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Biomedical subjects

S Miyaishi

Publications and source records attributed to S Miyaishi.

At least 19 recordsLinked to original sources

Negligent homicide by traumatic asphyxia.

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.

Asphyxia↗

Fatal hypothermia related vacuolation of hormone-producing cells in the anterior pituitary.

We found small cytoplasmic vacuoles in the hormone-producing cells of anterior pituitary in hypothermic death. The vacuoles were found in approximately 40% of anterior pituitary cells both in males and females that had died from cold (n=31) while the detection rate was lower than 1% (P <0.001) in the other causes of death (n=180: fire death, n=25; fatal injury, n=24; asphyxia, n=24; poisoning, n=8; natural diseases, n=103). The detection rate in hypothermic death was the highest in ACTH cells (about 65%), followed by gonadotrophs (about 43%), and the lowest in TSH cells (about 16%) (P <0.001). These findings suggest that the cytoplasmic vacuoles in the anterior pituitary cells may be the most closely related to cold exposure among the above-mentioned cause of death, providing a supplementary evidence for determining the causes of death.

Adrenocorticotropic Hormone↗

Human identification from forensic materials by amplification of a human-specific sequence in the myoglobin gene.

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.

Amino Acid Sequence↗

Forensic study of sex determination using PCR on teeth samples.

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.

Adult↗

Polymorphism of the D12S391 microsatellite in a Japanese population sample.

Using the polymerase chain reaction (PCR), we studied the short tandem repeat (STR) polymorphism observed at the D12S391 locus. In 350 Japanese examined, 14 different alleles ranging from 209 bp to 261 bp were detected. Allele 18 (221 bp) showed the highest frequency at 0.30. Observed and expected values of respective genotypes satisfied the Hardy-Weinberg equilibrium (chi 2 = 24.08, P = 0.24, df = 20). In addition, 18 additional sequence structures (suballeles), were detected in this study. Within the suballeles, sequence variants, in which the initial repeat of (AGAT) was replaced with (AGGT), was found in five samples. It was found that the analysis of single-strand conformation polymorphism (SSCP) before sequence analysis was useful for distinguishing these suballeles.

Alleles↗

Body-packing as cause of unexpected sudden death.

Four fatalities related to smuggling of drugs by body-packing were investigated. The victims were examined at the Institute of Forensic Medicine of Hamburg University between 1983 and 1995, two of them due to "sudden" unknown cause of death. All victims were male. Two of them were found already dead in a backyard and in a hotel, two other were emergency cases and died at a hospital. Smuggled substances included cocaine (two cases), heroin and amphetamine/caffeine. In all cases, the cause of death was intoxication caused by torn packages which were detected at autopsy. The maximum weight of the packet's contents was 630 g divided in 90 packages. Only one victim was apparently an intravenous drug-abuser. Hair analysis was performed in three cases and revealed in one case a difference between a concealed and a habitually consumed drug. Toxicological analysis revealed that the substances were quite pure and provided evidence that rather long survival was possible following intoxication in three cases, in two cases supported by hospital treatment in the final stage. The procedural regimen in cases of suspected body-packing is discussed.

Adult↗

Haptoglobin genotyping by allele-specific polymerase chain reaction amplification.

We performed haptoglobin (Hp) genotyping by polymerase chain reaction using allele-specific primer-pairs. The major six genotypes of Hp were identified using this method. Among Japanese individuals living in Ehime and Okayama Prefectures, the allele frequencies were estimated to be Hp2 = 0.723 and Hp1s = 0.277. Genotyping of Hp was possible with 0.3 ng of DNA and with 0.125 microliter of blood. It was also possible with whole blood left at room temperature for a month and also with the bloodstains left at room temperature for three years. In the heated blood samples, both alleles, Hp2 and Hp1s, were detected in those heated at 100 degrees C for 2 h. In bloodstains, Hp2 and Hp1s were detected in samples heated at 100 degrees C for 2 h and 120 degrees C for 30 min. In addition, the genotype could be detected in samples other than blood such as saliva, hair roots, tissue sections and dental pulps. The present method for Hp genotyping is expected to become a useful method in forensic analysis.

Alleles↗

Improvement of sensitivity in HLA-DRB1 typing by semi-nested PCR-RFLP.

A sensitive method of HLA-DRB1 typing was devised using a semi-nested polymerase chain reaction (PCR) followed by a restriction fragment length polymorphism (RFLP) analysis (semi-nested PCR-RFLP method). The first-round amplification (30 cycles) of the semi-nested PCR was performed using DRB generic primer pairs and the second round of PCRs (20 cycles) were performed using DRB1 group-specific primers. The products of the second round PCRs were digested with restriction endonucleases for the typing of HLA-DRB1 alleles. By this method, HLA-DRB1 typing was possible from 10 pg of genomic DNA extracted from lymphocytes and from 0.5 microliter of 1,000 times diluted blood without DNA extraction. HLA-DRB1 alleles could be typed from a 2-mm long bloodstained cotton thread prepared from 10 times diluted blood and from a 2-mm thread of whole blood bloodstains stored at room temperature for 2 years. From the mixture of blood of two individuals with different genotypes, DRB1 alleles of the minor component were detected down to 1/1,000 of the major component. This semi-nested PCR-RFLP method is useful for HLA-DRB1 typing from extremely small amounts of DNA and from mixed samples.

Genotype↗

Identification of human skin from tissue fragments left in various conditions using an enzyme immunoassay for squamous cell carcinoma-related antigen.

