963 resultados para R.D. FitzGerald


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Neuropathic pain is a major health issue and is frequently accompanied by allodynia (painful sensations in response to normally non-painful stimulations), and unpleasant paresthesia/dysesthesia, pointing to alterations in sensory pathways normally dedicated to the processing of non-nociceptive information. Interestingly, mounting evidence indicate that central glial cells are key players in allodynia, partly due to changes in the astrocytic capacity to scavenge extracellular glutamate and gamma-aminobutyric acid (GABA), through changes in their respective transporters (EAAT and GAT). In the present study, we investigated the glial changes occurring in the dorsal column nuclei, the major target of normally innocuous sensory information, in the rat spared nerve injury (SNI) model of neuropathic pain. We report that together with a robust microglial and astrocytic reaction in the ipsilateral gracile nucleus, the GABA transporter GAT-1 is upregulated with no change in GAT-3 or glutamate transporters. Furthermore, [(3)H] GABA reuptake on crude synaptosome preparation shows that transporter activity is functionally increased ipsilaterally in SNI rats. This GAT-1 upregulation appears evenly distributed in the gracile nucleus and colocalizes with astrocytic activation. Neither glial activation nor GAT-1 modulation was detected in the cuneate nucleus. Together, the present results point to GABA transport in the gracile nucleus as a putative therapeutic target against abnormal sensory perceptions related to neuropathic pain.

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On June 26-27, 2006, 60 academic and industry scientists gathered during the PROSAFE workshop to discuss recommendations on taxonomy, antibiotic resistance, in vitro assessment of virulence and in vivo assessment of safety of probiotics used for human consumption. For identification of lactic acid bacteria (LAB) intended for probiotic use, it was recommended that conventional biochemical methods should be complemented with molecular methods and that these should be performed by an expert lab. Using the newly developed LAB Susceptibility test Medium (LSM), tentative epidemiological cut-off values were proposed. It was recommended that potentially probiotic strains not belonging to the wildtype distributions of relevant antimicrobials should not be developed as future products for human or animal consumption. Furthermore, it was recommended that the use of strains harbouring known and confirmed virulence genes should be avoided. Finally, for in vivo assessment of safety by investigating strain pathogenicity in animal models, the rat endocarditis model appeared to be the most reliable model tested in the PROSAFE project. Moreover, consensus was reached for approving the necessity of a human colonisation study in a randomised placebo-controlled double-blind design; however, further discussions are needed on the details of such as study.

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Medical implants, like cardiovascular devices, improve the quality of life for countless individuals but may become infected with bacteria like Staphylococcus aureus. Such infections take the form of a biofilm, a structured community of bacterial cells adherent to the surface of a solid substrate. Every biofilm begins with an attractive force or bond between bacterium and substratum. We used atomic force microscopy to probe experimentally forces between a fibronectin-coated surface (i.e., proxy for an implanted cardiac device) and fibronectin-binding receptors on the surface of individual living bacteria from each of 80 clinical isolates of S. aureus. These isolates originated from humans with infected cardiac devices (CDI; n = 26), uninfected cardiac devices (n = 20), and the anterior nares of asymptomatic subjects (n = 34). CDI isolates exhibited a distinct binding-force signature and had specific single amino acid polymorphisms in fibronectin-binding protein A corresponding to E652D, H782Q, and K786N. In silico molecular dynamics simulations demonstrate that residues D652, Q782, and N786 in fibronectin-binding protein A form extra hydrogen bonds with fibronectin, complementing the higher binding force and energy measured by atomic force microscopy for the CDI isolates. This study is significant, because it links pathogenic bacteria biofilms from the length scale of bonds acting across a nanometer-scale space to the clinical presentation of disease at the human dimension.

