112 research outputs found

    The pandemic (H1N1) 2009 influenza virus is resistant to mannose-binding lectin

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    <p>Abstract</p> <p>Background</p> <p>Mannose-binding lectin (MBL) is an important component of innate immunity because it promotes bacterial clearance and neutralization of human influenza A viruses. Since a majority of humans have no neutralizing antibody against the pandemic (H1N1) 2009 influenza (pandemic 2009) virus, innate immunity may be crucial and MBL susceptibility may therefore influence viral pathogenesis.</p> <p>Results</p> <p>We examined MBL susceptibility of influenza A viruses and observed that the pandemic 2009 virus was resistant to MBL, whereas all seasonal influenza A viruses tested were susceptible. The mortality of mice infected with a seasonal H1N1 influenza virus was evidently enhanced on transient blockage of MBL activity by simultaneous inoculation of mannan, whereas mannan inoculation had no effect on mice infected with a pandemic 2009 virus. This indicates that MBL protects mice against infection with the seasonal virus but not against that with the pandemic 2009 virus.</p> <p>Conclusions</p> <p>These results indicate that the pandemic 2009 virus is not susceptible to MBL, an important component of innate immunity.</p

    Defective Angiogenesis in the Inflammatory Granulation Tissue in Histidine Decarboxylase–deficient Mice but not in Mast Cell–deficient Mice

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    We have analyzed the role of histamine in the angiogenesis of the granulation tissue in histidine decarboxylase–deficient (HDC−/−) mice, mast cell–deficient mice (WBB6F1-W/WV), and their corresponding wild-type mice (HDC+/+ and WBB6F1+/+). In HDC+/+ mice, subcutaneous implantation of a cotton thread in the dorsum induced granulation tissue formation with angiogenesis, while the topical injection of antivascular endothelial growth factor (VEGF) IgG strongly suppressed them. In HDC−/− mice which showed lower VEGF levels in the granulation tissue, there was notably less angiogenesis and granulation tissue formation than in HDC+/+ mice. The topical injection of histamine or the H2 agonist dimaprit rescued the defective angiogenesis and granulation tissue formation in HDC−/− mice. There was no significant difference in the granulation tissue formation and angiogenesis between WBB6F1-W/WV and WBB6F1+/+ mice. In addition, macrophages in the granulation tissue were found to express HDC. Our findings indicate that histamine derived from nonmast cells plays a significant role in the angiogenesis of the inflammatory granulation tissue

    FGF7 and FGF10 Directly Induce the Apical Ectodermal Ridge in Chick Embryos

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    AbstractDuring vertebrate limb development, the apical ectodermal ridge (AER) plays a vital role in both limb initiation and distal outgrowth of the limb bud. In the early chick embryo the prelimb bud mesoderm induces the AER in the overlying ectoderm. However, the direct inducer of the AER remains unknown. Here we report that FGF7 and FGF10, members of the fibroblast growth factor family, are the best candidates for the direct inducer of the AER. FGF7 induces an ectopic AER in the flank ectoderm of the chick embryo in a different manner from FGF1, -2, and -4 and activates the expression of Fgf8, an AER marker gene, in a cultured flank ectoderm without the mesoderm. Remarkably, FGF7 and FGF10 applied in the back induced an ectopic AER in the dorsal median ectoderm. Our results suggest that FGF7 and FGF10 directly induce the AER in the ectoderm both of the flank and of the dorsal midline and that these two regions have the competence for AER induction. Formation of the AER of the dorsal median ectoderm in the chick embryo is likely to appear as a vestige of the dorsal fin of the ancestors

    Use of intraarticular injections of platelet-rich plasma in the treatment of knee osteoarthritis: A review article

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    Osteoarthritis is one of the most common degenerative conditions affecting knee joint. As our understanding in the disease pathogenesis is evolving, so do the treatment modalities. One of the postulated mechanisms suggests the production of inflammatory cytokines secondary to repeated micro trauma than in turn lead to cartilage damage overtime. Cartilage being avascular structure has limited potential for repair. Based on this, recent studies have been focusing on stimulating cartilage-healing process by growth factors. This is where platelet-rich plasma comes in to light. Literature is showing promising results of platelet-rich plasma in treating knee osteoarthritis. In this review we have discussed the preparation, composition, classification, uses of platelet-rich plasma as well as evidence for its efficacy and complications

    KCNJ13 Gene Deletion Impairs Cell Alignment and Phagocytosis in Retinal Pigment Epithelium Derived from Human-Induced Pluripotent Stem Cells

