Contemporary Japanese Population Research Articles

Age estimation using aortic measurements in a contemporary Japanese population

ABSTRACT At the time of death, estimating the age of unknown human remains is valuable for post-mortem identification. However, no sufficiently reliable methods have been developed to date. This study aimed to investigate the relationship between aortic measurements and age of human remains and to assess the feasibility of age estimation using aortic measurements. Data were collected from 550 Japanese dead bodies (321 male and 229 female subjects), ranging in age from infancy to older adulthood (age 0–97 years). During autopsy, aortic thoracic circumference (ATC) and aortic abdominal circumference (AAC) were measured using a ruler, and the sum of ATC and AAC (STA) was calculated. A simple linear regression analysis using the least-squares method was performed to evaluate the correlation between aortic measurements and age in years and to establish the formula for age estimation using aortic measurements. Additionally, four-parameter logistic curves were created for age estimation. Statistically significant positive correlations were found between age and each aortic measurement. Standard errors of the estimation values using ATC and STA were 9.90–12.27 and 8.88–12.28 years, respectively. The results suggest that age estimation based on aortic measurements is useful for forensic investigation.

Age estimation based on maturation of the medial clavicular epiphysis in a Japanese population using multidetector computed tomography.

To estimate forensic age, the Study Group of Forensic Age Diagnostics of the German Association of Forensic Medicine (AGFAD) has recommended the radiological investigation of the medial clavicular epiphysis (MCE). This study aimed to investigate the relation between the maturation of the MCE and age in a contemporary Japanese population using a standard five-stage system by Schmeling et al. and Kellinghaus substage system. A total of 207 cadavers (128 males, 79 females) of known age and sex that underwent postmortem computed tomography (CT) and subsequent forensic autopsy were obtained. The earliest appearance for stage 3c was 18.1 years in the male subjects and 18.4 years in the female subjects. Our results were consistent with those in previous studies and indicate that stage 3c is crucial for medico-legal processes in evaluating age in various countries. Similar studies on the staging of the MCE using CT images in other populations, particularly in Asians, are required.

The World Health Organization's Healthy Diet Indicator and its associated factors: A cross-sectional study in central Kinki, Japan.

The Healthy Diet Indicator (HDI), which is based on adherence to World Health Organization's (WHO) nutrition guidelines, is used worldwide. In 2015, the WHO updated the Fact Sheet for their recommended healthy diet. We investigated diet quality assessed by the updated HDI (HDI-2015) and factors related to adherence to this diet in a Japanese population. We conducted a cross-sectional study of 1370 participants from 8 workplaces, 1 college, and 2 communities. All participants completed a brief-type self-administered diet history questionnaire. The HDI-2015 assesses 7 components: fruits and vegetables, total fat, saturated fatty acid, polyunsaturated fatty acid, free sugar, dietary fiber, and potassium. Only 6.6% of subjects demonstrated high adherence to HDI-2015 (met ≥6 components), whereas 52.0% demonstrated moderate adherence (4–5 components), and 41.4% demonstrated low adherence (0–3 components). Male sex, older age, and regular physical activity were associated with higher adherence. The contemporary Japanese population has an overall low diet quality as evaluated by the updated HDI score. Improving adherence to healthier dietary patterns may promote better health in Japan.

Dietary patterns among Japanese adults: findings from the National Health and Nutrition Survey, 2012.

Recent studies have analyzed dietary patterns to assess overall dietary habits, but there have been no studies of dietary patterns among the contemporary Japanese population nationwide. The objective of this study was to identify dietary patterns based on consumption of food items among Japanese adults, and to examine whether these dietary patterns were associated with nutrient intake, demographic characteristics, and lifestyle factors. The study population included 25,754 Japanese adults aged 20 years and older registered in the nationwide National Health and Nutrition Survey database in 2012. Dietary patterns were analyzed by factor analysis of 29 food items from the dietary intake survey and household-based semiweighed dietary records. Five dietary patterns were identified: high-bread and low-rice, high-meat and low-fish, vegetable, wheat-based food, and noodle and alcohol patterns. The lowest quartile of factor scores for high-meat and low-fish, wheat-based food, and noodle and alcohol patterns had higher nutrient intakes, and the highest quartile of factor scores for the vegetable pattern had a higher nutrient intake overall (all p<0.01). Dietary pattern scores were associated with demographic and lifestyle factors such as sex, age, region, smoking status, and alcohol intake. Five major dietary patterns among Japanese adults were identified by factor analysis. Dietary pattern scores were associated with differences in nutrient intakes and demographic and lifestyle factors. These patterns were further used for examining the association between Japanese diets and health outcomes.

Determination of sex on the basis of hyoid bone measurements in a Japanese population using multidetector computed tomography.

