recently there are scattered reports suggesting that it is involved in disease suppression. In this article, we summarize the latest findings on the pathophysiological role of the CX3CL1-CX3CR1 axis, with a particular focus on renal disease, cardiovascular disease, and cancer.

Lysosomal stress due to the accumulation of nucleic acids (NAs) activates endosomal TLRs in macrophages. Here, we show that lysosomal RNA stress, caused by the lack of RNase T2, induces macrophage accumulation in multiple organs such as the spleen and liver through TLR13 activation by microbiota-derived ribosomal RNAs. TLR13 triggered emergency myelopoiesis, increasing the number of myeloid progenitors in the bone marrow and spleen. Splenic macrophages continued to proliferate and mature into macrophages expressing the anti-inflammatory cytokine IL-10. In the liver, TLR13 activated monocytes/macrophages to proliferate and mature into monocyte-derived KCs (moKCs), in which, the liver X receptor (LXR) was activated. In accumulated moKCs, tissue clearance genes such as MerTK, AXL, and apoptosis inhibitor of macrophage (AIM) were highly expressed, while TLR-dependent production of proinflammatory cytokines was impaired. Consequently, Rnaset2-/- mice were resistant to acute liver injuries elicited by acetaminophen (APAP) and LPS with D-galactosamine. These findings suggest that TLR13 activated by lysosomal RNA stress promotes the replenishment of tissue-protective Kupffer cells.

This retrospective study evaluated 637 forensic autopsy cases of solitary deaths (kodoku-shi in Japanese) and clarified the current status of solitary deaths from the viewpoint of forensic medicine. Of the 637 cases of solitary death, 471 were men and 166 were women, indicating that solitary death predominantly occurred in men. This tendency increased from the age of 40 years in men to 60 years in women. Among these, 349 and 199 were natural and external deaths, respectively. Ischemic heart disease and fire-related fatalities were the most common causes of natural and external death, respectively. Suicidal deaths were more frequent among women than men. We found two peaks of postmortem interval until finding (PMI-f): <1 day (182 cases, 28.6 %) and 7 days to < 1 month (164 cases, 25.7 %). The PMI-f was significantly shorter in women than in men. The PMI-f of external death cases was significantly shorter than that of natural death cases. Kushimoto and Shingu, located in Southern Japan (Kinan region), had a high solitary death rate in forensic autopsy cases because of the high aging rate and high rate of individuals in single-person households aged ≥ 65 years. Few cases of solitary deaths in the Kinan region (non-urban area) were welfare recipients, and 23 of the 36 welfare recipients lived in Wakayama City, indicating that the economic state contributed more to the occurrence of solitary deaths in Wakayama City (urban area). We identified several risk factors and regional characteristics of solitary deaths. Our observations could contribute to administrative welfare measures for the prevention of solitary deaths.

Japanese spotted fever (JSF) is potentially fatal infection transmitted by tick bites which vectors Rickettsia (R.) japonica. Since JSF was first described in 1984, the incidence has gradually been increased. We experienced a case of JSF of fatal outcome. A female in 70 ' s was found dead on her bed, whose house was so called 'hoarding house' filled with many waists and unused items. The following day, the autopsy was performed. As representative symptom of external findings, skin rashes were seen on the trunk and extremities, and there were tick-bite eschars on the left upper arm. Internal findings showed no specific findings in each organ. Histopathological examination demonstrated massive inflammatory cell infiltrates mainly consisted of neutrophils in the dermis beneath the external eschar. Furthermore, destruction of glomeruli in kidney with microhemorrhage from mesangial regions was observed. The numerous inflammatory infiltrates were also observed in pulmonary interstitium, which were accompanied with histopathologic features of vasculitis. Biochemical examination showed severe systemic inflammation as monitored by elevated CRP of 16 mg/dL and renal dysfunction by BUN of 171.2 mg/dL and creatinine of 6.07 mg/dL. Subsequently polymerase chain reaction revealed specifically amplified signals for R. japonica from the samples of tick-bites eschar and blood. Thus, we diagnosed her cause of death as JSF which had been occurred multiorgan failure such as acute renal failure and possibly acute respiratory failure. (224 terms)

