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Increased Growth Rate (increased + growth_rate)
Selected AbstractsIs treatment with growth hormone effective in children with cerebral palsy?DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 8 2004Melanie L Shim MD Children with cerebral palsy (CP) often have poor linear growth during childhood, resulting in a diminished final adult height. Here we report a female with CP and short stature but without growth hormone (GH) deficiency who exhibited increased growth during treatment with GH. We also report two other children with CP who were treated with GH: one female with a history of leukemia, and a male with Klinefelter syndrome. These two children were both found to be GH-deficient by insulin provocative GH testing and responded to treatment with increased growth rate. Growth improved to a greater extent in the two children with apparent GH deficiency. In summary, it is felt that GH therapy might be beneficial for children with CP and warrants further investigation. [source] THE EVOLUTION OF SPECIFICITY IN EVOLVING AND COEVOLVING ANTAGONISTIC INTERACTIONS BETWEEN A BACTERIA AND ITS PHAGEEVOLUTION, Issue 1 2008Virginie Poullain The evolution of exploitative specificity can be influenced by environmental variability in space and time and the intensity of trade-offs. Coevolution, the process of reciprocal adaptation in two or more species, can produce variability in host exploitation and as such potentially drive patterns in host and parasite specificity. We employed the bacterium Pseudomonas fluorescens SBW25 and its DNA phage ,2 to investigate the role of coevolution in the evolution of phage infectivity range and its relation with phage growth rate. At the phage population level, coevolution led to the evolution of broader infectivity range, but without an associated decrease in phage growth rate relative to the ancestor, whereas phage evolution in the absence of bacterial evolution led to an increased growth rate but no increase in infectivity range. In contrast, both selection regimes led to phage adaptation (in terms of growth rates) to their respective bacterial hosts. At the level of individual phage genotypes, coevolution resulted in within-population diversification in generalist and specialist infectivity range types. This pattern was consistent with a multilocus gene-for-gene interaction, further confirmed by an observed cost of broad infectivity range for individual phage. Moreover, coevolution led to the emergence of bacterial genotype by phage genotype interactions in the reduction of bacterial growth rate by phage. Our study demonstrates that the strong reciprocal selective pressures underlying the process of coevolution lead to the emergence and coexistence of different strategies within populations and to specialization between selective environments. [source] The development and endophytic nature of the fungus Heteroconium chaetospiraFEMS MICROBIOLOGY LETTERS, Issue 2 2005Teruyoshi Hashiba Abstract The root endophytic fungus Heteroconium chaetospira was isolated from roots of Chinese cabbage grown in field soil in Japan. This fungus penetrates through the outer epidermal cells of its host, passes into the inner cortex, and grows throughout the cortical cells, including those of the root tip region, without causing apparent pathogenic symptoms. There are no ultrastructural signs of host resistance responses. H. chaetospira has been recovered from 19 plant species in which there was no disruption of host growth. H. chaetospira has a symbiotic association with Chinese cabbage. The fungus provides nitrogen in exchange for carbon. These associations are beneficial for the inoculated plants, as demonstrated by increased growth rate. When used as a preinoculum, H. chaetospira suppresses the incidence of clubroot and Verticillium yellows when the test plant is post-inoculated with the causal agents of these diseases. H. chaetospira is an effective biocontrol agent against clubroot in Chinese cabbage at a low to moderate soil moisture range and a pathogen resting spore density of 105 resting spores per gram of soil in situ. Disease caused by Pseudomonas syringae pv. macricola and Alternaria brassicae on leaves can be suppressed by treatment with H. chaetospira. The fungus persists in the roots and induces systemic resistance to the foliar disease. [source] Changes in vertebral structure during growth of reared rainbow trout, Oncorhynchus mykiss (Walbaum): a new approach using modelling of vertebral bone profilesJOURNAL OF FISH DISEASES, Issue 3 2009M-H Deschamps Abstract Severe bone resorption of the vertebral body in reared rainbow trout was thought to be a dysfunction in mineral balance induced by increased growth rate in unfavourable rearing conditions. To verify this assumption, we sampled