80 research outputs found

    Clinically aggressive central giant cell granulomas in two patients with neurofibromatosis 1

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    Background Neurofibromatosis 1 (NF1) is an autosomal dominantly inherited disorder caused by a spectrum of mutations affecting the Nf1 gene. Affected patients develop benign and malignant tumors at an increased frequency. Clinical findings include multiple cutaneous café-au-lait pigmentations, neurofibromas, axillary freckling, optic gliomas, benign iris hamartomas (Lisch nodules), scoliosis, and poorly defined soft tissue lesions of the skeleton. Kerl first reported an association of NF1 with multiple central giant cell granulomas (CGCGs) of the jaws. There have since been 4 additional published cases of NF1 patients with CGCGs of the jaws. Clinical cases We report on 2 patients who presented with NF1 and aggressive CGCGs of the jaws. In both cases, the clinical course was characterized by numerous recurrences despite mechanical curettage and surgical resection. Conclusions We review proposed mechanisms to explain the apparent association between NF1 and an increased incidence of CGCGs of the jaws. While the presence of CGCGs of the jaws in patients with NF1 could represent either a coincidental association or a true genetic linkage, we propose that this phenomenon is most likely related to NF1-mediated osseous dysplasia. Compared to normal bone, the Nf1-haploinsufficient bone in a patient with NF1 may be less able to remodel in response to as of yet unidentified stimuli (e.g. excessive mechanical stress and/or vascular fragility), and consequently may be more susceptible to developing CGCG-like lesions. Alternatively, the CGCG in NF1 patients could represent a true neoplasm, resulting from additional, as of yet unidentified, genetic alterations to Nf1-haploinsufficient bone

    Food abundance does not determine bird use of early-successional habitat.

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    Abstract. Few attempts have been made to experimentally address the extent to which temporal or spatial variation in food availability influences avian habitat use. We used an experimental approach to investigate whether bird use differed between treated (arthropods reduced through insecticide application) and control (untreated) forest canopy gaps within a bottomland hardwood forest in the Upper Coastal Plain of South Carolina, USA. Gaps were two- to three-year-old group selection timber harvest openings of three sizes (0.13, 0.26, and 0.50 ha). Our study was conducted during four bird use periods (spring migration, breeding, post-breeding, and fall migration) in 2002 and 2003. Arthropods were reduced in treated gaps by 68% in 2002 and 73% in 2003. We used mist-netting captures and foraging attack rates to assess the influence of arthropod abundance on avian habitat use. Evidence that birds responded to arthropod abundance was limited and inconsistent. In 2002, we generally captured more birds in treated gaps of the smallest size (0.13 ha) and fewer birds in treated gaps of the larger sizes. In 2003, we recorded few differences in the number of captures in treated and control gaps. Foraging attack rates generally were lower in treated than in control gaps, indicating that birds were able to adapt to the reduced food availability and remain in treated gaps. We conclude that arthropod abundance was not a proximate factor controlling whether forest birds used our gaps. The abundance of food resources may not be as important in determining avian habitat selection as previous research has indicated, at least for passerines in temperate subtropical regions

    Effect of alloy treatment and coiling temperature on microstructure and bending performance of ultra-high strength strip steel

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    Two different high strength B-containing microalloyed steel strips produced in industrial processing conditions, one treated with Ti and the other treated with Al, processed by controlled rolling, accelerated cooling and coiling in two different temperatures ranges [723 K to 733 K (450 °C to 460 °C)] and [633 K to 653 K (360 °C to 380 °C)] were subjected to bend testing. The Ti treated steel coiled at the higher temperature 733 K (460 °C) showed the best bending performance. The relatively softer (tensile strength of and even {112} in the sub-surface region as well as uniformity of through thickness texture of the rolled sheet improve the bendability. In the presence of crack initiators, like coarse and brittle TiN particles found in the Ti treated steel, a harder microstructure and the presence of Cube and Goss texture in the sub-surface layer, seen for the lower coiling temperature can cause local transgranular cleavage cracking. Finally the post-uniform elongation obtained from tensile testing and bendability follow a good correlation

    BHPR research: qualitative1. Complex reasoning determines patients' perception of outcome following foot surgery in rheumatoid arhtritis

