Ryouichi Tsuda

Nagasaki University, Nagasaki-shi, Nagasaki-ken, Japan

Are you Ryouichi Tsuda?

Claim your profile

Publications (29)40.85 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigated the transcriptome profile of mechanical asphyxia and decapitation at 60 min after death using serial analysis of gene expression. After comparing the results, 11 genes were significantly increased by the mechanical asphyxia treatment in the mouse lung. Of those genes, quantitative real-time PCR revealed that dual specificity phosphatase 1 (Dusp1), TGF-beta stimulated gene 22, domain family protein 3 (TSC22d3) and Luc7 homolog (Saccharomyces cerevisiae)-like (Luc7l) after asphyxia were more significantly increased than those after decapitation. Dusp1 inactivated mitogen activated protein kinase, which functions in cell proliferation. However, the consumption of oxygen had a disadvantageous effect on survival, because tissue or cells were not able to produce energy by internal respiration under the suddenly hypoxic condition following asphyxia. The increased transcripts of Dusp1 following asphyxia suppressed oxygen consumption. TSC22d3 was isolated as a TGF-beta-inducible gene and it is also identified as a glucocorticoid (GC)-induced leucine zipper (GILZ). GC was released from the adrenal gland via HPA axis under the hypoxic condition. Especially in acute suffocation, GC rapidly increased. Therefore, the increase in TSC22d3 may be induced by the increased GC following asphyxia. We were unable to clarify the Luc7l increase, because there are no reports in relation to asphyxia. In addition, GILZ mediates the antiproliferative activity of glucocorticoids. We thought that the increasing TSC22d3 may lead to the suppression of oxygen consumption to avoid wasting energy, as in proliferation, the same as the increase in Dusp1. Our data indicated that the determination of the protein product level in the lung could help in diagnosing asphyxia. In addition, these data may contribute to revealing the patho-physiology of asphyxia and to help diagnose asphyxia, including hanging.
    Legal Medicine 05/2009; 11(4):181-5. · 1.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: RNA analysis has been applied to forensic work to determine wound age. We investigated mRNA expression using quantitative RT-PCR of ten genes, including c-fos, fosB, mitogen-activated protein kinase phosphatase-1 (MKP-1), CD14, chemokine (C-C motif) ligand 9 (CCL9), placenta growth factor (PlGF), mast cell protease-5 (MCP-5), growth arrest specific 5 (Gas5), beta-2 microglobulin (B2M) and major urinary protein-1 (MUP-1), in terms of repair response in adult mice. The expression level of c-fos, fosB and MKP-1 transcripts increased drastically, peaked within 1h, and that of the CD14 and CCL9 transcripts peaked from 12 to 24h. An increase in PlGF and MCP-5 mRNA appeared on about day 5. Gas5, B2M and MUP-1 transcripts showed no significant change. Each gene had differentially expressional patterns with time-course. Our result implied that the observation of the 7 genes in wounded skin could serve to aid in the accurate diagnosis of wound age.
    Legal Medicine 11/2008; 11(2):70-5. · 1.44 Impact Factor
  • Kazuya Ikematsu, Ryouichi Tsuda, Ichiro Nakasono
    [Show abstract] [Hide abstract]
    ABSTRACT: Cocaine abuse represents a worldwide significant issue because it is one of the most dangerous commonly used illicit drugs. Both psychiatric and neurological symptoms are usual manifestations of cocaine toxicity. A few reports mention that certain transcripts of the central nervous system are changed by cocaine administration. Differential display (DD) detects mRNA variations among many different kinds of tissues and cells and is more highly sensitive. We analysed the transcriptome in the brain of murine models following cocaine administration using a fluorescence differential display (FDD). Seventeen differentially expressed genes were found with FDD, and confirmed by nucleotide sequence and real time PCR. Of these genes, four genes including silencer of death domain (SODD) and Mpv 17-like protein (M-LP) increased. Of the remaining 13 genes containing A20 binding inhibitor of NF-κB activation-2 (ABIN-2) decreased. Increased SODD may inhibit signal-transduction following TNF stimulation for apoptosis. Raised M-LP might suppress apoptosis to reduce ROS via SOD production. The decrease of ABIN-2, which meant the increase of NF-κB activation via the reducing of the A-20 and ABIN02 complex, might enable apoptosis suppression. Therefore, the expressions of all genes identified in this study might lead to the prevention of neuronal apoptosis. In this study, we found the specific alteration of transcripts following the administration of cocaine. The results of this study may contribute to revealing the pathophysiology of cocaine in the brain.
