444 research outputs found

    Cellular maturation defects in Bruton's tyrosine kinase-deficient immature B cells are amplified by premature B cell receptor expression and reduced by receptor editing

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    In the mouse, Bruton's tyrosine kinase (Btk) is essential for efficient developmental progression of CD43(+)CD2(-) large cycling into CD43(-)CD2(+) small resting pre-B cells in the bone marrow and of IgM(high) transitional type 2 B cells into IgM(low) mature B cells in the spleen. In this study, we show that the impaired induction of cell surface changes in Btk-deficient pre-B cells was still noticeable in kappa(+) immature B cells, but was largely corrected in lambda(+) immature B cells. As lambda gene rearrangements are programmed to follow kappa rearrangements and lambda expression is associated with receptor editing, we hypothesized that the transit time through the pre-B cell compartment or receptor editing may affect the extent of the cellular maturation defects in Btk-deficient B cells. To address this issue, we used 3-83 mu delta transgenic mice, which prematurely express a complete B cell receptor and therefore manifest accelerated B cell development. In Btk-deficient 3-83 mu delta mice, the IgM(+) B cells in the bone marrow exhibited a very immature phenotype (pre-BCR(+)CD43(+)CD2(-)) and were arrested at the transitional type 1 B cell stage upon arrival in the spleen. However, these cellular maturation defects were largely restored when Btk-deficient 3-83 mu delta B cells were on a centrally deleting background and therefore targeted for receptor editing. Providing an extended time window for developing B cells by enforced expression of the antiapoptotic gene Bcl-2 did not alter the Btk dependence of their cellular maturation. We conclude that premature B cell receptor expression amplifies the cellular maturation defects in Btk-deficient B cells, while extensive receptor editing reduces these defects

    Can verbal suggestions strengthen the effects of a relaxation intervention?

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    Short stress management interventions such as relaxation therapy have demonstrated preliminary effectiveness in reducing stress-related problems. A promising tool to strengthen the effectiveness of relaxation-based interventions is the use of verbal suggestions, as previous research provided evidence that verbal suggestions can induce positive outcome expectancies, facilitate adaptive responses to stress and improve health outcomes. The present experimental proof-of-concept study aimed to investigate the effects of a brief relaxation intervention and specifically the role of verbal suggestions on stress-related outcomes assessed by self-report questionnaires and psychophysiological data. 120 participants (mean age = 22.1 years) were randomized to one of four intervention conditions: a brief relaxation intervention plus verbal suggestions condition, a brief relaxation intervention only condition, a verbal suggestions only condition, and a control condition. Afterwards, participants were subjected to a psychosocial stress challenge to assess reactivity to a stressful event. Immediately after both relaxation interventions (with and without verbal suggestions), lower self-reported state anxiety was found compared to the control condition, but no differences were observed in response to the stressor. The verbal suggestions only condition did not impact state anxiety. No significant effects were found for verbal suggestion interventions on cortisol, alpha amylase, heart rate and skin conductance. This is the first study investigating the role of verbal suggestions in the effectiveness of a brief relaxation intervention. Although this experimental proof-of-concept study provides support for the effectiveness of a brief relaxation intervention in lowering state anxiety directly after the intervention, the effects did not impact the response to a subsequent stressor and we did not observe any evidence for the add-on effectiveness of verbal suggestions. The effectiveness of brief relaxation interventions on stress responses should be investigated further in future research by incorporating interventions that are tailored to the specific stress challenge and various types of verbal suggestions

    Tumor suppressor function of Bruton tyrosine kinase is independent of its catalytic activity

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    During B-cell development in the mouse, Bruton tyrosine kinase (Btk) and the adaptor protein SLP-65 (Src homology 2 [SH2] domain-containing leukocyte protein of 65 kDa) limit the expansion and promote the differentiation of pre-B cells. Btk is thought to mainly function by phosphorylating phospholipase Cgamma2, which is brought into close proximity of Btk by SLP-65. However, this model was recently challenged by the identification of a role for Btk as a tumor suppressor in the absence of SLP-65 and by the finding that Btk function is partially independent of its kinase activity. To investigate if enzymatic activity is critical for the tumor suppressor function of Btk, we crossed transgenic mice expressing the kinase-inactive K430R-Btk mutant onto a Btk/SLP-65 double-deficient background. We found that K430R-Btk expression rescued the severe developmental arrest at the pre-B-cell stage in Btk/SLP-65 double-deficient mice. Moreover, K430R-Btk co

