995 research outputs found

    Objective effect manifestation of pectus excavatum on load-stressed pulmonary function testing: a case report

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    Abstract Introduction Pectus excavatum is the most common congenital deformity of the anterior chest wall that, under certain conditions, may pose functional problems due to cardiopulmonary compromise and exercise intolerance. Case presentation We present the case of an otherwise physically-adept 21-year-old Chinese sportsman with idiopathic pectus excavatum, whose symptoms manifested only on bearing a loaded body vest and backpack during physical exercise. Corroborative objective evidence was obtained via load-stressed pulmonary function testing, which demonstrated restrictive lung function. Conclusion This report highlights the possible detrimental synergism of thoracic load stress and pectus excavatum on cardiopulmonary function. Thoracic load-stressed pulmonary function testing provides objective evidence in support of such a synergistic relationship.</p

    Inherited biotic protection in a Neotropical pioneer plant

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    Chelonanthus alatus is a bat-pollinated, pioneer Gentianaceae that clusters in patches where still-standing, dried-out stems are interspersed among live individuals. Flowers bear circum-floral nectaries (CFNs) that are attractive to ants, and seed dispersal is both barochorous and anemochorous. Although, in this study, live individuals never sheltered ant colonies, dried-out hollow stems - that can remain standing for 2 years - did. Workers from species nesting in dried-out stems as well as from ground-nesting species exploited the CFNs of live C. alatus individuals in the same patches during the daytime, but were absent at night (when bat pollination occurs) on 60.5% of the plants. By visiting the CFNs, the ants indirectly protect the flowers - but not the plant foliage - from herbivorous insects. We show that this protection is provided mostly by species nesting in dried-out stems, predominantly Pseudomyrmex gracilis. That dried-out stems remain standing for years and are regularly replaced results in an opportunistic, but stable association where colonies are sheltered by one generation of dead C. alatus while the live individuals nearby, belonging to the next generation, provide them with nectar; in turn, the ants protect their flowers from herbivores. We suggest that the investment in wood by C. alatus individuals permitting stillstanding, dried-out stems to shelter ant colonies constitutes an extended phenotype because foraging workers protect the flowers of live individuals in the same patch. Also, through this process these dried-out stems indirectly favor the reproduction (and so the fitness) of the next generation including both their own offspring and that of their siblings, alladding up to a potential case of inclusive fitness in plants

    Robustness of circadian clocks to daylight fluctuations: hints from the picoeucaryote Ostreococcus tauri

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    The development of systemic approaches in biology has put emphasis on identifying genetic modules whose behavior can be modeled accurately so as to gain insight into their structure and function. However most gene circuits in a cell are under control of external signals and thus quantitative agreement between experimental data and a mathematical model is difficult. Circadian biology has been one notable exception: quantitative models of the internal clock that orchestrates biological processes over the 24-hour diurnal cycle have been constructed for a few organisms, from cyanobacteria to plants and mammals. In most cases, a complex architecture with interlocked feedback loops has been evidenced. Here we present first modeling results for the circadian clock of the green unicellular alga Ostreococcus tauri. Two plant-like clock genes have been shown to play a central role in Ostreococcus clock. We find that their expression time profiles can be accurately reproduced by a minimal model of a two-gene transcriptional feedback loop. Remarkably, best adjustment of data recorded under light/dark alternation is obtained when assuming that the oscillator is not coupled to the diurnal cycle. This suggests that coupling to light is confined to specific time intervals and has no dynamical effect when the oscillator is entrained by the diurnal cycle. This intringuing property may reflect a strategy to minimize the impact of fluctuations in daylight intensity on the core circadian oscillator, a type of perturbation that has been rarely considered when assessing the robustness of circadian clocks

    Approaches to discontinuing efalizumab: an open-label study of therapies for managing inflammatory recurrence

