Effect of maternal exercise on fetal and placental glycogen storage in the mature rat.

The purpose was to determine the effects of exercise on fetal and placental glycogen storage patterns at 20 days gestation (term 21 days) in mature (approximately 12 months of age) Sprague-Dawley rats. The exercise protocol consisted of treadmill running at 30 m min-1, on a 10 incline, for 60 min, 5 days per week, for 4 weeks prior to conception, which continued until day 19 of pregnancy. Exercise produced a significant reduction in fetal body weight, placental weight, and fetal organ weights (heart, kidney, brain, and liver) compared to sedentary control animals (p <.05). However, when fetal body size was taken into account, these differences disappeared, except for the fetal brain:body weight ratio, which was larger in the exercised animals compared to controls (p <.05). Fetal liver glycogen concentrations were significantly lower in exercised animals compared to nonrunning control animals (p <.05). These results demonstrate that exercise of mature rats may compromise fetal development and hepatic glycogen storage in the fetus.     

The quantitative relationship between nutritional effects on preweaning growth and behavioral development in mice

Our objective was to establish whether nutritional effects on the behavioral development of preweaning mouse pups were linearly related to effects on body and brain growth or whether there was a threshold effect, with behavior being affected only by nutritional extremes. We also used a standardized scale of development to compare the relative magnitude of such effects on morphological and behavioral measures. The level of nutrient availability was manipulated continuously by rearing the pups in litter sizes ranging from 3 to 12. On Day 32 post-conception, measures were taken of body weight, brain weight, thickness of the cerebellar external granular layer (EGL), and behavioral development. The relationship between litter size and body weight, brain weight, and behavioral development was best described by a linear regression model; no threshold effect was apparent. By comparing measures on animals from different litter sizes at the same age (32 days) to standard developmental curves over a wide range of ages, we found that for every additional pup in a litter, body growth was retarded by the equivalent of 1.28 days, brain weight by 0.44 day, and behavioral development by 0.07 day. Although the variation in nutrient availability provided by this range of litter sizes does result in a linear relationship between growth and behavioral development, there is nevertheless considerable sparing of function.     

Fetal brain to liver weight ratio as a measure of intrauterine growth retardation: analysis of 182 stillborn autopsies.

The fetal brain/liver weight ratio of 182 stillborn fetuses was analyzed for its value as a measure of intrauterine growth retardation. The ratio was evaluated as a test for the detection of small-for-gestational age fetuses, compared with the ponderal index, and evaluated for correlation with maternal histories that were compatible with fetal growth retardation. Both brain/liver ratio and ponderal index were insensitive and relatively nonspecific indicators of low fetal body weight in this population. Brain/liver weight ratio was considerably more sensitive in those cases that were at least 20 weeks of gestational age, and specificity increased as the cut-off point was increased above 3. Those cases with maternal history or placental findings compatible with asymmetrical-type intrauterine growth retardation were statistically more likely to have elevated brain/liver weight ratios and depressed ponderal indices, but there was considerable overlap among cases with different disease types. Prosectors of fetal autopsies must make use of all the information available to them. The fetal brain/liver weight ratio and the ponderal index may be useful, but they are not satisfactory indicators of intrauterine growth retardation by themselves, and they also may be inadequate for the detection of growth retardation etiology.     

Postnatal brain growth and allometry in the rabbit Oryctolagus cuniculus

A new four-parameter version of Pütter's growth curve (Pütter, 1920) recently developed by Jolicoeur and Pirlot (1988) is applied to cross-sectional data on brain and body weight in 66 male rabbits (Oryctolagus cuniculus) ranging up to one year in postnatal age. Apart from the olfactory bulb, in which there appears to be no initial delay, the estimated initial delays range from 21.7 days (after fertilization) for the cerebellum to 29.9 days for the cerebrum, which suggests that the weight of most regions of the brain, as well as body weight, start increasing rapidly only toward the end of pregnancy (30 days on the average). These initial delays may be related to the fact that rabbits are born very small, naked, blind, and helpless. Expressed on log-log scales, bivariate allometric trajectories have very diverse shapes, including approximate straight lines, curves possessing a single upward or downward convexity, and even sigmoid or inverted sigmoid curves. It seem doubtful whether, if age were unknown, a reasonably simple mathematical function could possess enough flexibility to describe all of these kinds of relationships satisfactorily.     

Relation between brain and body growth in allied rats.

