43 research outputs found

    Circadian clock regulates the shape and content of dendritic spines in mouse barrel cortex.

    Get PDF
    Circadian rhythmicity affects neuronal activity induced changes in the density of synaptic contacts and dendritic spines, the most common location of synapses, in mouse somatosensory cortex. In the present study we analyzed morphology of single- and double-synapse spines under light/dark (12:12) and constant darkness conditions. Using serial electron micrographs we examined the shape of spines (stubby, thin, mushroom) and their content (smooth endoplasmic reticulum, spine apparatus), because these features are related to the maturation and stabilization of spines. We observed significant diurnal and circadian changes in the shape of spines that are differentially regulated: single-synapse spines remain under circadian clock regulation, while changes of double-synapse spines are driven by light. The thin and mushroom single-synapse spines, regardless of their content, are more stable comparing with the stubby single-synapse spines that show the greatest diversity. All types of double-synapse spines demonstrate a similar level of stability. In light/dark regime, formation of new mushroom single-synapse spines occurs, while under constant darkness new stubby single-synapse spines are formed. There are no shape preferences for new double-synapse spines. Diurnal and circadian alterations also concern spine content: both light exposure and the clock influence translocation of smooth endoplasmic reticulum from dendritic shaft to the spine. The increasing number of mushroom single-synapse spines and the presence of only those mushroom double-synapse spines that contain spine apparatus in the light phase indicates that the exposure to light, a stress factor for nocturnal animals, promotes enlargement and maturation of spines to increase synaptic strength and to enhance the effectiveness of neurotransmission

    Identification of Secreted Exoproteome Fingerprints of Highly-Virulent and Non-Virulent Staphylococcus aureus Strains

    Get PDF
    Staphylococcus aureus is a commensal inhabitant of skin and mucous membranes in nose vestibule but also an important opportunistic pathogen of humans and livestock. The extracellular proteome as a whole constitutes its major virulence determinant; however, the involvement of particular proteins is still relatively poorly understood. In this study, we compared the extracellular proteomes of poultry-derived S. aureus strains exhibiting a virulent (VIR) and non-virulent (NVIR) phenotype in a chicken embryo experimental infection model with the aim to identify proteomic signatures associated with the particular phenotypes. Despite significant heterogeneity within the analyzed proteomes, we identified alpha-haemolysin and bifunctional autolysin as indicators of virulence, whereas glutamylendopeptidase production was characteristic for non-virulent strains.Staphopain C (StpC) was identified in both the VIR and NVIR proteomes and the latter fact contradicted previous findings suggesting its involvement in virulence. By supplementing NVIR, StpC-negative strains with StpC and comparing the virulence of parental and supplemented strains, we demonstrated that staphopain C alone does not affect staphylococcal virulence in a chicken embryo model

    Dyskusja

    Get PDF
    Oddajemy do r膮k Czytelnika kolejny tom z serii 鈥濸odstawowe idee i koncepcje w geografii鈥 pt. Dorobek polskiej geografii po konferencji w Rydzynie. Ocena krytyczna. [...] W艂a艣nie min臋艂o 30 lat od prze艂omowej dla polskiej geografii konferencji w Rydzynie (1983 r.). Mia艂a ona du偶e znaczenie dla przemian teorii i praktyki geografii. W Rydzynie zwr贸cono uwag臋 na odmienne od dotychczasowych mo偶liwo艣ci interpretacyjne rzeczywisto艣ci badawczej geografii rozwijane zw艂aszcza w krajach anglosaskich. W kontek艣cie tym przedstawiono nowe pola badawcze naszej dyscypliny zw艂aszcza nieistniej膮c膮 wcze艣niej geografi臋 spo艂eczn膮 jej podej艣cia radykalne i behawioralne oraz zaprezentowano perspektyw臋 humanistyczn膮 w badaniach geograficznych. Mimo trudno艣ci instytucjonalnych w przebijaniu si臋 efekt贸w tej innowacyjnej konferencji do teorii i empirii polskiej geografii, czas pokaza艂, 偶e jej dorobek nie zosta艂 zaprzepaszczony. Niniejszy tom sk艂ada si臋 z 13 prac, w kt贸rych autorzy podj臋li teoretyczn膮 refleksj臋 nad rol膮 konferencji w Rydzynie dla polskiej geografii oraz krytyczny namys艂 nad dorobkiem geografii po konferencji

    Development of children's hymenoptera venom allergy quality of life scale (CHVAQoLS)

    Get PDF
    BACKGROUND: Venom allergy is a rare but life-threatening disease and may have a considerable impact on the health-related quality of life (HRQoL) of patients, especially children. This paper presents development of the HRQoL scale for children and adolescents with Hymenoptera venom allergy (HVA). METHODS: The study sample consisted of 71 children, born between 1992 and 2000, who presented with a history of insect sting reaction when referred for consultation in the allergy center of Polish-American Children鈥檚 Hospital, Krakow, Poland, during the period from 2000 to 2010. The initial pool of 60 items - divided into 6 domains - was prepared. The items with intercorrelations higher than 0.7 were removed from each domain and then principal component analysis was conducted for each domain separately, to provide a one-dimensional subscale for each domain. Reliability of the subscales was assessed using Cronbach alpha coefficient in terms of Classical Test Theory and with rho coefficient in terms of Item Response Theory. The multidimensionality of the scale was tested using multi-trait scaling. RESULTS: Three to four items from each domain were subsequently selected to constitute six subscales. Rho coefficients for all the subscales reached 0.8, similar results were achieved with the Cronbach alpha coefficients. Multi-trait method showed that the majority of the items indicated stronger correlations with their own subscales than with other subscales, which proves that our constructed subscales measure different dimensions of HRQoL. CONCLUSIONS: The presented scale comprises high validity and reliability subscales measuring six dimensions of HRQoL related to Hymenoptera venom allergy in children and adolescents. Such information may be useful in everyday clinical practice
    corecore