Patterns of cephalofacial growth and development. A comparative study of the basicranial growth centers in rat and man.
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Animals↗
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Heterogeneous growth and mental development of intrauterine growth-retarded infants during the first 3 years of life.
Postnatal growth and development were studied in two groups of term infants with intrauterine growth retardation (IUGR) and one group of infants with normal birth weight up to 3 years of age (total sample, 205 infants). Infants with IUGR were classified as having low ponderal index (IUGR-LPI) or adequate ponderal index (IUGR-API). At birth, the two groups of infants with IUGR had similar birth weight, but length and head circumference measurements were significantly different. Overall, the IUGR-API infants remained lighter and shorter and had smaller head circumferences up to 30 months of age. The IUGR-LPI infants experienced catch-up growth in weight during the first months, because of greater fat deposition. At 24 months of age, the IUGR-API infants scored below the others on mental items. At 3 years of age the IUGR-API infants had the lowest values on seven of eight developmental measures and on the composite score; at these two time periods, the group with normal birth weight scored the highest, and the IUGR-LPI infants obtained intermediate values. It is concluded that infants with IUGR tend to follow postnatal growth and developmental patterns that are associated with their physical characteristics at birth.
Body Height↗
Modification of plant growth and development by acceleration and vibration: concerns and opportunities for plant experimentation in orbiting spacecraft.
Growth, development, and orientation of higher plants is altered by physical disturbances such as shaking, touching, or vibration. Plant growth responses to thigmic (contact rubbing) forces are almost always negative, whereas growth responses to periodic seismic (shaking) or vibric (vibrational) disturbances may be positive or negative, depending on intensity and duration of force, and prevailing environmental conditions. Seedlings are most sensitive to mechanical stress when grown in darkness or under the low-light conditions typically available in plant flight hardware. Brief exposure to physical perturbation causes immediate growth inhibition of dark-grown seedlings followed by gradual recovery of growth rate beginning 10-12 minutes later. For mild vibration, growth rate may overshoot that of undisturbed control plants within an hour of a stress episode, whereas for thigmic stress recovery may remain incomplete for 24 hours or longer. Lack of physical stimulation by gravity should make plants even more responsive to random physical perturbation. Threshold growth response of seedlings to vibrational parameters needs to be determined under real spaceflight conditions.
Acceleration↗
Growth hormone releasing hormone expression during postnatal development in growth hormone-deficient Ames dwarf mice: mRNA in situ hybridization.
Several genetic mutations in mice and rats that produce lifelong growth hormone (GH) deficiency result in overexpression of GH-releasing hormone (GHRH) mRNA in hypothalamic arcuate nucleus neurons. In order to examine the development of this condition, GHRH mRNA expression was quantified in Ames dwarf (df/df) and normal (DF/?) mice at 1 (day of birth), 3, 7, 14, 21 and 60 postnatal days (d) following in situ hybridization. Total mRNA was assessed using computer-assisted densitometry after X-ray film autoradiography, and mRNA expression per neuron was quantified by counts of grains per cell after emulsion autoradiography. Total GHRH mRNA was the same in dwarf and normal mice at 1, 3 and 7d. GHRH mRNA in dwarfs increased at 14d to 240% of that in DF/? (p < 0.005); the percentage overexpression in dwarf mice remained >/=200% through 60d, although total GHRH mRNA increased in both dwarfs and normals during this period. GHRH mRNA per neuron was the same in normal and dwarf mice at 1d, then increased in dwarfs to 190% of that in normals at 3d (p < 0.05), and rose to 300% of normal levels by 7d and beyond (p < 0. 005). There was no sexual dimorphism in expression by either measure in normal or dwarf mice. These results indicate that an increase in GHRH mRNA in Ames dwarf mice is first detectable at 3d, a period of approximately 7d after the failure to initiate GH production, which occurs normally at embryonic day 17.5. The onset of GHRH overexpression occurs earlier than the decline of either hypophysiotropic somatostatin or dopamine in Ames dwarf mice. This difference may be due to the stimulatory action of GHRH, as opposed to the inhibitory effects of factors examined previously.
Animals↗
Dietary polyamines are essential luminal growth factors for small intestinal and colonic mucosal growth and development.
