374 research outputs found

    Creating a Sustainable Environment to Preserve Access to Humanities, Innovation, and STEM Education Collections at WPI

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    Worcester Polytechnic Institute's George C. Gordon Library seeks an implementation grant to fund the partial renovation of the existing Special Collections Wing to provide adequate environmental conditions and fire protection for the storage and preservation of archival and special collections materials

    (2E,4E)-1-(6-Chloro-2-methyl-4-phenyl-3-quinol­yl)-5-phenyl­penta-2,4-dien-1-one

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    In the title compound, C27H20ClNO, the quinoline ring forms a dihedral angle of 62.53 (5)° with the substituent benzene ring. In the crystal, inter­molecular C—H⋯Cl inter­actions link the mol­ecules into chains along the b axis. Inter­molecular C—H⋯N and C—H⋯O hydrogen bonds further consolidate the structure into a three-dimensional network. The unit cell contains four solvent-accessible voids, each with a volume of 35 Å3, but no significant electron density was found in them

    2-Bromo­ethyl 2-chloro-6-methyl­quinoline-3-carboxyl­ate

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    In the title compound, C13H11BrClNO2, the two rings of the quinoline group are fused in an axial fashion at a dihedral angle of 1.28 (9)°. In the crystal, molecules are arranged in zigzag layers along the c axis. The crystal packing is stabilized by weak C—H⋯O hydrogen bonds and inter­molecular inter­actions between Br and O atoms [Br⋯O= 3.076 (2) Å], resulting in the formation of a three-dimensional network

    1-(6-Chloro-2-methyl-4-phenyl­quinolin-3-yl)-3-(3-methoxy­phen­yl)prop-2-en-1-one

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    In the title compound, C26H20ClNO2, the quinoline ring system is approximately planar with a maximum deviation of 0.028 (2) Å and forms a dihedral angle of 73.84 (5)° with the phenyl ring. Two neighbouring mol­ecules are arranged into a centrosymmetric dimer through a pair of inter­molecular C—H⋯Cl inter­actions. A pair of inter­molecular C—H⋯O hydrogen bonds link two methoxy­phenyl groups into another centrosymmetric dimer, generating an R 2 2(8) ring motif. The structure is further stabilized by C—H⋯π inter­actions

    Rapid quantification of naive alloreactive T cells by TNF-alpha production and correlation with allograft rejection in mice

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    Allograft transplantation requires chronic immunosuppression, but there is no effective strategy to evaluate the long-term maintenance of immunosuppression other than assessment of graft function. The ability to monitor naive alloreactive T cells would provide an alternative guide for drug therapy at early, preclinical stages of graft rejection and for evaluating tolerance-inducing protocols. To detect and quantify naive alloreactive T cells directly ex vivo, we used the unique ability of naive T cells to rapidly produce TNF-alpha but not IFN-gamma. Naive alloreactive T cells were identified by the production of TNF-alpha after a 5-hour in vitro stimulation with alloantigen and were distinguished from effector/memory alloreactive T cells by the inability to produce IFN-gamma. Moreover, naive alloreactive T cells were not detected in mice tolerized against specific alloantigens. The frequency of TNF-alpha-producing cells was predictive for rejection in an in vivo cytotoxicity assay and correlated with skin allograft rejection. Naive alloreactive T cells were also detected in humans, suggesting clinical relevance. We conclude that rapid production of TNF-alpha can be used to quantify naive alloreactive T cells, that it is abrogated after the induction of tolerance, and that it is a potential tool to predict allograft rejection

    (E)-1-(6-Chloro-2-methyl-4-phenyl-3-quinol­yl)-3-(2-methoxy­phen­yl)prop-2-en-1-one

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    In the title compound, C26H20ClNO2, the quinoline ring system and the methoxy­phenyl ring form dihedral angles of 69.97 (6) and 22.10 (10)°, respectively, with the propenone linkage. The 4-phenyl ring substituent on the quinoline ring system is oriented at a dihedral angle of 66.47 (3)°. In the crystal, mol­ecules exist as C—H⋯O hydrogen-bonded dimers. The structure is further stabilized by C—H⋯π inter­actions

    (2E)-3-(4-Chloro­phen­yl)-1-(2,4-dimethyl­quinolin-3-yl)prop-2-en-1-one

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    Two independent mol­ecules comprise the asymmetric unit of the title compound, C20H16ClNO, which differ in the orientation of the chalcone residue with respect to the quinoline ring [the C—C—C(=O)—C torsion angles are 69.5 (2) and 86.0 (2)°]. The configuration about each of the ethyl­ene bonds [1.342 (2) and 1.338 (2) Å] is E. The three-dimensional crystal structure is stabilized by a combination of C—H⋯O, C—H⋯N, C—H⋯π inter­actions and π–π contacts between the independent mol­ecules [Cg(C6 of quinoline)⋯Cg(C6 of quinoline) = 3.6719 (11) Å]

