bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cellular growth and rearrangement during the development of the mammalian organ of Corti
Authors: McKenzie Erynn , Krupin Alison , Kelley Matthew W. 
Published: March 2004

AbstractThe sensory epithelium of the mammalian cochlea, the organ of Corti, is comprised of ordered rows of cells, including inner and outer hair cells. Recent results suggest that physical changes in the overall size and shape of the cochlear duct, including possible convergence and extension, could play a role in the development of this pattern. To examine this hypothesis, changes in cell size and distribution were determined for different regions of the cochlea duct during embryonic development. In addition, changes in the spatial distribution of sensory precursor cells were determined at different developmental time points based on expression of p27kip1. Unique changes in luminal surface area, cell density, and number of cell contacts were observed for each region of the duct. Moreover, the spatial distribution of p27kip1‐positive cells changed from short and broad early in development, to long and narrow. These results are consistent with the hypothesis that convergence and extension plays a role in cellular patterning within the organ of Corti. Developmental Dynamics 229:802–812, 2004. Published 2004 Wiley‐Liss, Inc.
Intestinal intraepithelial lymphocytes prevent pathogen‐driven inflammation and regulate the Smad/T‐bet pathway of lamina propria CD4+ T cells
Authors: Mennechet Franck J. D. , Kasper Lloyd H. , Rachinel Nicolas , Minns Laurie A. , Luangsay Souphalone , Vandewalle Alain , Buzoni‐Gatel Dominique 
Published: March 2004

AbstractIntraepithelial lymphocytes (IEL) play a key role in gut homeostasis and are critical effector cells preventing the inflammatory intestinal lesions induced in mice following oral infection with Toxoplasma gondii. In this intestinal inflammatory model, CD4+ T lymphocytes from the lamina propria (LP) synergize with the infected enterocytes to secrete pro‐inflammatory chemokines and cytokines. In this study, we assessed the mechanisms accounting for the ability of IEL to modulate the inflammatory activity of these cells. Adoptive transfer of IEL purified from wild‐type mice, or CD154‐,CD95L‐ or IL‐10‐deficient mice infected with T. gondii completely impairs the development of the lethal ileitis in recipient mice orally infected with T. gondii.Compared with unprimed IEL isolated from naive mice, the CD8α β TCRα β subset of primed IEL, isolated from T. gondii‐infected mice, secretes increased amount of TGF‐β. IEL interact with the LP CD4+ T lymphocytes, down‐regulate their production of inflammatory cytokines such as IFN‐γ and reduce their proliferative activity. These effects are linked to the secretion of TGF‐β and are correlated with a shift in the balance between Smad7/T‐bet down‐regulation and Smad2/Smad3 up‐regulation in LP CD4+ T lymphocytes.
Mechanisms of tolerance induced by TGFβ‐treated APC: CD4 regulatory T cells prevent the induction of the immune response possibly through a mechanism involving TGFβ
Authors: Alard Pascale , Clark Sherry L. , Kosiewicz Michele M. 
Published: March 2004

AbstractTransforming growth factor β (TGFβ)‐treated antigen‐presenting cells (APC) pulsed with antigen induce tolerance in mice, i.e. inhibition of IFN‐γ production and delayed type hypersensitivity response. Although evidence suggests that regulatory T cells are involved, their mechanism of action is currently unknown and is the subject of the present study. Both CD4 and CD8 splenic T cells from mice injected i.v. with adherent thioglycolate‐elicited peritoneal exudate cells cultured with TGFβ2 and antigen (TGFβ‐treated APC) transferred tolerance to naive recipients. Interestingly, TGFβ‐treated APC from class II knockout mice were unable to induce tolerance in wild‐type mice, whereas wild‐type TGFβ‐treated APC could induce tolerance in CD8 knockout mice. TGFβ was detected in cultures of lymphoid cells from mice injected with TGFβ‐treated APC, and treatment with anti‐TGFβ antibody in vivo impaired tolerance induction. TGFβ appeared to be involved in both the development of CD4 regulatory T cells and the effector function of the CD4 regulatory T cells. In summary, the important findings in this study are that CD4, and not CD8, regulatory T cells are required for tolerance induced by TGFβ‐treated APC in naive mice, and tolerance appears to be mediated by a mechanism involving TGFβ.
Anti‐Gal IgG potentiates natural killer cell migration across porcine endothelium via endothelial cell activation and increased natural killer cell motility triggered by CD16 cross‐linking
Authors: Hauzenberger Elenor , Klominek Julius , Holgersson Jan 
Published: March 2004