BACKGROUND: Polyamines are essential for cell growth. Dietary and probably gut bacterial derived polyamines contribute significantly to the polyamine body pool. AIMS: To evaluate the influence of dietary, luminal polyamines on growth and development of different gastrointestinal organs in normally growing rats. METHODS: Male suckling Wistar rats were randomly allocated to four treatment groups: polyamine deficient diet (PDD); PDD plus antibiotics (neomycin 2 g/kg and metronidazole 34 mg/kg); PDD plus polyamine supplementation at normal concentrations; or normal standard laboratory chow. After a six month feeding period 7-10 animals/group were sacrificed. RESULTS: No differences in body weight gain, food consumption, or general behaviour could be observed between the four groups of animals. Feeding of PDD alone or PDD plus antibiotics resulted in a highly significant decrease in organ weight, protein content, and DNA content in small intestinal and colonic mucosa whereas no alterations were found in the liver. CONCLUSIONS: Long term feeding of polyamine deficient diets resulted in a significant hypoplasia of small intestinal and colonic mucosa. Dietary, luminal polyamines are important local factors for growth and the development of small intestinal and colonic mucosa.
Animal Nutritional Physiological Phenomena↗
Physiologic changes during growth and development.
To express growth-related changes in physiologic or other functions in forms usable for kinetic modeling, we are interested in identifying regular relationships that take the form of simple mathematical expressions. Many anatomic and physiologic functions scale within or across species in accordance with the allometric relationship, y = axb. These include many organ weights, the glomerular filtration rate, respiration rate, oxygen consumption, or basal metabolic rate. The allometric lines may display discontinuities in slope associated with critical growth periods such as transitions from one growth phase to another. On the other hand, many other kinetically important processes depend on the physiocochemical characteristics of the agent and of the sites in the body with which it interacts. Their rates of development are determined by the age-dependence of these physiocochemical characteristics and of their interactions. Examples of different types of age-dependence are given, and their combined impact on the age-dependence of lead-kinetic behavior is examined.
Adolescent↗
Influence of whorl region from resistant and susceptible corn genotypes on fall armyworm (Lepidoptera: Noctuidae) growth and development.
The effect of diets prepared from whorl tissue of resistant and susceptible corn genotypes, Zea mays L., on the larval growth, development, and physiology of fall armyworm, Spodoptera frugiperda (J. E. Smith), was analyzed. Larvae reared on an optimized artificial diet had a higher growth rate and developed faster than those reared on lyophilized whorl tissue from resistant and susceptible genotypes. Larvae reared on the resistant material were smaller and had a longer developmental period. Larvae reared on yellow-green and green whorl sections from resistant plants were significantly smaller than those reared on the same sections of susceptible plants. There was no significant difference in weight when larvae were reared on the yellow whorl regions from either resistant or susceptible lines. Physiological indices were determined for larvae fed resistant and susceptible lyophilized and fresh whorl material. Larvae fed resistant lyophilized material had significantly lower growth rate (GW) and efficiency of conversion of ingested food to body substance (ECI) than those reared on artificial diet or susceptible material. However, there were no significant differences in consumption index (CI), approximate digestibility (AD) and efficiency of conversion of digested food to body substance (ECD) between larvae reared on lyophilized tissue from resistant and susceptible genotypes. Larvae reared on fresh yellow-green whorl sections from resistant plants had significantly lower GW, ECI, and ECD than those reared on susceptible material. In contrast, no significant differences in any of the estimated food consumption and utilization indices were observed between larvae reared on fresh yellow whorl sections from resistant or susceptible plants. These results suggest that some components of whorls from resistant plants, especially the yellow-green region, inhibit food utilization in fall armyworm larvae.
Animals↗
Growth and development of Haemonchus contortus in jirds, Meriones unguiculatus.
