118 research outputs found
Properties of -normal operators (Research on preserver problems on Banach algebras and related topics)
We study various properties of -normal operators, i.e., = holds for a conjugation on . Especially, we show that − λ is -normal for all λ ∈ ℂ if and only if is a complex symmetric operator with the conjugation . In addition, we prove that if is -normal, then is normal ⇔ is quasinormal ⇔ is hyponormal ⇔ is -hyponormal for 0 < ≤ 1. Finally, we investigate equivalent conditions so that Aluthge and Duggal transforms of -normal operators to be -normal operators
Commonly Used Anesthesia/Euthanasia Methods for Brain Collection Differentially Impact MAPK Activity in Male and Female C57BL/6 Mice
The mitogen-activated protein kinases (MAPKs) are a family of protein kinases that regulate crucial neuronal functions such as neuronal differentiation, proliferation, and apoptosis through phosphorylation of subsequent protein kinases. The three classical MAPK subfamilies, extracellular signal-regulated kinase 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 kinase have been linked to various neurological disorders often in conjunction with activation of a wide range of G protein-coupled receptors and receptor tyrosine kinases. Many studies investigating MAPK function in these disorders rely on histochemistry or immunoblotting that require brain isolation following euthanasia. Here, we evaluated to what degree different modes of anesthesia/euthanasia impact MAPK activity in adult male and female C57BL/6 mice. Mice were decapitated following ketamine/xylazine or isoflurane anesthesia, carbon dioxide asphyxiation, or without anesthesia. We selectively chose five brain regions (the prefrontal cortex, the dorsal hippocampus, the dorsal striatum, the nucleus accumbens, and the amygdala) that are heavily implicated in neuropsychiatric disorders. We found that relative to carbon dioxide asphyxiation, the other methods displayed significantly stronger ERK1/2 phosphorylation in select brain regions of male and female mice, with no pronounced sex difference. A similar, yet, less pronounced trend was observed for JNK activity, whereas the choice of euthanasia method did not differentially impact p38 phosphorylation. Our study results reveal how small differences in experimental design may impact whether one will be able to detect drug- or disease-related changes in MAPK activity. These findings are timely in a period where experimental rigor is emphasized to increase reproducibility of research
Mesenchymal stem/stromal cells precondition lung monocytes/macrophages to produce tolerance against allo- and autoimmunity in the eye
Intravenously administered mesenchymal stem/stromal cells (MSCs) engraft only transiently in recipients, but confer long-term therapeutic benefits in patients with immune disorders. This suggests that MSCs induce immune tolerance by long-lasting effects on the recipient immune regulatory system. Here, we demonstrate that i.v. infusion of MSCs preconditioned lung monocytes/macrophages toward an immune regulatory phenotype in a TNF-α–stimulated gene/protein (TSG)-6–dependent manner. As a result, mice were protected against subsequent immune challenge in two models of allo- and autoimmune ocular inflammation: corneal allotransplantation and experimental autoimmune uveitis (EAU). The monocytes/macrophages primed by MSCs expressed high levels of MHC class II, B220, CD11b, and IL-10, and exhibited T-cell–suppressive activities independently of FoxP3(+) regulatory T cells. Adoptive transfer of MSC-induced B220(+)CD11b(+) monocytes/macrophages prevented corneal allograft rejection and EAU. Deletion of monocytes/macrophages abrogated the MSC-induced tolerance. However, MSCs with TSG-6 knockdown did not induce MHC II(+)B220(+)CD11b(+) cells, and failed to attenuate EAU. Therefore, the results demonstrate a mechanism of the MSC-mediated immune modulation through induction of innate immune tolerance that involves monocytes/macrophages
The Efficacy of an Acrylic Intraocular Lens Surface Modified with Polyethylene Glycol in Posterior Capsular Opacification
To investigate if the surface modification of intraocular lens (IOL) is efficient in the prevention of posterior capsular opacification (PCO), the acrylic surface of intraocular lens (Acrysof®) was polymerized with polyethylene glycol (PEG-IOL). The human lens epithelial cells (1×104 cells/mL) were inoculated on PEG grafted or unmodified acrylic lenses for the control. The adherent cells on each IOL surface were trypsinized and counted. The every PEG-IOL was implanted in 20 New Zealand rabbits after removal of crystalline lens. The formations of PCO were checked serially through retroilluminated digital photography, and the severity scores were calculated using POCOman®. The cell adherence patterns on each IOL were examined by scanning electron microscopy. As a result, the mean number of adherent cells of PEG-IOL (3.2±1.1×103) tended to be smaller than that of the acrylic controls (3.6±1.9×103) without a statistical significance (p=0.73). However, the mean severity of PCO formation in PEG-IOL was significantly lower than that in the control during the third to sixth weeks after surgery. Scanning electron microscopy revealed that the more patch-like cells were found firmly attached to the IOL surface in control than in the PEG-IOL. Conclusively, PEG polymerization to the acrylic IOL would possibly lessen the formation of PCO after cataract removal
