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Search Results: 1 - 10 of 71379 matches for " Maria Fitzgerald "
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Acute Pain and a Motivational Pathway in Adult Rats: Influence of Early Life Pain Experience
Lucie A. Low, Maria Fitzgerald
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0034316
Abstract: Background The importance of neonatal experience upon behaviour in later life is increasingly recognised. The overlap between pain and reward pathways led us to hypothesise that neonatal pain experience influences reward-related pathways and behaviours in adulthood. Methodology/Principal Findings Rat pups received repeat plantar skin incisions (neonatal IN) or control procedures (neonatal anesthesia only, AN) at postnatal days (P)3, 10 and 17. When adult, rats with neonatal ‘pain history’ showed greater sensory sensitivity than control rats following acute plantar skin incision. Motivational behaviour in the two groups of rats was tested in a novelty-induced hypophagia (NIH) paradigm. The sensitivity of this paradigm to pain-induced changes in motivational behaviour was shown by significant increases in the time spent in the central zone of the arena (43.7±5.9% vs. 22.5±6.7%, p<0.05), close to centrally placed food treats, and decreased number of rears (9.5±1.4 vs. 19.2±2.3, p<0.001) in rats with acute plantar skin incision compared to naive, uninjured animals. Rats with a neonatal ‘pain history’ showed the same pain-induced behaviour in the novelty-induced hypophagia paradigm as controls. However, differences were observed in reward-related neural activity between the two groups. Two hours after behavioural testing, brains were harvested and neuronal activity mapped using c-Fos expression in lateral hypothalamic orexin neurons, part of a specific reward seeking pathway. Pain-induced activity in orexin neurons of control rats (18.4±2.8%) was the same as in uninjured naive animals (15.5±2.6%), but in those rats with a ‘pain history’, orexinergic activity was significantly increased (27.2±4.1%, p<0.01). Furthermore the extent of orexin neuron activation in individual rats with a ‘pain history’ was highly correlated with their motivational behaviour (r = ?0.86, p = 0.01). Conclusions/Significance These results show that acute pain alters motivational behaviour and that neonatal pain experience causes long-term changes in brain motivational orexinergic pathways, known to modulate mesolimbic dopaminergic reward circuitry.
How Well Do Clinical Pain Assessment Tools Reflect Pain in Infants?
Rebeccah Slater ,Anne Cantarella,Linda Franck,Judith Meek,Maria Fitzgerald
PLOS Medicine , 2008, DOI: 10.1371/journal.pmed.0050129
Abstract: Background Pain in infancy is poorly understood, and medical staff often have difficulty assessing whether an infant is in pain. Current pain assessment tools rely on behavioural and physiological measures, such as change in facial expression, which may not accurately reflect pain experience. Our ability to measure cortical pain responses in young infants gives us the first opportunity to evaluate pain assessment tools with respect to the sensory input and establish whether the resultant pain scores reflect cortical pain processing. Methods and Findings Cortical haemodynamic activity was measured in infants, aged 25–43 wk postmenstrual, using near-infrared spectroscopy following a clinically required heel lance and compared to the magnitude of the premature infant pain profile (PIPP) score in the same infant to the same stimulus (n = 12, 33 test occasions). Overall, there was good correlation between the PIPP score and the level of cortical activity (regression coefficient = 0.72, 95% confidence interval [CI] limits 0.32–1.11, p = 0.001; correlation coefficient = 0.57). Of the different PIPP components, facial expression correlated best with cortical activity (regression coefficient = 1.26, 95% CI limits 0.84–1.67, p < 0.0001; correlation coefficient = 0.74) (n = 12, 33 test occasions). Cortical pain responses were still recorded in some infants who did not display a change in facial expression. Conclusions While painful stimulation generally evokes parallel cortical and behavioural responses in infants, pain may be processed at the cortical level without producing detectable behavioural changes. As a result, an infant with a low pain score based on behavioural assessment tools alone may not be pain free.
