Hirotaro Iwase

Stature estimation in Japanese cadavers using the sacral and coccygeal length measured with multidetector computed tomography

We evaluated the relationship between stature and the length of the sacrum and coccyx using multidetector computed tomography (MDCT) and derived regression equations for stature estimation in the modern Japanese population. Two hundred and sixteen Japanese subjects (110 males and 106 females) who underwent postmortem computed tomography with subsequent forensic autopsy between January 2010 and August 2013 were measured. A sagittal-plane image of the sacrum and coccyx was used. Anterior sacral length (ASL) was defined as the linear distance from the anterosuperior edge of the first sacral vertebra (S1) to the anteroinferior edge of the fifth sacral vertebra (S5), and posterior sacral length (PSL) was defined as the linear distance from the posterosuperior edge of S1 to the anteroinferior edge of S5. Anterior sacrococcygeal length (ASCL) was defined as the linear distance from the anterosuperior edge of S1 to the anteroinferior edge of the last coccygeal vertebra (LCV), and posterior sacrococcygeal length (PSCL) was defined as the linear distance from the posterosuperior edge of S1 to the anteroinferior edge of the LCV. The correlation between stature and each parameter was evaluated by simple regression analysis using Pearson product-moment correlation coefficients. Each parameter was significantly and positively correlated with stature among both males and females. Cadaver stature (CS, cm)=0.39×PSL (mm)+123.70 [Corrected] provided the most accurate stature prediction (R=0.507, SEE=5.83 cm) in males. CS (cm)=0.56×PSCL (mm)+85.29 provided the most accurate stature prediction (R=0.659, SEE=6.68 cm) in females. We conclude that sacral/sacrococcygeal length measured with MDCT is a potentially useful tool for stature estimation, particularly in cases where better predictors such as the long bones are not available.

Stature estimation based on radial and ulnar lengths using three-dimensional images from multidetector computed tomography in a Japanese population

The aim of our study was to evaluate correlations between cadaver stature (CS) and radial and ulnar lengths based on three-dimensional (3D) computed tomography (CT) images, and to develop modern regression equations for estimating CS in a Japanese population. Measurements were performed on 245 Japanese subjects (123 males and 122 females) who underwent postmortem CT between May 2011 and December 2013. A 3D reconstructed image was used for assessment. The linear distances of the left radial (LR) and right radial (RR) lengths were measured as a straight-line distance from the most anteroproximal point of the head to the most distal end of the styloid process. The linear distances of the left ulnar (LU) and right ulnar (RU) lengths were measured as a straight-line distance from the most posteroproximal point of the olecranon to the most distal end of the styloid process. The correlation between CS and each parameter (LR, LU, RR, and RU) was assessed using Pearson product-moment correlation coefficients and regression analysis was performed for stature estimation. There were significant correlations between CS and each parameter regardless of sex, indicating that the radial and ulnar lengths measured on 3D CT images can be predictive of stature estimation. Simple regression equations for stature estimation calculated from LR provided the lowest standard error of estimation (SEE) (all subjects, SEE=4.18 cm; males, SEE=4.09 cm; females, SEE=4.21 cm). In addition, multiple regression equations were more accurate and reliable than the single linear regression equations.

Effects of the freezing and thawing process on biomechanical properties of the human skull.

The aim of this study was to determine if biomechanical investigations of skull samples are reliable after skulls have been subjected to a freezing and thawing process. The skulls were obtained from 105 Japanese cadavers (66 males, 39 females) of known age that were autopsied in our department between October 2012 and June 2013. We obtained bone specimens from eight sites (four bilaterally symmetrical pairs) of each skull and measured the mass of each specimen. They were then classified into three groups (A, B, C) based on the duration of freezing of the experimental samples. The left-side samples were subjected to frozen storage (experimental group). The corresponding right-side samples were their controls. Bending tests were performed on the controls immediately after they were obtained. The experimental samples were preserved by refrigeration at -20 °C for 1 day (group A), 1 month (group B), or 3 months (group C). Following refrigeration, these samples were placed at 37 °C to thaw for 1 h and then were subjected to bending tests using a three-point-bending apparatus attached to a Handy force gauge. The device recorded the fracture load automatically when the specimen fractured. Statistical analyses revealed that there were no significant differences in sample fracture loads between the frozen preserved/thawed samples and the unfrozen controls for each of the cryopreservation intervals. We eliminated any possible sample mass bias by using controls from the same skull in each case. The results suggest that the freezing/thawing process has little effect on the mechanical properties of human skulls. Thus, frozen storage for up to 3 months is a good method for preserving human skulls.