    Analysis of a rapid load test on an instrumented bored pile in clay

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    Rapid load testing methods for piled foundations are generally easier and quicker to mobilise than classic static tests, and are less complex to analyse than dynamic load tests. A recently developed rapid load pile testing method known as the Statnamic test is seeing greater use in the UK for the assessment of piles. For foundation design, it is necessary to derive the equivalent static load-settlement curve from the rapid load test data by eliminating inertial and damping effects. Existing methods of test analysis generally provide good correlation with static tests for sands and gravels, but overpredict pile capacities by up to 50% for clays. In order to gain an insight into the behaviour of rapid load pile testing in clays, a full-scale pile instrumented with accelerometers, strain-gauged sister bars and a tip load cell was tested in a glacial lodgement till near Grimsby, UK. The soil around the pile was also instrumented with radially arrayed buried accelerometers. The test pile was subjected to rapid loading tests, the results of which were compared with constant rate of penetration and maintained load static tests on the same pile. Results from the field testing have been analysed using non-linear viscous parameters obtained from laboratory model and element tests to represent rate-dependent clay shear resistance in the post-yield phase of loading. Shaft frictions derived from the strain-gauged reinforcement in the pile have been compared with shear strains and stresses derived from accelerations in the surrounding soil to give an insight into the load transfer mechanisms for a rapidly loaded pile in clay.Permission is granted by ICE Publishing to print one copy for personal use. Any other use of these PDF files is subject to reprint fees.http://www.icevirtuallibrary.com/content/journal

    Gene expression analysis of peripheral cells for subclassification of pediatric inflammatory bowel disease in remission

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    Objective: In current clinical practice, optimal treatment of inflammatory bowel disease (IBD) aims at the induction and maintenance of clinical remission. Clinical remission is apparent when laboratory markers of inflammation are normal and clinical symptoms are absent. However, sub-clinical inflammation can still be present. A detailed analysis of the immune status during this inactive state of disease may provide a useful tool to categorize patients with clinical remission into subsets with variable states of immune activation. Design: By using Affymetrix GeneChips, we analysed RNA gene expression profiles of peripheral blood leukocytes from pediatric IBD patients in clinical remission and controls. We performed (un)supervised clustering analysis of IBD-associated genes and applied Ingenuity® pathway software to identify specific molecular profiles between patients. Results: Pediatric IBD patients with disease in clinical remission display heterogeneously distributed gene expression profiles that are significantly distinct from controls. We identified three clusters of IBD patients, each displaying specific expression profiles of IBD-associated genes. Conclusion: The expression of immune- and IBD-associated genes in peripheral blood leukocytes from pediatric IBD patients in clinical remission was different from healthy controls, indicating that sub-clinical immune mechanisms are still active during remission. As such, RNA profiling of peripheral blood may allow for non-invasive patient subclassification and new perspectives in treatment regimes of IBD patients in the future

    Btk at the Pre-B Cell Receptor Checkpoint

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    Signalling from the BCR or its immature form, the pre-BCR, was shown to be crucial for B cell development. Gene-targeted mice have defined differential roles of components of the (pre-) BCR complex or its downstream signalling pathways. One of the proteins involved in (pre-) BCR signalling is the cytoplasmic protein Bruton’s tyrosine kinase (Btk). Mice deficient in Btk have B cell differentiation defects resulting in an X-linked immunodefi ciency (xid) phenotype. The xid phenotype is characterized by a reduction in the number of peripheral B cells and the residual B cell have an immature phenotype, indicating that the lack of Btk causes a block in peripheral B cell