Matrix metalloproteinase-9 (MMP-9) is involved in tissue remodeling and in skin wound healing. The present study focuses on the MMP-9 expression in epidermal wound healing within 1 h after injury, to test whether MMP-9 can be used to estimate the time of injury in forensic practice. A sample consisting of 5 individuals undergoing surgery was analyzed. With the consent of the patients, sections of skin were removed from the surgical wound at predefined time intervals. For each subject, 8 sections were taken, one for each time interval defined at 0 ‘- 1’ − 3 ‘- 5’ − 10 ‘- 15’ − 30 ‘- 60’ minutes. The specimens were immunostained with MMP-9, and the number of positively stained cells was examined. The number of positively stained cells showed an increasing trend as a function of time. Less than 30 positively stained cells were found in all cases within 3 min. At the post-infliction time of 5 min, the number of positively stained cells exceeded 30 in 3 out of 5 cases. The number of MMP-positive cells exceeded 40 in all cases in over 10 min. In the light of these results, the count of MMP-9 positive cells might be a useful marker in the wound-age estimation within 1 h in forensic setting. More research is required to collect more samples and to compare samples from the hyperacute phase with those from several days after injury.

When exposed to oxidative and electrophilic stress, a protective antioxidant response is initiated by nuclear factor erythroid 2-related factor 2 (Nrf2). However, the extent of its importance in the forensic diagnosis of acute ischemic heart diseases (AIHD), such as myocardial infarction (MI), remains uncertain. On the other hand, immunohistochemical analyses of fibronectin (FN) and the terminal complement complex (C5b-9) prove valuable in identifying myocardial ischemia that precedes necrosis during the postmortem diagnosis of sudden cardiac death (SCD). In this study, we investigated the immunohistochemical levels of Nrf2, FN, and C5b-9 in human cardiac samples to explore their forensic relevance for the identification of acute cardiac ischemia. Heart samples were obtained from 25 AIHD cases and 39 non-AIHD cases as controls. Nrf2 was localized in the nuclei of cardiomyocytes, while FN and C5b-9 were detected in the myocardial cytoplasm. The number of intranuclear Nrf2 positive signals in cardiomyocytes increased in AIHD cases compared to control cases. Additionally, the grading of positive portions of cardiac FN and C5b-9 in the myocardium was also significantly enhanced in AIHD, compared to controls. Collectively, these results indicate that the immunohistochemical investigation of Nrf2 combined with FN, and/or C5b-9 holds the potential for identifying early-stage myocardial ischemic lesions in cases of SCD.

Immunohistochemical analysis of platelet-derived growth factor receptor-α (PDGFR-α) was performed on human skin wounds obtained from forensic autopsy cases. Thirty human skin wounds were collected at different post-infliction intervals as follows: Group I, 4 h to 3 days (n = 16); Group II, 4 to 7 days (n = 7); Group III, 9 to 10 days (n = 3); and Group IV, 14 to 20 days (n = 4). Immunopositive reactions for PDGFR-α were not observed in the uninjured human skin specimens. In a semi-quantitative morphometrical analysis, the number of PDGFR-α-positive cells was observed increased in Group II, with the average number of PDGFR-α-positive cells being the highest in Group II. Additionally, in Group II, all specimens showed PDGFR-α-positive cells, with an average number of > 200 cells in five fields of view, suggesting a wound age of 4 to 7 days. Taken together, the immunohistochemical detection of PDGFR-α in human skin wounds can be a useful tool for wound age determination.

Cisplatin is an effective chemotherapeutic agent widely used for the treatment of various solid tumors. However, cisplatin has an important limitation in its use; currently, there is no method to ameliorate cisplatin-induced acute kidney injury (AKI). Thrombomodulin (TM) is well known not only for its role as a cofactor in the clinically important natural anticoagulation pathway but also for its anti-inflammatory properties. Here, we investigated the effects of TM in cisplatin-induced AKI. In mice intraperitoneally injected with 15 mg/kg cisplatin, TM (10 mg/kg) or PBS was administered intravenously at 24 h after cisplatin injection. TM significantly attenuated cisplatin-induced nephrotoxicity with the suppressed elevation of blood urea nitrogen and serum creatinine, and reduced histological damages. Actually, TM treatment significantly alleviated oxidative stress-induced apoptosis by reducing reactive oxygen species (ROS) levels in cisplatin-treated renal proximal tubular epithelial cells (RPTECs) in vitro. Furthermore, TM clarified cisplatin-induced apoptosis by reducing caspase-3 levels. In addition, TM attenuated the endoplasmic reticulum (ER) stress signaling pathway in both renal tissues and RPTECs to protect the kidneys from cisplatin-induced AKI. These findings suggest that TM is a potential protectant against cisplatin-induced nephrotoxicity through suppressing ROS generation and ER stress in response to cisplatin.