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[cat] Aquest projecte és una continuació del programa de recerca iniciat amb el projecte de R+D "School+ more than a platform to build the school of tomorrow" (IST-2000-25162) parcialment finançat per la Unió Europea a través de la convocatòria L'Escola del Demà, del Programa de Tecnologies de la Societat de la Informació del 5è Programa Marc. Aquesta iniciativa va ser seguida i aprofundida amb el projecte "Aprenentatge per a la comprensió en entorns virtuals als centres de secundària: la Xarxa School+", parcialment finançat pel DURSI a través de la convocatòria ARIE 2004. En aquest sentit, s'inscriu sota el mateix paraigües epistemològic (sociocultural) i metodològic (construccionista) dels projectes anteriors, i es basa en la utilització de diferents tipus d'evidències,en aquest cas però prestant especial atenció a la qüestió de l'avaluació de l'aprenentatge per a la comprensió i la dotació de sentit. En aquest context adquireix especial rellevància la idea del portafoli -o e-portafoli, webfoli, portafoli electrònic o digital- com a estratègia avaluadora de la comprensió i afavoridora de formes més complexes d'aprenentatge. En aquest informe, i d¿acord amb allò manifestat al projecte de recerca, es donen respostes a les següents qüestions: (a) quines són les possibilitats i les limitacions del portafoli electrònic com a sistema per avaluar processos d'aprenentatge de caràcter complex, orientats a la comprensió i la dotació de sentit; (b) com tenen lloc els processos d'innovació i millora a l'ensenyament secundari quan es fan servir entorns virtuals d'informació i comunicació, i es persegueix el desenvolupament d'un model pedagògic i curricular de caràcter interdisciplinari;(c) quins processos pedagògics, organitzatius, cognitius i emocionals estan implicats en les situacions d'aprenentatge orientades a la comprensió i la dotació de sentit, i no en la memorització i repetició de continguts; (d) com es desenvolupen experiències de col·laboració entre professors, estudiants i centres de secundària.

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Advances in Near-surface Seismology and Ground-penetrating Radar (SEG Geophysical Developments Series No. 15) is a collection of original papers by renowned and respected authors from around the world. Technologies used in the application of near-surface seismology and ground-penetrating radar have seen significant advances in the last several years. Both methods have benefited from new processing tools, increased computer speeds, and an expanded variety of applications. This book, divided into four sections ? ?Reviews,? ?Methodology,? ?Integrative Approaches,? and ?Case Studies? ? captures the most significant cutting-edge issues in active areas of research, unveiling truly pertinent studies that address fundamental applied problems. This collection of manuscripts grew from a core group of papers presented at a postconvention workshop, ?Advances in Near-surface Seismology and Ground-penetrating Radar,? held during the 2009 SEG Annual Meeting in Houston, Texas. This is the first cooperative publication effort between the near-surface communities of SEG, AGU, and EEGS. It will appeal to a large and diverse audience that includes researchers and practitioners inside and outside the near-surface geophysics community.

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Medulloblastoma, the most common malignant paediatric brain tumour, is currently treated with nonspecific cytotoxic therapies including surgery, whole-brain radiation, and aggressive chemotherapy. As medulloblastoma exhibits marked intertumoural heterogeneity, with at least four distinct molecular variants, previous attempts to identify targets for therapy have been underpowered because of small samples sizes. Here we report somatic copy number aberrations (SCNAs) in 1,087 unique medulloblastomas. SCNAs are common in medulloblastoma, and are predominantly subgroup-enriched. The most common region of focal copy number gain is a tandem duplication of SNCAIP, a gene associated with Parkinson's disease, which is exquisitely restricted to Group 4α. Recurrent translocations of PVT1, including PVT1-MYC and PVT1-NDRG1, that arise through chromothripsis are restricted to Group 3. Numerous targetable SCNAs, including recurrent events targeting TGF-β signalling in Group 3, and NF-κB signalling in Group 4, suggest future avenues for rational, targeted therapy.

