Biomedical subjects

T Takatori

Publications and source records attributed to T Takatori.

At least 37 records · Page 2Linked to original sources

PubMed1999

A 'keyhole lesion' gunshot wound in an adipocere case.

A corpse completely converted into adipocere and showing two adjacent bone defects--a typical gunshot entrance wound and a keyhole lesion--is reported. Postmortem changes, a comminuted fracture of the cranial base, and destruction of the bullets made it impossible to determine the direction of fire through the keyhole lesion. Gunshot wounds may show various atypical forms, including keyhole lesions, and especially in old corpses, the distinction between an entrance wound and an exit wound can be very difficult, even if a careful complete autopsy is performed.

Journal Article↗

PubMed1998

Calcium is required for quasi-lipoxygenase activity of hemoproteins.

Bovine and guinea pig heart homogenates, porcine leukocyte homogenate, and human hemolysate were found to vigorously oxidize linoleic acid, with lipoxygenase-like activity, to its hydroperoxy, epoxy, hydroxy-epoxy, and keto compounds in the presence of calcium chloride. In the absence of calcium, the reaction was significantly reduced. Attempts to characterize this quasi-lipoxygenase activity revealed that calcium potentiated the quasi-lipoxygenase activities of hemoproteins (hemoglobin, myoglobin, myeloperoxidase, catalase, cytochrome c) and hemin at the physiological pH of 7.5. Lipid peroxidation by hemoproteins was inhibited by albumin and erythrocyte membranes in blood, as well as by a low concentration of calcium in cells. However, it seems possible that in extracellular fluid, which contains a high concentration of calcium and a low concentration of albumin, hemoprotein released from damaged cells could oxidize unsaturated fatty acids derived by phospholipase-A2 from phospholipids of damaged cellular membranes. In a model of quasi-lipoxygenase activation under such conditions, lipids of erythrocyte membranes were oxidized by hemoglobin in the presence of phospholipase-A2 and calcium. The effect of nitrogen oxide, paraquat, and bleomycin on oxidation by hemoproteins and hemin was also discussed.

Animals↗

PubMed1998

Evidence for an antemortem injury of a burned head dissected from a burned body.

A 41-year-old woman was killed following blows to the head with a bat. Her body was burned and her head was dissected with a saw and hidden in the soil. Although the body was discovered within a few days of her death, the putrescent head was not located until four months later. A fracture of the left temporal bone was found in the head, which was partially charred. The confession of the murder suspect was unreliable, and the police suggested that the cause of death may not have been a head injury but asphyxia, and that the bone fracture to the head may have been caused after its dissection. It was therefore necessary to determine when the fracture was formed. The fracture line continued to the base of the skull, indicating that it was not due to heat. Magnetic resonance computed tomography (MR-CT) indicated the existence of a blood clot in the left mastoid cells, across which the fracture line passed. Upon sectioning of the skull with a saw, a dark red clot was located in the left mastoid cells, indicating that bleeding had occurred before the body was set alight. It seemed most logical to assume that the bone fracture was formed when the victim was alive, or before her body was burned.

Adult↗

PubMed1998

Calcium ions potentiate lipoxygenase activity of cytochrome c at the physiological pH.

Cytochrome c oxidized linoleic acid, with lipoxygenase-like activity, to 9-hydroperoxy-10,12-octadecadienoic acid (9-HpODE), 13-hydroperoxy-9,11-octadecadienoic acid (13-HpODE), 13-keto-9,11-octadecadienoic acid (13-KODE), and hydroxy-epoxy-octadecenoic acids (HEPOs) in the presence of calcium chloride at the physiological pH of 7.5. In the absence of calcium, the reaction was remarkably reduced. Statistically significant increase of 13-KODE was observed 1 min after the reaction was started by adding calcium. Calcium chloride at concentrations as low as 30 microM caused statistically significant increase of 13-KODE production in the presence of 1 microM cytochrome c, and cytochrome c at concentrations as low as 10 nM caused statistically significant increase of 13-KODE production in the presence of 2 mM calcium. The addition of bleomycin enhanced the reaction, and the addition of adriamycin attenuated the reaction. The same oxidized linoleic acid products were found in the submitochondrial particles which were hydrolyzed by phospholipase-A2 in the presence of calcium. Lipoxygenase activity potentiated by calcium may be involved in the lipid peroxidation in the submitochondrial particles hydrolyzed by phospholipase-A2.

