964 resultados para Axillary Bud Outgrowth
Resumo:
The Australian elapid snakes are amongst the most venomous snakes in the world, but much less is known about the overall venom composition in comparison to Asian and American snakes. We have used a combined approach of cDNA cloning and 2-DE with MS to identify nerve growth factor (NGF) in venoms of the Australian elapid snakes and demonstrate its neurite outgrowth activity While a single 730 nucleotide ORF, coding for a 243 amino acid precursor protein was detected in all snakes, use of 2-DE identified NGF proteins with considerable variation in molecular size within and between the different snakes. The variation in size can be explained at least in part by Winked glycosylation. it is possible that these modifications alter the stability, is necessary to activity and other characteristics of the snake NGFs. Further characterisation delineate the function of the individual NGF isoforms.
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Neonatal X-irradiation of central nervous system (CNS) tissue markedly reduces the glial population in the irradiated area. Previous in vivo studies have demonstrated regenerative success of adult dorsal root ganglion (DRG) neurons into the neonatally-irradiated spinal cord. The present study was undertaken to determine whether these results could be replicated in an in vitro environment. The lumbosacral spinal cord of anaesthetised Wistar rat pups, aged between 1 and 5 days, was subjected to a single dose (40 Gray) of X-irradiation. A sham-irradiated group acted as controls. Rats were allowed to reach adulthood before being killed. Their lumbosacral spinal cords were dissected out and processed for sectioning in a cryostat. Cryosections (10 mum-thick) of the spinal cord tissue were picked up on sterile glass coverslips and used as substrates for culturing dissociated adult DRG neurons. After an appropriate incubation period, cultures were fixed in 2% paraformaldehyde and immunolabelled to visualise both the spinal cord substrate using anti-glial fibrillary acidic protein (GFAP) and the growing DRG neurons using anti-growth associated protein (GAP-43). Successful growth of DRG neurites was observed on irradiated, but not on non-irradiated, sections of spinal cord. Thus, neonatal X-irradiation of spinal cord tissue appears to alter its environment such that it can later support, rather than inhibit, axonal regeneration. It is suggested that this alteration may be due, at least in part, to depletion in the number of and/or a change in the characteristics of the glial cells. (C) 2000 ISDN. Published by Elsevier Science Ltd. All rights reserved.
QUALIDADE DE VIDA E ESTRATÉGIAS DE ENFRENTAMENTO DE MULHERES COM E SEM LINFEDEMA APÓS CÂNCER DE MAMA
Resumo:
O linfedema no membro superior é uma complicação inerente ao tratamento de câncer de mama. Caracterizado pelo aumento do volume do membro, leva às limitações físicas e funcionais, e impacto negativo no âmbito psicológico e social. O objetivo deste estudo foi investigar a qualidade de vida e seus domínios, as estratégias de enfrentamento frente ao câncer de mama, e a correlação entre essas variáveis. Este estudo foi realizado em um centro de saúde dedicado às mulheres, por quatro meses. Os instrumentos de avaliação foram: questionário de caracterização geral e específico do câncer de mama, perimetria dos membros superiores; questionários de qualidade de vida da Organização Européia de Pesquisa e Tratamento do Câncer, EORTC QLQ-30 e BR-23; e Inventário de Estratégias de Coping. Foram entrevistadas 82 mulheres, idade média de 57,4 anos (DV12,3), submetidas a tratamento cirúrgico de mama unilateral e esvaziamento axilar, sem metástase. O linfedema apresentou-se em 39,03% (32) e parece não interferir muito na qualidade de vida das mulheres pós-câncer de mama, sendo a função social a mais prejudicada. Sintomas relacionados à quimioterapia e a mama incomodam as mulheres de ambos grupos, porém os sintomas relacionados aos braços foram estatisticamente maiores nas portadoras de linfedema. As estratégias mais utilizadas pelas entrevistadas para enfrentar o câncer foram a reavaliação, resolução de problemas, fuga, suporte social e autocontrole, somente o autocontrole foi estatisticamente maior nas mulheres com linfedema. As estratégias de resolução de problemas, autocontrole e baixo suporte social podem ter colaborado para o desencadeamento do linfedema. Conclui-se que o uso de estratégias ativas e positivas para enfrentar o câncer de mama parece resultar na boa adaptação psicossocial
Resumo:
This thesis describes research into business user involvement in the information systems application building process. The main interest of this research is in establishing and testing techniques to quantify the relationships between identified success factors and the outcome effectiveness of 'business user development' (BUD). The availability of a mechanism to measure the levels of the success factors, and quantifiably relate them to outcome effectiveness, is important in that it provides an organisation with the capability to predict and monitor effects on BUD outcome effectiveness. This is particularly important in an era where BUD levels have risen dramatically, user centred information systems development benefits are recognised as significant, and awareness of the risks of uncontrolled BUD activity is becoming more widespread. This research targets the measurement and prediction of BUD success factors and implementation effectiveness for particular business users. A questionnaire instrument and analysis technique has been tested and developed which constitutes a tool for predicting and monitoring BUD outcome effectiveness, and is based on the BUDES (Business User Development Effectiveness and Scope) research model - which is introduced and described in this thesis. The questionnaire instrument is designed for completion by 'business users' - the target community being more explicitly defined as 'people who primarily have a business role within an organisation'. The instrument, named BUD ESP (Business User Development Effectiveness and Scope Predictor), can readily be used with survey participants, and has been shown to give meaningful and representative results.
