467 research outputs found

    Entry pathways of herpes simplex virus type 1 into human keratinocytes are dynamin- and cholesterol-dependent

    Get PDF
    Herpes simplex virus type 1 (HSV-1) can enter cells via endocytic pathways or direct fusion at the plasma membrane depending on the cell line and receptor(s). Most studies into virus entry have used cultured fibroblasts but since keratinocytes represent the primary entry site for HSV-1 infection in its human host, we initiated studies to characterize the entry pathway of HSV-1 into human keratinocytes. Electron microscopy studies visualized free capsids in the cytoplasm and enveloped virus particles in vesicles suggesting viral uptake both by direct fusion at the plasma membrane and by endocytic vesicles. The ratio of the two entry modes differed in primary human keratinocytes and in the keratinocyte cell line HaCaT. Inhibitor studies further support a role for endocytosis during HSV-1 entry. Infection was inhibited by the cholesterol-sequestering drug methyl-beta-cyclodextrin, which demonstrates the requirement for host cholesterol during virus entry. Since the dynamin-specific inhibitor dynasore and overexpression of a dominant-negative dynamin mutant blocked infection, we conclude that the entry pathways into keratinocytes are dynamin-mediated. Electron microscopy studies confirmed that virus uptake is completely blocked when the GTPase activity of dynamin is inhibited. Ex vivo infection of murine epidermis that was treated with dynasore further supports the essential role of dynamin during entry into the epithelium. Thus, we conclude that HSV-1 can enter human keratinocytes by alternative entry pathways that require dynamin and host cholesterol

    Comparative assessment of young learners' foreign language competence in three Eastern European countries

    Get PDF
    This paper concerns teacher practices in, and beliefs about, the assessment of young learners' progress in English in three Eastern European countries (Slovenia, Croatia, and the Czech Republic). The central part of the paper focuses on an international project involving empirical research into assessment of young learners' foreign language competence in Slovenia, Croatia and the Czech Republic. With the help of an adapted questionnaire, we collected data from a non-random sample of primary and foreign language teachers who teach foreign languages at the primary level in these countries. The research shows that English as a foreign language is taught mostly by young teachers either primary specialists or foreign language teachers. These teachers most frequently use oral assessment/interviews or self-developed tests. Other more authentic types of assessment, such as language portfolios, are rarely used. The teachers most frequently assess speaking and listening skills, and they use assessment involving vocabulary the most frequently of all. However, there are significant differences in practice among the three countries

    Short Report : Outcomes for siblings associated with sub-groups of autistic children with intellectual disability identified by latent profile analysis

    Get PDF
    Background Recent research suggests that having a brother or sister with autism may contribute to increased positive or negative emotional or psychological impact on siblings. Aims To use a novel multidimensional data analysis method to further understand outcomes for siblings of autistic children. Methods and Procedures 318 siblings of children with a recorded autism diagnosis and an intellectual disability were included for latent profile analysis. Five variables (DBC disruptive and anxiety; VABS II communication, daily living, and socialization skills) were used to identify sub-groups of autistic children. Primary carers reported on sibling relationship quality (items from the Sibling Relationship Questionnaire warmth/closeness and conflict scales), and siblings’ behavioral and emotional problems. Outcomes and results The profile groups differed in their levels of ID coupled with disruptive behavior, emotional problems and adaptive skills. Profiles included a severe ID, low behavior and emotional problems and low adaptive skills group; a group with mild ID coupled with high adaptive skills and low emotional and behavioral problems; and a mild ID group with high emotional and behavioral problems. Conflict in the sibling relationship differed across the profile groups (F (4304) = 15.13, p < .001). Conclusions and implications Siblings of autistic children with the highest support needs were reported to have the lowest conflict in their relationships. Conversely, siblings of the autistic children with the highest levels of externalizing behaviors and anxiety were reported to have the highest levels of conflict in the sibling relationship

    Sibling adjustment and sibling relationships associated with clusters of needs in children with autism : a novel methodological approach

    Get PDF
    We tested a novel methodological approach to examine associations between characteristics of autistic children and outcomes for siblings. Cluster analysis was used to define five groups of children with autism (n = 168) based on autism symptoms, adaptive behavior, pro-social behavior, and behavior problems. Primary and secondary parent carers, and siblings themselves, reported on sibling relationship quality and psychological adjustment. Siblings of autistic children with a mild symptom profile, high levels of adaptive skills, but high internalizing and externalizing problems had the highest level of these problems themselves and more conflict in their relationship. Siblings of autistic children with the most complex support needs (adaptive skills deficits, severe autism symptoms) reported lower warmth relationships but not elevated internalizing and externalizing problems

    Inner tegument protein pUL37 of herpes simplex virus type 1 is involved in directing capsids to the trans-Golgi network for envelopment

    Get PDF
    Secondary envelopment of herpes simplex virus type 1 has been demonstrated as taking place at the trans-Golgi network (TGN). The inner tegument proteins pUL36 and pUL37 and the envelope glycoproteins gD and gE are known to be important for secondary envelopment. We compared the cellular localizations of capsids from a virus mutant lacking the UL37 gene with those of a virus mutant lacking the genes encoding gD and gE. Although wild-type capsids accumulated at the TGN, capsids of the pUL37− mutant were distributed throughout the cytoplasm and showed no association with TGN-derived vesicles. This was in contrast to capsids from a gD−gE− mutant, which accumulated in the vicinity of TGN vesicles, but did not colocalize with them, suggesting that they were transported to the TGN but were unable to undergo envelopment. We conclude that the inner tegument protein pUL37 is required for directing capsids to the TGN, where secondary envelopment occurs
    corecore