    Forensic Science International Genetics Supplement Series 08/2008; 1(1):563-564.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In forensic pathology, the reactions that occur in the body from somatic death to cell death are commonly termed "supravital reactions". There are many reports of grossly visible and microscopic supravital reactions; however, few papers are available on the supravital reaction concerning gene expression. The aim of this study was to examine the gene expression of immediate early genes (IEGs) including c-fos, fos-B and c-jun in mechanically asphyxiated mouse brain and lung after somatic death and to identify the IEGs expressed at the point of supravital reaction in the brain and lung. Our results confirm that the expression of IEGs changed after death during supravital reaction and that the alterations differed according to the cause of death and the types of organ examined. In addition, IEG expression significantly increased following mechanical asphyxia. These results suggest that there is a specific pattern of gene expression following asphyxia. It is therefore important to identify the specific genes involved, as this may give significant information to aid in the post-mortem diagnosis of strangulation and hanging.
    Forensic science international 08/2008; 179(2-3):152-6. · 2.10 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Toluene, an abused substance in Japan, is well known as a neurotoxic chemical and has been shown to have neurobehavioral and electrophysiological effects. We used a fluorescence differential display PCR technique to analyze the genes expressed in the brain by toluene inhalation. We found 20 genes that were differentially expressed by toluene exposure. We confirmed by re-amplified PCR, nucleotide sequence and quantitative real-time PCR that of the 20 cDNAs, only 10 showed reproducible expression patterns by toluene inhalation. Of these genes, four had high homology with known genes (MIDA1, PEBP2 beta, phosphatidylserine synthase 2 and SKAP55) and six fragments were new sequence tags of unknown genes. This result may contribute to reveal the patho-physiological effects of toluene inhalation on rat brain.
    Legal Medicine 10/2007; 9(5):265-9. · 1.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Fluorescence differential display (FDD) and comparative RT-PCR have been used extensively to detect differentially expressed genes. We investigated hypoxia-induced gene expression in the brain by FDD-PCR and comparative RT-PCR. Mice were anaesthetized after which hypoxia was induced by neck ligation for 1 min or 25 min, then were killed by decapitation, and the brains were dissected either immediately or 30 min after death (Group A1-0, Group A25-0, Group A1-30 and Group A25-30). Control mice without ligation of the neck were killed by decapitation under anaesthesia immediately (Group C-0) or 30 min after death (Group C-30). FDD-PCR, sequence analysis and comparative RT-PCR revealed that mitochondrial thymidine kinase 2, Rab6, selenoprotein T and two novel cDNAs were enhanced in Group A25-0 and Group A25-30 compared with the other groups. In Group A25-30, only RAP2 interacting protein and another novel cDNA were induced. In Group A25-0, one novel gene was detected. These findings were consistent with the results of statistical analysis by ANOVA. No differences of band pattern were observed among Groups A1-0, A1-30, C-0 and C-30. The genes exhibiting altered expression were associated with vital cellular functions, e.g., intracellular signaling and mitochondrial metabolism. In addition, we identified four novel genes, expressed after extended hypoxic conditions in mouse brain with suffocation. These results may contribute to clarify the pathophysiology of asphyxia in the brain and aid in the diagnosis of suffocation.
    Forensic science international 08/2007; 169(2-3):168-72. · 2.10 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: alpha2-seminoglycoprotein (alpha2-SGP), purified from human seminal plasma, is a carrier of glycoprotein for the ABO blood grouping. The alpha2-SGP exists in the secretions of the seminal vesicle and various glands. However, the function of alpha2-SGP is, as yet, unknown. In this study, we determined that two internal amino acid sequences of 8 and 12 residues of alpha2-SGP were Ala-Val-Asp-Thr-Trp-Ser-Trp-Gly and Thr-Leu-Gln-Ala-Leu-Glu-Phe-His-Thr-Val-Pro-Phe. These sequences were completely coincident with the domain 3 of human Mac-2 binding protein (M2BP), which was identified as a tumor-associated antigen. In addition, we also confirmed an alpha2-SGP binding activity to galectin-3 that was one of a ligand for M2BP, and the immunological cross-reactivity between alpha2-SGP and M2BP. These findings strongly suggested that alpha2-SGP was identical with M2BP.