The emergence of adolescent onset pain hypersensitivity following neonatal nerve injury
David Vega-Avelaira, Rebecca McKelvey, Gareth Hathway, Maria Fitzgerald
Molecular Pain , 2012, DOI: 10.1186/1744-8069-8-30
Abstract: Spared nerve injury (SNI) or sham surgery was performed on 10 day old (P10) rat pups and mechanical nociceptive reflex thresholds were analysed 3, 7, 14, 21, 28, 38 and 44 days post surgery. While mechanical thresholds on the ipsilateral side are not significantly different from controls for the first 2–3 weeks post P10 surgery, after that time period, beginning at 21 days post surgery (P31), the SNI group developed following early life nerve injury significant hypersensitivity compared to the other groups. Ipsilateral mechanical nociceptive threshold was 2-fold below that of the contralateral and sham thresholds at 21 days post surgery (SNI-ipsilateral 28 (±5) g control groups 69 (±9) g, p < 0.001, 3-way ANOVA, n = 6 per group). Importantly, no effect was observed on thermal thresholds. This hypersensivity was accompanied by macrophage, microglial and astrocyte activation in the DRG and dorsal horn, but no significant change in dorsal horn p38 or JNK expression. Preemptive minocycline (daily 40 mg/kg, s.c) did not prevent the effect. Ketamine (20 mg/kg, s.c), on the other hand, produced a dose-dependent reversal of mechanical nociceptive thresholds ipsilateral to the nerve injury such that thresholds return to control levels at the highest doses of 20 mg/Kg.We report a novel consequence of early life nerve injury whereby mechanical hypersensitivity only emerges later in life. This delayed adolescent onset in mechanical pain thresholds is accompanied by neuroimmune activation and NMDA dependent central sensitization of spinal nociceptive circuits. This delayed onset in mechanical pain sensitivity may provide clues to understand the long term effects of early injury such as late onset phantom pain and the emergence of complex adolescent chronic pain syndromes.
Differential regulation of immune responses and macrophage/neuron interactions in the dorsal root ganglion in young and adult rats following nerve injury
David Vega-Avelaira, Sandrine M Géranton, Maria Fitzgerald
Molecular Pain , 2009, DOI: 10.1186/1744-8069-5-70
Abstract: We have performed a microarray analysis of the rat L4/L5 dorsal root ganglia (DRG), 7 days post spared nerve injury, a model of neuropathic pain. Genes that are regulated in adult rats displaying neuropathic behaviour were compared to those regulated in young rats (10 days old) that did not show the same neuropathic behaviour. The results show a set of genes, differentially regulated in the adult DRG, that are principally involved in immune system modulation. A functional consequence of this different immune response to injury is that resident macrophages cluster around the large A sensory neuron bodies in the adult DRG seven days post injury, whereas the macrophages in young DRG remain scattered evenly throughout the ganglion, as in controls.The results show, for the first time, a major difference in the neuroimmune response to nerve injury in the dorsal root ganglion of young and adult rats. Differential analysis reveals a new set of immune related genes in the ganglia, that are differentially regulated in adult neuropathic pain, and that are consistent with the selective activation of macrophages around adult, but not young large A sensory neurons post injury. These differences may contribute to the reduced incidence of neuropathic pain in infants.Physiological pain is an acute experience that results from the activation of peripheral nociceptors in injured and inflamed tissues and which normally passes when the stimulus ceases. In contrast, neuropathic pain is an apparently spontaneous experience triggered by abnormal physiology of the peripheral or central nervous system, which evolves with time. Neuropathic pain arising from peripheral nerve injury is characterized by a combination of spontaneous pain, hyperalgesia and allodynia and as it is poorly relieved by conventional analgesics, it is a significant clinical problem [1]. Neuropathic pain is less common in children than in adults. Although it has been reported in very young paediatric patients [2], there i
Exploring the Association between Adult Attachment Styles in Romantic Relationships, Perceptions of Parents from Childhood and Relationship Satisfaction  [PDF]
Gwen Gleeson, Amanda Fitzgerald
Health (Health) , 2014, DOI: 10.4236/health.2014.613196
Abstract: Little research has examined how attachment styles in childhood are related to current romantic relationship experiences. The aim of this study was to explore the association between perceptions of childhood experiences with parents, attachment styles in romantic relationships, and relationship satisfaction in a sample of young adults. The sample consisted of 227 participants, 153 of which were university students and the remaining 69 were members of the general population. Of these, 177 (78%) were female and 50 (22%) were male, with an age range of 18 - 39. Participants completed a battery of self-report measures assessing their attachment style in romantic relationships, satisfaction in their current romantic relationship, and an adjective checklist describing their parents and their parent’s relationship with each other. The majority of males had an avoidant-fearful style, while females tended to have an avoidant-fearful or secure style. Findings were that participants’ descriptions of their mother, father, and parental relationship were associated with their attachment style. In terms of a current romantic relationship, those with a secure attachment style were much more likely to be in a relationship whereas those with an avoidant-fearful style were not. Secure participants were more satisfied in their relationships than the insecure styles of attachment. Finally, chi-square tests revealed that there was no association between gender and attachment style. Results were discussed in terms of methodological limitations such as the use of self-report measures; theoretical weaknesses for example the variability in the approaches used in attachment research; and future research, which included the use of longitudinal studies which may offer insight into how early parenting behaviours act as predictors of later relationship functioning.
