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Human fetuses at term are large relative to the dimensions of the maternal birth canal, implying that their birth can be associated with difficulties. The tight passage through the human birth canal can lead to devastating outcomes if birth becomes obstructed, including maternal and fetal death. Although macaques have to accommodate similarly large fetuses, relative to their maternal birth canals, it was not known whether macaque mothers face birth difficulties similar to humans. Based on 27 y of demographic data from a semi-free-ranging, closely monitored population of Japanese macaques ( Macaca fuscata ), we found no birth-associated mortality in macaques. This differs from the situation in many human populations. We suggest three nonmutually exclusive hypotheses to explain these observations. i) The macaque fetal skull is similarly flexible as the human fetal skull. ii) The macaque pelvis and connective tissue show greater flexibility during birth. iii) The interplay between macaque pelvic shape and birth dynamics is smoother and incurs fewer complications than in humans., Competing Interests: Competing interests statement:The authors declare no competing interest.

Introduction: Cephalic index (CI), the ratio of head breadth to head length, is widely used to categorise human populations. The aim of this study was to access the impact of anthropometric measurements on the CI of male Japanese university students., Methods: This study included 1,215 male university students from Tokyo and Kyoto, selected using convenient sampling. Multiple regression analysis was used to determine the effect of anthropometric measurements on CI., Results: The variance inflation factor (VIF) showed no evidence of a multicollinearity problem among independent variables. The coefficients of the regression line demonstrated a significant positive relationship between CI and minimum frontal breadth (p < 0.01), bizygomatic breadth (p < 0.01) and head height (p < 0.05), and a negative relationship between CI and morphological facial height (p < 0.01) and head circumference (p < 0.01). Moreover, the coefficient and odds ratio of logistic regression analysis showed a greater likelihood for minimum frontal breadth (p < 0.01) and bizygomatic breadth (p < 0.01) to predict round-headedness, and morphological facial height (p < 0.05) and head circumference (p < 0.01) to predict long-headedness. Stepwise regression analysis revealed bizygomatic breadth, head circumference, minimum frontal breadth, head height and morphological facial height to be the best predictor craniofacial measurements with respect to CI., Conclusion: The results suggest that most of the variables considered in this study appear to influence the CI of adult male Japanese students.

The age, total length (L(T)), head shape and skull shape were investigated for 379 Japanese eels Anguilla japonica sampled in freshwater and brackish areas of the Kojima Bay-Asahi River system, Okayama, Japan, to learn about the differentiation process of head-shape polymorphism. The relative mouth width (ratio of mouth width to L(T)) of A. japonica > 400 mm L(T) collected in fresh water was significantly greater than that of fish collected in brackish water. Growth rates of mouth width and the distance from the snout to the midpoint of the eyes (the ratio of width and distance to age, respectively) were not significantly different between freshwater and brackish-water samples, whereas the somatic growth rate (the ratio of L(T) to age) of freshwater samples was significantly lower than that of brackish-water eel samples. These results suggest that the factors affecting head and somatic growth of A. japonica are not identical. According to these results and feeding patterns in each habitat reported by another study, it is suggested that somatic growth appears to play a significant role in the differentiation process of the head-shape polymorphism in A. japonica, with the slow-growing fish in fresh water becoming broad-headed and the fast-growing fish in brackish water becoming narrow-headed., (© 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.)