Growth and development of Haemonchus contortus were examined in jirds and were compared to these processes in lambs. Number, sex, size, and stage of development were determined for worms recovered at necropsy at various times postinoculation (PI) from immunosuppressed jirds inoculated with approximately 1,000 exsheathed infective larvae (L3) of H. contortus. In addition, gastric tissue samples from jirds were examined histologically. Parallel studies were done in lambs inoculated with approximately 7,500 L3. Typically, 5-30% of the inoculum established and survived in jirds at reasonably stable numbers to day 14 PI. By day 21 PI, worm numbers in jirds decreased dramatically. Although the parasite was similar in size and development on day 4 PI in jirds and lambs, from day 7 PI on, worms were significantly smaller and less developed in jirds. On histological examination, the parasite was found only in the glandular portion of the stomach of jirds (anatomically similar to its predilection site in the abomasum of lambs), and histological changes were consistent for both host species. Although growth and development of H. contortus are slower and incomplete in jirds, the parasite establishes, grows, and develops (at anatomically comparable sites in both hosts) in this model. Thus, the model appears to provide a useful laboratory host to study H. contortus.
Abomasum↗
Discordance of congenital bilateral anorchia in uniovular twins: 17 years of observations on growth and development.
We have reported observations of growth and development made over a 16-year period on a subject who suffered bilateral congenital anorchia and his uniovular twin brother. The anorchic individual was treated with oxandrolone for a period of 3.6 years prior to the testosterone replacement therapy. The oxandrolone therapy produced a significant increment in the height age without excessive gain in bone age. At the age of 20.9 years the anorchic twin is 5.4 cm taller than his normal twin. Other differences observed between the twins reported here include the following: the anorchic subject had longer extremities, greater biacromial and biiliac distances and a smaller penis than his normal sibling. Oxandrolone therapy does appear to modify the ultimate height in children.
Adolescent↗
Early Australian clinical studies with pegylated recombinant human megakaryocyte growth and development factor.
Pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF, an Mpl ligand) is a truncated form of native thrombopoietin currently undergoing clinical development. A series of studies in Australia have examined the safety and biological activities of PEG-rHuMGDF. Administration of PEG-rHuMGDF causes a dose-dependent increase in platelet count but has no effect on white cell count or hematocrit. These platelets are morphologically and functionally normal. When administered following moderately myelosuppressive chemotherapy, PEG-rHuMGDF significantly enhances platelet recovery, although scheduling in relation to chemotherapy may be important in optimizing the full effects. PEG-rHuMGDF mobilizes progenitor cells of multiple hematopoietic lineages, and alters the kinetics of peripheral blood progenitor cell mobilization after chemotherapy and filgrastim. PEG-rHuMGDF is well tolerated and does not cause toxicity similar to that observed with other thrombopoietic cytokines. Numerous studies are underway to help determine the precise role of PEG-rHuMGDF in clinical practice.
Australia↗
Cloning and characterization of the human megakaryocyte growth and development factor (MGDF) gene.
The megakaryocyte growth and development factor (MGDF) is a cytokine that regulates megakaryocyte development and is a ligand for the MPL receptor. In this study, we describe the genomic structure of the human MGDF gene. The MGDF gene was found to consist of seven exons and six introns spanning 8 kilobases. The protein is encoded by exons 3 through 7. The human MGDF gene has been mapped to chromosome 3q26.3. In addition to the previously described full-length cDNA, two cDNA variants were isolated from human fetal liver. Comparison of these two cDNA sequences with the genomic sequence indicates that they arise by differential splicing.
Amino Acid Sequence↗
The murine N-ras gene is not essential for growth and development.
The mammalian ras gene family encodes key cell-signaling, cell growth-related proteins that have been highly conserved in species from yeast to man. Specific point mutations in the ras genes are associated with various mammalian tumors. To understand the developmental role of the N-ras protooncogene in the mouse, we have disrupted its gene function by homologous recombination in embryonic stem cells. Mice derived from these cells that are homozygous for the N-ras mutation do not produce any detectable N-Ras protein and are morphologically and histologically indistinguishable from their heterozygous and wild-type siblings. Since N-ras is expressed at high levels in hematopoietic cells, we examined different populations of cells in peripheral blood and found no differences between mutant and normal animals. Our results show that N-ras gene function is dispensable for normal mouse development, growth, and fertility.
Animals↗
Effects of lactogenic hormones on morphological development and growth of human breast epithelial cells cultivated in collagen gels.