    Human enteroids: Preclinical models of non-inflammatory diarrhea

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    Researchers need an available and easy-to-use model of the human intestine to better understand human intestinal physiology and pathophysiology of diseases, and to offer an enhanced platform for developing drug therapy. Our work employs human enteroids derived from each of the major intestinal sections to advance understanding of several diarrheal diseases, including those caused by cholera, rotavirus and enterohemorrhagic Escherichia coli. An enteroid bank is being established to facilitate comparison of segmental, developmental, and regulatory differences in transport proteins that can influence therapy efficacy. Basic characterization of major ion transport protein expression, localization and function in the human enteroid model sets the stage to study the effects of enteric infection at the transport level, as well as to monitor potential responses to pharmacological intervention

    Predictors of Intraspinal Pressure and Optimal Cord Perfusion Pressure After Traumatic Spinal Cord Injury.

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    BACKGROUND/OBJECTIVES: We recently developed techniques to monitor intraspinal pressure (ISP) and spinal cord perfusion pressure (SCPP) from the injury site to compute the optimum SCPP (SCPPopt) in patients with acute traumatic spinal cord injury (TSCI). We hypothesized that ISP and SCPPopt can be predicted using clinical factors instead of ISP monitoring. METHODS: Sixty-four TSCI patients, grades A-C (American spinal injuries association Impairment Scale, AIS), were analyzed. For 24 h after surgery, we monitored ISP and SCPP and computed SCPPopt (SCPP that optimizes pressure reactivity). We studied how well 28 factors correlate with mean ISP or SCPPopt including 7 patient-related, 3 injury-related, 6 management-related, and 12 preoperative MRI-related factors. RESULTS: All patients underwent surgery to restore normal spinal alignment within 72 h of injury. Fifty-one percentage had U-shaped sPRx versus SCPP curves, thus allowing SCPPopt to be computed. Thirteen percentage, all AIS grade A or B, had no U-shaped sPRx versus SCPP curves. Thirty-six percentage (22/64) had U-shaped sPRx versus SCPP curves, but the SCPP did not reach the minimum of the curve, and thus, an exact SCPPopt could not be calculated. In total 5/28 factors were associated with lower ISP: older age, excess alcohol consumption, nonconus medullaris injury, expansion duroplasty, and less intraoperative bleeding. In a multivariate logistic regression model, these 5 factors predicted ISP as normal or high with 73% accuracy. Only 2/28 factors correlated with lower SCPPopt: higher mean ISP and conus medullaris injury. In an ordinal multivariate logistic regression model, these 2 factors predicted SCPPopt as low, medium-low, medium-high, or high with only 42% accuracy. No MRI factors correlated with ISP or SCPPopt. CONCLUSIONS: Elevated ISP can be predicted by clinical factors. Modifiable factors that may lower ISP are: reducing surgical bleeding and performing expansion duroplasty. No factors accurately predict SCPPopt; thus, invasive monitoring remains the only way to estimate SCPPopt

    Attachment styles of dermatological patients in europe : A multicentre study in 13 countries

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    This is an Open Access article, distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License https://creativecommons.org/licenses/by-nc/4.0/. © 2017 Acta Dermato-Venereologica.Attachment styles of dermatological outpatients and satisfaction with their dermatologists were investigated within the framework of a multicentre study conducted in 13 European countries, organized by the European Society for Dermatology and Psychiatry. Attachment style was assessed with the Adult Attachment Scale. Patient satisfaction with the dermatologist was assessed with an 11-degree scale. A total of 3,635 adult outpatients and 1,359 controls participated in the study. Dermatological outpatients were less able to depend on others, were less comfortable with closeness and intimacy, and experienced similar rates of anxiety in relationships as did the controls. Participants who had secure attachment styles reported stressful life events during the last 6 months significantly less often than those who had insecure attachment styles. Patients with secure attachment styles tended to be more satisfied with their dermatologist than did insecure patients. These results suggest that secure attachment of dermatological outpatients may be a protective factor in the management of stress.Peer reviewedFinal Published versio
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