Functional magnetic resonance imaging (MRI) studies involve normalization so that the brains of different subjects can be described using the same coordinate system. However, standard brain templates, including the Montreal Neurological Institute (MNI) template that is most frequently used at present, were created based on the brains of Western adults. Because morphological characteristics of the brain differ by race and ethnicity and between adults and children, errors are likely to occur when data from the brains of non-Western individuals are processed using these templates. Therefore, this study was conducted to collect basic data for the creation of a Japanese pediatric standard brain. Participants in this study were 45 healthy children (contributing 65 brain images) between the ages of 6 and 9 years, who had nothing notable in their perinatal and other histories and neurological findings, had normal physical findings and cognitive function, exhibited no behavioral abnormalities, and provided analyzable MR images. 3D-T1-weighted images were obtained using a 1.5-T MRI device, and images from each child were adjusted to the reference image by affine transformation using SPM8. The lengths were measured and compared with those of the MNI template. The Western adult standard brain and the Japanese pediatric standard brain obtained in this study differed greatly in size, particularly along the anteroposterior diameter and in height, suggesting that the correction rates are high, and that errors are likely to occur in the normalization of pediatric brain images. We propose that the use of the Japanese pediatric standard brain created in this study will improve the accuracy of identification of brain regions in functional brain imaging studies involving children., (Copyright © 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Context: Although a life-threatening complication, pulmonary aspiration of gastric contents caused by vomiting or regurgitation during induction of anaesthesia cannot be prevented. It may be prevented if the mouth is placed more inferiorly than the larynx and tracheal bifurcation by the use of head-down tilt and head-neck positioning., Objective: We aimed to determine the head-down tilt required to prevent aspiration in the neutral, simple extension, sniffing and full cervical spine extension (Sellick) positions and to investigate the relationship between pulmonary aspiration and the vertical height of the mouth, larynx and tracheal bifurcation., Design: Observational study., Setting: Operating theatre at Nippon Steel Yawata Memorial Hospital., Patients: Manikins with coloured fluid in the oesophagus and 30 adult volunteers., Interventions: Use of head-down tilt between 0° and 50° in 5° increments in four head-neck positions (neutral, simple extension, sniffing and Sellick)., Main Outcome Measures: Aspiration of oesophageal contents (coloured fluid) from the oesophagus into the trachea and bronchi. Measurement of the mouth-arytenoid angle (manikin and volunteers) and the mouth-carina angle (manikin)., Results: The head-down tilts required to protect both the trachea and bronchi from aspiration were 45°, 35° and 10° in the neutral, simple extension and Sellick positions, respectively, which coincided with the mouth-arytenoid angle in those positions. The maximum tilt used in this study was not adequate to prevent aspiration in the sniffing position. The head-down tilt required to level the mouth with the tracheal bifurcation (mouth-carina angle) protected the bronchi from aspiration but not the trachea., Conclusion: A head-down tilt equal to the mouth-arytenoid angle (levelling the mouth with the larynx) was necessary to completely prevent aspiration. This angle of tilt was within clinically relevant ranges only with the Sellick position.

Research has shown that there is a relationship between increased head circumference and autism spectrum disorders (ASD). This study examined this relationship during the first year of life in subjects with ASD. We compared 280 children with ASD and 609 controls. In the ASD-male group, increases were observed in head circumference from 3 to 12months, in height from 3 to 9months, and in body weight from 3 to 6 and 12months. On the other hand, in the ASD-female group increases in head circumference, in body height, and in body weight were only observed at 3months. After adjusting for height, weight, and age, only the head circumference in the male ASD group was significantly increased from 6 to 9months after birth, reaching a peak at 6months after birth. No difference was found in the female ASD group. Although body overgrowth in the ASD group also started early after birth, the increase in head circumference was more marked than that in body growth. The values of physical measurements in the first year may be useful, minimally invasive parameters for the early detection of autism in combination with observing the timing of certain behaviors such as smiling, eye contact, crawling, pointing, and joint attention., (Copyright © 2010 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

The present paper considers a multidimensional view of the standard for the development process of human fetuses. An efficient method by which to find a multidimensional standard curve for the development process of human fetuses is proposed in which a logistic function with three parameters is utilized as an underlying model and a nonlinear regression method is applied. The proposed method also identifies an approximate prediction region, which can be efficiently applied to diagnose fetal malformation., (2010 John Wiley & Sons, Ltd.)