We investigated the hormonal dependence of the growth and morphological development of human breast epithelial cells (HBEC) cultivated in collagen gels floating on serum-free medium. HBEC used had grown out from breast carcinoma tissue and from histologically non-malignant tissue fragments in the same mastectomy specimens. In the presence of all three lactogenic hormones, hydrocortisone (HC), insulin (INS), and prolactin (PRL), both carcinoma-derived and histologically non-malignant tissue-derived HBEC grew and formed cell masses with protruding tubule-like extensions that consisted of a multilayer of cells. Deletion of any one of the hormones from the medium had no effect on cell growth of HBEC derived from either tissue type. However, morphological development, especially the morphology of the tubule-like extensions, was altered in the histologically non-malignant tissue-derived HBEC by deletion of HC or INS, and by deletion of HC, but not INS, in the carcinoma-derived HBEC. The present results suggest that the carcinoma-derived HBEC have decreased responsiveness to INS as compared to that of HBEC derived from histologically non-malignant breast tissue.
Breast↗
Long-term growth and development in children after home parental nutrition.
Growth and development after the cessation of prolonged parenteral nutrition (PN) has not been fully evaluated. Growth, body composition, and nutritional and developmental status were documented in nine children (five boys, four girls) 2 to 6 years old (mean 4.9 +/- 1.0 years) who had previously received long-term PN (mean 14.6 +/- 11.4 months). PN had been discontinued in all subjects for at least 6 months (mean 3.4 +/- 1.4 years); they were receiving oral feedings only. One subject had a significantly low height-for-age, and another had a low percent ideal body weight; five subjects had low total body fat. Serum vitamin A was low in six subjects. Seventy-two-hour fecal fat analysis was abnormal in two of eight subjects. Abnormal bone mineral density was present in four of nine subjects. Psychomotor development was normal in all nine subjects. Two had functional difficulties in swallowing. One or more abnormalities were present in all nine subjects. These findings suggest that children who require prolonged PN in early life are at risk for abnormalities in growth and nutritional status in later childhood; they require long-term dietary, growth, and nutritional monitoring.
Anthropometry↗
Platelet-derived growth factor: its potential roles in wound healing, atherosclerosis, neoplasia, and growth and development.
Platelet-derived growth factor (PDGF) has been found to be derived not only from platelets that have been induced to release their contents, but also from a number of transformed cells (including cells transformed by both DNA and RNA viruses, spontaneous transformation, and cells from various human tumours), from activated macrophages, from embryonic rat aortic smooth muscle cells, and from rat aortic smooth muscle cells derived from experimentally induced intimal proliferative lesions. The studies discussed demonstrate the potential role of platelets and macrophages in atherosclerosis and in wound repair, and indicate the ability of anti-PDGF IgG to inhibit proliferative responses in vitro. With the demonstration that the transforming protein derived from the oncogene from the simian sarcoma virus is highly homologous with PDGF, it was possible to show that a number of transformed cells secrete PDGF and show markedly decreased binding of PDGF. The same is true for embryonic rat aortic smooth muscle cells and for cells from experimentally induced proliferative lesions in the rat carotid artery. All these findings point to the role of PDGF in the formation of these lesions and can be correlated with the capacity of the cells noted above, as well as injured endothelial cells, to secrete PDGF or PDGF-like molecules. The biological significance of these observations is discussed and a model for atherogenesis is proposed.
Animals↗
Growth and development in rats given recombinant human epidermal growth factor(1-48) as neonates.