Sex determination for unidentified human remains is important because the determined sex is usually used as a foundation for the estimation of other biological profiles. This study investigated the sexual dimorphism of the adult hyoid bone and developed discriminant equations to accurately estimate sex in a contemporary Japanese population using measurements on two-dimensional computed tomography (CT) images. The study sample comprised 280 cadavers (140 males, 140 females) of known age and sex that underwent postmortem CT and subsequent forensic autopsy. In accordance with previous studies, seven measurements were performed using two-dimensional CT reconstructed images. Most measurements of males were significantly greater than those of females. The perpendicular length from the most anterior edge of the hyoid body to the line that connects the most distal points of the greater horns of the hyoid and the linear distance between the most lateral edges of the hyoid body most significantly contributed to sex determination. This study demonstrated that discriminant functions on the basis of three measurements provided higher rates of accurate sex classification (93.3-94.6%) than univariate functions. Therefore, the hyoid bone is highly sexually dimorphic in the contemporary Japanese population and may be useful in forensic contexts for sex determination with a high level of accuracy.

Sex assessment based on clavicular measurements in a modern Japanese population using multidetector computed tomography

Accurate sex estimation from unknown human remains is crucial as an integral and foremost step toward individual identification. The aims of this study were to assess sexual dimorphism of the clavicle and develop discriminant equations for sex estimation in a modern adult Japanese population based on clavicular measurements using three-dimensional (3D) computed tomographic (CT) images. A total of 300 cadavers (150 males, 150 females) of known age and sex that underwent postmortem CT and subsequent forensic autopsy were obtained. Four measurements were performed using 3D CT reconstructed images that extracted only bones based on the CT values, as follows: the linear distances between the medial superior margins of the left and right sternal facets to the lateral points of the left and right acromial ends, and the linear distances between the medial superior margins of the left and right sternal facets to the tips of the left and right conoid tubercles. The mean values of all measurements were significantly greater for male subjects than female subjects. Univariate discriminant function analysis (DFA) provided correct sex prediction rates of 88.3–92.2%. Stepwise DFA for the left and right clavicles yielded sex classification accuracy rates of 92.2% and 91.0%, respectively. In conclusion, clavicular measurements using 3D CT images of a contemporary Japanese population may be useful for sex estimation in forensic contexts.

Stature estimation in a contemporary Japanese population based on clavicular measurements using multidetector computed tomography

The aims of this study was to assess the correlation between stature and clavicular measurements in a contemporary Japanese population using three-dimensional (3D) computed tomographic (CT) images, and to establish regression equations for predicting stature. A total of 249 cadavers (131 males, 118 females) underwent postmortem CT scanning and subsequent forensic autopsy between October 2011 and May 2016 in our department. Four clavicular variables (linear distances between the superior margins of the left and right sternal facets to the anterior points of the left and right acromial ends and between the superior margins of the left and right sternal facets to the left and right conoid tubercles) were measured using 3D CT reconstructed images that extracted only bone data. The correlations between stature and each of the clavicular measurements were assessed with Pearson product–moment correlation coefficients. These clavicular measurements correlated significantly with stature in both sexes. The lowest standard error of estimation value in all, male, and female subjects was 3.62cm (r2=0.836), 3.55cm (r2=0.566), and 3.43cm (r2=0.663), respectively. In conclusion, clavicular measurements obtained from 3D CT images may be useful for stature estimation of Japanese individuals, particularly in cases where better predictors, such as long bones, are not available.

Sex determination based on sacral and coccygeal measurements using multidetector computed tomography in a contemporary Japanese population

Abstract Sex determination is an integral and foremost step in determining the identity of an unknown individual. The present study aimed to examine skeletal sexual dimorphism of the sacrum and coccyx using computed tomography (CT) images in a contemporary Japanese population and to derive discriminant function formulae for sex determination. Data were collected from 230 cadavers (115 male and 115 female subjects) subjected to postmortem CT scanning and subsequent forensic autopsy. Seven measurements of the sacrum and coccyx were obtained from CT images of each subject. The measurements were analyzed using descriptive statistics and discriminant function analyses. All except one measurement exhibited statistically significant sexual dimorphism, and the maximum sex determination rate was 83.5% according to discriminant function analyses. The results of this study suggest that discriminant analysis of sacral and coccygeal traits may be useful for the sex determination of skeletal remains in the Japanese population when applied with additional methods, such as morphological trait evaluation of other available bones.

Incidence of three-rooted mandibular first molars among contemporary Japanese individuals determined using multidetector computed tomography.

