106 research outputs found

    Different Outcomes of Experimental Hepatitis E Virus Infection in Diverse Mouse Strains, Wistar Rats, and Rabbits

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    Hepatitis E virus (HEV) is the causative agent of acute hepatitis E in humans in developing countries, but autochthonous cases of zoonotic genotype 3 (HEV-3) infection also occur in industrialized countries. In contrast to swine, rats, and rabbits, natural HEV infections in mice have not yet been demonstrated. The pig represents a well-established large animal model for HEV-3 infection, but a suitable small animal model mimicking natural HEV-3 infection is currently missing. Therefore, we experimentally inoculated C57BL/6 mice (wild-type, IFNAR−/−, CD4−/−, CD8−/−) and BALB/c nude (nu/nu) mice, Wistar rats, and European rabbits with a wild boar-derived HEV-3 strain and monitored virus replication and shedding, as well as humoral immune responses. HEV RNA and anti-HEV antibodies were detected in one and two out of eight of the rats and all rabbits inoculated, respectively, but not in any of the mouse strains tested. Remarkably, immunosuppressive dexamethasone treatment of rats did not enhance their susceptibility to HEV infection. In rabbits, immunization with recombinant HEV-3 and ratHEV capsid proteins induced protection against HEV-3 challenge. In conclusion, the rabbit model for HEV-3 infection may serve as a suitable alternative to the non-human primate and swine models, and as an appropriate basis for vaccine evaluation studies

    A Medicinal Herb Scutellaria lateriflora Inhibits PrP Replication in vitro and Delays the Onset of Prion Disease in Mice

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    Transmissible spongiform encephalopathies (TSE) are characterized by the misfolding of the host encoded prion protein (PrPC) into a pathogenic isoform (PrPSc) which leads to the accumulation of β-sheet-rich fibrils and subsequent loss of neurons and synaptic functions. Although many compounds have been identified which inhibit accumulation or dissolve fibrils and aggregates in vitro there is no therapeutic treatment to stop these progressive neurodegenerative diseases. Here we describe the effects of the traditional medicinal herb Scutellaria lateriflora (S. lateriflora) and its natural compounds, the flavonoids baicalein and baicalin, on the development of prion disease using in vitro and in vivo models. S. lateriflora extract as well as both constituents reduced the PrPres accumulation in scrapie-infected cell cultures and cell-free conversion assays and lead to the destabilization of pre-existing PrPSc fibrils. Moreover, tea prepared from S. lateriflora, prolonged significantly the incubation time of scrapie-infected mice upon oral treatment. Therefore S. lateriflora extracts as well as the individual compounds can be considered as promising candidates for the development of new therapeutic drugs against TSEs and other neurodegenerative diseases like Alzheimer’s and Parkinson’s disease

    Evidence for West Nile Virus and Usutu Virus Infections in Wild and Resident Birds in Germany, 2017 and 2018

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    Wild birds play an important role as reservoir hosts and vectors for zoonotic arboviruses and foster their spread. Usutu virus (USUV) has been circulating endemically in Germany since 2011, while West Nile virus (WNV) was first diagnosed in several bird species and horses in 2018. In 2017 and 2018, we screened 1709 live wild and zoo birds with real-time polymerase chain reaction and serological assays. Moreover, organ samples from bird carcasses submitted in 2017 were investigated. Overall, 57 blood samples of the live birds (2017 and 2018), and 100 organ samples of dead birds (2017) were positive for USUV-RNA, while no WNV-RNA-positive sample was found. Phylogenetic analysis revealed the first detection of USUV lineage Europe 2 in Germany and the spread of USUV lineages Europe 3 and Africa 3 towards Northern Germany. USUV antibody prevalence rates were high in Eastern Germany in both years. On the contrary, in Northern Germany, high seroprevalence rates were first detected in 2018, with the first emergence of USUV in this region. Interestingly, high WNV-specific neutralizing antibody titers were observed in resident and short-distance migratory birds in Eastern Germany in 2018, indicating the first signs of a local WNV circulation

    Hepatitis E virus: Efficacy of pasteurization of plasma‐derived VWF/FVIII concentrate determined by pig bioassay

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    Background Hepatitis E virus (HEV) is the leading cause of acute hepatitis throughout the world. Increasing blood component transfusion-associated HEV infections highlight the need for reliable virus inactivation procedures for plasma derivatives from pooled plasma donations. Study Design and Methods An animal infection study was conducted to evaluate the efficiency of HEV inactivation by pasteurization during the manufacturing process of the von Willebrand Factor/Factor VIII (VWF/FVIII) concentrate Haemate P/Humate-P (CSL Behring, Marburg, Germany). For this purpose, groups of pigs were inoculated with stabilized VWF/FVIII intermediate spiked with HEV-positive liver homogenate and exposed to increasing incubation times of 0, 3, 6, and 10 h at 60 degrees C. Animals were evaluated for virus replication over 27 days and in a subsequent trial over 92 days. Results Virus replication was detected in animals up to the 6-h pasteurization group. In contrast, pasteurization for 10 h did not reveal virus detection when the observation period was 27 days. In an additional experiment using the 10-h pasteurized material, two individuals started virus excretion and seroconverted when the observation period was extended to 92 days. Based on the total infection rate (2 of 12) of the animals inoculated with the sample pasteurized for 10 h, a virus reduction factor of at least 4.7 log(10) is calculated. Conclusion This study demonstrates that pasteurization at 60 degrees C for 10 h of an HEV-positive plasma derivative leads to the effective reduction of infectivity, resulting in a VWF/FVIII product with an appropriate margin of safety for HEV

