Kei Yoshitome

Okayama University, Okayama, Okayama, Japan

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Publications (19)37.58 Total impact

  • Fumio Moriya, Kei Yoshitome, Satoru Miyaishi
    Forensic Toxicology 01/2014; 32(1). DOI:10.1007/s11419-013-0207-4 · 5.76 Impact Factor
  • Tomomi Shiotsuki, Kei Yoshitome, Fumio Moriya
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    ABSTRACT: The aim of this preliminary study was to establish a simple, rapid method for recovering urine absorbed in disposable diapers in order to test for methamphetamine (MAP) using the Instant-View™ M-1 and Triage® DOA on-site immunoassay devices. A 4-ml aliquot of drug-free artificial urine was absorbed into a disposable diaper (Pampers®) that had been cut into 3 × 3 cm pieces. Further addition of 4 ml of saturated KCl solution to the piece of diaper led to the recovery of substantial amounts (c.a. 2 ml) of fluid sample within 3–5 min. After diluting recovered fluids two-fold with distilled water, both immunoassays showed all samples were negative for all drug classes. After absorption of artificial urine containing 500–5,000 ng/ml of MAP in similar-sized pieces of diaper using the identical processing method, positive results were observed with Instant-View™ M-1 for artificial urine containing 2,000 ng/ml or more of MAP and with Triage® DOA for urine containing 4,000 ng/ml or more of MAP. Diapers dosed with artificial urine containing 500, 2,500, and 5,000 ng/ml of MAP were further examined by gas chromatography–mass spectrometry, with recoveries of MAP of 98.6 ± 36.7 % (n = 6), 115 ± 22.4 % (n = 6), and 102 ± 15.1 % (n = 6), respectively. Use of this new sample preparation method may be applicable for analyzing infant urine absorbed in disposable diapers. Additionally, the sensitivity of the method along with the availability of Instant-View™ M-1 screening suggests the potential usefulness of this technique in clinical settings.
    Forensic Toxicology 07/2012; 30(2). DOI:10.1007/s11419-012-0142-9 · 5.76 Impact Factor
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    ABSTRACT: Methamphetamine (MAP) and stress both cause a variety of cardiovascular problems. Stress also increases stimulant drug-seeking or drug-taking behavior by both humans and animals. In addition to the physiological effects on circulation, metabolism, and excretion, stress affects subject's responses to stimulant drugs such as MAP. However, the mechanisms underlying the drug-stress interactions remain unknown. In the present study, we assessed the effects of stress on myocardial responses to MAP in mice. Mice were injected with MAP (30mg/kg) immediately before exposure to water-restraint stress (WRS), which has often been used as a stressor in animal experiments. The combination of MAP with WRS produced a significant increase (p<0.01) in the leakage of proteins specific to myocardial damage and the levels of cytokines IL-6, TNF-α, and IL-10. The histological findings indicated the possibility that a combination of MAP with WRS induced cardiac myocytolysis. We also examined the expression of heat shock proteins (Hsps), which have cardioprotective effects. Administration of MAP alone significantly stimulated the RNA expressions of Hsp32, 60, 70, and 90 and the protein Hsp70 in cardiac muscles, whereas the expressions due to WRS or MAP plus WRS were not increased. These results reveal the fact that exposure to WRS depresses the induction of Hsps, in particular Hsp70, due to MAP injection, following to enhance MAP-induced myocardial damage. We believe that interactions between MAP and severe stress, including environmental temperature, affect the induction of Hsps, following to susceptibility of hosts to cardiotoxicity due to the stimulant drug.
