92 research outputs found

    An outbreak of aseptic meningitis due to echovirus 30 associated with attending school and swimming in pools

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    Summary Objectives To identify the risk factors of an outbreak of meningitis associated with echovirus 30-infection that occurred in Rome, Italy, in late 1997 among children from two different schools. Methods A case-control study was carried out. A case was defined as a child from either of the two schools, A or B, who presented meningitis-like (fever, headache and vomiting), diarrhea, or respiratory tract symptoms. All asymptomatic students were included in the analysis as controls. Results Among 446 pupils (80%) who answered the questionnaire, 68 met the case definition. Twenty pupils developed a meningitis-like illness. Echovirus 30 was isolated from cerebrospinal fluid (CSF) in four and from stools in six. Forty-eight pupils reported other symptoms. The attack rate was 10.8% in school A and 0.8% in school B for meningitis-like illness; it was 12% and 10%, respectively, for other enterovirus-like illnesses. The risk of meningitis-like illness was higher among children attending school A (crude OR=14.9; 95% CI=4.3–52.1), among children using any public pool (OR=3.8; 95% CI=1.5–9.9) and those using an outside swimming pool X (OR=13.4; 95% CI=2.7–65.8 versus no swimming pool and OR=8.3; 95% CI=1.1–62.6 versus other pools). The epidemic curve appears to suggest a person-to-person transmission. Conclusions The epidemic occurred by person-to-person transmission in a number of classrooms and at swimming pool X

    Defining a Novel Role for the Coxsackievirus and Adenovirus Receptor in Human Adenovirus Serotype 5 Transduction In Vitro in the Presence of Mouse Serum

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    Human adenoviral serotype 5 (HAdV-5) vectors have predominantly hepatic tropism when delivered intravascularly, resulting in immune activation and toxicity. Coagulation FX binding to HAdV-5 mediates liver transduction and provides protection from virion neutralisation in mice. FX is dispensable for liver transduction in mice lacking IgM antibodies or complement, suggesting alternative transduction pathways exist. To identify novel factor(s) mediating HAdV-5 FX-independent entry, we investigated HAdV-5 transduction in vitro in the presence of serum from immunocompetent C57BL/6 or immunocompromised mice lacking IgM antibodies (Rag 2-/- and NSG). Sera from all three mouse strains enhanced HAdV-5 transduction of A549 cells. While inhibition of HAdV-5:FX interaction with X-bp inhibited transduction in the presence of C57BL/6 serum, it had negligible effect on the enhanced transduction observed in the presence of Rag 2-/- or NSG serum. Rag 2-/- serum also enhanced transduction of the FX-binding deficient AdT*. Interestingly, Rag 2-/- serum enhanced HAdV-5 transduction in a FX-independent manner in CHO-CAR and SKOV3-CAR cells. Additionally, blockade of CAR with soluble HAdV-5 fiber knob inhibited mouse serum-enhanced transduction in A549 cells, suggesting a potential role for CAR. Transduction of HAdV-5 KO1 and HAdV-5/F35 (CAR-binding deficient) in the presence of Rag 2-/- serum was equivalent to that of HAdV-5, indicating that direct interaction between HAdV-5 and CAR is not required. These data suggest that FX may protect HAdV-5 from neutralization but has minimal contribution to HAdV-5 transduction in the presence of immunocompromised mouse serum. Alternatively, transduction occurs via an unidentified mouse serum protein capable of bridging HAdV-5 to CAR

    Label-free protein detection based on the heat-transfer method-a case study with the peanut allergen Ara h 1 and aptamer-based synthetic receptors

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    © 2015 American Chemical Society. Aptamers are an emerging class of molecules that, because of the development of the systematic evolution of ligands by exponential enrichment (SELEX) process, can recognize virtually every target ranging from ions, to proteins, and even whole cells. Although there are many techniques capable of detecting template molecules with aptamer-based systems with high specificity and selectivity, they lack the possibility of integrating them into a compact and portable biosensor setup. Therefore, we will present the heat-transfer method (HTM) as an interesting alternative because this offers detection in a fast and low-cost manner and has the possibility of performing experiments with a fully integrated device. This concept has been demonstrated for a variety of applications including DNA mutation analysis and screening of cancer cells. To the best our knowledge, this is the first report on HTM-based detection of proteins, in this case specifically with aptamer-type receptors. For proof-of-principle purposes, measurements will be performed with the peanut allergen Ara h 1 and results indicate detection limits in the lower nanomolar regime in buffer liquid. As a first proof-of-application, spiked Ara h 1 solutions will be studied in a food matrix of dissolved peanut butter. Reference experiments with the quartz-crystal microbalance will allow for an estimate of the areal density of aptamer molecules on the sensor-chip surface

    Comparison of the reactogenicity and immunogenicity of a two injection combined high-dose hepatitis A and hepatitis B vaccine to those of Twinrix

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    Twinrix (SmithKline Beecham Biologicals) is a combined hepatitis A and B vaccine licensed with a three-dose schedule. A two-dose combined hepatitis A and B vaccine would facilitate immunisation programs. In this prospective study, 100 healthy adults, aged between 18 and 40, were enrolled. A first group of 50 was given a high-dose vaccine at month 0 and 6. A second group of 50 received Twinrix at month 0, 1 and 6.The reactogenicity was assessed after each vaccine dose. There were no severe local adverse events. Seven severe systemic reactions occurred, of which five were fatigue, one was headache and one consist in gastrointestinal symptoms. They all resolved during the 4-day follow-up period. One serious general adverse event was reported, but was clearly unrelated to the vaccine. Thus, both vaccines were well tolerated.The immunogenicity was evaluated by testing for anti-HBs and anti-HAV antibodies. Seroconversion rates and geometric mean titres (GMTs) were compared. At month 7, the anti-HAV GMTs were higher in the high-dose group than in the Twinrix group and, inversely, the anti-HBs GMTs were slightly higher in the Twinrix group than in the high-dose group. At month 7, all subjects in both groups were positive for anti-HAV. All subjects in the high-dose group and 97.6% subjects in the Twinrix group had seroconverted for anti-HBs. Therefore, it can be concluded that with two injections of the high-dose hepatitis A and B vaccine, 6 months apart, a similar immune response can be obtained as induced with three doses of Twinrix at months 0, 1 and 6

    Combining electrochemical impedance spectroscopy and surface plasmon resonance into one simultaneous read-out system for the detection of surface interactions

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    In this article we describe the integration of impedance spectroscopy (EIS) and surface plasmon resonance (SPR) into one surface analytic device. A polydimethylsiloxane (PDMS) flow cell is created, matching the dimensions of a commercially available sensor chip used for SPR measurements. This flow cell allowed simultaneous measurements between an EIS and a SPR setup. After a successful integration, a proof of principle study was conducted to investigate any signs of interference between the two systems during a measurement. The flow cell was rinsed with 10 mM Tris-HCl and 1x PBS buffer in an alternating manner, while impedance and shifts of the resonance angle were monitored. After achieving a successful proof of principle, a usability test was conducted. It was assessed whether simultaneous detection occurred when: (i) Protein A is adsorbed to the gold surface of the chip; (ii) The non-occupied zone is blocked with BSA molecules and (iii) IgG1 is bound to the Protein A. The results indicate a successful merge between SPR and EIS
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