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    Purpose: The purpose of this study was to establish and analyze a cell model of Leber congenital amaurosis type 16 (LCA16), which is caused by mutations in the KCNJ13 gene encoding Kir7.1, an inward-rectifying potassium ion channel. Methods: The two guide RNAs specific to the target sites in the KCNJ13 gene were designed and KCNJ13 knock-out (KO) human-induced pluripotent stem cells (hiPSCs) were generated using the CRISPR/Cas9 system. The KCNJ13-KO hiPSCs were differentiated into retinal pigment epithelial cells (hiPSC-RPEs). The KCNJ13-KO in hiPSC-RPEs was confirmed by immunostaining. Phagocytic activity of hiPSC-RPEs was assessed using the uptake of fluorescently labeled porcine photoreceptor outer segments (POSs). Phagocytosis-related genes in RPE cells were assessed by quantitative polymerase chain reaction. Results: Most of the translated region of the KCNJ13 gene was deleted in the KCNJ13-KO hiPSCs by the CRISPR/Cas9 system, and this confirmed that the Kir7.1 protein was not present in RPE cells induced from the hiPSCs. Expression of RPE marker genes such as BEST1 and CRALBP was retained in the wild-type (WT) and in the KCNJ13-KO hiPSC-RPE cells. However, phagocytic activity and expression of phagocytosis-related genes in the KCNJ13-null hiPSC-RPE cells were significantly reduced compared to those of WT. Conclusions: We succeeded in generating an RPE model of LCA16 using hiPSCs. We suggest that Kir7.1 is required for phagocytosis of POSs by RPE cells and that impaired phagocytosis in the absence of Kir7.1 would be involved in the retinal degeneration found in LCA16

    Novel antiviral activity of neuraminidase inhibitors against an avian influenza a virus

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    <p>Abstract</p> <p>Background</p> <p>Neuraminidase (NA) inhibitors used for influenza therapy are believed to prevent the release of progeny virus from the surface of an infected cell. In this study, we found that NA inhibitors have a novel antiviral function against an avian influenza virus.</p> <p>Results</p> <p>Madin-Darby canine kidney cells, commonly used for the isolation and propagation of the influenza virus, were infected with an avian influenza viral strain A/chicken/German/N/49(H10N7) (H10/chicken) or a human influenza viral strain A/Osaka/981/98(H3N2) (H3/Osaka) virus. Cells were incubated in a medium without or with a NA inhibitor, oseltamivir carboxylate (GS4071), from 1 to 13 h post infection (p.i.). Infected cells were washed 12 h p.i. to remove GS4071, incubated for 1 h without GS4071, and assayed for virus production. Incubation with GS4071 decreased the production of infectious viruses. When H10/chicken virus-infected cells were incubated with GS4071 from 12 to 13 h p.i. (i.e., 1 h before the virus production assay), the inhibitory effect was clearly observed, however, the same was not evident for H3/Osaka virus-infected cells. Furthermore, viral protein synthesis in infected cells was not affected by GS4071. Using a scanning electron microscope, many single spherical buds were observed on the surface of H3/Osaka virus-infected cells incubated without GS4071, whereas many aggregated particles were observed on the surface of cells incubated with GS4071. However, many long tubular virus-like structures, with no aggregated particles, were observed on the surface of H10/chicken virus-infected cells incubated with GS4071. The same results were obtained when another NA inhibitor, zanamivir, was used.</p> <p>Conclusions</p> <p>These results indicate that NA inhibitors interfered with virus particle formation in the H10/chicken virus-infected cells, in which the inhibitor caused the formation of long tubular virus-like structures instead of spherical virus particles.</p

    Non-transgenic genome modifications in a hemimetabolous insect using zinc-finger and TAL effector nucleases

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    Hemimetabolous, or incompletely metamorphosing, insects are phylogenetically relatively basal and comprise many pests. However, the absence of a sophisticated genetic model system, or targeted gene-manipulation system, has limited research on hemimetabolous species. Here we use zinc-finger nuclease and transcription activator-like effector nuclease technologies to produce genetic knockouts in the hemimetabolous insect Gryllus bimaculatus. Following the microinjection of mRNAs encoding zinc-finger nucleases or transcription activator-like effector nucleases into cricket embryos, targeting of a transgene or endogenous gene results in sequence-specific mutations. Up to 48% of founder animals transmit disrupted gene alleles after zinc-finger nucleases microinjection compared with 17% after microinjection of transcription activator-like effector nucleases. Heterozygous offspring is selected using mutation detection assays that use a Surveyor (Cel-I) nuclease, and subsequent sibling crosses create homozygous knockout crickets. This approach is independent from a mutant phenotype or the genetic tractability of the organism of interest and can potentially be applied to manage insect pests using a non-transgenic strategy. © 2012 Macmillan Publishers Limited. All rights reserved

    Factor structure of the Hospital Anxiety and Depression Scale in Japanese psychiatric outpatient and student populations

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    <p>Abstract</p> <p>Background</p> <p>The Hospital Anxiety and Depression Scale (HADS) is a common screening instrument excluding somatic symptoms of depression and anxiety, but previous studies have reported inconsistencies of its factor structure. The construct validity of the Japanese version of the HADS has yet to be reported. To examine the factor structure of the HADS in a Japanese population is needed.</p> <p>Methods</p> <p>Exploratory and confirmatory factor analyses were conducted in the combined data of 408 psychiatric outpatients and 1069 undergraduate students. The data pool was randomly split in half for a cross validation. An exploratory factor analysis was performed on one half of the data, and the fitness of the plausible model was examined in the other half of the data using a confirmatory factor analysis. Simultaneous multi-group analyses between the subgroups (outpatients vs. students, and men vs. women) were subsequently conducted.</p> <p>Results</p> <p>A two-factor model where items 6 and 7 had dual loadings was supported. These factors were interpreted as reflecting anxiety and depression. Item 10 showed low contributions to both of the factors. Simultaneous multi-group analyses indicated a factor pattern stability across the subgroups.</p> <p>Conclusion</p> <p>The Japanese version of HADS indicated good factorial validity in our samples. However, ambiguous wording of item 7 should be clarified in future revisions.</p
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