Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Growth and Development”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 595 records · Page 33Linked to original sources
PubMed1984

Infectivity, growth and development of Echinostoma revolutum (Trematoda) in the domestic chick.

Infectivity, growth and development were studied in 23 one-day-old domestic chicks each fed 25 pre-selected metacercarial cysts of Echinostoma revolutum. All chicks were infected at necropsy one to 44 days post-exposure with one to 18 flukes/chick. From the 575 cysts fed to chicks, 145 (25%) flukes were recovered from the ileum, caeca, rectum-cloaca and bursa of Fabricius. Length measurements on 113 uncurled flukes fixed in hot alcohol-formalin-acetic acid showed that worms grew slowly to 1.0 mm by day 3, rapidly to 6 mm by day 14, and less rapidly to 9 mm by day 36. Worms became ovigerous by day 9. As worms aged in the chick, the body length increased relative to the width, the acetabulum shifted more anteriad and the size of the excretory bladder increased.

Animals↗
PubMed2003

Current perspectives on the role of thyroid hormone in growth and development of cerebellum.

The thyroid hormone (TH) is essential for growth and development of brain, including the cerebellum. Deficiency of TH during the perinatal period results in abnormal cerebellar development, which is well documented in rodent animal models. TH exerts its major effect by binding to the nuclear TH receptor (TR), a ligand-regulated transcription factor. Although TR is highly expressed in many brain regions, including the cerebellum, TH-target genes that likely play critical roles in brain development have not yet been fully clarified. At present, however, expression of many cerebellar genes is known to be altered by perinatal hypothyroidism. Interestingly, after the critical period of TH action (first 2 weeks of postnatal life in rodent cerebellum), the activities of many genes that are altered by perinatal hypothyroidism return to the same levels as those of euthyroid animal despite morphological alterations. Several prominent candidate genes that may play key roles in TH-mediated cerebellar development are discussed in this review. On the other hand, TR-mediated transcription may be modulated by various substances. The nuclear hormone receptor superfamily contains more than 40 transcriptional factors and, most of these receptors are present in the brain. Possible interactions between TR and such transcription factors are also discussed. Further, several additional issues that need to be clarified are discussed. One such issue is the discrepancy of phenotypes among TR-knockout and perinatal hypothyroid mice. Recent studies have provided several important clues to address this issue. Another current area that needs attention is the effect of endocrine disruptors on brain development. Since the molecular structures of TH and several endocrine disrupting chemicals are similar, the effect of such chemicals on brain may be exerted at least in part through the TH system. Recent studies have shown the possible interaction between TR and such chemicals. Overall, this review provides current findings regarding molecular mechanisms on TH action in cerebellar development.

Animals↗
PubMed1989

Effect of intracerebrally injected Corynebacterium parvum on the development and growth of metastatic brain tumor in mice.

Using KHT tumor in a mouse metastatic tumor model, we examined the effect of intracerebral and/or intraperitoneal injections of Corynebacterium parvum on the growth of metastatic brain tumor and the development of an inflammatory response in the central nervous system (CNS). C. parvum given intraperitoneally had no effect on the development and growth of CNS tumor, but did prolong the survival of mice by inhibiting the growth of systemic metastatic tumor, which was the cause of death in our tumor model. Mice that received intracerebral injections of C. parvum exhibited significantly decreased growth of metastatic brain tumor, as compared with mice that received intracerebral injections of saline, whether or not they had received C. parvum intraperitoneally. In addition, the brains of mice that received C. parvum intracerebrally exhibited an inflammatory response that was minimal or absent in the brains of control mice. Our results suggest that if immunotherapeutic agents can be delivered to the CNS and cause an inflammatory response, they can be effective against CNS metastases.

Animals↗
PubMed1996

Expression of the Agrobacterium rhizogenes rolC Gene in a Deciduous Forest Tree Alters Growth and Development and Leads to Stem Fasciation.

We have altered the growth and development of a deciduous forest tree by transforming hybrid aspen (Populus tremula x Populus tremuloides) with the Agrobacterium rhizogenes rolC gene expressed under the strong cauliflower mosaic virus 35S promoter. We demonstrate that the genetically manipulated perennial plants, after a period of dormancy, maintain the induced phenotypical changes during the second growing period. Furthermore, mass-spectrometrical quantifications of the free and conjugated forms of indole-3-acetic acid and cytokinins and several gibberellins on one transgenic line correlate the induced developmental alterations such as stem fasciation to changes in plant hormone metabolism. We also show that the presence of the RolC protein increases the levels of the free cytokinins, but not by a process involving hydrolysis of the inactive cytokinin conjugates.

Journal Article↗
PubMed1976

Secondary cartilages in growth and development of the symphysis menti in the hamster.