    Chemico-biological interactions 03/2011; 190(1):54-61. DOI:10.1016/j.cbi.2011.01.025 · 2.98 Impact Factor
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    Kei Yoshitome, Hideo Ishizu, Satoru Miyaishi
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    ABSTRACT: Postmortem acidification of blood and the contribution of this phenomenon to increased flecainide concentrations in cardiac blood were evaluated in rabbits. Flecainide was administered intravenously, antemortem peripheral blood was collected 15 min after administration, then rabbits were sacrificed. Blood and organs were collected immediately or 24 h after death, or immediately or 24 h after performance of cardiac massage. Postmortem left/right cardiac blood and organs showed lower pH than antemortem blood, and flecainide concentrations in all postmortem blood samples were higher than those in antemortem blood. Increased flecainide concentrations in cardiac blood were enhanced by postmortem cardiac massage and postmortem interval. In perfusion experiments using rabbit lung and heart, even if the flecainide concentration in inflow was kept constant, outflow concentrations were 2- to 3-fold higher than in inflow when inflow pH changed from 7.4 to 5.5. In contrast, flecainide concentration in outflow decreased immediately and then remained low when pH of perfusate changed from 5.5 to 7.4. These results demonstrate that flecainide accumulates in the lungs before death, and this accumulated flecainide releases into blood following postmortem acidification of blood/organs.
    Journal of analytical toxicology 01/2010; 34(1):26-31. DOI:10.1093/jat/34.1.26 · 2.63 Impact Factor
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    ABSTRACT: The annual number of suicides in Japan increased sharply in 1998, and since that time it has consistently exceeded 30,000 per year. In this study, we analyze a database of personal and background characteristics of 824 cases (605 men, 219 women) who completed suicide in Okayama Prefecture in 2002 and 2003. The data were obtained with cooperation from the police. Using the methodologies in a previous European study as a model, we classified the suicide methods into 8 categories. To examine the generational and regional differences in the choice of methods, we stratified the sample into 4 age groups (< or =24, 25 approximately 44, 45 approximately 64, and > or =65) and 2 regional groups (Okayama/Kurashiki vs. other areas). Our results on gender differences in 7 of the suicide methods were mostly similar to the European data. However, our data showed a remarkably higher proportionate male-to-female mortality ratio for poisoning by other substances (ICD-10, X65-X69 codes) (1.83, 1.15-2.92). In terms of generational differences in the choice of suicide methods, the Mantel-Haenszel test of homogeneity was significant for most of the categories in our study, suggesting an impact of age on how people commit suicide. There were no remarkable regional differences in our sample. An epidemic curve for suicides via carbon monoxide poisoning using charcoal briquets revealed a trend of time clustering not observed in the other 6 means. The database constructed and used in this study contains richer information than conventional death statistics and is expected to provide helpful knowledge and insights for future epidemiological studies.
    Acta medica Okayama 08/2009; 63(4):177-86. · 0.75 Impact Factor
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    ABSTRACT: We encountered a case of fatal congestive heart failure that occurred under the influence of flecainide. In this case, an extreme postmortem increase in the flecainide level was identified in cardiac blood. The patient had been administered 400 mg/day of flecainide for seven days before death. Antemortem plasma obtained 13 h before death showed a flecainide concentration of 2.5 mg/L and a pH of 7.4. In comparison, centrifuged supernatants of postmortem right and left cardiac blood contained flecainide concentrations of 13.8 and 44.2 mg/L, respectively, with pH of 5.5 in both samples. This increase in blood flecainide concentration was attributed to postmortem redistribution, as about 18 h had passed between the last intake of flecainide and death.
    Journal of analytical toxicology 07/2008; 32(6):451-3. DOI:10.1093/jat/32.6.451 · 2.63 Impact Factor
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    ABSTRACT: The authors encountered a case of hydrochloric acid (HCl) poisoning, thought to be caused by oral ingestion of concentrated HCl. Coagulation of the surface of the tongue and the mucosa of the pharynx, esophagus, and stomach were observed at forensic autopsy. An overabundance of Cl- was found in the gastric contents, corresponding to 8.19 mL of concentrated HCl. This was suggested to be a lethal oral dose of concentrated HCl, and the cause of death was determined to be HCl poisoning. Measuring the pH and concentrations of various ions in body fluids and contents of the alimentary tract enabled postmortem diffusion of HCl to be determined.