Increasing Road Traffic Throughput through Dynamic Traffic Accident Risk Mitigation  [PDF]
Emma Fitzgerald, Bjorn Landfeldt
Journal of Transportation Technologies (JTTs) , 2015, DOI: 10.4236/jtts.2015.54021
Abstract: The introduction of vehicular ad-hoc networks (VANETs) leads to the possibility to re-evaluate many traditional functions and views of road traffic networks. The ability for vehicles and infrastructure to communicate and collaborate will enable many novel solutions for problems as diverse as collision avoidance and traffic management with the view of reducing traffic congestion, increasing the effectiveness of logistics systems etc. In this paper we introduce a novel framework that utilises VANET information to share information about risk factors among road occupants and infrastructure. We introduce the concept of risk limits as a means of traffic accident risk mitigation, whereby vehicles need to adjust their behaviour to maintain a given level of risk. We discuss determination of risk values and detail this process using the NSW traffic accident database. We show how the effects on risk of particular vehicular behaviours such as speed and headway can be calculated and use these results to modify vehicle behaviour in real time to maintain a predefined risk limit. Experiments are carried out using the Paramics Microsimulator. Our results show that it is possible to reduce the accident rate among vehicles while at the same time increasing road network throughput by exploiting the variation in risk between vehicles.
Psoriatic arthritis synovial histopathology: commentary on the article by Kruithof and colleagues
Oliver FitzGerald
Arthritis Research & Therapy , 2005, DOI: 10.1186/ar1747
Abstract: The excellent article by Kruithof and colleagues stimulates many questions while carefully dissecting differentiating features in synovial histopathology that characterize rheumatoid arthritis (RA) and spondyloarthropathy (SpA), in particular psoriatic arthritis (PsA) [1]. Using a semi-quantitative scoring system, the authors identified a number of features characteristic of RA synovium, including the lining layer thickness, CD83+ dendritic cells, positive staining for intracellular citrullinated proteins (44%) and positive staining for MHC/HC gp-39 peptide complexes (46%). In the SpA group as a whole and in the PsA subgroup alone, increased vascularity and neutrophil numbers distinguished from RA. CD163+ macrophages were also increased in SpA. Interestingly, no significant differences were seen between oligoarticular PsA versus polyarticular PsA. The authors conclude that the synovitis in PsA, both oligoarticular and polyarticular, resembles SpA more than RA.These observations have a number of important implications. First, although this has been disputed [2], it may be possible to diagnose RA based on the positive staining as already stated. In Kruithof and colleagues' study, positive staining for intracellular citrullinated proteins and positive staining for MHC/HC gp-39 peptide complexes were seen only in RA, although each were present in <50%. Second, the synovitis in PsA shows similar features to other SpA patients, both ankylosing spondylitis and undifferentiated SpA.Previous studies have compared PsA with RA [3], although Kruithof and colleagues' study is the first to include other SpA patients in the comparison. In the previous study [3], an increase in vessel number was also a distinguishing feature from RA, as were lower macrophage numbers and a reduction in E-selectin expression. Kruithof and colleagues were unable to confirm these findings, which have been confirmed by others [4], but this may relate to issues of patient selection and to methods of quan
Introduction to the Special Series of Papers on Informing Each Other: Bridging the Gap between Researcher and Practitioners
Brian Fitzgerald
Informing Science The International Journal of an Emerging Transdiscipline , 2003,
Abstract: As an applied discipline, the gap between IS theory and practice is a potentially worrying one. This special series focuses on this gap, and the papers published consider the problems in some detail and how they might be addressed from a high level view and also in the context of specific initiatives which have been undertaken successfully. The issue is framed by this paper which considers the bipolar gap between theory and practice, a futile scenario in which both poles are ultimately cold.
Rese a de "Que se queden allá: El gobierno de México y la repatriación de mexicanos en Estados Unidos (1934-1940)" de Fernando Saúl Alanís Enciso
David Fitzgerald
Migraciones internacionales , 2009,
Asthma guidelines: Global to local
FitzGerald J
Annals of Thoracic Medicine , 2009,
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