The early growth and development of the symphyseal joint and pertinent adjacent regions of the mandible in the hamster, Mesocricetus auratus, are described. The joint is patent throughout life and in adults contains a large fibrocartilage which mediates mandibular movements. Evidence is presented to show that this cartilage is formed by the fusion of Meckel's cartilage with two secondary cartilages that appear within the joint space. Evidence is also presented which suggests that cells of the symphyseal cartilage have the capacity to produce bone.

Aging↗
PubMed2000

Pharmacokinetic analysis of pegylated megakaryocyte growth and development factor in humans.

Phase I studies with pegylated megakaryocyte growth and development factor (PEG-rHuMGDF), a c-Mpl ligand that stimulates megakaryopoiesis, have demonstrated that PEG-rHuMGDF is biologically active alone and causes a dose-related enhancement of platelet recovery when administered after chemotherapy. Here we report the dose-ranging pharmacokinetics of PEG-rHuMGDF. Pre-injection blood samples were drawn daily for pharmacokinetic studies on 43 patients. An ELISA, established using PEG-rHuMGDF as the standard, was able to quantitate Mpl ligand at concentrations > 0.02 ng/mL. Over the dose range 0.03 to 5.0 microg/kg/day, subcutaneous administration produced linear increases in steady-state serum levels. Maximum levels of PEG-rHuMGDF attained after 5.0 microg/kg/day were 5.88 to 10.9 ng/mL. After discontinuation of PEG-rHuMGDF, concentrations of Mpl ligand returned to baseline within 5 days. The pharmacokinetics were best described by a one-compartment model with first-order absorption, an absorption delay, and non linear clearance over the first 48 hours. The mean terminal half-life was 33.3 + 16.7 hours, and the average apparent at steady state was 27.7 + 14.0 mL/h/kg; both were independent of administered dose. The apparent clearance of PEG-rHuMGDF was not predicted by platelet count. Administration of chemotherapy and Filgrastim did not alter the pharmacokinetics of PEG-rHuMGDF.

Antineoplastic Agents↗
PubMed2000

Influence of cadmium on growth and development of Vicia faba Linn.

Influence of cadmium (Cd) on growth and development of broad bean (V. faba) was assessed in pot cultures with cadmium iodide (CdI2) in different concentrations ranging from 15 to 500 mg per kg of soil. There was a decline in plant height and total dry weight. Root size decreased most significantly with a corresponding reduction in the frequency of root nodules. Total soluble protein in leaf, stem and root suffered a pronounced loss with increasing concentration of cadmium. Chlorophyll a was the most sensitive pigment followed by chlorophyll b and carotenoids. Nitrate reductase activity too was adversely affected. Cadmium contamination induced abnormalities in stomata and trichomes.

Cadmium↗
PubMed1995

Megakaryocyte growth and development factor ameliorates carboplatin-induced thrombocytopenia in mice.

Megakaryocyte growth and development factor (MGDF) administered intraperitoneally (IP) to mice causes a dose-dependent thrombocytosis accompanied by a decrease in mean platelet volume. MGDF increases the number of megakaryocytes in the bone marrow and spleen. MGDF does not affect the circulating number of leukocytes. Carboplatin, a chemotherapeutic agent that causes thrombocytopenia in humans, administered to mice as a single IP injection at a nonlethal dose causes a significant, but reversible thrombocytopenia. The carboplatin-induced thrombocytopenia is accompanied by an increase in circulating endogenous MGDF that precedes the return of circulating platelets to a normal level. MGDF mRNA is constitutively present in the liver. After carboplatin treatment, hepatic MGDF mRNA does not increase in concordance with circulating MGDF. Circulating soluble MGDF receptor levels (c-mpl) do not change significantly during the course of carboplatin-induced thrombocytopenia. MGDF injected IP once daily beginning 1 day after injection of carboplatin reverses carboplatin-induced thrombocytopenia in a dose-dependent fashion. The normalization of circulating platelet numbers in carboplatin plus MGDF-treated mice is accompanied by a normalization of megakaryocyte numbers in the bone marrow. In conclusion, MGDF, by increasing the number of marrow megakaryocytes and circulating platelets is an effective therapy for carboplatin-induced thrombocytopenia in mice.

Animals↗
PubMedDate not supplied

Growth and development in the rat during sub-chronic exposure to low levels of hydrogen sulfide.

