217 research outputs found

    Dual-wedge scanning confocal reflectance microscope

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    A confocal reflectance microscope has been developed that incorporates a dual-wedge scanner to reduce the size of the device relative to current raster scanning instruments. The scanner is implemented with two prisms that are rotated about the optical axis. Spiral and rosette scans are performed by rotating the prisms in the same or opposite directions, respectively. Experimental measurements show an on-axis lateral resolution of 1.6 m and optical sectioning of 4.7 m, which compares with a diffraction-limited resolution of 0.8 and 1.9 m, respectively. © 2007 Optical Society of America OCIS codes: 110.0180, 120.3890, 120.4570, 170.1790, 180.1790 Current point-scanning microscopes generally use a raster scan, which is uniform throughout the field-ofview. However, this standard scan requires an optoelectromechanical configuration that is bulky and difficult to reduce to a handheld device. In this Letter, we discuss the implementation of a dual-wedge scanner as an alternative method to scan the focused spot within a confocal reflectance microscope. This scanner uses two prisms within a compact package to provide a circular two-dimensional scan that is capable of high speeds with a nonuniform pixel density, but requires a detailed mapping algorithm to determine the exact location of the spot. The use of two prisms to scan a laser beam was first described by Rosell in 1960 as a prism scanner The concept of the scanner is shown i

    Exploring the impact of a flexible, technology-enhanced teaching space on pedagogy

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    Approaches to teaching and learning are increasingly influenced by the introduction of new technologies and innovative use of space. Recognising the need to keep up to date many institutions has created technology-rich, flexible spaces. Studies so far have concentrated on how students use such facilities; however, their availability also strongly impacts on teaching staff, presenting new possibilities and challenges. To encourage the development of activities that make the most of these resources, the University of Warwick launched the Teaching Grid (2008), a flexible space with state-of-the-art technology. Advisers support colleagues in developing and delivering novel, experimental teaching sessions. This paper reports on use of the facility during its first three years, considering the effects on pedagogy of experimental use of space and technology; this is correlated to an increase in number and variety of teaching and learning activities which, it is suggested, enhances the student experience

    Trace Levels of Innate Immune Response Modulating Impurities (IIRMIs) Synergize to Break Tolerance to Therapeutic Proteins

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    Therapeutic proteins such as monoclonal antibodies, replacement enzymes and toxins have significantly improved the therapeutic options for multiple diseases, including cancer and inflammatory diseases as well as enzyme deficiencies and inborn errors of metabolism. However, immune responses to these products are frequent and can seriously impact their safety and efficacy. Of the many factors that can impact protein immunogenicity, this study focuses on the role of innate immune response modulating impurities (IIRMIs) that could be present despite product purification and whether these impurities can synergize to facilitate an immunogenic response to therapeutic proteins. Using lipopolysaccharide (LPS) and CpG ODN as IIRMIs we showed that trace levels of these impurities synergized to induce IgM, IFNγ, TNFα and IL-6 expression. In vivo, trace levels of these impurities synergized to increase antigen-specific IgG antibodies to ovalbumin. Further, whereas mice treated with human erythropoietin showed a transient increase in hematocrit, those that received human erythropoietin containing low levels of IIRMIs had reduced response to erythropoietin after the 1st dose and developed long-lasting anemia following subsequent doses. This suggests that the presence of IIRMIs facilitated a breach in tolerance to the endogenous mouse erythropoietin. Overall, these studies indicate that the risk of enhancing immunogenicity should be considered when establishing acceptance limits of IIRMIs for therapeutic proteins

    The Role of Toll-Like Receptor 2 in Inflammation and Fibrosis during Progressive Renal Injury

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    Tissue fibrosis and chronic inflammation are common causes of progressive organ damage, including progressive renal disease, leading to loss of physiological functions. Recently, it was shown that Toll-like receptor 2 (TLR2) is expressed in the kidney and activated by endogenous danger signals. The expression and function of TLR2 during renal fibrosis and chronic inflammation has however not yet been elucidated. Therefore, we studied TLR2 expression in human and murine progressive renal diseases and explored its role by inducing obstructive nephropathy in TLR2−/− or TLR2+/+ mice. We found that TLR2 is markedly upregulated on tubular and tubulointerstitial cells in patients with chronic renal injury. In mice with obstructive nephropathy, renal injury was associated with a marked upregulation and change in distribution of TLR2 and upregulation of murine TLR2 danger ligands Gp96, biglycan, and HMGB1. Notably, TLR2 enhanced inflammation as reflected by a significantly reduced influx of neutrophils and production of chemokines and TGF-β in kidneys of TLR2−/− mice compared with TLR2+/+ animals. Although, the obstructed kidneys of TLR2−/− mice had less interstitial myofibroblasts in the later phase of obstructive nephropathy, tubular injury and renal matrix accumulation was similar in both mouse strains. Together, these data demonstrate that TLR2 can initiate renal inflammation during progressive renal injury and that the absence of TLR2 does not affect the development of chronic renal injury and fibrosis

    Transcutaneous immunization as preventative and therapeutic regimens to protect against experimental otitis media due to nontypeable Haemophilus influenzae

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    We have developed three nontypeable Haemophilus influenzae (NTHI) adhesin-derived immunogens that are significantly efficacious against experimental otitis media (OM) due to NTHI when delivered parenterally. We now expanded our preventative immunization strategies to include transcutaneous immunization (TCI) as a less invasive, but potentially equally efficacious, regimen to prevent OM due to NTHI. Additionally, we examined the potential of TCI as a therapeutic immunization regimen to resolve ongoing experimental OM. Preventative immunization with NTHI outer membrane protein (OMP) P5- and type IV pilus-targeted immunogens, delivered with the adjuvant LT(R192G-L211A), induced significantly earlier clearance of NTHI from the nasopharynges and middle ears of challenged chinchillas compared with receipt of immunogen or adjuvant alone. Moreover, therapeutic immunization resulted in significant resolution of established NTHI biofilms from the middle ear space of animals compared with controls. These data advocate TCI with the adhesin-directed immunogens as an efficacious regimen for prevention and resolution of experimental NTHI-induced OM
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