99 research outputs found

    Pathogenic analysis of the pandemic 2009 H1N1 influenza A viruses in ferrets

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    The pandemic 2009 H1N1 influenza A virus emerged in humans and caused the first influenza pandemic of the 21st century. Mexican isolates, A/Mexico/4108/2009 (H1N1) (Mex4108) and A/Mexico/InDRE4478/2009 (H1N1) (Mex4487) derived from a mild case and from a cluster of severe cases, showed heterogeneity in virulence in a cynomolgus macaque model. To compare the more pathogenic differences, we generated recombinant viruses and compared their virulence in ferrets. Ferrets infected with recombinant Mex4487 displayed a slightly higher rate of viral replication and severe pneumonia in the early stage of infection. In contrast, prolonged lower virus shedding of recombinant Mex4108 than that of recombinant Mex4487 was detected in throat swabs. Thus, Mex4487 induces severe pneumonia in infected individuals, whereas Mex4108 might have wide-spreading potential with mild disease

    Appearance of renal hemorrhage in adult mice after inoculation of patient-derived hantavirus

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    Background: Hemorrhagic fever with renal syndrome (HFRS) caused by hantavirus infection is characterized by fever, renal dysfunction and hemorrhage. An animal model mimicking symptoms of HFRS remains to be established. In this study, we evaluated the pathogenicity of an HFRS patient-derived Hantaan virus (HTNV) in adult mice. Methods: Five clones of HTNV strain KHF 83-61 BL (KHFV) that was derived from blood of an HFRS patient were obtained by plaque cloning. The pathogenicity of the virus clones was evaluated by using 6-week-old female BALB/c mice. Sequence analysis of the viral genome was performed by conventional methods. Results: All of the mice intravenously inoculated with KHFV clone (cl)-1, -2, -3 and -5 showed signs of disease such as transient body weight loss, ruffled fur, reduced activity and remarkably prominent hemorrhage in the renal medulla at 6 to 9 days post-inoculation (dpi) and then recovered. In contrast, mice intravenously inoculated with KHFV cl-4 did not show any signs of disease. We selected KHFV cl-5 and cl-4 as representative of high-pathogenic and low-pathogenic clones, respectively. Quantities of viral RNA in kidneys of KHFV cl-5-infected mice were larger than those in KHFV cl-4-infected mice at any time point examined (3, 6, 9 and 12 dpi). The quantities of viral RNA of KHFV cl-5 and cl-4 peaked at 3 dpi, which was before the onset of disease. Sequence analysis revealed that the amino acid at position 417 in the glycoprotein Gn was the sole difference in viral proteins between KHFV cl-5 and cl-4. The result suggests that amino acid at position 417 in Gn is related to the difference in pathogenicity between KHFV cl-5 and cl-4. When the inoculum of KHFV cl-5 was pretreated with a neutralizing antibody against HTNV strain 76-118, which belongs to the same serotype as KHFV clones, mice did not show any signs of disease, confirming that the disease was caused by KHFV infection. Conclusion: We found that an HFRS patient-derived HTNV caused renal hemorrhage in adult mice. We anticipate that this infection model will be a valuable tool for understanding the pathogenesis of HFRS

    A Replicating Cytomegalovirus-Based Vaccine Encoding a Single Ebola Virus Nucleoprotein CTL Epitope Confers Protection against Ebola Virus

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    Human outbreaks of hemorrhagic disease caused by Ebola virus (EBOV) are a serious health concern in Central Africa. Great apes (gorillas/chimpanzees) are an important source of EBOV transmission to humans. Candidate EBOV vaccines do not spread from the initial vaccinee. In addition to being highly immunogenic, vaccines based on the cytomegalovirus (CMV) platform have the unique potential to re-infect and disseminate through target populations. To explore the utility of CMV-based vaccines against EBOV, we constructed a mouse CMV (MCMV) vector expressing a region of nucleoprotein (NP) of Zaire ebolavirus (ZEBOV) (MCMV/ZEBOV-NPCTL). MCMV/ZEBOV-NPCTL induced high levels of long-lasting CD8+ T cells against ZEBOV NP in mice. Importantly, all vaccinated animals were protected against lethal ZEBOV challenge. The absence of ZEBOV neutralizing and only low, sporadic levels of total anti-ZEBOV IgG antibodies in protected animals prior to ZEBOV challenge indicate a role, albeit perhaps not exclusive, for CD8+ T cells in mediating protection. This study demonstrates the ability of a CMV-based vaccine approach to protect against ZEBOV, and provides a ‘proof-of-concept’ for the potential for a ‘disseminating’ CMV-based EBOV vaccine to prevent EBOV transmission in wild animal populations

