1,038 research outputs found

    Supply-Chain Synchronization: Lessons from Hyundai Motor Company

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    One of the challenges of supply-chain management is developing ways to effectively integrate activities across organizations on the supply chain. Hyundai Motor Company developed mechanisms to coordinate production planning and scheduling activities among supply-chain members. Hyundai Motor\u27s production-and-sales-control (P/SC) department uses regularly scheduled cross-functional meetings and scheduling policies to coordinate supply-chain activities. When implementing this process, the P/SC department overcame structural, environ mental, and behavioral problems. Although Hyundai manage ment concedes that the process is not perfect, communication among supply-chain members has improved, and the P/SC group has successfully promoted mutual understanding and respect among functional areas. The primary benefit, ultimately, is improved customer satisfaction through better integration of functional activities

    Golgins: coiled-coil-rich proteins associated with the Golgi Complex

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    Autoantibodies directed against self-antigens are characteristic features of a number of human diseases. In systemic rheumatic diseases, these include antibodies that react with extracellular molecules; the cell membrane; nuclear and cytoplasmic components. Our laboratories have been interested in understanding autoimmune responses in systemic lupus erythematosus and related disease states and using human autoantibody as molecular probes in studying the cell biology of target antigens. This review summarizes our research efforts in dissecting the autoimmune response to the Golgi complex via expression cloning using human autoantibodies. We have cloned 4 of 5 known Golgi autoantigens that are referred to as golgin-95/GM130, golgin-97, golgin-160/GCP170, and golgin-245, respectively based on their molecular weights. The fifth is giantin, also known as macrogolgin or GCP372. Interestingly, the amino acid sequences deduced for all Golgi autoantigens indicate that they are proteins with predominantly coiled-coil domains and non-alpha helical domains at the N- and C-termini. The current postulate is that these coiled-coil rich proteins like golgin-95/GM130 form intermolecular complexes with a docking protein p115 that has been shown to be important for Golgi vesicular traffic. An alternative nonexclusive hypothesis is that these coiled-coil rich proteins are the components of the "strings" that are important in linking and guiding vesicles in intercisternae traffic. How this family of coiled-coil proteins and their complexes become autoimmune targets remains to be determined

    Microinjection of specific anti-IMPDH2 antibodies induces disassembly of cytoplasmic rods/rings that are primarily stationary and stable structures

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    Background: Our laboratory previously reported interesting rods 3-10 mu m long and rings 2-5 mu m diameter (RR) in the cytoplasm of mammalian cells. Experimental evidence show that both inosine-5'-monophosphate dehydrogenase 2 (IMPDH2) and cytidine triphosphate synthetase (CTPS) are components of RR structures. Several cell types, including mouse embryonic stem cells, and cell lines, such as mouse 3 T3 and rat NRK, naturally present RR structures, while other cells can present RR when treated with compounds interfering with GTP/CTP biosynthetic pathways. in this study, we aimed to investigate the dynamic behavior of these RR in live cells.Results: RR were detected in > 90% of COS-7 and HeLa cells treated with 1 mM ribavirin or 6-Diazo-5-oxo-L-norleucine (DON) for 24 h, and in 75% of COS-7 cells treated with 1 mM mycophenolic acid (MPA) for the same period of time. Microinjection of affinity-purified anti-IMPDH2 antibodies in live COS-7 cells treated with ribavirin, DON, or MPA showed mature forms of RR presented as stable and stationary structures in 71% of cells. in the remaining 29% of cells, RR acquired erratic movement and progressively disassembled into fragments and disappeared within 10 min. the specific stationary state and antibody-dependent disassembling of RR structures was independently confirmed in COS-7 and HeLa cells transfected with GFP-tagged IMPDH2.Conclusions: This is the first demonstration of disassembly of RR structures upon microinjection of anti-IMPDH2 antibodies that led to the disappearance of the molecular aggregates. the disassembly of RR after microinjection of anti-IMPDH2 antibody further strengthens the notion that IMPDH2 are major building blocks of RR. Using two independent methods, this study demonstrated that the induced RR are primarily stationary structures in live cells and that IMPDH2 is a key component of RR.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ Florida, Dept Oral Biol, Gainesville, FL 32610 USAUniversidade Federal de São Paulo, Div Rheumatol, BR-04023062 São Paulo, BrazilFleury Med & Hlth Labs, Div Immunol, BR-04102050 São Paulo, BrazilUniv Idaho, Dept Biol Sci, Moscow, ID 83844 USAUniversidade Federal de São Paulo, Div Rheumatol, BR-04023062 São Paulo, BrazilCAPES: 9028-11-0FAPESP: 2011/12448-0Web of Scienc

    Anti-Rods/Rings: A Human Model of Drug-Induced Autoantibody Generation

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    In recent years, autoantibodies targeting subcellular structures described as the rods and rings pattern in HEp-2 ANA have been presented as a unique case of autoantibody generation. These rod and ring structures (RR) are at least partially composed of inosine monophosphate dehydrogenase type 2 (IMPDH2), and their formation can be induced in vitro by several small-molecule inhibitors, including some IMPDH2 inhibitors. Autoantibodies targeting these relatively unknown structures have been almost exclusively observed in hepatitis C virus (HCV) patients who have undergone treatment with pegylated interferon-alpha/ribavirin (IFN/RBV) combination therapy. To date, anti-RR antibodies have not been found in treatment-naive HCV patients or in patients from any other disease groups, with few reported exceptions. Here, we describe recent advances in characterizing the RR structure and the strong association between anti-RR antibody response and HCV patients treated with IFN/RBV, detailing why anti-RR can be considered a human model of drug-induced autoantibody generation

