Immunohistochemical analysis of PDGFR-α for wound age determination.

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.

Forensic significance of intracardiac expressions of Nrf2 in acute myocardial ischemia.

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.

A case of hemoperitoneum after percutaneous radiofrequency ablation in a patient with hepatocellular carcinoma.

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.

Relationship between intrathrombotic appearance of HSP27 and HSP70 and thrombus ages in a murine model of deep vein thrombosis.

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.

Essential Involvement of Neutrophil Elastase in Acute Acetaminophen Hepatotoxicity Using BALB/c Mice.

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.

Forensic application of epidermal expression of HSP27 and HSP70 for the determination of wound vitality in human compressed neck skin.

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.

Application and limitation of a biological clock-based method for estimating time of death in forensic practices.

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.

Immune Mechanisms of Pulmonary Fibrosis with Bleomycin.

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.

Macrophage polarity and wound age determination.

We investigated the dynamics of the gene expression of M1 and M2 macrophage markers during skin wound healing in mice. Expression of M1-macrophage markers, such as Il12a, Tnf, Il6, Il1b, and Nos2 was upregulated after wounding and peaked at 1 or 3 days after injury, and that of M2-macrophage markers such as Mrc1, Cd163, Ccl17, Arg, and Tgfb1, peaked at 6 days after injury. Consistent with these findings, using triple-color immunofluorescence analysis revealed that F4/80+CD80+ M1 macrophages were more abundant than F4/80+CD206+ M2 macrophages on day 3 in mouse wound specimens, and that M2 macrophages were prominently detected in day 6 wounds. For application in forensic practice, we examined macrophage polarization using human wound specimens. The average ratios of CD68+iNOS+ M1 macrophages to CD68+CD163+ M2 macrophages (M1/M2 ratios) were greater than 2.5 for the wounds aged 2-5 days. Out of 11 wounds aged 1-5 days, five samples had the M1/M2 ratios of > 3.0. These observations propose that the M1/M2 ratios of 3.0 would indicate a wound age of 1-5 days as the forensic opinion. This study showed that M1 and M2 macrophages in human skin wound might be a promising marker for wound age determination.

Forensic Application of Epidermal Ubiquitin Expression to Determination of Wound Vitality in Human Compressed Neck Skin.

Ubiquitin is a member of the heat shock protein family and is rapidly induced by various types of stimuli, including ischemic and mechanical stress. However, its significance in determining wound vitality of neck compression skin in forensic pathology remains unclear. We immunohistochemically examined the expression of ubiquitin in the neck skin samples to understand its forensic applicability in determining wound vitality. Skin samples were obtained from 53 cases of neck compression (hanging, 42 cases; strangulation, 11 cases) during forensic autopsies. Intact skin from the same individual was used as the control. Ubiquitin expression was detected in 73.9% of keratinocytes in intact skin samples, but only in 21.2% of keratinocytes in the compression regions, with statistical differences between the control and compression groups. This depletion in the case of neck compression may be caused by the impaired conversion of conjugated to free ubiquitin and failure of de novo ubiquitin synthesis. From a forensic pathological perspective, immunohistochemical examination of ubiquitin expression in the skin of the neck can be regarded as a valuable marker for diagnosing traces of antemortem compression.

A case of necrotizing fasciitis following intra-articular injections - Iatrogenic or spontaneous?

Here, we report a case of necrotizing fasciitis following intra-articular injection of hyaluronic acid. A 73-year-old female received intra-articular injections of hyaluronic acid due to arthralgia at the left shoulder and knee, and was found dead in her living room at one day. At the forensic autopsy, injection marks with bullae and erythema were found at the left shoulder and knee and liquefactive necrosis of muscle tissues was observed in the left but not right extremities. Histopathological examinations of the left upper arm and thigh revealed severe rhabdomyolysis with lots of bacterial clusters. Bacteriological examinations detected group A Streptococcus from intracardiac blood and affected muscle tissues. Postmortem biochemical analysis of blood showed escalated blood urea nitrogen (133.8 mg/dL), creatinine (4.57 mg/dL) and C-reactive protein (45.0 mg/dL). The cause of her death was diagnosed as streptococcal toxic shock syndrome (STSS). Moreover, it was suggested that the injection was inappropriately conducted and served as a portal of bacterial entry.

Fatal injury by high-pressure water jet unit - A case report.

Herein, we report a fatal case of high-pressure water-inflicted femoral injury. A male worker in his twenties was found at the construction site with significant bleeding from the left femoral region. At three hours after discovery, his death was confirmed in an emergency hospital. The deceased was noted to be 182 cm in height, 62.5 kg in weight, and postmortem rigidity strongly appeared in his whole joints. Externally, there was a large, 28-cm laceration in the left medial femoral region, wherein the subcutaneous muscle layer was drastically contused and transected, and both the femoral artery and vein were completely disrupted. This injury also penetrated into the left popliteal region similar to an impalement injury, producing a small, circular, 1.5-cm wound exit site. Moreover, two lacerations in the right anterior femoral region were presented in an inverse "U"-like shape, with injury lengths of 14 cm and 26 cm. Internally, every organ was apparently anemic, given that the water jet lance produced pressures ranging from 10,000-40,000 psi. Thus, the cause of his death was diagnosed as hemorrhagic shock secondary to femoral artery and vein disruption caused by a high-pressure water jet unit.

