357 research outputs found

    Quantitative variations in the expression of the mouse serum antigen Ss and its sex-limited allotype Slp

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    A radial immunodiffusion assay for quantitation of the Ss and Slp serum antigens is described. Significant differences between the mean serum concentrations of Ss and Slp were found among various inbred strains. Some of these differences have been shown to be associated with the H-2 haplotype. The quantitative difference between Slp levels associated with the H-2 a and H-2 S haplotypes has been used as a marker for the S region in the analysis of certain H-2 recombinant strains [A.TH, B10.S(7R), B10.S(9R), and B10.BSVS]. Male mice of two strains with the H-2 b haplotype have been shown to have significantly lower levels of Ss compared to males of the other strains tested. Male mice of every strain examined were found to have significantly higher levels of Ss in their serum than females of the same strain. The molecular relationship and developmental patterns of the Ss and Slp antigens have also been investigated using the radial immunodiffusion assay.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44121/1/10528_2004_Article_BF00485949.pd

    Analysis of hepatitis C virus RNA dimerization and core–RNA interactions

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    The core protein of hepatitis C virus (HCV) has been shown previously to act as a potent nucleic acid chaperone in vitro, promoting the dimerization of the 3′-untranslated region (3′-UTR) of the HCV genomic RNA, a process probably mediated by a small, highly conserved palindromic RNA motif, named DLS (dimer linkage sequence) [G. Cristofari, R. Ivanyi-Nagy, C. Gabus, S. Boulant, J. P. Lavergne, F. Penin and J. L. Darlix (2004) Nucleic Acids Res., 32, 2623–2631]. To investigate in depth HCV RNA dimerization, we generated a series of point mutations in the DLS region. We find that both the plus-strand 3′-UTR and the complementary minus-strand RNA can dimerize in the presence of core protein, while mutations in the DLS (among them a single point mutation that abolished RNA replication in a HCV subgenomic replicon system) completely abrogate dimerization. Structural probing of plus- and minus-strand RNAs, in their monomeric and dimeric forms, indicate that the DLS is the major if not the sole determinant of UTR RNA dimerization. Furthermore, the N-terminal basic amino acid clusters of core protein were found to be sufficient to induce dimerization, suggesting that they retain full RNA chaperone activity. These findings may have important consequences for understanding the HCV replicative cycle and the genetic variability of the virus

    Using argument notation to engineer biological simulations with increased confidence

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    The application of computational and mathematical modelling to explore the mechanics of biological systems is becoming prevalent. To significantly impact biological research, notably in developing novel therapeutics, it is critical that the model adequately represents the captured system. Confidence in adopting in silico approaches can be improved by applying a structured argumentation approach, alongside model development and results analysis. We propose an approach based on argumentation from safety-critical systems engineering, where a system is subjected to a stringent analysis of compliance against identified criteria. We show its use in examining the biological information upon which a model is based, identifying model strengths, highlighting areas requiring additional biological experimentation and providing documentation to support model publication. We demonstrate our use of structured argumentation in the development of a model of lymphoid tissue formation, specifically Peyer's Patches. The argumentation structure is captured using Artoo (www.york.ac.uk/ycil/software/artoo), our Web-based tool for constructing fitness-for-purpose arguments, using a notation based on the safety-critical goal structuring notation. We show how argumentation helps in making the design and structured analysis of a model transparent, capturing the reasoning behind the inclusion or exclusion of each biological feature and recording assumptions, as well as pointing to evidence supporting model-derived conclusions

    Basement membrane and vascular remodelling in smokers and chronic obstructive pulmonary disease: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Little is known about airway remodelling in bronchial biopsies (BB) in smokers and chronic obstructive pulmonary disease (COPD). We conducted an initial pilot study comparing BB from COPD patients with nonsmoking controls. This pilot study suggested the presence of reticular basement membrane (Rbm) fragmentation and altered vessel distribution in COPD.</p> <p>Methods</p> <p>To determine whether Rbm fragmentation and altered vessel distribution in BB were specific for COPD we designed a cross-sectional study and stained BB from 19 current smokers and 14 ex-smokers with mild to moderate COPD and compared these to 15 current smokers with normal lung function and 17 healthy and nonsmoking subjects.</p> <p>Results</p> <p>Thickness of the Rbm was not significantly different between groups; although in COPD this parameter was quite variable. The Rbm showed fragmentation and splitting in both current smoking groups and ex-smoker COPD compared with healthy nonsmokers (p < 0.02); smoking and COPD seemed to have additive effects. Rbm fragmentation correlated with smoking history in COPD but not with age. There were more vessels in the Rbm and fewer vessels in the lamina propria in current smokers compared to healthy nonsmokers (p < 0.05). The number of vessels staining for vascular endothelial growth factor (VEGF) in the Rbm was higher in both current smoker groups and ex-smoker COPD compared to healthy nonsmokers (p < 0.004). In current smoker COPD VEGF vessel staining correlated with FEV1% predicted (r = 0.61, p < 0.02).</p> <p>Conclusions</p> <p>Airway remodelling in smokers and mild to moderate COPD is associated with fragmentation of the Rbm and altered distribution of vessels in the airway wall. Rbm fragmentation was also present to as great an extent in ex-smokers with COPD. These characteristics may have potential physiological consequences.</p

    The effects of periodontal therapy on serum antibody (IgG) levels to plaque microorganisms *