Cranial volumes were measured from museum specimens of wild-caught and laboratory-born Allied rats from eastern Australia. The relation of these volumes to body weight and body length, and also to age at death in the laboratory-reared sample, was determined. Growth of both brain and body was rapid during the first three postnatal months and slowed markedly over the next month, but appeared to continue at a very slow rate throughout life. In particular, the major surge in brain growth occurred in the first three postnatal weeks. Modified Gompertzian growth functions describe the pattern of growth quite well, though the nature of the data precluded highly sensitive fits. Three features were clear: 1) the rate of slowing of growth was about the same for all variables, 2) growth appeared to continue throughout the life of the animal, and 3) the trajectory of brain growth led that of body growth by about four days. The pattern of growth in Allied rats is similar to that of laboratory rats and probably to those in other murids.     

Immunostimulation and growth faltering in UK infants.

The purpose of the study was to determine whether chronic immunostimulation could explain growth faltering in disadvantaged children in the UK, as it does in developing countries such as The Gambia. In all, 216 infants, age 10-21 months, were recruited when blood samples were taken for the routine or clinical purposes of a longitudinal study tracking a larger cohort of children. Aliquots of blood were collected on Guthrie cards to determine blood concentrations of albumin (Alb), alpha(1)-antichymotrypsin (ACT), and immunoglobulin G (IgG). Haemoglobin concentrations were determined by routine hospital laboratory analysis. Heights and weights were measured and converted to z-scores; birth weights were used with recruitment weight to calculate a 'thrive index' for each child. Age-corrected plasma IgG concentration was negatively associated with both height- and weight-for-age z-scores (P = 0.042 and 0.038, respectively) but not with the thrive index or body mass index z-scores. Blood haemoglobin levels were positively related to height- and weight-for age z-scores, as well as to the thrive index (P = 0.026, 0.014, and 0.007, respectively). Although significant, these relationships could only account for a small part the observed growth variation. Although the relationships were weak, the results suggest that some of the observed variation in growth of these UK infants may be explained on the basis of persistent immunostimulation or poor iron status. In terms of markers of immunostimulation (Alb, ACT, ACT:Alb ratio, IgG), both absolute levels and relationships with height-for-age are substantially different than those previously observed in cohort studies of infants in The Gambia.     

Infants thinner at birth exhibit smaller kidneys for their size in late gestation in a sample of fetuses with appropriate growth

Fetal ultrasound measurements were employed to investigate the relationship between weight and ponderal index at birth and kidney size during the second (23 weeks) and third (32 weeks) trimesters of pregnancy in a sample of 25 normally growing fetuses. Kidney volume and kidney volume / fetal weight ratio at 32 weeks are significantly and positively related to both weight and ponderal index at birth, controlling for sex, gestational age at birth, and day of ultrasound measurement. A second‐degree polynomial relationship approximates the predictability of kidney volume fetal weight ratio at 23 weeks to that at 32 weeks, demonstrating shifting growth rates in fetal organ and body growth relationships during midgestation. Sex and parental size are suggested as contributing to these patterns. Females have a surge in renal growth between 23 and 32 weeks to catch up to earlier growing males, and maternal weight significantly predicts incremental growth in kidney volume and the kidney volume / fetal weight ratio at 32 weeks of gestation. The observation that fetuses relatively thin at birth have relatively smaller kidneys for their size in late gestation suggests that the influence of maternal weight on birth outcome may act through organ growth. Am. J. Hum. Biol. 14:398–406, 2002. © 2002 Wiley‐Liss, Inc.     

Effect of prenatal imipramine exposure on development of the postnatal rat heart and brain

Imipramine (IMI) was administered s.c. at 0, 5, or 10 mg/kg/day to pregnant rats on gestation days 8-20 to assess possible alterations in postnatal heart and brain development. Maternal weight gain was significantly reduced in a dose-response manner, but litter size and pup weight on postnatal day (PND) 1 were unaffected. On PND 1, litters were culled to 10 pups for analysis on PNDs 4/5, 7/8, 14/15, and 21/22. Pup body weight was not affected at any age measured, but heart weight was significantly reduced at 10 mg/kg IMI on PNDs 4/5 and 7/8. Brain weight was increased in a dose-related pattern on PNDs 4/5 and 7/8 and was significantly higher at 5 mg/kg IMI on PND 14/15. No significant effect was observed in heart or brain protein and DNA content or in cardiac beta-adrenergic receptor concentration. Prenatal IMI exposure had no effect on basal cardiac ornithine decarboxylase (ODC), an enzyme associated with growth and development, but basal brain ODC was lower at 5 mg/kg IMI at all ages measured. Cardiac ODC stimulation by insulin was unaffected by prenatal exposure to IMI, but isoproterenol-stimulated ODC was increased on PND 21/22 at 5 mg/kg IMI. In conclusion, the IMI-related changes in several parameters suggest that when maternal IMI treatment is used, alterations in postnatal heart and brain development must be considered as possible outcomes.     