    Legal Medicine 11/2006; 8(5):273-8. · 1.44 Impact Factor
  • Kazuya Ikematsu, Ryouichi Tsuda, Ichiro Nakasono
    [Show abstract] [Hide abstract]
    ABSTRACT: We analyzed the gene expression pattern in mouse skin following compression of the neck by fluorescent mRNA differential display (FDD-PCR). RNA was isolated from the skin tissue immediately or 30 min after ligation at the neck for 25 min resulting in death (Group A-0, Group A-30). Control mice underwent no compression of the neck and were killed by decapitation (Group C-0, Group C-30). FDD-PCR and sequence analysis revealed that the faciogenital dysplasia gene (Rho member families) and secreted frizzled related protein 1 (modulator of Wnt networks) were enhanced only in the Group A-30. In addition, common salivary protein 1 and mouse 0 day neonate skin cDNA clone z4631433E12 from the RIKEN full-length enriched library were also induced in Groups A-0 and A-30. These findings were consistent with the results of statistical analysis by ANOVA following quantitative real-time PCR. No differences in band pattern were observed between Group C-0 and Group C-30. Therefore, our findings suggested that the altered expression of genes was associated with signal transduction. The results may contribute to clarifying the pathophysiology of compression of the skin and may be useful in the diagnosis of suffocation.
    Legal Medicine 04/2006; 8(2):128-31. · 1.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The expression of oxygen regulated protein 150-kDa (ORP-150) was strongly induced in human brain under the hypoxic conditions. We examined the expression of ORP-150 in the brain samples, and discussed its significance in forensic practice. The cerebral cortexes of 31 cases (asphyxia: 9 cases, hypothermia: 4, exsanguinations: 5, CO intoxication (CO): 6, sudden cardiac death (SCD): 7) were used for this study. Each tissue section was incubated with anti-ORP-150 polyclonal antibody and the number of ORP-150 positive cells were counted. In the multiple linear regression method, the estimated regression coefficient of ORP-150 on age was significant (P=0.039) thus, we could find that the ORP-150 expression level depended on age. Using analysis of covariance, we compared the means of ORP-150, LSMEAN, which means hypothetic average value excluding influence of age, for each cause of death. The LSMEAN+/-SE was 84.74+/-9.03 in hypothermia, 57.52+/-6.34 in asphyxia, 46.68+/-6.70 in CO, 24.84+/-8.05 in exsanguinations, and 16.24+/-7.35 in SCD. As a result of the analysis, the LSMEAN of the ORP-150 expression level was related to the cause of death. There might be differences in the duration of brain ischemia before death. For example, SCD is presumed to be instant death, while brain ischemia continues for several minutes in asphyxia, CO and exsanguinations, and for several hours in hypothermia cases. Therefore, the immunohistochemical and morphometrical analysis of ORP-150 in the brain may be very useful to determine the duration of brain ischemia before death in forensic autopsy cases.
    Legal Medicine 05/2004; 6(2):97-101. · 1.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The oxygen regulated protein 150-kDa (ORP-150) is only induced in hypoxic conditions. We performed an immunohistochemical and morphometrical study on the expression of ORP-150 in the brains of sudden infant death (SID) victims. The cerebral cortexes of 18 infants were used for this study. Each tissue section was incubated with anti-ORP-150 polyclonal antibodies and the number of ORP-150 positive cells was counted. In the cluster analysis, the 18 cases were classified into three groups (A-C groups). Group A was composed of six sudden infant death syndrome (SIDS) cases and its mean value of ORP-150 positive cells was 66.75+/-3.44, Group B (six severe respiratory infectious disease such as pneumonia and bronchitis including sepsis): 39.50+/-2.52 and Group C (five SIDS and one severe respiratory infectious disease): 16.00+/-2.92, respectively. These results might reflect chronic hypoxic condition before death, because ORP-150 is only induced when a hypoxic condition exist, but not acute hypoxia. And chronic hypoxic state is likely to be antecedent to SIDS. Therefore, immunohistochemical analysis of OPR-150 in the brain of SID cases may be very useful to differentiate between SIDS and acute asphyxia.
