194 research outputs found

    Giant nonlinear optical effects induced by nitrogen-vacancy centers in diamond crystals

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    We investigate the effect of nitrogen-vacancy (NV) centers in single crystal diamond on nonlinear optical effects using 40 fs femtosecond laser pulses. The near-infrared femtosecond pulses allow us to study purely nonlinear optical effects, such as optical Kerr effect (OKE) and two-photon absorption (TPA), related to unique optical transitions by electronic structures with NV centers. It is found that both nonlinear optical effects are enhanced by the introduction of NV centers in the N+ dose levels of 2.0×1011 and 1.0×1012 N+/cm2. In particular, our data demonstrate that the OKE signal is strongly enhanced for the heavily implanted type-IIa diamond. We suggest that the strong enhancement of the OKE is possibly originated from cascading OKE, where the high-density NV centers effectively break the inversion symmetry near the surface region of diamond

    CD4 T cells but not Th17 cells are Required for Mouse Lung Transplant Obliterative Bronchiolitis

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    Lung transplant survival is limited by obliterative bronchiolitis (OB), but the mechanisms of OB development are unknown. Previous studies in a mouse model of orthotopic lung transplantation suggested a requirement for IL-17. We have used this orthotopic mouse model to investigate the source of IL-17A and the requirement for T cells producing IL-17A. The major sources of IL-17A were CD4+ T cells and γδ T cells. Depletion of CD4+ T cells led to a significantly decreased frequency and number of IL-17A+ lymphocytes and was sufficient to prevent acute rejection and OB. However, mice with STAT3-deficient T cells, which are unable to differentiate into Th17 cells, rejected lung allografts and developed OB similar to control mice. The frequency of IL-17A+ cells was not decreased in mice with STAT3-deficient T cells due mainly to the presence of IL-17A+ γδ T cells. Deficiency of γδ T cells also did not affect the development of airway fibrosis. Our data suggest that CD4+ T cells are required for OB development and expansion of IL-17A responses in the lung, while Th17 and γδ T cells are not absolutely required and may compensate for each other

    Targeting PD-1/PD-L1 inhibits rejection in a heterotopic tracheal allograft model of lung transplantation

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    Immune checkpoint molecules such as programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) have revolutionized the field of lung cancer treatment. As part of our study, we examined the role of these proteins in acute rejection in a mouse model of heterotopic tracheal transplantation. Recipient mice were untreated (Allo group) or treated with anti-PD-L1 (aPDL1 group) or PD-L1 Fc recombinant protein (PD-L1 Fc group). A further group of C57BL/6 mice received isografts (Iso group). The occlusion rate was significantly higher in the Allo group than in the Iso group (p = 0.0075), and also higher in the aPD-L1 group (p = 0.0066) and lower in the PD-L1 Fc group (p = 0.030) than in the Allo group. PD-L1 Fc recombinant protein treatment significantly decreased interleukin-6 and interferon-γ levels and reduced the CD4+/CD8+ T cell ratio, without increasing PD-1 and T-cell immunoglobulin mucin 3 expression in CD4+ T cells. These data suggest that PD-L1 Fc recombinant protein decreases the levels of inflammatory cytokines and the proportion of CD4+ T cells without exhaustion. The PD-L1-mediated immune checkpoint mechanism was associated with rejection in the murine tracheal transplant model, suggesting a potential novel target for immunotherapy in lung transplantation

    Cerebral air embolism as a complication of peptic ulcer in the gastric tube: case report

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    <p>Abstract</p> <p>Background</p> <p>The reported incidence of ulcer formation in the gastric tube in esophageal replacement is rare.</p> <p>Case Presentation</p> <p>This is the first report of a case of cerebral air embolism as a result of spontaneous perforation of an ulcer in the constructed gastric tube into the pulmonary vein during post-operative follow-up in a patient with esophageal cancer.</p> <p>Conclusions</p> <p>Cerebral air embolism is a rare complication of penetrating gastric ulcer, but should be considered in patients with a history of esophagectomy with gastric conduit that present with acute neurologic findings.</p

    Clinical Study Frequency of Adverse Events of Antithyroid Drugs Administered during Pregnancy

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    The frequency and types of adverse events after initial antithyroid drug (ATD) therapy during pregnancy have never been reported, nor has whether the frequency of adverse events is the same as among nonpregnant subjects ever been investigated. We investigated retrospectively the frequency of adverse events after initial ATD administration to previously untreated Graves&apos; disease (GD) patients during pregnancy. We reviewed the charts of cases of 91 untreated pregnant women who came to our hospital for the first time and were newly diagnosed with GD during the period between January 1, 1999, and December 31, 2011. Thiamazole (MMI) was used to treat 40 patients and 51 patients were treated with propylthiouracil (PTU). Adverse events occurred in 5 patients (5/40; 12.5%) treated with MMI, and they consisted of cutaneous reactions in 5 patients. Adverse events occurred in five patients (5/51; 9.8%) treated with PTU, and they consisted of hepatotoxicity in two patients and cutaneous reactions in three patients. No patients experienced agranulocytosis or ANCA-related vasculitis. Comparison with the expected rate of adverse events in nonpregnant individuals showed that the frequency of adverse events in pregnant individuals was low

    Role of Complement Activation in Obliterative Bronchiolitis Post Lung Transplantation

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    Obliterative bronchiolitis (OB) post lung transplantation involves IL-17 regulated autoimmunity to type V collagen and alloimmunity, which could be enhanced by complement activation. However, the specific role of complement activation in lung allograft pathology, IL-17 production, and OB are unknown. The current study examines the role of complement activation in OB. Complement regulatory protein (CRP) (CD55, CD46, Crry/CD46) expression was down regulated in human and murine OB; and C3a, a marker of complement activation, was up regulated locally. IL-17 differentially suppressed Crry expression in airway epithelial cells in vitro. Neutralizing IL-17 recovered CRP expression in murine lung allografts and decreased local C3a production. Exogenous C3a enhanced IL-17 production from alloantigen or autoantigen (type V collagen) reactive lymphocytes. Systemically neutralizing C5 abrogated the development of OB, reduced acute rejection severity, lowered systemic and local levels of C3a and C5a, recovered CRP expression, and diminished systemic IL-17 and IL-6 levels. These data indicated that OB induction is in part complement dependent due to IL-17 mediated down regulation of CRPs on airway epithelium. C3a and IL-17 are part of a feed forward loop that may enhance CRP down regulation, suggesting that complement blockade could be a therapeutic strategy for OB
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