Animals↗

PubMed1998

Detection of the sarin hydrolysis product in formalin-fixed brain tissues of victims of the Tokyo subway terrorist attack.

One of the hydrolysis products of sarin (isopropyl methylphosphonofluoridate) was detected in formalin-fixed brain tissues of victims poisoned in the Tokyo subway terrorist attack. Part of this procedure, used for the detection of sarin hydrolysis products in erythrocytes of sarin victims, has been described previously. The test materials were four individual cerebellums, which had been stored in formalin fixative for about 2 years. Sarin-bound acetylcholinesterase (AChE) was solubilized from these cerebellums, purified by immunoaffinity chromatography, and digested with trypsin. Then the sarin hydrolysis products bound to AChE were released by alkaline phosphatase digestion, subjected to trimethylsilyl derivatization (TMS), and detected by gas chromatography-mass spectrometry. Peaks at m/z 225 and m/z 240, which are indicative of TMS-methylphosphonic acid, were observed within the retention time range of authentic methylphosphonic acid. However, no isopropyl methylphosphonic acid was detected in the formalin-fixed cerebellums of these 4 sarin victims, probably because the isopropoxy group of isopropyl methylphosphonic acid underwent chemical hydrolysis during storage. This procedure will be useful for the forensic diagnosis of poisoning by protein-bound, highly toxic agents, such as sarin, which are easily hydrolysed. This appears to be the first time that intoxication by a nerve agent has been demonstrated by analyzing formalin-fixed brains obtained at autopsy.

Acetylcholinesterase↗

PubMed1998

Formation of keto and hydroxy compounds of linoleic acid in submitochondrial particles of bovine heart.

To observe lipid peroxidation of additive-free submitochondrial particles, we incubated submitochondrial particles in the absence of exogenous irons and t-butyl hydroperoxide. After the incubation, the phospholipids were hydrolyzed by phopholipase A2, and the fatty acid constituents were analyzed by high-performance liquid chromatography, gas chromatography-mass spectrometry, and liquid chromatography-mass spectrometry. Contrary to a commonly accepted theory, lipid peroxidation in the submitochondrial particles did not need the addition of NADH. In the phospholipid constituent fatty acids of the oxidized submitochondrial particles, derivatives of hydroperoxides of linoleic acid such as keto, hydroxy, trihydroxy, and hydroxyepoxy compounds were generated. Lipid peroxidation in the submitochondrial particles was not inhibited by the addition of catalase, superoxide dismutase, hydroxyl radical scavengers, or ethylenediaminetetraacetic acid, but was inhibited by the addition of KCN, antimycin-A, NADH, ubiquinol, deferoxamine mesylate, ascorbic acid, and alpha-tocopherol. The cardiolipin-cytochrome c lipid peroxidation system could mimic the lipid peroxidation of the submitochondrial particles, in terms of linoleic acid products and the inhibitory patterns of radical scavengers and electron transfer chain inhibitors. Thus, lipid peroxidation in the submitochondrial particles seems to be due to phospholipid-hemoprotein lipid peroxidation systems such as the cardiolipin-cytochrome c system.

Animals↗

PubMed1998

Distal sensory axonopathy after sarin intoxication.

A 51-year-old man inhaled sarin during a terrorist attack on the Tokyo subway system and died 15 months later. Neuropathologic examination revealed marked nerve fiber decrease in the sural nerve, moderate nerve fiber loss in the sciatic nerve, and unremarkable dorsal root ganglia, dorsal roots, and posterior column of the spinal cord. This pathology is consistent with dying-back degeneration of the peripheral nervous system and could represent a late sequela of sarin intoxication.

Fatal Outcome↗

PubMed1997

Immunohistochemical detection of human milk components aspirated in lungs of an infant.