    Sleep Health Issues for Children with FASD: Clinical Considerations

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    This article describes the combined clinical experience of a multidisciplinary group of professionals on the sleep disturbances of children with fetal alcohol spectrum disorders (FASD) focusing on sleep hygiene interventions. Such practical and comprehensive information is not available in the literature. Severe, persistent sleep difficulties are frequently associated with this condition but few health professionals are familiar with both FASD and sleep disorders. The sleep promotion techniques used for typical children are less suitable for children with FASD who need individually designed interventions. The types, causes, and adverse effects of sleep disorders, the modification of environment, scheduling and preparation for sleep, and sleep health for their caregivers are discussed. It is our hope that parents and also researchers, who are interested in the sleep disorders of children with FASD, will benefit from this presentation and that this discussion will stimulate much needed evidence-based research

    Instructional Models for Course-Based Research Experience (CRE) Teaching

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    The course-based research experience (CRE) with its documented educational benefits is increasingly being implemented in science, technology, engineering, and mathematics education. This article reports on a study that was done over a period of 3 years to explicate the instructional processes involved in teaching an undergraduate CRE. One hundred and two instructors from the established and large multi-institutional SEA-PHAGES program were surveyed for their understanding of the aims and practices of CRE teaching. This was followed by large-scale feedback sessions with the cohort of instructors at the annual SEA Faculty Meeting and subsequently with a small focus group of expert CRE instructors. Using a qualitative content analysis approach, the survey data were analyzed for the aims of inquiry instruction and pedagogical practices used to achieve these goals. The results characterize CRE inquiry teaching as involving three instructional models: 1) being a scientist and generating data; 2) teaching procedural knowledge; and 3) fostering project ownership. Each of these models is explicated and visualized in terms of the specific pedagogical practices and their relationships. The models present a complex picture of the ways in which CRE instruction is conducted on a daily basis and can inform instructors and institutions new to CRE teaching

    Effect of Q211 and K222 PRNP polymorphic variants in the susceptibility of goats to oral infection with Goat-BSE

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    Background. The prion protein-encoding gene (PRNP) is one of the major determinants for scrapie occurrence in sheep and goats. However, its effect on bovine spongiform encephalopathy (BSE) transmission to goats is not clear. Methods. Goats harboring wild-type, R/Q211 or Q/K222 PRNP genotypes were orally inoculated with a goat-BSE isolate to assess their relative susceptibility to BSE infection. Goats were killed at different time points during the incubation period and after the onset of clinical signs, and their brains as well as several peripheral tissues were analyzed for the accumulation of pathological prion protein (PrPSc) and prion infectivity by mouse bioassay. Results. R/Q211 goats displayed delayed clinical signs compared with wild-type goats. Deposits of PrPSc were detected only in brain, whereas infectivity was present in peripheral tissues too. In contrast, none of the Q/K222 goats showed any evidence of clinical prion disease. No PrPSc accumulation was observed in their brains or peripheral tissues, but very low infectivity was detected in some tissues very long after inoculation (44–45 months). Conclusions. These results demonstrate that transmission of goat BSE is genotype dependent, and they highlight the pivotal protective effect of the K222 PRNP variant in the oral susceptibility of goats to BSE. <br/

    A Phase I Double Blind, Placebo-Controlled, Randomized Study of a Multigenic HIV-1 Adenovirus Subtype 35 Vector Vaccine in Healthy Uninfected Adults

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    <div><h3>Background</h3><p>We conducted a phase I, randomized, double-blind, placebo-controlled trial to assess the safety and immunogenicity of escalating doses of two recombinant replication defective adenovirus serotype 35 (Ad35) vectors containing gag, reverse transcriptase, integrase and nef (Ad35-GRIN) and env (Ad35-ENV), both derived from HIV-1 subtype A isolates. The trial enrolled 56 healthy HIV-uninfected adults.</p> <h3>Methods</h3><p>Ad35-GRIN/ENV (Ad35-GRIN and Ad35-ENV mixed in the same vial in equal proportions) or Ad35-GRIN was administered intramuscularly at 0 and 6 months. Participants were randomized to receive either vaccine or placebo (10/4 per group, respectively) within one of four dosage groups: Ad35-GRIN/ENV 2×10<sup>9</sup> (A), 2×10<sup>10</sup> (B), 2×10<sup>11</sup> (C), or Ad35-GRIN 1×10<sup>10</sup> (D) viral particles.</p> <h3>Results</h3><p>No vaccine-related serious adverse event was reported. Reactogenicity events reported were dose-dependent, mostly mild or moderate, some severe in Group C volunteers, all transient and resolving spontaneously. IFN-γ ELISPOT responses to any vaccine antigen were detected in 50, 56, 70 and 90% after the first vaccination, and in 75, 100, 88 and 86% of Groups A–D vaccine recipients after the second vaccination, respectively. The median spot forming cells (SFC) per 10<sup>6</sup> PBMC to any antigen was 78–139 across Groups A–C and 158–174 in Group D, after each of the vaccinations with a maximum of 2991 SFC. Four to five HIV proteins were commonly recognized across all the groups and over multiple timepoints. CD4+ and CD8+ T-cell responses were polyfunctional. Env antibodies were detected in all Group A–C vaccinees and Gag antibodies in most vaccinees after the second immunization. Ad35 neutralizing titers remained low after the second vaccination.</p> <h3>Conclusion/Significance</h3><p>Ad35-GRIN/ENV reactogenicity was dose-related. HIV-specific cellular and humoral responses were seen in the majority of volunteers immunized with Ad35-GRIN/ENV or Ad35-GRIN and increased after the second vaccination. T-cell responses were broad and polyfunctional.</p> <h3>Trial Registration</h3><p>ClinicalTrials.gov <a href="http://clinicaltrials.gov/ct2/results?term=NCT00851383">NCT00851383</a></p> </div
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