Forensic significance of intracardiac heme oxygenase-1 expression in acute myocardial ischemia.

Heme oxygenase-1 (HO-1), an inducible stress-response protein, exerts anti-oxidant and anti-apoptotic effects. However, its significance in forensic diagnosis of acute ischemic heart diseases (AIHD) such as myocardial infarction (MI) is still unknown. We examined the immunohistochemical expression of HO-1 in the heart samples to discuss their forensic significance to determine acute cardiac ischemia. The heart samples were obtained from 23 AIHD cases and 33 non-AIHD cases as controls. HO-1 positive signals in cardiomyocyte nuclear were detected in 78.2% of AIHD cases, however, that were detected in only 24.2% control cases with statistical difference between AIHD and non-AIHD groups. In contrast to HO-1 protein expression, there was no significant difference in the appearance of myoglobin pallor regions and leukocyte infiltration in the hearts between AIHD and non-AIHD groups. From the viewpoints of forensic pathology, intracardiac HO-1 expression would be considered a valuable marker to diagnose AIHD as the cause of death.

Intrathrombotic appearances of AQP-1 and AQP-3 in relation to thrombus age in murine deep vein thrombosis model.

Aquaporins (AQPs) are membrane-bound proteins for water transportation and are useful for diagnosing drowning and wound vitality in forensic pathology. Here, we examined intrathrombotic expression of AQP-1 and AQP-3 using deep vein thrombosis models in mice. To perform immunohistochemical analyses, we used anti-AQP-1 and anti-AQP-3 antibodies. In thrombus samples with the post-ligation intervals of 1 to 5 days, AQP-1+ areas were over 70%. At 7 days after the IVC ligation, AQP-1+ areas became less than 50%, eventually decreasing to 11% at 21 days. At 3 days after the IVC ligation, AQP-3+ cells started to appear from the peripheral area. Thereafter, the positive cell number progressively increased and reached to a peak at 10 days after the IVC ligation. When the intrathrombotic AQP-1+ area was as large as the intrathrombotic collagen area or smaller, it would indicate a thrombus age of ≥ 10 days. AQP-3+ cell number of > 30 would indicate a thrombus age of 10-14 days. Collectively, our study implied that the detection of AQP-1 and AQP-3 would be useful for the determination of thrombus age.

Complete decapitation by a self-constructed guillotine in a burned body - complex suicide or postmortem burning?

We report a suicide case of complete decapitation using a self-constructed guillotine. A 45-year-old man, whose body was severely burned, was found dead. The head was completely separated from the middle level of the neck, and a sharp blade with a steel frame was placed between the head and neck. The severance plane passed between the C4 and C5 vertebrae. Vital reactions such as hemorrhage could not be confirmed at the decapitated skin edge because the body was severely burned. Both common carotid arteries were sharply transected. Subendocardial hemorrhage was detected in the left ventricle. Only a little blood, but no soot, was detected in the respiratory tract, including the trachea and bilateral bronchi. Subarachnoid hemorrhage was noted at the edge of the cervical spinal cord. The saturation level of CO-Hb was 5.7% in the left cardiac blood, 5.9% in the right cardiac blood, and 5.8% in the peripheral blood from the femoral vein. Cervical transection was diagnosed as the cause of death. We believe that he was unintentionally burned by spread fire from an automobile after decapitation by a self-constructed guillotine.

Prevention of CaCl2-induced aortic inflammation and subsequent aneurysm formation by the CCL3-CCR5 axis.

Inflammatory mediators such as cytokines and chemokines are crucially involved in the development of abdominal aortic aneurysm (AAA). Here we report that CaCl2 application into abdominal aorta induces AAA with intra-aortic infiltration of macrophages as well as enhanced expression of chemokine (C-C motif) ligand 3 (CCL3) and MMP-9. Moreover, infiltrating macrophages express C-C chemokine receptor 5 (CCR5, a specific receptor for CCL3) and MMP-9. Both Ccl3-/- mice and Ccr5-/- but not Ccr1-/- mice exhibit exaggerated CaCl2-inducced AAA with augmented macrophage infiltration and MMP-9 expression. Similar observations are also obtained on an angiotensin II-induced AAA model. Immunoneutralization of CCL3 mimics the phenotypes observed in CaCl2-treated Ccl3-/- mice. On the contrary, CCL3 treatment attenuates CaCl2-induced AAA in both wild-type and Ccl3-/- mice. Consistently, we find that the CCL3-CCR5 axis suppresses PMA-induced enhancement of MMP-9 expression in macrophages. Thus, CCL3 can be effective to prevent the development of CaCl2-induced AAA by suppressing MMP-9 expression.

Pivotal Involvement of the CX3CL1-CX3CR1 Axis for the Recruitment of M2 Tumor-Associated Macrophages in Skin Carcinogenesis.