AbstractXenoreactive antibodies (Ab) are important for the development of acute vascular rejection (AVR) of xenografts characterized by monocytes, natural killer (NK) cells and neutrophils infiltrating the graft. The mechanisms by which anti‐galactoseα1,3galactose (α‐Gal) IgG influence NK cell migration across porcine aortic endothelium (PAEC) were investigated. NK cell migration across PAEC increased in the presence of anti‐α‐Gal IgG. Anti‐α‐Gal IgG exposure activated PAEC as shown by an increased expression of CD62E and CD106. NK cells adhered, spread and showed motile forms on plastic surfaces coated with human IgG, IgG Fc and on mAb against CD16, but not on mouse IgG or BSA, suggesting that CD16 cross‐linking can mediate increased adhesiveness. Increased NK cell motility was observed on Boyden filters coated with human IgG, IgG Fc, and mAb against CD16 and the α4, α5, αL, β1 and β2 integrin chains. No motile response was seen on mouse IgGor CD7, CD56 and α6 integrin mAb. NK cell migration on human IgG and anti‐CD16 Ab was blocked by anti‐CD16 or anti‐β2, but not anti‐β1 Ab, implying that the motile response triggered by CD16 cross‐linking is mediated via β2 integrins. Preformed or induced anti‐α‐Gal IgG may therefore contribute to AVR by stimulating innate immune cell infiltration of the graft.
Toll‐like receptor stimulation induces airway hyper‐responsiveness to bradykinin, an effect mediated by JNK and NF‐κB signaling pathways
Authors: Bachar Ofir , Adner Mikael , Uddman Rolf , Cardell Lars‐Olaf 
Published: March 2004

AbstractAirway infections induce hyper‐responsiveness in asthmatic patients. Toll‐like receptors (TLR) mediate inflammatory responses to microbes. Occurrence and effects of TLR2, TLR3 and TLR4 were examined in a mouse organ culture model of asthma focusing on the smooth muscle responses to bradykinin. TLR2, TLR3 and TLR4 mRNA, and TLR2 and TLR4 immunoreactivity were detected in the tracheal muscle layer. Tracheal organ culture for 1 or 4 days with lipopolysaccharide (LPS; TLR2/4 agonist) or polyinosinic polycytidylic acid (poly‐I‐C; TLR3 agonist) enhanced bradykinin‐ and [des‐Arg9]‐bradykinin‐induced contractions. Simultaneous LPS and poly‐I‐C treatment resulted in synergistic enhancement of bradykinin‐induced contraction. In carbachol‐pre‐contracted segments TLR stimulationinduced less potent relaxations to bradykinin and [des‐Arg9]‐bradykinin. The LPS and poly‐I‐C enhancement of bradykinin‐induced contraction was inhibited by the transcriptional inhibitor actinomycin‐D, dexamethasone, the proteasome inhibitor MG‐132 and the c‐Jun N‐terminal kinase (JNK) inhibitor SP600125. LPS and poly‐I‐C induced translocation of NF‐κB p65 to the nucleus and up‐regulation of kinin B1 and B2 receptor mRNA. In summary, TLR2, TLR3 and TLR4 are expressed in the mouse tracheal smooth muscle. Costimulation of these receptors results in NF‐κB‐ and JNK‐mediated transcription of B1 and B2 receptor, inducing hyper‐responsiveness to bradykinin.
Aberrant expression of α‐Gal on primary human endothelium does not confer susceptibility to NK cell cytotoxicity or increased NK cell adhesion
Authors: He Zhong , Ehrnfelt Cecilia , Kumagai‐Braesch Makiko , Islam Khalid B. , Holgersson Jan 
Published: March 2004

