Association of a single nucleotide polymorphism (rs27434) in the ERAP1 gene with plural tissue weight.

Our study was designed to examine the correlation between single nucleotide polymorphism (SNP) in the endoplasmic reticulum aminopeptidase 1 (ERAP1) gene, specifically focusing on rs27434, and plural tissue weight. We conducted this investigation using autopsy samples from the Japanese population. Blood samples were collected from 178 Japanese subjects who had undergone autopsies in Shimane Prefecture. Genomic DNA was subsequently extracted from these samples. SNP (rs27434, G＞A substitution) was analyzed by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analysis. In the present study, rs27434 exhibited a statistically significant association with brain weight (g) in both female and male individuals. Among males, rs27434 displayed significant relationships with liver weight (g), and body surface area (m2). In females, rs27434 was significantly related to the length of the appendix. Across both genders, individuals with GA and AA genotypes tended to exhibit higher levels in these respective measurements compared to those with the GG genotype. These results suggest that genetic variant of ERAP1 gene may influence the weight of the organs. To the best of our knowledge, this is the first study investigating the interaction between the association of rs27434 in the ERAP1 gene and data routinely measured at autopsy, such as tissue weight. However, conducting further investigations with larger population samples could provide more comprehensive insights to clarify this issue.

Thallium - poisoner's poison: An overview and review of current knowledge on the toxicological effects and mechanisms.

Thallium (Tl) is one of the most toxic metals and its historic use in homicides has led it to be known as "the poisoner's poison." This review summarizes the methods for identifying Tl and determining its concentrations in biological samples in recently reported poisoning cases, as well as the toxicokinetics, toxicological effects, toxicity mechanisms, and detoxication methods of Tl. Recent findings regarding Tl neurotoxicological pathways and toxicological effects of Tl during pregnancy are also presented. Confirmation of elevated Tl concentrations in blood, urine, or hair is indispensable for diagnosing Tl poisoning. The kidneys show the highest Tl concentration within 24 h after ingestion, while the brain shows the highest concentration thereafter. Tl has a very slow excretion rate due to its large distribution volume. Following acute exposure, gastrointestinal symptoms are observed at an early stage, and neurological dysfunction is observed later: Tl causes the most severe damage in the central nervous system. Alopecia and Mees' lines in the nails are observed within 1 month after Tl poisoning. The toxicological mechanism of Tl is considered to be interference of vital potassium-dependent processes with Tl+ because its ionic radius is similar to that of K+, as well as inhibition of enzyme reactions by the binding of Tl to -SH groups, which disturbs vital metabolic processes. Tl toxicity is also related to reactive oxygen species generation and mitochondrial dysfunction. Prussian blue is the most effective antidote, and metallothionein alone or in combination with Prussian blue was recently reported to have cytoprotective effects after Tl exposure. Because Tl poisoning cases are still reported, early determination of Tl in biological samples and treatment with an antidote are essential.

Review of Zinc Oxide Nanoparticles: Toxicokinetics, Tissue Distribution for Various Exposure Routes, Toxicological Effects, Toxicity Mechanism in Mammals, and an Approach for Toxicity Reduction.

Zinc oxide (ZnO) nanoparticles (NPs) are widely used as a sunscreen, antibacterial agent, dietary supplement, food additive, and semiconductor material. This review summarizes the biological fate following various exposure routes, toxicological effects, and toxicity mechanism of ZnO NPs in mammals. Furthermore, an approach to reduce the toxicity and biomedical applications of ZnO NPs are discussed. ZnO NPs are mainly absorbed as Zn2+ and partially as particles. Regardless of exposure route, elevated Zn concentration in the liver, kidney, lungs, and spleen are observed following ZnO NP exposure, and these are the target organs for ZnO NPs. The liver is the main organ responsible for ZnO NP metabolism and the NPs are mainly excreted in feces and partly in urine. ZnO NPs induce liver damage (oral, intraperitoneal, intravenous, and intratracheal exposure), kidney damage (oral, intraperitoneal, and intravenous exposure) and lung injury (airway exposure). Reactive oxygen species (ROS) generation and induction of oxidative stress may be a major toxicological mechanism for ZnO NPs. ROS are generated by both excess Zn ion release and the particulate effect resulting from the semiconductor or electronic properties of ZnO NPs. ZnO NP toxicity can be reduced by coating their surface with silica, which prevents Zn2+ release and ROS generation. Due to their superior characteristics, ZnO NPs are expected to be used for biomedical applications, such as bioimaging, drug delivery, and anticancer agents, and surface coatings and modification will expand the biomedical applications of ZnO NPs further.

