Do American born Japanese children still grow faster than native Japanese?

Growth patterns of Japanese schoolchildren in Hawaii, composed of 2,954 boys and 3,213 girls aged between 11 and 17, were compared with those comparable groups of Japanese schoolchildren in Japan based on the data published by the Japanese Ministry of Education. Growth characteristics studied were height, weight, and relative weight index, weight/(height). The Hawaii-Japanese boys were taller at early ages but the difference disappeared by age 16. Native Japanese girls were shorter than Hawaii-Japanese until age 13, but they overtook the latter by age 14, exceeding them in height after age 15. A similar pattern was found in weights of girls but the Hawaii-Japanese boys remained consistently heavier by 5.0 to 9.0 kg than native Japanese. The relative weight measure indicated that the Hawaii boys were more "obese" than native Japanese boys for the growth period studied; whereas the same tendency was maintained until age 15 in girls. These observations indicate a marked degree of convergence of the patterns of physical growth of the two populations, whose differences were unmistakably in favor of American born children in earlier studies. It is concluded that the convergence is due largely to the improved environmental conditions in Japan in recent years.     

HIV-1 viral escape in infancy followed by emergence of a variant-specific CTL response

Mutational escape from the CTL response represents a major driving force for viral diversification in HIV-1-infected adults, but escape during infancy has not been described previously. We studied the immune response of perinatally infected children to an epitope (B57-TW10) that is targeted early during acute HIV-1 infection in adults expressing HLA-B57 and rapidly mutates under this selection pressure. Viral sequencing revealed the universal presence of escape mutations within TW10 among B57- and B5801-positive children. Mutations in TW10 and other B57-restricted epitopes arose early following perinatal infection of B57-positive children born to B57-negative mothers. Surprisingly, the majority of B57/5801-positive children exhibited a robust response to the TW10 escape variant while recognizing the wild-type epitope weakly or not at all. These data demonstrate that children, even during the first years of life, are able to mount functional immune responses of sufficient potency to drive immune escape. Moreover, our data suggest that the consequences of immune escape may differ during infancy because most children mount a strong variant-specific immune response following escape, which is rarely seen in adults. Taken together, these findings indicate that the developing immune system of children may exhibit greater plasticity in responding to a continually evolving chronic viral infection.     

Heart rate response to treadmill exercise in children of ages 4-6 years

In order to investigate some characteristics of physical fitness in children, we measured the heart rate of 1069 kindergarten children (aged 4-6 years) and 20 adults during treadmill running. After analyzing the data we obtained the following results: heart rate before, during, and after the running tended to diminish with the increase in age of the subjects in both men/boys and women/girls. The relationship of the heart rates before running and the maximum heart rates during in 25 m run, standing long jump, and softball throw, showed a significant level of 5-0.1% in both boys/men and girls/women. The heart rates of children before, during and after running were higher than those of adults. The rate of increase in heart rate was higher in adults, while more rapid recovery of heart rate was observed in children, when compared to adults.     

Mortality rates in patients with burns; a report of experience at San Francisco City and County Hospital, 1943-1956

A review was made of the cases of 93 patients with burns covering more than 20 per cent of the body surface who were treated at the San Francisco City and County Hospital, University of California Service, between 1943 and 1956. The mortality rate increased from 40 per cent during 1943-1947 to 69 per cent during 1952-1956. A significant change in survival time was noted: During 1943-1947, 69 per cent of the deaths occurred within 48 hours of admission; during 1952-1956, only 19 per cent of the deaths occurred within the first 48 hours. In the period 1943-1947 the majority of deaths resulted from shock in the immediate post-burn period; in the later years of the study the major cause of death was infection. No patient more than 50 years of age who had burns of more than 25 per cent of the body surface survived. Only one patient with burns involving more than 45 per cent survived. No patient who had a blood culture positive for bacteria survived. The use of antibiotics had no effect on the incidence of infection. Elderly patients, children and alcoholics were less able to resist the effects of infection. The lowest mortality rate was in the age group of 15 through 35 years.     