AbstractThe contribution of Galα1,3Gal (α‐Gal) to cell‐mediated organ xenograft rejection is controversial. We have used recombinant lentiviruses encoding a porcine α1,3 galactosyltransferase (α1,3GalT) to obtain α‐Gal‐expressing primary human aortic endothelial cells (HAEC) at a frequency of 70–90%. These cells were compared to non‐transduced and mock‐transduced HAEC with regard to their susceptibility to human NK cell‐mediated lysis, ability to stimulate IFN‐γ production by NK cells, and support of NK cell adhesion under static and dynamic conditions. Using green fluorescent protein (GFP) as a reporter gene, it was shown that the frequency of green fluorescent HAEC increased until day 5 post‐transduction, and at a multiplicity of infection of 2.5, it reached98%. Lentiviral transduction did not result in activation of HAEC, and transduced HAEC responded as expected to TNF‐α and IFN‐γ stimulation. No differences were detected between non‐α‐Gal‐ and α‐Gal‐expressing HAEC in terms of their susceptibility to NK cell‐mediated lysis, ability to stimulate IFN‐γ production by NK cells, or ability to support NK cell adhesion under static and dynamic conditions. In conclusion, these data argue against an important role for the α‐Gal epitope in the direct interaction between endothelium and NK cells and prove that recombinant lentiviruses are efficient gene carriers for primary human endothelial cells.
NF‐κB synergizes with NF‐AT and NF‐IL6 in activation of the IL‐4 gene in T cells
Authors: Li‐Weber Min , Giaisi Marco , Baumann Sven , Pálfi Katalin , Krammer Peter H. 
Published: March 2004

AbstractIL‐4 plays a pivotal role in the development of the Th2 cell mediated humoral immune response and causes IgE‐dependent allergic inflammatory diseases. Expression of IL‐4 in differentiated Th2 cells is regulated by transcription factors such as NF‐AT, AP‐1 and NF‐IL6. Recently, increasing evidence indicates that the pro‐inflammatory transcription factor NF‐κB may also participate inIL‐4 expression. In this study, we show that the IL‐4 promoter is synergistically activated by NF‐κB, NF‐AT and NF‐IL6 at the NF‐κB/NF‐AT/NF‐IL6 composite sites. In addition, we performed the chromatin immunoprecipitation technique to determine the functional relevance of NF‐κB in the activation of the IL‐4 gene in vivo. We demonstrate that NF‐κB binds to the IL‐4 promoter in vivo upon T cell activation. Inhibition of NF‐κB nuclear translocation in living cells blocked binding of NF‐κB to the IL‐4 promoter. The data provide first evidence that NF‐κB is directly involved in IL‐4 transcription.
Identification of naturally processed CD8 T cell epitopes from prostein, a prostate tissue‐specific vaccine candidate
Authors: Friedman Rachel S. , Spies A. Gregory , Kalos Michael 
Published: March 2004

AbstractProstein is a prostate tissue‐specific protein that is uniquely and abundantly expressed in normal and cancerous prostate tissues. Due to this expression profile, we examined the immunogenicity of prostein as a potential vaccine candidate for prostate cancer. To determine the presence of CD8 T cells specific for naturally processed prostein‐derived epitopes in healthy individuals, we developed and applied an in vitro stimulation protocol. Using this protocol, we identified CD8 T cells specific for prostein in the peripheral blood of a male and a female donor. Prostein‐specific CD8 T cell clones specifically recognized prostein‐expressing targets, including prostate tumor cell lines expressing the relevant HLA alleles. CD8 T cell clones isolated from the male donor were significantly less effective in recognizing target cells compared to cells isolated from the female donor and appeared to recognize subdominant epitopes. The identification of a prostein‐specificCD8 T cell repertoire supports the development of prostein in vaccination strategies against prostate cancer. Furthermore, the naturally processed peptide epitopes identified provide tools for the development of peptide‐based vaccination strategies against prostate cancer and for monitoring of prostein‐specific responses in vaccinated patients.
Role of TCR‐restricting MHC density and thymic environment on selection and survival of cells expressing low‐affinity T cell receptors
Authors: Martinic Marianne M. , Rocha Benedita , McCoy Kathy D. , Hengartner Hans , Zinkernagel Rolf M. 
Published: March 2004