Plasma cell-free DNA in patients with acute promyelocytic leukemia treated with arsenic trioxide.

BACKGROUND: Cell-free DNA (cfDNA) is free DNA found in circulating blood that originates from apoptosis or necrosis, and elevated cfDNA concentrations have been reported in cancers and other diseases. METHODS: In this study, the concentrations and fragment distributions of plasma cfDNA were preliminary investigated in elderly (n = 1) and pediatric (n = 1) patients with acute promyelocytic leukemia (APL) treated with arsenic trioxide (ATO). RESULTS: A slight increase in cfDNA concentrations was observed in the APL patients compared with healthy controls. The change in plasma cfDNA concentrations corresponded to the change in plasma arsenic concentrations during ATO treatment. The fragment distribution pattern did not differ before and during treatment. Three ladder fragments were observed in part of the cfDNA in the second consolidation therapy in an elderly APL patient and the first consolidation therapy of a pediatric APL patient, while two fragments were observed in all other treatment periods. Moreover, APL-related gene mutations were successfully genotyped from plasma cfDNA by using polymerase chain reaction-based methods and these results are consistent with those from leukocytes. CONCLUSION: This study is the first to report the concentrations and fragment patterns of cfDNA from APL patients treated with ATO. The results suggested that plasma cfDNA concentration in APL patients increased with ATO treatment and that cfDNA is released mainly via neutrophil extracellular traps (and/or necrosis) in addition to apoptosis. To confirm whether cfDNA concentrations and fragment patterns can be used as a biomarker for APL treated with ATO, further accumulative data are needed.

Systemic Administration of Porphyromonas Gingivalis Lipopolysaccharide Induces Glial Activation and Depressive-Like Behavior in Rats.

BACKGROUND: Periodontitis is one of the most common chronic inflammatory disorders in adults. Although clinical studies have suggested a causal relationship between periodontitis and major depression (MD), the biological mechanisms by which periodontitis instigates MD are unknown. We investigated whether a systemic administration of lipopolysaccharide (LPS) from Porphyromonas gingivalis (Pg), a major Gram-negative pathogen of periodontitis, causes depressive-like behavior and glial activation in the hippocampus and the prefrontal cortex (PFC), which are MD-related brain regions. MATERIALS AND METHODS: Eight-week-old male Sprague Dawley rats were randomly divided into a behavioral test group and an immunohistochemistry group. The rats in each group were further assigned to the sham injection (saline) and Porphyromonas gingivalis-lipopolysaccharide (Pg-LPS) injection protocols. The rats received an intraperitoneal injection of saline or Pg-LPS with gradually increasing doses (day 1: 0.5, day 2: 0.5, day 3: 0.75, day 4: 0.75, day 5: 1.0, day 6: 1.0, and day 7: 1.0 mg/kg of body weight) for seven consecutive days. After the systemic administration, the behavior test group underwent the forced swimming test (FST) and Y-maze test. For the immunohistochemistry group, we quantified the immunoreactivity for microglial Iba-1 (ionized calcium-binding adapter molecule 1) and astrocytic glial fibrillary acidic protein (GFAP) in the hippocampus (dentate gyrus [DG], cornu ammonis [CA1 and CA3]) and PFC (prelimbic [PrL] and the infralimbic [IL]) areas. RESULTS: The FST immobility time in the Pg-LPS group was significantly longer than that in the sham group. In the Y-maze test, a significant decline in spontaneous alternation behavior was observed in the Pg-LPS group compared to the sham group. The peripheral administration of Pg-LPS significantly increased the immunoreactivity for Iba-1 in the CA3 and PrL. Pg-LPS injection significantly increased the immunoreactivity for GFAP in the DG, CA1, and CA3. CONCLUSIONS: The major result of this study is that a repeated systemic administration of Pg-LPS caused depressive-like behavior and both microglial and astrocytic activation in rats. This finding may comprise biological evidence of a causal relationship between periodontitis and MD.

Cell-free DNA Release in the Plasma of Patients with Cardiac Disease is Associated with Cell Death Processes.