Thymus weight changes during the early post-natal period in mice

Multiple regression analysis of the relationships of thymus weight to age and body weight, suggests that thymic growth patterns are widely variable and possibly are strain characteristics.     

A volumetric study of the corpus callosum in 20s and 40s Korean people

The purpose of this study was to measure the average corpus callosum volume of normal Koreans (aged in their 20s or 40s) and to analyze the effects of gender, age, and body parameters, such as height and weight on corpus callosum size. Magnetic resonance brain images were recorded for 68 people in their 20s (29 men, 39 women) and 91 in their 40s (36 men, 55 women). Intracranial volume was calculated using cerebral size and corpus callosum volume was normalized by covariance method. To investigate the effect of gender and age on corpus callosum volume, two-way analysis of variance, which used gender (two levels) and age (two levels) as independent variables, was employed. Multiple regression analysis was carried out to investigate the effect of body parameters, such as height and weight, according to the age and gender on the changes in corpus callosum volume. The average corpus callosum volume of Korean men (11.09 cm³) was larger than that of Korean women (9.61 cm³). There was no significant difference in corpus callosum volume between 20s (10.43 cm³) and 40s (10.12 cm³). There was a positive relationship between body weight and corpus callosum volume for 20s, but not for 40s.     

Effects of gender, age, and body parameters on the ventricular volume of Korean people

The purpose of this study was to measure the average ventricular volume of normal Koreans (aged in their 20s or 40s) and to analyze the effects of gender, age, and body parameters, such as height and weight on ventricle size. Magnetic resonance brain images were recorded for 118 people in their 20s (58 men, 60 women) and 100 in their 40s (41 men, 59 women). Using automatic and manual segmentation techniques, the volumes of the lateral and the third and fourth ventricles were calculated. To investigate the different and interactive effects of gender and age on ventricular volume, two-way analysis of variance (ANOVA) with gender and age as independent variables was carried out. Multiple regression analysis was used to investigate the effect of body parameters, such as height and weight according to gender on changes in ventricular volume. The average ventricular volume for people in their 20s was 16.2 cm3, and that for people in their 40s was 24.9 cm3. The average ventricular volume for men and women was 22.9 and 18.1 cm3, respectively. The average ventricular volume for men was greater than that for women, and that for people in their 40s was greater than that in their 20s. Enlargement of the ventricles on aging was more markedly observed in men than in women. There was a positive relationship between the body height and ventricular volume for men but not for women. There was no relationship between weight and ventricular volume for either men or women.     

Effect of increased growth rate during the suckling period on subsequent body weight and muscle weight to body weight ratio

The effect of increased growth rate during the suckling period on subsequent body growth rate and muscle weight to body weight (MW/BW) ratio was examined in inbred and outbred male and female mice. Growth rate during the suckling period was increased by reducing litter size to 4 pups within six hours of birth. Body weight, MW/BW ratio, and dry weight to wet weight (DW/WW) ratio for the soleus, tibialis anterior, extensor digitorum longus, biceps brachii, and heart muscles were measured at 4, 8, 16, and 24 weeks of age. The results indicate that increasing growth rate during the suckling period results in an increased body weight at 24 weeks of age in outbred male and female mice; whereas, in inbred male and female mice body weight is greater at 4 weeks of age but by 8 weeks of age the mice raised in normal litters have "caught up" with those raised in small litters. MW/BW ratio is increased in several muscles during the suckling period but returns to normal during the post weaning period.     

Effects of ketosis on glucose flux in children and adults

Sequential glucose flux studies were carried out in five normal and six epileptic children and ten adult volunteers using [6,6-2H2]glucose to determine the effect of ketosis on carbohydrate homeostasis in children and adults. All subjects were studied after 14 and 30-38 h of fasting while consuming a normal diet and the epileptic children under 14 h of fasting while consuming an isocaloric ketogenic diet (75% fat wt/wt). Glucose flux, when expressed per kilogram body weight, was inversely correlated with the degree of ketosis in children (P less than 0.001) and in adults (P less than 0.01), but not when both children and adults were considered together (r = 0.078). When glucose flux was corrected for estimated brain weight, the relationship between glucose flux and ketonemia was linearly related in children (P less than 0.001), in adults (P less than 0.02), and when all subjects were considered together (P less than 0.001). The inverse relationship between ketonemia and glucose flux corrected for estimated brain mass is consistent with a partial replacement of glucose by ketone bodies for cerebral metabolism and may provide a more rational means of expressing glucose flux data to take into account the higher brain-to-body ratio in children.     