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Cell surface properties of the basidiomycete yeast Cryptococcus neoformans were investigated with a combination of novel and well proven approaches. Non-specific cell adhesion forces, as well as exposed carbohydrate and protein moieties potentially associated with specific cellular interaction, were analysed. Experimentation and analysis employed cryptococcal cells of different strains, capsular status and culture age. Investigation of cellular charge by particulate microelectrophoresis revealed encapsulated yeast forms of C. neoformans manifest a distinctive negative charge regardless of the age of cells involved; in turn, the neutral charge of acapsulate yeasts confirmed that the polysaccharide capsule, and not the cell wall, was responsible for this occurrence. Hydrophobicity was measured by MATH and HICH techniques, as well as by the attachment of polystyrene microspheres. All three techniques, where applicable, found C. neoformans yeast to be consistently hydrophilic; this state varied little regardless of strain and culture age. Cell surface carbohydrates and protein were investigated with novel fluorescent tagging protocols, flow cytometry and confocal microscopy. Cell surface carbohydrate was identified by controlled oxidation in association with biotin hydrazide and fluorescein-streptavidin tagging. Marked amounts of carbohydrate were measured and observed on the cell wall surface of cryptococcal yeasts. Furthermore, tagging of carbohydrates with selective fluorescent lectins supported the identification, measurement and observation of substantial amounts of mannose, glucose and N-acetyl-glucosamine. Cryptococcal cell surface protein was identified using sulfo-NHS-biotin with fluorescein-streptavidin, and then readily quantified by flow cytometry. Confocal imaging of surface exposed carbohydrate and protein revealed common localised areas of vivid fluorescence associated with buds, bud scars and nascent daughter cells. Carbohydrate and protein fluorescence often varied between strains, culture age and capsule status of cells examined. Finally, extension of protein tagging techniques resulted in the isolation and extraction of two biotinylated proteins from the yeast cell wall surface of an acapsulate strain of C.neoformans.
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Background - Few epidemiological studies have prospectively investigated preoperative and surgical risk factors for acute postoperative pain after surgery for breast cancer. We investigated demographic, psychological, pain-related and surgical risk factors in women undergoing resectional surgery for breast cancer. Methods - Primary outcomes were pain severity, at rest (PAR) and movement-evoked pain (MEP), in the first postoperative week. Results - In 338 women undergoing surgery, those with chronic preoperative pain were three times more likely to report moderate to severe MEP after breast cancer surgery (OR 3.18, 95% CI 1.45–6.99). Increased psychological ‘robustness’, a composite variable representing positive affect and dispositional optimism, was associated with lower intensity acute postoperative PAR (OR 0.63, 95% CI 0.48–0.82) and MEP (OR 0.71, 95% CI 0.54–0.93). Sentinel lymph node biopsy (SLNB) and intraoperative nerve division were associated with reduced postoperative pain. No relationship was found between preoperative neuropathic pain and acute pain outcomes; altered sensations and numbness postoperatively were more common after axillary sample or clearance compared with SLNB. Conclusion - Chronic preoperative pain, axillary surgery and psychological robustness significantly predicted acute pain outcomes after surgery for breast cancer. Preoperative identification and targeted intervention of subgroups at risk could enhance the recovery trajectory in cancer survivors.