Cell-free DNA (cfDNA) is released into the plasma of patients with cardiac disease. Here, the source and mechanism of plasma cfDNA release in patients with myocardial infarction (MI) and other cardiac diseases (n = 59) were investigated. Plasma levels of various markers including M30 (apoptosis), M65 (apoptosis and necrosis), cyclophilin A (CyPA) (necrosis), and myeloperoxidase (MPO) (neutrophil activation) were assayed. The plasma cfDNA concentrations in MI and other cardiac diseases were significantly higher than that in the healthy control subjects. Significant differences were not observed among the cardiac disease patients (MI and other cardiac diseases) and healthy control subjects in M30, M65, and CyPA levels. In contrast,the MPO levels were significantly elevated in cardiac disease patients when compared to control groups, and MPO levels in MI patients were significantly higher than other cardiac diseases patients. These results suggest that cfDNA is mainly released by neutrophils via NETosis in addition to apoptosis except for epithelial apoptosis in patients with cardiac disease and the degree is greater in MI patients. The results from this study provide basic information for diagnosis marker of MI.

Comparison of serum cell-free DNA between postmortem and living samples.

Cell-free DNA (cfDNA) originates from apoptotic and/or necrotic cells. Few reports are available that examine cfDNA from postmortem samples. Therefore, this study investigated differences between postmortem and biogenic subjects in concentration and fragment distribution of serum cfDNA. We also clarified features of serum cfDNA in postmortem subjects. The results revealed that postmortem subjects had significantly higher cfDNA concentrations than healthy controls and patients with cardiac disease. Serum cfDNA concentrations increased slightly with postmortem interval in subjects who died of asphyxia, and they were slightly higher in subjects who died from internal vs. external causes. Microchip electrophoresis of serum cfDNA revealed a fragment larger than 10,000 bp in only two postmortem subjects; we speculate that the fragment may have originated from necrotic cells. A relatively high concentration of one 150-200 bp fragment was characteristic of postmortem samples. This fragment may have been derived from apoptosis or other processes. We also observed ladder fragments in some subjects who died from external causes. Although additional research is needed for verification, serum cfDNA concentrations and fragment patterns possibly be used as a tool to estimate postmortem intervals and cause of death.

The indicators associated with increasing suicide trends: Need for harmony in discussing suicide in legal medicine and other fields.

Each year in Japan from 1990 to 1997, approx. 21,000-24,000 individuals committed suicide. In 1998, the number of suicides increased to >30,000, and a trend of high suicide numbers then persisted for >10 years. Although Japan's annual number of suicides has recently been decreasing, it remains among the highest worldwide. Herein, we assessed the annual suicide data (numbers and rates) related to three economic and life indicators: (1) the difference between actual income and consumer spending of one average month per year in one household, (2) the annual difference between exports and imports, and (3) the annual total debt determined by statistical analyses for both sexes/males/females during the 40-year period from 1979 to 2018 in Japan. Our findings indicated that [1] total debt may be associated with both the number of suicides and the suicide rate for both sexes, for males, and for females, and [2] the difference between actual income and consumer spending may be associated with both the number of suicides and the suicide rate only in females. These findings revealed factors that are clearly suicide-related, and it is necessary to design suicide prevention strategies based on the factors. Relevant public and private entities should become aware of the involvement of both debt and the difference between income and spending in suicide trends as they plan suicide prevention measures. Further analyses of suicide data should be performed in a wide range of fields including legal medicine, toward a greater understanding of suicide risk factors.

Dermal absorption of gallium antimonide in vitro and pro-inflammatory effects on human dermal fibroblasts.

Gallium antimonide (GaSb) is a group III-V compound semiconductor with a comparatively narrow band gap energy (0.73 eV at 300 K) that allows efficient operation in the near-infrared region. This property may be useful in developing new biomedical instruments such as epidermal optoelectronic devices. The present study investigated the absorption of GaSb in pig skin in vitro for 24 h using Franz cells. A donor solution was prepared by soaking GaSb thin films in synthetic sweat. The results showed that both gallium and antimony penetrated the skin, and permeation and resorption occurred for gallium. Histopathological findings showed no inflammatory responses in pig skin exposed to GaSb for 24 h. Cytotoxicity was significantly elevated after 3 and 7 days, and pro-inflammatory cytokines and IL-8 levels were low after 1 and 3 days but elevated 7 days following the direct culturing of human dermal fibroblasts (HDF) on GaSb thin films. These results demonstrate that the short-term cytotoxicity and pro-inflammatory effect of GaSb on HDF were relatively low.

Evaluation of the functional effects of genetic variants‒missense and nonsense SNPs, indels and copy number variations‒in the gene encoding human deoxyribonuclease I potentially implicated in autoimmunity.