The ontogenesis of skin and organ characteristics in the Syrian golden hamster. III. Ontogenetic and intraspecific allometry for strain and sex as well as body weight- and age-dependent correlations.

The allometric relations, i.e. bodily characteristics, body weight-relationships as well as age-dependent organ and biochemical data were studied in a total of 464 golden hamsters of both sexes of an acromelanic white inbred and agouti coloured outbred strain. In the 3 age sections studied (I = day 1-20, II = day 25-100, III = day 110-365) the body weight- and age-dependent relations were found to be altered between and within the various characteristics. The body weight correlations predominated in the case of organ weights and skin muscle thickness. By contrast, age correlations were seen above all in the skin compartments with cyclic growth, hair follicle density and reticular thickness in the age sections I and II. Papillary thickness showed a positive relation to body weight and age after weaning, but no long-term relations were observed with both plasma insulin and blood glucose levels. The allometric behaviour of skin compartments could be explained particularly by thermoregulatory and "geometric" similarities and that of the organs by metabolic and other similarities. Most sex and strain differences in the absolute data, except for the kidney and adrenal weights, disappeared on allometric analysis and were thus mainly due to differences in body weight. For long-term toxicological investigations, the documentation of age and body weight as well as the determination of ontogenetic allometry is a "must".     

Do Mid‐Crown Enamel Formation Front Angles Reflect Factors Linked to the Pace of Primate Growth and Development?

Enamel formation front (EFF) angles represent the leading edge of enamel matrix secretion at particular points in time. These angles are influenced by rates of enamel extension (the rates at which tooth crowns grow in height), rates of enamel matrix secretion and the angles that prisms make with the enamel‐dentine junction. Previous research suggests, but has not yet established, that these angles reflect aspects of primate biology related to their pace of growth and development, most notably brain and body size. The present study tested this possibility on histological sections using phylogenetically‐controlled and Bonferroni‐corrected analyses spanning a broad taxonomic range. Ten species were represented in the analysis of anterior teeth; 17 in the analysis of posterior (postcanine) teeth (with varying sample sizes). Also, tested was the relationship of EFF angles to striae of Retzius periodicity (long period growth rhythms in enamel) and degree of folivory, as both factors are related to primate developmental rates. Finally, several analyses were conducted to investigate whether tooth size (operationalized as EDJ length) might mediate these relationships. Central results are as follows: (1) Relationships between EFF angles and brain weight (anterior teeth) and between EFF angles and body mass (anterior and posterior teeth) are statistically significant and (2) Mid‐crown EFF angles are not statistically significantly related to EDJ lengths. These results suggest that tooth size does not mediate relationships between EFF angles and brain weight/body mass and are discussed with respect to underlying enamel growth variables (especially rates of enamel extension and secretion). Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:125–139, 2018. © 2017 Wiley Periodicals, Inc.     

In vivo effects of biosynthetic chicken growth hormone in broiler-strain chickens

Two experiments were conducted to examine the effects of growth hormone (GH) in growing chickens older than broiler age. In experiment 1, 8 week old male (heavy "broiler" type strain) chickens received daily injections of either biosynthetic chicken GH or an implant of biosynthetic bovine GH for 3 weeks. Neither growth rate (daily weight gain) nor the feed:gain ratio was influenced by either preparation of GH. However, an increase in breast muscle was observed in birds receiving the higher dose (250 micrograms/kg/day) of chicken GH. No changes were observed with chicken GH treatment on the weights of the fat pad, heart, gizzard and shank bone or on shank bone length or on plasma concentrations of free fatty acids. Experiment 2 employed 12 week old male, heavy strain, chickens with biosynthetic chicken GH being administered via Alzet osmotic pumps. In this study, GH (50 micrograms/kg/day) increased growth rate, body weight, pectoralis (breast) muscle weight, adipose tissue weight, bursa Fabricius weight and the plasma concentrations of free fatty acids. It is concluded that GH can influence carcass composition and growth in older chickens.     

