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Postnatal Growth (postnatal + growth)
Terms modified by Postnatal Growth Selected AbstractsSpatiotemporal Localization of VEGF-A Isoforms in the Mouse Postnatal Growth PlateTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 1 2008Kristin D. Evans Abstract Vascular endothelial growth factor (VEGF) is implicated as a key angiogenic factor in the development of endochondral long bone. Several studies have evaluated the role of VEGF in prenatal endochondral bone development, but few have evaluated VEGF postnatally. Growth plates from mice at postnatal ages 14 (P14), 35 (P35), 49 (P49), and 77 (P77) days were examined for differential expression of the primary VEGF-A mRNA isoforms: VEGF 120, VEGF 164, and VEGF 188. VEGF 120 isoform expression was stable across all ages, whereas VEGF 164 had significantly less expression at P35 and P49 and VEGF l88 expression increased with increasing age. The proportion of transcript isoforms expressed at a given age also changed with VEGF 120 being expressed more highly at P35 and P49 than the other two isoforms. Changes in VEGF mRNA isoforms across cell types within the growth plate were assessed by Percoll fractionation of growth plate cells at age P28. Cells of the proliferative and early hypertrophic regions had significantly higher total VEGF mRNA expression relative to the resting and late hypertrophic regions. VEGF protein expression assessed by immunohistochemistry showed variable expression patterns with increasing postnatal age. In contrast, FLK-1 (VEGF Receptor-2) expression was restricted to the hypertrophic region. These results indicate that VEGF continues to play a significant role in endochondral bone development throughout the entire growth phase of postnatal bone development. Anat Rec, 291:6,13, 2007. © 2007 Wiley-Liss, Inc. [source] Abnormal fetal aortic velocity waveform and postnatal growthACTA PAEDIATRICA, Issue 11 2000D Ley Postnatal growth from birth up to 7 y of age was evaluated in 151 children with varying degrees of intrauterine growth retardation who were previously examined in their intrauterine life with Doppler velocimetry of the thoracic descending aorta. The children with abnormal fetal aortic blood flow class (BFC), of which 39/46 (85%) had a birthweight 2 SD below the mean of the population, were lean at birth and had a high rate of catch-up growth in weight and length during the first 3 and 6 mo, respectively. After the initial phases of rapid catch-up in weight and length, mean values of SD scores for weight and height remained relatively unchanged up until 2 y of age, thereafter increasing gradually up to 7 y of age, leaving 4/46 (8%) and 4/46 (8%) below ,2 SD for weight and height, respectively. The pattern of changes in length/height and weight over time did not differ between those infants with abnormal BFC and those with normal BFC. The abnormal fetal aortic waveform was not related to rate of early catch-up growth or to height or weight at 7 y of age after adjustment for deviation in growth at birth. The magnitude of deficit in weight and length at birth was more predictive of subsequent growth. [source] Myocardial growth before and after birth: clinical implications,ACTA PAEDIATRICA, Issue 2 2000AM Rudolph Perinatal changes in myocardial growth have recently evoked considerable interest with regard to cardiac chamber development with congenital cardiac lesions and to myocardial development in preterm infants. It is suggested that cardiac chamber development is influenced by blood flow. Experimental pulmonary stenosis in fetal lambs may induce either greatly reduced or markedly increased right ventricular volume. Ventricular enlargement appears to be associated with a large ventricular volume load resulting from tricuspid valve regurgitation. A small competent tricuspid valve is associated with reduced flow through the ventricle due to outflow obstruction and a small right ventricle. Postnatal growth of the ventricles in congenital heart disease is discussed. Increase in myocardial mass prenatally is achieved by hyperplasia, both during normal development and when myocardial mass is increased by right ventricular outflow obstruction. Postnatally, increases in myocardial mass with normal growth, as well as with ventricular outflow obstruction, are largely due to hypertrophy of myocytes. Myocardial capillary numbers do not increase in proportion with myocyte numbers in ventricular myocardium in association with outflow obstruction. The postnatal effects of these changes in congenital heart lesions are considered. Studies in fetal lambs suggest that the late gestational increase in blood cortisol concentrations is responsible for the change in the pattern of myocardial growth after birth. The concern is raised that prenatal exposure of the premature infant to glucocorticoids, administered to the mother to attempt to prevent hyaline membrane disease in the infant, may inhibit myocyte proliferation and result in a heart with fewer than normal myocytes. This would necessitate that each myocyte would have to hypertrophy abnormally to achieve a normal cardiac mass postnatally. [source] Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae)ACTA ZOOLOGICA, Issue 2 2008Gabe S. Bever Abstract Bever, G.S. 2007. Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae). ,Acta Zoologica (Stockholm) 88: 000,000 Postnatal growth is one of the many aspects of developmental morphology that remains distinctly understudied in reptiles. Variation and ontogenetic scaling within the skull of the extant emydid turtle, Pseudemys texana is described based on 25 continuous characters. Results indicate that skull shape in this species changes little during postnatal growth relative to the only cryptodire taxa for which comparable datasets are available (Apalone ferox and Sternotherus odoratus). This relative lack of change results in the paedomorphic retention of a largely juvenile appearance in the adult form of P. texana. The skulls of males and females, despite the presence of distinct sexual dimorphism in size, grow with similar scaling patterns, and the few observed differences appear to reflect alteration of the male growth trajectory. Comparisons with A. ferox and S. odoratus reveal a number of similarities and differences that are here interpreted within a phylogenetic context. These preliminary hypotheses constitute predictive statements that phylogenetically bracket the majority of extant cryptodire species and provide baseline comparative data that are necessary for the future recognition of apomorphic transformations. Plasticity of ontogenetic scaling as a response to the homeostatic needs and behaviour of individuals commonly is evoked as a limitation of ontogenetic scaling as a means to inform phylogenetic studies. These evocations are largely unfounded considering that variability itself can evolve and thus be phylogenetically informative. [source] Postnatal growth and reproductive biology of Rhinolophus hipposideros (Chiroptera: Rhinolophidae)JOURNAL OF ZOOLOGY, Issue 3 2004Guido Reiter Abstract The timing of birth and postnatal growth in lesser horseshoe bats Rhinolophus hipposideros were studied during 2000 and 2001 at three maternity roosts located in the provinces of Carinthia and Salzburg, Austria. Postnatal growth curves for length of forearm and body mass were determined separately for the different colonies and years. Cooler weather during June 2001 coincided with a median birth date that was 8 days later than in 2000, whilst the difference between colonies was 4 and 5 days, respectively, for the pooled data of both years. Cool temperatures in June also coincided with a longer duration of the parturition period. Postnatal growth rates were higher than in most other bat species but differences between years and colonies were considerable. These differences may be attributed to the ambient roost temperatures, whereby the young of two cooler roosts showed significantly reduced growth rate during 8 days of cool weather in 2000. Moreover, later born and therefore smaller pups were more strongly affected by low temperatures than earlier born and larger ones. The mean length of forearm of young lesser horseshoe bats at the beginning of September equalled that of adult bats, whilst their body mass was still lower. Non-volant juveniles did not cluster following the nightly emergence of adult females, and a preferred location within the roosts could not be identified. High and very low roost temperatures, however, did have an influence on the location of non-volant young in the colonies. [source] Abnormal fetal aortic velocity waveform and postnatal growthACTA PAEDIATRICA, Issue 11 2000D Ley Postnatal growth from birth up to 7 y of age was evaluated in 151 children with varying degrees of intrauterine growth retardation who were previously examined in their intrauterine life with Doppler velocimetry of the thoracic descending aorta. The children with abnormal fetal aortic blood flow class (BFC), of which 39/46 (85%) had a birthweight 2 SD below the mean of the population, were lean at birth and had a high rate of catch-up growth in weight and length during the first 3 and 6 mo, respectively. After the initial phases of rapid catch-up in weight and length, mean values of SD scores for weight and height remained relatively unchanged up until 2 y of age, thereafter increasing gradually up to 7 y of age, leaving 4/46 (8%) and 4/46 (8%) below ,2 SD for weight and height, respectively. The pattern of changes in length/height and weight over time did not differ between those infants with abnormal BFC and those with normal BFC. The abnormal fetal aortic waveform was not related to rate of early catch-up growth or to height or weight at 7 y of age after adjustment for deviation in growth at birth. The magnitude of deficit in weight and length at birth was more predictive of subsequent growth. [source] Foetal size to final heightACTA PAEDIATRICA, Issue 6 2000J Karlberg It is well known that some adult diseases, such as cardiovascular diseases, may be programmed during foetal life. It is not clear, however, whether final height may be predicted from foetal growth. A longitudinal cohort of full-term healthy Swedish babies (n = 3650) was followed up from birth to maturity in a population-based growth study. Length or height and its changes were analysed from birth to 18 y of age; 2807 children, with data available on birth length, final height and parental height, were included in this analysis. The result clearly shows that length at birth relates to final height. In terms of standard deviation scores (SDS), the mean difference in length at birth from the mean was greatly decreased in final height, but retained the same order as was seen at birth. In terms of centimeter difference from the reference mean values, the difference in length at birth remained roughly stable into final height. For instance, babies 5 cm above or below the mean birth length will end up approximately 5 cm above or below the mean in final height. Parental height,a surrogate value of the genetic final height potential of an individual,is shown to influence postnatal growth in height strongly. However, the difference from the mean in length at birth remained into adulthood within the same midparental height group. Conclusion: This study reveals that trends in foetal linear growth continue into maturity. Foetal growth is a significant predictor of postnatal growth. Final height is dependent on both the magnitude of foetal growth and the genetic potential in stature, and appears to some extent to be programmed from foetal growth. [source] Prenatal growth, postnatal growth and trait anxiety in late adulthood , the Helsinki Birth Cohort StudyACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2010J. Lahti Lahti J, Räikkönen K, Pesonen A-K, Heinonen K, Kajantie E, Forsén T, Osmond C, Barker DJP, Eriksson JG. Prenatal growth, postnatal growth and trait anxiety in late adulthood , the Helsinki Birth Cohort Study. Objective:, Trait anxiety may predispose to anxiety disorders and cardiovascular events. We tested whether prenatal