Genetic variants, such as single nucleotide polymorphisms (SNPs), in the deoxyribonuclease I (DNase I) gene which remarkably reduce or abolish the activity are assumed to be substantially responsible for the genetic backgrounds determining susceptibility to autoimmune dysfunction. Here, we evaluated many genetic variants, including missense and nonsense SNPs, and indel (inframe) variants in the gene, potentially implicated in autoimmune diseases as functional variants resulting in altered activity levels. Eighteen missense and 7 nonsense SNPs, and 9 indel (inframe) variants were found to result in loss of function and disappearance of DNase I activity. Furthermore, considering the positions in the DNase I protein corresponding to the various nonsense SNPs, all of the other nonsense SNPs and frameshift variants registered in the Ensembl database ( https://asia.ensembl.org ) appear likely to exert a pathogenetic effect through loss of the activity. Accordingly, a total of 60 genetic variants in the DNase 1 gene (DNASE1) inducing abolishment or marked reduction of the DNase I activity could be identified as genetic risk factors for autoimmunity, irrespective of how sparsely they were distributed in the population. It was noteworthy that SNP p.Gln244Arg, reportedly associated with autoimmunity and reducing the activity to about half of that of the wild type, and SNP p.Arg107Gly, abolishing the activity completely, were distributed worldwide and in African populations at the polymorphic level, respectively. On the other hand, with regard to copy number variations in DNASE1 where loss of copy leads to a reduction of the in vivo enzyme activity, only 2 diploid copy numbers were distributed in Japanese and German populations, demonstrating no loss of copy. These exhaustive data for genetic variants in DNASE1 resulting in loss or marked reduction of the DNase I activity are highly informative when considering genetic predisposition leading to autoimmune dysfunction.

Circulating cell-free DNA fragment analysis by microchip electrophoresis and its relationship with DNase I in cardiac diseases.

Circulating cell-free DNA (cfDNA) has been directly related to cancer, diabetes, stroke, systemic lupus erythematosus, trauma, rheumatoid arthritis, inflammation, infection, and myocardial infarction (MI). In this study, plasma cfDNA was extracted from the plasma of cardiac disease patients and the cfDNA fragment distribution as well as the relationships between cfDNA concentration and deoxyribonuclease I (DNase I) activity enzyme implicated in double-stranded DNA processing were examined. Results revealed that the cfDNA concentrations in patients with MI and cardiac angina were significantly higher than that in healthy control subjects. Microchip electrophoresis of plasma cfDNA revealed a single fragment (150-200 bp) in some healthy control subjects and three fragments (150-200 bp, 300-400 bp, and 500-600 bp) in all cardiac patient samples. Moreover, a cfDNA ratio of 150-200 bp/500-600 bp was significantly more prevalent in MI patients than in patients with other cardiac diseases (chest pain, cardiac angina, atrial fibrillation and cardiac failure). In addition, a positive correlation between DNase I activity and cfDNA concentration was observed. These results suggest that the plasma cfDNA in cardiac disease patients may originate from apoptosis and that the 150-200 bp/500-600 bp ratio for cfDNA may be a novel diagnostic indicator for MI.

Low genetic heterogeneity of copy number variations (CNVs) in the genes encoding the human deoxyribonucleases 1-like 3 and II potentially relevant to autoimmunity.

Deoxyribonucleases (DNases) might play a role in prevention of autoimmune conditions such as systemic lupus erythematosus through clearance of cell debris resulting from apoptosis and/or necrosis. Previous studies have suggested that variations in the in vivo activities of DNases I-like 3(1L3) and II have an impact on autoimmune-related conditions. The genes for these DNases are known to show copy number variations (CNVs) whereby copy loss leads to a reduction of the in vivo activities of the enzymes, thereby possibly affecting the pathophysiological background of autoimmune diseases. Using a simple newly developed quantitative real-time PCR method, we investigated the distributions of the CNVs for DNASE1L3 and DNASE2 in Japanese and German populations. It was found that only 2 diploid copy numbers for all of these DNASE CNVs was distributed in both of the study populations; no copy loss or gain was evident for any of the autoimmune-related DNase genes. Therefore, it was demonstrated that these human autoimmune-related DNase genes show low genetic diversity of CNVs resulting in alterations of the in vivo levels of DNase activity.

Analysis of copy number variation in the NEDD4L gene potentially implicated in body height in the Japanese population.

