297 research outputs found

    Development of Atmospheric Monitoring System at Akeno Observatory for the Telescope Array Project

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    We have developed an atmospheric monitoring system for the Telescope Array experiment at Akeno Observatory. It consists of a Nd:YAG laser with an alt-azimuth shooting system and a small light receiver. This system is installed inside an air conditioned weather-proof dome. All parts, including the dome, laser, shooter, receiver, and optical devices are fully controlled by a personal computer utilizing the Linux operating system. It is now operated as a back-scattering LIDAR System. For the Telescope Array experiment, to estimate energy reliably and to obtain the correct shower development profile, the light transmittance in the atmosphere needs to be calibrated with high accuracy. Based on observational results using this monitoring system, we consider this LIDAR to be a very powerful technique for Telescope Array experiments. The details of this system and its atmospheric monitoring technique will be discussed.Comment: 24 pages, 13 figures(plus 3 gif files), Published in NIM-A Vol.488, August 200

    Toll‐like receptor signalling induces the expression of serum amyloid A in epidermal keratinocytes and dermal fibroblasts

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    BACKGROUND: Toll-like receptors (TLRs) play critical roles in innate immune response by sensing pathogen- or damage-associated molecular patterns. Epidermal keratinocytes and dermal fibroblasts also produce proinflammatory cytokines and chemokines under stimulation with TLR ligands. Serum amyloid A (SAA) is an essential factor in the pathogenesis of secondary amyloidosis, and also has immunomodulatory functions. SAA are produced mainly by hepatocytes but also by a variety of cells, including immune cells, endothelial cells, synoviocytes, and epidermal keratinocytes. However, SAA expression in human dermal fibroblasts has not been shown to date. AIM: To investigate the effect of TLR ligands on SAA expression in epidermal keratinocytes and dermal fibroblasts. METHODS: We investigated whether TLR ligands induce the expression of SAA in normal human epidermal keratinocytes (NHEKs) and normal human dermal fibroblasts (NHDFs) by real-time quantitative PCR and ELISA. The effect of SAA on its own expression in NHDFs was also studied. RESULTS: SAA expression was induced via nuclear factor-κB by TLR1/2, 3, 5 and 2/6 ligands in NHEKs. In NHDFs, TLR1/2 and TLR2/6 ligands increased SAA expression. SAA further induced its own expression via TLR1/2 and NF-κB in NHDFs, as previously reported for NHEKs. CONCLUSIONS: Our results provide new evidence that the skin's innate immune response contributes to the production of SAA, which might lead to an increased risk of systemic complications such as secondary amyloidosis of recessive dystrophic epidermolysis bullosa

    Cathelicidin antimicrobial peptide LL-37 augments interferon-beta expression and antiviral activity induced by double-stranded RNA in keratinocytes

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    Background Cathelicidin antimicrobial peptide LL-37 has the capacity to kill a wide range of microbes and to modify host immunity. Recently, our group observed that the activation of keratinocytes by LL-37 and DNA greatly increases interferon (IFN)-beta through Toll-like receptor (TLR) 9. However, the effect of LL-37 on the induction of IFN-beta through TLR3, a sensor of double-stranded (ds) RNA, in keratinocytes is not well known. Objectives To investigate whether LL-37 could affect TLR3 signalling and antiviral activity in normal human epidermal keratinocytes (NHEKs). Methods We investigated the production of IFN-beta in NHEKs stimulated with a TLR3 ligand, poly (I:C), in the presence of LL-37. To examine the effect of LL-37 and poly (I:C) on antiviral activity, a virus plaque assay using herpes simplex (HS) virus type-1 was carried out. The uptake of poly (I:C) conjugated with fluorescein isothiocyanate (FITC) into the keratinocytes was observed in the presence of LL-37. Immunostaining for TLR3 and LL-37 was performed using skin samples from HS. Results LL-37 and poly (I:C) synergistically induced the expression of IFN-beta in NHEKs. Furthermore, co-stimulation with LL-37 and poly (I:C) significantly decreased the viral plaque numbers compared with poly (I:C) or LL-37 alone. LL-37 enhanced the uptake of FITC-conjugated poly (I:C) into cells. Immunohistochemical analysis demonstrated that the expression of TLR3 and LL-37 is up-regulated in HS lesions. Conclusions Our findings suggest that LL-37 augments the antiviral activity induced by dsRNA in keratinocytes, which may contribute to the innate immune response to cutaneous viral infections such as HS

    Therapeutics potentiating microglial p21-Nrf2 axis can rescue neurodegeneration caused by neuroinflammation