We examined an autopsy case of an infant whose cause of death was suspected to be asphyxia due to human breast milk aspiration. In order to demonstrate aspirated milk in the lungs, we conducted immunohistochemical staining using eight antibodies against the components of human milk. Seven of the eight antibodies reacted positively with the substances suspected to be aspirated milk. We concluded that immunohistochemical staining with these antibodies is useful to demonstrate human milk aspiration and provide some keys for detecting the causes of unexpected infant deaths.

Autopsy↗

PubMed1997

Detection of sarin hydrolysis products from sarin-like organophosphorus agent-exposed human erythrocytes.

A sarin-like organophosphorus agent, [bis(isopropyl methyl)phosphonate; BIMP], was synthesized. This agent has the same phosphonate group as sarin and also has the same anti-acetylcholinesterase activity potency as sarin. The ID50 and LD50 values of BIMP in mice after intravenous injection were 3.9 nM and 0.8 mg/kg, respectively. The AChE activities of their red blood cells and brains were dose-dependently reduced by intravenous BIMP. After preparation of experimental BIMP-exposed human red blood cells, BIMP-bound acetylcholinesterase (AChE) was solubilized from erythrocyte membranes, purified by immunoaffinity chromatography, digested with trypsin, and the sarin hydrolysis products bound to AChE were released by alkaline phosphatase digestion. The digested sarin hydrolysis products were subjected to trimethylsilyl (TMS) derivatization and detected by gas chromatography-mass spectrometry. Isopropyl methylphosphonic- and methylphosphonic acids, which are the sarin hydrolysis products, were detected in experimental BIMP-exposed human red blood cells. This new method, which enables sarin's hydrolysis products to be detected in BIMP-exposed erythrocytes, is a useful tool for studying sarin-poisoning victims.

Acetylcholinesterase↗

PubMed1997

Formation of leukotoxin (9,10-epoxy-12-octadecenoic acid) during the autoxidation of phospholipids promoted by hemoproteins.

Myoglobin (Mb) and cytochrome c (Cyt c) are known to promote lipid peroxidation when mixed with certain types of phospholipids. In the presence of phospholipids such as cardiolipin (CL), ferrous Mb and Cyt c were converted to ferric hemoproteins, and autoxidation of the phospholipids and the oxidation of free linoleic acid (LA) added to the reaction mixture were observed. When the reaction mixture comprising 0.01 mM Cyt c, 0.2 mM CL and 0.1 mM LA was incubated, 92.7% of LA was consumed, and the LA products included 2.49 microM 9,10-epoxy-12-octadecenoic acid (leukotoxin) and its isomer which are potent inhibitors of mitochondrial respiration and have toxic effects on cardiac function. Hemoglobin (Hb) could promote almost no lipid peroxidation in the presence of any kinds of phospholipids. The experiments using some scavengers of active oxygen species revealed that tocopherol and ascorbic acid could strongly reduced LA oxidation caused by Cyt c or Mb. As LTx production was also observed when LA was mixed with Fe2+, LTx may be a common product where non-enzymatic lipid peroxidation occurs.

Cardiolipins↗

PubMed1997

Effect of monochlorohydrins of linoleic acid on guinea-pig cardiac papillary muscles.

The hydrogen peroxide (H2O2)-myeloperoxidase system can convert linoleic acid (LA) to monochlorohydrins. LA monochlorohydrins can also be produced when LA monoepoxides are subjected to low pH solutions. We chemically synthesized and purified LA monochlorohydrins and examined their effect on the developed tension of guinea-pig papillary muscles in vitro in terms of both concentration and the duration of exposure. A decrease in muscular tension was observed immediately after addition of LA monochlorohydrins at concentrations of 30, 100, and 300 microM. We also compared the effect of LA monochlorohydrins on muscle tension with those of LA monoepoxides.

Animals↗

PubMed1997

Stress-inducible, murine protein mSTI1. Characterization of binding domains for heat shock proteins and in vitro phosphorylation by different kinases.