    Journal of analytical toxicology 06/2006; 30(4):278-80. DOI:10.1093/jat/30.4.278 · 2.63 Impact Factor
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    ABSTRACT: Zusammenfassung
    Rechtsmedizin 08/2005; 15(4):206-210. DOI:10.1007/s00194-005-0330-6 · 0.63 Impact Factor
  • Rechtsmedizin 01/2005; 15(4):206-210. · 0.63 Impact Factor
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    ABSTRACT: A novel 39-plex typing system for single nucleotide polymorphisms (SNPs) has been developed. This multiplex approach has the advantage of being able to type 38 autosomal SNPs and one sex-discriminating base exchange site on the X and Y chromosomes rapidly and simultaneously. The SNP loci on the autosomes, which we examined, contain 15 loci distributed on blood type genes: three on RhCE, two each on Km and Gc, and one each on Duffy, AcP1, Tf, MN, GPT, EsD, PI, and Kidd genes. Thirty-seven genomic DNA fragments containing a total of 38 SNPs and one sex-discriminating site were amplified in one multiplex PCR reaction. Following the reaction, single nucleotide primer extension reaction was performed by dividing these SNP loci into five groups. The SNP type of each of the 39 loci was determined at one time by capillary electrophoresis using the newly designed multi-injection method. The combined PD (power of discrimination) of this typing system was (1-1.1) x 10(-14), and the MEC (mean exclusion chance) was 0.9990. We applied this system to forensic cases, including 16 paternity testing cases (13 non-exclusion and three exclusion cases) and one personal identification case. For the paternity testing cases, the highest Essen-Möller's W-value was 0.9999995. The pM (matching probability) of the personal identification case was 2.22 x 10(-17). These data showed that this system was an excellent tool for use in forensic cases of paternity testing and personal identification.
    Forensic Science International 09/2004; 144(1):45-57. DOI:10.1016/j.forsciint.2004.03.005 · 2.12 Impact Factor
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    ABSTRACT: We presented an unusual case of negligent homicide by thorax compression, which is the expanded concept of traumatic asphyxia. A 58-year-old man was restrained in the prone position by six prison officers. They were ordered by their superiors to continue restraining him for about 15 min and the victim died. At the forensic autopsy, typical findings of thorax compression with intramuscular hemorrhages on the back and multiple fractures of the ribs were observed. No evidence of neck compression/smothering or other fatal issues likely to occur by chest compression was found. The reconstruction of the scene corresponded exactly with the localization of the injuries found in the victim. This is the first case of death by pure thorax compression without other fatal factors during intentional restraint, in which the force causing the chest compression was distinctly determined by the autopsy and reconstruction.
    Deutsche Zeitschrift für die Gesamte Gerichtliche Medizin 05/2004; 118(2):106-10. DOI:10.1007/s00414-003-0423-2 · 2.60 Impact Factor
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    ABSTRACT: Allele and genotype frequencies for 15 short tandem repeat (STR) polymorphisms--D3S1358, TH01, D21S11, D18S51, Penta E, D5S818, D13S317, D7S820, D16S539, CSF1PO, Penta D, vWA, D8S1179, TPOX and FGA--in a Japanese population were estimated. No deviations of the observed allele frequency from Hardy-Weinberg equilibrium expectations were found for any of the systems studied. Between 2 new pentanucleotide STR loci, Penta E and Penta D, for which there is only limited data regarding the allelic distribution in Japanese, the Penta E locus was found to be highly polymorphic and exhibited a tri- or tetra-modal distribution pattern having allelic peaks with 5, 11, 15 and 20 repeats. The distribution was significantly different from that of the other ethnic groups. Statistical parameters of forensic importance, the power of discrimination (PD), observed and expected heterozygosity values (H), polymorphism information content (PIC), power of discrimination (PD), matching probability (pM), power of exclusion (PE), and typical paternity index (PI), were calculated for the loci. These parameters indicated the usefulness of the loci in forensic personal identification and paternity testing among Japanese. The systems Penta E, FGA, D18S51 and D8S1179 were the most informative. This method was successfully applied to forensic personal identification and paternity testing among Japanese, thereby confirming its efficacy for forensic practice.