Maternal effects are widespread and influence a variety of traits, for example, life history strategies, mate choice, and capacity to avoid predation. Therefore, maternal effects may also influence phenotypic plasticity of offspring, but few studies have addressed the relationship between maternal effects and phenotypic plasticity of offspring. We examined the relationship between a maternally influenced trait (egg size) and the phenotypic plasticity of the induction rate of the broad-headed morph in the salamander Hynobius retardatus. The relationship between egg size and the induction of the broad-headed morph was tested across experimental crowding conditions (densities of low conspecifics, high conspecifics, and high heterospecific anuran), using eggs and larvae from eight natural populations with different larval densities of conspecifics and heterospecifics. The broad-headed morph has a large mouth that enables it to consume either conspecifics or heterospecifics, and this ability gives survival advantages over the normal morph. We have determined that there is phenotypic plasticity in development, as shown by an increase in the frequency of broad-headed morph in response to an increase in the density of conspecifics and heterospecifics. This reaction norm differed between populations. We also determined that the frequency of the broad-headed morph is affected by egg size in which larger egg size resulted in expression of the broad-headed morph. Furthermore, we determined that selection acting on the propensity to develop the broad-headed morph has produced a change in egg size. Lastly, we found that an increase in egg size alters the reaction norm to favor development of the broad-headed morph. For example, an equal change in experimental density produces a greater change in the frequency of the broad-headed morph in larvae developing from large eggs than it does in larvae developing from small eggs. Population differences in plasticity might be the results of differences in egg size between populations, which is caused by the adaptive integration of the plasticity and egg size. Phenotypic plasticity can not evolve independently of maternal effects.

Background and Objective: Several algorithms that predict the optimal CPAP have been developed for Caucasian patients with OSA syndrome, but these algorithms do not allow for racial differences in craniofacial anatomy. We investigated whether an equation that included data on craniofacial structure, physique and severity of OSA could more accurately predict the optimal CPAP for Japanese patients with OSA syndrome., Methods: In 170 Japanese patients with OSA syndrome, the optimal CPAP was determined by manual titration during polysomnography. An equation predicting the optimal pressure was derived from anthropometric, polysomnographic and cephalometric data. This equation was validated in another 110 Japanese patients with OSA syndrome., Results: Stepwise multiple regression analysis identified AHI, BMI, mean SaO(2) and a cephalometric parameter: the angle between a line from point B to the menton (Me) and a line from Me to the hyoid bone (H) (BMeH), as independent predictors of optimal CPAP. The following equation was constructed to predict the optimal CPAP: 27.78 + (0.041 x BMeH) + (0.141 x BMI) + (0.040 x AHI) - (0.312 x mean SaO(2)). This equation accounted for 47% of the variance in optimal pressure (R(2) = 0.47, P < 0.0001). The measured optimal pressure and the pressure calculated using this equation were very similar in the other 110 patients with OSA syndrome (9.5 +/- 3.0 and 9.2 +/- 2.1 cmH(2)O, respectively)., Conclusion: Optimal CPAP was more accurately predicted by combining a cephalometric parameter with BMI and polysomnographic data in Japanese patients with OSA, suggesting that craniofacial structure may be important in the pathogenesis of OSA syndrome among Asians.

The primary purpose of this research is to collate, compare, and discuss the presently available data for head and face dimensions among Korean and Japanese ethnic groups. Classification of Korean male and female head and face types is simpler than classification of Japanese subjects. Male groups have more statistically significant morphological differences than females, and Japanese subjects display larger values for head and face measurement categories than Korean subjects. Japanese item values for head and face dimensions show distinct differences between male and female subjects compared to Korean subjects. Japanese male subjects have distinct differences from Korean male subjects and relatively lower values for head and face dimensions as age increases compared to Korean male subjects. Generally, female subjects have no regular tendency according to age compared to male subjects.

