Bone maturation reflects the secular trend in growth

The aim of this study was to compare a series of X-rays from the mid-1990s with another taken in the mid-1980s in order to test the possibility that environmental causes affect the skeletal maturation. The first group of subjects included a total of 1,057 girls and 1, 055 boys participating in a project for Japan and China health research in 1986. The second group of subjects included a total of 382 girls and 629 boys participating in a project for bone mineral density research in 1996. The skeletal maturity score using the Tanner-Whitehouse 2-RUS method was used as the fundamental datum. This score was used to represent each group. The Wilcoxon's rank sum test was applied to examine the significance of the difference between the 1986 and the 1996 groups. The 1996 children had not matured more than the 1986 children; children in both groups reached the given scores at almost the same ages. In girls, there was little difference between the groups at 7 years of age, but it declined from 8 years of age onward. Some apparent differences arose at ages 14 and 15, but ceased by age 16 in girls. In boys, no differences were found in those aged from 7 to 17 years, except for 12-year-olds. We did not detect much of a difference in bone maturation between the 1986 and 1996 groups of children, and no differences in height during the same period. Our findings suggest that bone maturation reflects the secular trend in growth.     

Ancient-to-modern secular changes in Korean stature

Statural growth in human populations is a sensitive indicator of socio-economic well-being, and improvements in socio-economic status are reflected in secular increases in adult height. In the present study, we investigated the statures of historical Korean societies to show how stature changed over time. Applying Fujii's equation, derived from modern Japanese, to the measurement of femora removed from 15th- to 19th-century Joseon tombs, the average heights of Korean adults during the Joseon dynasty were estimated to be 161.1 ± 5.6 cm and 148.9 ± 4.6 cm for males and females, respectively. Plotting statures for successive historical societies against time revealed that Korean heights remained relatively unchanged through to the end of the 19th century, a pattern that differs from that seen in many Western countries in which stature transiently decreases after the Middle Ages. In contrast, a sharp increase in Korean stature was observed at the beginning of the 20th century, similar to trends seen in other nations (although exact timing varies in different countries). There were no accompanying changes of stature sexual dimorphism. The data reported in this study reflect the unique historical experience of Korea; the relative isolation of Joseon society, the late onset of modernization (at the end of the 19th century), and the later occurrence of industrialization (during the 1960s).     

Lipid changes during epididymal maturation in ram spermatozoa collected at different times of the year

The phospholipid and phospholipid fatty acid content of ram spermatozoa decreased during maturation in the epididymis but interpretation of the results was complicated by a possible seasonal factor. Loss of individual fatty acids was selective, resulting in an increase in unsaturation during maturation. Testicular spermatozoa and fluid collected directly into chloroform-methanol contained about 7 times more neutral lipid fatty acid than testicular spermatozoa collected for 6--18 h, separated from the rete testis fluid and then extracted; the difference was not due to lipid in the rete testis fluid. Thin-layer chromatography indicated that cholesterol esters and triglycerides were the neutral lipids which were not lost during collection. Epididymal spermatozoa contained only slightly less neutral lipid fatty acid than continuously collected testicular spermatozoa.     

Age-related changes and secular trends in hand bone size

The aim of the present study was to evaluate age- and sex-related changes in the size and shape of long hand bones in a large Chuvashian cohort using cross-sectional and longitudinal study designs. The data were gathered in 1994 (557 individuals) and 2002 (513 individuals). The latter sample included 260 individuals that were studied only during the second expedition, and 253 individuals who were previously investigated in 1994. Statistical analyses included a maximum likelihood-based model-fitting technique and a t-test comparison. We found evidence for secular trend of hand bone size in both males and females within the Chuvashian population. In males, the length and total area of the long hand bones were greater in younger individuals, but mid-shaft bone width remained almost the same in individuals born at different periods of the last century. In females, the length of the hand bones and total bone area remained unchanged in women born after 1937. However, bone mid-shaft width gradually decreased in women born after 1940. Therefore, we argue that, at least within the Chuvashian population, there is a secular trend towards a more gracile appendicular skeleton in both males and females.     

The secular trend in human physical growth: a biological view

Nutritionists and anthropometric historians alike are familiar with the secular trend-height and weight in adults, and the rate of physical development in children, increasing since at least the mid 19th century. The social conditions which drive this trend are of interest to anthropometric historians, but the underlying biology is also important. Here the trends for height, weight and menarcheal age are summarised and contrasted. In Northern Europe, adult height has largely stabilised, and the age of menarche has also settled at around 13 years, while weight continues to increase due to obesity. The increase in height from one generation to the next occurs mainly in the first 2 years of life, due to increases in leg length. The height trend has lasted for 150 years or more, i.e. for six generations, because the rate of catch-up from one generation to the next is biologically constrained to avoid the cost of too rapid catch-up.     