    Acta medica Okayama 05/2003; 57(2):59-71. · 0.75 Impact Factor
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    ABSTRACT: We report a case of sudden unexpected death due to rupture of the stomach. A 49-year-old man was found dead in a public lavatory. Autopsy findings revealed two rupture wounds measuring 14 cm and 6 cm located in the fundus of stomach at the side of the greater curvature despite of any superficial injury. The deceased had an ulcer in the lesser curvature of stomach, and dilation in this area was expected to be impaired. Under this condition, excessive over-eating resulting in over-extension of the stomach wall at the greater curvature was speculated to have caused stomach rupture.
    Legal Medicine 04/2003; 5(1):60-4. DOI:10.1016/S1344-6223(02)00034-2 · 1.44 Impact Factor
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    ABSTRACT: We have developed a new method for typing single nucleotide polymorphisms (SNPs) on the human Y chromosome based on a multiplexed single nucleotide primer extension. This method has the advantage that several SNPs are typed rapidly and simultaneously. We examined 15 different SNP loci on Y chromosome, M9, M105, M122, M125, M128, M130, SRY465, IMS-JST006241, IMS-JST006841, IMS-JST002611, IMS-JST003305, IMS-JST008425, IMS-JST021354, IMS-JST021355 and IMS-JST055457, in 159 Japanese males. From the typing results of these 15 loci, we found 13 haplotypes. Gene diversity for each locus ranged from 0.025 to 0.486 and the haplotype diversity was estimated to be 0.838. This method could be readily applied for personal identification and paternity testing.
    Legal Medicine 10/2002; 4(3):202-6. DOI:10.1016/S1344-6223(02)00032-9 · 1.44 Impact Factor
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    ABSTRACT: The difference in the allele frequencies of two single nucleotide polymorphisms (SNPs) in the second exon of the myoglobin gene between Japanese and other populations is reported. These SNPs are the substitutions of (A79G) and (T109C), and they were investigated by a single polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis followed by direct sequencing. The substitutions were always linked and two alleles were found in the samples used: the A-T allele with no substitution at positions (79A) and (109T) and the G-C allele with substitutions of (79G) and (109C). The frequencies of these alleles were 0.755 and 0.245, respectively, and they were found to be in Hardy-Weinberg equilibrium. The distribution of alleles in the Japanese population was significantly different from that reported among whites, blacks, and Hispanics (p < 0.0001).
    Human Biology 04/2002; 74(2):317-20. DOI:10.1353/hub.2002.0025 · 1.52 Impact Factor
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    ABSTRACT: Distribution of Inhaled m-Xylene in Rat Brain and its Effect on GABAA Receptor Binding: Takehiko ITO, et al. Faculty of Education, Okayama University—Organic solvents generally depress the central nervous system (CNS), similarly to volatile anesthetics. The precise mechanism of their action on the CNS, however, is not fully understood, and remains to be clarified. This study is focused on how inhaled m-xylene distributes in the brain, and whether region specific change in GABAA receptor binding takes place due to the exposure. To conduct this study, we first developed a simple exposure system suitable for inhalation experiments with small animals. Using this system, six-week-old male Sprague-Dawley rats were exposed to m-xylene vapor (2000 ppm) 4 h/d, for 5 consecutive days. At the end of the exposure, m-xylene levels in four different regions of the brain were measured by head-space gas chromatography. Also 14 ∝m-thick frozen sections of the brain were made, and (35S) t-butylbicyclophosphorothionate (TBPS) binding autoradiography was performed. Uneven distribution of m-xylene in the brain was observed. The concentration in the cerebellum (976 ± 93.4 ∝g/g tissue) was the highest, while that in the cerebral cortex (467 ± 43.6 ∝g/g tissue) was the lowest. (35S)TBPS binding was significantly greater in the molecular layer of the cerebellum (control: 12.6 ± 0.64, m-xylene 16.0 ± 1.34 fmol/mg tissue). These results suggest that m-xylene is distributed unevenly in the rat brain, and acute exposure to m-xylene at a high concentration alters (35S)TBPS binding, which may reflect changes in GABAA receptor characteristics. (J Occup Health 2002; 44: 69-75)
    Journal of Occupational Health 03/2002; 44(2):69-75. DOI:10.1539/joh.44.69 · 1.10 Impact Factor
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    ABSTRACT: We encountered a rare case of suffocation by an advertising balloon filled with pure helium gas. Suffocation caused by inhalation of atmosphere lacking in oxygen is not exceptional, but reports of death by suffocation due to a pure inert gas such as helium are very rare. In this case, the balloon mooring on the ground was enclosed, warning signs were displayed, and it was clear that entering the balloon filled with an atmosphere lacking in oxygen was extremely dangerous and should not be done; the accident did, however, occur. Accidents of this kind may occur in the future unless appropriate education and countermeasures are taken.