    Legal Medicine 04/2003; 5(1):15-9. · 1.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigated the dynamics of the induction of heme oxygenase-1 (HO-1) in the human brain after death caused by traumatic brain injury (TBI). HO-1 was found to stain neurons and microglia/macrophages in cases with TBI, whereas no positive staining except for a few round cells in the arachnoidal space was observed in control cases. In a case with 7h survival, a considerable number of HO-1 positive neurons and microglia were observed. The number of HO-1 positive cells and level of HO-1 staining gradually increased up to 24h survival. Although HO-1 positive neurons were seldom observed in cases with more than 7-day survival, HO-1 positive microglia were still observed even in cases with 5-month survival. The results indicate that HO-1 may be induced by TBI in human cases, and suggest that prolonged HO-1 induction in microglia might reflect its role in protecting those cells from secondary damage including oxidative stress.
    Legal Medicine 04/2003; 5 Suppl 1:S278-9. · 1.44 Impact Factor
  • Wataru Hirose, Kazuya Ikematsu, Ryouichi Tsuda
    [Show abstract] [Hide abstract]
    ABSTRACT: Heme oxygenase-1 (HO-1) is a 32 kDa heat shock protein (HSP) that catalyzes heme to biliverdin, free iron and carbon monoxide in the brain. Furthermore, the release of free ferrous ion by HO-1 plays an essential role in ferritin synthesis, and ferritin stores iron either for intracellular utilization, or for detoxification. It is well known that HO-1 immunoreactivity is enhanced greatly in neurons and glia of the hippocampus and cerebral cortex in various pathophysiological conditions. The expression of HSP 70 is well known for the age-associated increase, but the expression modalities of HO-1 and ferritin associated with aging are still unknown. A study was therefore performed to examine the correlations in the expression of HO-1 and ferritin with age using immunohistochemistry. We investigated 31 autopsied brains (3-84-year-olds) without traumatic brain injury and neurodegenerative disease. The specimens were taken from the cerebral cortex and hippocampus. In the cerebral cortex, age (aging) had a statistically significant positive correlation with HO-1 (r=0.894, P<0.01) and ferritin (r=0.731, P<0.01). In the hippocampus, age had a significant positive correlation with only HO-1 (r=0.660, P<0.01). These results showed that HO-1 and ferritin underwent an age-related increase in human brain, especially in the cerebral cortex. Our results also indicate that various stress responses may persist in the aged human brain.
    Legal Medicine 03/2003; 5 Suppl 1:S360-6. · 1.44 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: It is well recognized that glutamate is the major excitatory neurotransmitter, which is removed from the synaptic cleft by excitatory amino acid transporter 2 (EAAT2) located on the perisynaptic astrocytes and that neuronal death has been associated with an increased extracellular glutamate concentration. In this study, we have immunohistochemically demonstrated the expression of EAAT2 protein in the human brain after traumatic brain injury (TBI). The EAAT2 expression patterns can be divided into three types: continuous and highly extensive staining (E); continuous but sporadic staining (M); and sporadic pattern staining (S). In six of the nine short survival cases studied (1 h to 1 day), continuous and highly extensive staining for EAAT2 (E type) was observed in the ipsilateral cerebral cortex. On the other hand, we were able to demonstrate weak staining (S and M types) in 5 of the 7 long survival cases (> or =1 day) and in 12 of the 14 very short survival cases (<1 h) studied. Similar findings were obtained in the contralateral cerebral cortex and also in the ipsilateral hippocampus. In addition, positive staining for glial fibrillary acidic protein was detected around the cerebral contusion, but the EAAT2-positive expression was not observed in the same region for all of the six short and long survival cases (> or =1 h) after TBI. These findings clearly showed the differences in EAAT2 expression in the cerebral cortex according to the survival time and severity of cerebral contusion after TBI. Therefore, we emphasized that EAAT2 might play an important role in contributing to extracellular glutamate concentrations and secondary brain injury after TBI.
    Forensic Science International 12/2002; 130(2-3):83-9. · 2.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigated the dynamic induction/expression of inducible nitric oxide synthase (iNOS) using human brains made available through death by traumatic brain injury (TBI). Astrocytes, microglia, and neutrophils were identified in tissue using immunohistochemical staining with antibodies against glial fibrillary acidic protein (GFAP), MHC class II antigen, and neutrophil elastase, respectively. The localization of iNOS protein in each of these cell types was evaluated using immunohistochemistry. Within 2 days of injury, iNOS immunoreactivity was not detected. However, after 2 days, immunoreactivity was detected in the traumatized brain. The iNOS immunoreactivity was localized on neutrophils and microglia/macrophages in the areas around the tissue necrosis in the traumatized cortical hemisphere, in the deep part of the cortex and the dentate gyri of the hippocampi adjacent to the hemorrhage, and within the cytoplasm of vascular smooth muscle cell of a small artery or arteriole surrounding the injured region. This reactivity was absent after 8 days post-injury.These observations confirmed the prolonged induction of iNOS within various cells in the injured brain. These responses suggest that iNOS plays a crucial role in cerebrovascular damage and/or secondary brain damage subsequent to traumatic brain injury. Furthermore, the dense nitric oxide (NO) generated by iNOS may play a role in neuronal cell death after injury.