Age-related specificity of the processing of visual information in the system of working memory

In adults and seven- to eight-year-old children, event-related potentials (ERPs) were analyzed during quiet observation and detailed paired comparison of visual stimuli. In both age groups, we showed the differences in the initial stages (component N1) of sensory analysis in these situations. In adults, an increase in the negativity during the initial stages of analysis was observed in the caudal and central areas of the cortex during presentation of standard and test stimuli. In the frontal areas of the cortex, an increase in the negative potential was observed only in ERPs induced by the test stimulus. In children, an increase in the negativity at the initial phases of analysis of stimuli in the situation of working memory, as compared to quiet observation, was confined to the caudal areas of the cortex. Differential curves that characterize analysis of standard and test stimuli showed age-related differences in the initial and late phases of information processing under the conditions of working memory. In adults, the differential curves that characterize analysis of the standard stimulus were represented by negative phases, and the curves related to the test stimulus, by positive phases. In children, late phases of analysis of the standard and test stimuli had smaller differences as compared to adults: the late positive wave was predominant in the responses to both standard and test stimulus in the caudal areas of the cortex. In the frontal areas, there was no considerable increase in the amplitude of the late positive wave in response to the test stimulus. This fact, together with the absence of enhancement of initial negativity in the frontal areas, which reflects analysis of the test stimulus, indicates that the prefrontal cortex plays a smaller role in the comparison of the memory trace with the current information in seven- to eight-year-old children. The data obtained suggest that the central executive of working memory is not sufficiently mature in children aged seven to eight years.     

Children's understanding of dominance and prestige in China and the UK

Individuals can gain high social rank through dominance (based on coercion and fear) and prestige (based on merit and admiration). We conducted a cross-cultural developmental study and tested 5- to 12-year-olds, and adults in the UK and China, aiming to determine (a) the age at which children distinguish dominance and prestige, and (b) the influence of cultural values on rank-related reasoning. We specifically tested participants in China because of the value of prestigious individuals modestly yielding to subordinates, a social skill that becomes more salient with age. In both populations, the distinction between dominance and prestige emerged at five years, and improved over childhood. When reasoning about a resource conflict between a high-ranking party and a subordinate, adults in both countries expected high-rank individuals to win, although Chinese adults were less likely to do so regarding prestigious individuals. Across the two countries, younger children (5–7 years) responded similarly to each other, not favoring either party as the winner. Older children (9–12 years), however, diverged. Those in the UK chose the high-rank party, while those in China made no systematic inference. Overall, our findings suggest that while children distinguish prestige and dominance comparably in the two countries, they develop culturally-influenced expectations about the behavior of high-rank individuals.     

Skeletal maturity of Japanese children in Western Kyushu

This paper describes the skeletal maturity status of Japanese children in Western Kyushu and its variation within Japanese populations. Hand-wrist skeletal maturity was assessed by the Tanner-Whitehouse (1975) (TW2) method from radiographs of 500 boys and 485 girls aged from 4 to 15 years. Western Kyushu children showed retarded skeletal maturity scores (RUS, carpals, and 20-bone) under the age of 12 years for boys and 10 years for girls, and thereafter they were advanced in relation to the British standard. Within Japanese populations the present sample showed delayed maturity compared to Tokyo children, but was close to that of Sapporo children throughout the age range studied. However, the expected effect of secular trend suggested skeletal maturity more advanced for Tokyo children and somewhat advanced one for Sapporo children compared to that of Western Kyushu children.     