Anthropometric evidence of exogamy related to secular changes in presentday populations

It is shown that subjects born from marriages between individuals from different localities have a longer and narrower head, as well as a greater stature, than individuals whose parents were born in the same commune. The distance between the parents' birthplaces acts in the same way as the increasing size of the locality. Such results demonstrate that exogamy, in the widest meaning of the term, leads to cephalic and statural modifications of the same kind as those recorded for about a century among present day populations of western Europe.     

Some aspects of secular changes in Hungary over the twentieth century

Growth and maturation are considered the most reliable indicators of health status. Their progression rates in turn are strongly influenced by nutrition and socio-economic status, a well-documented relationship. The pattern of the so-called positive secular changes, i.e. the increase in size and earlier maturation, fits the populations' historical model of economic development very well. The historical, political and economic changes occurring in this century in Hungary have had a remarkably strong impact. Until World War I Hungary was an agrarian part of the Austro-Hungarian monarchy, its ethnic composition was most variegated. Both World Wars caused fundamental changes, namely in respect of post-war Hungary they were associated with marked territorial losses and considerable population mobility. In interpreting the developmental differences in the data collected before and after these wars one should take account of the important facts that, in addition to the changes in socio-economic conditions, affected the gene pool of the populations in Hungary. Over the past 100 years profound changes have occurred in the mean body size, growth rate and timing of maturation of the country's population. This paper is a brief analytic summary of the tendencies observed in adult stature, maturation and some socio-economic conditions. It also compares the cohorts of sub-populations as reflected by the reviewed reports. In summarizing the change in adult stature estimated by the data on recruits, soldiers and students of higher education, it could be stated that adult mean stature had become markedly taller in Hungary since the end of the fifties. However, any estimation of the absolute increment and the exact rate is severely biased by the variable character of the samples' representativeness. Similar problems arose in dealing with sexual maturation, because the retrospective and status-quo methods of assessment were found incomparable. Nevertheless, menarche was observed to have shifted to an appreciably younger age lately, a trend that by the end of the 20th century seemed to have reached a more or less stable level.     

Growth reference centiles and secular changes in Turkish children and adolescents

The purpose of the study is to develop current reference growth centiles for Turkish children and adolescents. A cross-sectional growth survey was conducted on 1.427 (709 boys and 718 girls) healthy schoolchildren aged 6-17 years in Ankara, the capital city of Turkey. As an indicator of socio-economic status, the occupation of the parents was recorded. Growth references of height, weight, body mass index (BMI), sitting height, iliospinal height, relative iliospinal height and relative sitting height were constructed by the LMS method. Sex differences, association of parental occupation with height and BMI standard deviation scores were assessed by analyses of variance. Results showed significant sexual dimorphism for height, weight, sitting height and iliospinal height (p<0.001). Significant effect of socio-economic background was found on height and BMI. The prevalence of overweight and obesity was found using the International Obesity Task Force (IOTF) reference criteria 22.4% and 5.6% in boys and 21.2% and 3% in girls. Present results demonstrated an increment during the last three decades in height, leg length and weight curves which is more prominent in boys, but not in the sitting height. This positive secular change appears to be a logical outcome of the gradual changes in nutrition, health care and education, and environmental and economic conditions.     

A natural fluorescent protein that changes its fluorescence during maturation

The gene of a new red fluorescent protein zoan2RFP from a coral polyp Zoanthus sp., a homologue of the known green fluorescent protein from the Aequorea victoria jellyfish, was cloned. At early maturation stages, zoan2RFP exhibits a green fluorescence, which then turns into the red one. A similar phenomenon was recently reported for the E5 mutant of the red fluorescent coral protein DsRed. Zoan2RFP differs from E5 by faster maturation kinetics and the complete disappearance of green fluorescence in the mature protein. Naturally occurring proteins of this type can be considered as intermediate forms between the green and red fluorescent proteins, which are formed during the microevolution of fluorescent proteins.     

Some secular changes in body height and proportion of Japanese medical students

Anthropometric dimensions of 738 medical students at Kyushu University in Japan were analyzed to determine secular changes of height and body proportions during a 20-year period. Since 1961, means of standing height, leg length, and ratio of leg length to standing height have increased, although the rate of increase from 1971 to 1981 has been rather slow. On the contrary, the mean sitting height X 100/standing height has declined during this same period. Compared with data on the Japanese general population, the medical students were considerably taller, but the difference has decreased.     