We previously revealed the crucial roles of a chemokine, CX3CL1, and its receptor, CX3CR1, in skin wound healing. Although repeated wounds frequently develop into skin cancer, the roles of CX3CL1 in skin carcinogenesis remain elusive. Here, we proved that CX3CL1 protein expression and CX3CR1+ macrophages were observed in human skin cancer tissues. Similarly, we observed the enhancement of CX3CL1 expression and the abundant accumulation of CX3CR1+ tumor-associated macrophages with M2-like phenotypes in the skin carcinogenesis process induced by the combined treatment with 7,12-dimethylbenz[a]anthracene and 12-O-tetradecanoylphorbol-13-acetate. In this mouse skin carcinogenesis process, CX3CR1+ tumor-associated macrophages exhibited M2-like phenotypes with the expression of Wnt3a and angiogenic molecules including VEGF and matrix metalloproteinase 9. Compared with wild-type mice, CX3CR1-deficient mice showed fewer numbers of skin tumors with a lower incidence. Concomitantly, M2-macrophage numbers and neovascularization were reduced with the depressed expression of angiogenic factors and Wnt3a. Thus, the CX3CL1-CX3CR1 axis can crucially contribute to skin carcinogenesis by regulating the accumulation and functions of tumor-associated macrophages. Thus, this axis can be a good target for preventing and/or treating skin cancers.

Forensic pathological study on temporal appearance of dendritic cells in skin wounds.

Dendritic cells (DCs) can essentially contribute to innate and adaptive immune system in various organs. A double-color immunofluorescence analysis was carried out with anti-CD11c and -HLA-DRα antibodies to detect DCs in 53 skin wounds (their postinfliction intervals: group I, 0-3 days; group II, 4-7 days; group III, 9-14 days; and group IV, 17-21 days). CD11c+HLA-DRα+ DCs were first observed in skin wounds with postinfliction intervals of 3 days, and the DC numbers were found to be elevated in skin wounds with the subsequent increase in postinfliction intervals. Semi-quantitative morphometric analyses showed that the DC number was the highest in the 12-day-old wound. More than 50 DCs were present in 8 of 10 samples (80%) in group II and 14 of 16 samples (87.5%) in group III, and there was no difference between the two groups. Thus, the presence of DCs in a skin wound was possibly estimated as postinfliction intervals of at least 3 days. Furthermore, when a skin wound contained > 50 DCs, its age would be judged as 4-14 days. Collectively, the appearance of DCs in human skin wounds may provide useful information in determining the age of a wound.

A case of complex suicide due to acute nicotine intoxication caused by cigarette ingestion.

This paper presents an unusual complex suicide case that died of nicotine addiction. The deceased was a 40-year-old male who was found lying dead on the floor in his room. In external findings, many incision wounds on his forearms and skin discoloration with epidermolysis on his cervical region could be seen. In the room, a blood-stained scissors and electric cord hanged on the exercise bike were found. Moreover, nine cigarette residues which were only the filter part and empty bottle of coffee were found on his side. At autopsy, we found that those injuries were not serious enough to lead him to the death. Toxicologically, caffeine, nicotine, cotinine, mirtazapine, and olanzapine could be detected, and the concentrations of nicotine were 3.740, 2.140, 3.100, and 451.100 µg/ml in cardiac blood, peripheral blood, urine, and stomach contents, respectively. These concentrations were evaluated as the fatal levels, and the cause of his death was diagnosed as acute nicotine intoxication.

The application of autophagy to thrombus age estimation in murine deep vein thrombosis model.

We immunohistochemically examined the intrathrombotic dynamics of autophagy during thrombogenesis using murine deep vein thrombosis (DVT) models. To perform the immunohistochemical analyses, we used anti-LC3 antibody and anti-p62 antibody for detecting the intrathrombotic autophagic functions. We estimated dynamics of the intrathrombotic autophagy as LC3+ cell number (×1000, five fields) with the thrombus ages (each group n = 5). The number of LC3+ cells was once decreased at 3 days, and then increased until 10 days. On the contrary, the number of p62+ cells progressively increased until 10 days after the inferior vena cava (IVC) ligation, and then gradually decreased. Especially, in all of thrombus samples with the postligation intervals of 5-10 days, both numbers were larger than 10. Subsequently, we compared the number of LC3+ cells to that of p62+ cells. Although, at 1 day after the IVC ligation, LC3+ cell number significantly exceeded p62+ cell number, the former was significantly or relatively less than the latter at 3 days or more after the IVC ligation. Thus, positive cells of > 10 in both LC3 and p62 indicated the thrombus age of 5-10 days. Upon comparison of immunopositive cells in LC3 and p62, the p62/LC3 ratio was > 1.0 in 29 out of 30 thrombus samples aged 3-21 days, and all of 1-day-old thrombus had the p62/LC3 ratio of < 0.5. Thus, the ratio of > 1.0 and that of < 0.5 could indicate thrombus age of 3 days or more and that of 1 day, respectively. Collectively, our study implied that the detection of autophagy-related molecules such as LC3 and p62 would be useful for the determination of thrombus age.