Recently it has been recognized that a considerable number of copy number variations (CNVs) are associated with diseases and other complex human traits. In our previous study, we developed a simple quantitative real-time PCR (Q-PCR) method for analysis of CNV copy number, which had the advantage of obviating the need for reference DNA with a known copy number. Using DNA samples obtained from 231 Japanese individuals, we applied this method for analyzing the copy number of a candidate CNV associated with body height, located in the neural precursor cell expressed, developmentally down-regulated 4-like, E3 ubiquitin protein ligase (NEDD4L) gene. In addition, the appropriateness of the results was evaluated and confirmed by quantification of amplicons with an Agilent 2100 Bioanalyzer. The NEDD4L gene encodes a member of the Nedd4 family of HECT domain E3 ubiquitin ligases. The target CNV located in the intron has been found to be significantly associated with height variation in Chinese. However, it remains unknown whether such an association exists in other populations, including Japanese. Analysis of the correlations between copy number and body height using ANOVA revealed no statistically significant correlations in Japanese.

Association of SNPs in transferrin and transferrin receptor genes with blood iron levels in human.

Iron is bound to mobile transferrin (TF) and ferritin in blood. TF receptors (TFRC and TFR2) regulate intracellular iron by delivering iron from TF into the cytoplasm. In this study, we examined the effects of 10 single nucleotide polymorphisms (SNPs) in each of the genes for TF and TF receptors on blood iron concentrations in Japanese subjects. Blood iron levels were determined by microwave plasma-atomic emission spectrometry and the SNPs were analyzed by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Blood iron levels in males were significantly higher than those in females. Therefore, the analysis was performed only in males. Blood iron concentrations did not correlate with age and postmortem intervals in males. Among the 10 SNPs in TF, TFRC, and TFR2 genes, significant associations were observed between TF genotypes (rs12769) and male iron concentrations. Individuals with genotype GG in rs12769 had significantly higher blood iron concentrations than those with GA. Previous studies have shown the association between high tissue iron concentrations and disease, liver iron levels are higher in infants dying from sudden infant death syndrome and decreased blood iron concentrations were observed in critically ill children. Therefore, rs12769 in TF might be related to diseases and mortality risk.

Discrimination Between Infant and Adult Bloodstains Using Micro-Raman Spectroscopy: A Preliminary Study.

In the present study, we used micro-Raman spectroscopy with high-resolution analysis to discriminate between bloodstains from infants and bloodstains from adults. Raman peaks were detected at 674, 754, 976, 1002, 1105, 1127, 1176, 1248, 1340, 1368, 1390, 1560, and 1611 cm-1 ; these peaks were derived from hemoglobin, albumin, and glucose. However, a peak was obtained at 1105 cm-1 , which was assigned to histidine; this peak was observed only for bloodstains from adults. Human adult hemoglobin (HbA) is composed of an α2 ß2 tetramer structure, whereas human fetal hemoglobin (HbF) is composed of an α2 γ2 . Therefore, the lack of a Raman peak at 1105 cm-1 in bloodstains from infants indicates the possibility of two histidine substitutions (His116Ile and His143Ser) in the γ chain of HbF. This study discriminates between bloodstains from infants and bloodstains from adults using micro-Raman spectroscopy, with beneficial implications in forensic science.

Association of SNPs in genes encoding zinc transporters on blood zinc levels in humans.

Zinc homeostasis in cells depends on zinc transporters, which are divided into 2 families: ZnT (SLC30A) and ZIP (SLC39A). In this study, we examined the effect of 20 single nucleotide polymorphisms (SNPs) in 10 genes encoding zinc transporters on blood zinc concentration in Japanese subjects (n = 102). Blood zinc levels were determined by microwave plasma-atomic emission spectrometry, and SNPs were analyzed by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Among the 20 SNPs examined, 3 SNPs (SLC30A3 rs11126936, SLC39A8 rs233804, and SLC39A14 rs4872479) were significantly associated with blood zinc concentration. Individuals with genotype TT and TG in rs11126936 showed significantly higher blood zinc concentrations than those with GG. As for rs233804, individuals harboring the A allele had significantly higher blood zinc concentrations than those without this allele. Furthermore, the genotype TT and TG in rs4872479 had significantly higher blood zinc concentrations than those with GG. Among these three SNPs, combination of SLC30A3 rs11126936 and SLC39A8 rs233804 may strongly affect blood zinc levels. This study is the first comprehensive investigation of the effect of SNPs in genes encoding zinc transporters on blood zinc concentration. Adverse effects of zinc deficiency are reported and above 3 SNPs may be related to genetic susceptibility to zinc deficiency.