    Developmental changes in facial expression recognition in Japanese school-age children

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    Purpose : Facial expressions hold abundant information and play a central part in communication. In daily life, we must construct amicable interpersonal relationships by communicating through verbal and nonverbal behaviors. While school-age is a period of rapid social growth, few studies exist that study developmental changes in facial expression recognition during this age. This study investigated developmental changes in facial expression recognition by examining observers’ gaze on others’ expressions. Subjects : 87 school-age children from first to sixth grade (41 boys, 46 girls). Method : The Tobii T60 Eye-tracker(Tobii Technologies, Sweden) was used to gauge eye movement during a task of matching pre-instructed emotion words and facial expressions images (neutral, angry, happy, surprised, sad, disgusted) presented on a monitor fixed at a distance of 50 cm. Results : In the task of matching the six facial expression images and emotion words, the mid- and higher-grade children answered more accurately than the lower-grade children in matching four expressions, excluding neutral and happy. For fixation time and fixation count, the lower-grade children scored lower than other grade children, gazing on all facial expressions significantly fewer times and for shorter periods. Conclusion : It is guessed that the stage from lower grades to middle grades is a turning point in facial recognition

    イッパン シャカイジン ニオケル ハッタツ ショウガイ ニ カンスル ヨウゴ ノ ニンチド

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    We examined the familiarity degree of the terms that concern the developmental disability in general public and also surveyed their source of information. The participants were 50 commoners, 4 females and 46 males. Many of them were age of 30s. In the questionnaire, there were 20 items including “developmental disability”, “autism”, “learning disability”, “coordinator of special needs education” and so on. We requested participants to evaluate which level a familiarity degree in each word was. Excluding the two subjects’ data because there were blanks, we analyzed 48 people’s data. In the results, it was shown that most items concerning developmental disability were unfamiliar to general public. This result is different from other research conducted in teachers or welfare workers. It must be examined in other age groups to check whether this tendency is common. We concluded that it is necessary to improve the way of enlightenment for understanding developmental disability, not only for specialists but also for general public

    Genetic Predisposition To Acquire a Polybasic Cleavage Site for Highly Pathogenic Avian Influenza Virus Hemagglutinin

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    Highly pathogenic avian influenza viruses with H5 and H7 hemagglutinin (HA) subtypes evolve from low-pathogenic precursors through the acquisition of multiple basic amino acid residues at the HA cleavage site. Although this mechanism has been observed to occur naturally only in these HA subtypes, little is known about the genetic basis for the acquisition of the polybasic HA cleavage site. Here we show that consecutive adenine residues and a stem-loop structure, which are frequently found in the viral RNA region encoding amino acids around the cleavage site of low-pathogenic H5 and H7 viruses isolated from waterfowl reservoirs, are important for nucleotide insertions into this RNA region. A reporter assay to detect nontemplated nucleotide insertions and deep-sequencing analysis of viral RNAs revealed that an increased number of adenine residues and enlarged stem-loop structure in the RNA region accelerated the multiple adenine and/or guanine insertions required to create codons for basic amino acids. Interestingly, nucleotide insertions associated with the HA cleavage site motif were not observed principally in the viral RNA of other subtypes tested (H1, H2, H3, and H4). Our findings suggest that the RNA editing-like activity is the key mechanism for nucleotide insertions, providing a clue as to why the acquisition of the polybasic HA cleavage site is restricted to the particular HA subtypes. IMPORTANCE Influenza A viruses are divided into subtypes based on the antigenicity of the viral surface glycoproteins hemagglutinin (HA) and neuraminidase. Of the 16 HA subtypes (H1 to -16) maintained in waterfowl reservoirs of influenza A viruses, H5 and H7 viruses often become highly pathogenic through the acquisition of multiple basic amino acid residues at the HA cleavage site. Although this mechanism has been known since the 1980s, the genetic basis for nucleotide insertions has remained unclear. This study shows the potential role of the viral RNA secondary structure for nucleotide insertions and demonstrates a key mechanism explaining why the acquisition of the polybasic HA cleavage site is restricted to particular HA subtypes in nature. Our findings will contribute to better understanding of the ecology of influenza A viruses and will also be useful for the development of genetically modified vaccines against H5 and H7 influenza A viruses with increased stability

