47 research outputs found

    Detection of immune-complex-dissociated nonstructural-1 antigen in patients with acute dengue virus infections

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    Accurate and timely diagnosis of dengue virus (DEN) infections is essential for the differential diagnosis of patients with febrile illness and hemorrhagic fever. In the present study, the diagnostic value of a newly developed immune-complex dissociated nonstructural-1 (NS-1) antigen dot blot immunoassay (DBI) was compared to a commercially available DEN antigen detection kit (denKEY Blue kit; Globio Co., Beverly, Mass.) and a reverse transcription-PCR (RT-PCR) kit. Serial serum or plasma samples (n = 181) obtained from 55 acute DEN-infected patients were used. In samples obtained from 32 of these 55 DEN-infected patients, viral RNA could be detected by RT-PCR. DEN antigen was detected in only 10 of these 55 patient samples by using the denKEY kit. When these samples were treated with acid to release the immune-complex-associated NS-1 antigen for detection by DBI, 43 of these 55 patients were found to be positive for DEN NS-1 antigen. In nondiss

    Optical creation of vibrational intrinsic localized modes in anharmonic lattices with realistic interatomic potentials

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    Using an efficient optimal control scheme to determine the exciting fields, we theoretically demonstrate the optical creation of vibrational intrinsic localized modes (ILMs) in anharmonic perfect lattices with realistic interatomic potentials. For systems with finite size, we show that ILMs can be excited directly by applying a sequence of femtosecond visible laser pulses at THz repetition rates. For periodic lattices, ILMs can be created indirectly via decay of an unstable extended lattice mode which is excited optically either by a sequence of pulses as described above or by a single picosecond far-infrared laser pulse with linearly chirped frequency. In light of recent advances in experimental laser pulse shaping capabilities, the approach is experimentally promising.Comment: 20 pages, 7 eps figures. Accepted, Phys. Rev.

    The Sequence of Delta24-RGD and TMZ Administration in Malignant Glioma Affects the Role of CD8+T Cell Anti-tumor Activity

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    The conditionally replicating oncolytic adenovirus Delta24-RGD (Ad) is currently under investigation in clinical trials for glioblastoma, including in combination with temozolomide (TMZ), the standard chemotherapy for this tumor. Previously, we showed that the efficacy of Delta24-RGD in a murine model is primarily dependent on the virus-induced anti-tumor immune response. As observed with most chemotherapies, TMZ has pronounced immune-modulating effects. Here, we studied the combined effects of these treatments in a murine glioma model. In vitro, we observed a synergistic activity between Delta24-RGD and TMZ. In vivo, C57BL/6 mice bearing intracranial GL261 tumors were treated with TMZ for 5 days either prior to intratumoral Delta24-RGD injection (TMZ/Ad) or post virus injection (Ad/TMZ). Notably, the Ad/TMZ regimen led to similar tumoral CD8+ T cell influx as the virus-only treatment, but increased the ability of CD8+ T cells to specifically recognize the tumor cells. This was accompanied by improved survival. The TMZ/Ad regimen also improved survival significantly compared to controls, but not compared to virus alone. In this group, the influx of dendritic cells is impaired, followed by a significantly lower number of tumor-infiltrating CD8+ T cells and no recognition of tumor cells. Depletion of either CD4+ T cells or CD8+ T cells impaired the efficacy of Delta24-RGD, underscoring the role of these cells in therapeutic activity of the virus. Overall, we show that the addition of TMZ to Delta24-RGD treatment leads to a significant increase in survival and that the order of sequence of these treatments affects the CD8+T cell anti-tumor activity

    An Essential Role for DYF-11/MIP-T3 in Assembling Functional Intraflagellar Transport Complexes

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    MIP-T3 is a human protein found previously to associate with microtubules and the kinesin-interacting neuronal protein DISC1 (Disrupted-in-Schizophrenia 1), but whose cellular function(s) remains unknown. Here we demonstrate that the C. elegans MIP-T3 ortholog DYF-11 is an intraflagellar transport (IFT) protein that plays a critical role in assembling functional kinesin motor-IFT particle complexes. We have cloned a loss of function dyf-11 mutant in which several key components of the IFT machinery, including Kinesin-II, as well as IFT subcomplex A and B proteins, fail to enter ciliary axonemes and/or mislocalize, resulting in compromised ciliary structures and sensory functions, and abnormal lipid accumulation. Analyses in different mutant backgrounds further suggest that DYF-11 functions as a novel component of IFT subcomplex B. Consistent with an evolutionarily conserved cilia-associated role, mammalian MIP-T3 localizes to basal bodies and cilia, and zebrafish mipt3 functions synergistically with the Bardet-Biedl syndrome protein Bbs4 to ensure proper gastrulation, a key cilium- and basal body-dependent developmental process. Our findings therefore implicate MIP-T3 in a previously unknown but critical role in cilium biogenesis and further highlight the emerging role of this organelle in vertebrate development

    Competence in Bacillus subtilis is controlled by regulated proteolysis of a transcription factor.

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    Competence is a physiological state, distinct from sporulation and vegetative growth, that enables cells to bind and internalize transforming DNA. The transcriptional regulator ComK drives the development of competence in Bacillus subtilis. ComK is directly required for its own transcription as well as for the transcription of the genes that encode DNA transport proteins. When ComK is sequestered by binding to a complex of the proteins MecA and ClpC, the positive feedback loop leading to ComK synthesis is interrupted. The small protein ComS, produced as a result of signaling by a quorum-sensing two-component regulatory pathway, triggers the release of ComK from the complex, enabling comK transcription to occur. We show here, based on in vivo and in vitro experiments, that ComK accumulation is also regulated by proteolysis and that binding to MecA targets ComK for degradation by the ClpP protease in association with ClpC. The release of ComK from binding by MecA and ClpC, which occurs when ComS is synthesized, protects ComK from proteolysis. Following this release, the rates of MecA and ComS degradation by ClpCP are increased in our in vitro system. In this novel system, MecA serves to recruit ComK to the ClpCP protease and connects ComK degradation to the quorum-sensing signal-transduction pathway, thereby regulating a key developmental process. This is the first regulated degradation system in which a specific targeting molecule serves such a function

    Antagonistic sensory cues generate gustatory plasticity in Caenorhabditis elegans

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    Caenorhabditis elegans shows chemoattraction to 0.1–200 mM NaCl, avoidance of higher NaCl concentrations, and avoidance of otherwise attractive NaCl concentrations after prolonged exposure to NaCl (gustatory plasticity). Previous studies have shown that the ASE and ASH sensory neurons primarily mediate attraction and avoidance of NaCl, respectively. Here we show that balances between at least four sensory cell types, ASE, ASI, ASH, ADF and perhaps ADL, modulate the response to NaCl. Our results suggest that two NaCl-attraction signalling pathways exist, one of which uses Ca(2+)/cGMP signalling. In addition, we provide evidence that attraction to NaCl is antagonised by G-protein signalling in the ASH neurons, which is desensitised by the G-protein-coupled receptor kinase GRK-2. Finally, the response to NaCl is modulated by G-protein signalling in the ASI and ADF neurons, a second G-protein pathway in ASH and cGMP signalling in neurons exposed to the body fluid
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