Computational models of human anatomy, along with Monte Carlo radiation transport simulations, have been used by Snyder et al. [MIRD Pamphlet No. 5, revised (The Society of Nuclear Medicine, New York, 1978)], Cristy and Eckerman [ORNL/TM-8381/VI, Oak Ridge National Laboratory, Oak Ridge, TN (1987)] and Zubal et al. [Med. Phys. 21, 299-302 (1994)] to estimate internal organ doses from internal and external radiation sources. These were created using physiological data from Caucasoid subjects but not from other races. There is a need for research to determine whether the obvious differences from the Caucasoid anatomy make these models unsuitable for estimating the absorbed dose in other races such as the Mongoloid. We used the cranial region of the adult Japanese male to represent the Mongoloid race. This region contains organs that are highly sensitive to radiation. The cranial region of a physical phantom produced by KYOTO KAGAKU Co., LTD. using numerical data from a Japanese Reference Man [Tanaka, Nippon Acta. Radiol. 48, 509-513 (1988)] was used to supply the data for the geometry of a stylized computational model. Our computational model was constructed with equations rather than voxel-based, in order to deal with as small a number of parameters as possible in the computer simulation experiment. The accuracy of our computational model was checked by comparing simulated experimental results obtained with MCNP4C with actual doses measured with thermoluminescence dosimeters (TLDs) inside the physical phantom from which our computational model was constructed. The TLDs, whose margin of error is less than +/-10%, were arranged at six positions. Co-60 was used as the radiation source. The irradiated dose was 2 Gy in terms of air kerma. In the computer simulation experiments, we used our computational model and Cristy's computational model, whose component data are those of the tissue substitute materials and of the human body as published in ICRU Report 46. The observed absorbed dose values (Gy) at all six points were calculated as the percentage difference between MCNP4C simulation and the TLDs. In our computational model, the average values of all the percentage differences were 6.0+/-4.0% (tissue substitute materials) and 7.6+/-6.6% (ICRU Report 46), respectively. In Cristy's model, the corresponding values were 20.4+/-3.8% (tissue substitute materials) and 21.0+/-4.1% (ICRU Report 46), respectively. Considering the margin of error in the radiation sensitivity of the TLDs, this study validates our computational model as a test object for radiation dosimetry studies.

The aim was to study secular changes in head dimensions of Japanese adult males. The subjects were all of Japanese birth and Japanese ancestry. The age range of the subjects was between 18 and 25 years. Four head measurements were taken: head length, head breadth, head height and head circumference. In addition, stature and body weight were also measured. All measurements were made by one observer (Fumio Ohtsuki) from 1998 to 2001. The present sample was compared with the series taken between 1910 and 1917 of Matsumura (J Fak Sci Imp Univ Tokyo Sec 1 (1925) 1) and the one measured in 1965 of Morita and Ohtsuki (Hum Biol 45 (1973) 151). The present study demonstrated the presence of larger means for head length, head breadth and cephalic index in the current sample than in their predecessors of about 35-85 years ago. Also, the present series displayed larger head circumference than that of the Morita and Ohtsuki series. Using ANOVA, head length and head breath showed significant (p<0.01) differences among all birth-year cohorts from 1978 to 1983 of the current sample. Head height, head circumference and cephalic index did not display significant differences. However, the slope of the regression line indicated that all measurements as well as the cephalic index showed slightly decreasing tendencies during the investigated period. These results suggest that brachycephalization has been occurring for approximately about 35-85 years in adult Japanese males, but the change seems to have become reversed slightly during the period covered by the present sample.

Body sizes at birth are important clinical indicators widely used for evaluation of prenatal growth. Japan had significant socioeconomic improvement around the 1960s, and these environmental changes may influence physiologically prenatal growth. Furthermore, in Japan, measurements of size at birth for birth certificates are weight and height. Thus, we can refer to annual data on weight and height, but not on head and chest circumference at birth. In this study we measured the weight, height, and head and chest circumference at birth among 6,563 Japanese singleton healthy infants, annually in 1962 and 1988, and examined secular trends of these anthropometric measurements. The boys consistently exceeded the girls in all four variables. Birth weight and height increased significantly from the 1960s to '70s, but did not differ between the '70s and '80s in both boys and girls. Secular trends of head and chest circumference were different from them. In both boys and girls, head and chest circumference increased significantly from the '60s to the '70s, but decreased significantly from the '70s to the '80s. No difference of head circumference during the '60s and '80s was found, but the difference of chest circumference was found. Size at birth was likely to increase from the '60s to '70s in Japan. These findings suggest that the environmental changes such as socioeconomic improvements influence the prenatal growth.