    3-Acetyl-6-chloro-2-methyl-4-phenyl­quinolinium perchlorate

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    In the title mol­ecular salt, C18H15ClNO+·ClO4 −, the quinolin­ium ring system is approximately planar, with a maximum deviation of 0.027 (1) Å. The dihedral angle formed between the mean planes of the quinolinium ring system and the benzene ring is 78.46 (3)°. In the crystal structure, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds link the cations and anions into a three-dimensional network. The crystal structure is further consolidated by C—H⋯π inter­actions

    Increased apoptosis of immunoreactive host cells and augmented donor leukocyte chimerism, not sustained inhibition of B7 molecule expression are associated with prolonged cardiac allograft survival in mice preconditioned with immature donor dendritic cells plus anti-CD40L mAb

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    Background. We previously reported the association among donor leukocyte chimerism, apoptosis of presumedly IL-2-deficient graft-infiltrating host cells, and the spontaneous donor-specific tolerance induced by liver but not heart allografts in mice. Survival of the rejection-prone heart allografts in the same strain combination is modestly prolonged by the pretransplant infusion of immature, costimulatory molecule-(CM) deficient donor dendritic cells (DC), an effect that is markedly potentiated by concomitant CM blockade with anti-CD40L (CD154) monoclonal antibody (mAb). We investigated whether the long survival of the heart allografts in the pretreated mice was associated with donor leukocyte chimerism and apoptosis of graft-infiltrating cells, if these end points were similar to those in the spontaneously tolerant liver transplant model, and whether the pretreatment effect was dependent on sustained inhibition of CM expression of the infused immature donor DC. In addition, apoptosis was assessed in the host spleen and lymph nodes, a critical determination not reported in previous studies of either spontaneous or 'treatment-aided' organ tolerance models. Methods. Seven days before transplantation of hearts from B10 (H-2b) donors, 2 x 106 donor- derived immature DC were infused i.v. into C3H (H-2(k)) recipient mice with or without a concomitant i.p. injection of anti-CD40L mAb. Donor cells were detected posttransplantation by immunohistochemical staining for major histocompatibility complex class II (I-Ab) in the cells of recipient lymphoid tissue. CM expression was determined by two-color labeling. Host responses to donor alloantigen were quantified by mixed leukocyte reaction, and cytotoxic T lymphocyte (CTL) assays. Apoptotic death in graft- infiltrating cells and in areas of T-dependent lymphoid tissue was visualized by terminal deoxynucleotidyltransferase-catalyzed dUTP-digoxigenin nick-end labeling and quantitative spectrofluorometry. Interleukin-2 production and localization were estimated by immunohistochemistry. Results. Compared with control heart transplantation or heart transplantation after only DC administration, concomitant pretreatment with immature donor DC and anti- CD40L mAb caused sustained elevation of donor (I-Ab+) cells (microchimerism) in the spleen including T cell areas. More than 80% of the I-Ab+ cells in combined treatment animals also were CD86+, reflecting failure of the mAb to inhibit CD40/CD80/CD86 up-regulation on immature DC in vitro after their interaction with host T cells. Donor-specific CTL activity in graft-infiltrating cells and spleen cell populations of these animals was present on day 8, but decreased strikingly to normal control levels by day 14. The decrease was associated with enhanced apoptosis of graft-infiltrating cells and of cells in the spleen where interleukin-2 production was inhibited. The highest levels of splenic microchimerism were found in mice with long surviving grafts (> 100 days). In contrast, CTL activity was persistently elevated in control heart graft recipients with comparatively low levels of apoptotic activity and high levels of interleukin-2. Conclusion. The donor-specific acceptance of rejection-prone heart allografts by recipients pretreated with immature donor DC and anti-CD40L mAb is not dependent on sustained inhibition of donor DC CM (CD86) expression. Instead, the pretreatment facilitates a tolerogenic cascade similar to that in spontaneously tolerant liver recipients that involves: (1) chimerism-driven immune activation, succeeded by deletion of host immune responder cells by apoptosis in the spleen and allograft that is linked to interleukin-2 deficiency in both locations and (2) persistence of comparatively large numbers of donor-derived leukocytes. These tolerogenic mechanisms are thought to be generic, explaining the tolerance induced by allografts spontaneously, or with the aid of various kinds of immunosuppression

    Idd Loci Synergize to Prolong Islet Allograft Survival Induced by Costimulation Blockade in NOD Mice

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    OBJECTIVE—NOD mice model human type 1 diabetes and are used to investigate tolerance induction protocols for islet transplantation in a setting of autoimmunity. However, costimulation blockade–based tolerance protocols have failed in prolonging islet allograft survival in NOD mice
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