Age estimation by quantitative features of pubic symphysis using multidetector computed tomography

Macroscopic assessment of the pubic symphysis is commonly used for age estimation because its surface changes over time. However, postmortem computed tomography (PMCT), a method several forensic medical departments and institutes have begun to adopt, has the potential to simplify the information gathering process from the pelvic bone without requiring soft tissue removal. Some studies have previously evaluated the use of three-dimensional images of the pubic symphysis, but because of variance in the graphics processing among image analysis software packages, certain differences have been observed between these studies. Therefore, in this study, the PMCT findings of 199 subjects of known age and sex were retrospectively reviewed to examine the feasibility of age estimation using planar images of the pubic bones and soft tissue. The coronal and axial sectional images were observed at the center of the symphyseal surface, and the pubic bone length and thickness of the connective tissue of the pubic symphysis were measured at each slice. Our results revealed a significant positive correlation between the length of the pubic bone of the coronal section and age, suggesting that the use of a cutoff value for pubic bone length might be feasible for age estimations. In addition, the thickness of the connective tissue tended to narrow over time. Although the prediction interval range of planar images obtained by PMCT was major and is not usable in practice at this moment, it may still be a useful tool if used in conjunction with other findings obtained by PMCT.

Diagnosis of drowning by summation of sodium, potassium and chloride ion levels in pleural effusion: Differentiating between freshwater and seawater drowning and application to bathtub deaths

Although electrolyte analysis of pleural effusion at autopsy is useful for the diagnosis of water aspiration (i.e., drowning), the method of comparing each level of sodium (Na(+)), potassium (K(+)), and chloride (Cl(-)) ions does not clearly differentiate between freshwater drowning, seawater drowning, and non-drowning. Therefore, here we introduce the summation of Na(+), K(+), and Cl(-) levels, that is SUM(Na+K+Cl), as a modified diagnostic indicator. In 21 autopsy cases of freshwater drowning, 32 cases of seawater drowning, and 43 non-drowning controls (with pleural effusion), mean SUM(Na+K+Cl) differed significantly between the groups (188.8±33.2, 403.5±107.9, and 239.3±21.7 mEq/L, respectively). We defined a SUM(Na+K+Cl) cut-off value of <195.9 mEq/L as strongly suggestive of freshwater aspiration and that of >282.7 mEq/L as strongly suggestive of seawater aspiration. When these values were applied to the two drowning groups, 15 cases (71%) of freshwater drowning and 29 cases (91%) of seawater drowning were diagnosed correctly. This new approach may be more valid than previous methods in cases found >2 days after death or those with substantial pleural effusion (>100 mL). For an additional 15 bathtub deaths, mean SUM(Na+K+Cl) was 198.8±40.0 mEq/L, and in 14 of these cases (93%) the relationship between cause of death and SUM(Na+K+Cl) could be explained using this method. Forensic pathologists should not depend exclusively on chemical findings and should consider also typical pathological indicators of drowning. This new method may be useful as a supplementary diagnostic tool when used alongside consideration of the pathological findings.

Uptake of Shiga-toxigenic Escherichia coli SubAB by HeLa cells requires an actin- and lipid raft-dependent pathway

The novel cytotoxic factor subtilase cytotoxin (SubAB) is produced mainly by non‐O157 Shiga‐toxigenic Escherichia coli (STEC). SubAB cleaves the molecular chaperone BiP/GRP78 in the endoplasmic reticulum (ER), leading to activation of RNA‐dependent protein kinase (PKR)‐like ER kinase (PERK), followed by caspase‐dependent cell death. However, the SubAB uptake mechanism in HeLa cells is unknown. In this study, a variety of inhibitors and siRNAs were employed to characterize the SubAB uptake process. SubAB‐induced BiP cleavage was inhibited by high concentrations of Dynasore, and methyl‐β‐cyclodextrin (mβCD) and Filipin III, but not suppressed in clathrin‐, dynamin I/II‐, caveolin1‐ and caveolin2‐knockdown cells. We observed that SubAB treatment led to dramatic actin rearrangements, e.g. formation of plasma membrane blebs, with a significant increase in fluid uptake. Confocal microscopy analysis showed that SubAB uptake required actin cytoskeleton remodelling and lipid raft cholesterol. Furthermore, internalized SubAB in cells was found in the detergent‐resistant domain (DRM) structure. Interestingly, IPA‐3, an inhibitor of serine/threonine kinase p21‐activated kinase (PAK1), an important protein of macropinocytosis, directly inhibited SubAB‐mediated BiP cleavage and SubAB internalization. Thus, our findings suggest that SubAB uses lipid raft‐ and actin‐dependent, but not clathrin‐, caveolin‐ and dynamin‐dependent pathways as its major endocytic translocation route.

