Katsura Otsuka

Chiba University, Tiba, Chiba, Japan

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Publications (9)13.92 Total impact

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    ABSTRACT: The purpose of this research was to investigate the biomechanical properties of the adult human skull and the structural changes that occur with age in both sexes. The heads of 94 Japanese cadavers (54 male cadavers, 40 female cadavers) autopsied in our department were used in this research. A total of 376 cranial samples, four from each skull, were collected. Sample fracture load was measured by a bending test. A statistically significant negative correlation between the sample fracture load and cadaver age was found. This indicates that the stiffness of cranial bones in Japanese individuals decreases with age, and the risk of skull fracture thus probably increases with age. Prior to the bending test, the sample mass, the sample thickness, the ratio of the sample thickness to cadaver stature (ST/CS), and the sample density were measured and calculated. Significant negative correlations between cadaver age and sample thickness, ST/CS, and the sample density were observed only among the female samples. Computerized tomographic (CT) images of 358 cranial samples were available. The computed tomography value (CT value) of cancellous bone which refers to a quantitative scale for describing radiodensity, cancellous bone thickness and cortical bone thickness were measured and calculated. Significant negative correlation between cadaver age and the CT value or cortical bone thickness was observed only among the female samples. These findings suggest that the skull is substantially affected by decreased bone metabolism resulting from osteoporosis. Therefore, osteoporosis prevention and treatment may increase cranial stiffness and reinforce the skull structure, leading to a decrease in the risk of skull fractures.
    Forensic science international 10/2013; · 2.10 Impact Factor
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    ABSTRACT: A previously healthy 23-year-old woman was admitted to hospital with abdominal pain at 39 weeks 0 days of pregnancy. The patient suffered sudden cardiopulmonary arrest during the observation and unfortunately died. An autopsy was performed to determine the cause of death. Opening of the peritoneal cavity revealed 2220 mL of blood and a subcapsular hematoma weighing 1060 g on the anterior surface of the right hepatic lobe. A lesion of c. 1 cm in diameter was noted at the center of the front surface of the right hepatic lobe, which was shown on histological examination to be a focal nodular hyperplasia-like lesion. The cause of death was found to be hypovolemic shock caused by bleeding of the rupture of the hepatocellular hyperplastic nodule. Although some previous case reports describe hemorrhage from such lesions, forensic pathologists should be aware that they can lead to severe bleeding and sometimes death.
    Journal of Forensic Sciences 08/2012; · 1.24 Impact Factor
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    ABSTRACT: Personal identification using DNA typing of formalin-fixed tissue is very important in the forensic sciences. However, few studies have been conducted to determine the detection limit of DNA typing of formalin fixation time in samples using the AmpFℓSTR(®) Identifiler(®) PCR Amplification Kit (Identifiler Kit). We collected samples from five cadavers submitted for forensic autopsies, and fixed them either in a 10% formalin solution, or in a 10% neutral-buffered formalin solution. The amount of template DNA for polymerase chain reaction (PCR) amplification and the detection limit of DNA typing for the Identifiler Kit were determined. When tissues were fixed in 10% formalin, 10 ng of DNA template was required for successful genotyping even after three-hour fixation and 100 ng was required after one-week fixation for PCR amplification. However, when tissues were fixed in 10% neutral-buffered formalin, the required amount of DNA template was 1 ng for a fixation time of three hours to three days and 125 ng for three months. Fixation time in neutral-buffered formalin was longer for successful PCR than that in formalin solution. Dropout was more common with increasing formalin fixation time. These results suggest that neutral-buffered formalin is preferred to formalin for fixation of tissues if they are to be subjected to DNA typing and that tissues fixed with neutral-buffered formalin can be used for DNA typing using the Identifiler Kit unless the fixation time exceeds one month.
    Medicine, science, and the law 10/2011; 52(1):12-6. · 0.48 Impact Factor
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    ABSTRACT: Glomerular sclerosis is one of the age-related causes of nephron damage. Histological studies of cadaver kidneys in several ethnic groups have shown that there is a consistent relationship between the percentage of sclerotic glomeruli (PSG) and age. However, no study regarding this relationship in the Japanese population has been reported to date. Here, we investigated such relationship in 150 Japanese cadavers that were selected regardless of clinical history. The straight line regression was estimated as follows: Age=23.3+1.36 x APSG (APSG: arcsine-transformed PSG). The R(2) value of the regression line was 0.598. The diagnostic test with the PSG value (cutoff=0.6%) for the age stratum (cutoff=33 years old) showed very high sensitivity (100%) and specificity (97.6%). From the results, PSG appears to be useful for the estimation of a cadaver's age in the Japanese population.
    Forensic science international 04/2010; 197(1-3):123.e1-4. · 2.10 Impact Factor
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    ABSTRACT: We report two infant deaths attributable to intussusception, but without clear evidence of peritonitis. In the first instance, a 3-year-old girl had presented with abdominal pain, vomiting, and melena before her demise. Aspirated vomitus was subsequently ascertained as the immediate cause of death, due to intussusception-induced ileus. The other infant, a 2-month-old male, showed autopsy evidence of intussusception at two sites, with likely aspiration of gastric mucus. Since the circumstances surrounding his death were vague, timing of the intussusception was difficult to pinpoint. Thus, an inconsequential, agonal event could not be discounted. Taken together, however, death from intussusception, without peritonitis, is the most viable postmortem interpretation for both patients. The causes of death in such cases are established by comprehensive delineation of preceding clinical events, plus autopsy documentation of coexistent intussusception and vomitus aspiration.