Heat shock proteins (HSPs) are molecular chaperones whose primary function is cytoprotection, supporting cell survival under (sub) lethal conditions. They have been implicated in various diseases such as inflammatory diseases and cancer due to their cytoprotective and immunomodulatory effects, and their biological mechanisms have been studied. Central family members include, HSP27, which is induced by various stimuli such as heat shock, hypoxia, hyperoxia, ultraviolet exposure, and nutritional deficiency, and HSP70, which is homeostatically expressed in many organs such as the gastrointestinal tract and has anti-cell death and anti-inflammatory effects. In this study, HSP27 and HSP70 were investigated during thrombus formation and dissolution in a deep vein thrombosis model by immunohistochemistry to determine their involvement in this process and whether their expression could be used as a forensic marker. In the process of thrombus formation and lysis, HSP27 and HSP70 were found to be expressed by immunohistochemical analysis. The role of inhibitors of HSP27 and HSP70 in the pathogenesis of thrombosis in mice was also investigated. When HSP27 or HSP70 inhibitors were administered, thrombi were significantly smaller than in the control group on day 5 after inferior vena cava ligation, indicating pro-thrombotic effects HSP27 and HSP70. If HSP27- or HSP70-positive cells were clearly visible and easily identifiable in the thrombus sections, the thrombus was presumed to be more than 10 days old. Thus, the detection of intrathrombotic HSP27 and HSP70 could forensically provide useful information for the estimation of thrombus ages. Collectively, our study implied that both HSP27 and HSP70 might be molecular targets for thrombus therapy and that the detection of HSP-related molecules such as HSP27 and HSP70 could be useful for the determination of thrombus ages.

Aquaporins (AQPs) are a family of water channel proteins that primarily elicit the basic functions of water transport and osmotic homeostasis. To date, at least 17 mammalian AQPs have been identified, AQP-0 to -12 have been found in higher orders including human, and AQP-13 to -16 have been described in older lineages. Moreover, these proteins have recently been shown to regulate many biological processes through unique activities, such as cell proliferation, migration, apoptosis, and mitochondrial metabolism. Several studies have focused on the involvement of AQPs in cell biology aspect, showing that they are involved in a variety of physiological processes and pathophysiological conditions. Furthermore, in the field of forensic medicine, studies on whether AQPs can be a useful marker for diagnosing various causes of death have been conducted using autopsy samples and animal experiments, which have produced interesting results. Herein, we review certain observations regarding AQPs and discuss their potential to contribute to the future practice of forensic research.

Intense neutrophil infiltration into the liver is a characteristic of acetaminophen-induced acute liver injury. Neutrophil elastase is released by neutrophils during inflammation. To elucidate the involvement of neutrophil elastase in acetaminophen-induced liver injury, we investigated the efficacy of a potent and specific neutrophil elastase inhibitor, sivelestat, in mice with acetaminophen-induced acute liver injury. Intraperitoneal administration of 750 mg/kg of acetaminophen caused severe liver damage, such as elevated serum transaminase levels, centrilobular hepatic necrosis, and neutrophil infiltration, with approximately 50% mortality in BALB/c mice within 48 h of administration. However, in mice treated with sivelestat 30 min after the acetaminophen challenge, all mice survived, with reduced serum transaminase elevation and diminished hepatic necrosis. In addition, mice treated with sivelestat had reduced NOS-II expression and hepatic neutrophil infiltration after the acetaminophen challenge. Furthermore, treatment with sivelestat at 3 h after the acetaminophen challenge significantly improved survival. These findings indicate a new clinical application for sivelestat in the treatment of acetaminophen-induced liver failure through mechanisms involving the regulation of neutrophil migration and NO production.