Postmortem dynamic cerebral angiography for detecting aneurysm and bleeding sites in cases of subarachnoid hemorrhage

One of the advantages of postmortem imaging is its ability to obtain diagnostic findings in a non-destructive manner when autopsy is either difficult or may destroy forensic evidence. In recent years, efforts have been made to incorporate computed tomography (CT) based postmortem angiography into forensic pathology; however, it is not currently clear how well the modality can determine sites of bleeding in cases of subarachnoid hemorrhage. Therefore, in this study, we investigated the utility of postmortem cerebral angiography using multi-detector row CT (MDCT) by injecting a contrast medium through a catheter inserted into the internal carotid and vertebral arteries of 10 subarachnoid hemorrhage cases. While postmortem MDCT angiography (PMCTA) was capable of detecting aneurysms in a non-destructive manner, it was sometimes difficult to identify the aneurysm and bleeding sites because of a large amount of contrast medium leaking into the extravascular space. To overcome this problem, we developed the novel contrast imaging method “dynamic cerebral angiography,” which involves scanning the same area multiple times while injecting contrast medium to enable real-time observation of the contrasted vasculature. Using multiphase contrast images acquired by this method, we successfully captured the moment when contrast medium leaked from the hemorrhage site. This method will be useful for identifying exact bleeding sites on PMCTA.

Statistical analysis of biomechanical properties of the adult skull and age-related structural changes by sex in a Japanese forensic sample.

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.

Three-dimensional visualization of composite fillings for dental identification using CT images

OBJECTIVES This study aimed to discriminate between enamel and composite resins by differences in Hounsfield units shown on 16 section multidetector CT (MDCT) images taken of unidentified bodies. METHODS First, we determined the Hounsfield units of composite resins in 15 extracted human teeth. We then filled a single cavity prepared in each of the teeth with one of five different types of composite resins, and scanned the teeth using our routine post-mortem CT protocol for the head and neck. Obtained data were transferred to a radiological workstation and reconstructed. Furthermore, post-mortem CT images of the head of three unidentified bodies were reconstructed in the same manner. RESULTS Four types of composite resins containing radio-opaque fillers showed a constant value of 4000 HU, and one radiolucent composite resin showed values in the range of 660-800 HU in the extracted teeth. Pixels at 4000 HU indicated that the composite resins were selected and visualized as three-dimensional colour images. Composite resins could be visualized on reconstructed images of the three unidentified bodies, and the sites visualized matched those noted on the forensic dental charts. CONCLUSIONS Discriminating enamel and composite resins containing radio-opaque materials was difficult because of their similar Hounsfield unit values. However, we did succeed in visualizing the composite resins despite limitations of the CT scale. CT reconstructed images can contribute to dental identification, particularly in cases where it is difficult to detect composite resins on external investigation, and these images can be prepared during routine dental identification work.

Fatal water intoxication during olanzapine treatment: A case report

A man in his twenties was diagnosed with schizophrenia in his late teens. The night before his death, his family reported he drank a large amount of water, vomited, collapsed, and snored loudly while sleeping, but they did not view the event seriously as he did it routinely. The following morning, he was found dead. Autopsy revealed hyponatremia by water intoxication as the cause of death. Water intoxication has various causes. In this case, 610 ng/mL olanzapine was detected in serum samples. Although this concentration is not as high as the fatal concentrations reported in past studies, it might have caused some adverse effects. Furthermore, the observation that excessive drinking behavior started after the dose of olanzapine was increased suggests a possibility that olanzapine aggravated water intoxication.