MORTALITY RATES IN PATIENTS WITH BURNS—A Report of Experience at San Francisco City and County Hospital, 1943-1956

A review was made of the cases of 93 patients with burns covering more than 20 per cent of the body surface who were treated at the San Francisco City and County Hospital, University of California Service, between 1943 and 1956.The mortality rate increased from 40 per cent during 1943-1947 to 69 per cent during 1952-1956. A significant change in survival time was noted: During 1943-1947, 69 per cent of the deaths occurred within 48 hours of admission; during 1952-1956, only 19 per cent of the deaths occurred within the first 48 hours. In the period 1943-1947 the majority of deaths resulted from shock in the immediate post-burn period; in the later years of the study the major cause of death was infection.No patient more than 50 years of age who had burns of more than 25 per cent of the body surface survived. Only one patient with burns involving more than 45 per cent survived.No patient who had a blood culture positive for bacteria survived. The use of antibiotics had no effect on the incidence of infection. Elderly patients, children and alcoholics were less able to resist the effects of infection.The lowest mortality rate was in the age group of 15 through 35 years.     

Child growth and adult physique in Brazillan Xingu Indians

Data on stature, sitting height, biacromial width, and some other body measurements on 267 children and 363 adults of the Xingu Indians of Brazil have been analyzed. Adult height shows no significant decrease with age over an age range of 20–50 years, thus indicating the absence of secular changes. The average Xingu child seems to be around the twenty-fifth to fiftieth centile for height of British children (if our age estimates are correct) until about ten years in girls and 14 years in boys, but ends at below the third British centile as an adult. In sitting height, however, the Indians show substantially lower values, with children being at about the fifteenth centile until ten years in girls and 14 years in boys, while the adults are considerably below the British third centile. Other comparisons show that the Xingu are taller than Surinam Indians although of similar shoulder width. The lack of anthropometric data concerning South American Indian adults, and more especially children has been stressed. Investigations of these populations facing rapid acculturation and possible assimilation will form a baseline for the future work in public health as contacts with non-Indians increase.     

Impact of pinna compression on the RF absorption in the heads of adult and juvenile cell phone users

The electromagnetic exposure of cell phone users depends on several parameters. One of the most dominant of these is the distance between the cell phone and the head tissue. The pinna can be regarded as a spacer between the top of the phone and the head tissue. The size of this spacer has not yet been systematically studied. The objective of this article is to investigate the variations of distance as a function of age of the exposed person, and the mechanical force on the pinna and how it affects the peak spatial specific absorption rate (psSAR). The distances were measured for adults and children (6–8 years of age) while applying a well‐defined force on the pinna using a custom‐developed measurement device. The average distances of the pinnae to the heads and their standard deviations showed no major differences between the two age groups: 10.5 ± 2.0 mm for children (6–8 years) and 9.5 ± 2.0 mm for adults. The pinnae of our anatomical high‐resolution head models of one adult and two children were transformed according to the measurement results. The numerical exposure analysis showed that the reduced distance due to the pinna compression can increase the maximum 10 g psSAR by approximately 2 dB for adults and children, if the exposure maximum is associated with the upper part of the phone. Bioelectromagnetics 31:406–412, 2010. © 2010 Wiley‐Liss, Inc.     

The development of rhythm regularity, neuromuscular strategies, and movement smoothness during repetitive reaching in typically developing children

IntroductionThis study examined the development of paced coordinated reaching characterized by the successful entrainment of the movement to an external pacer, synchronous muscle activations and movement smoothness.MethodsThirty children, 5–10 years of age, and ten adults were instructed to repeatedly reach for and move an object from a lower shelf to an upper shelf in time to a metronome. Surface electromyography data were recorded. Amplitude and cross-correlations were calculated on three muscle pairs crossing the shoulder and elbow. A motion capture system captured the space curve accelerations of hand, forearm and upper arm segments to quantify movement smoothness.ResultsThe 5–6 year old children showed the greatest amount of temporal variability, followed by 7–10 year olds and then the adults. Correlations between muscle pairs stabilizing the shoulder girdle were higher in each group as compared to the other two muscle pairs but the correlations for all pairs were consistently higher for adults. Movement smoothness for children 9–10 years of age was closer to an adult-like pattern with respect to control of the upper arm, but the hand segment had the greatest variability across groups.ConclusionsThe increased temporal variability and decreased movement smoothness of the hand and forearm segments suggest that control of more distal musculature may be more difficult in children. The neuromuscular strategies adopted by adults were more optimal than those adopted by children as reflected by smoother and more consistent reaching.     