growth or postnatal growth from birth to 11 years of age and in adulthood predict trait anxiety in late adulthood. Method:, Women (n = 951) and men (n = 753) reported trait anxiety using the Spielberger Trait Anxiety Scale at an average age of 63.4 years and growth was estimated from records. Results:, Higher trait anxiety was predicted by smaller body size at birth, in infancy and in adulthood. Moreover, faster growth particularly from seven to 11 years of age and slower growth between 11 and 63 years predicted higher trait anxiety. Conclusion:, We found a pattern of pre- and postnatal growth that predisposed to higher trait anxiety in late adulthood. This pattern resembles that found to increase the risk of cardiovascular events and, thus, points to a shared common origin in a suboptimal prenatal and childhood developmental milieu. [source] Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae)ACTA ZOOLOGICA, Issue 2 2008Gabe S. Bever Abstract Bever, G.S. 2007. Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae). ,Acta Zoologica (Stockholm) 88: 000,000 Postnatal growth is one of the many aspects of developmental morphology that remains distinctly understudied in reptiles. Variation and ontogenetic scaling within the skull of the extant emydid turtle, Pseudemys texana is described based on 25 continuous characters. Results indicate that skull shape in this species changes little during postnatal growth relative to the only cryptodire taxa for which comparable datasets are available (Apalone ferox and Sternotherus odoratus). This relative lack of change results in the paedomorphic retention of a largely juvenile appearance in the adult form of P. texana. The skulls of males and females, despite the presence of distinct sexual dimorphism in size, grow with similar scaling patterns, and the few observed differences appear to reflect alteration of the male growth trajectory. Comparisons with A. ferox and S. odoratus reveal a number of similarities and differences that are here interpreted within a phylogenetic context. These preliminary hypotheses constitute predictive statements that phylogenetically bracket the majority of extant cryptodire species and provide baseline comparative data that are necessary for the future recognition of apomorphic transformations. Plasticity of ontogenetic scaling as a response to the homeostatic needs and behaviour of individuals commonly is evoked as a limitation of ontogenetic scaling as a means to inform phylogenetic studies. These evocations are largely unfounded considering that variability itself can evolve and thus be phylogenetically informative. [source] Insulin-like growth factors and pancreas beta cellsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 4 2004T. W. Van Haeften Abstract Insulin-like growth factors (IGFs) have been implicated in normal growth, and especially foetal pancreas beta-cell development. As low birth weight has been implicated in the development of obesity and type 2 diabetes, much research has evolved into the importance of IGF and their signalling pathways for pancreas beta-cell development, and for type 2 diabetes. Insulin-like growth factor-I signalling has a lot in common with insulin signalling, and is involved in diverse cellular effects such as antiapoptosis, protein synthesis, cell growth and mitogenesis. Insulin-like growth factor-II can be bound by the insulin receptor A subtype and the IGF-1 receptor, which may explain its antiapoptotic effect. Various knock-out model studies indicate that absence of IGF-I or the IGF-1 receptor is critical for foetal and postnatal growth. Similarly, knock-out models of post-receptor molecules (such as IRS-2) point to the physiological role of IGFs for pancreas beta-cell development. A beta-cell-specific IGF-1 receptor knock out model indicates the importance of IGF-I for beta-cell function. The Goto-Kakizaki (GK) rat, a model for diabetes, has insufficient beta-cell development, which may be related to its defective IGF-II synthesis. As normal pancreas beta cells adapt to the prevailing insulin resistance with increasing beta-cell function, it is possible that insulin resistance interacts with IGF signalling in pancreas beta cells. [source] Consequences of maternal yolk testosterone for offspring development and survival: experimental test in a lizardFUNCTIONAL ECOLOGY, Issue 3 2007T. ULLER Summary 1Hormone-mediated maternal effects and developmental plasticity are important sources of phenotypic variation, with potential consequences for trait evolution. Yet our understanding of the importance of maternal hormones for offspring fitness in natural populations is very limited, particularly in non-avian species. 2We experimentally elevated yolk testosterone by injection of a physiological dose into eggs of the lizard Ctenophorus fordi Storr, to investigate its roles in offspring development, growth and survival. 3Yolk testosterone did not influence incubation period, basic hatchling morphology or survival under natural conditions. However, there was evidence for increased growth in hatchlings from testosterone-treated eggs, suggesting that maternal hormones have potential fitness consequences in natural populations. 4The positive effect of prenatal testosterone exposure on postnatal growth could represent a taxonomically widespread developmental mechanism that has evolved into an adaptive maternal effect in some taxa, but remains deleterious or selectively neutral in others. 