83 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. Β© 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

    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 TLR2βˆ’/βˆ’ 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-Ξ² in kidneys of TLR2βˆ’/βˆ’ mice compared with TLR2+/+ animals. Although, the obstructed kidneys of TLR2βˆ’/βˆ’ 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

    Linear and Branched Glyco-Lipopeptide Vaccines Follow Distinct Cross-Presentation Pathways and Generate Different Magnitudes of Antitumor Immunity

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    Glyco-lipopeptides, a form of lipid-tailed glyco-peptide, are currently under intense investigation as B- and T-cell based vaccine immunotherapy for many cancers. However, the cellular and molecular mechanisms of glyco-lipopeptides (GLPs) immunogenicity and the position of the lipid moiety on immunogenicity and protective efficacy of GLPs remain to be determined.We have constructed two structural analogues of HER-2 glyco-lipopeptide (HER-GLP) by synthesizing a chimeric peptide made of one universal CD4(+) epitope (PADRE) and one HER-2 CD8(+) T-cell epitope (HER(420-429)). The C-terminal end of the resulting CD4-CD8 chimeric peptide was coupled to a tumor carbohydrate B-cell epitope, based on a regioselectively addressable functionalized templates (RAFT), made of four alpha-GalNAc molecules. The resulting HER glyco-peptide (HER-GP) was then linked to a palmitic acid moiety, attached either at the N-terminal end (linear HER-GLP-1) or in the middle between the CD4+ and CD8+ T cell epitopes (branched HER-GLP-2). We have investigated the uptake, processing and cross-presentation pathways of the two HER-GLP vaccine constructs, and assessed whether the position of linkage of the lipid moiety would affect the B- and T-cell immunogenicity and protective efficacy. Immunization of mice revealed that the linear HER-GLP-1 induced a stronger and longer lasting HER(420-429)-specific IFN-gamma producing CD8(+) T cell response, while the branched HER-GLP-2 induced a stronger tumor-specific IgG response. The linear HER-GLP-1 was taken up easily by dendritic cells (DCs), induced stronger DCs maturation and produced a potent TLR- 2-dependent T-cell activation. The linear and branched HER-GLP molecules appeared to follow two different cross-presentation pathways. While regression of established tumors was induced by both linear HER-GLP-1 and branched HER-GLP-2, the inhibition of tumor growth was significantly higher in HER-GLP-1 immunized mice (p<0.005).These findings have important implications for the development of effective GLP based immunotherapeutic strategies against cancers

    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

    Mechanism of cellular rejection in transplantation

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    The explosion of new discoveries in the field of immunology has provided new insights into mechanisms that promote an immune response directed against a transplanted organ. Central to the allograft response are T lymphocytes. This review summarizes the current literature on allorecognition, costimulation, memory T cells, T cell migration, and their role in both acute and chronic graft destruction. An in depth understanding of the cellular mechanisms that result in both acute and chronic allograft rejection will provide new strategies and targeted therapeutics capable of inducing long-lasting, allograft-specific tolerance

    An Analytical Framework to Measure Effective Human Machine Interaction

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