Telocytes and putative stem cells in ageing human heart

Tradition considers that mammalian heart consists of about 70% non‐myocytes (interstitial cells) and 30% cardiomyocytes (CMs). Anyway, the presence of telocytes (TCs) has been overlooked, since they were described in 2010 (visit www.telocytes.com ). Also, the number of cardiac stem cells (CSCs) has not accurately estimated in humans during ageing. We used electron microscopy to identify and estimate the number of cells in human atrial myocardium (appendages). Three age‐related groups were studied: newborns (17 days–1 year), children (6–17 years) and adults (34–60 years). Morphometry was performed on low‐magnification electron microscope images using computer‐assisted technology. We found that interstitial area gradually increases with age from 31.3 ± 4.9% in newborns to 41 ± 5.2% in adults. Also, the number of blood capillaries (per mm²) increased with several hundreds in children and adults versus newborns. CMs are the most numerous cells, representing 76% in newborns, 88% in children and 86% in adults. Images of CMs mitoses were seen in the 17‐day newborns. Interestingly, no lipofuscin granules were found in CMs of human newborns and children. The percentage of cells that occupy interstitium were (depending on age): endothelial cells 52–62%; vascular smooth muscle cells and pericytes 22–28%, Schwann cells with nerve endings 6–7%, fibroblasts 3–10%, macrophages 1–8%, TCs about 1% and stem cells less than 1%. We cannot confirm the popular belief that cardiac fibroblasts are the most prevalent cell type in the heart and account for about 20% of myocardial volume. Numerically, TCs represent a small fraction of human cardiac interstitial cells, but because of their extensive telopodes, they achieve a 3D network that, for instance, supports CSCs. The myocardial (very) low capability to regenerate may be explained by the number of CSCs, which decreases fivefold by age (from 0.5% to 0.1% in newborns versus adults).     

Chewing number is related to incremental increases in body weight from 20 years of age in Japanese middle‐aged adults

doi: 10.1111/j.1741‐2358.2012.00666.x Chewing number is related to incremental increases in body weight from 20 years of age in Japanese middle‐aged adults Background: Eating habits are associated with both current obesity and incremental increases in body weight from young adulthood, but no study has focused on chewing number during meals among community residents. Objective: This study focused on the relationship between chewing number and incremental increases in body weight from 20 years of age. Methods: A total of 93 persons aged 35–61 years participated. The subjects were asked to set the device and record their chewing number during each meal on a particular day. They were also asked whether their body weight had increased by 10 kg or more since they were 20 years old. Results: The body weight of 28 subjects (30%) had increased more than 10 kg since the age of 20 years. Total chewing number showed a relationship with such body weight increases. The odds ratio of weight increments of more than 10 kg for the lowest tertile group was 4.6 [95% confidence interval (CI), 1.3–16.2] relative to the highest tertile group (Model 1). The odds ratio of weight increments for the lowest tertile group increased to 6.3 (95% CI, 1.6–25.4) in Model 2 and to 9.1 (95% CI, 1.7–49.8) in Model 3. Conclusion: Although this study was limited because it did not consider all risk factors, categorical chewing number was related independently to body weight increments of more than 10 kg from 20 years of age.     

Executive functioning in attention-deficit/hyperactivity disorder: questioning the notion of planning deficits with heart rate reactivity

This study employed a paired stimulus paradigm to compare phasic changes in heart rate among children (age categories 6–8, 9–10, and 11–12) and adults (age categories 18–19 and 20–22) with attention-deficit/hyperactivity disorder (ADHD) and age-matched controls. A sample of 95 participants (19 ADHD-diagnosed children, 34 controls, 20 ADHD-diagnosed adults, and 22 controls) solved a planning task, the Tower of London, through 4 levels of difficulty. It was hypothesized that groups with ADHD would show greater heart rate acceleration and less final deceleration than would controls, and that these heart rate responses would change with age and difficulty level as well. Though heart rate differences were found among age categories and difficulty levels, none were found between participants with ADHD and controls. The lack of ADHD differences are not consistent with the behavioral evidence that planning by itself is one of the marked executive function deficits in ADHD. Because ADHD differences were not evident, the effects either were not present or were smaller than that of difficulty level and age. Possible explanations for this lack of difference and future directions are discussed.     