    Acta medica Okayama 03/2002; 56(1):53-5. · 0.75 Impact Factor
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    ABSTRACT: We developed a method for human identification of forensic biological materials by PCR-based detection of a human-specific sequence in exon 3 of the myoglobin gene. This human-specific DNA sequence was deduced from differences in the amino acid sequences of myoglobins between humans and other animal species. The new method enabled amplification of the target DNA fragment from 30 samples of human DNA, and the amplified sequences were identical with that already reported. Using this method, we were able to distinguish human samples from those of 21 kinds of animals: the crab-eating monkey, horse, cow, sheep, goat, pig, wild boar, dog, raccoon dog, cat, rabbit, guinea pig, hamster, rat, mouse, whale, chicken, pigeon, turtle, frog, and tuna. However, we were unable to distinguish between human and gorilla samples. This method enabled us to detect the target sequence from 25 pg of human DNA, and the target DNA fragment from blood stored at 37 degrees C for 6 months, and from bloodstains heated at 150 degrees C for 4 h or stored at room temperature for 26 years. Herein we also report a practical application of the method for human identification of a bone fragment.
    Acta medica Okayama 07/2001; 55(3):175-84. · 0.75 Impact Factor
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    ABSTRACT: In this study, sex determination using polymerase chain reaction (PCR) on tooth material was evaluated from the viewpoint of forensic medicine. The sensitivity of PCR for detection of the Y chromosome-specific alphoid repeat sequence and the X chromosome-specific alphoid repeat sequence was 0.5 pg of genomic DNA. Sex could be determined by PCR of DNA extracted from the pulp of 16 freshly extracted permanent teeth and dentine including the surface of the pulp cavity of 6 freshly extracted milk teeth. Sex could be determined using the pulp in all 20 teeth (10 male and 10 female) preserved at room temperature for 22 years. For the pulp of teeth stored in sea water, the sex could be determined in all 8 teeth immersed for 1 week and in 5 of 6 teeth immersed for 4 weeks. In the remaining 1 tooth, in which sex determination based on the pulp failed, the sex could be determined correctly when DNA extracted from the tooth hard tissue was examined. For teeth stored in soil, the sex could be determined accurately in all 8 teeth buried for 1 week, 7 of 8 teeth buried for 4 weeks, and in all 6 teeth buried for 8 weeks. When teeth were heated for 30 min, sex determination from the pulp was possible in all teeth heated to 100, 150, and 200 degrees C, and even in some teeth heated to 250 degrees C. When this method was applied to actual forensic cases, the sex of a mummified body estimated to have been discovered half a year to 1 year after death could be determined readily by examination of the dental pulp. In the skeletons of 2 bodies placed under water for approximately 1 year and approximately 11 years and 7 months, pulp tissues had been dissolved and lost, but sex determination was possible using DNA extracted from hard dental tissues. These results indicate that this method is useful in forensic practices for sex determination based on teeth samples.
    Acta medica Okayama 03/2000; 54(1):21-32. · 0.75 Impact Factor