    Means and method of detection in chemical separation procedures

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    A means and method for indirect detection of constituent components of a mixture separated in a chemical separation process. Fluorescing ions are distributed across the area in which separation of the mixture will occur to provide a generally uniform background fluorescence intensity. For example, the mixture is comprised of one or more charged analytes which displace fluorescing ions where its constituent components separate to. Fluorescing ions of the same charge as the charged analyte components cause a displacement. The displacement results in the location of the separated components having a reduced fluorescence intensity to the remainder of the background. Detection of the lower fluorescence intensity areas can be visually, by photographic means and methods, or by automated laser scanning

    Immune Response-Dependent Assembly of IMP Dehydrogenase Filaments

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    Inosine monophosphate dehydrogenase (IMPDH) catalyzes the conversion of IMP to xanthosine monophosphate, the rate-limiting step in de novo guanosine monophosphate (GMP) synthesis. In cultured cells, IMPDH polymerizes into micron-scale filamentous structures when GMP synthesis is inhibited by depletion of purine precursors or by various drugs, including mycophenolic acid, ribavirin, and methotrexate. IMPDH filaments also spontaneously form in undifferentiated mouse embryonic stem cells and induced pluripotent stem cells, hinting they might function in various highly proliferative cell types. Therefore, we investigated IMPDH filament formation in human and murine T cells, which rely heavily on de novo guanine nucleotide synthesis to rapidly proliferate in response to antigenic challenge. We discovered extensive in vivo IMPDH filament formation in mature T cells, B cells, and other proliferating splenocytes of normal, adult B6 mice. Both cortical and medullary thymocytes in young and old mice also showed considerable assembly of IMPDH filaments. We then stimulated primary human peripheral blood mononuclear cells ex vivo with T cell mitogens phytohemagglutinin (PHA), concanavalin A (ConA), or antibodies to CD3 and CD28 for 72 h. We detected IMPDH filaments in 40–60% of T cells after activation compared to 0–10% of unstimulated T cells. Staining of activated T cells for the proliferation marker Ki-67 also showed an association between IMPDH filament formation and proliferation. Additionally, we transferred ovalbumin-specific CD4+ T cells from B6.OT-II mice into B6.Ly5a recipient mice, challenged these mice with ovalbumin, and harvested spleens 6 days later. In these spleens, we identified abundant IMPDH filaments in transferred T cells by immunofluorescence, indicating that IMPDH also polymerizes during in vivo antigen-specific T cell activation. Overall, our data indicate that IMPDH filament formation is a novel aspect of T cell activation and proliferation, and that filaments might be useful morphological markers for T cell activation. The data also suggest that in vivo IMPDH filament formation could be occurring in a variety of proliferating cell types throughout the body. We propose that T cell activation will be a valuable model for future experiments probing the molecular mechanisms that drive IMPDH polymerization, as well as how IMPDH filament formation affects cell function

    Longitudinal Study of a Human Drug-Induced Model of Autoantibody to Cytoplasmic Rods/Rings following HCV Therapy with Ribavirin and Interferon-alpha

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    Background: A novel pattern in the indirect immunofluorescence antinuclear antibody assay on HEp-2 cells (IIF-HEp-2) characterized by cytoplasmic rods and rings (RR) was reported in HCV patients, but stringent disease specificity studies and longitudinal analysis are lacking. We investigated the clinical significance of anti-RR in an HCV cohort with up to a 12-month treatment follow up.Methodology/Results: 597 patients (342 HCV, 55 HCV/HIV, 200 non-HCV) were screened and titered for anti-RR. Serial samples were available from 78 of 176 treated and 27 of 166 untreated patients. Anti-RR was detected in 14.1% of 342 HCV patients, 9.1% of 55 HCV/HIV, 3.4% of 29 Hepatitis B, and none of 171 non-HCV (p47% tested positive for anti-RR. the anti-RR titer generally increased with sustained treatment and remained high in 53% of patients. After treatment, anti-RR titer was negative in 41%. Non-responders to HCV therapy were 77% in anti-RR-positive versus 64% in anti-RR-negative patients. Response to treatment was not associated with anti-RR titer or the dynamics of anti-RR reactivity during and after treatment.Conclusions: the exquisite association of anti-RR reactivity with combined interferon-a/ribavirin therapy in HCV patients represents a unique model for drug-induced autoantibody generation in humans as demonstrated by the fact that a significant fraction of patients who have anti-RR during therapy becomes anti-RR-negative after completion of therapy.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Brazilian National Council for Research and Technological DevelopmentUniversidade Federal de São Paulo, Div Rheumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Gastroenterol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilFleury Med & Hlth Labs, Div Immunol, São Paulo, BrazilUniv Florida, Dept Oral Biol, Gainesville, FL 32610 USAUniversidade Federal de São Paulo, Div Rheumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Gastroenterol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilFAPESP: 2010/50710-6Brazilian National Council for Research and Technological Development: 305064/2011-8Web of Scienc

    Effect of dephasing on mesoscopic conductance fluctuations in quantum dots with single channel leads

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    We consider the distribution of conductance fluctuations in disordered quantum dots with single channel leads. Using a perturbative diagrammatic approach, valid for continuous level spectra, we describe dephasing due to processes within the dot by considering two different contributions to the level broadening, thus satisfying particle number conservation. Instead of a completely non-Gaussian distribution, which occurs for zero dephasing, we find for strong dephasing that the distribution is mainly Gaussian with non-universal variance and non-Gaussian tails.Comment: 11 pages in REVTeX two-column format; 6 eps figures included; submitted to Phys. Rev.
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