5A broader taxonomic perspective should increase our understanding of the role of physiological constraints in the evolution of endocrine maternal effects. [source] Bile duct proliferation in liver-specific Jag1 conditional knockout mice: Effects of gene dosage,HEPATOLOGY, Issue 2 2007Kathleen M. Loomes The Notch signaling pathway is involved in determination of cell fate and control of cell proliferation in multiple organ systems. Jag1 encodes a ligand in the Notch pathway and has been identified as the disease-causing gene for the developmental disorder Alagille syndrome. Evidence from the study of human disease and mouse models has implicated Jag1 as having an important role in the development of bile ducts. We have derived a conditional knockout allele (Jag1loxP) to study the role of Jag1 and Notch signaling in liver and bile duct development. We crossed Jag1loxP mice with a transgenic line carrying Cre recombinase under the control of the albumin promoter and ,-fetoprotein enhancer to ablate Jag1 in hepatoblasts. The liver-specific Jag1 conditional knockout mice showed normal bile duct development. To further decrease Notch pathway function, we crossed the Jag1 conditional knockout mice with mice carrying the hypomorphic Notch2 allele, and bile duct anatomy remained normal. When Jag1 conditional mice were crossed with mice carrying the Jag1 null allele, the adult progeny exhibited striking bile duct proliferation. Conclusion: These results indicate that Notch signaling in the liver is sensitive to Jag1 gene dosage and suggest a role for the Notch pathway in postnatal growth and morphogenesis of bile ducts. (HEPATOLOGY 2007.) [source] Pelvic growth: Ontogeny of size and shape sexual dimorphism in rat pelvesJOURNAL OF MORPHOLOGY, Issue 1 2007S. Berdnikovs Abstract The mammalian pelvis is sexually dimorphic with respect to both size and shape. Yet little is known about the differences in postnatal growth and bone remodeling that generate adult sexual dimorphism in pelvic bones. We used Sprague-Dawley laboratory rats (Rattus norvegicus), a species that exhibits gross pelvic size and shape dimorphism, as a model to quantify pelvic morphology throughout ontogeny. We employed landmark-based geometric morphometrics methodology on digitized landmarks from radiographs to test for sexual dimorphism in size and shape, and to examine differences in the rates, magnitudes, and directional patterns of shape change during growth. On the basis of statistical significance testing, the sexes became different with respect to pelvic shape by 36 days of age, earlier than the onset of size dimorphism (45 days), although visible shape differences were observed as early as at 22 days. Males achieved larger pelvic sizes by growing faster throughout ontogeny. However, the rates of shape change in the pelvis were greater in females for nearly all time intervals scrutinized. We found that trajectories of shape change were parallel in the two sexes until age of 45 days, suggesting that both sexes underwent similar bone remodeling until puberty. After 45 days, but before reproductive maturity, shape change trajectories diverged because of specific changes in the female pelvic shape, possibly due to the influence of estrogens. Pattern of male pelvic bone remodeling remained the same throughout ontogeny, suggesting that androgen effects on male pelvic morphology were constant and did not contribute to specific shape changes at puberty. These results could be used to direct additional research on the mechanisms that generate skeletal dimorphisms at different levels of biological organization. J. Morphol., 2006. © 2006 Wiley-Liss, Inc. [source] A randomized trial of enteral feeding volumes in infants born before 30 weeks' gestationJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 6 2000C A Kuschel Objective: To compare the effect of two volumes of enteral feeds on postnatal growth in infants born before 30 weeks gestation. Methodology: Fifty-four infants, less than 30 weeks gestational age, who reached full enteral feeds were randomized to remain on 150 mL/kg per day (150 group) or increase to 200 mL/kg per day (200 group). The primary outcome measure was growth at 35 weeks corrected gestational age (CGA). Results: There were no statistically significant differences in demographic or clinical parameters between the study groups at commencement of the study, although there was a trend for infants in the 150 group to be lighter (895 g vs 1020 g, P = 0.27). Milk intakes were increased in 43% of the infants in the 150 group, whereas 54% of the infants in the 200 group required reduced intakes. Infants in the 200 group had greater daily weight gains (16.7 g/kg per day vs 15.2 g/kg per day, P = 0.047) and at 35 weeks CGA were heavier (2020 g vs 1885 g, P = 0.014) and had a greater arm fat area (282 mm2vs 218 mm2, P = 0.009). There was no difference in length or head circumference at 35 weeks CGA, and no difference in any growth parameter at 1 year of age. Morbidity was not different between the groups. Conclusions: The individual milk volume requirements for adequate weight gain without significant adverse effects vary between 150 and 200 mL/kg per day in extremely premature infants. For many infants in both groups, the assigned target volume was not appropriate. Increased milk intakes (and therefore higher caloric and mineral intakes) are associated with increased daily weight gains and a greater weight at 35 weeks CGA. The weight gain may be due to an increase in fat deposition. [source] Dietary Zinc Supplementation Throughout Pregnancy Protects Against Fetal Dysmorphology and Improves Postnatal Survival After Prenatal Ethanol Exposure in MiceALCOHOLISM, Issue 4 2009Brooke L. Summers Background:, We have previously demonstrated that ethanol teratogenicity is associated with metallothionein-induced fetal zinc (Zn) deficiency, and that maternal subcutaneous Zn treatment given with ethanol in early pregnancy prevents fetal abnormalities and spatial memory impairments in mice. Here we investigated whether dietary Zn supplementation throughout pregnancy can also prevent ethanol-related dysmorphology. Methods:, Pregnant mice were injected with saline or 25% ethanol (0.015 ml/g intraperitoneally at 0 and 4 hours) on gestational day (GD) 8 and fed either a control (35 mg Zn/kg) or a Zn-supplemented diet (200 mg Zn/kg) from GD 0 to 18. Fetuses from the saline, saline + Zn, ethanol and ethanol + Zn groups were assessed for external birth abnormalities on GD 18. In a separate cohort of mice, postnatal growth and survival of offspring from these treatment groups were examined from birth until postnatal day 60. Results:, Fetuses from dams treated