We investigated the possibility of identification of human skin left under various conditions using our original enzyme immunoassay (EIA) for squamous cell carcinoma-related (SCC) antigen. The antigen could be detected in specimens under the following conditions : purified or dried at room temperature for at least 12 months, immersed in fresh water at room temperature for 3 weeks and heated at 100 degrees C for 72 h.

Antigens, Neoplasm↗

Identification of human skin from a tissue fragment by detection of squamous cell carcinoma-related antigen using an enzyme immunoassay.

A new method of identifying human skin from a tissue fragment by detection of squamous cell carcinoma-related (SCC) antigen, using an enzyme immunoassay, was developed. When an extract was prepared from 0.1 g human skin homogenized with 1 ml of phosphate buffered saline, this method was able to detect SCC antigen in extracts diluted 10(2)-fold. There was no difference in the detection limit between individuals. Species specificity was good, and there was no cross reaction observed with skins from animals. Our method could also discriminate between skin and other organs or tissues, except for esophagus and lung. A practical case to which this method was applied is presented.

Adult↗

[Forensic practice in Hamburg].

The author stayed at the institute of Legal Medicine, University of Hamburg for 10 months from March 1995. The forensic practice in Hamburg was reported in this paper. The annual number of cases treated in this institute are as follows: about 3,000 postmortem inspections, 1,000 autopsies, 170 paternity tests, 4,500 toxicological investigations, 9,000 alcohol determinations and 400 histological investigations. Postmortem inspections and some autopsies are performed in cooperation with "Gerichtsärztlicher Dienst".

Autopsy↗

Identification of menstrual blood by the simultaneous determination of FDP-D dimer and myoglobin contents.

FDP-D dimer (D-D) and myoglobin concentrations in peripheral, menstrual and postmortem blood/bloodstains were determined. The mean plasma concentrations of D-D in peripheral, menstrual and postmortem blood were 0.047, 102 and 220 micrograms/ml and those of myoglobin were 0.028, 0.066 and 727 micrograms/ml respectively. The mean D-D concentration in menstrual bloodstains was about 200 times higher than in peripheral bloodstains. The myoglobin contents in both bloodstains were similar. The mean myoglobin content in postmortem bloodstains was about 4000 times higher than in menstrual bloodstains. By the simultaneous determination of D-D and myoglobin contents, blood or bloodstains containing large amounts of D-D and only a small amount of myoglobin could be identified as menstrual blood.

Blood Specimen Collection↗

Identification of human skeletal muscle from a tissue fragment by detection of human myoglobin using a double-sandwich ELISA.

A method for identifying human skeletal muscle by detection of human myoglobin using a double-sandwich ELISA was developed. When an extract was prepared from 0.1 g skeletal muscle homogenized with 10 ml PBS, this method was able to detect human myoglobin in extracts diluted 10(4)-fold. There was no difference in the detection limit between individuals or sites of origin of skeletal muscles. Species specificity was good and no cross reaction occurred with skeletal muscle from other animals except the gorilla. Our method could also discriminate between skeletal muscle and other organs or tissues except the heart. Human myoglobin could be detected in skeletal muscles under the following conditions: putrefied at room temperature for 5 months, dried at room temperature for 11 months, heated at 100 degrees C for 72 h and immersed in fresh water at room temperature for 6 days. Two practical cases to which this method was applied are presented.

Adult↗

Discrimination between postmortem and antemortem blood by a dot-ELISA for human myoglobin.

A method for discriminating between postmortem and antemortem blood from bloodstains by detection of human myoglobin using a dot-ELISA was devised, and its applicability to forensic practice was investigated. This method exploits the high amount of myoglobin present in postmortem blood in comparison with that in antemortem blood. Our dot-ELISA was able to detect human myoglobin from bloodstains containing more than 10 micrograms/ml myoglobin, the level commonly observed in postmortem blood. Using this method, 10 stains of postmortem blood and 10 of antemortem blood were all identified correctly. A one-year-old stain made of postmortem blood and a stain of bloody fluid obtained from a severely putrefied body 4 months after death were identified as postmortem blood by this method. Two practical cases for which this method was applied are presented.

Adult↗

Presumption of a history of methamphetamine abuse by postmortem analyses of hair and nails: a case report.

By sectional analyses of hair, pubic hair, fingernail and toenail of the descendent who had been a habitual abuser of methamphetamine, the drug was detected in each specimen and the drug concentration in the section containing root was higher than that in the other sections. However, no methamphetamine was detected in the other body fluids and tissues. It was considered that the decedent had used methamphetamine for about 18 months and that the dosage of the drug used for the last 10 days or so was relatively large though he had discontinued injecting the drug for 3-5 days.

Adult↗

The use of mass fragmentography for the detection of tetrodotoxin in human body fluids.

The authors report on a convenient electron impact ionization-mass fragmentographic method for determining the amount of tetrodotoxin (TTX) present in body fluids. To explain this method briefly, the TTX present in body fluids was purified with activated charcoal and transformed into 2-amino-6-hydroxymethyl-8-quinazoline (C9-base) with alcoholic KOH (1%). Then the C9-base was injected into a gas chromatograph-mass spectrometer in the form of trimethylsilyl derivative. In this manner the minimum detectable amount of TTX in body fluids was found to be about 0.01 microgram/g. When this method was applied to sera, urine, and the stomach contents of 2 decedents suspected of puffer fish poisoning, 0.053 microgram/g of TTX was detected in stomach contents of one victim. This new analytic method is simpler and more sensitive than other assay methods and thus is considered useful in forensic work.

Body Fluids↗