The purpose of this study was to determine the incidence of three-rooted mandibular first molars in a contemporary Japanese population using multidetector computed tomography (MDCT) and examine whether this characteristic root form may be useful for identification purposes. Prior to their forensic autopsies, we obtained MDCT scans of 365 cadavers (255 males, 110 females) with mandibular first molars on both sides. Altogether, 730 mandibular first molars were examined morphologically on reconstructed CT images, and the incidence of three-rooted molars was recorded. The results were analyzed statistically to determine sex and left-right differences using the chi-square test. In all, 189 (25.9%) of the 730 mandibular first molars had three roots: 79 (31.0%) in the 255 males and 35 (31.8%) in the 110 females. No statistically significant difference was found between the sexes. In the 39 individuals who had unilateral three-rooted mandibular first molars, 7 (17.9%) were on the left side and 32 (82.1%) were on the right side, indicating a statistically significant predominance on the right side. The incidence of three-rooted mandibular first molars in contemporary Japanese individuals was 25.9%, with no statistically significant sex difference, but in the case of unilateral three-rooted teeth, with a statistically significant predominance on the right side. Our study found that Japanese and northeastern Asians have a high incidence of the three-rooted mandibular first molars among individuals of Mongolian origin; this finding may be a useful screening tool for identification of unknown individuals.

Sexual determination based on multidetector computed tomographic measurements of the second cervical vertebra in a contemporary Japanese population

Accurate sex estimation is important in forensic investigation to determine the identity of unknown individuals. The aim of this study was to investigate the accuracy of sex assessment based on measurements of the second cervical vertebra (C2) using computed tomographic (CT) images in a Japanese population and to develop discriminant function formulae. The data were collected from 224 Japanese cadavers (112 male subjects, 112 female subjects) on which postmortem CT scanning and subsequent forensic autopsy were performed. Nine CT measurements of the C2 were performed for CT images of each subject. The measurements were assessed using descriptive statistics and discriminant function analyses (DFA). All of the measurements demonstrated significant sexual dimorphism. Multiple DFA with stepwise variable selection resulted in multivariable models; a five-variable model reached an accuracy rate of 92.9%. Our results suggest that metric analysis based on CT images of the C2 can accurately determine the sex from the human skeletal remains in a contemporary Japanese population and may be useful for sex estimation in forensic anthropology.

Sex estimation based on scapula analysis in a Japanese population using multidetector computed tomography

Accurate sex estimation based on measurements of dimorphic dimensions in human unknown remains is important as the first step toward making individual identification. The purpose of this study was to assess the sexual dimorphism of the scapula and to quantify the accuracy of sex estimation in a contemporary Japanese forensic sample using scapular measurements based on three-dimensional (3D) computed tomographic (CT) images. A total of 218 cadavers (109 males, 109 females) that underwent postmortem CT and subsequent forensic autopsy were used. Ten scapular measurements were performed on 3D CT reconstructed images that extracted only bone data, and were analyzed using descriptive statistics and discriminant function analyses (DFA). All measurements were dimorphic in terms of sex differences. Univariate DFA provided sex classification accuracy rates of 75.7–91.3%. Stepwise DFA yielded sex prediction accuracy rates of 93.1–94.5%. In conclusion, the scapular measurements using 3D CT images of a contemporary Japanese population may be useful for the estimation of skeletal sex in the field of forensic anthropology.

Stature estimation from skull measurements using multidetector computed tomographic images: A Japanese forensic sample

The aim of this study was to assess the correlation between stature and cranial measurements in a contemporary Japanese population, using three-dimensional (3D) computed tomographic (CT) images. A total of 228 cadavers (123 males, 105 females) underwent postmortem CT scanning and subsequent forensic autopsy between May 2011 and April 2015. Five cranial measurements were taken from 3D CT reconstructed images that extracted only cranial data. The correlations between stature and each of the cranial measurements were assessed with Pearson product-moment correlation coefficients. Simple and multiple regression analyses showed significant correlations between stature and cranial measurements. In conclusion, cranial measurements obtained from 3D CT images may be useful for forensic estimation of the stature of Japanese individuals, particularly in cases where better predictors, such as long bones, are not available.

Morphometric analysis of sex differences in contemporary Japanese pelves using multidetector computed tomography

Sex estimation of decomposed or skeletal remains is clearly important in forensic contexts. Recently, contemporary population-specific data has been obtained using multidetector computed tomography (MDCT) scanning. The main purpose of this study was to investigate skeletal pelvic dimorphism in a contemporary Japanese forensic sample and to quantify the accuracy of sex estimation using various pelvic measurements obtained from three-dimensional (3D) CT images. This study used a total of 208 cadavers (104 males, 104 females) of which postmortem CT scanning and subsequent forensic autopsy were conducted between December 2011 and August 2014. Eleven measurements of each pelvis were obtained from 3D CT reconstructed images that extracted only bone data. The measurements were analyzed using descriptive statistics and discriminant function analyses. All except one measurement were dimorphic in terms of sex differences. Univariate discriminant function analyses using these measurements provided sex classification accuracy rates of 62.0–98.1%. The subpubic angle was found to contribute most significantly to accurate sex estimation. Multivariate discriminant functions yielded sex prediction accuracy rates of 63.9–98.1%. In conclusion, the pelvic measurements obtained from 3D CT images of a contemporary Japanese population successfully demonstrated sexual dimorphism and may be useful for the estimation of skeletal sex in the field of forensic anthropology.