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AIM: To report the results of whole anterior segment proton beam radiotherapy (PBR) for diffuse iris melanoma. METHODS: Between 2000 and 2011, 12 patients with iris melanoma received PBR to the entire iris and ciliary body. RESULTS: Patients had a mean age of 57 years and a median follow-up of 3.5 years (range 1-11.6 years). Tumour iris involvement was 1-4 h in five patients, 5-8 h in four and 9-12 h in three. Angle involvement was 6-8 h in five patients and 9-12 h in seven. The visual acuity (VA) before treatment was 6/5-6/6 in six patients, 6/8-6/9 in three and 6/18-6/38 in three. No tumour recurrence occurred during the follow-up period. Glaucoma treatment was required in 11 of 12 patients. The visual acuity at the last follow-up was 6/5-6/9 in five patients, 6/18-6/24 in three, 6/60-1/60 in two and no light perception in two. Four patients developed varying non-severe degrees of limbal stem cell deficiency, which was treatable with conservative measures. CONCLUSIONS: Whole anterior segment PBR is a useful alternative to enucleation for diffuse iris melanoma. Most patients will need treatment for glaucoma and some may require treatment for tear-film instability and/or stem cell failure.

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[cat] Aquest projecte és una continuació del programa de recerca iniciat amb el projecte de R+D "School+ more than a platform to build the school of tomorrow" (IST-2000-25162) parcialment finançat per la Unió Europea a través de la convocatòria L'Escola del Demà, del Programa de Tecnologies de la Societat de la Informació del 5è Programa Marc. Aquesta iniciativa va ser seguida i aprofundida amb el projecte "Aprenentatge per a la comprensió en entorns virtuals als centres de secundària: la Xarxa School+", parcialment finançat pel DURSI a través de la convocatòria ARIE 2004. En aquest sentit, s'inscriu sota el mateix paraigües epistemològic (sociocultural) i metodològic (construccionista) dels projectes anteriors, i es basa en la utilització de diferents tipus d'evidències,en aquest cas però prestant especial atenció a la qüestió de l'avaluació de l'aprenentatge per a la comprensió i la dotació de sentit. En aquest context adquireix especial rellevància la idea del portafoli -o e-portafoli, webfoli, portafoli electrònic o digital- com a estratègia avaluadora de la comprensió i afavoridora de formes més complexes d'aprenentatge. En aquest informe, i d¿acord amb allò manifestat al projecte de recerca, es donen respostes a les següents qüestions: (a) quines són les possibilitats i les limitacions del portafoli electrònic com a sistema per avaluar processos d'aprenentatge de caràcter complex, orientats a la comprensió i la dotació de sentit; (b) com tenen lloc els processos d'innovació i millora a l'ensenyament secundari quan es fan servir entorns virtuals d'informació i comunicació, i es persegueix el desenvolupament d'un model pedagògic i curricular de caràcter interdisciplinari;(c) quins processos pedagògics, organitzatius, cognitius i emocionals estan implicats en les situacions d'aprenentatge orientades a la comprensió i la dotació de sentit, i no en la memorització i repetició de continguts; (d) com es desenvolupen experiències de col·laboració entre professors, estudiants i centres de secundària.

