2,697 research outputs found

    Effects of hydroxyapatite and PDGF concentrations on osteoblast growth in a nanohydroxyapatite-polylactic acid composite for guided tissue regeneration

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    The technique of guided tissue regeneration (GTR) has evolved over recent years in an attempt to achieve periodontal tissue regeneration by the use of a barrier membrane. However, there are significant limitations in the currently available membranes and overall outcomes may be limited. A degradable composite material was investigated as a potential GTR membrane material. Polylactic acid (PLA) and nanohydroxyapatite (nHA) composite was analysed, its bioactive potential and suitability as a carrier system for growth factors were assessed. The effect of nHA concentrations and the addition of platelet derived growth factor (PDGF) on osteoblast proliferation and differentiation was investigated. The bioactivity was dependent on the nHA concentration in the films, with more apatite deposited on films containing higher nHA content. Osteoblasts proliferated well on samples containing low nHA content and differentiated on films with higher nHA content. The composite films were able to deliver PDGF and cell proliferation increased on samples that were pre absorbed with the growth factor. nHA–PLA composite films are able to deliver active PDGF. In addition the bioactivity and cell differentiation was higher on films containing more nHA. The use of a nHA–PLA composite material containing a high concentration of nHA may be a useful material for GTR membrane as it will not only act as a barrier, but may also be able to enhance bone regeneration by delivery of biologically active molecules

    Molecular response with blinatumomab in relapsed/refractory B-cell precursor acute lymphoblastic leukemia

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    Minimal residual disease (MRD), where leukemic cell levels are lower than the morphologic detection threshold, is the most important prognostic factor for acute lymphoblastic leukemia (ALL) relapse during first-line chemotherapy treatment and is standard of care in treatment monitoring and decision making. Limited data are available on the prognostic value of MRD response after relapse. We evaluated the relationship between MRD response and outcomes in blinatumomab-treated adults with relapsed/refractory (R/R) B-cell precursor ALL. Of 90 patients with complete remission (CR) or CR with partial hematologic recovery (CRh), 64 (71.1%) achieved a complete MRD response (no detectable individual rearrangements of immunoglobulin/T-cell receptor genes by polymerase chain reaction [PCR] at a minimum sensitivity level of 10-4). Eleven patients had MRD <10-4. Therefore, overall, 75 (83.3%) experienced an MRD response (no detectable MRD or detectable MRD) measured by PCR within the first 2 treatment cycles. Overall survival (OS) and relapse-free survival (RFS) were significantly longer in patients who achieved CR/CRh and MRD response (median, 20.6 and 9.0 months, respectively) compared with CR/CRh patients without MRD response (median, 12.5 and 2.3 months, respectively). In conclusion, longer durations of OS and RFS associated with MRD response support the value of achieving MRD response and its use as a prognostic factor for blinatumomab treatment in R/R ALL. This trial was registered at www.clinicaltrials.gov as #NCT01466179

    Wearable and autonomous computing for future smart cities: open challenges

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    The promise of smart cities offers the potential to change the way we live, and refers to the integration of IoT systems for people-centred applications, together with the collection and processing of data, and associated decision making. Central to the realization of this are wearable and autonomous computing systems. There are considerable challenges that exist in this space that require research across different areas of electronics and computer science; it is this multidisciplinary consideration that is novel to this paper. We consider these challenges from different perspectives, involving research in devices, infrastructure and software. Specifically, the challenges considered are related to IoT systems and networking, autonomous computing, wearable sensors and electronics, and the coordination of collectives comprising human and software agents