with ethanol alone in early pregnancy had a significantly greater incidence of physical abnormalities (26%) compared to those from the saline (10%), saline + Zn (9%), or ethanol + Zn (12%) groups. The incidence of abnormalities in ethanol + Zn-supplemented fetuses was not different from saline-treated fetuses. While ethanol exposure did not affect the number of fetal resorptions or pre- or postnatal weight, there were more stillbirths with ethanol alone, and cumulative postnatal mortality was significantly higher in offspring exposed to ethanol alone (35% deaths) compared to all other treatment groups (13.5 to 20.5% deaths). Mice supplemented with Zn throughout pregnancy had higher plasma Zn concentrations than those in un-supplemented groups. Conclusions:, These findings demonstrate that dietary Zn supplementation throughout pregnancy ameliorates dysmorphology and postnatal mortality caused by ethanol exposure in early pregnancy. [source] Birth size and postnatal growth in cave- and bridge-roosting Brazilian free-tailed batsJOURNAL OF ZOOLOGY, Issue 1 2010L. C. Allen Abstract As the human population continues to expand, increased encroachment on natural landscapes and wildlife habitats is expected. Organisms able to acclimate to human-altered environments should have a selective advantage over those unable to do so. Over the past two decades, bats have increasingly begun to roost and raise offspring in spaces beneath pre-cast concrete bridges. Few studies have examined the health or fitness of individuals living in these anthropogenic sites. In the present study, we examined birth size and postnatal growth, as surrogates of reproductive success, in Brazilian free-tailed bat pups born at a natural and a human-made roost. Based on putative stress-related conditions (noise from vehicular traffic, chemical pollutants and a modified social environment) present at bridges, we predicted that bats at these sites would have reduced reproductive success. Contrary to our prediction, pups born at a bridge site were on average heavier and larger at birth and grew faster than those born at a cave site. Also, both birth size and growth rates of pups differ between years. We attribute observed differences to a combination of roost-related conditions (i.e. roost temperature and proximity to foraging areas), climate and maternal effects with larger mothers raising larger pups. Thus, some bridge roosts, at least in the short term, are suitable, and in some cases may provide better conditions, for raising young bat pups than cave roosts. [source] Partitioning of metabolizable energy intake in sucking altricial and precocial rodent pupsJOURNAL OF ZOOLOGY, Issue 4 2006M. Kam Abstract We partitioned the metabolizable energy intake (MEI) into energy for maintenance (MEm) and for growth (MEg) in sucking precocial and altricial rodent pups. Each of the two components includes energy loss due to the heat increment of feeding. MEm of precocial pups expressed as average daily energy costs or as a proportion of MEI was greater than in altricial pups of similar size and, therefore, less energy was available for growth. Consequently, the overall energy cost (via total MEI) per unit postnatal growth of precocial pups was greater than for altricial pups of similar size. We used the proportion of calculated MEm to that predicted by body mass as an index of precociality in rodent pups. The proportion of MEg to MEI in precocial pups was lower than in altricial pups and was inversely related to the index of precociality. [source] A comparative study of growth, skeletal development and eggshell composition in some species of birdsJOURNAL OF ZOOLOGY, Issue 4 2004Jonas Blom Abstract Some studies of birds suggest that the development of the skeleton may invoke a constraint on the rate of postnatal growth. Other studies have shown that the eggshell is the major source of calcium for skeletal development of the embryo. To test whether avian growth rate is indeed associated with different patterns of skeletal development, we compared the degree of skeletal ossification of the long bones of the wing and the leg of one slowly growing precocial species (quail Coturnix japonica) with that of two rapidly growing altricial species (starling Sturnus vulgaris and fieldfare Turdus pilaris). The degree of skeletal ossification of the long bones of the wings and legs of lines of quails that had undergone long-term selection for high- and low-growth rate, respectively, also was compared with a non-selected control line. Next, the fine structure of the inner eggshell surface (mammillary layer) of both pre- and post-incubated eggs, i.e. before and after embryonic development/calcium removal was compared. The data show that the skeleton of the more rapidly growing species and lines was less ossified than that of the more slowly growing ones. This difference appeared to be associated with different rates of calcium removal from the eggshell. Removal was more extensive in eggs of quail than in eggs of starling and fieldfare, i.e. more extensive in shells with a high number of mammillary tips per unit of surface area than in shells with a lower number. It is therefore concluded that growth rate is of fundamental importance for the pattern of skeletal development. Moreover, the mammillary density varies between different bird species, it is suggested, in order to support the different rates of calcium removal by developing embryos. [source] Postnatal growth and reproductive biology of Rhinolophus hipposideros (Chiroptera: Rhinolophidae)JOURNAL OF ZOOLOGY, Issue 3 2004Guido Reiter Abstract The timing of birth and postnatal growth in lesser horseshoe bats Rhinolophus hipposideros were studied during 2000 and 2001 at three maternity roosts located in the provinces of Carinthia and Salzburg, Austria. Postnatal growth curves for length of forearm and body mass were determined separately for the different colonies and years. Cooler weather during June 2001 coincided with a median birth date that was 8 days later than in 2000, whilst the difference between colonies was 