The effects of low levels of hydrogen sulfide (H2S) on mammalian growth and development are unknown although it has long been postulated that H2S can inhibit critical developmental functions through the cleavage of disulfide bonds and chelation of essential metal ions. Gravid rat dams exposed to H2S (less than or equal to 75 PPM) from day 6 of gestation until day 21 postpartum (PP) demonstrated normal reproductive parameters until parturition. At parturition, however, delivery time was extended in a dose dependent manner with a maximum increase of 42% at 75 PPM. Maternal liver cholesterol content was elevated significantly on day 21 postpartum following exposure to 75 PPM H2S each day for 6 weeks. Pups which were exposed in utero and neonatally to day 21 postpartum developed with a subtle decrease in time of ear detachment and hair development and with no other observed change in growth and development through day 21 postpartum.

Animals↗
PubMed2001

The 'gold standard' for optimal fetal growth and development.

It is now becoming accepted that birth size per se is too crude an outcome measure to be used for the assessment of optimal intrauterine growth and development, and that a new vision of optimal fetal development is required for the 21st century. This will need to take account of both short- and long-term outcomes, to recognize that maternal body composition and diet can have long-term effects without necessarily affecting size at birth, and to take account of important interactions between the pre- and postnatal environments. At present, our understanding is limited and new definitions should only be considered as working hypotheses. Nonetheless, it is possible to begin to set out a framework for defining optimal fetal growth and development. This acknowledges the importance of developmental adaptations to alterations in the nutrient and hormonal milieu in utero and could have a major impact on human health in the century to come.

Embryonic and Fetal Development↗
PubMed1996

Pediatric growth and development.

Most children with congenital anomalies, teratogenesis, inborn errors of metabolism, and acquired toxicity or injury will have abnormal growth and development during the first few years of life. Many of the conditions are treatable, and early intervention is associated with improved prognosis. Developmental and growth assessment should be part of any routine visit to a primary care clinician. An overview of normal growth and development is outlined, and some common abnormalities are discussed.

Child↗
PubMed1986

Testosterone treatment of constitutional delay in growth and development: effect of dose on predicted versus definitive height.

The outcome of treatment in 3 groups of boys with constitutional delay in growth and development given monthly intramuscular injections of testosterone enanthate 200 mg (22 subjects) 100 mg (10 subjects) and 50 mg (12 subjects) was compared with the outcome in a control group (14 subjects) without treatment. The 4 groups were similar in chronological age, height, height age, bone age, height age/bone age ratio, pubertal development and had similar predicted adult heights. All treated subjects achieved an excellent growth response with growth velocities reflecting androgen dose. Bone age advanced commensurate with height age in all the treated groups and delta height age/delta bone age ratios at the end of therapy did not differ significantly. Nor was there a significant difference in the height prediction by the RWT method before and at the end of treatment. However, the year following treatment, growth velocities reversed so that those who received the largest steroid dose and had grown the fastest, decelerated the most and eventually ended up significantly shorter than their predicted adult height. In contrast the control group and those treated with smaller doses of testosterone achieved their predicted heights. The present study confirms that large doses of androgens compromise adult height and are contraindicated in the treatment of constitutional delay in growth and development. Testosterone enanthate 50 mg/mo did not affect predicted adult height adversely, but to the contrary, permitted it to be fully realised. The data caution against drawing conclusions based on changes observed during androgen therapy in the absence of extended follow-up.

Adolescent↗
PubMed2000

The place of Neandertals in the evolution of hominid patterns of growth and development.

This study uses the two developmental fields of dental maturation and femoral growth to determine if the pattern of growth and development in Neandertals (archaic Homo sapiens) was intermediate between that of Homo erectus and recent modern humans. Specimens used in the analysis included Neandertals and Upper Palaeolithic early modern Homo sapiens from Europe and individuals from two recent modern human populations. Ontogenetic data for the H. erectus adolescent KNM-WT 15000 and for Gorilla gorilla were included for comparison. Previous reports have indicated that H. erectus demonstrates a pattern of ontogeny characterized by earlier and more rapid linear growth than in modern humans. Results reported here demonstrate that Upper Paleolithic early modern Homo sapiens display a growth trajectory indistinguishable from that of recent modern humans. The pattern of Neandertal ontogeny is not intermediate between the pattern displayed in H. erectus and the derived pattern seen in the modern reference samples and the early modern H. sapiens sample. The Neandertal growth trajectory is consistent with either slow linear growth or advanced dental development.

Adolescent↗
PubMed1984

Calcitriol but no other metabolite of vitamin D is essential for normal bone growth and development in the rat.