market-sized trout (c. 250 g) from 20 fish farms with different rearing conditions. Growth rate was also studied by sampling trout reared in three different water temperatures from fry to market-size. Transverse sections of vertebrae were microradiographed, then digitized. Total bone area (Tt-B.Ar.) and bone profiles were obtained using BONE PROFILER 3.23 software and a mathematical model was developed to statistically compare bone profiles using 12 parameters in four vertebra regions. Tt-B.Ar. and bone profiles were found to vary with rearing conditions and growing temperatures, indicating obvious influences of these factors on bone remodelling. However, vertebral resorption was found to be a general phenomenon. In trout from 190 to 235 mm in length, vertebrae underwent important remodelling resulting in large resorption of the middle area, while the transition and peripheral areas showed an increase in bone deposition. Changes in vertebra architecture seem to be a good compromise between the need to mobilize stored minerals during growth while maintaining vertebral biomechanical properties. [source] Expression of a Rho Guanine Nucleotide Exchange Factor, Ect2, in the Developing Mouse PituitaryJOURNAL OF NEUROENDOCRINOLOGY, Issue 5 2010M. S. Islam The pituitary gland is a highly mitotically active tissue after birth. Various cell types are known to undergo proliferation in the anterior pituitary. However, little is known about the mechanisms regulating mitotic activity in this tissue. When searching for genes specifically expressed in the pituitary gland among those that we previously screened in Drosophila, we found epithelial cell-transforming gene 2 (Ect2). Ect2 is a guanine nucleotide exchange factor for Rho GTPases, which is known to play an essential role in cytokinesis. Although there have been many cellular studies regarding the function of Ect2, the temporal and spatial expression patterns of Ect2 in vivo have not been determined. In the present study, we examined the postnatal developmental expression of Ect2 in the mouse pituitary. Enhanced Ect2 expression was detected in the mouse pituitary gland during the first 3 weeks after birth, which coincided well with the period of rapid pituitary expansion associated with increased growth rate. Immunostaining analysis showed that Ect2-expressing cells were distributed in the anterior and intermediate lobes, but not the posterior lobe, of the pituitary. These Ect2-expressing cells frequently incorporated the thymidine analogue, EdU (5-ethynyl-2,-deoxyuridine), indicating that these cells were mitotically active. Taken together, the results demonstrate the functional role of Ect2 in postnatal proliferating cells in the two lobes of the pituitary, thereby suggesting roles in developmental growth of the mammalian pituitary. [source] Osteopontin Mediates Dense Culture-Induced Proliferation and Adhesion of Prostate Tumour Cells: Role of Protein Kinase C, p38 Mitogen-Activated Protein Kinase and CalciumBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 2 2009Hong Zhou Our results demonstrate that increasing cell density exerted stress on PC-3M cells, which decreased cell proliferation in dense cultures, but tended to facilitate tumour metastasis since cell adhesion ability was elevated and the cells showed an increased growth rate after being moved to a favourable growth environment. We conclude that higher cell density-mediated pericellular hypoxia was an important factor inducing expression of the intrinsic hypoxia marker osteopontin, another mechanism contributing to cell adhesion enhancement in PC-3M cells. In addition, cell density enhanced adhesion ability due to the activation of p38 mitogen-activated protein kinase (p38 MAPK) and protein kinase C. Intracellular calcium also played positive roles at least partially through activating p38 MAPK. [source] Small-scale fluid motion mediates growth and nutrient uptake of Selenastrum capricornutumFRESHWATER BIOLOGY, Issue 6 2006T. A. WARNAARS Summary 1. A fluid-flow reactor using submersible speakers was constructed to generate small-scale fluid motion similar to conditions measured in open water environments; flow was quantified by particle image velocimetry. Additionally a Couette-type rotating cylinder was used to generate shear flows; flow was quantified using an optical hotwire probe and torque measurements. Growth rates of the green alga Selenastrum capricornutum were determined from changes in cell counts and viability was tested using the fluorogenic probe fluoresceine diacetate. 2. Evidence that fluid motion directly affects growth rates was obtained as a significant difference between growth in a moving versus non-moving fluid. A near 2-fold increase in growth rate was achieved for an energy dissipation rate of , = 10,7 m2 s,3; a rate common in lakes and oceans. The onset of the viability equilibrium, identified as the day of the test period when the number of active cells equalled non-active cells, was delayed by 2 days for moving fluid conditions as compared with a non-moving fluid. 