Investigating the Relationship between Serum Interleukin-17 Levels and Systemic Immune-Mediated Disease in Patients with Dry Eye Syndrome
Purpose: To investigate the association between dry eye syndrome (DE) and serum levels of interleukin (IL)-17 in patients with systemic immune-mediated diseases. Methods: IL-17 and IL-23 levels were measured in the sera of patients whose tear production was <5 mm on the Schirmer test. Subjects included patients with chronic graft-versus-host disease (GVHD), rheumatoid arthritis (RA), Sjogren’s syndrome (SS), systemic lupus erythematosus (SLE), and no systemic disease. Corneal/conjunctival fluorescein staining was scored and the correlation between the score and the IL-17 level was evaluated. Results: A strong correlation existed between IL-17 level and the type of systemic disease. IL-17 was significantly elevated in patients with chronic GVHD compared to those with RA and SS. IL-17 was not detectable in patients with SLE or in those without systemic disease. IL-23 was not detected in any of the subjects. IL-17 was significantly increased in patients with high fluorescein staining scores. Conclusions: Our data suggest that IL-17 is involved in the pathogenesis of DE in patients with systemic immune-mediated diseases. Key Words: Chronic graft-versus-host disease, Dry eye syndromes, Interleukin-17, Rheumatoid arthritis, Sjogren’s syndrom
The Role of Cyclosporine and Mycophenolate in an Orthotopic Porcine-to-Rat Corneal Xenotransplantation
We performed this study to investigate the feature of rejection in porcine-to-rat corneal orthotopic transplantation and to evaluate the effect of cyclosporine and mycophenolate on the xeno-rejection. Orthotopic corneal transplantation was done at 91 Sprague-Dawley rats, and they were divided into 10 groups based on the combination of immunosuppressants including dexamethasone, cyclosporine, and mycophenolate mofetil. Graft survival was analyzed and grafted eyes were examined with Hematoxylin & Eosin and CD4 or CD8 staining. Enzyme-linked immunosorbent assays were done for interleukin-2 (IL-2), IL-4, IL-5, IL-10, and interferon (IFN)-γ in cornea, lacrimal gland, and cervical lymph nodes. The longest median survival of the immune suppressant group was 11.00±1.96 days, which showed no statistical differences compared with that of control (8.00±1.52 days). The neutrophils were prominent in the early phase but soon gave way to the monocytes. The number of CD8+ cells was higher than that of CD4+ cells. IL-2 and IFN-γ markedly increased at 10 to13 days in cornea, lacrimal glands, and cervical lymph nodes, which showed a decrease with immunosuppressants except in the cornea. In conclusion, cyclosporine and mycophenolate could not prevent the rejection in porcine to rat orthotopic corneal xenograft associated with infiltraton of CD8+ and innate immune cells
DNA Microarray-Based Gene Expression Profiling in Porcine Keratocytes and Corneal Endothelial Cells and Comparative Analysis Associated with Xeno-related Rejection
Porcine to rat corneal xenotransplantation resulted in severe inflammation and rejection of the corneal stroma, whereas an allograft showed mainly endothelial cell-associated rejection. We, therefore, investigated and compared the gene expression between porcine keratocytes and corneal endothelial cells. RNA was isolated from primary cultured porcine or human keratocytes and porcine corneal endothelial cells. Gene expression was comparatively analyzed after normalization with microarray method using Platinum pig 13 K oligo chip (GenoCheck Co., Ltd., Ansan, Korea). Real-time polymerase chain reaction (PCR) was performed for C1R, CCL2, CXCL6, and HLA-A in porcine keratocytes and corneal endothelial cells. As a result, upregulated expression more than 2 folds was observed in 1,162 genes of porcine keratocytes versus porcine endothelial cells. Among the immune-regulatory genes, SEMA3C, CCL2, CXCL6, F3, HLA-A, CD97, IFI30, C1R, and G1P3 were highly expressed in porcine keratocytes, compared to porcine corneal endothelial cells or human keratocytes. When measured by real-time PCR, the expression of C1R, CCL2, and HLA-A was higher in porcine keratocytes compared to that in porcine corneal endothelial cells. In conclusion, the increased expression of C1R, CCL2, and HLA-A genes in porcine keratocytes might be responsible for the stromal rejection observed in a porcine to rat corneal xenotransplantation
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