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    神経炎症の抑制を可能にする新規化合物を発⾒ --iPS-ドパミン神経前駆細胞の移植を促進--. 京都大学プレスリリース. 2020-11-16.Neurodegenerative disorders are caused by progressive neuronal loss, and there is no complete treatment available yet. Neuroinflammation is a common feature across neurodegenerative disorders and implicated in the progression of neurodegeneration. Dysregulated activation of microglia causes neuroinflammation and has been highlighted as a treatment target in therapeutic strategies. Here, we identified novel therapeutic candidate ALGERNON2 (altered generation of neurons 2) and demonstrate that ALGERNON2 suppressed the production of proinflammatory cytokines and rescued neurodegeneration in a 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)–induced Parkinson’s disease model. ALGERNON2 stabilized cyclinD1/p21 complex, leading to up-regulation of nuclear factor erythroid 2–related factor 2 (Nrf2), which contributes to antioxidative and anti-inflammatory responses. Notably, ALGERNON2 enhanced neuronal survival in other neuroinflammatory conditions such as the transplantation of induced pluripotent stem cell–derived dopaminergic neurons into murine brains. In conclusion, we present that the microglial potentiation of the p21-Nrf2 pathway can contribute to neuronal survival and provide novel therapeutic potential for neuroinflammation-triggered neurodegeneration

    Homozygous CDA*3 is a major cause of life-threatening toxicities in gemcitabine-treated Japanese cancer patients

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    Among 242 Japanese pancreatic cancer patients, three patients (1.2%) encountered life-threatening toxicities, including myelosuppression, after gemcitabine-based chemotherapies. Two of them carried homozygous CDA*3 (CDA208G>A [Ala70Thr]), and showed extremely low plasma cytidine deaminase activity and gemcitabine clearance. Our results suggest that homozygous *3 is a major factor causing gemcitabine-mediated severe adverse reactions among the Japanese population

    A phase I and pharmacokinetic study of NK105, a paclitaxel-incorporating micellar nanoparticle formulation

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    This phase I study was designed to examine the maximum tolerated dose (MTD), the dose-limiting toxicities (DLTs), the recommended dose (RD) for phase II, and the pharmacokinetics of NK105, a new polymeric micelle carrier system for paclitaxel (PTX). NK105 was administered as a 1-h intravenous infusion every 3 weeks, without antiallergic premedication. The starting dose was 10 mg m−2, and the dose was escalated according to the accelerated titration method. Nineteen patients were recruited. The tumour types treated included pancreatic (n=11), bile duct (n=5), gastric (n=2), and colonic (n=1) cancers. Neutropenia was the most common haematological toxicity. A grade 3 fever developed in one patient given 180 mg m−2. No other grades 3 or 4 nonhaematological toxicities, including neuropathy, was observed during the entire study period. DLTs occurred in two patients given 180 mg m−2 (grade 4 neutropenia lasting for more than 5 days). Thus, this dose was designated as the MTD. Grade 2 hypersensitivity reactions developed in only one patient given 180 mg m−2. A partial response was observed in one patient with pancreatic cancer. The maximum concentration (Cmax) and area under the concentration (AUC) of NK105 were dose dependent. The plasma AUC of NK105 at 150 mg m−2 was approximately 15-fold higher than that of the conventional PTX formulation. NK105 was well tolerated, and the RD for the phase II study was determined to be 150 mg m−2 every 3 weeks. The results of this phase I study warrant further clinical evaluation

    Selective depletion of mouse kidney proximal straight tubule cells causes acute kidney injury

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    The proximal straight tubule (S3 segment) of the kidney is highly susceptible to ischemia and toxic insults but has a remarkable capacity to repair its structure and function. In response to such injuries, complex processes take place to regenerate the epithelial cells of the S3 segment; however, the precise molecular mechanisms of this regeneration are still being investigated. By applying the “toxin receptor mediated cell knockout” method under the control of the S3 segment-specific promoter/enhancer, Gsl5, which drives core 2 β-1,6-N-acetylglucosaminyltransferase gene expression, we established a transgenic mouse line expressing the human diphtheria toxin (DT) receptor only in the S3 segment. The administration of DT to these transgenic mice caused the selective ablation of S3 segment cells in a dose-dependent manner, and transgenic mice exhibited polyuria containing serum albumin and subsequently developed oliguria. An increase in the concentration of blood urea nitrogen was also observed, and the peak BUN levels occurred 3–7 days after DT administration. Histological analysis revealed that the most severe injury occurred in the S3 segments of the proximal tubule, in which tubular cells were exfoliated into the tubular lumen. In addition, aquaporin 7, which is localized exclusively to the S3 segment, was diminished. These results indicate that this transgenic mouse can suffer acute kidney injury (AKI) caused by S3 segment-specific damage after DT administration. This transgenic line offers an excellent model to uncover the mechanisms of AKI and its rapid recovery
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