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[cat] Aquest projecte és una continuació del programa de recerca iniciat amb el projecte de R+D "School+ more than a platform to build the school of tomorrow" (IST-2000-25162) parcialment finançat per la Unió Europea a través de la convocatòria L'Escola del Demà, del Programa de Tecnologies de la Societat de la Informació del 5è Programa Marc. Aquesta iniciativa va ser seguida i aprofundida amb el projecte "Aprenentatge per a la comprensió en entorns virtuals als centres de secundària: la Xarxa School+", parcialment finançat pel DURSI a través de la convocatòria ARIE 2004. En aquest sentit, s'inscriu sota el mateix paraigües epistemològic (sociocultural) i metodològic (construccionista) dels projectes anteriors, i es basa en la utilització de diferents tipus d'evidències,en aquest cas però prestant especial atenció a la qüestió de l'avaluació de l'aprenentatge per a la comprensió i la dotació de sentit. En aquest context adquireix especial rellevància la idea del portafoli -o e-portafoli, webfoli, portafoli electrònic o digital- com a estratègia avaluadora de la comprensió i afavoridora de formes més complexes d'aprenentatge. En aquest informe, i d¿acord amb allò manifestat al projecte de recerca, es donen respostes a les següents qüestions: (a) quines són les possibilitats i les limitacions del portafoli electrònic com a sistema per avaluar processos d'aprenentatge de caràcter complex, orientats a la comprensió i la dotació de sentit; (b) com tenen lloc els processos d'innovació i millora a l'ensenyament secundari quan es fan servir entorns virtuals d'informació i comunicació, i es persegueix el desenvolupament d'un model pedagògic i curricular de caràcter interdisciplinari;(c) quins processos pedagògics, organitzatius, cognitius i emocionals estan implicats en les situacions d'aprenentatge orientades a la comprensió i la dotació de sentit, i no en la memorització i repetició de continguts; (d) com es desenvolupen experiències de col·laboració entre professors, estudiants i centres de secundària.

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Background : Numerous studies have shown that immune cells infiltrate the spinal cord after peripheral nerve injury and that they play a major contribution to sensory hypersensitivity in rodents. In particular, the role of monocyte-derived cells and T lymphocytes seems to be prominent in this process. This exciting new perspective in research on neuropathic pain opens many different areas of work, including the understanding of the function of these cells and how they impact on neural function. However, no systematic description of the time course or cell types that characterize this infiltration has been published yet, although this seems to be the rational first step of an overall understanding of the phenomenon. Objective : Describe the time course and cell characteristics of T lymphocyte infiltration in the spinal cord in the Spared Nerve Injury (SNI) model of neuropathic pain in rats. Methods : Collect of lumbar spinal cords of rats at days 2, 7, 21 and 40 after SNI or sham operation (n=4). Immunofluorescence detecting different proteins of T cell subgroups (CD2+CD4+, CD2+CD8+, Th1 markers, Th2 markers, Th17 markers). Quantification of the infiltration rate of the different subgroups. Expected results : First, we expect to see an infiltration of T cells in the spinal cord ipsilateral to nerve injury, higher in SNI rats than in sham animals. Second, we anticipate that different subtypes of T cells penetrate at different time points. Finally, the number of T lymphocytes are expected to decrease at the latest time point, showing a resolution of the process underlying their infiltrating the spinal cord in the first place. Impact : A systematic description of the infiltration of T cells in the spinal cord after peripheral nerve injury is needed to have a better understanding of the role of immune cells in neuropathic pain. The time course that we want to establish will provide the scientific community with new perspectives. First, it will confirm that T cells do indeed infiltrate the spinal cord after SNI in rats. Second, the type of T cells infiltrating at different time points will give clues about their function, in particular their inflammatory or anti-inflammatory profile. From there on, other studies could be lead, investigating the functional side of the specific subtypes put to light by us. Ultimately, this could lead to the discovery of new drugs targeting T cells or their infiltration, in the hope of improving neuropathic pain.