    Mutual Antagonism between the Ebola Virus VP35 Protein and the RIG-I Activator PACT Determines Infection Outcome

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    SummaryThe cytoplasmic pattern recognition receptor RIG-I is activated by viral RNA and induces type I IFN responses to control viral replication. The cellular dsRNA binding protein PACT can also activate RIG-I. To counteract innate antiviral responses, some viruses, including Ebola virus (EBOV), encode proteins that antagonize RIG-I signaling. Here, we show that EBOV VP35 inhibits PACT-induced RIG-I ATPase activity in a dose-dependent manner. The interaction of PACT with RIG-I is disrupted by wild-type VP35, but not by VP35 mutants that are unable to bind PACT. In addition, PACT-VP35 interaction impairs the association between VP35 and the viral polymerase, thereby diminishing viral RNA synthesis and modulating EBOV replication. PACT-deficient cells are defective in IFN induction and are insensitive to VP35 function. These data support a model in which the VP35-PACT interaction is mutually antagonistic and plays a fundamental role in determining the outcome of EBOV infection

    ガッキュウ タンニン ガ オコナウ ヨミカキ ニ ツマズキ オ シメス ショウガッコウ 1ネンセイ エノ スクリーニング ケンサ ノ ココロミ

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    The purpose of this study was early detection of difficulties in reading and writing at first grade children, so we examined the screening methods that was conducted by a class teacher. Participants were 44 first grade children. There were primary test and the second test, and the former contents were as follows ;(1) symptoms checklist in reading/writing, (2)(3) hiragana reading/writing test, and (4)(5) visual cognition test. Eight children were selected to the second test that used WISC−IV and 4 kinds of reading tests. All of them did not have the intellectual disabilities, but in reading test, their score was a deviation level. In time of reading, half of them got more than 2 standard deviation level score. The evaluation of the teacher for the test that we used in this study was high except for the visual cognitive test. The findings of this study suggest that assessment conducted by a class teacher is useful to give multi viewpoint of the observation to the detection of the child who may have difficulties in reading and writing

    Characterization of H5N1 highly pathogenic avian influenza virus strains isolated from migratory waterfowl in Mongolia on the way back from the southern Asia to their northern territory

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    AbstractH5N1 highly pathogenic avian influenza (HPAI) viruses were isolated from dead wild waterfowl at Khunt, Erkhel, Doityn Tsagaan, Doroo, and Ganga Lakes in Mongolia in July 2005, May 2006, May 2009, July 2009, and May 2010, respectively. The isolates in 2005 and 2006 were classified into genetic clade 2.2, and those in 2009 and 2010 into clade 2.3.2. A/whooper swan/Mongolia/6/2009 (H5N1) experimentally infected ducks and replicated systemically with higher mortality than that of the isolates in 2005 and 2006. Intensive surveillance of avian influenza in migratory waterfowl flying from their nesting lakes in Siberia to Mongolia in every autumn indicate that HPAI viruses have not perpetuated at their nesting lakes until 2009. The present results demonstrate that wild waterfowl were sporadically infected with H5N1 HPAI viruses prevailing in domestic poultry in the southern Asia and died in Mongolia on the way back to their northern territory in spring
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