    Forensic Science International 01/2002; 123(2-3):142-9. · 2.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Glutamate is the major excitatory neurotransmitter and the greater part of this amino acid is removed from the synaptic cleft by excitatory amino acid transporter 2 (EAAT2) located on perisynaptic astrocytes. Recently, it was reported that the EAAT2 protein content changed in rats following forebrain ischemia and administration of methamphetamine. We planned to demonstrate the immunohistochemical distribution of EAAT2 in the human brain and discuss the significance of its pathophysiological roles. Thirty-two cases were used from forensic autopsies. The tissues were sampled from the cerebral cortex, striatum and hippocampus. The distribution of EAAT2 was difficult to identify in cases of electrical fatalities. However, continuous and extensive staining of EAAT2 was observed in cases of death from hypothermia. In almost all asphyxia death, we were able to observe a weak stain of EAAT2. In case of solvent abuse, EAAT2 staining was continuous and extensive as in the cases of hypothermia, and patchy negative zones were mixed. This study clearly showed the differences in EAAT2 localization according to the cause of death. These findings suggested that the differences in EAAT2 staining depended on the cause and course (pathophysiological conditions) of death.
    Forensic Science International 05/2001; 118(1):49-55. · 2.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal disorder. In forensic cases, post-mortem diagnosis of NMS is sometimes difficult if ante-mortem information, such as neuroleptic ingestion or signs and symptoms, cannot be obtained. A 39-year-old Japanese male on a neuroleptic treatment regimen suddenly became agitated and died. Autopsy revealed muscle rigidity and hyperthermia. Post-mortem examination of blood revealed elevation of creatine phosphokinase-MM (CK-MM) and lactate dehydrogenase-4 and dehydrogenase-5 (LDH-4 and LDH-5). In renal glomeruli and tubules, myoglobin was stained immunohistochemically. From these findings, the cause of death was considered to be NMS. To support the diagnosis of NMS, both skeletal and cardiac muscles were stained with actin, myoglobin, desmin and mitochondria antibodies immunohistochemically. Actin, myoglobin, desmin, and mitochondria had been lost from skeletal, but not from the cardiac muscle, which suggested that only the skeletal muscle was damaged. Moreover, because mitochondria had disappeared only from the skeletal muscle, it was considered that skeletal muscle degeneration was caused by mitochondrial damage. Therefore, it is suggested that immunostaining of skeletal muscle by antibodies for muscle-associated proteins and mitochondria is useful to corroborate a diagnosis of NMS.
    Forensic Science International 02/2001; 115(1-2):155-8. · 2.12 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The brain stem hypoglossal nucleus (HN) is the center of nerves innervating the upper respiratory tract and is related to control of mastication, deglutition, speech and respiration. To elucidate the relationship between asphyxia and the HN, we investigated the change of hypoglossal neurons in cases of hanging, strangulation, smothering, choking, drowning and respiratory failure. Using immunohistochemical techniques, we observed the brain stem HN with antibodies against microtubule-associated protein 2 (MAP2), muscarinic acetylcholine receptor (mAChR), c-fos gene product (c-Fos) and 72 kD heat-shock protein (HSP70). MAP2, a cytoskeletal protein of the neuron, is a marker of neuronal damage. Muscarinic AChR was used as a marker of neuronal membrane and ACh signaling. We employed both HSP70 and c-Fos as markers of stress- or damage-related events. We measured the percentage of immunopositive neurons in total neurons of HN. Drowning produced higher expression of HSP70 and c-Fos than other causes of asphyxia, suggesting that drowning induces more severe damage in HN neurons. Furthermore, it was suspected that neuronal changes in drowning might relate to functions of the HN. These observations indicate that immunohistochemical examination of the brain stem HN could provide useful information for determining the cause of asphyxia.