3. Nutrient uptake was determined by a decrease in the bulk fluid concentration and cellular phosphorus concentration was also estimated. The thickness of the diffusive sublayer surrounding a cell, a zone dominated by molecular diffusion, was estimated. Increasing fluid motion was found to decrease the thickness of this layer. The Sherwood number (ratio of total mass flux to molecular mass flux) showed that advective flux surrounding cells dominated molecular diffusion flux with regard to Péclet numbers (ratio of advective transport to molecular diffusion transport). Fluid motion facilitated uptake rates and resulted in increased growth rates, compared with no-flow conditions. The rate-of-rotation and the rate-of-strain in a moving fluid equally mediated the diffusive sublayer thickness surrounding the cells. Our study demonstrates that small-scale fluid motion mediates algal growth kinetics and therefore should be included in predictive models for algal blooms. [source] Size-specific growth of bluegill, largemouth bass and channel catfish in relation to prey availability and limnological variablesJOURNAL OF FISH BIOLOGY, Issue 1 2007D. E. Shoup Growth of sympatric populations of three important sport fish species: bluegill Lepomis macrochirus, largemouth bass Micropterus salmoides and channel catfish Ictalurus punctatus, in 14 Illinois reservoirs was assessed in an attempt to relate size-specific growth to environmental conditions. Multiple regression relationships for most species and size classes explained a large percentage of the variation in growth. Growth of small bluegill (50 mm total length, LT) showed a strong negative relationship with bluegill catch per unit effort (cpue), per cent littoral area and pH. Large bluegill (150 mm LT) growth was negatively related to Daphnia spp. and benthic macroinvertebrate abundance and lake volume, and positively related to bluegill cpue. Growth of small (100 mm LT) and large (250 mm LT) largemouth bass was not well explained by any of the measured variables. Growth of both small (300 mm LT) and large (450 mm LT) channel catfish was strongly positively related to forage fishes and ichthyoplankton abundance, and per cent littoral area while negatively related to benthic macroinvertebrates. By identifying environmental conditions associated with increased growth rates, these models provide direction for managing fish populations and suggest testable hypotheses for future study of the complex interactions between environmental conditions and growth. [source] Ontogeny and sexual dimorphism in booted macaques (Macaca ochreata)JOURNAL OF ZOOLOGY, Issue 1 2005Michael A. Schillaci Abstract Ontogeny and sexual dimorphism have been important topics of investigation among researchers interested in the life history and ecology of non-human primates. It has been suggested that sex differences in the duration of growth are primarily, but not entirely, responsible for the sexual dimorphism observed in primate species with multimale,multifemale social structure, such as that seen in macaque monkeys (subfamily Cercopithecinae). Sexual dimorphism and growth was investigated in a wild population of booted macaques Macaca ochreata from Sulawesi, Indonesia. The results of our investigation suggest that the observed dimorphism in this population is primarily a product of greatly increased growth rates in dentally mature young adult males, in addition to prolonged male growth. This pattern of male growth may be an adaptive response to reduce the risk of adult male aggression before obligatory male emigration, and to facilitate competition for females soon after immigration into a new social group. [source] Vestibular Schwannoma Quantitative Polymerase Chain Reaction Expression of Estrogen and Progesterone Receptors,THE LARYNGOSCOPE, Issue 8 2008Andrew K. Patel MD Abstract Objectives/Hypothesis: Determine the role of estrogen receptor (ER) and progesterone receptor (PR) expression in sporadic and neurofibromatosis 2 (NF2)-related vestibular schwannomas (VS). Growth and proliferation signaling in human VS tumorigenesis may play a key role in molecular therapeutic targeting. VS carry mutations of the NF2 gene encoding the tumor suppressor, merlin, which interacts with ErbB2 in Schwann cells, implicating ErbB receptors in VS tumorigenesis. ErbB receptor family members are overexpressed or constitutively activated in many human tumors, and are effective therapeutic targets in some human cancers. VS occur more frequently in women and are larger, more vascular, and demonstrate increased growth rates during