To determine the relative importance of different metabolites of vitamin D in bone growth and development, weanling male rat pups suckled by vitamin D-deficient mothers were given either calcitriol (1,25-dihydroxycholecalciferol) by continuous subcutaneous infusion, oral calcidiol (25-hydroxycholecalciferol), or oral 24,24-difluoro-25-hydroxycholecalciferol, a synthetic compound that can undergo 1-hydroxylation but not 24-hydroxylation, as their sole source of vitamin D for 40 d. Pups raised in the same manner, but given no vitamin D, served as controls. The three metabolites compared were given in doses that restored normal plasma calcium levels and normal increments in body weight. After in vivo double tetracycline labeling, bone histomorphometry by standard methods was performed on one femur and one tail vertebra. There were no significant differences between the three metabolite-treated groups in length, periosteal or endosteal diameter, cortical cross-sectional area, cortical porosity, osteoid thickness and volume, appositional rate and bone formation rate in the femur, or in qualitative and quantitative indices of endochondral ossification in the tail vertebra. All three groups differed markedly from the untreated controls with respect to all measurements. Collectively, the data indicate that neither calcidiol nor any 24-hydroxylated metabolite of calcidiol is needed in the rat (other than as a precursor) for longitudinal or transverse bone growth, for normal endochondral ossification, or for normal periosteal and endosteal formation, mineralization, and resorption of bone. Calcitriol was fully active with respect to each of the indices listed when given in a manner resembling its continuous endogenous production by the kidney, suggesting that previous reports of incomplete skeletal response to calcitriol result from its rapid clearance and infrequent oral administration. We demonstrated that calcitriol is the only metabolite that is both necessary and sufficient for normal bone growth and development in the rat, but our data do not indicate the extent to which its beneficial skeletal effects were mediated by direct action on bone, either of calcitriol itself or of some metabolite thereof, or by restoration of normal plasma levels of calcium and phosphate.

Animals↗
PubMed1975

[Psychodynamic theory of childhood psychoses].

A review of the different concepts of childhood psychoses is made. Margaret Mahler's observations of normal and psychotic children concerning their relationship with their mothers during their first years of life are reviewed. Through the discussion of the concepts that Mahler has reached, understanding the dynamics of growth and their alterations, we obtain a clear understanding of the defects in psychological functions observed in the psychoses, including early infantile autism (Kanner) and symbiotic psychosis (Mahler). A correlation of events occurring at different levels of growth: object relations, cognitive growth, psychosexual development, growth of anxiety, etc., is attempted.

Child↗
PubMed2004

Nuclear hormone receptor coregulator: role in hormone action, metabolism, growth, and development.

Nuclear hormone receptor coregulator (NRC) (also referred to as activating signal cointegrator-2, thyroid hormone receptor-binding protein, peroxisome proliferator activating receptor-interacting protein, and 250-kDa receptor associated protein) belongs to a growing class of nuclear cofactors widely known as coregulators or coactivators that are necessary for transcriptional activation of target genes. The NRC gene is also amplified and overexpressed in breast, colon, and lung cancers. NRC is a 2063-amino acid protein that harbors a potent N-terminal activation domain (AD1) and a second more centrally located activation domain (AD2) that is rich in Glu and Pro. Near AD2 is a receptor-interacting domain containing an LxxLL motif (LxxLL-1), which interacts with a wide variety of ligand-bound nuclear hormone receptors with high affinity. A second LxxLL motif (LxxLL-2) located in the C-terminal region of NRC is more restricted in its nuclear hormone receptor specificity. The intrinsic activation potential of NRC is regulated by a C-terminal serine, threonine, leucine-regulatory domain. The potential role of NRC as a cointegrator is suggested by its ability to enhance transcriptional activation of a wide variety of transcription factors and from its in vivo association with a number of known transcriptional regulators including CBP/p300. Recent studies in mice indicate that deletion of both NRC alleles leads to embryonic lethality resulting from general growth retardation coupled with developmental defects in the heart, liver, brain, and placenta. NRC(-/-) mouse embryo fibroblasts spontaneously undergo apoptosis, indicating the importance of NRC as a prosurvival and antiapoptotic gene. Studies with 129S6 NRC(+/-) mice indicate that NRC is a pleiotropic regulator that is involved in growth, development, reproduction, metabolism, and wound healing.

Animals↗
PubMed1978

Improved student learning of infant growth and development.

All physicians who care for children require a knowledge of normal growth and development in order to detect and interpret abnormalities. Yet traditional instruction tends to focus on the ill child and rarely provides students the opportunity to follow up the cases of healthy children over a prolonged period of time. A new course was developed that enabled students to observe the longitudinal developmemt of a normal infant from birth to age 16 months. At the completion of the course, a multiple-choice examination covering developmental concepts from birth to age 6 years was administered to the students who participated in this course (experimental group) and to two comparison groups. The experimental group scored substantially higher than both comparison groups on items covering birth to age 18 months. The program offers an opportunity for medical students to observe the longitudinal development of a normal infant and appears complementary to other instructional methods.

Arizona↗