AbstractH‐Y‐specific T cell receptor (TCR) transgenic mice express an MHC class I H‐2Db‐restricted TCR specific for a male antigen‐derived peptide (H‐Y). Selection and survival of cells expressing this low‐affinity TCR were analyzed under optimal and sub‐optimal conditions. Optimal conditions were provided by a thymic environment with high H‐2Db density. Sub‐optimal conditions were provided by a thymic environment with decreased H‐2Db density or by an athymic environment with either high or low H‐2Db density. Whereas negative selection was still guaranteed under sub‐optimal conditions, selection and survival efficiency of cells expressing the transgenic TCR were strongly dependent on optimal conditions. These results indicated that both a thymic microenvironment and a high density of TCR‐restricting MHC molecules were needed to ensure selection and maintenance of cells expressing TCR with low affinity and hence a more diverse T cell repertoire.
Mini‐review: Presentation of pathogen‐derived antigens in vivo
Authors: Lauvau Grégoire , Glaichenhaus Nicolas 
Published: March 2004

AbstractMost intracellular pathogens induce robust T cell responses upon infection of mammalian hosts. In most cases, these T cell responses are protective and result in pathogen clearance. It is therefore important to determine how T cells are primed and how they differentiate into cytokine‐secreting and/or cytotoxic effector cells. In contrast to B cells, which recognize soluble Ag, CD8+ and CD4+ T cells react to Ag‐derived peptides bound to MHC I or MHC II molecules, respectively. Therefore, elucidating the mechanisms by which pathogen‐derived Ag become available for presentation is necessary to understand how pathogens trigger T cell responses in vivo. Although many excellent reviews have focused on the mechanisms involved in Ag processing, very few have pointed to the specificity of host–pathogen interactions. In this respect, it should be noticed that these interactions are very different from one pathogen to another, and may result in the involvement of different cells and molecules. Because of space limitations, we have decided to focus this review on two intracellular pathogens — vaccinia virus and Listeria monocytogenes. We have chosen these two pathogens because they both induce a strong CD8+ T cell response and because they have been extensively studied by both microbiologists and immunologists.
Synthesis, Structural and Spectroscopic Characterization of Four [(η6‐PAH)Cr(CO)3] Complexes (PAH = Pyrene, Perylene, Chrysene, 1,2‐Benzanthracene)
Authors: Arrais Aldo , Diana Eliano , Gervasio Giuliana , Gobetto Roberto , Marabello Domenica , Stanghellini Pier Luigi 
Published: March 2004

AbstractThe thermal reaction of hexacarbonylchromium with the polycyclic aromatic hydrocarbons (PAHs) pyrene, perylene, chrysene and 1,2‐benzanthracene has afforded four organometallic complexes of the type [(η6‐PAH)Cr(CO)3], whose unprecedented structures were obtained by single‐crystal X‐ray analysis. The topology of the coordination of the Cr(CO)3 fragment and its asymmetry with respect to the coordinating ring may depend on the opportunity to maintain the maximum aromaticity of the complexed ligand. DFT calculations, 1H NMR, FT‐IR and Raman spectroscopy have been used to elucidate the type of interaction between the PAH ligand and the carbonylmetal moiety, giving insight into the ligand‐to‐metal donor capacity and the intra‐ and intermolecular interactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis and Structure of an Unprecedented Layered Vanadate Complex Containing Double‐Helical Chains: [{CoIII(phen)2}2V8O23]
Authors: Xiao Dongrong , Xu Yan , Hou Yu , Wang Enbo , Wang Shutao , Li Yangguang , Xu Lin , Hu Changwen 
Published: March 2004