Some secular changes in the growth of American-born and native Japanese children

Three hundred and sixteen (35%) of the American-born Japanese children whose height, weight, and skeletal age were recorded in 1956–57 were reexamined as young adults between 1968 and 1974, when they were found to be taller, heavier, and shorter legged than men and women in Japan who were born in the same years as they. These differences between the American-born and the native Japanese adults were relatively smaller than they had been during childhood, due to both an acceleration in the growth rate of the native Japanese and a concomitant decline in that of the American-born Japanese during the intervening years. A comparison of our 1956–57 data with Kondo and Eto's findings in Los Angeles in 1971 shows that there has been very little increase in the size of California-Japanese children since 1956. The curves of average heights of native Japanese children 6 to 20 years of age, at 10-year intervals from 1900 to 1970, disclosed the changing rate at which they grew during different decades of that period. Those curves and other data discussed in this paper provide additional evidence of the biological superiority of the human female as compared with the male.     

Developmental changes in keratin patterns during epidermal maturation

The biochemical maturation of the epidermis of Xenopus laevis was examined through an identification of the keratins expressed at selected stages of development. The keratin patterns obtained were compared to those observed in the adult epidermis and two Xenopus non-epidermal, epithelial cell lines. The keratins expressed during development can be grouped into three classes: (1) keratins which are restricted to the embryonic epidermis (58 and 59 kDa); (2) keratins which are prominent during development, but become minor components of the adult epidermis (47, 48, and 60 kDa); and (3) keratins which accumulate during development to become the major keratins of the adult epidermis (49, 53, 56, and 63 kDa). The embryo-specific keratins are present at all developmental stages prior to metamorphosis which we have investigated, but disappear when the epidermis keratinizes during metamorphosis. Both class 1 and 2 keratins, while undetectable or minor components of the adult skin, are present in the two non-epidermal cell lines. In contrast, the class 3 keratins show little overlap with the keratins of these cell lines. All of the class 3 keratins appear after hatching with the exception of the 53-kDa keratin which is present at the earliest developmental stage which we have examined. All of the major keratins of the adult epidermis accumulate as metamorphosis proceeds, while the embryo-restricted keratins are gradually lost.     

A chaperone for ribosome maturation

The nascent pre-rRNA of eukaryotic ribosomes is fully transcribed and assembled into an 80-90 S nucleolar particle before being cleaved into mature ribosomal RNA. The interdependence of steps in the processing of this precursor RNA indicates that RNA processing, at least in part, acts as a quality control mechanism that helps ensure that only functional RNA is incorporated into mature ribosomes. In search of structural components that underlie this interdependence using the Schizosaccharomyces pombe internal transcribed spacer 1 (ITS) as a ligand for affinity chromatography of ITS1-specific proteins, we have isolated a large spliceosome-like protein complex, a ribosome assembly chaperone (RAC) of 20 or more polypeptides (Lalev, A. I., Abeyrathne, P. D., and Nazar, R. N. (2000) J. Mol. Biol. 302, 65-77). When the ITS2 spacer was used in the present study to isolate ITS2-specific proteins, the same proteins were identified consistent with a complex containing multiple specific binding sites. Subsequent competition binding studies indicated that the protein complex actually contains independent binding sites for all four of the transcribed spacers in the pre-rRNA. Because disruption of protein-binding sites in these spacer RNAs is known to severely affect rRNA processing, taken together these results suggest that the RAC complex is a chaperone for ribosome maturation acting as a "rack" on which critical structure is organized.     

Comparative investigation on spindle behavior and MPF activity changes during oocyte maturation between gynogenetic and amphimictic crucian carp

The spindle behavior and MPF activity changes in the progression of oocyte maturation were investigated and compared with cytological observation and kinase assay between gynogenetic silver crucian carp and amphimictic colored crucian carp.MPF activity was measured by using histone H1 as phosphorylation substrate.There were two similar oscillatory MPF kinase activity changes during oocyte maturation in two kinds of fishes with different reproductive modes,but there existed some subtle difference between them.The subtle difference was that the first peak of MPF kinase activity was kept to a longerlasting time in the gynogenetic silver crucian carp than in the amphimictic colored crucian carp.It was suggested that the difference may be related to the spindle behavior changes,such as tripolar spindle formation and spindle rearrangement in the gynogenetic crucian carp.