To assess effects of supraphysiologic doses of human recombinant epidermal growth factor(1-48) (rhEGF(1-48)) on neonatal rats, 10 litters of Wistar rats/treatment group were given 0 (formulated vehicle), 10, 100, or 1000 microg/kg daily by subcutaneous injection on postnatal days (PND) 1 through 6. Clinical signs, body weight, acquisition of developmental landmarks and reflexes, and behavior were monitored during treatment and for 5 weeks thereafter (to PND 42). A subset of animals was euthanized weekly from PND 7-28 and necropsied. Selected tissues were examined microscopically. Body weight gain at 1000 microg/kg during treatment was significantly less than control. Precocious incisor eruption, eye opening, vaginal opening, and preputial separation occurred at 100 and/or 1000 microg/kg. Acquisition of reflexes (negative geotaxis, wire maneuver, acoustic startle reflex, and visual placing) was delayed at 1000 microg/kg. Acquisition of adult locomotion was also delayed at 1000 microg/kg. These effects were transient, as locomotor activity at PND 28 and 42 did not differ from control. Effects on acoustic-startle responding persisted in females to final assessment on PND 42. Habituation to repeated acoustic stimuli was impaired, as well as response inhibition following a prepulse acoustic stimulus. rhEGF(1-48) induced structural changes in the skin, retina, kidney, oral and nasal mucosa, lung, and liver. Many of these changes were consistent with the expected mitogenic activity of rhEGF(1-48) and were transient in nature, as severity and incidence diminished with time. An exception was changes observed in the retina at 1000 microg/kg (rosettes/folds and focal defects in the outer nuclear/photoreceptor layers) that were still present 3 weeks after termination of treatment. Acceleration of developmental landmarks; suppression of reflexes, behavior, and somatic growth; and mitogenic responses in epidermal tissues have been reported in rodents treated with epidermal growth factor (EGF) derived from various mammalian species. These results demonstrate that a 48-amino acid fragment of human EGF produced by recombinant technology also induces such effects.
Acoustic Stimulation↗
Effects of prenatal ethanol and long-chain n-3 fatty acid supplementation on development in mice. 1. Body and brain growth, sensorimotor development, and water T-maze reversal learning.
Pregnant mice were fed equivalent daily amounts of a liquid diet containing 25% (kcal) ethanol, or with maltose dextrin substituted isocalorically for ethanol. In addition, the diet contained 20% oil; this was either of two mixtures, one comprised of predominantly n-6 (18:2n-6) fatty acids, and the other containing an equivalent amount of n-6, but supplemented with a source of long chain n-3 (20:5n-3, 22:6n-3) fatty acids. An additional control group was fed lab chow ad libitum. The treatment was implemented from day 7 to 17 of gestation, whereafter all groups were fed lab chow. Ethanol decreased maternal weight gain and pup body and brain weight; it also retarded both sensory and motor development in the pups and impeded reversal learning in a water maze. The n-3 supplementation lowered maternal blood alcohol concentration, but counteracted only some of the effects of ethanol, by increasing maternal weight gain and pup body weight, and also by enhancing sensory development in the pups. Such effects were additive, in that they were also present in the maltose-dextrin control group. These findings suggest that n-3 supplementation may ameliorate some of the effects of ethanol on neurobehavioral development, but the magnitude of the effect appears to be small.
Animals↗
Increased expression of insulin-like growth factor I and/or its receptor in gastrinomas is associated with low curability, increased growth, and development of metastases.
PURPOSE: Growth factors, particularly insulin-like growth factor I (IGF-I) and IGF-I receptor (IGF-IR) in some nonendocrine and a few endocrine tumors, are thought important in recurrence, growth, and aggressiveness. Whether this is true of neuroendocrine tumors such as gastrinomas is unclear. The aim of this study was to address this question in gastrinomas. EXPERIMENTAL DESIGN: IGF-I and IGF-IR expression in gastrinomas from 54 patients with Zollinger-Ellison syndrome were analyzed and correlated with clinical/tumor characteristics. IGF-I and IGF-IR mRNA levels were determined by competitive reverse transcription-PCR. IGF-IR expression, assessed by immunohistochemistry, was done on a subset. RESULTS: IGF-IR mRNA was found in 100% and IGF-I in 89%. IGF-I mRNA expression varied by >254-fold, IGF-IR by 2,670-fold, and the levels correlated in a given tumor. The IGF-IR level was lower in gastrinomas of patients who were rendered disease free and increased levels correlated with tumor growth, aggressiveness, extent, and with liver metastases. Increased IGF-I levels correlated with increased growth, tumor extent, and aggressiveness. Neither IGF-IR nor IGF-I levels correlated with tumor location, size, or its clinical/functional features. The IGF-IR correlated with disease-free survival. IGF-IRbeta was found in 31 of 32 tumors (97%) by immunohistochemistry. CONCLUSIONS: These results indicate that IGF-I and IGF-IR are expressed in almost all gastrinomas. Furthermore, assessment of IGF-I/IGF-IR expression in gastrinomas may be clinically useful in identifying those patients with more aggressive tumors who might benefit from more aggressive treatment.
Adolescent↗