We have recently isolated the cDNA for the murine homologue of the stress-inducible phosphoprotein STI1 (also known as IEF SSP 3521 or p60). STI1 was previously shown to be 2-fold up-regulated in MRC-5 fibroblasts upon viral transformation and to exist in a macromolecular complex with heat shock proteins of the HSP 70 and 90 families. By peptide-sequencing we have identified the two heat shock proteins that bind to murine STI1 (mSTI1) as HSC 70 and HSP 84/86. We describe two separate binding regions within mSTI1 for the two heat shock proteins. In the presence of cell extracts, the N-terminal region of mSTI1 binds preferentially to HSC 70, whereas the C-terminal portion of the molecule promotes the binding of HSP 84/86. Heat treatment caused a strong induction of mSTI1 message without affecting the steady-state level of the protein significantly. In addition, heat treatment led to changes in the isoform-composition of mSTI1. pp70(s6k), pp90(rsk), and mitogen-activated protein kinase-activated protein kinase 2 were tested as possible STI1 kinases in vitro using recombinant mSTI1 as a substrate: only pp90(rsk) was able to phosphorylate recombinant mSTI1. In vitro kinase assays using casein kinase II suggest serine 189 to be a likely phosphorylation site in mSTI1.

3T3 Cells↗

PubMed1997

Definitive evidence for the acute sarin poisoning diagnosis in the Tokyo subway.

A new method was developed to detect sarin hydrolysis products from erythrocytes of four victims of sarin (isopropylmethylphosphonofluoridate) poisoning resulting from the terrorist attack on the Tokyo subway. Sarin-bound acetylcholinesterase (AChE) was solubilized from erythrocyte membranes of sarin victims, digested with trypsin, the sarin hydrolysis products bound to AChE were released by alkaline phosphatase digestion, and the digested sarin hydrolysis products were subjected to trimethylsilyl derivatization and detected by gas chromatography-mass spectrometry. Isopropylmethylphosphonic acid, which is a sarin hydrolysis product, was detected in all sarin poisoning, victims we examined and methylphosphonic acid, which is a sarin and soman hydrolysis product, was determined in all victims. Postmortem examinations revealed no macroscopic and microscopic findings specific to sarin poisoning and sarin and its hydrolysis products were almost undetectable in their blood. We think that the procedure described below will be useful for the forensic diagnosis of acute sarin poisoning.

Acetylcholinesterase↗

PubMed1997

Characterization of monoclonal antibody reactive with 10-hydroxy-12(Z)-octadecenoic acid (10-OHODA) and its demonstration in cultured human macrophages.

10-Hydroxy-12(Z)-octadecenoic acid (10-OHODA) has an inhibitory effect on the tension of papillary muscles in isolated guinea-pig hearts. To establish an immunoassay for 10-OHODA a mouse monoclonal antibody (MoAb), YM-1, was produced. In order to evaluate the ability of this MoAb to recognize various 10-OHODA analogs including leukotoxin (9, 10-epoxy-12-octadecenoic acid, LTx), a sensitive enzyme-linked immunosorbent assay (ELISA) was developed using the avidin-biotin complex (ABC). The detection limit for 10-OHODA was as low as 0.5 ng in this system. In order to demonstrate the presence of 10-OHODA in living cells, macrophages derived from the human leukemia cell line THP-1 by adding 160nM phorbol 12-myristate 13-acetate (PMA) were exposed to 95% O2, and 5% CO2 for 24 h. 10-OHODA and other fatty acids were extracted from the exposed macrophages with diethylether after phospholipase A2 treatment. The 10-OHODA content was determined using the new ELISA, and 18.5 ng 10-OHODA was detected in the macrophages exposed to the high oxygen concentration (1 x 10(6) cells).

Animals↗

PubMed1997

Death due to a methane gas explosion in a tunnel on urban reclaimed land.

Studies of four male victims who were killed in an accidental tunnel gas explosion on urban reclaimed land are described. The studies were judicial autopsy examinations to determine the precise causes of death. Two men died of carbon monoxide intoxication, one died of massive brain damage, and the fourth died of drowning. The concentrations of methane in several organs were much lower than the lethal level, whereas those in adipose tissue were relatively high. These findings indicated that a low concentration of methane was almost always present in the atmosphere at the construction site. Recently, coal mine accidents have been decreasing in Japan. However, there is still a possibility of underground explosions or gas leaks in confined spaces other than coal mines. To determine the precise cause of death in such cases, careful autopsies and other examinations should be performed using methods similar to those used in coal mine accidents.