Simple screening method for copy number variations associated with physical features.

Recent studies of copy number variations (CNVs) associated with physical features, such as body mass index, body height or bone length, have suggested that such CNVs could serve as markers in forensic cases involving unidentified individuals. However, the process of cataloging CNVs has been slow because of the cumbersome nature and low reliability of the procedures involved. Here we describe a simple quantitative real-time PCR (Q-PCR) method for screening of medicolegally useful CNVs, which does not require reference DNA with known copy number. The first step is to prepare a chimeric plasmid vector including one copy each of the single-copy gene-specific sequence as the internal standard, and the target CNV-specific sequence. To assess the validity of this new method, we analyzed CNVs in the LTBP1 and ETV6 gene regions, both of which are candidate CNVs associated with body height. The PCR efficiencies for the single-copy (reference) gene and the target CNV were similar, indicating that quantitation was reliable. Furthermore, simulated analysis of the LTBP1 CNV using mock samples prepared by mixing vectors in varying proportions showed that this analytical method allowed correct determination of the LTBP1 copy number. These results demonstrated that our simple method has considerable potential for screening of trait-related CNVs that would be useful for forensic casework.

Survey of single-nucleotide polymorphisms in the gene encoding human deoxyribonuclease I-like 2 producing loss of function potentially implicated in the pathogenesis of parakeratosis.

Dysfunction of DNase I-like 2 (DNase 1L2) has been assumed to play a role in the etiology of parakeratosis through incomplete degradation of DNA in the epidermis. However, the pathogenetic background factor for such pathophysiologic conditions remains unknown. In this context, non-synonymous single-nucleotide polymorphisms (SNPs) in DNASE1L2 that would potentially result in loss of in vivo DNase 1L2 activity might serve as a genetic risk factor for such pathophysiologic conditions. Our aim was to effectively survey the non-synonymous SNPs of DNASE1L2 that would produce a loss-of-function variant of the enzyme together with a genetic distribution in the various populations. Here, the effects of all of the SNPs predicted by PolyPhen-2 analysis to be "probably damaging" (score = 1.000), and derived from frameshift/nonsense mutations, on the activity of DNase 1L2 were examined using the corresponding DNase 1L2 variants expressed in COS-7 cells. Genotyping of these SNPs was also performed in three ethnic groups including 14 different populations. Among the 28 SNPs examined, the minor allele of 23 SNPs was defined as a loss-of-function variant resulting in loss of DNase 1L2 function, indicating that Polyphen-2 analysis could be effective for surveys of at least non-synonymous SNPs resulting in loss of function. On the other hand, these minor alleles were not distributed worldwide, thereby avoiding any marked reduction of the enzyme activity in human populations. Furthermore, all of the 19 SNPs originating from frameshift/ nonsense mutations found in DNASE1L2 resulted in loss of function of the enzyme. Thus, the present findings suggest that each of the minor alleles for these SNPs may serve as one of genetic risk factors for parakeratotic skin diseases such as psoriasis, even though they lack a worldwide genetic distribution.

An autopsy case of spontaneous esophageal perforation (Boerhaave syndrome).

A 45-year-old male, an alcohol addict with asthma, was found dead in his home, after several days of continued drinking. A forensic autopsy was performed 3days after the discovery of his death in order to specify the cause of death. A longitudinal perforation penetrating all layers of the esophagus measuring 1.8cm was present on the left wall approximately 2.0cm from the gastroesophageal junction. There were 1900mL of greenish to brownish turbid liquid in the left pleural cavity and 150mL of greenish viscous liquid in the stomach. Histopathologically, an infiltration of numerous neutrophils was evident in the submucosa layer, proper muscular layer, and serous membrane of the esophagus, corresponding to the esophageal laceration. The serum C-reactive protein (CRP) concentration was determined to be 3.1mg/dL. The alcohol concentrations were determined to be 1.49mg/g in the right cardiac blood, 1.31mg/g in the left cardiac blood, and 2.48mg/g in urine. Based upon the autopsy and histopathological findings, as well as the biochemical and toxicological analyses, we concluded that the cause of death was respiratory failure by pleural effusion, resulting from spontaneous esophageal perforation. This was the first report of a spontaneous esophageal perforation eventually causing respiratory failure.