Secular trend in the stature and weight of Mexican-American children in Texas between 1930 and 1970

Statures and weights for four samples of Mexican-American children in Texas, measured in 1929–1931 and 1968–1972, were evaluated for evidence of a secular trend. The age range was 6 to 18 years, with more complete data from 8 through 15 years. There is no secular increase in the statures and weights of 6 year old children, a small increase in 8 years old children, and a larger secular increase at 10, 12, 14, and 15 years of age. From about 9 or 10 years of age on, the more recent Mexican-American children tend to have greater weights for their heights. The magnitudé of the secular change per decade, however, is considerably smaller than rates for US black, white, European, and Japanese children. The estimated rates of secular change in stature for Mexican-American children approximate about one-fourth to one-half of the generalized rates for European and North American children offered by Meredith ('76) and Tanner ('77). Reasons for a limited secular trend in Texas Mexican-American children are probably bound to the matrix of lower socioeconomic circumstances, poorer health conditions, and marginal nutritional status.     

Crayfish co-introduced symbiotic ostracod found on native crab in Japan: The first record of epibiont ostracod found a new host

Ankylocythere sinuosa (Rioja, 1942), a symbiotic ostracod native to North America, was found from the Japanese mitten crab Eriocheir japonica (De Haan, 1835), a species native to Japan, collected from a pond in Shizuoka City, Shizuoka Prefecture, central Japan. Introduced North American crayfish Procambarus clarkii (Girard, 1852), which is a host of A. sinuosa in their native range, inhabits ponds sympatrically with Japanese mitten crabs, and it is thought that the ostracods transferred from the exotic crayfish to the native crabs. In recent years, along with the artificial transportation of crayfish around the world, their symbiotic ostracods also have been found on the body surfaces of exotic crayfish in Europe and Japan. However, no studies have confirmed the infestation of exotic ostracods on native crustaceans in the field. A wide range of developmental stages of A. sinuosa from juveniles to adults were found in Japanese mitten crabs, and mating individuals were also found. This strongly suggests that they can reproduce on the body surface of Japanese mitten crabs. In the future, it will be necessary to strengthen measures against alien species to prevent these exotic symbionts from infestating native ecosystems, and we also need to investigate the exact impact of this symbiont on Japanese mitten crabs.     

The effects of prenatal exposure to Ramadan on stature during childhood and adolescence: Evidence from the Indonesian Family Life Survey

Many pregnant Muslim women fast during the Muslim holy month of Ramadan. A number of studies have reported negative life outcomes in adulthood for children who were prenatally exposed to Ramadan. However, other studies document minimal to no impact on neonatal indicators. Using data from the Indonesian Family Life Survey consisting of 45,246 observations of 21,723 children born to 9771 mothers, we contribute to the current discussion on prenatal exposure to Ramadan by examining the effects on stature (height-for-age Z-scores, weight-for-age Z-scores, and body-mass-index-for-age Z-scores: HAZ, WAZ, and BAZ, respectively) from early childhood to late adolescence (0–19 years of age). We introduce an objective mother’s religiosity indicator to improve the intention-to-treat estimations. Children were classified into three groups based on their mother’s religion-religiosity: religious Muslims, less-religious Muslims, and non-Muslims. Using cluster-robust mother fixed-effects, we found negative effects on stature for children born to religious Muslim mothers. The effects were age-dependent and timing-sensitive. For example, children born to religious Muslim mothers were shorter in late adolescence (15–19 years of age) compared to their unexposed siblings if they were prenatally exposed in the first trimester of pregnancy (HAZ difference = −0.105 SD; p-val. <0.05). Interestingly, we found positive effects on stature for exposed less-religious Muslim children that peak in early adolescence (10–14 years of age) and negative effects on stature for exposed non-Muslim children that occur only in early childhood (0–4 years of age). We nuance our discussion of health and socioeconomic factors to explain these surprising results.     