AbstractA novel two‐dimensional organic−inorganic hybrid vanadate complex [{CoIII(phen)2}2V8O23] has been hydrothermally synthesized and characterized by elemental analyses, IR spectroscopy, XPS spectroscopy, TG analysis and single‐crystal X‐ray diffraction. The single‐crystal X‐ray diffraction analysis reveals that compound 1 contains an unprecedented neutral 2D framework constructed of 4,10,12‐net sheets. To the best of our knowledge, compound 1 represents the first example of 2D layered vanadium oxide complex constructed of 4,10,12‐net sheets. Furthermore, the title compound consists of left‐handed and right‐handed helical chains, which are further interconnected to form the double‐helical chains. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Structural Characterizations and Magnetic Properties of a Series of Mono‐, Di‐ and Polynuclear Manganese Pyridinecarboxylate Compounds
Authors: Huang Deguang , Wang Wenguo , Zhang Xiaofeng , Chen Changneng , Chen Feng , Liu Qiutian , Liao Daizheng , Li Licun , Sun Licheng 
Published: March 2004

AbstractSeven new manganese(II, III, IV) pyridinecarboxylate compounds (Et4N)[MnCl2(pic)2] (1, Hpic = picolinic acid) [MnCl(pic)2(H2O)]·H2O (2), [MnCl(pic)(H2O)2]n (3), [Mn(pic)2]n (4), [MnCl(pic)]n (5), [MnCl2(4‐C5H4NHCOO)]n (6) and [Mn2O2(pic)4] (7) were synthesized and structurally characterized. The picolinate ligand coordinates to the Mn ion forming a chelating five‐membered ring which constructs diverse architectures by various bridging modes, such as μ‐Cl, μ1,1‐ and μ1,3‐carboxylate bridges (syn‐syn and syn‐anti modes). The interaction between the pyridyl rings is discussed, displaying a face‐to‐face π‐π stacking for complex 6 and a T‐shaped C−H···π attraction for complex 4. Complex 3 has an infinite zigzag chain structure in which two neighboring Mn ions are linked by a carboxylate bridge in a syn‐anti mode. In complex 4, the Mn(pic)2 fragments are joined to each other by double μ1,1‐carboxylate bridges, forming a 2D layer structure. Complex 5 contains Mn4O4 square subunits which are connected by double μ‐Cl bridges to form a grid‐like 2D structure. The isonicotinate complex 6 has a zigzag chain structure containing mixed double μ‐Cl and μ1,3‐carboxylate bridges in a syn‐syn mode. Protonation at the pyridyl‐N position was found and identified by the IR and magnetic properties of 6. The participation of an oxidizing agent like MnO4− leads to complexes containing higher valent manganese (1, 2 and 7). The IR spectra of these complexes are discussed and found to be consistent with the structural features. The magnetic properties of complexes 4, 5 and 6 have been investigated. Antiferromagnetic coupling interactions were observed and satisfactory fitting results were obtained with J values ranging from −0.63 cm−1 to −2.35 cm−1. The magnetic parameters of these complexes, together with the parameters of other Mn complexes with comparable structures, are compared and discussed based on the bridging modes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Syntheses, Crystal Structures and Electrospray Mass Spectra of Coordination Polymers of an N,N′‐Bis(3‐pyridylmethyl)‐1,4‐benzenebis(methylamine) Ligand and Silver(I) Salts
Authors: Zhu Hui‐Fang , Kong Ling‐Yan , Okamura Taka‐aki , Fan Jian , Sun Wei‐Yin , Ueyama Norikazu 
Published: March 2004