    Legal Medicine 03/2010; 12(3):151-3. · 1.08 Impact Factor
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    ABSTRACT: A new method was developed for determining the geographical origin of unidentified cadavers by examining the genome of varicella-zoster virus (VZV), which resides latently throughout life in most individuals and the genotypes which show distinct geographical distribution. VZV DNA samples extracted from the trigeminal ganglia of 62 cadavers (59 from Japan, and 1 each from the United Kingdom, Mongolia, and Pakistan) submitted for medico-legal autopsy were examined. Sequencing was performed on a 358-bp region in the open reading frame (ORF) 22 containing four single nucleotide polymorphisms (SNPs) and a 419-bp region in ORF 62 containing 2 SNPs in the VZV genome. Using these SNP markers, the VZV genome was classified into the nine genotypes described previously. Phylogenetic tree analysis was also undertaken for the sequenced regions and for the 22 existing VZV strains described previously. In addition, 21 samples were subcloned for detection of co-infection. The VZV genome was classified successfully into nine genotypes using four SNPs in ORF 22 and two SNPs in ORF 62 as markers. Among Japanese cadavers, 57 carried genotype J, 1 carried genotype M1, and 1 carried genotype M2. The British and the Mongolian cadavers carried genotype E1 and the Pakistani cadaver carried M1. Phylogenetic tree analysis showed that VZV strains can be classified into different genotypes with high bootstrap values. None of the subcloned samples showed evidence of co-infection. These results suggest that valuable additional information for determining the geographical origin of unidentified cadavers can be provided by examining the VZV genome.
    Journal of Medical Virology 03/2010; 82(5):903-8. · 2.37 Impact Factor
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    ABSTRACT: Investigation of varicella-zoster virus (VZV) is important epidemiologically, and determination of its prevalence rate in human trigeminal ganglia is important to provide surveillance data. To date, studies on VZV detection in trigeminal ganglia have used specimens obtained from a relatively limited number of cadavers. This study attempted to detect VZV DNA as well as Herpes simplex virus type 1 (HSV-1) DNA by the polymerase chain reaction (PCR) from 414 samples of trigeminal ganglia obtained from 207 cadavers selected at random. The detection rate was examined to determine whether there were significant differences in the positive rate between the left and right trigeminal ganglia, males and females, and among age groups. A relationship was found between the positive rates for VZV and HSV-1. VZV DNA was detected in 391 of the trigeminal ganglia (94.4%) and 201 of the cadavers (97.1%) in 121/124 males and 80/83 females. HSV-1 DNA was detected in 251 of the samples (60.6%) and 134 of the cadavers (64.7%) in 72/124 males and 62/83 females. There was no significant difference for either virus in the detection rates between the left and right trigeminal ganglia and males and females. Age and positivity for HSV-1, but not VZV, showed a significant relationship. All 134 cadavers positive for HSV-1 were also positive for VZV. VZV and HSV-1 become latent in bilateral trigeminal ganglia, and are not affected by gender. The prevalence of HSV-1 was greater in advanced age, and the HSV-1-positive rate was correlated with the VZV-positive rate.
    Journal of Medical Virology 02/2010; 82(2):345-9. · 2.37 Impact Factor
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    ABSTRACT: We discuss the usefulness of postmortem computed tomography (PMCT) by reviewing cases of cervical spine injury. A merit of PMCT is that it can identify injury that cannot be found on autopsy; however, peculiar defects of it may exist. While PMCT can identify bone fractures, it cannot indicate whether the injury was inflicted while the deceased was still alive or not because of its inability to clearly image bleeding around the fracture. Furthermore, CT often misses some types of cervical spine injuries, such as laceration of an intervertebral disk and incomplete fracture of the cervical spine. On the other hand, cervical spine injury on CT images occasionally has an appearance similar to subarachnoid hemorrhage due to rupture of the cerebral artery, indicating that cervical spine injury can be misdiagnosed as a disease by PMCT. When PMCT is used for screening trauma, caution must be observed regarding its limitations. If the possibility of trauma of the neck or head is not completely ruled out from the personal history of the victim, autopsy is strongly recommended, even when PMCT findings indicate that the cause of death may be due to disease, such as subarachnoid hemorrhage.
    Legal Medicine 05/2009; 11(4):168-74. · 1.08 Impact Factor
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    ABSTRACT: The DNA of aortic tissues collected at the autopsies of unidentified 47 cadavers was examined using a multiplex short tandem repeat (STR) typing kit. The causes of death included drowning, burning and brain injury among others. Tissues samples were stored in ethanol before DNA extraction. DNA was extracted from about 25mg of dried tissues using a Q1Amp DNA Mini kit (QIAGEN). STR typing was performed using an AmpFlSTR Identifiler PCR Amplification kit (Applied Biosystems) and GeneMapper ID software v. 3.2 (Applied Biosystems). The amount of recovered DNA ranged from 0.006 to 3.44 microg/mg. Tissue samples were collected at estimated times between 1 day and 2 years after death. We were able to type 46/47 tissue samples (98%) and all 15 STR alleles and the amelogenin gene were detected in 38 cases (81%). Successful typing was completed for most tissue samples taken less than 1 month and up until 3 months after death. As the days after death increased, the numbers of alleles with longer DNA fragment sizes decreased. These results suggest that the DNA from aortic tissues can be accurately typed for multiplex STR and amelogenin until about 1 month after death. We found that aortic tissues are one of the most useful samples for forensic personal identification of unidentified bodies.
    Legal Medicine 05/2009; 11 Suppl 1:S455-7. · 1.08 Impact Factor