Lung growth of the turkey,Meleagris gallopavo: I. Morphologic and morphometric description

To describe lung growth qualitatively and quantitatively from prehatch to adulthood of an unselected line of turkey, a precocial a avian species, 36 male turkeys, three in each age group, were killed at 22 and 25 days of incubation, on hatch day, and at 1, 4, 7, 10, 14, 21, 28, 112, and 420 days of age. Body weight and lung volume were measured. A three-level cascade sampling system was used to prepare lung tissue for morphologic and morphometric observation by light microscopy. Point and intersection counting were used to estimate volume and surface densities of lung compartments relative to lung volume. Absolute volumes and surfaces of lung compartments were calculated. Bilogarithmic regressions provided allometric equations to describe growth of the lung in three phases: (1) Tissue proliferation—explosive growth of lung volume relative to body weight and of the gas-exchange compartment within the lung. At 22 days of incubation there were few air and blood capillaries and a great deal of tissue that looked like mesenchyme between the parabronchin. Within the 6 days prior to hatch, the surface area of air capillaries increased 11-fold and of blood capillaries 27-fold, whereas the volume of interparabronchial tissue decreased 58%. (2) Equilibrated growth—from hatch day to 28 days of age, most lung compartments grew evenly with lung volume. (3) Regulated growth—from 28 days of age to adult, all lung compartments, except large vessels and exchange compartment, grew more slowly than the entire lung. Interatrial septa lengthened and their epithelial covering thinned, infundibula became more apparent, and interparabronchial connective tissue reached a minimal volume density in the adult lung.     

Longevity,mortality and body weight

The purpose of this study was to analyze the relation of total body weight to longevity and mortality. The MEDLINE database was searched for data that allow analysis of the relationship between absolute body weight and longevity or mortality. Additional data were used involving US veterans and baseball players. Trend lines of age at death versus body weight are presented. Findings show absolute body size is negatively related to longevity and life expectancy and positively to mortality. Trend lines show an average age at death versus weight slope of -0.4 years/kg. We also found that gender differences in longevity may be due to differences in body size. Animal research is consistent with the findings presented. Biological mechanisms are also presented to explain why increased body mass may reduce longevity. Life expectancy has increased dramatically through improved public health measures and medical care and reduced malnutrition. However, overnourishment and increased body size have promoted an epidemic of chronic disease and reduced our potential longevity. In addition, both excess lean body mass and fat mass may promote chronic disease.     

Increased brain weight/liver weight ratio as a necropsy sign of intrauterine undernutrition

Comparison of the brain weight/liver weight ratio(1) with the body weight of 95 stillborn and neonatally deceased infants of gestation 25-42 weeks shows that in appropriately grown infants the mean value ratio is 2.8 and is unchanged with increasing maturity. The normal range is 1.7-4.1. Survival time has no significant effect on the ratio as studied in this necropsy population. Dysmature infants of body weight less than 1 SD below the mean body weight for gestation are characterized by a brain: liver weight ratio of 4.5 or more. On the basis of these observations the brain: liver weight ratio may be employed as a guide to the prenatal nutrition of infants at necropsy.     

Brain growth in man

25 male brains meeting the criteria for normativity and available in serial sections suitable for morphometric studies were selected from the Yakovlev Collection. Growth parameters were calculated based on the generalized logistic function. The ideal weight is 1,313 g (SD = 41), with a half value time of 387 (SD = 26) ontogenetic days and a growth factor of 4.0 (SD = 0.5). Comparison of growth parameters derived from a sample of 161 normative male brains collected at the Department of Neuroanatomy of the Medical School in Hannover revealed an ideal weight of 1,353 g (SD = 14), a half value time of 401 (SD = 10) ontogenetic days and a growth factor of 4.0 (SD = 0.2). The minor discrepancies in the corresponding parameters reflect the small sample size and a considerable lack of developmental data of the three first postnatal decades in the material derived from the Yakovlev Collection. It was, therefore, deemed necessary to analyze these data in combination with data derived from other sources of human material. A comparison of human with animal growth parameters derived from mice, cats and tree shrews reveals differences in brain development. Histological shrinkage of the 25 male brains of the Yakovlev Collection related to fixation, embedding, and staining was assessed. Fetal brains shrank by about 75%, and adult brains by about 50%. The degree of shrinkage was inversely proportional to the age of the brain and was also characterized by individual variations of up to 20%. Therefore, shrinkage had to be corrected on an individual basis in order to determine the true growth of brain regions as reflected by morphometric analysis of histological serial sections.