G protein beta3 subunit C825T polymorphism, which has previously been studied in association with common disorders in adults such as hypertension and obesity, has been focused upon recently for a possible important role in fetal metabolism. Japanese are characterized by having equal allele frequencies for this polymorphism. In this study, we determined the maternal and infantile genotypes in 342 pairs of normal healthy mothers and their infants, and compared the genotype frequencies with various infantile somatoscopic characteristics converted into SD units according to sex, parity and gestational weeks. We observed an association of the maternal (but not infantile) G protein beta3 subunit 825T allele with reduced head circumference but not with reduced birth weight of the neonate. No association was observed between G protein beta3 subunit C825T polymorphism and various maternal somatoscopic characteristics. Although detailed mechanism of this association requires further research, our results suggest that expression of the beta3 subunit 825T allele in the mother may exert influence on fetal metabolic environment, perhaps through changes in the maternal uterine environment, or on maternal metabolism.

Objective: The purpose of this study is to construct the cross-sectional head circumference growth curves, intended for clinical use, for the Japanese from birth to 18 years of age., Subjects and Methods: Two sets of the national survey data on head circumference and height were utilized for the study: (1) The 1990 data collected by the Japanese Ministry of Health and Welfare on children below 7 years of age (n = 16 621, 8511 males, 8110 females). (2) The 1992-1994 data collected by the Research Institute of Human Engineering for Quality Life on children from 7 to 18 years of age (n = 10 183, 5610 males, 4573 females). We used the LMS method to obtain the 3rd, 10th, 25th, 50th, 75th, 90th and 97th percentile values for each age and gender., Results and Conclusions: The results showed a persistent positive secular trend in head circumference in Japanese children of both genders. Comparison of these data with those of recent Caucasian studies revealed ethnic difference in head circumference, with Japanese having relatively larger head circumference for height as compared with Caucasians.

We studied somatometric measurements of the head and face in Japanese adolescents. We obtained craniofacial measurements of 164 children (82 males and 82 females, from 12 to 14 years of age) from the junior high school in Ayase City (Kanagawa prefecture). In order to have adult data with which to compare, we measured 56 dental students (28 males and 29 females, 20 years of age) from Showa University in Tokyo. We found that head breadth reached adult size at 14 years of age, but, in males, head length increased continuously after 14 years of age. Bizigomatic breadth increased from 12 to 20 years of age. Bigonial breadth had almost completed its growth during adolescence. Face depth grew more slowly than face breadth. From these results, it was clear that craniofacial breadth increased earlier than length. Sexual dimorphism in craniofacial size increased according to age, while sexual difference in the index decreased according to age. A comparison of 3 different generations (40 years ago, 20 years ago, and today) showed brachycephalization and secular change of head breadth and facial measurements. These findings were more evident in females than in males.