4 and 5 days, respectively, for the pooled data of both years. Cool temperatures in June also coincided with a longer duration of the parturition period. Postnatal growth rates were higher than in most other bat species but differences between years and colonies were considerable. These differences may be attributed to the ambient roost temperatures, whereby the young of two cooler roosts showed significantly reduced growth rate during 8 days of cool weather in 2000. Moreover, later born and therefore smaller pups were more strongly affected by low temperatures than earlier born and larger ones. The mean length of forearm of young lesser horseshoe bats at the beginning of September equalled that of adult bats, whilst their body mass was still lower. Non-volant juveniles did not cluster following the nightly emergence of adult females, and a preferred location within the roosts could not be identified. High and very low roost temperatures, however, did have an influence on the location of non-volant young in the colonies. [source] Linear growth in early life is associated with suicidal ideation in 18-year-old FilipinosPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 5 2009Yin Bun Cheung Summary Studies in Western societies have shown some evidence that growth in early life may be associated with suicide and suicidal ideation in later life. The pattern of growth retardation in developing countries is different from that in Western societies. This study examines the association between size at birth, postnatal growth from birth to age 24 months and suicidal ideation in 18-year-old Filipinos. The 1941 participants born in 1983 and 1984 in the Philippines were assessed for growth status bimonthly from birth to 24 months of age and were administered an interview in 2002, which included items on suicidal ideation. The pattern of growth stunting in this cohort was similar to that in many other developing countries: a minor level of shortness in crown-heel length at birth followed by sharp decline in length-for-age in the first 24 months of life. The prevalence of suicidal ideation at age 18 was 2.9%; 95% confidence interval [CI] 2.2, 3.8%. Length Z-score at 24 months (odds ratios [OR] = 0.67; 95% CI [0.52, 0.86]; P = 0.002) and gain in length Z-score from birth to age 24 months (OR = 0.74; 95% CI [0.56, 0.98]; P = 0.037) were inversely associated with the odds of suicidal ideation. Adjustment for covariates made little difference. Length at birth Z-score was associated with suicidal ideation only after adjustment for postnatal length gain (OR = 0.61; 95% CI [0.46, 0.80]; P < 0.001). The associations between linear growth in early life and suicidal ideation appeared to be partly mediated by educational attainment. In conclusion, postnatal growth stunting is an important predictor of suicidal ideation in later life. It also affects the association between birth length and suicidal ideation. [source] Worldwide childhood type 1 diabetes incidence , what can we learn from epidemiology?PEDIATRIC DIABETES, Issue 2007G Soltesz Abstract:, Type 1 diabetes is the most common form of diabetes in most part of the world, although reliable data are still unavailable in several countries. Wide variations exist between the incidence rates of different populations, incidence is lowest in China and Venezuela (0.1 per 100 000 per year) and highest in Finland and Sardinia (37 per 100 000 per year). In most populations girls and boys are equally affected. In general, the incidence increases with age, the incidence peak is at puberty. After the pubertal years, the incidence rate significantly drops in young women, but remains relatively high in young adult males up to the age 29,35 years. Prospective national and large international registries (DIAMOND and EURODIAB) demonstrated an increasing trend in incidence in most regions of the world over the last few decades and increases seem to be the highest in the youngest age group. Analytical epidemiological studies have identified environmental risk factors operating early in life which might have contributed to the increasing trend in incidence. These include enteroviral infections in pregnant women, older maternal age (39,42 years), preeclampsia, cesarean section delivery, increased birthweight, early introduction of cow's milk proteins and an increased rate of postnatal growth (weight and height). Optimal vitamin D supplementation during early life has been shown to be protective. Some of these environmental risk factors such as viruses may initiate autoimmunity toward the beta cell, other exposures may put on overload on the already affected beta cell and thus accelerate the disease process. [source] Comparative and evolutionary dimensions of the energetics of human pregnancy and lactationAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 5 2002D.L. Dufour The purpose of this article is to compare the energetics of reproduction for human and other primates in order to evaluate the extent to which human reproductive energetics are distinct from other primates and other large-bodied placental mammals. The article also evaluates the energetics of human and primate gestation and lactation using data from a variety of different populations living under different environmental circumstances. Energetics refers to energy intake and expenditure, and changes in body fat stores. Human and nonhuman primates have longer periods of gestation and lactation and slower prenatal and postnatal growth than other mammals of similar size. This reduces daily maternal energy costs. The development of sizable fat stores is not unique to humans, but fat stores are typically greater in human females and may play a greater role in reproduction. The strategies used to meet the energy costs of pregnancy vary among populations of humans and nonhuman primates and among humans interindividual variability is high. In pregnancy, some increase energy intake but others apparently do not. Increases in metabolic efficiency are evident in some human populations, whereas decreases in physical activity occur, but