Fibrosis and structural remodeling of the lung tissue can significantly impair lung function, often with fatal consequences. The etiology of pulmonary fibrosis (PF) is diverse and includes different triggers such as allergens, chemicals, radiation, and environmental particles. However, the cause of idiopathic PF (IPF), one of the most common forms of PF, remains unknown. Experimental models have been developed to study the mechanisms of PF, and the murine bleomycin (BLM) model has received the most attention. Epithelial injury, inflammation, epithelial–mesenchymal transition (EMT), myofibroblast activation, and repeated tissue injury are important initiators of fibrosis. In this review, we examined the common mechanisms of lung wound-healing responses after BLM-induced lung injury as well as the pathogenesis of the most common PF. A three-stage model of wound repair involving injury, inflammation, and repair is outlined. Dysregulation of one or more of these three phases has been reported in many cases of PF. We reviewed the literature investigating PF pathogenesis, and the role of cytokines, chemokines, growth factors, and matrix feeding in an animal model of BLM-induced PF.

Estimating the age and vitality of human skin wounds is essential in forensic practice, and the use of immunohistochemical parameters in this regard remains a challenge. Heat shock proteins (HSPs) are evolutionarily conserved universal proteins that protect biological systems from various types of stress. However, its importance in forensic pathology for determining wound activation in neck compression skin remains unclear. The expression of HSP27 and HSP70 in neck skin samples was immunohistochemically examined to understand its forensic applicability in determining wound vitality. Skin samples were obtained from 45 cases of neck compression (hanging, 32 cases; strangulation, 10 cases; manual strangulation, 2 cases; other, 1 case) during forensic autopsies; intact skin from the same individual was used as a control. HSP27 expression was detected in 17.4% of keratinocytes in the intact skin samples. In the compressed region, the frequency of HSP27 expression in keratinocytes was 75.8%, which was significantly higher than that in intact skin. Similarly, HSP70 expression was 24.8% in intact skin samples and 81.9% in compressed skin samples, significantly higher in compressed skin than in intact skin samples. This increase in case compression cases may be due to the cell defence role of HSPs. From a forensic pathology perspective, the immunohistochemical examination of HSP27 and HSP70 expression in neck skin could be considered a valuable marker for diagnosing traces of antemortem compression.

Estimating time of death is one of the most important problems in forensics. Here, we evaluated the applicability, limitations and reliability of the developed biological clock-based method. We analyzed the expression of the clock genes, BMAL1 and NR1D1, in 318 dead hearts with defined time of death by real-time RT-PCR. For estimating the time of death, we chose two parameters, the NR1D1/BMAL1 ratio and BMAL1/NR1D1 ratio for morning and evening deaths, respectively. The NR1D1/BMAL1 ratio was significantly higher in morning deaths and the BMAL1/NR1D1 ratio was significantly higher in evening deaths. Sex, age, postmortem interval, and most causes of death had no significant effect on the two parameters, except for infants and the elderly, and severe brain injury. Although our method may not work in all cases, our method is useful for forensic practice in that it complements classical methods that are strongly influenced by the environment in which the corpse is placed. However, this method should be applied with caution in infants, the elderly, and patients with severe brain injury.

We report a case of hemoperitoneum after percutaneous radiofrequency ablation in a patient with hepatocellular carcinoma. A 60-year-old female was hospitalized for the treatment of thrombasthenia and cirrhosis caused by chronic Hepatitis C, and computed tomography revealed hepatocellular carcinoma, which was treated by percutaneous radiofrequency ablation. After the ablation, hemoperitoneum was suspected because of the low hemoglobin level with abdominal pain. Approximately 6 h after the ablation treatment, the patient suddenly fell into a shock state and died. In this case, medical treatment-related death including malpractice was suspected, and forensic autopsy was performed. The abdominal cavity contained 910 mL of dark red fluid blood and 210 g of soft hemocoagula. Moreover, several puncture marks were observed on the liver surface and diaphragm, and there was no clear damage to the main arteries and veins. Considering the macroscopic and microscopic findings, the cause of death was assumed as hemorrhagic shock due to the hemoperitoneum caused by the damage to the liver by radiofrequency ablation. It is important to consider all the indications and adverse effects of radiofrequency ablation.