    The Journal of Medical Investigation 03/2000; 47(1-2):76-9.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A polymorphic CA repeats (YCA II) was previously reported on the human Y chromosome. We have used a simple technique based on polymerase chain reaction amplification followed by native polyacrylamide gel electrophoresis to study the inheritance, the genetic stability, and the allele frequency distribution of this polymorphism in the Japanese. We found seven haplotypes which were tentatively designated as: A[(CA)19/(CA)21], B[(CA)19/(CA)22], C[(CA)19/(CA)23], D[(CA)19/(CA)19], E[(CA)21/(CA)21], F[(CA)22/(CA)22], and G[(CA)23/(CA)23]. The frequencies of these haplotypes were: A, 0.21; B, 0.29; C, 0.37; D, 0.02; E, 0.02; F, 0.07; G, 0.01. There was complete concordance with each father-son pairs. The results indicate the dinucleotide system YCA II is very useful for investigation of forensic samples, especially mixed stains in sexual offence cases.
    Journal of Forensic Sciences 06/1999; 44(3):588-91. · 1.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Several nuclei in brain stem are well known to play an important role in supporting human life. However, the connection between neural changes of brain stem and the cause of death is not yet fully understood. Previously, in sudden infant death syndrome (SIDS) it has been suggested that impaired cardioventilatory control might contribute to cause of death. So, to investigate the brain stem damage in SIDS, neural changes of the arcuate nucleus (ARC), the hypoglossal nucleus (HN) and the inferior olivary nucleus (IO) was examined using immunohistochemical technique. Brain was fixed with phosphate-buffer formalin, and the brain stem was horizontally dissected at the level of apex, then embedded in paraffin. The sections were stained with the antibodies against microtubule-associated protein 2 (MAP2), muscalinic acetylcholine receptor (mAChR), c-fos gene product (c-Fos) and 72 kD heat-shock protein (HSP70). Morphological changes of neurons in three nuclei were not evident. Moreover, because MAP2 degeneration and expression of HSP70 and c-Fos were not observed, neuronal damage in those nuclei was not suspected. However, although there was no abnormality of mAChR immunostaining in HN and IO, the rate of mAChR-immunopositive neurons in ARC was less than that in control. These observations indicate that immunohistochemical study on the neuronal changes in ARC can provide useful information for diagnosing SIDS.
    Nihon hōigaku zasshi = The Japanese journal of legal medicine 01/1999; 52(6):350-4.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Several nuclei in brain stem are well known to play an important role in supporting human life. However, the connection between neural changes of brain stem and the cause of death is not yet fully understood. To investigate the correlation of brain stem damage with various cause of respiratory disorders, neural changes of the arcuate nucleus (ARC), the hypoglossal nucleus (HN) and the inferior olivary nucleus (IO) were examined using immunohistochemical technique. Based on the cause of death, the forensic autopsy cases were divided into 5 groups as follows. Group I: hanging, ligature strangulation and manual strangulation, Group II: smothering and choking, Group III: drowning, Group IV: respiratory failure, control group: heat stroke and sun stroke. Brain was fixed with phosphate-buffer formalin, and the brain stem was horizontally dissected at the level of apex, then embedded in paraffin. The sections were stained with the antibodies against microtubule-associated protein 2 (MAP2), muscalinic acetylcholine receptor (mAChR), c-fos gene product (c-Fos) and 72 kD heat-shock protein (HSP70). Three nuclei showed no obvious morphological changes in all examined groups. However, in case of asphyxia (Group I to III), neurons in HN were positively stained with both HSP70 and c-Fos antibodies. This may indicate that the occlusion of upper airway results in the neuronal damage of HN without their morphological changes. Positive staining of HSP70 and c-Fos in IO was more frequently observed in Group III than other 4 groups. Since IO is involved in maintaining body balance which is often disturbed by drowning, it seems possible that neuronal damage in IO observed in drowning may be related to the disturbance of body balance. These observations indicate that immunohistochemical study on the damage to neurons in brain stem nuclei can provide useful information for determining the cause of death.
    Nihon hōigaku zasshi = The Japanese journal of legal medicine 01/1999; 52(6):345-9.

Publication Stats

226 Citations
40.85 Total Impact Points


  • 2002–2009
    • Nagasaki University
      • • School of Medicine
      • • Department of Forensic Pathology and Science
      Nagasaki-shi, Nagasaki-ken, Japan
  • 1994–2008
    • Nagasaki University Hospital
      Nagasaki, Nagasaki, Japan
  • 1999–2001
    • The University of Tokushima
      • School of Medicine
      Tokusima, Tokushima, Japan