Resumo:
An international round robin study of the viscosity measurements and aging of fast pyrolysis bio-oil has been undertaken recently, and this work is an outgrowth from that effort. Two bio-oil samples were distributed to two laboratories for accelerated aging tests and to three laboratories of long-term aging studies. The accelerated aging test was defined as the change in viscosity of a sealed sample of bio-oil held for 24 h at 80 °C. The test was repeated 10 times over consecutive days to determine the intra-laboratory repeatability of the method. Other bio-oil samples were placed in storage at three temperatures, 21, 5, and -17 °C, for a period of up to 1 year to evaluate the change in viscosity. The variation in the results of the accelerated aging test was shown to be low within a given laboratory. The long-term aging studies showed that storage of a filtered bio-oil under refrigeration can minimize the amount of change in viscosity. The accelerated aging test gave a measure of change similar to that of 6-12 months of storage at room temperature for a filtered bio-oil. Filtration of solids was identified as a key contributor to improving the stability of the bio-oil as expressed by the viscosity based on results of the accelerated aging tests as well as long-term aging studies. Only the filtered bio-oil consistently gave useful results in the accelerated aging and long-term aging studies. The inconsistency suggests that better protocols need to be developed for sampling bio-oils. These results can be helpful in setting standards for use of bio-oil, which is just coming into the marketplace. © 2012 American Chemical Society.
Resumo:
Study Design. Coculture assays of the migration and interaction of human intervertebral disc cells and chick sensory nerves on alternate substrata of collagen and aggrecan. Objective. To examine the effects of aggrecan on disc cell migration, how disc cells and sensory nerves interact, and whether disc cells affect previously reported inhibitory effects of aggrecan on sensory nerve growth. Summary of Background Data. Human intervertebral disc aggrecan is inhibitory to sensory nerve growth in vitro, suggesting that a loss of aggrecan from the disc may have a role in the increased innervation seen in disc degeneration. Endothelial cells that appear to co-migrate with nerves into degenerated intervertebral disc express neurotrophic factors, but the effects of disc cells on nerve growth are not known. Methods. Human disc cells were seeded onto tissue culture plates that had been coated with type I collagen and human intervertebral disc aggrecan. Explants of chick dorsal root ganglions (DRGs) were subsequently added to the plates and sensory neurite outgrowth stimulated by the addition of nerve growth factor. Time-lapse video and fluorescence microscopy were used to examine the migration and interaction of the disc cells and sensory neurites, in the context of the different matrix substrata. The effects of disc cell conditioned medium on nerve growth were also examined. Results. Disc cells spread and migrated on collagen until they encountered the aggrecan substrata, where some cells, but not all, were repelled. In coculture, DRG neurites extended onto the collagen/disc cells until they encountered the aggrecan, where, like the disc cells, many were repelled. However, in the presence of disc cells, some neurites were able to cross onto this normally inhibitory substratum. The number of neurite crossings onto aggrecan correlated significantly with the number of disc cells present on the aggrecan. In control experiments using DRG alone, all extending neurites were repelled at the collagen/aggrecan border. Conditioned medium from disc cell cultures stimulated DRG neurite outgrowth on collagen but did not increase neurite crossing onto aggrecan substrata. Conclusions. Human disc cells migrate across aggrecan substrata that are repellent to sensory DRG neurites. Disc cells synthesize neurotrophic factors in vitro that promote neurite outgrowth. Furthermore, the presence of disc cells in coculture with DRG partially abrogates the inhibitory effects of aggrecan on nerve growth. These findings have important implications for the regulation of nerve growth into the intervertebral disc, but whether disc cells promote nerve growth in vivo remains to be determined.
Resumo:
The vase-life of Alstroemeria (cv. Rebecca) flowers is terminated when the tepals abscise. Abscission was accelerated by both chloroethylphosphonic acid (CEPA) and 1-aminocyclopropane-1-carboxylic acid (ACC). Petals abscised 24 h earlier compared with controls, when isolated cymes were placed in 340 nM CEPA, and earlier still when higher concentrations were used. This suggests that flowers of this Alstroemeria cultivar are very ethylene sensitive. Treatment with silver thiosulphate (STS) overcame the effects of exposure to CEPA and delayed perianth abscission of untreated isolated flowers by 3-4 days. The inclusion of 1% sucrose in the vase solution also extended longevity but not by as much as STS treatment; combined STS and sucrose treatments did not increase longevity beyond that of either treatment alone. However, removal of the young buds from the axil of the first flower was the most effective treatment to extend vase-life and encouraged the growth and development of the remaining flower. Flowers on cut inflorescences from which young axillary buds were trimmed more than doubled in fresh weight 6 days after flower opening compared with an increase of only 70-80% in those untreated or treated with STS and/or sucrose. Growth was less in isolated cymes but followed a similar pattern. The effect of STS and/or sucrose treatment was synergistic with the trimming treatment and thus the vase-life of trimmed, STS and sucrose-treated flowers was over 7 days longer than that for untreated controls. © 2003 Elsevier B.V. All rights reserved.