720 Low percentage (≤10%) of positive biopsy core (PBC) is not a predictor of lower risk for PSA recurrence in cT1c prostate cancer treated with radical prostatectomy in contemporary Japanese population

720 Low percentage (≤10%) of positive biopsy core (PBC) is not a predictor of lower risk for PSA recurrence in cT1c prostate cancer treated with radical prostatectomy in contemporary Japanese population

Water-Soluble Vitamin Deficiencies in Complicated Peptic Ulcer Patients Soon after Ulcer Onset in Japan

We investigated over time whether contemporary Japanese patients with complicated peptic ulcers have any water-soluble vitamin deficiencies soon after the onset of the complicated peptic ulcers. In this prospective cohort study, fasting serum levels of water-soluble vitamins (vitamins B1, B2, B6, B12, C, and folic acid) and homocysteine were measured at 3 time points (at admission, hospital discharge, and 3 mo after hospital discharge). Among the 20 patients who were enrolled in the study, 10 consecutive patients who completed measurements at all 3 time points were analyzed. The proportion of patients in whom any of the serum water-soluble vitamins that we examined were deficient was as high as 80% at admission, and remained at 70% at discharge. The proportion of patients with vitamin B6 deficiency was significantly higher at admission and discharge (50% and 60%, respectively, p<0.05) than at 3 mo after discharge (10%). In conclusion, most patients with complicated peptic ulcers may have a deficiency of one or more water-soluble vitamins in the early phase of the disease after the onset of ulcer complications, even in a contemporary Japanese population.

Mapping Human Genetic Diversity on the Japanese Archipelago

The Japanese people are one of the most important populations for studying the origin and diversification of East Asian populations. As an island population, the Japanese's path of migration is a long-standing controversy. Archeological evidence suggests that there were at least two waves of migration to the Japanese archipelago in prehistory: the Paleolithic and Neolithic Jomonese as well as the Aeneolithic Yayoiese. However, the contributions of these Jomonese and Yayoiese to the contemporary Japanese population remain unclear. In this article, we provide evidence from human genetics as a new approach to addressing this topic. At the beginning, we introduce the history of human migration to the Japanese archipelago, as well as materials and methods human geneticists use. Subsequently, we tested three distinct population expansion models using evidences from recent human genetic studies on the Japanese, East Asian, and Serbian populations. Finally, we conclude that the contemporary main island Japanese are the result of population admixture of Jomonese, Yayoiese, and Han Chinese, which consists with the Admixture model.

Lead in prehistoric, historic and contemporary Japanese: stable isotopic study by ICP mass spectrometry

Lead concentration and isotopic composition of prehistoric (middle and latest Jomon era, 2000–4500 BP, n=6), historic ( Edo era, 130–400 BP, n=10), and contemporary (died in 1987–88, n=15) Japanese bones, and deciduous teeth from contemporary Japanese children born during 1985–88 ( n=17) were analyzed by inductively coupled plasma mass spectrometry. Lead concentration was lowest in Jomon bones and was higher in rural Edo, contemporary, and urban Edo, in that order. Elevated Pb concentration in historic Edo people, as reported previously, was reconfirmed. The average isotopic ratios ( 207Pb/ 206Pb and 208Pb/ 206Pb) in excavated (prehistoric and historic) bones, contemporary bones, and deciduous teeth were different from each other. The contemporary bones had the least radiogenic composition (mean 207Pb/ 206Pb: 0.879; mean 208Pb/ 206Pb: 2.126) while the excavated bones the most (0.848; 2.098), and teeth intermediate (0.866; 2.111). The comparison with the literature data of isotopic compositions of environmental samples showed that the isotopic composition of the excavated bones was within the range of Japanese ores, rocks and soils, indicating the absence of foreign Pb sources in preindustrialized Japan. That of the contemporary bones was closer to the average gasoline Pb, the use of which had been banned in the late 1970s, than to the Pb in airborne particulate matter or refuse incineration ash of 1980s. The average Pb isotopic ratios in the deciduous teeth was close to the isotopic ratios of Pb in airborne particulate matter and refuse incineration ash. These data indicated that the contemporary Japanese population was exposed to foreign Pb which had different isotopic composition from domestic Pb. Exposure to Pb of foreign origin was particularly evidently recorded in people born before the leaded gasoline ban. The history of human Pb contamination in Japan is discussed based on the present results and other previously published data.