are not seen in all human or primate populations. Lactation is more energetically costly on a daily basis among humans and nonhuman primates, but has not been as well studied. It appears that both nonhuman and human primates tend to increase energy intake to meet in part the cost of lactation. They also use other strategies such as relying on body tissue stores, reductions in physical activity, and/or increases in metabolic efficiency to meet the remainder of the cost. It is also clear that human females in different populations and different women in the same population use a different combination of strategies to meet the cost of lactation. Am. J. Hum. Biol. 14:584,602, 2002. © 2002 Wiley-Liss, Inc. [source] A comparison of the ontogeny of shape variation in the anthropoid scapula: Functional and phylogenetic signalAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2008Nathan M. Young Abstract This article compares ontogenetic shape variation in the scapula of 17 anthropoid species using three-dimensional landmark-based geometric morphometrics. These data are used to investigate functional and phylogenetic signal in the major components of scapular variation and to evaluate the degree to which postnatal growth contributes to interspecific differences in shape. Results indicate that the shape of the infant and adult scapula is primarily associated with positional behavior (e.g., orthograde suspensory nonquadrupeds versus pronograde quadrupeds), but within this functional structure there is phylogenetic signal, particularly at infant stages. Growth most closely correlates with infant/adult shape and locomotor function. These results suggest that the shape of the infant scapula drives the pattern of postnatal scapular growth and adult morphology. As such, variation in postnatal growth is not the primary source of interspecific variation in adult shape. Instead, interspecific differences in scapular morphology are hypothesized to be the result of selection for variation in embryonic developmental processes that affect shape. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc. [source] Relationship between formation of the femoral bicondylar angle and trochlear shape: Independence of diaphyseal and epiphyseal growthAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2006C. Tardieu Abstract During hominin evolution, an increase in the femoral bicondylar angle was the initial change that led to selection for protuberance of the lateral trochlear lip and the elliptical profile of the lateral condyle. No correlation is found during ontogeny between the degree of femoral obliquity and of the prominence of the lateral trochlear lip. Might there be a relationship with the elliptical profile of the lateral condyle? On intact femoral diaphyses of juvenile humans and great apes, we compared the anteroposterior length of the lateral and medial sides of the distal metaphysis. The two diaphyseal pillars remain equal during postnatal growth in great apes, while the growth of the lateral pillar far exceeds that of the medial pillar in humans. Increase in bicondylar angle is correlated with disproportionate anteroposterior lengthening of the lateral pillar. The increased anteroposterior length of the lateral side of the metaphysis would contribute to increasing the radius of the curvature of the lateral condyle, but not to the projection of the lateral trochlear lip. The similar neonatal and adult femoro-patellar joint shape in humans prompted an assessment of the similarity during growth of the entire neonatal and adult epiphyses. We showed that the entire epiphysis undergoes drastic changes in proportions during postnatal growth. Finally, we emphasize the need to distinguish the cartilaginous phenotype and the ossified phenotype of the distal femoral epiphysis (and of any epiphysis) during postnatal growth. This crucial distinction applies to most postcranial bones, for they almost all develop following the process of endochondral ossification. Am J Phys Anthropol, 2006. © 2006 Wiley-Liss, Inc. [source] Uteroplacental insufficiency causes a nephron deficit, modest renal insufficiency but no hypertension with ageing in female ratsTHE JOURNAL OF PHYSIOLOGY, Issue 11 2009Karen M. Moritz In rats, uteroplacental insufficiency induced by uterine vessel ligation restricts fetal growth and impairs mammary development compromising postnatal growth. In male offspring, this results in a nephron deficit and hypertension which can be reversed by improving lactation and postnatal growth. Here, growth, blood pressure and nephron endowment in female offspring from mothers which underwent bilateral uterine vessel ligation (Restricted) on day 18 of pregnancy were examined. Sham surgery (Control) and a reduced litter group (Reduced at birth to 5, equivalent to Restricted group) were used as controls. Offspring (Control, Reduced, Restricted) were cross-fostered on postnatal day 1 onto a Control (normal lactation) or Restricted (impaired lactation) mother. Restricted-on-Restricted offspring were born small but were of similar weight to Control-on-Control by postnatal day 35. Blood pressure was not different between groups at 8, 12 or 20 weeks of age. Glomerular number was reduced in Restricted-on-Restricted offspring at 6 months without glomerular hypertrophy. Cross-fostering a Restricted pup onto a Control dam resulted in a glomerular number intermediate between Control-on-Control and Restricted-on-Restricted. Blood pressure, along with renal function, morphology and mRNA expression, was examined in Control-on-Control and Restricted-on-Restricted females at 18 months. Restricted-on-Restricted offspring did not become hypertensive but developed glomerular hypertrophy by 18 months. They had elevated plasma creatinine and alterations in renal mRNA expression of transforming growth factor-,1, collagen IV (,1) and matrix matelloproteinase-9. This suggests that perinatally growth restricted female offspring may be susceptible to onset of renal injury and renal insufficiency with ageing in the absence of concomitant