Adult↗

PubMed1997

[Clinicopathological studies of craniocerebral gunshot injuries].

UNLABELLED: Gunshot wounds are rare in Japan because of few regulatory laws against the possession of guns. Nevertheless such wounds are increasing in prevalence these days. Reports on the microscopic findings concerning these intracerebral lesions are fewer than those on the macroscopic findings in the scalp, the skull and the intracranial cavity. In this study we evaluated computed tomographical and histopathological findings in craniocerebral gunshot injuries. CASES: Nine patients with gunshot wounds to the head were presented. All were male and the age ranged from 17 to 66 years. Four were suicides and four were attempted murders and the last one was of unknown etiology. Morphological examination was performed on 5 autopsy cases. The distance of the bullet from the cranial cavity was as follows: long distance, 4 cases; close contiguity, 5 cases. The calibers of the weapons were as follows: 38 mm in 6 cases, 45 mm in 1 case and unknown in 2 cases. RESULTS: CT scans were examined in six cases, which revealed a missile track, hemorrhagic contusion, traumatic subarachnoid hemorrhage and marked tension pneumocephalus. In some cases, CT scan also revealed bony and metallic fragments, some deep within the cranial cavity. In the histopathological study, we found marked swollen brain (brain weight over 1500 mg) and hemorrhagic contusion in the vicinity of the missile track and interhemispheric fissure, and widespread traumatic subarachnoid hemorrhage and intraventricular hematoma. We would like to emphasize especially the remote contusion seen in the distant part of the missile track as well as massive exsudation and hemorrhage around the nerve fiber bundles. Remote contusion was observed in the inferior surface of the fronto-temporal lobes, and bilateral hemorrhagic contusion was seen in the vicinity of the superior longitudinal fissure on CT scans and autopsy findings. In one case, the bullet rotated within the intracranial cavity. In conclusion, nine cases of craniocerebral gunshot injuries were examined, while we also reviewed the medical literature concerning the shearing injury produced by gunshot brain wounds. The head injuries were further delineated by the correlation between autopsy and computerized tomography findings.

Adolescent↗

PubMed1997

[Two cases of personal identification from dental information].

We describe two cases in which unknown bodies were positively identified from dental information and biochemical examination using tooth materials. In one case, a charred body was positively identified with little effort by comparison of antemortem dental records (dental chart and dental X-ray film) with postmortem data. In the other case, although the unknown individual had dental treatment, the police were unable to obtain the antemortem dental records of the victim. We then conducted biochemical analysis of teeth, facilitating personal identification using DNA analysis and age estimation based on aspartic acid racemization. The mutation obtained from the sequence of mtDNA and the genotypes of HLADQ alpha, HPRTB and ABO blood groups including the data for estimated age supported the kinship between the unknown individual and his mother. The data for maternally inherited mtDNA were of great importance in this case, since it was possible to obtain DNA from the mother. Dental identification in one of the most accurate methods of personal identification if suitable antemortem records are available. In the absence of such records, biochemical analysis of teeth also makes it possible to increase the probability of correct personal identification.

Adult↗

PubMed1997

Sequencing mitochondrial DNA from a tooth and application to forensic odontology.

Genetic identification can be complicated by long intervals between the time of death and examination of tissues, and sometimes only bone and teeth may be available for analysis. Several investigators have described the isolation of nuclear DNA from these materials, but all have indicated that the DNA is significantly degraded. Recently, the polymerase chain reaction (PCR) and direct DNA sequencing have enabled rapid and reliable characterization of specific highly polymorphic DNA sequences from different individuals. Above all, mitochondrial DNA sequences offer several unique advantages for the identification of human remains. The isolation of mtDNA from a tooth and the symmetrical PCR amplification and direct DNA sequencing of its most polymorphic regions are reported.

Alleles↗