    MRI of the lung (3/3)-current applications and future perspectives

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    BACKGROUND: MRI of the lung is recommended in a number of clinical indications. Having a non-radiation alternative is particularly attractive in children and young subjects, or pregnant women. METHODS: Provided there is sufficient expertise, magnetic resonance imaging (MRI) may be considered as the preferential modality in specific clinical conditions such as cystic fibrosis and acute pulmonary embolism, since additional functional information on respiratory mechanics and regional lung perfusion is provided. In other cases, such as tumours and pneumonia in children, lung MRI may be considered an alternative or adjunct to other modalities with at least similar diagnostic value. RESULTS: In interstitial lung disease, the clinical utility of MRI remains to be proven, but it could provide additional information that will be beneficial in research, or at some stage in clinical practice. Customised protocols for chest imaging combine fast breath-hold acquisitions from a "buffet" of sequences. Having introduced details of imaging protocols in previous articles, the aim of this manuscript is to discuss the advantages and limitations of lung MRI in current clinical practice. CONCLUSION: New developments and future perspectives such as motion-compensated imaging with self-navigated sequences or fast Fourier decomposition MRI for non-contrast enhanced ventilation- and perfusion-weighted imaging of the lung are discussed. Main Messages β€’ MRI evolves as a third lung imaging modality, combining morphological and functional information. β€’ It may be considered first choice in cystic fibrosis and pulmonary embolism of young and pregnant patients. β€’ In other cases (tumours, pneumonia in children), it is an alternative or adjunct to X-ray and CT. β€’ In interstitial lung disease, it serves for research, but the clinical value remains to be proven. β€’ New users are advised to make themselves familiar with the particular advantages and limitations

    Cyclin D1, cyclin E, and p21 have no apparent prognostic value in anal carcinomas treated by radiotherapy with or without chemotherapy

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    The purpose of this study was to assess the potential prognostic and/or predictive value of the expression of cyclin D1, cyclin E, and p21 protein in a series of 98 anal carcinomas (T1-4, N0-3) treated by radiotherapy with (51) or without (47) chemotherapy in one institution. Correlation with Mib1 index and p53 expression was also investigated. Median follow-up for surviving patients was 124 months (range: 30-266). Immunohistochemical staining was performed on pretreatment biopsies, applying a standard ABC technique for cyclin D1 (clone DSC6, DAKO, 1 : 300), cyclin E (clone 13A3, Novocastra, 1 : 100), p21(WAF/CIP1) (clone SX118, DAKO, 1 : 50), p53 (clone DO7, DAKO, 1 : 200), and Mib1 (Ki-67, Dianova, 1 : 20). Tumours were classified into low- or high-expression groups according to the expression level of the protein considered. High expression was found in 51% of tumours for cyclin E, in 33.7% for cyclin D1, and in 65% for p21. None of those factors were significantly associated with clinical variables such as advanced T or N categories. In a monovariate analysis, advanced T and N categories and longer overall treatment time were the only variables that correlated significantly with low rate of local control (LC) and disease-free survival. However, in a subgroup analysis, high p21 expression correlated with a trend for significantly higher 5-year LC (87 vs 68%, P=0.07) in the N0 patients. The results of this study suggest that the cell-cycle proteins investigated are unlikely to be clinically useful in predicting treatment response or prognosis in patients with anal carcinomas

    Auditory grouping occurs prior to intersensory pairing: evidence from temporal ventriloquism

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    The authors examined how principles of auditory grouping relate to intersensory pairing. Two sounds that normally enhance sensitivity on a visual temporal order judgement task (i.e. temporal ventriloquism) were embedded in a sequence of flanker sounds which either had the same or different frequency (Exp. 1), rhythm (Exp. 2), or location (Exp. 3). In all experiments, we found that temporal ventriloquism only occurred when the two capture sounds differed from the flankers, demonstrating that grouping of the sounds in the auditory stream took priority over intersensory pairing. By combining principles of auditory grouping with intersensory pairing, we demonstrate that capture sounds were, counter-intuitively, more effective when their locations differed from that of the lights rather than when they came from the same position as the lights

    Non-invasive measurements of atherosclerosis in adult cystinosis patients

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    Item does not contain fulltextBACKGROUND: Cystinosis is characterized by intralysosomal cystine accumulation, causing end stage renal disease around 10 years of age if not treated with cysteamine. Cystine accumulation in blood vessels might increase atheroma formation or arterial stiffness and therefore increase the risk for cardiovascular disease (CVD). This study aimed to investigate the risk for CVD by non-invasive measures of atherosclerosis (NIMA) and to evaluate the effect of cysteamine treatment. PATIENTS AND METHODS: Thirteen Dutch adult cystinosis patients were included. White blood cell (WBC) cystine levels, glomerular filtration rate (GFR) and concommitant medications were obtained from medical records. NIMA included carotid intima-media thickness (cIMT, n = 13), pulse wave velocity (PWV, n = 8) and pulse wave analysis (PWA, n = 6). Results : GFR ranged between 4-95 mL/min/1.73 m(2). All but one patient were treated with cysteamine, mean WBC cystine values ranged between 0.34-1.64 nmol cystine/mg protein, 8 patients had mean WBC cystine levels <1 nmol cystine/mg protein. When compared to healthy subjects, cIMT and PWV levels were above normal values in 1 patient for each measure. PWA measurements showed high augmentation index in three patients who did not receive lipid-lowering medication. When corrected for renal function, cIMT and PWV levels were within the normal range. CONCLUSION: Young adult cystinosis patients treated with cysteamine have no additional risk for CVD when compared to patients with chronic kidney disease of other causes