hypertension. [source] The H19 locus: Role of an imprinted non-coding RNA in growth and developmentBIOESSAYS, Issue 6 2010Anne Gabory Abstract The H19 gene produces a non-coding RNA, which is abundantly expressed during embryonic development and down-regulated after birth. Although this gene was discovered over 20 years ago, its function has remained unclear. Only recently a role was identified for the non-coding RNA and/or its microRNA partner, first as a tumour suppressor gene in mice, then as a trans-regulator of a group of co-expressed genes belonging to the imprinted gene network that is likely to control foetal and early postnatal growth in mice. The mechanisms underlying this transcriptional or post-transcriptional regulation remain to be discovered, perhaps by identifying the protein partners of the full-length H19 RNA or the targets of the microRNA. This first in vivo evidence of a functional role for the H19 locus provides new insights into how genomic imprinting helps to control embryonic growth. [source] Update on risk factors and future perspectives for preterm infantsACTA OPHTHALMOLOGICA, Issue 2009A HELLSTRöM Purpose To give an update on risk factors for retinopathy of prematurity with special focus on postnatal growth and growth factors Methods The relationship between birth weight, serum levels of IGF-I as well as postnatal longitudinal growth and ROP will be presented. Preventive measures will be discussed. Results Birth weight data on 451 infants demonstrated initially a significant difference in BW between different ROP stages but when taking gestational age and sex into account the significance was eliminated. Recently, a new diagnostic tool based on weekly neonatal measurements of body weight and serum insulin-like growth factor 1 (IGF-I) levels, was shown to be predictive for ROP development. The algorithm "Weight IGF-I Neonatal ROP" (WINROPÔ) predicted early (mean 10 weeks) all infants who later developed proliferative ROP requiring treatment. The WINROP algorithm was then taken one step further using only serial weight measurements (n=700), excluding blood sampling for measuring IGF-I. With this approach WINROP predicted all infants who later developed proliferative ROP requiring treatment (100% sensitivity) and correctly identified 75% of those who did not develop proliferative ROP, and thus would not need any ophthalmologic screening. We have also shown a close relationship between postnatal growth, severe ROP and poor brain development. Conclusion For decades, neonatal intensive care has focused on survival of the most immature babies. Time has come to find methods to ameliorate the nutrition for the children born very preterm. It is known that IGF-I is essential for growth and development of the immature vasculature of the eye. Intervention with substitution of IGF-I to the very preterm babies to raise IGF-I up to normal intrauterine levels might be beneficial. Commercial interest [source] Early postnatal growth variables are related to morphologic and functional ophthalmologic outcome in children born pretermACTA PAEDIATRICA, Issue 5 2010M Hök-Wikstrand Abstract Aim:, To evaluate the association between gestational age (GA), early and late postnatal growth variables and ophthalmologic outcome in ex-preterm children. Methods:, Children (GA < 32 weeks, n = 66), previously examined regarding insulin-like growth factor 1 (IGF-1) serum concentrations in relation to ROP, underwent ophthalmologic examination at median 5.6 years. Weight, height, and head circumference (HC) were measured and expressed as SDS. Growth variables were analysed in relation to ophthalmologic outcome. Results:, At follow-up 74% had some ophthalmologic abnormality and 17% had visual impairment. Poor visual acuity was correlated with low GA (rs = 0.29, p = 0.019), low weight at 32 weeks (rs = 0.30, p = 0.013), and low weight (rs = 0.37, p = 0.0025), height (rs = 0.41, p = 0.0007) and HC (rs = 0.55, p < 0.0001) at follow-up. Hyperopic children (25%) had low neonatal IGF-1 (p = 0.0096) and HC at follow-up (p = 0.022). Poor visual perception was correlated with low early weight (rs = 0.38, p = 0.0036) and HC at follow-up (rs = 0.39, p = 0.0024). Head circumference at follow-up was correlated with GA (rs = 0.40, p = 0.0012), neonatal IGF-1 (rs = 0.37, p = 0.0031), and early weight (rs = 0.27, p = 0.035). Conclusions:, In very preterm children, early and later postnatal growth is closely related to visual acuity and perception at follow-up. In addition, IGF-1 concentrations and early growth are correlated with head circumference and refraction at follow-up. [source] IGF-I, leptin and active ghrelin levels in very low birth weight infants during the first 8 weeks of lifeACTA PAEDIATRICA, Issue 1 2010N Ohkawa Abstract Aim:, We investigated the relationship between plasma insulin-like growth factor I (IGF-I), leptin, active ghrelin levels, and postnatal growth in very low birth weight (VLBW) infants. Method:, Plasma IGF-I, leptin, and active ghrelin levels were measured at birth and at 2, 4, 6 and 8 weeks after birth in 61 VLBW infants, including 31 appropriate-for-gestational-age (AGA) and 30 small-for-gestational-age (SGA) infants. Results:, Insulin-like growth factor I levels were the lowest at birth, but increased gradually over the first 8 weeks of life. IGF-I was positively correlated with body weight, body length and body mass index at all time points. Leptin levels did not change over the study period. Ghrelin levels were significantly lower at birth; however, there were no significant differences between the levels after 2 weeks of age. Leptin and ghrelin levels were not correlated with anthropometrical measures. IGF-I levels at birth were significantly lower in SGA than in AGA infants, but the leptin and ghrelin levels were not significantly different between the two groups. Conclusion:, Insulin-like growth factor I is related to length and weight gain in the prenatal and the early postnatal periods in VLBW infants, but this does not appear to be the case for leptin and ghrelin. [source] | |||||||||||||||||||||||||