The aim of the present study was to evaluate the risk of intrauterine growth delay in the offspring of epileptic mothers and to quantify the risks of intrauterine exposure to antiepileptic drugs (AEDs). Data concerning 870 newborns, prospectively collected in Canada, Japan and Italy, using the same study design, were pooled and analyzed. The overall proportion of newborns whose body weight (7.8%) or head circumference (11.1%) at birth were below the 10th percentile was not increased. However, logistic regression analysis showed that the risk of small head circumference was significantly higher in Italian than in Japanese (RR 4.2; 95% CI: 2.2-8.0) or Canadian children (RR 2.6; 95% CI: 1.1-6.5), and in children exposed to polytherapy (RR 2.7; 95% CI: 1.2-6.3), phenobarbital (PB) (RR 3.6; 95% CI: 1.4-9.4) and primidone (PRM) (RR 4.5; 95% CI: 1.5-13.8). Country was also the only factor affecting low body weight, with Italian children having a higher risk than Japanese (RR 5.2; 95% CI: 2.6-10.4) or Canadian (RR 8.8; 95% CI: 2.0-38.1) children. Due to the small categories, the influence of AED doses and plasma concentrations was studied for each individual AED, without adjustment for the other potential confounding factors. A clear dose-dependent effect was found for PB and PRM in terms of both small head circumference and low body weight, and a concentration-dependent effect for PB in terms of small head circumferences. The size of the difference between the Italian and the other two populations, which is only partially explained by differences in therapeutic regimens, suggests that genetic, environmental and ethnic factors also need to be taken into account when considering possible explanations.

In order to understand the role of Latin adjectives, international anatomical names containing the same adjectives were chosen from among the names of structures in the head and neck: these names were assorted into groups according to the actual meanings of the adjectives. When the Latin adjectives indicated the name of the structure, they signified: belonging to the structure, entering into the formation of the structure, articulating with the structure, transmitting the structure, giving attachment to the structure, or some other relationship to the structure. And, furthermore, the structures that were indicated by the same Latin adjectives might be different. In the Japanese language, those adjectives that have different meanings in other internationally accepted anatomical names were sometimes translated into different words. Because of this, some Japanese anatomical names were more concrete than the corresponding Latin anatomical names. It seemed that compound words and abbreviations, which can be formed easily in the Japanese language, made such expression possible.

We developed a query and analysis system for normal growth measurement of Japanese children on our WWW server using CGI. It has two subsystems. The first shows standard height and standard weight calculated by height. This subsystem can calculate the difference between measured height and the standard along with deviation and the ratio of measured weight to the standard weight. The second shows standard height, weight, head circumference, and chest circumference. This subsystem can calculate differences between the measurements and the standard as well as deviation. Because of the low amount of output required, very short turn-around time was required. This system also allows use of the same interface no matter which brand terminal is used and has wide reusability. This system will save doctors and nurses the difficulty of looking up a child's data, then having to make the calculation. We also compare the merits of CGI and Java.

To construct standard growth curves for Japanese infants of very low birthweight, longitudinal data provided by 47 neonatal centers in Japan were reviewed. Data were collected on the growth of infants admitted to those units during 1986 and 1987 and who survived beyond 3 years of age. A total of 379 singleton infants, who were free of neurological sequelae and appropriate for gestational age, were enrolled. Those whose birthweights were more than 600 g and less than 1,500 g were grouped into nine weight categories separated by increments of 100 g. Data on the increase in weight and head circumference were compiled and analyzed until more than half the infants in each weight category had been discharged from each site. Growth curves of bodyweight and head circumference in the nine groups were constructed using polynomial regression analysis to define the curve of best fit. With increasing prematurity, significant trends of greater weight loss (P < 0.05), longer time to reach the lowest weight (P < 0.01) and a longer time to regain birthweight (P < 0.01) were observed. In addition, there was a significantly higher incidence of chronic lung disease in such groups (P < 0.0001). Growth curves were characterized by the average clinical profiles in each of the nine groups. We believe that these data will be useful in evaluating the growth of very low birthweight infants being cared for in modern neonatal intensive care units in Japan.

Controversy exists regarding possible international and interracial differences in head circumferences of children. We undertook the present study in order to see if there was a difference in head circumference between Japanese and Caucasian children. The subjects consisted of a total of 42,392 Japanese children between 0 and 4 years of age surveyed from 1940 to 1980, and these data were compared with those of American and British children. We conclude that there is a significant ethnic difference in head circumference, as large as one channel of usual percentiles, between Japanese and Caucasian children. The results indicate that smaller head circumference in Japanese children primarily reflects smaller stature of the Japanese.