Resumo:
Retinoic acid (RA) signaling is important to normal development. However, the function of the different RA receptors (RARs)-RARα, RARβ, and RARγ-is as yet unclear. We have used wild-type and transgenic zebrafish to examine the role of RARγ. Treatment of zebrafish embryos with an RARγ-specific agonist reduced somite formation and axial length, which was associated with a loss of hoxb13a expression and less-clear alterations in hoxc11a or myoD expression. Treatment with the RARγ agonist also disrupted formation of tissues arising from cranial neural crest, including cranial bones and anterior neural ganglia. There was a loss of Sox 9-immunopositive neural crest stem/progenitor cells in the same anterior regions. Pectoral fin outgrowth was blocked by RARγ agonist treatment. However, there was no loss of Tbx-5-immunopositive lateral plate mesodermal stem/progenitor cells and the block was reversed by agonist washout or by cotreatment with an RARγ antagonist. Regeneration of the caudal fin was also blocked by RARγ agonist treatment, which was associated with a loss of canonical Wnt signaling. This regenerative response was restored by agonist washout or cotreatment with the RARγ antagonist. These findings suggest that RARγ plays an essential role in maintaining stem/progenitor cells during embryonic development and tissue regeneration when the receptor is in its nonligated state.
Resumo:
Human mesenchymal stem cell (hMSC) therapies are currently progressing through clinical development, driving the need for consistent, and cost effective manufacturing processes to meet the lot-sizes required for commercial production. The use of animal-derived serum is common in hMSC culture but has many drawbacks such as limited supply, lot-to-lot variability, increased regulatory burden, possibility of pathogen transmission, and reduced scope for process optimization. These constraints may impact the development of a consistent large-scale process and therefore must be addressed. The aim of this work was therefore to run a pilot study in the systematic development of serum-free hMSC manufacturing process. Human bone-marrow derived hMSCs were expanded on fibronectin-coated, non-porous plastic microcarriers in 100mL stirred spinner flasks at a density of 3×105cells.mL-1 in serum-free medium. The hMSCs were successfully harvested by our recently-developed technique using animal-free enzymatic cell detachment accompanied by agitation followed by filtration to separate the hMSCs from microcarriers, with a post-harvest viability of 99.63±0.03%. The hMSCs were found to be in accordance with the ISCT characterization criteria and maintained hMSC outgrowth and colony-forming potential. The hMSCs were held in suspension post-harvest to simulate a typical pooling time for a scaled expansion process and cryopreserved in a serum-free vehicle solution using a controlled-rate freezing process. Post-thaw viability was 75.8±1.4% with a similar 3h attachment efficiency also observed, indicating successful hMSC recovery, and attachment. This approach therefore demonstrates that once an hMSC line and appropriate medium have been selected for production, multiple unit operations can be integrated to generate an animal component-free hMSC production process from expansion through to cryopreservation.
Resumo:
Retinoic acid (RA) is thought to signal through retinoic acid receptors (RARs), i.e. RARα, β, and γ to play important roles in embryonic development and tissue regeneration. In this thesis, the zebrafish (Danio rario) was used as a vertebrate model organism to examine the role of RARγ. Treatment of zebrafish embryos with a RARγ specific agonist reduced the axial length of developing embryos, associated with reduced somite number and loss of hoxb13a expression. There were no clear alterations in hoxc11a or myoD expression. Treatment with the RARγ agonist disrupted the formation of anterior structures of the head, the cranial bones and the anterior lateral line ganglia, associated with a loss of sox9 immunopositive cells in the same regions. Pectoral fin outgrowth was blocked by treatment with the RARγ agonist; however, this was not associated with loss of tbx5a immunopositive lateral plate cells and was reversed by wash out of the RARγ agonist or co-treatment with a RARγ antagonist. Regeneration of the transected caudal fin was also blocked by RARγ agonist treatment and restored by agonist washout or antagonist co-treatment; this phenotype was associated with a localised reduction in canonical Wnt signalling. Conversely, elevated canonical Wnt signalling after RARγ treatment was seen in other tissues, including ectopically in the notochord. Furthermore, some phenotypes seen in the RARγ treated embryos were present in mutant zebrafish embryos in which canonical Wnt signalling was constitutively increased. These data suggest that RARγ plays an essential role in maintaining neural crest and mesodermal stem/progenitor cells during normal embryonic development and tissue regeneration when the receptor is in its non-ligated state. In addition, this work has provided evidence that the activation status of RARγ may regulate hoxb13a gene expression and canonical Wnt signalling. Further research is required to confirm such novel regulatory roles.