AbstractFour new coordination frameworks {[Ag2(L1)](NO3)2·2H2O}n (1), {[Ag(L1)](CF3COO)·2.5H2O}n (2), {[Ag2(L1)2][1,4‐C6H4(COO)2]·7H2O}n (3) and {[Ag(L1)]ClO4}n (4) were obtained by the reaction of N,N′‐bis(3‐pyridylmethyl)‐1,4‐benzenebis(methylamine) (L1) with the corresponding silver(I) salts. X‐ray diffraction analyses reveal that complex 1 has an infinite 1D chain structure, in which L1 acts as a tetradentate ligand. Complexes 2, 3 and 4 have 2D network structures, and the L1 ligands in these complexes adopt two different coordination modes: one kind of ligand coordinates four silver(I) atoms using its four N atoms, and the other kind of ligand connects only two silver(I) atoms with the two N atoms of the benzenebis(methylamine) unit, while the pyridine units remain free of coordination. Complex {[Ag(L2)]ClO4}n (5) was synthesized by reaction of N,N′‐bis(3‐pyridylmethyl)‐1,4‐benzenebis(methyleneamine) (L2) with silver(I) perchlorate. It has a novel 1D chain structure, which is different from that of 4 due to the different flexibility of the ligands L1 and L2. All of these complexes form 2D or 3D structures stabilized by hydrogen bonding, C−H···π and π‐π interactions. The results revealed that the nature of the counteranions and the flexibility of the ligand have an impact on the structure of the supramolecular architectures. The complexes were also characterized by electrospray mass spectrometry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Self‐Assembly of Bis(pyrrol‐2‐ylmethyleneamine) Ligands with CuII Controlled by Bridging [−(CH2)n−] Spacers and Weak Intermolecular C−H···Cu Hydrogen Bonding
Authors: Yang Lanying , Chen Qingqi , Li Yan , Xiong Shaoxiang , Li Genpei , Ma Jin Shi 
Published: March 2004

AbstractBis(pyrrol‐2‐ylmetyhleneamine) ligands linked by alkyl spacers between the imine nitrogens are shown to give dinuclear dimers or mononuclear monomers, depending on the length of the alkyl linker, upon coordination with CuII. Ligands containing ethylene or hexylene linkers −(CH2)n− (n = 2, 6) give dinuclear dimers 5 and 8, while propylene and butylene chains (n = 3, 4) give mononuclear monomers 6 and 7. X‐ray crystal structural analysis reveals that 5 exists as two very similar isomers 5a and 5b, in which the two ligands are bound to two CuII centers to form a distorted helical conformation. In the unit cells of 8, two entirely different isomers 8a and 8b are found. In 8a two ligands are side‐by‐side bound to two CuII centers to form a rectangular macrocycle, while in 8b they are bonded to two CuII centers to form a distorted double‐stranded helix. Moreover, X‐ray structural analysis reveals that complexes 5−8 are further assembled into one‐dimensional polymers through weak, intermolecular C−H···Cu hydrogen bonding, which plays a crucial role in stabilizing the crystal lattice. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Syntheses and Structural Characterization of AgI Complexes with the N,N′‐Di(2‐pyridyl)oxamide Ligand
Authors: Hsu Yi‐Fen , Chen Jhy‐Der 
Published: March 2004

AbstractA series of the silver(I) complexes {[Ag(L)][NO3]}∞ (1), {[Ag(L)(CH3CN)][ClO4]}∞ (2), {[Ag2(L)3(CH3CN)2][PF6]2}∞ (3), and [Ag3(L)4(CH3CN)4][BF4]3 (4) [where L = N,N′‐di(2‐pyridyl)oxamide] have been prepared by the reactions of AgX (X = NO3−, ClO4−, PF6− and BF4−) with L. All the complexes have been structurally characterized by X‐ray crystallography, confirming that 1−3 are coordination polymers whereas 4 is a trinuclear complex. Complex 1 forms helical chains which are interlinked through a series of Ag···O interactions and C−H···O hydrogen bonds. In complexes 2 and 3, a new set of interactions involving two Ag···O interactions and self‐complementary double N−H···O hydrogen bonds were found to link the linear chains and ladder structures into polymer pairs (for 2) and molecular sheets (for 3). In complex 4, the molecules are interlinked by extensive Ag···N interactions and π−π stacking interactions to form molecular bands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)