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    Background: Foot surgery is common in patients with RA but research into surgical outcomes is limited and conceptually flawed as current outcome measures lack face validity: to date no one has asked patients what is important to them. This study aimed to determine which factors are important to patients when evaluating the success of foot surgery in RA Methods: Semi structured interviews of RA patients who had undergone foot surgery were conducted and transcribed verbatim. Thematic analysis of interviews was conducted to explore issues that were important to patients. Results: 11 RA patients (9 ♂, mean age 59, dis dur = 22yrs, mean of 3 yrs post op) with mixed experiences of foot surgery were interviewed. Patients interpreted outcome in respect to a multitude of factors, frequently positive change in one aspect contrasted with negative opinions about another. Overall, four major themes emerged. Function: Functional ability & participation in valued activities were very important to patients. Walking ability was a key concern but patients interpreted levels of activity in light of other aspects of their disease, reflecting on change in functional ability more than overall level. Positive feelings of improved mobility were often moderated by negative self perception ("I mean, I still walk like a waddling duck”). Appearance: Appearance was important to almost all patients but perhaps the most complex theme of all. Physical appearance, foot shape, and footwear were closely interlinked, yet patients saw these as distinct separate concepts. Patients need to legitimize these feelings was clear and they frequently entered into a defensive repertoire ("it's not cosmetic surgery; it's something that's more important than that, you know?”). Clinician opinion: Surgeons' post operative evaluation of the procedure was very influential. The impact of this appraisal continued to affect patients' lasting impression irrespective of how the outcome compared to their initial goals ("when he'd done it ... he said that hasn't worked as good as he'd wanted to ... but the pain has gone”). Pain: Whilst pain was important to almost all patients, it appeared to be less important than the other themes. Pain was predominately raised when it influenced other themes, such as function; many still felt the need to legitimize their foot pain in order for health professionals to take it seriously ("in the end I went to my GP because it had happened a few times and I went to an orthopaedic surgeon who was quite dismissive of it, it was like what are you complaining about”). Conclusions: Patients interpret the outcome of foot surgery using a multitude of interrelated factors, particularly functional ability, appearance and surgeons' appraisal of the procedure. While pain was often noted, this appeared less important than other factors in the overall outcome of the surgery. Future research into foot surgery should incorporate the complexity of how patients determine their outcome Disclosure statement: All authors have declared no conflicts of interes

    HMGB1 Enhances Immune Suppression by Facilitating the Differentiation and Suppressive Activity of Myeloid-Derived Suppressor Cells

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    Chronic inflammation often precedes malignant transformation and later drives tumor progression. Likewise, subversion of the immune system plays a role in tumor progression, with tumoral immune escape now well recognized as a crucial hallmark of cancer. Myeloid-derived suppressor cells (MDSC) are elevated in most individuals with cancer, where their accumulation and suppressive activity are driven by inflammation. Thus, MDSCs may define an element of the pathogenic inflammatory processes that drives immune escape. The secreted alarmin HMGB1 is a proinflammatory partner, inducer, and chaperone for many proinflammatory molecules that MDSCs develop. Therefore, in this study, we examined HMGB1 as a potential regulator of MDSCs. In murine tumor systems, HMGB1 was ubiquitous in the tumor microenvironment, activating the NF-kappa B signal transduction pathway in MDSCs and regulating their quantity and quality. We found that HMGB1 promotes the development of MDSCs from bone marrow progenitor cells, contributing to their ability to suppress antigendriven activation of CD4(+) and CD8(+) T cells. Furthermore, HMGB1 increased MDSC-mediated production of IL-10, enhanced crosstalk between MDSCs and macrophages, and facilitated the ability of MDSCs to down-regulate expression of the T-cell homing receptor L-selectin. Overall, our results revealed a pivotal role for HMGB1 in the development and cancerous contributions of MDSCs. (C) 2014 AACR

    Hemodynamic during resistance exercise sets and rest intervals in young and older men

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    Intense blood pressure elevations during resistance exercise (RE) could lead to risk of acute cardiovascular events. Since, the natural aging process contribute to rest and exercise elevations in BP it could be expected higher BP elevations following RE in older individuals. However, the studies have shown contradictory findings which are likely due to the time of BP assessment following exercise. Thus, we compared BP changes after each set and rest interval in young and older men. Sixteen men (8 each group) underwent four sets until fatigue at leg press equipment with high load (80% 1RM). BP was assessed, by finger photoplethysmography and the other cardiovascular measurements were estimated based on body characteristics. Systolic BP (SBP) and mean BP (MBP) increased more in older men at first sets; heart rate (HR) increased more in young during all sets and rest intervals; cardiac output (CO) maintained higher all the time in young; and total peripheral resistance (TPR) increased more during all sets in older men. Thus, the present study shows that RE performed to fatigue leads to higher BP increase in older men suggesting BP might be monitored during RE for safe proposal especially on this higher risk population.Intense blood pressure (BP) elevations during resistance exercise (RE) could lead to risk of acute cardiovascular events. Since, the natural aging process contribute to rest and exercise elevations in BP, higher BP elevations following RE could be expected in older individuals. However, previous studies have shown contradictory findings which are likely due to the time of BP assessment following exercise. Thus, we compared BP changes after each set and rest interval in young and older men. Sixteen men (8 each group) underwent four sets until fatigue at leg press equipment with high load (80% 1RM). BP was assessed, by finger photoplethysmography and the other cardiovascular measurements were estimated based on individual characteristics. Systolic BP (SBP) and mean BP (MBP) increased more in older men at first sets; heart rate (HR) increased more in young during all sets and rest intervals; cardiac output (CO) maintained higher all the time in young; and total peripheral resistance (TPR) increased more during all sets in older men. Thus, the present study shows that RE performed to fatigue leads to higher BP increase in older men suggesting BP might be monitored during RE for safety reasons especially on this higher risk population
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