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Small potted trees of Spondias purpurea were monitored to determine the costs and controls of flowering and fruiting. The effect of photoperiod, extremes in moisture and temperature, and defoliation were examined. The carbon exchange rates of the leaves, shoots and fruits were determined. Light response curves and diurnal levels were also investigated. $\sp{13}$Carbon labeling was used to determine which plant parts are carbon sinks. Photoperiod induces dormancy and bud activity. Extremes in soil moisture and temperature induce leaf fall. Flowers, fruits, and roots are carbon sinks. The results were used to develop a phenological model with latitude, soil moisture, and air temperature as variables. ^
Resumo:
Nerve development, which includes axon outgrowth and guidance, is regulated by many protein families, including receptor protein tyrosine phosphatases (RPTP's).Protein tyrosine phosphatase receptor type 0 (PTPRO) is a type III RPTP that is important for axon growth and guidance, as observed in chicks and flies. In order to examine the effects ofPTPRO on mammalian development, standard behavioral tests were used to compare mice lacking the gene for PTPRO (ROKO mice) to wild-type (WT) mice. The ROKO mice showed a significant delay in reacting to a thermal noxious stimulus, hotplate analgesia, when compared to the WT mice suggesting deficient nociceptive function. In a rotarod test for proprioceptive function the ROKO mice exhibited a significant decrease in the amount of time spent on the rotating rod than did the WT mice. Additional proprioception tests were performed including the climb, step reflex, beam, and mesh walk tests. In the climb and step (place) test, the ROKO group had a significantly lower accuracy in performing the tests than did the WT mice. Thus, mice lacking the PTPRO gene showed behavioral deficiencies that reflect impairment in sensory function, specifically for nociception and proprioception.
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Receptor-tyrosine kinases (RTKs) are membrane bound receptors characterized by their intrinsic kinase activity. RTK activities play an essential role in several human diseases, including cancer, diabetes and neurodegenerative diseases. RTK activities have been regulated by the expression or silencing of several genes as well as by the utilization of small molecules. Ras Interference 1 (Rin1) is a multifunctional protein that becomes associated with activated RTKs upon ligand stimulation. Rin1 plays a key role in receptor internalization and in signal transduction via activation of Rab5 and association with active form of Ras. This study has two main objectives: (1) It determines the role of Rin1 in the regulation of several RTKs focusing on insulin receptor. This was accomplished by studying the Rin1-insulin receptor interaction using a variety of biochemical and morphological assays. This study shows a novel interaction between the insulin receptor and Rin1 through the Vps9 domain. Two more RTKs (epidermal growth factor receptor and nerve growth factor receptor) also interacted with the SH2 domain of Rin1. The effect of the Rin1-RTK interaction on the activation of both Rab5 and Ras was also studied during receptor internalization and intracellular signaling. Finally, the role of Rin1 was examined in two differentiation processes (adipogenesis and neurogenesis). Rin1 showed a strong inhibitory effect on 3T3-L1 preadipocyte differentiation but it seems to show a modest effect in PC12 neurite outgrowth. These data indicate a selective function and specific interaction of Rin1 toward RTKs. (2) It examines the role of the small molecule Dehydroleucodine (DhL) on several key signaling molecules during adipogenesis. This was accomplished by studying the differentiation of 3T3-L1 preadipocytes exposed to different concentrations of DhL in different days of the adipocyte formation process. The results indicate that DhL selectively blocked adipocyte formation, as well as the expression of PPARγ, and C/EBP&agr;. However, DhL treatment did not affect Rin1 or Rab5 expression and their activities. Taken together, the data indicate a potential molecular mechanism by which proteins or small molecules regulate selective and specific RTK intracellular membrane trafficking and signaling during cell growth and differentiation in normal and pathological conditions.