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    BACKGROUND: Efalizumab is a humanised recombinant monoclonal IgG1 antibody for the treatment of moderate-to-severe plaque psoriasis. When treatment discontinuation is necessary, however, some patients may experience inflammatory recurrence of the disease, which can progress to rebound if untreated. This analysis evaluated approaches for managing inflammatory recurrence after discontinuation of efalizumab. METHODS: An open-label, multicentre, investigational study was performed in 41 patients with moderate-to-severe plaque psoriasis who had recently completed clinical studies with efalizumab and had developed signs of inflammatory recurrence following abrupt cessation of treatment. Patients were assigned by the attending physicians to receive one of five standardised alternative systemic psoriasis treatment regimens for 12 weeks. Efficacy of the different therapy options was assessed using the physician's global assessment (PGA) of change over time. RESULTS: More favourable PGA responses were observed in patients changing to cyclosporin (PGA of 'good', 'excellent' or 'cleared': 7/10 patients, 70.0%) or methotrexate (9/20, 45.0%), compared with those receiving systemic corticosteroids (2/8, 25.0%), retinoids (0/1, 0.0%) or combined corticosteroids plus methotrexate (0/2, 0.0%). While the majority (77.8%) of patients showed inflammatory morphology at baseline, following 12 weeks of the alternative therapies the overall prevalence of inflammatory disease was decreased to 19.2%. CONCLUSION: Inflammatory recurrence after discontinuation of efalizumab therapy is a manageable event, with a number of therapies and approaches available to physicians, including short courses of cyclosporin or methotrexate

    Associations Between Very Low Concentrations of LDL-Cholesterol, hs-CRP and Health Outcomes in the Reasons for Geographical and Racial Differences in Stroke (REGARDS) Study

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    Introduction: Recent findings have demonstrated the important contribution of inflammation to the risk of cardiovascular disease (CVD) in individuals with optimally managed low density lipoprotein cholesterol (LDL-C). We explored relationships between LDL-C, high sensitivity C-reactive protein (hsCRP) and clinical outcomes in a free-living US population. Methods: We used data from the REasons for Geographical And Racial Differences in Stroke (REGARDS), and selected individuals at “high risk” for coronary events with a Framingham Coronary Risk Score of >10% or atherosclerotic cardiovascular disease (ASCVD) risk >7.5% in order to explore relationships between low LDL-C (70 mg/dl [1.8 mmol/L]); hs-CRP <2 compared to ≥2 mg/L and clinical outcomes (all-cause mortality, incident coronary heart disease [CHD] and incident stroke). To assess the association between the LDL-C and hs-CRP categories and each outcome, a series of incremental Cox proportional hazards models were employed on complete cases. To account for missing observations, the most adjusted model was used to interrogate the data using multiple imputation with chained equations (MICE). Results: In this analysis, 6136 REGARDS high risk participants were included. In the MICE analysis, participants with high LDL-C (>70 mg/dl) and low hs-CRP (<2 mg/L) had a lower risk of incident stroke (hazard ratio [HR] 0.69, 0.47-0.997) incident CHD (HR 0.71, 0.53- 0.95) and CHD death (HR 0.70, 0.50-0.99) than those in the same LDL-C category high hs- CRP (≥2 mg/L). In participants with high hsCRP (≥2 mg/dL), low LDL-C (<70 mg/dL [1.8 mmol/L]) was not associated with additional risk reduction of any investigated outcome, but with the significant increase of all-cause mortality (HR 1.37, 1.07-1.74). Conclusions: In this high-risk population, we found that low hsCRP (<2mg/L) appeared to be associated with reduced risk of incident stroke, incident CHD and CHD death, whereas low LDL-C (<70 mg/dL) was not associated with protective effects. Thus, our results support other data with respect to the importance of inflammatory processes in the pathogenesis of CVD

    Small bowel enteroclysis with magnetic resonance imaging and computed tomography in patients with failed and uncertain passage of a patency capsule