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    The influence of periodontal therapy on serum antibody titers to selected periodontal disease-associated microorganisms was assessed in 23 patients having chronic inflammatory periodontal disease (CIPD), The immunoglobulin G (IgG) titers were dÉtÉrmined by the micro ELISA technique in serum samples obtained prior to treatment; following a hygienic phase which included scaling, root planing, and oral hygiene instruction; following surgical treatment; and one year and two years following hygienic phase (maintenance phase). Considerable individual variability existed in the magnitude of immune response to specific bacterial preparations. Significant reductions in the mean antibody titers were seen to A. viscosus. S. sanguis. F. nucleatum, S, spuligena, B. gingivalis. B. interme-dius. B. melaninogeniem, T. vincentii , and T denticola by the end of the second year of maintenance. There was no consistent response to Capnucytophaga. When individual patient responses were examined. 6 of the 23 were found to have elevated titers to at least one of the microorganisms in the interval between pretreatment and the end of the hygienic phase; however, in all but one case, the titers at the end of the second year of maintenance were below pretreatment levels. Antibody levels to bacteria such as S. sanguis were modified during therapy. This would indicate that immune responses to microbes not generally considered to be “periodontal pathogens” may be modified by adjuvant activity associated with subgingival plaque or changes in the environment of the sulcus and that subsequent changes in titer do not necessarily reflect a role of that microorganism in the disease process.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75110/1/j.1600-051X.1988.tb02127.x.pd

    Immunodominant PstS1 antigen of mycobacterium tuberculosis is a potent biological response modifier for the treatment of bladder cancer

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    BACKGROUND: Bacillus Calmette Guérin (BCG)-immunotherapy has a well-documented and successful clinical history in the treatment of bladder cancer. However, regularly observed side effects, a certain degree of nonresponders and restriction to superficial cancers remain a major obstacle. Therefore, alternative treatment strategies are intensively being explored. We report a novel approach of using a well defined immunostimulatory component of Mycobacterium tuberculosis for the treatment of bladder cancer. The phosphate transport protein PstS1 which represents the phosphate binding component of a mycobacterial phosphate uptake system is known to be a potent immunostimulatory antigen of M. tuberculosis. This preclinical study was designed to test the potential of recombinant PstS1 to serve as a non-viable and defined immunotherapeutic agent for intravesical bladder cancer therapy. METHODS: Mononuclear cells (PBMCs) were isolated from human peripheral blood and stimulated with PstS1 for seven days. The activation of PBMCs was determined by chromium release assay, IFN-γ ELISA and measurement of lymphocyte proliferation. The potential of PstS1 to activate monocyte-derived human dendritic cells (DC) was determined by flow cytometric analysis of the marker molecules CD83 and CD86 as well as the release of the cytokines TNF-α and IL-12. Survival of presensitized and intravesically treated, tumor-bearing mice was analyzed by Kaplan-Meier curve and log rank test. Local and systemic immune response in PstS1-immunotherapy was investigated by anti-PstS1-specific ELISA, splenocyte proliferation assay and immunohistochemistry. RESULTS: Our in vitro experiments showed that PstS1 is able to stimulate cytotoxicity, IFN-γ release and proliferation of PBMCs. Further investigations showed the potential of PstS1 to activate monocyte-derived human dendritic cells (DC). In vivo studies in an orthotopic murine bladder cancer model demonstrated the therapeutic potential of intravesically applied PstS1. Immunohistochemical analysis and splenocyte restimulation assay revealed that local and systemic immune responses were triggered by intravesical PstS1-immunotherapy. CONCLUSION: Our results demonstrate profound in vitro activation of human immune cells by recombinant PstS1. In addition, intravesical PstS1 immunotherapy induced strong local and systemic immune responses together with substantial anti-tumor activity in a preclinical mouse model. Thus, we have identified recombinant PstS1 antigen as a potent immunotherapeutic drug for cancer therapy

    Big issues for small feet : developmental, biomechanical and clinical narratives on children's footwear

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    The effects of footwear on the development of children's feet has been debated for many years and recent work from the developmental and biomechanical literature has challenged long-held views about footwear and the impact on foot development. This narrative review draws upon existing studies from developmental, biomechanical and clinical literature to explore the effects of footwear on the development of the foot. The emerging findings from this support the need for progress in [children's] footwear science and advance understanding of the interaction between the foot and shoe. Ensuring clear and credible messages inform practice requires a progressive evidence base but this remains big issue in children's footwear research

    Differences in Immunoglobulin Light Chain Species Found in Urinary Exosomes in Light Chain Amyloidosis (AL)

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    Renal involvement is a frequent consequence of plasma cell dyscrasias. The most common entities are light chain amyloidosis, monoclonal immunoglobulin deposition disease and myeloma cast nephropathy. Despite a common origin, each condition has its own unique histologic and pathophysiologic characteristic which requires a renal biopsy to distinguish. Recent studies have shown urinary exosomes containing kidney-derived membrane and cytosolic proteins that can be used to probe the proteomics of the entire urinary system from the glomerulus to the bladder. In this study, we analyzed urine exosomes to determine the differences between exosomes from patients with light chain amyloidosis, multiple myeloma, monoclonal gammopathy of undetermined significance, and non-paraproteinemia related kidney disease controls. In patients with light chain amyloidosis, multiple myeloma and monoclonal gammopathy of undetermined significance, immunoreactive proteins corresponding to monomeric light chains were found in exosomes by western blot. In all of the amyloidosis samples with active disease, high molecular weight immunoreactive species corresponding to a decamer were found which were not found in exosomes from the other diseases or in amyloidosis exosomes from patients in remission. Few or no light chains monomeric bands were found in non-paraproteinemia related kidney disease controls. Our results showed that urinary exosomes may have tremendous potential in furthering our understanding of the pathophysiology and diagnosis of plasma cell dyscrasia related kidney diseases
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