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BACKGROUND: Aromatase inhibitors provide superior disease control when compared with tamoxifen as adjuvant therapy for postmenopausal women with endocrine-responsive early breast cancer. PURPOSE: To present the design, history, and analytic challenges of the Breast International Group (BIG) 1-98 trial: an international, multicenter, randomized, double-blind, phase-III study comparing the aromatase inhibitor letrozole with tamoxifen in this clinical setting. METHODS: From 1998-2003, BIG 1-98 enrolled 8028 women to receive monotherapy with either tamoxifen or letrozole for 5 years, or sequential therapy of 2 years of one agent followed by 3 years of the other. Randomization to one of four treatment groups permitted two complementary analyses to be conducted several years apart. The first, reported in 2005, provided a head-to-head comparison of letrozole versus tamoxifen. Statistical power was increased by an enriched design, which included patients who were assigned sequential treatments until the time of the treatment switch. The second, reported in late 2008, used a conditional landmark approach to test the hypothesis that switching endocrine agents at approximately 2 years from randomization for patients who are disease-free is superior to continuing with the original agent. RESULTS: The 2005 analysis showed the superiority of letrozole compared with tamoxifen. The patients who were assigned tamoxifen alone were unblinded and offered the opportunity to switch to letrozole. Results from other trials increased the clinical relevance about whether or not to start treatment with letrozole or tamoxifen, and analysis plans were expanded to evaluate sequential versus single-agent strategies from randomization. LIMITATIONS: Due to the unblinding of patients assigned tamoxifen alone, analysis of updated data will require ascertainment of the influence of selective crossover from tamoxifen to letrozole. CONCLUSIONS: BIG 1-98 is an example of an enriched design, involving complementary analyses addressing different questions several years apart, and subject to evolving analytic plans influenced by new data that emerge over time.

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BACKGROUND: High-risk sexual behaviors have been suggested as drivers of the recent dramatic increase of sexually transmitted hepatitis C virus (HCV) among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM). METHODS: We assessed the association between the genetic bottleneck of HIV at transmission and the prevalence and incidence of HCV coinfection in HIV-infected MSM from the Swiss HIV Cohort Study (SHCS). As a proxy for the width of the transmission bottleneck, we used the fraction of ambiguous nucleotides detected by genotypic resistance tests sampled during early HIV infection. We defined a broad bottleneck as a fraction of ambiguous nucleotides exceeding a previously established threshold (0.5%). RESULTS: From the SHCS, we identified 671 MSM with available results of HCV serologic tests and with an HIV genotypic resistance test performed during early HIV infection. Of those, 161 (24.0%) exhibited a broad HIV transmission bottleneck, 38 (5.7%) had at least 1 positive HCV test result, and 26 (3.9%) had an incident HCV infection. Individuals with broad HIV transmission bottlenecks exhibited a 2-fold higher odds of having ever experienced an HCV coinfection (odds ratio, 2.2 [95% confidence interval {CI}, 1.1-4.3]) and a 3-fold higher hazard of having an incident HCV infection (hazard ratio, 3.0 [95% CI, 1.4-6.6]) than individuals with narrow HIV transmission bottlenecks. CONCLUSIONS: Our results indicate that the currently occurring sexual spread of HCV is focused on MSM who are prone to exhibit broad HIV transmission bottlenecks. This is consistent with an important role of high-risk behavior and mucosal barrier impairment in the transmission of HCV among MSM.

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Melanoma is an aggressive disease with few standard treatment options. The conventional classification system for this disease is based on histological growth patterns, with division into four subtypes: superficial spreading, lentigo maligna, nodular, and acral lentiginous. Major limitations of this classification system are absence of prognostic importance and little correlation with treatment outcomes. Recent preclinical and clinical findings support the notion that melanoma is not one malignant disorder but rather a family of distinct molecular diseases. Incorporation of genetic signatures into the conventional histopathological classification of melanoma has great implications for development of new and effective treatments. Genes of the mitogen-associated protein kinase (MAPK) pathway harbour alterations sometimes identified in people with melanoma. The mutation Val600Glu in the BRAF oncogene (designated BRAF(V600E)) has been associated with sensitivity in vitro and in vivo to agents that inhibit BRAF(V600E) or MEK (a kinase in the MAPK pathway). Melanomas arising from mucosal, acral, chronically sun-damaged surfaces sometimes have oncogenic mutations in KIT, against which several inhibitors have shown clinical efficacy. Some uveal melanomas have activating mutations in GNAQ and GNA11, rendering them potentially susceptible to MEK inhibition. These findings suggest that prospective genotyping of patients with melanoma should be used increasingly as we work to develop new and effective treatments for this disease.