    A four-helix bundle stores copper for methane oxidation

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    Methane-oxidising bacteria (methanotrophs) require large quantities of copper for the membrane-bound (particulate) methane monooxygenase (pMMO). Certain methanotrophs are also able to switch to using the iron-containing soluble MMO (sMMO) to catalyse methane oxidation, with this switchover regulated by copper. MMOs are Nature’s primary biological mechanism for suppressing atmospheric levels of methane, a potent greenhouse gas. Furthermore, methanotrophs and MMOs have enormous potential in bioremediation and for biotransformations producing bulk and fine chemicals, and in bioenergy, particularly considering increased methane availability from renewable sources and hydraulic fracturing of shale rock. We have discovered and characterised a novel copper storage protein (Csp1) from the methanotroph Methylosinus trichosporium OB3b that is exported from the cytosol, and stores copper for pMMO. Csp1 is a tetramer of 4-helix bundles with each monomer binding up to 13 Cu(I) ions in a previously unseen manner via mainly Cys residues that point into the core of the bundle. Csp1 is the first example of a protein that stores a metal within an established protein-folding motif. This work provides a detailed insight into how methanotrophs accumulate copper for the oxidation of methane. Understanding this process is essential if the wide-ranging biotechnological applications of methanotrophs are to be realised. Cytosolic homologues of Csp1 are present in diverse bacteria thus challenging the dogma that such organisms do not use copper in this location

    Effects of Ferumoxides – Protamine Sulfate Labeling on Immunomodulatory Characteristics of Macrophage-like THP-1 Cells

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    Superparamagnetic Iron Oxide (SPIO) complexed with cationic transfection agent is used to label various mammalian cells. Labeled cells can then be utilized as an in vivo magnetic resonance imaging (MRI) probes. However, certain number of in vivo administered labeled cells may be cleared from tissues by the host's macrophages. For successful translation to routine clinical application of SPIO labeling method it is important that this mode of in vivo clearance of iron does not elicit any diverse immunological effects. The purpose of this study was to demonstrate that SPIO agent ferumoxides-protamine sulfate (FePro) incorporation into macrophages does not alter immunological properties of these cells with regard to differentiation, chemotaxis, and ability to respond to the activation stimuli and to modulate T cell response. We used THP-1 cell line as a model for studying macrophage cell type. THP-1 cells were magnetically labeled with FePro, differentiated with 100 nM of phorbol ester, 12-Myristate-13-acetate (TPA) and stimulated with 100 ng/ml of LPS. The results showed 1) FePro labeling had no effect on the changes in morphology and expression of cell surface proteins associated with TPA induced differentiation; 2) FePro labeled cells responded to LPS with slightly higher levels of NFΞΊB pathway activation, as shown by immunobloting; TNF-Ξ± secretion and cell surface expression levels of CD54 and CD83 activation markers, under these conditions, were still comparable to the levels observed in non-labeled cells; 3) FePro labeling exhibited differential, chemokine dependent, effect on THP-1 chemotaxis with a decrease in cell directional migration to MCP-1; 4) FePro labeling did not affect the ability of THP-1 cells to down-regulate T cell expression of CD4 and CD8 and to induce T cell proliferation. Our study demonstrated that intracellular incorporation of FePro complexes does not alter overall immunological properties of THP-1 cells. The described experiments provide the model for studying the effects of in vivo clearance of iron particles via incorporation into the host's macrophages that may follow after in vivo application of any type of magnetically labeled mammalian cells. To better mimic the complex in vivo scenario, this model may be further exploited by introducing additional cellular and biological, immunologically relevant, components
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