Genetic diversity and relationships among native Japanese horse breeds,the Japanese Thoroughbred and horses outside of Japan using genome‐wide SNP data

Eight horse breeds—Hokkaido, Kiso, Misaki, Noma, Taishu, Tokara, Miyako and Yonaguni—are native to Japan. Although Japanese native breeds are believed to have originated from ancient Mongolian horses imported from the Korean Peninsula, the phylogenetic relationships among these breeds are not well elucidated. In the present study, we compared genetic diversity among 32 international horse breeds previously evaluated by the Equine Genetic Diversity Consortium, the eight Japanese native breeds and Japanese Thoroughbreds using genome‐wide SNP genotype data. The proportion of polymorphic loci and expected heterozygosity showed that the native Japanese breeds, with the exception of the Hokkaido, have relatively low diversity compared to the other breeds sampled. Phylogenetic and cluster analyses demonstrated relationships among the breeds that largely reflect their geographic distribution in Japan. Based on these data, we suggest that Japanese horses originated from Mongolian horses migrating through the Korean Peninsula. The Japanese Thoroughbreds were distinct from the native breeds, and although they maintain similar overall diversity as Thoroughbreds from outside Japan, they also show evidence of uniqueness relative to the other Thoroughbred samples. This is the first study to place the eight native Japanese breeds and Japanese Thoroughbred in context with an international sample of diverse breeds.     

Nonlinear growth generates age changes in the moments of the frequency distribution: the example of height in puberty

Higher moments of the frequency distribution of child height and weight change with age, particularly during puberty, though why is not known. Our aims were to confirm that height skewness and kurtosis change with age during puberty, to devise a model to explain why, and to test the model by analyzing the data longitudinally. Heights of 3245 Christ's Hospital School boys born during 1927-1956 were measured twice termly from 9 to 20 years (n=129508). Treating the data as independent, the mean, standard deviation (SD), skewness, and kurtosis were calculated in 40 age groups and plotted as functions of age t. The data were also analyzed longitudinally using the nonlinear random-effects growth model H(t)=h(t-epsilon )+alpha, with H(t) the cross-sectional data, h(t) the individual mean curve, and epsilon and alpha subject-specific random effects reflecting variability in age and height at peak height velocity (PHV). Mean height increased monotonically with age, while the SD, skewness, and kurtosis changed cyclically with, respectively, 1, 2, and 3 turning points. Surprisingly, their age curves corresponded closely in shape to the first, second, and third derivatives of the mean height curve. The growth model expanded as a Taylor series in epsilon predicted such a pattern, and the longitudinal analysis showed that adjusting for age at PHV on a multiplicative scale largely removed the trends in the higher moments. A nonlinear growth process where subjects grow at different rates, such as in puberty, generates cyclical changes in the higher moments of the frequency distribution.     

Occurrence of the African subgroup (Ia) of BK polyomavirus in younger Japanese children

BK polyomavirus (BKV) is ubiquitous among humans, usually infecting them asymptomatically during childhood. BKV persists in renal tissue of individuals and their progeny are excreted in urine, particularly in immunocompromised patients. JC virus, another human polyomavirus, has been considered to be transmitted from parents to children during prolonged cohabitation. However, BKV has been supposed to be transmitted not only within but also outside the family. In the present study, to clarify this possibility, we analyzed phylogenetically 35 BKV which were excreted in the urine by Japanese children and adults undergoing stem cell transplantation. Subtypes I, III and IV were detected in 15, two and one children and in 15, one and one adults, respectively. Among 15 subtype I isolates from children, three, four and eight belonged to subgroups Ia, Ib-1 and Ic, respectively. All the three children from whom Ia was detected were less than 9 years old. In contrast in the adults, three subtype I belonged to Ib-1 and the other 12 to Ic. These findings may reflect the recent transmission of BKV Ia strains to Japanese children.