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    <p>Abstract</p> <p>Background</p> <p>Video capsule enteroscopy (VCE) has revolutionized small bowel imaging, enabling visual examination of the mucosa of the entire small bowel, while MR enteroclysis (MRE) and CT enteroclysis (CTE) have largely replaced conventional barium enteroclysis. A new indication for MRE and CTE is the clinical suspicion of small bowel strictures, as indicated by delayed or non-delivery of a test capsule given before a VCE examination, to exclude stenosis. The aim of this study was to determine the clinical value of subsequent MRE and CTE in patients in whom a test capsule did not present itself in due time.</p> <p>Methods</p> <p>Seventy-five consecutive patients were identified with a delayed or unnoticed delivery of the test capsule. Seventy patients consented to participate and underwent MRE (44) or CTE (26). The medical records and imaging studies were retrospectively reviewed and symptoms, laboratory results and imaging findings recorded.</p> <p>Results</p> <p>Lesions compatible with Crohns disease were shown by MRE in 5 patients, by CTE in one and by VCE in four, one of whom had lesions on MRE. In patients without alarm symptoms and findings (weight loss, haematochezia, anaemia, nocturnal diarrheoa, ileus, fistula, abscess and abnormal blood tests) imaging studies did not unveil any such lesion. VCE's were performed in only 20 patients, mainly younger than 50 years of age, although no stenotic lesion was shown by MRE and CTE. In the remaining 50 patients no VCE or other endoscopic intervention was performed indicating that the referring physician was content with the diagnostic information from MRE or CTE.</p> <p>Conclusion</p> <p>The diagnostic value of MRE and CTE is sufficient for clinical management of most patients with suspected small bowel disease, and thus VCE may be omitted or at least postponed for later usage.</p

    The Beneficial Effects of Antifreeze Proteins in the Vitrification of Immature Mouse Oocytes

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    Antifreeze proteins (AFPs) are a class of polypeptides that permit organismal survival in sub-freezing environments. The purpose of this study was to investigate the effect of AFP supplementation on immature mouse oocyte vitrification. Germinal vesicle-stage oocytes were vitrified using a two-step exposure to equilibrium and vitrification solution in the presence or absence of 500 ng/mL of AFP III. After warming, oocyte survival, in vitro maturation, fertilization, and embryonic development up to the blastocyst stage were assessed. Spindle and chromosome morphology, membrane integrity, and the expression levels of several genes were assessed in in vitro matured oocytes. The rate of blastocyst formation was significantly higher and the number of caspase-positive blastomeres was significantly lower in the AFP-treated group compared with the untreated group. The proportion of oocytes with intact spindles/chromosomes and stable membranes was also significantly higher in the AFP group. The AFP group showed increased Mad2, Hook-1, Zar1, Zp1, and Bcl2 expression and lower Eg5, Zp2, Caspase6, and Rbm3 expression compared with the untreated group. Supplementation of the vitrification medium with AFP has a protective effect on immature mouse oocytes, promoting their resistance to chilling injury. AFPs may preserve spindle forming ability and membrane integrity at GV stage. The fertilization and subsequent developmental competence of oocytes may be associated with the modulation of Zar1, Zp1/Zp2, Bcl2, Caspase6, and Rbm3

    Maltreated children use more grammatical negations

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    Many studies reveal a strong impact of childhood maltreatment on language development, mainly resulting in shorter utterances, less rich vocabulary, or a delay in grammatical complexity. However, different theories suggest the possibility for resilience – a positive adaptation to an otherwise adverse environment – in children who experienced childhood maltreatment. Here, we investigated different measures for language development in spontaneous speech, examining whether childhood maltreatment leads to a language deficit only or whether it can also result in differences in language use due to a possible adaptation to a toxic environment. We compared spontaneous speech during therapeutic peer-play sessions of 32 maltreated and 32 non-maltreated children from the same preschool and equivalent in gender, age (2 to 5 years), home neighborhood, ethnicity, and family income. Maltreatment status was reported by formal child protection reports, and corroborated by independent social service reports. We investigated general language sophistication (i.e., vocabulary, talkativeness, mean length of utterance), as well as grammatical development (i.e., use of plurals, tense, grammatical negations). We found that maltreated and non-maltreated children showed similar sophistication across all linguistic measures, except for the use of grammatical negations. Maltreated children used twice as many grammatical negations as non-maltreated children. The use of this highly complex grammatical structure shows an advanced linguistic skill, which shows that childhood maltreatment does not necessarily lead to a language deficit. The result might indicate the development of a negativity bias in the structure of spontaneous language due to an adaptation to their experiences
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