pregnancy. ER and PR may play a role in ErbB pathway activation and VS progression. Study Design: Quantitative real-time polymerase chain reaction (qRT-PCR) for ER and PR messenger RNA was performed using greater auricular and vestibular nerve controls (n = 8), sporadic VS (n = 23), and NF2-related VS (n = 16) tissues. Methods: The qRT-PCR data were normalized with standardization to a single constitutively expressed control gene, human cyclophylin. Results: Reverse transcription of messenger RNA from control and tumor specimens followed by RT Q-PCR demonstrated differences in ER and PR gene expression between sporadic and NF2-related VS. Conclusions: ER and PR expression in VS might have implications for development of a VS-specific drug delivery system using antihormone and ErbB pathway small molecule inhibitors, due to crosstalk between these receptors. These signals may be critical for re-establishing ErbB-mediated cell density dependent growth inhibition. [source] The impacts of rising CO2 concentrations on Australian terrestrial species and ecosystemsAUSTRAL ECOLOGY, Issue 6 2010MARK J. HOVENDEN Abstract The increasing atmospheric concentration of carbon dioxide ([CO2]) contributes to global warming and the accompanying shifts in climate. However, [CO2] itself has the potential to impact on Australia's terrestrial biodiversity, due to its importance in the photosynthetic process, which underlies all terrestrial food webs. Here, we review our knowledge regarding the impacts of elevated [CO2] on native terrestrial species and ecosystems, and suggest key areas in which we have little information on this topic. Experimental information exists for 70 (or less than 0.05%) of Australia's native terrestrial plant and animal species. Of these, 68 are vascular plants. The growth of Australian woody species is more reliably increased by elevated [CO2] than it is in grasses. At the species level, the most overwhelming responses to increased [CO2] are a reduction in plant nitrogen concentration and an increase in the production of secondary metabolites. This is of particular concern for Australia's unique herbivorous and granivorous marsupials, for which no information is available. While many plant species also displayed increased growth rates at higher [CO2], this was far from universal, indicating that changes in community structure and function are likely, leading to alterations of habitat quality. Future research should be directed to key knowledge gaps including the relationship between [CO2], fire frequency and fire tolerance and the impacts of increasing [CO2] for Australia's iconic browsing mammals. We also know virtually nothing of the impacts of the increasing [CO2] on Australia's unique shrublands and semi-arid/arid rangelands. In conclusion, there is sufficient information available to be certain that the increasing [CO2] will affect Australia's native biodiversity. However, the information required to formulate predictions concerning the long-term future of almost all organisms is far in excess of that currently available. [source] Biotechnology in Aquaculture: Transgenics and PolyploidyCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 1 2007Rosalee S. Rasmussen ABSTRACT:, Although capture fisheries have experienced slow to stagnant growth in recent years, the world population has been increasing, with subsequent rises in demands for marine-based foods. One possibility for alleviating potential food shortages and price increases is through aquaculture, which has experienced rapid worldwide expansion. A major focus of research in the aquaculture industry is on the use of biotechnology to increase food availability and reduce production costs, specifically through the manipulation of the genes and chromosomes of cultivated species. Examples include transgenic fish with properties such as increased growth rates, feed conversion efficiency, disease resistance, cold tolerance, and improved metabolism of land-based plants. However, use of transgenic organisms in aquaculture is a very controversial topic due to a number of environmental and human health concerns such as escapement and introduction of genetically modified organisms into the food chain. In response, some transgenic research has also been focused on inducing sterility to reduce the risk of transgenic organisms breeding with wild species. A method of chromosome manipulation, referred to as polyploidy, provides the option of creating sterile organisms, some of which also exhibit increased growth rates. This review paper will discuss recent advances in biotechnology research, specifically in regards to the manipulation of genes and chromosomes, for enhanced cultivation of fish and invertebrates. Major environmental and human health concerns will also be addressed. [source] | ||||||||||||||||